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Displaying record number 2124

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MAb ID	PG9
HXB2 Location	gp160	gp160 Epitope Map
Author Location	gp120(126-196)
Epitope	(Discontinuous epitope)
Subtype	A
Ab Type	gp120 V2 // V2 glycan(V2g) // V2 apex, quaternary structure
Neutralizing	P (tier 2) View neutralization details
Contacts and Features	View contacts and features
Species (Isotype)	human(IgG1)
Patient	Donor 24
Immunogen	HIV-1 infection
Keywords	acute/early infection, ADCC, antibody binding site, antibody gene transfer, antibody generation, antibody interactions, antibody lineage, antibody polyreactivity, antibody sequence, assay or method development, autoantibody or autoimmunity, binding affinity, broad neutralizer, chimeric antibody, computational epitope prediction, elite controllers, escape, genital and mucosal immunity, germline, glycosylation, immunoprophylaxis, immunotherapy, junction or fusion peptide, memory cells, mother-to-infant transmission, neutralization, polyclonal antibodies, rate of progression, review, structure, subtype comparisons, vaccine antigen design, vaccine-induced immune responses, variant cross-reactivity

Notes

Showing 174 of 174 notes.

PG9: Analyses of all PDB HIV1-Env trimer (prefusion, closed) structures fulfilling certain parameters of resolution were performed to classify them on the basis of (a) antibody class which was informed by parental B cells as well as structural recognition, and (b) Env residues defining recognized HIV epitopes. Structural features of the 206 HIV epitope and bNAb paratopes were correlated with functional properties of the breadth and potency of neutralization against a 208-strain panel. bNAbs with >25% breadth of neutralization belonged to 20 classes of antibody with a large number of protruding loops and somatic hypermutation (SHM). HIV epitopes recognized placed the bNAbs into 6 categories (viz. V1V2, Glycan-V3, CD4-binding site, Silent face center, Fusion peptide and Subunit Interface). The epitopes contained high numbers of independent sequence segments and glycosylated surface area. PG9-Env formed a distinct group within the V1V2 category, Class PG9 and it has extensive D-gene contribution. Crystal structure data on B-cell culture identified PG9 Fab complexed to V1V2 region of strain ZM109 was found in PDB ID: 3U2S. Chuang2019 (antibody binding site, antibody interactions, neutralization, binding affinity, antibody sequence, structure, antibody lineage, broad neutralizer)
PG9: In an effort to identify new Env immunogens able to elicit bNAbs, this study looked at Envs derived from rare individuals who possess bNAbs and are elite viral suppressors, hypothesizing that in at least some people the antibodies may mediate durable virus control. The Env proteins recovered from these individuals may more closely resemble the Envs that gave rise to bNAbs compared to the highly diverse viruses isolated from normal progressors. This study identified a treatment-naive elite suppressor, EN3, whose serum had broad neutralization. The Env sequences of EN3 had much fewer polymorphisms, compared to those of a normal progressor, EN1, who also had broad serum neutralization. This result confirmed other reports of slower virus evolution in elite suppressors. EN3 Envelope proteins were unusual in that most possessed two extra cysteines within an elongated V1 region. The impact of the extra cysteines on the binding to bNAbs, virus infectivity, and sensitivity to neutralization suggested that structural motifs in V1 can affect infectivity, and that rare viruses may be prevented from developing escape. As part of this study, the neutralization of pseudotype viruses for EN3 Env clones was assayed for several bnAbs (PG9, PG16, PGT145, PGT121, PGT128, VRC01, 4E10, and 35O22). Hutchinson2019 (elite controllers, neutralization, vaccine antigen design, polyclonal antibodies)
PG9: The Chinese HIV Reference Laboratory produced 124 pseudoviruses from patients with subype B, BC, and CRF01 infections. These viruses were assigned to tiers based on their neutralization by a panel of patient sera. Their neutralization sensitivities were also measured against a panel of well-characterized mAbs (2F5, b12, 2G12, 4E10, 10E8, VRC01, VRC-CH31, CH01, PG9, PG16, PGT121, PGT126). Nie2020 (assay or method development, neutralization)
PG9: Extensive structural and biochemical analyses demonstrated that PGT145 achieves recognition and neutralization by targeting quaternary structure of the cationic trimer apex with long and unusually stabilized anionic β-hairpin HCDR3 loops. Compared to PGT145, PG9 showed increased breadth, neutralization potency, and maximum percentage neutralization (MPN) in the presence of complex/hybrid glycans. In BG505.Env.C2 alanine-scanning neutralization assays, PG9 had similar results as CH01, consistent with both CH01 and PG9 being representatives of hammerhead-class, and very dissimilar results to PGT145-like antibodies. Lee2017 (antibody binding site, neutralization)
PG9: Three vaccine regimens administered in guinea pigs over 200 weeks were compared for ability to elicit NAb polyclonal sera. While tier 1 NAb responses did increase with vaccination, tier 2 NAb heterologous responses did not. The 3 regimens were C97 (monovalent, Clade C gp140), 4C (tetravalent, 4 Clade C mosaic gp140s), ABCM (tetravalent, Clades A, B, C and mosaic gp140s). Polyclonal sera generated from the 4C and ABCM regimens, compared to the C97 regimen, were able to more successfully outcompete PG9 binding to gp140 antigens. Bricault2018 (antibody generation, vaccine-induced immune responses, polyclonal antibodies)
PG9: Novel Env pseudoviruses were derived from 22 patients in China infected with subtype CRF01_AE viruses. Neutralization IC50 was determined for 11 bNAbs: VRC01, NIH45-46G54W, 3BNC117, PG9, PG16, 2G12, PGT121, 10-1074, 2F5, 4E10, and 10E8. The CRF01_AE pseudoviruses exhibited different susceptibility to these bNAbs. Overall, 4E10, 10E8, and 3BNC117 neutralized all 22 env-pseudotyped viruses, followed by NIH45-46G54W and VRC01, which neutralized more than 90% of the viruses. 2F5, PG9, and PG16 showed only moderate breadth, while the other three bNAbs neutralized none of these pseudoviruses. Specifically, 10E8, NIH45-46G54Wand 3BNC117 showed the highest efficiency, combining neutralization potency and breadth. Mutations at position 160, 169, 171 were associated with resistance to PG9 and PG16, while loss of a potential glycan at position 332 conferred insensitivity to V3-glycan-targeting bNAbs. These results may help in choosing bNAbs that can be used preferentially for prophylactic or therapeutic approaches in China. Wang2018a (assay or method development, neutralization, subtype comparisons)
PG9: The authors mutated two conserved tyrosine (Y) residues within the V2 loop of gp120 Y177 and Y173, individually or in combination, by replacing them with either phenylalanine (F) or alanine (A) in a clade B, tier 1B HIV-1 Env protein (BaL), and in a number of tier 2 HIV-1 Envs from different clades, namely, BG505 (clade A), JR-FL and JR-CSF (clade B), and CM244 (clade E). A consistent hierarchy of neutralization sensitivity was seen among the mutants, with a greater impact of Y177 over Y173 single mutations, of double over single mutations, and of A over F substitutions. The double-alanine mutation in mutant HIV-1 BaL, Y173A Y177A, increased sensitivity to all the weakly neutralizing MAbs tested and even rendered the virus sensitive to non-neutralizing antibodies against the CD4 binding site, such as F105, 654-30D, and b13. When tested against bNAbs instead, there was a trend to decrease neutralization sensitivity compared to WT, with the exception of N6, PGT151, 10E8, and 2G12, for which there was no change, and of 2F5 and 4E10, which were more effective against the mutant compared to the WT. Guzzo2018 (antibody binding site, binding affinity)
PG9: To reduce local V2 flexibility and improve the binding of V2-dependent bNAbs and germline precursor bNAbs, the authors designed BG505 SOSIP.664 trimer variants whose V1 and V2 domains were stabilized by introducing disulfide bonds either within the V2 loop or between the V1 and V2 loops. The resulting SOSIP trimer variants — E153C/K178C, E153C/K178C/G152E and I184C/E190C — have improved reactivity with V2 bNAbs and their inferred germline precursors and are more sensitive to neutralization by V2 bNAbs. PGT121, PG9, PG16, and CH01 bound better to the E153C/R178C/G152E mutant than to SOSIP.664. The I184C/E190C mutant bound all the V2 bNAbs (PG9, PG16, PGT145, VRC26.09, and CH01) better than SOSIP.664. I184C/E190C was more sensitive to neutralization by V2 bNAbs compared with BG505 (by 5-fold for PG9, 3-fold for PG16, 6-fold for CH01, and 3-fold for PGDM1400). deTaeye2019 (antibody interactions, variant cross-reactivity, binding affinity, structure, broad neutralizer)
PG9: The authors used genome-editing techniques (CRISPR-Cas9) to modify HIV specific B cell receptors. In particular, they replaced the heavy chain variable region in B cell lines with that from the HIV broadly neutralizing antibody PG9. The chimeric PG9 antibodies they created could neutralized one or more of the PG9-sensitive viruses, and most neutralized multiple viruses from different clades in a global panel, although none of the chimeric antibodies were as broadly neutralizing as the original PG9 HC/LC pair. Voss2019 (neutralization, antibody sequence, broad neutralizer, chimeric antibody)
PG9: This study looks at the role of somatic mutations within antibody variable and framework regions (FWR) in bNAbs and how these mutations alter thermostability and neutralization as the Ab lineage reaches maturation. The emergence and selection of different mutations in the complementarity-determining and framework regions are necessary to maintain a balance between antibody function and stability. The study shows that all major classes of bnAbs (DH2070, CH103, CH235 etc.) have lower thermostability than their corresponding inferred UCA antibodies. Henderson2019 (neutralization, antibody lineage, broad neutralizer)
PG9: Two HIV-1-infected individuals, VC10014 and VC20013, were monitored from early infection until well after they had developed broadly neutralizing activity. The bNAb activity developed about 1 year after infection and mapped to a single epitope in both subjects. Isolates from each subject, taken at five different time points, were tested against monoclonal bNAbs: VRC01, B12, 2G12, PG9, PG16, 4E10, and 2F5. In subject VC10014, the bNAb activity developed around 1 year postinfection and targeted an epitope that overlaps the CD4-BS and is similar to (but distinct from) bNAb HJ16. In the case of VC20013, the bNAb activity targeted a novel epitope in the MPER that is critically dependent on residue 677 (mutation K677N). Sather2014 (neutralization, broad neutralizer)
PG9: This study demonstrated that bNAb signatures can be utilized to engineer HIV-1 Env vaccine immunogens eliciting Ab responses with greater neutralization breadth. Data from four large virus panels were used to comprehensively map viral signatures associated with bNAb sensitivity, hypervariable region characteristics, and clade effects. The bNAb signatures defined for the V2 epitope region were then employed to inform immunogen design in a proof-of-concept exploration of signature-based epitope targeted (SET) vaccines. V2 bNAb signature-guided mutations were introduced into Env 459C to create a trivalent vaccine which resulted in increased breadth of NAb responses compared with Env 459C alone. PG9 was used as V2 Ab and Clade B was resistant to PG9. Based on structural contacts for PG9, phylogenetically corrected signatures and statistical support for other V2 Abs contacts were analyzed. Bricault2019 (antibody binding site, vaccine antigen design, computational epitope prediction, broad neutralizer)
PG9: The influence of a V2 State 2/3-stabilizing Env mutation, L193A, on ADCC responses mediated by sera from HIV-1-infected individuals was evaluated. Conformations spontaneously sampled by the Env trimer at the surface of infected cells had a significant impact on ADCC. State 1-preferring ligand PG9 recognized L193A variants of CH58 and CH77 IMCs with less efficiently compared to the WT. Prevost2018 (ADCC)
PG9: A simple method to quantify and compare serum neutralization probabilities in described. The method uses logistic regression to model the probability that a serum neutralizes a virus with an ID50 titer above a cutoff. The neutralization potency (NP) identifies where the probabilities of neutralizing and not neutralizing a virus are equal and is not absolute as it depends on the ID50 cutoff. It provides a continuous measure for sera, which builds upon established tier categories now used to rate virus sensitivity. These potency comparisons are similar to comparing geometric mean neutralization titers, but instead are represented in tier-like terms. Increasing the number of bNAbs increases NP and slope, where the higher the slope, the sharper the boundary (lower scatter) between viruses neutralized and not neutralized. PG9 was used in analysis of monoclonal bNAb combinations. Hraber2018 (assay or method development, neutralization)
PG9: This review summarizes current advances in antibody lineage-based design and epitope-based vaccine design. Antibody lineage-based design is described for VRC01, PGT121 and PG9 antibody classes, and epitope-based vaccine design is described for the CD4-binding site, as well as fusion peptide and glycan-V3 cites of vulnerability. Kwong2018 (antibody binding site, vaccine antigen design, vaccine-induced immune responses, review, antibody lineage, broad neutralizer, junction or fusion peptide)
PG9: This review discusses the identification of super-Abs, where and how such Abs may be best applied and future directions for the field. PG9, a prototype super-Ab, was isolated from direct functional screening of B cell clones from an HIV elite neutralizer and was an order of magnitude more potent than first-generation bNAbs. Recently recombinant native-like HIV Env trimers have enabled the identification of exceptionally potent ‘PG9-class’ bNAbs e.g., PG16, PGT141-144, CH01-04, PGDM1400–1412 and CAP256-VRC26.01-12. Antigenic region V2 apex (Table:1) Walker2018 (antibody binding site, review, broad neutralizer)
PG9: The authors selected an optimal panel of diverse HIV-1 envelope glycoproteins to represent the antigenic diversity of HIV globally in order to be used as antigen candidates. The selection was based on genetic and geographic diversity, and experimentally and computationally evaluated humoral responses. The eligibility of the envelopes as vaccine candidates was evaluated against a panel of antibodies for breadth, affinity, binding and durability of vaccine-elicited responses. The antigen panel was capable of detecting the spectrum of V2-specific antibodies that target epitopes from the V2 strand C (V2p), the integrin binding motif in V2 (V2i), and the quaternary epitope at the apex of the trimer (V2q). Yates2018 (vaccine antigen design, vaccine-induced immune responses, binding affinity)
PG9: The effects of 16 glycoengineering (GE) methods on the sensitivities of 293T cell-produced pseudoviruses (PVs) to a large panel of bNAbs were investigated. Some bNAbs were dramatically impacted. PG9 and were up to 30-fold more potent against PVs produced with co-transfected α-2,6 sialyltransferase. PGT151 and PGT121 were more potent against PVs with terminal SA removed. 35O22 and CH01 were more potent against PV produced in GNT1-cells. The effects of GE on bNAbs VRC38.01, VRC13 and PGT145 were inconsistent between Env strains, suggesting context-specific glycan clashes. Overexpressing β-galactosyltransferase during PV production 'thinned' glycan coverage, by replacing complex glycans with hybrid glycans. This impacted PV sensitivity to some bNAbs. Maximum percent neutralization by excess bnAb was also improved by GE. Remarkably, some otherwise resistant PVs were rendered sensitive by GE. Germline-reverted versions of some bnAbs usually differed from their mature counterparts, showing glycan indifference or avoidance, suggesting that glycan binding is not germline-encoded but rather, it is gained during affinity maturation. Overall, these GE tools provided new ways to improve bnAb-trimer recognition that may be useful for informing the design of vaccine immunogens to try to elicit similar bnAbs. Crooks2018 (vaccine antigen design, antibody lineage)
PG9: A panel of bnAbs were studied to assess ongoing adaptation of the HIV-1 species to the humoral immunity of the human population. Resistance to neutralization is increasing over time, but concerns only the external glycoprotein gp120, not the MPER, suggesting a high selective pressure on gp120. Almost all the identified major neutralization epitopes of gp120 are affected by this antigenic drift, suggesting that gp120 as a whole has progressively evolved in less than 3 decades. Bouvin-Pley2014 (neutralization)
PG9: A rare glycan hole at the V2 apex is enriched in HIV isolates neutralized by inferred precursors of prototype V2-apex bNAbs. To investigate whether this feature could focus neutralizing responses onto the apex bnAb region, rabbits were immunized with soluble trimers adapted from these Envs. Potent autologous tier 2 neutralizing responses targeting basic residues in strand C of the V2 region, which forms the core epitope for V2-apex bnAbs, were observed. Neutralizing monoclonal antibodies (mAbs) derived from these animals display features promising for subsequent broadening of the response. Four human anti-V2 bnAbs (PG9, CH01, PGT145, and CAP256.09) were used as a basis of comparison. Voss2017 (vaccine antigen design)
PG9: This study describes the generation of CHO cell lines stably expressing the following vaccine Env Ags: CRF01_AE A244 Env gp120 protein (A244.AE) and 6240 Env gp120 protein (6240.B). The antigenic profiles of the molecules were assessed with a panel of well-characterized mAbs recognizing critical epitopes and glycosylation analysis confirming previously identified sites and revealing unknown sites at non-consensus motifs. A244.AE gp120 showed low level of binding to PG9 in ELISA EC50 and Surface Plasmon Resonance (SPR) assays. 6240.B gp120 exhibited binding to PG9. Wen2018 (glycosylation, vaccine antigen design)
PG9: The prophylactic and therapeutic potential of an engineered single gene–encoded tandem bispecific immunoadhesin (IA) molecule BiIA-SG was studied. Before engineering BiIAs, codon-optimized scFvs of bNAbs PG9, PG16, PGT128, VRC01, and Hu5A8 were synthesized. The VL/VH domain of each scFv was engineered as a corresponding IA by fusion with human IgG1-Fc to generate IA-PG9, IA-PG16, IA-PGT128, IA-VRC01, and IA-Hu5A8. While all IAs exhibited specific anti–HIV-1 activity, only IA-PGT128 displayed similar potency and the same sigmoidal slope of 100% neutralization as previously described for the native PGT128, and IA-PGT128 in combination with IA-Hu5A8 exhibited the best synergistic effect based on computational synergy volumes. IA-PGT128 and IA-Hu5A8 were therefore used for BiIA construction. Wu2018
PG9: Assays of poly- and autoreactivity demonstrated that broadly neutralizing NAbs are significantly more poly- and autoreactive than non-neutralizing NAbs. PG9 is polyreactive, but not autoreactive. Liu2015a (autoantibody or autoimmunity, antibody polyreactivity)
PG9: Panels of C clade pseudoviruses were computationally downselected from the panel of 200 C clade viruses defined by Rademeyer et al. 2016. A 12-virus panel was defined for the purpose of screening sera from vaccinees. Panels of 50 and 100 viruses were defined as smaller sets for use in testing magnitude and breadth against C clade. Published neutralization data for 16 mAbs was taken from CATNAP for the computational selections: 10-1074, 10-1074V, PGT121, PGT128, VRC26.25, VRC26.08, PGDM1400, PG9, PGT145, VRC07-523, 10E8, VRC13, 3BNC117, VRC07, VRC01, 4E10. Hraber2017 (assay or method development, neutralization)
PG9: A panel of 14 pseudoviruses of subtype CRF01_AE was developed to assess the neutralization of several neutralizing antibodies (b12, PG9, PG16, 4E10, 10E8, 2F5, PGT121, PGT126, 2G12). Neutralization was assessed in both TZM-bl and A3R5 cell-based assays. Most viruses were more susceptible to mAb-neutralization in A3R5 than in the TZM-bl cell-based assay. The increased neutralization sensitivity observed in the A3R5 assay was not linked to the year of virus transmission or to the stages of infection, but chronic viruses from the years 1990-92 were more sensitive to neutralization than the more current viruses, in both assays. Chenine2018 (assay or method development, neutralization, subtype comparisons)
PG9: The immunologic effects of mutations in the Env cytoplasmic tail (CT) that included increased surface expression were explored using a vaccinia prime/protein boost protocol in mice. After vaccinia primes, CT- modified Envs induced up to 7-fold higher gp120-specific IgG, and after gp120 protein boosts, they elicited up to 16-fold greater Tier-1 HIV-1 neutralizing antibody titers. Hogan2018 (vaccine antigen design)
PG9: Env trimers were engineered with selective deglycosylation around the CD4 binding site to see if they could be useful vaccine antigens. The neutralization of glycan-deleted trimers was tested for a set of bnAbs (PG9, PGT122, PGT135, b12, CH103, HJ16, VRC01, VRC13, PGT151, 8ANC195, 35O22), and the antigens elicited potent neutralization based on the CD4 supersite. A crystal structure was made of one of these Env trimers bound to Fabs 35O22 and 3H+109L. Guinea pigs vaccinated with these antigens achieved neutralization of deglycosylated Envs. Glycan-deleted Env trimers may be useful as priming antigens to increase the frequency of CD4 site-directed antibodies. Zhou2017 (glycosylation, neutralization, vaccine antigen design, vaccine-induced immune responses)
PG9: Env from of a highly neutralization-resistant isolate, CH120.6, was shown to be very stable and conformationally-homogeneous. Its gp140 trimer retains many antigenic properties of the intact Env, while its monomeric gp120 exposes more epitopes. Thus trimer organization and stability are important determinants for occluding epitopes and conferring resistance to antibodies. Among a panel of 21 mAbs, CH120.6 was resistant to neutralization by all non-neutralizing and strain-specific mAbs, regardless of the location of their epitopes. It was weakly neutralized by several broadly-neutralizing mAbs (VRC01, NIH45-46, 12A12, PG9, PG16, PGT128, 4E10, and 10E8), and well neutralized by only 2 (PGT145 and 10-1074). Cai2017 (neutralization)
PG9: A panel of mAbs (2G12, VRC01, HJ16, 2F5, 4E10, 35O22, PG9, PGT121, PGT126, 10-1074) was tested to compare their efficacy in cell-free versus cell-cell transmission. Almost all bNAbs (with the exception of anti-CD4 mAb Leu3a) blocked cell-free infection with greater potency than cell-cell infection, and showed greater potency in neutralization of cell-free viruses. The lower effectiveness on neutralization was particularly pronounced for transmitted/founder viruses, and less pronounced for chronic and lab-adapted viruses. The study highlights that the ability of an antibody to inhibit cell-cell transmission may be an important consideration in the development of Abs for prophylaxis. Li2017 (immunoprophylaxis, neutralization)
PG9: The next generation of a computational neutralization fingerprinting (NFP) being used as a way to predict polyclonal Ab responses to HIV infection is presented. A new panel of 20 pseudoviruses, termed f61, was developed to aid in the assessment of experimental neutralization. This panel was used to assess 22 well-characterized bNAbs and mixtures thereof (HJ16, VRC01, 8ANC195, IGg1b12, PGT121, PGT128, PGT135, PG9, PGT151, 35O22, 10E8, 2F5, 4E10, VRC27, VRC-CH31, VRC-PG20, PG04, VRC23, 12A12, 3BNC117, PGT145, CH01). The new algorithms accurately predicted VRC01-like and PG9-like antibody specificities. Doria-Rose2017 (neutralization, computational epitope prediction)
PG9: This review focuses on the potential role of HIV-1-specific NAbs in preventing HIV-1 infection. Several NAbs have provided protection from infection in SHIV challenge studies in primates: b12, VRC01, VRC07-523LS, 3BNC117, PG9, PGT121, PGT126, 10-1074, 2G12, 4E10, 2F5, 10E8. Pegu2017 (immunoprophylaxis, review)
PG9: The ability of neutralizing and nonneutralizing mAbs to block infection in models of mucosal transmission was tested. Neutralization potency did not fully predict activity in mucosal tissue. CD4bs-specific bNAbs, in particular VRC01, blocked HIV-1 infection across all cellular and tissue models. MPER (2F5) and outer domain glycan (2G12) bNAbs were also efficient in preventing infection of mucosal tissues, while bNAbs targeting V1-V2 glycans (PG9 and PG16) were more variable. Non-nAbs alone and in combinations, were poorly protective against mucosal infection. The protection provided by specific bNAbs demonstrates their potential over that of nonneutralizing antibodies for preventing mucosal entry. PG9 and PG16 were selected to represent mAbs of the V1-V2 glycan class. Cheeseman2017 (genital and mucosal immunity, immunoprophylaxis)
PG9: To understand HIV neutralization mediated by the MPER, antibodies and viruses were studied from CAP206, a patient known to produce MPER-targeted neutralizing mAbs. 41 human mAbs were isolated from CAP206 at various timepoints after infection, and 4 macaque mAbs were isolated from animals immunized with CAP206 Env proteins. Two rare, naturally-occuring single-residue changes in Env were identified in transmitted/founder viruses (W680G in CAP206 T/F and Y681D in CH505 T/F) that made the viruses less resistant to neutralization. The results point to the role of the MPER in mediating the closed trimer state, and hence the neutralization resistance of HIV. CH58 was one of several mAbs tested for neutralization of transmitted founder viruses isolated from clade C infected individuals CAP206 and CH505, compared to T/F viruses containing MPER mutations that confer enhanced neutralization sensitivity. Bradley2016a (neutralization)
PG9: This study performed cyclical permutation of the V1 loop of JRFL in order to develop better gp120 trimers to elicit neutralizing antibodies. Some mutated trimers showed improved binding to several mAbs, including VRC01, VRC03, VRC-PG04, PGT128, PGT145, PGDM1400, b6, and F105. Guinea pigs immunized with prospective trimers showed improved neutralization of a panel of HIV-1 pseudoviruses. Binding of PG9 to JRFL was abolished by mutations N156K or N160K. Kesavardhana2017 (vaccine antigen design, vaccine-induced immune responses)
PG9: This study investigated the ability of native, membrane-expressed JR-FL Env trimers to elicit NAbs. Rabbits were immunized with virus-like particles (VLPs) expressing trimers (trimer VLP sera) and DNA expressing native Env trimer, followed by a protein boost (DNA trimer sera). N197 glycan- and residue 230- removal conferred sensitivity to Trimer VLP sera and DNA trimer sera respectively, showing for the first time that strain-specific holes in the "glycan fence" can allow the development of tier 2 NAbs to native spikes. All 3 sera neutralized via quaternary epitopes and exploited natural gaps in the glycan defenses of the second conserved region of JR-FL gp120. A bioinformatics analysis suggested shared features of one of the trimer VLP sera and monoclonal antibody PG9, consistent with its trimer-dependency. PG9 was 1 of 2 reference PG9-like bNAbs - PG9 and PGT145. Crooks2015 (glycosylation, neutralization)
PG9: Env residue N197 on the BG505-SOSIP trimer was mutated to test the effect of its glycosylation on the binding kinetics of CD4BS and other mAbs. Removal of the glycan had little effect on the overall structure of the molecule. Its removal resulted in increased binding of CD4 and CD4BS antibodies (VRC01, VRC03, V3-3074), but little effect on bNAbs targeting other epitopes (PG9, PG16, PGT145, 17b, A32, 2G12, PGT121, PGT126). Two CD4BS-binding antibodies tested (b12, F105) had insufficient breadth to bind the BG505-SOSIP trimer. Removal of the N197 glycan may allow for the development of better SOSIP immunogens, particularly to elicit CD4BS-specific Abs. Liang2016 (glycosylation, vaccine antigen design)
PG9: Binding of PG9 to properly folded and glycosylated fragments of Env V1/V2 (scaffolds) is described. Scaffolds from 3 different clades of HIV-1 bound to PG9 with high affinity. Mutations I169K, E172V, T161M, N156I, S164G, D167G (includng those outside of the antibody contact region) improved binding. Morales2016 (antibody binding site, vaccine antigen design)
PG9: Chimeric antigen receptors (CAR), i.e., fusion proteins made from single-chain antibodies, may be a useful approach to immunotherapy. A set of mAbs were chosen based on their binding to a variety of sites on Env and availability of antibody sequences. The chimeric receptors were created by fusing the antibody's heavy chain, light chain, and two signaling domains into a single molecule. All 7 antibodies used to make the chimeric receptors (10E8, 3BNC117, PGT126, VRC01, X5, PGT128, PG9) showed specific killing of HIV-1 infected cells and suppression of viral replication against a panel of HIV-1 strains. Ali2016 (immunotherapy, chimeric antibody)
PG9: This review classified and mapped the binding regions of 32 bNAbs isolated 2010-2016. Wu2016 (review)
PG9: This study produced Env SOSIP trimers for clades A (strain BG505), B (strain JR-FL), and G (strain X1193). Based on simulations, the MAb-trimer structures of all MAbs tested needed to accommodate at least one glycan, including both antibodies known to require specific glycans (PG9, PGT121, PGT135, 8ANC195, 35O22) and those that bind the CD4-binding site (b12, CH103, HJ16, VRC01, VRC13). A subset of monoclonal antibodies bound to glycan arrays assayed on glass slides (VRC26.09, PGT121, 2G12, PGT128, VRC13, PGT151, 35O22), while most of the antibodies did not have affinity for oligosaccharide in the context of a glycan array (PG9, PGT145, PGDM1400, PGT135, b12, CH103, HJ16, VRC16, VRC01, VRC-PG04, VRC-CH31, VRC-PG20, 3BNC60, 12A12, VRC18b, VRC23, VRC27, 1B2530, 8ANC131, 8ANC134, 8ANC195). Stewart-Jones2016 (antibody binding site, glycosylation, structure)
PG9: This study assessed the ADCC activity of antibodies of varied binding types, including CD4bs (b6, b12, VRC01, PGV04, 3BNC117), V2 (PG9, PG16), V3 (PGT126, PGT121, 10-1074), oligomannose (2G12), MPER (2F5, 4E10, 10E8), CD4i (17b, X5), C1/C5 (A32, C11), cluster I (240D, F240), and cluster II (98-6, 126-7). ADCC activity was correlated with binding to Env on the surfaces of virus-infected cells. ADCC was correlated with neutralization, but not always for lab-adapted viruses such as HIV-1 NLA-3. vonBredow2016 (ADCC)
PG9: This review summarizes representative anti-HIV MAbs of the first generation (2G12, b12, 2F5, 4E10) and second generation (PG9, PG16, PGT145, VRC26.09, PGDM1400, PGT121, PGT124, PGT128, PGT135, 10-1074, VRC01, 3BNC117, CH103, PGT151, 35O22, 8ANC195, 10E8). Structures, epitopes, VDJ usage, CDR usage, and degree of somatic hypermutation are compared among these antibodies. The use of SOSIP trimers as immunogens to elicit B-cell responses is discussed. Burton2016 (review, structure)
PG9: HIV-1 bNAb eptiope networks were predicted using 4 algorithms informed by neutralization assays using 282 Env from multiclade viruses. Patch clusters of possible Ab epitope regions were tested for significant sensitivity by site-directed mutagenesis. Epitope (Ab binding site) networks of critical Env residues for 21 bNAb (b12, PG9, PG16, PGT121, PGT122, PGT123, PGT125, PGT126, PGT127, PGT128, PGT130, PGT131, PGT135, PGT136, PGT137, PGT141, PGT142, PGT143, PGT144, PGT145 and PGV04) were delineated and found to be located mostly in variable loops of gp120, particularly in V1/V2. Evans2014 (antibody binding site, computational epitope prediction)
PG9: Two stable homogenous gp140 Env trimer spikes, Clade A 92UG037.8 Env and Clade C C97ZA012 Env, were identified. 293T cells stably transfected with either presented fully functional surface timers, 50% of which were uncleaved. A panel of neutralizing and non-neutralizing Abs were tested for binding to the trimers. V1/V2 glycan bNAb PG9 bound cell surface tightly whether the trimer contained its C-terminal or not, and was competed out by sCD4. It was able to neutralize the 92UG037.8 HIV-1 isolate. Chen2015 (neutralization, binding affinity)
PG9: Factors that independently affect bNAb induction and evolution were identified as viral load, length of untreated infection and viral diversity. Ethnically, black subjects induced bNAbs more than white subjects, but this did not correlate with type of Ab response. Fingerprint analyses of induced bNAbs showed strong subtype-dependency, with subtype B inducing significantly higher levels of CD4bs Abs and non-subtype B inducing V2-glycan specific Abs. Of the 239 bNAb antibody inducers found from 4,484 HIV-1 infected subjects,the top 105 inducers' neutralization fingerprint and epitope specificity was determined by comparison to the following antibodies - PG9, PG16, PGDM1400, PGT145 (V2 glycan); PGT121, PGT128, PGT130 (V3 glycan); VRC01, PGV04 (CD4bs) and PGT151 (interface) and 2F5, 4E10, 10E8 (MPER). Rusert2016 (neutralization, broad neutralizer)
PG9: PGT145 was used to positively isolate a subtype B Env trimer immunogen, B41 SOSIP.664-D7324, that exists in two conformations, closed and partially open. bNAbs tested against the trimer were able to neutralize the B41 pseudovirus with a wide range of potencies. All tested non-NAbs did not neutralize B41 (IC₅₀ >50µg/ml). V1/V2 glycan bNAb, PG9, neutralized B41 psuedovirus and bound B41 trimer well. Pugach2015
PG9: The first generation of HIV trimer soluble immunogens, BG505 SOSIP.664 were tested in a mouse model for generation of nAb to neutralization-resistant circulating HIV strains. No such NAbs were induced, as mouse Abs targeted the bottom of soluble Env trimers, suggesting that the glycan shield of Env trimers is impenetrable to murine B cell receptors and that epitopes at the trimer base should be obscured in immunogen design in order to avoid non-nAb responses. Association and dissociation of known anti-trimer bNAbs (VRC01, PGT121, PGT128, PGT151, PGT135, PG9, 35O22, 3BC315 and PGT145) were found to be far greater than murine generated non-NAbs. Hu2015
PG9: A comprehensive antigenic map of the cleaved trimer BG505 SOSIP.664 was made by bNAb cross-competition. Epitope clusters at the CD4bs, quaternary V1/V2 glycan, N332-oligomannose patch and new gp120-gp41 interface and their interactions were delineated. Epitope overlap, proximal steric inhibition, allosteric inhibition or reorientation of glycans were seen in Ab cross-competition. Thus bNAb binding to trimers can affect surfaces beyond their epitopes. PG9, PG16 and PG145, all V1/V2 glycan trimer apex bNAbs, were strongly, reciprocally competitive with one another. V3 glycan bNAbs PGT121, PGT122, PGT123 inhibited binding of PG9 strongly, but in a non-reciprocal manner. Derking2015 (antibody interactions, neutralization, binding affinity, structure)
PG9: Two clade C recombinant Env glycoprotein trimers, DU422 and ZM197M, with native-like structural and antigenic properties involving epitopes against all known classes of bNAbs, were produced and characterized. These Clade C trimers (10-15% of which are in a partially open form) were more like B41 Clade B trimers which have 50-75% trimers in the partially open configuration than like B505 Clade B trimers, almost 100% in the closed, prefusion state. The Clade C trimers are weakly reactive with the V1/V2 glycan bNAb, PG9, and while neutralization of the DU422 pseudotyped virus is robust, that of the ZM197M pseudovirus is moderate. Julien2015 (assay or method development, structure)
PG9: HIV-1 escape from the N332-glycan dependent bNAb, PGT135, developed in an elite controller but without change to the PGT135-binding Env epitope itself. Instead an insertion increasing V1 length by up to 21 residues concomitant with an additional 1-3 glycans and 2-4 cysteines shields the epitope from PGT135. The majority of viruses tested developed a 14-fold resistance to PGT135 from month 7 to 11. In comparison, no significant difference in HIV-1 against bNAb PG9 was seen. vandenKerkhof2016 (elite controllers, neutralization, escape)
PG9: A new trimeric immunogen, BG505 SOSIP.664 gp140, was developed that bound and activated most known neutralizing antibodies but generally did not bind antibodies lacking neuralizing activity. This highly stable immunogen mimics the Env spike of subtype A transmitted/founder (T/F) HIV-1 strain, BG505. Anti-V1/V2 glycan bNAb PG9, neutralized BG505.T332N, the pseudoviral equivalent of the immunogen BG505 SOSIP.664 gp140, and was shown to recognize and bind the immunogen too. Sanders2013 (assay or method development, neutralization, binding affinity)
PG9: This review discusses an array of methods to engineer more effective bNAbs for immunotherapy. Antibody PG9 was mentioned as an example of engineering through rational mutations; PG9-N100(F)Y stabilizes the CDR-H3 in the active conformation, thus improving neutralization. Hua2016 (immunotherapy, review)
PG9: Site-specific analysis of N-glycosylation sites of a soluble recombinant trimerBG505 SOSIP.664 is presented. Neutralization profiles for V1V2 Ab, PG9, to multiple epitopes were determined. Removing the N156 or N160 glycans from either of the BG505 test viruses reduced the neutralization activities of PG9. Behrens2016 (antibody binding site, glycosylation)
PG9: A mathematical model was developed to predict the Ab concentration at which antibody escape variants outcompete their ancestors, and this concentration was termed the mutant selection window (MSW). The MSW was determined experimentally for 12 pairings of diverse HIV strains against 7 bnAbs (b12, 2G12, PG9, PG16, PGT121, PGT128, 2F5). The neutralization of of PG9 was assayed against 5 resistant and 5 sensitive strains. Magnus2016 (neutralization, escape)
PG9: A panel of Env-specific mAbs was isolated from 6 HIV1-infected lactating women. Antibodies in colostrum may help prevent mucosal infection of the infant, so this study aimed to define milk IgGs for future vaccination strategies to reduce HIV transmission during lactation. Despite the high rate of VH_1-69 usage among colostrum Env specific B cells, it did not correlate with distinct gp120 epitope specificity or function. PG9 was compared to the newly-derived mAbs; it had no cross-reactivity with gut bacteria, and tested negative in two tests of autoreactivity. Jeffries2016 (antibody polyreactivity)
PG9: The study detailed binding kinetics of the interaction between BG505 SOSIP.664 trimer or its variants (gp120 monomer; first study of disulfide-stabilized variant gp120-gp41_ECTO protomer) and several mAbs, both neutralizing (VRC01, PGV04, PG9, PG16, PGT121, PGT122, PGT123, PGT145, PGT151, 2G12) and non-neutralizing (b6, b12, 14e, 19b, F240). V1V2 quarternary-dependent epitope-binding bNAb, PG9, bound trimer best, but less well to protomer and BG505 gp120's monomer. Yasmeen2014 (antibody binding site, assay or method development)
PG9: Neutralization breadth in 157 antiretroviral-naive individuals infected for less than 1 year post-infection was studied and compared to a cohort of 170 untreated chronic patients. A range of neutralizing activities was observed with a panel of six recombinant viruses from five different subtypes. Some sera were broadly reactive, predominantly targeting envelope epitopes within the V2 glycan-dependent region. The Env neutralization breadth was positively associated with time post infection. PG9 has been used as a control in detection of glycan-dependent HIV-1 neutralizing sera. Sanchez-Merino2016 (neutralization, acute/early infection)
PG9: A new, current, mostly tier2 panel of 200 C-clade Env-psuedotyped viruses from early (< 100d) infection in southern Africa was used to assess antibody responses to natural infection and to vaccines. Viruses were assayed with bNAbs targeting the V2 glycan (PG9, VRC26.25), the MPER site (4E10), the CD4 binding site (VRC01), and the V3/C3 glycan site (PGT128). For 4E10 (and all other Abs besides PGT128) there was no significant difference in neutralization between pre-seroconversion and post-seroconversion viruses. Viruses collected pre-seroconversion were more resistant to neutralization by serum than those post-seroconversion. As the epidemic matured over 13 years, viruses also became more resistant to mAbs tested. Rademeyer2016 (assay or method development, neutralization)
PG9: The sequential development of three distinct bnAb responses within a single host, CAP257, over 4.5 years of infection has been described. It showed how escape from the first wave of Abs targeting V2 exposed a second site that was the stimulus for a new wave of glycan dependent bnAbs against the CD4 binding site. These data highlighted how Ab evolution in response to viral escape mutations served to broaden the host immune response to two epitopes. A third wave of neutralization targeting an undefined epitope that did not appear to overlap with the four known sites of vulnerability on the HIV-1 envelope has been reported. These data supported the design of templates for sequential immunization strategies. Wibmer2013 (escape)
PG9: This study examined the neutralization of group N, O, and P primary isolates of HIV-1 by diverse antibodies. Cross-group neutralization was observed only with the bNAbs targeting the N160 glycan-V1/V2 site. Four group O isolates, 1 group N isolate, and the group P isolates were neutralized by PG9 and/or PG16 or PGT145 at low concentrations. None of the non-M primary isolates were neutralized by bNAbs targeting other regions, except 10E8, which weakly neutralized 2 group N isolates, and 35O22 which neutralized 1 group O isolate. Bispecific bNAbs (PG9-iMab and PG16-iMab) very efficiently neutralized all non-M isolates with IC₅₀ below 1 ug/mL, except for 2 group O strains. Anti V1/V2 bNAb PG9 was able to neutralize 5/16 tested non-M primary isolates at an IC₅₀< 10µg/ml, 2 of them highly with a value under 1 µg/ml and 3 moderately. Morgand2015 (neutralization, subtype comparisons)
PG9: The neutralization of 14 bnAbs was assayed against a global panel of 12 or 17 Env pseudoviruses. From IC₅₀, IC₈₀, IC₉₀, and IC₉₉ values, the slope of the dose-response curve was calculated. Each class of Ab had a fairly consistent slope. Neutralization breadth was strongly correlated with slope. An IIP (Instantaneous Inhibitory Potential) value was calculated, based on both the slope and IC50, and this value may be predictive of clinical efficacy. PG9, a V2-glycan bnAb belonged to a group with slopes <1. Webb2015 (neutralization)
PG9: This study evaluated the binding of 15 inferred germline (gl) precursors of bNAbs that are directed to different epitope clusters, to 3 soluble native-like SOSIP.664 Env trimers - BG505, B41 and ZM197M. The trimers bound to some gl precursors, particularly those of V1V2-targeted Abs. These trimers may be useful for designing immunogens able to target gl precursors. V1/V2 apex-binding gl-PG9 precursor bound to 2/3 trimers, BG505 and ZM197M. Sliepen2015 (binding affinity, antibody lineage)
PG9: Computational modeling was used to examine antibody recognition of glycans, using a V1V2 bNAb (PG9) and a V3 bnAb (PGT128). Both PG9 and PGT128 have a long CDR H3 loop that can penetrate the glycan shield and form interactions with gp120. The modeling results showed that the tip of the CDR H3 loop is flexible in the free antibodies and is able to move within the bound conformation, which likely increases the penetrability of the glycan shield. Qi2016 (glycosylation)
PG9: To test whether NAbs can inhibit viral transmission through mucosal tissue, 4 bNAbs (PG9, PG16, VRC01, 4E10) were tested in tissue culture models of human colonic and ectocervical tissues. All 4 nAbs reduced HIV transmission, with a relative efficacy of PG16 > PG9 > VRC01 >> 4E10. The nAbs had a good safety profile and were not affected by the presence of semen. Scott2015 (immunotherapy)
PG9: The study's goal was to produce modified SOSIP trimers that would reduce the exposure - and, by inference, the immunogenicity - of non-NAb epitopes such as V3. The binding of several modified SOSIP trimers was compared among 12 neutralizing (PG9, PG16, PGT145, PGT121, PGT126, 2G12, PGT135, VRC01, CH103, CD4, IgG2, PGT151, 35O22) and 3 non-neutralizing antibodies (14e, 19b, b6). The V3 non-NAbs 447-52D, 39F, 14e, and 19b bound less well to all A316W variant trimers compared to wild-type trimers. Mice and rabbits immunized with modified, stabilized SOSIP trimers developed fewer V3 Ab responses than those immunized with native trimers. deTaeye2015 (antibody binding site)
PG9: Deep-sequencing and computational methods were used to identify HCDR3 sequences in HIV-naïve donors that mediated binding and neutralization of HIV by mimicking the bnAb PG9 long HCDR3 region when expressed in the context of the rest of the PG9 antibody sequence. 2 naturally occurring HCDR3 sequences from 2 different donors of 70 studied were predicted to adopt a PG9-like hammerhead conformation and were able to bind and neutralize PG9-susceptible viruses. In addition, computational design was used to mimic the process of maturation by somatic mutation of HCDR3 sequences from the HIV-1–naïve repertoire that were predicted to adopt a PG9-like hammerhead conformation. Two to seven mutations in eight different HCDR3 sequences facilitated neutralization of HIV when grafted on a PG9 Ab background. Willis2016 (antibody lineage)
PG9: HIV-1 strains were isolated from 60 patients infected with CRFs 01_AE, 07_BC, and 08_BC. Eight CRF01 strains that produced high-titer Env pseudoviruses were studied further. All were sensitive to neutralization by VRC01, PG9, PG16, and NIH45-46, but insensitive to 2G12. The PG9 have affinity for epitopes located in the conserved regions of the V2-V3 loop. Binding of PG9 and PG16 with the virus was largely dependent on the same residues, although PG16 was more sensitive to V3 loop substitutions than PG9. Sequence analysis of PG9- and PG16-resistant viruses revealed complex mutation patterns associated with residues that are critical for PG9/PG16 binding. CNAE14 was shown to be resistant to both PG9 and PG16. It is likely that substitutions S158T, S162T, K305T, and I307T jointly contribute to this resistance phenotype. Chen2016 (neutralization, subtype comparisons)
PG9: A large cross-sectional study of sera from 205 ART-naive patients infected with different HIV clades was tested against a panel of 219 cross-clade Env-pseudotyped viruses. Their neutralization was compared to the neutralization of 10 human bNAbs (10E8, 4E10, VRC01, PG9, PGT145, PGT128, 2F5, CH01, b12, 2G12) tested with a panel of 119 Env-pseudotyped viruses. Results from b12 and 2G12 suggested that these bnAbs may not be as broadly neutralizing as previously thought. PG9 neutralized 86% of the 199 viruses tested. Hraber2014 (neutralization)
PG9: The study compared binding and neutralization of 4 V2 apex bnAbs (PG9, CH01, PGT145, and CAP256.VRC26.09). All recognized a core epitope on V1/V2 (the N-linked glycan at N160 and cysteine-linked lysine rich, HXB2:126-196), which includes residue N160 as well as N173. The lysine rich region on strand C of HIV-1 V2 that is key for binding to the nAb contains the sequence (168)KKQK(171). Inferred germline versions of three of the prototype bnAbs were able to neutralize specific Env isolates. Soluble Env derived from one of these isolates was shown to form a well-ordered Env trimer that could serve as an immunogen to initiate a V2-apex bnAb response. Escape from bnAb PG9 was seen in patient Donor_64 by mutations K169T and K171E. 99% amino acid sequence identity exists between PG9 and CAP256.09 in VH-germline gene. Andrabi2015 (antibody binding site, neutralization, vaccine antigen design, escape, antibody lineage)
PG9: Double, triple or quadruple combinations of fifteen bNAbs that target 4 distinct epitope regions: the CD4 binding site (3BNC117, VRC01, VRC07, VRC07-523, VRC13), the V3-glycan supersite (10–1074, 10-1074V, PGT121, PGT128), the V1/V2-glycan site (PG9, PGT145, PGDM1400, CAP256-VRC26.08, CAP256-VRC26.25), and the gp41 MPER epitope (10E8) were studied. Their neutralization potency and breadth were assayed against a panel of 200 acute/early subtype C strains, and compared to a novel, highly accurate predictive mathematical model (no-overlap Bliss Hill model, CombiNaber tool, LANL HIV Immunology database). These data were used to predict the best combinations of bNAbs for immunotherapy. Wagh2016 (neutralization, immunotherapy)
PG9: An atomic-level understanding of V1V2-directed bNAb recognition in a donor was used in the design of V1V2 scaffolds capable of interacting with quaternary-specific V1V2-directed bNAbs. The cocrystal structure of V1V2 with antibody CH03 from a second donor is reported and Env interactions of antibody CAP256-VRC26 from a third donor are modeled. V1V2-directed bNAbs used strand-strand interactions between a protruding Ab loop and a V1V2 strand but differed in their N-glycan recognition. Ontogeny analysis indicated that protruding loops develop early, and glycan interactions mature over time. Combination of the atomic-level information and negative-stain EM of PG9 in complex with a soluble trimeric Env mimic, BG505 SOSIP.664, suggest that the quaternary dependency of PG9 arises from its recognition of glycan N160 from a neighboring protomer24. Gorman2016 (glycosylation, structure, antibody lineage)
PG9: The human Ab gene repertoires of uninfected and HIV-1-infected individuals were studied at genomic DNA (gDNA) and cDNA levels to determine the frequencies of putative germline Ab genes of known HIV-1 bnAbs. All libraries were deep sequenced and analysed using IMGT/HighV-QUEST software (http://imgt.org/HighV-QUEST/index. The human gDNA Ab libraries were more diverse in heavy and light chain V-gene lineage usage than the cDNA libraries. This implied that the human gDNA Ab gene repertoires may have more potential than the cDNA repertoires to develop HIV-1 bnmAbs. Relatively high frequencies of the VH and VKs and VLs that used the same V-genes and had the same CDR3 lengths as known HIV-1 bnmAbs regardless of (D)J-gene usage. Frequencies of the VLs with the identical VJ recombinations to PG9 were relatively high. The putative germline genes were determined for a set of mAbs (b12, VRC01, VRC03, NIH45-46, 3BNC60, PG9, PGT127, and X5). Zhang2013 (antibody lineage, germline)
PG9: Galactosyl ceramide (Galcer), a glycosphingolipid, is a receptor for the HIV-1 Env glycoprotein. This study has mimicked this interaction by using an artificial membrane containing synthetic Galcer and recombinant HIV-1 Env proteins to identify antibodies that would block the HIV-1 Env-Galcer interaction. HIV-1 ALVAC/AIDSVAX vaccinee-derived MAbs specific for the gp120 C1 region blocked Galcer binding of a transmitted/founder HIV-1 Env gp140. The antibody-dependent cellular cytotoxicity-mediating CH38 IgG and its natural IgA isotype were the most potent blocking antibodies. PG9 exhibited moderate Env-Galcer blocking. Dennison2014 (ADCC, antibody binding site, antibody interactions, glycosylation)
PG9: A unified convergent strategy for the rapid production of bi-, tri-, and tetra-antennary complex type N-glycans with and without terminal N-acetylneuraminic acid residues connected via the α-2,6 or α-2,3 linkages is reported which may facilitate the design of carbohydrate-based immunogens. A glycan microarray-based profiling of PG9 was used to understand the binding specificity. No detectable binding for PG9, probably due to (1) very weak binding affinity toward protein/peptide free glycans, (2) the requirement of closely spaced Man5GlcNAc2 (N160) and complex type glycan (N156/163) as PG9 epitopes, and (3) the heterogeneous distribution of NHS groups on glass slides resulting in uneven and low-density glycan arrays. Shivatare2013 (glycosylation, structure)
PG9: The effect of PNGS on viral infectivity and antibody neutralization (2F5, 4E10, b12, VRC01, VRC03, PG9, PG16, 3869) was evaluated through systemic mutations of each PNGS on CRF07_BC strain. Mutations at N197 (C2), N301 (V3), N442 (C4), and N625 (gp41) rendered the virus more susceptible to neutralization by MAbs that recognize the CD4 binding site or gp41. Generally, mutations on V4/V5 loops, C2/C3/C4 regions, and gp41 reduced the neutralization sensitivity to PG16. However, mutation of N289 (C2) made the virus more sensitive to both PG9 and PG16. Mutations at N142 (V1), N355 (C3) and N463 (V5) conferred resistance to neutralization by anti-gp41 MAbs. Available structural information of HIV Env and homology modeling was used to provide a structural basis for the observed biological effects of these mutations. Wang2013 (neutralization, structure)
PG9: Incomplete neutralization may decrease the ability of bnAbs to protect against HIV exposure. In order to determine the extent of non-sigmoidal slopes that plateau at <100% neutralization, a panel of 24 bnMAbs targeting different regions on Env was tested in a quantitative pseudovirus neutralization assay on a panel of 278 viral clones. All bNAbs had some viruses that they neutralized with a plateau <100%, but those targeting the V2 apex and MPER did so more often. All bnMAbs assayed had some viruses for which they had incomplete neutralization and non-sigmoidal neutralization curves. bNAbs were grouped into 3 groups based on their neutralization curves: group 1 antibodies neutralized more than 90% of susceptible viruses to >95% (PGT121-123, PGT125-128, PGT136, PGV04); group 2 was less effective, resulting in neutralization of 60-84% of susceptible viruses to >95% (b12, PGT130-131, PGT135, PGT137, PGT141-143, PGT145, 2G12, PG9); group 3 neutralized only 36-60% of susceptible viruses to >95% (PG16, PGT144, 2F5, 4E10). McCoy2015 (neutralization)
PG9: The neutralization abilities of Abs were enhanced by bioconjugation with aplaviroc, a small-molecule inhibitor of virus entry into host cells. Diazonium hexafluorophosphate was used. The conjugated Abs blocked HIV-1 entry through two mechanisms: by binding to the virus itself and by blocking the CCR5 receptor on host cells. Chemical modification did not significantly alter the potency and the pharmacokinetics. The PG9-aplaviroc conjugate was tested against a panel of 117 HIV-1 strains and was found to neutralize 100% of the viruses. PG9-aplaviroc conjugate IC50s were lower than those of PG9 in neutralization studies of 36 of the 117 HIV-1 strains. Gavrilyuk2013 (neutralization)
PG9: This study investigated the immunogenicity of three ΔV1V2 deleted variants of the HIV-1 Env protein. The mutant ΔV1V2.9.VK induced a prominent response directed to epitopes effectively bound and neutralized the ΔV1V2 Env virus. This Env variant efficiently neutralized tier 1 virus SF162.This did not result in broad neutralization of neutralization-resistant virus isolates. BG505 SOSIP.664 trimers bind very efficiently to quaternary structure dependent, broadly neutralizing PG9 against the V1V2 domain. Bontjer2013 (vaccine antigen design, structure)
PG9: This review surveyed the Vectored Immuno Prophylaxis (VIP) strategy, which involves passive immunization by viral vector-mediated delivery of genes encoding bnAbs for in vivo expression. Recently published studies in humanized mice and macaques were discussed as well as the pros and cons of VIP towards clinical applications to control HIV endemics. Yang2014 (immunoprophylaxis, review, antibody gene transfer)
PG9: The ability of bNAbs to inhibit the HIV cell entry was tested for b12, VRC01,VRC03, PG9, PG16, PGT121, 2F5, 10E8, 2G12. Among them, PGT121, VRC01, and VRC03 potently inhibited HIV entry into CD4+ T cells of infected individuals whose viremia was suppressed by ART. Chun2014 (immunotherapy)
PG9: Pairwise combinations of 6 NAbs (4E10, 2F5, 2G12, b12, PG9, PG16) were tested for neutralization of pseudoviruses and transmitted/founder viruses. Each of the NAbs tested targets a different region of gp120 or gp41. Some pairwise combinations enhanced neutralization synergistically, suggesting that combinations of NAbs may enhance clinical effectiveness. Miglietta2014 (neutralization)
PG9: The infectious virion (iVirions) capture index (IVCI) of different Abs have been determined. bnAbs captured higher proportions of iVirions compared to total virus particles (rVirions) indicating the capacity, breadth and selectively of bnAbs to capture iVirions. IVCI was additive with a mixture of Abs, providing proof of concept for vaccine-induced effect of improved capacity. bnAb PG9 showed significantly high IVCI and captured 100% of CRF01_A/E infectious virions AE.92TH023 and AE.CM244, as well as subtype B MN virus. Liu2014 (binding affinity)
PG9: Study evaluated 4 gp140 Env protein vaccine immunogens derived from an elite neutralizer donor VC10042, an HIV+ African American male from Vanderbilt cohort. Env immunogens, VC10042.05, VC10042.05RM, VC10042.08 and VC10042.ela, elicited high titers of cross-reactive Abs recognizing V1/V2 regions. PG9 exhibited very weak binding with trimeric VC10042.ela and moderate binding with monomeric form of all 4 immunogens. Carbonetti2014 (elite controllers, vaccine-induced immune responses)
PG9: The study compared various factors affecting the accessibility of epitopes for antibodies targeting the V2 integrin (V2i) region, versus the V3 region. CD4 treament of BaL and JRFL pseudoviruses increased their neutralization sensitivity to V3 MAbs, but not to V2i MAbs. Viruses grown in a glycosidase inhibitor were more sensitive to neutralization by V3, but not V2i, MAbs. Increasing the time of virus-MAb interaction increased virus neutralization by some V2i MAbs and all V3 MAbs. The structural dynamics of V2i and V3 epitopes has important effects in neutralization. Some experiments also included V2p antibodies CH58, CH59, and PG9 for comparison. Upadhyay2014 (glycosylation, neutralization)
PG9: A gp140 trimer mosaic construct (MosM) was produced based on M group sequences. MosM bound to CD4 as well as multiple bNAbs, including VRC01, 3BNC117, PGT121, PGT126, PGT145, PG9 and PG16. The immunogenicity of this construct, both alone and mixed together with a clade C Env protein vaccine, suggest a promising approach for improving NAb responses. Nkolola2014 (vaccine antigen design)
PG9: Cross-group neutralization of HIV-1 isolates from groups M, N, O, and P was tested with diverse patient sera and bNAbs PG9, PG16, 4E10, b12, 2F5, 2G12, VRC01, VRC03, and HJ16. The primary isolates displayed a wide spectrum of sensitivity to neutralization by the human sera, with some cross-group neutralization clearly observed. Among the bNAbs, only PG9 and PG16 showed any cross-group neutralization. The group N prototype strain YBF30 was highly sensitive to neutralization by PG9, and the interaction between their key residues was confirmed by molecular modeling. The conservation of the PG9/PG16 epitope within groups M and N suggests its relevance as a vaccine immunogen. Braibant2013 (neutralization, variant cross-reactivity)
PG9: The V2 region where PG9, an anti-V1V2 bNAb binds exists as a beta-strand. Haynes2013 (review)
PG9: PG9 was one of 10 MAbs used to study chronic vs. consensus vs. transmitted/founder (T/F) gp41 Envs for immunogenicity. Consensus Envs were the most potent eliciters of response but could only neutralize tier 1 and some tier 2 viruses. T/F Envs elicited the greatest breadth of NAb response; and chronic Envs elicited the lowest level and narrowest response. This V1V2 conformational loop binding Nab bound well at <10 nM to 3/5 chronic Envs, 2/6 Consensus Envs and 2/7 T/F Envs. Liao2013c (antibody interactions, binding affinity)
PG9: Design, synthesis and antigenic evaluation of novel cyclic V1V2 glycopeptides carrying defined N-linked glycans, N160 and N156/N173 has been reported in terms of PG9 and PG16 binding and neutralization. A Man₅GlcNAc₂ glycan at N160 and a sialyted N-glycan are crtical for antigen binding. Amin2013 (glycosylation)
PG9: Binding properties of a synthesized V1V2 glycopeptide immunogen that selectively targets bnAbs' naive B cells is reported. The unmutated common ancestor (UCA) of PG9 showed nanomolar affinity to V1V2 bearing Man₅GlcNAc₂ glycan units. Binding of PG9 was undetectable however in the absence of the V2 backbone peptide suggesting a very weak binding affinity to oligomannose glycan alone. Disulfide-linked dimer formation was also required for PG9 binding to V1V2. Alam2013
PG9: PG9 in combination with NAbs NH45-46m2 and NIH46-42m7 was able to control viremia as well as to reduce routes to escape of YU-2 HIV-1. Diskin2013
PG9: This study showed that the inability of Env to elicit the production of broadly neutralizing Abs is due to the inability of diverse Env to engage the germ line B cell receptor forms of known bNAbs. PG9 showed binding to 61% of the recombinant Envs tested including 7 out of 17 clade B Envs, 11 of 16 clade C Envs, 6 of 7 clade A Envs and the gp120 form of A/E A244 Env. The predicted germ line version of PG9 did not exhibit any detectable binding against these Envs. Ca²⁺ influx through the PG9 BCR was also tested as a function of binding affinity. McGuire2014 (antibody interactions, antibody lineage)
PG9: The neutralization profile of 1F7, a human CD4bs mAb, is reported and compared to other bnNAbs. 1F7 exhibited extreme potency against primary HIV-1, but limited breadth across clades. PG9 neutralized 83% of a cross-clade panel of 157 HIV-1 isolates (Fig. S1) while 1F7 neutralized only 20% of the isolates. Gach2013 (neutralization)
PG9: This study reports the development of a new cell-line (A3R5)-based highly sensitive Ab detection assay. This T-lymphoblastoid cell-line stably expreses CCR5 and recognizes CCR5-tropic circulating strains of HIV-1. A3R5 cells showed greater neutralization potency compared to the current cell-line of choice TZM-bl. PG9 was used as a reference Ab in neutralization assay comparing A3R5 and TZM-bl. McLinden2013 (assay or method development)
PG9: A highly conserved mechanism of exposure of ADCC epitopes on Env is reported, showing that binding of Env and CD4 within the same HIV-1 infected cell effectively exposes these epitopes. The mechanism might explain the evolutionary advantage of downregulation of cell surface CD4v by the Vpu and Nef proteins. PG9 was used in CD4 coexpression and competitive binding assay. Veillette2014 (ADCC)
PG9: Clade A Env sequence, BG505, was identified to bind to bNAbs representative of most of the known NAb classes. This sequence is the best natural sequence match (73%) to the MRCA sequence from 19 Env sequences derived from PG9 and PG16 MAbs' donor. A point mutation at position L111A of BG505 enabled more efficient production of a stable gp120 monomer, preserving the major neutralization epitopes. The antisera produced by this adjuvanted formulation of gp120 competed with bnAbs from 3 classes of non-overlapping epitopes. PG9 showed very high neutralization titer against BG505 pseudovirus in a competitive binding assay as shown in Table 1. Env sequence from PG9 donor showed potential N glycosylation (PNG) sites at position 160 and 156, suggesting that a substitution at one of these sites is not the primary cause of neutralization resistance to PG9 (Table 4). This emphasizes that the BG505 L111Agp120 immunogen can elicit a robust Ab response to PG9. Hoffenberg2013 (antibody interactions, glycosylation, neutralization)
PG9: High affinity binding of PG9 with a soluble SOSIP.664 gp140 trimer constructed from the Clade A BG505 sequence was demonstrated. This enabled structural and biophysical characterization of the PG9:Env trimer complex. Electron microscopy (EM) and other assays indicate that only a single PG9-Fab binds to the Env trimer. EM reconstruction also demonstrated that PG9 recognized the trimer asymmetrically at its apex via contact with 2 of the 3 gp120 protomers. In addition to N156 and N160 glycan interactions with a scaffolded V1/V2 domain, PG9 also makes secondary interactions with an N160 glycan from an adjacent gp120 protomer in the Ab-trimer complex. A glycan mutation to PG9 caused a >10fold reduction of Fab affinity for the BG505 SOSIP.664 gp 140 trimer reflecting adverse effects on trimer binding and virus neutralization. PG9 recognized glycosylated Env proteins with much higher affinity compared to non-glycosylated ones. Julien2013 (antibody interactions, glycosylation, structure)
PG9: To focus immune responses to sites of NAb vulnerability while avoiding immune-evasion by the rest of Env, MPER, V1/V2, and V3 glycan sites were transplanted onto algorithm-identified acceptor scaffolds (proteins with a backbone geometry that recapitulates the antigenicity of the transplanted site). The V1/V2-transplant was not successful in eliciting a robust PG9 response. Zhou2014 (vaccine antigen design)
PG9: This is a review of identified bNAbs, including the ontogeny of B cells that give rise to these antibodies. Breadth and magnitude of neutralization, unique features and similar bNAbs are listed. PG9 is a V1/V2-directed Ab, with breadth 70%, IC₅₀ 0.31 μg per ml, and its unique feature is its extended CDR H3, which is often tyrosine-sulfated. Similar MAbs include PG16 and CH01-04. Kwong2013 (review)
PG9: 8 bNAbs (PGT151 family) were isolated from an elite neutralizer. The new bNAbs bind a previously unknown glycan-dependent epitope on the prefusion conformation of gp41. These MAbs are specific for the cleaved Env trimer and do not recognize uncleaved Env trimer. PGT151 family Abs showed 1 log higher neutralization potency than PG9. Falkowska2014
PG9: A statistical model selection method was used to identify a global panel of 12 reference Env clones among 219 Env-pseudotyped viruses that represent the spectrum of neutralizing activity seen with sera from 205 chronically HIV-1-infected individuals. This small final panel was also highly sensitive for detection of many of the known bNAbs, including this one. The small panel of 12 Env clones should facilitate assessments of vacine-elicited NAbs. Decamp2014 (assay or method development)
PG9: The conserved central region of gp120 V2 contains sulfated tyrosines (Tys173 and Tys177) that in the CD4-unbound prefusion state mediate intramolecular interaction between V2 and the conserved base of the third variable loop (V3), functionally mimicking sulfated tyrosines in CCR5 and anti-coreceptor-binding-site antibodies such as 412d. Enhancement of tyrosine sulfation decreased binding and neutralization of HIV-1 BaL by monomeric sCD4, 412d, and anti-V3 antibodies and increased recognition by the trimer-preferring antibodies PG9, PG16, CH01, and PGT145. Conversely, inhibition of tyrosine sulfation increased sensitivity to soluble CD4, 412d, and anti-V3 antibodies and diminished recognition by trimer-preferring antibodies. These results identify the sulfotyrosine-mediated V2-V3 interaction as a critical constraint that stabilizes the native HIV-1 envelope trimer and modulates its sensitivity to neutralization. Cimbro2014
PG9:X-ray crystallography, surface plasmon resonance and pseudovirus neutralization were used to characterize a heavy chain only llama antibody, named JM4. The full-length IgG2b version of JM4 neutralizes over 95% of circulating HIV-1 isolates. JM4 targets a hybrid epitope on gp120 that combines elements from both the CD4 binding region and the coreceptor binding surface. JM4 IgG2b was able to potently neutralize the HIV-1 isolates that were resistant to PG9. Acharya2013 (neutralization)
PG9: 12 somatically related nAbs were isolated from donor CAP256. All nAbs of CAP256-VRC26 lineage had long CDRH3 regions necessary to penetrate the glycan shield and engage the V1V2 epitope. Both CAP256-VRC26 Abs and PG9 class nAbs showed similarity in recognizing the trimeric V1V2 cap. Unlike PG9, the CAP256-VRC26 Abs were only partially and variably sensitive to loss of glycans at N160 and N156. Doria-Rose2014 (glycosylation)
PG9: This is a review of a satellite symposium at the AIDS Vaccine 2012 conference, focusing on antibody gene transfer. Phil Johnson presented results comparing an immunoadhesin form of the antibody PG9 with the native IgG architecture in which he found that the native IgG architecture had a neutralization potency tenfold greater than that of the immunoadhesin, suggesting that natural antibody architectures are more preferable for further clinical development. Balazs2013 (immunoprophylaxis)
PG9: A computational method to predict Ab epitopes at the residue level, based on structure and neutralization panels of diverse viral strains has been described. This method was evaluated using 19 Env-Abs, including PG9, against 181 diverse HIV-1 strains with available Ab-Ag complex structures. Chuang2013 (computational epitope prediction)
PG9: This study reports the glycan binding specificities and atomic level details of PG16 epitope and somatic mechanisms of clonal antibody diversification. Three PG16 specific residues Arg94_LC,Ser95_LC and His95_LC (RSH) are found to be critical for sialic acid binding on complex glycan. RSH residues were introduced into PG9 to produce a chimeric antibody with enhanced neutralization. The co-crystal structure of PG9 bound to V1-V2 is discussed and compared to PG16 and PG9-PG16-RSH chimeric Ab based on its ability to recognize a combination of N-linked glycans and envelop polypeptide. Pancera2013 (antibody binding site, glycosylation, structure, chimeric antibody)
PG9: Four V2 MAbs CH58, CH59, HG107 and HG120 were isolated from RV144 Thai HIV-1 vaccinees. These MAbs recognized residue 169, neutralized laboratory HIV-1 (tier 1 strains) and mediated ADCC. PG9 was used in the study as a V1-V2 bnAb control to study the binding of the new mAb isolates. While PG9, PG16 and CH01 binding was abrogated by N160K and N156Q mutations and also by native glycosylation, the binding of CH58 and CH59 was not affected. Crystal structures revealed that CH58, CH59, and PG9 recognize overlapping V2 epitopes in dramatically different conformations, ranging from helical to beta strands. Liao2013b (ADCC, structure)
PG9: The complexity of the epitopes recognized by ADCC responses in HIV-1 infected individuals and candidate vaccine recipients is discussed in this review. PG9 is discussed as the V2 region-targeting, anti-gp120 BNAb exhibiting ADCC activity and having a discontinuous epitope. RV144 vaccine induced mAbs CH58 and CH59 also bind to the same region of PG9, but do not display preferential binding to gp120 and don't bind to glycans in position 156 and 160. Pollara2013 (ADCC, review)
PG9: "Neutralization fingerprints" for 30 neutralizing antibodies were determined using a panel of 34 diverse HIV-1 strains. 10 antibody clusters were defined: VRC01-like, PG9-like, PGT128-like, 2F5-like, 10E8-like and separate clusters for b12, CD4, 2G12, HJ16, 8ANC195. Georgiev2013 (neutralization)
PG9: ADCC mediated by CD4i mAbs (or anti-CD4i-epitope mAbs) was studied using a panel of 41 novel mAbs. Three epitope clusters were classified, depending on cross-blocking in ELISA by different mAbs: Cluster A - in the gp120 face, cross-blocking by mAbs A32 and/or C11; Cluster B - in the region proximal to CoRBS (co-receptor binding site) involving V1V2 domain, cross-blocking by E51-M9; Cluster C - CoRBS, cross-blocking by 17b and/or 19e. The ADCC half-maximal effective concentrations of the Cluster A and B mAbs were generally 0.5^-1 log lower than those of the Cluster C mAbs, and none of the Cluster A or B mAbs could neutralize HIV-1. Cluster A's A32- and C11-blockable mAbs were suggested to recognize conformational epitopes within the inner domain of gp120 that involve the C1 region. Neutralization potency and breadth were also assessed for these mAbs. No correlation was found between ADCC and neutralization Abs' action or functional responses. Guan2013 (ADCC, antibody interactions)
PG9: This study describes an ˜11 Angstrom cryo-EM structure of the trimeric HIV-1 Env precursor in its unliganded state. The three gp120 and gp41 subunits form a cage like structure with an interior void surrounding the trimer axis which restricts Ab access. crystal structure of PG9 was referred in the context of gp120 V1/V2 binding domains. Mao2012 (structure)
PG9: Emergence and evolution of the earliest cross-reactive neutralizing antibody responses were studied in B clade-infected individual, Two distinct epitopes on Env were targeted. First specificity appeared at 3 years post infection and targeted the CD4-binding site. Second specificity appeared a year later. It was due to PG9-like antibodies, which were able to neutralize those viruses not susceptible to the anti-CD4-BS antibodies in AC053. Mikell2012 (neutralization, rate of progression, polyclonal antibodies)
PG9: Neutralization profiles of 7 bnAbs were analyzed against 45 Envs (A, C, D clades), obtained soon after infection (median 59 days). The transmitted variants have distinct characteristics compared to variants from chronic patients, such as shorter variable loops and fewer potential N-linked glycosylation sites (PNGS). PG9 neutralized 49% of these viruses. Goo2012 (neutralization, rate of progression)
PG9: A computational tool (Antibody Database) identifying Env residues affecting antibody activity was developed. As input, the tool incorporates antibody neutralization data from large published pseudovirus panels, corresponding viral sequence data and available structural information. The model consists of a set of rules that provide an estimated IC₅₀ based on Env sequence data, and important residues are found by minimizing the difference between logarithms of actual and estimated IC₅₀. The program was validated by analysis of MAb 8ANC195, which had unknown specificity. Predicted critical N-glycosylation for 8ANC195 were confirmed in vitro and in humanized mice. The key associated residues for each MAb are summarized in the Table 1 of the paper and also in the Neutralizing Antibody Contexts & Features tool at Los Alamos Immunology Database. West2013 (glycosylation, computational epitope prediction)
PG9: Identification of broadly neutralizing antibodies, their epitopes on the HIV-1 spike, the molecular basis for their remarkable breadth, and the B cell ontogenies of their generation and maturation are reviewed. Ontogeny and structure-based classification is presented, based on MAb binding site, type (structural mode of recognition), class (related ontogenies in separate donors) and family (clonal lineage). This MAb's classification: gp120 V1V2 site, penetrating CDR H3 binds two glycans and strand, PG9 class, PG9 family. Kwong2012 (review, structure, broad neutralizer)
PG9: This review discusses the new research developments in bnAbs for HIV-1, Influenza, HCV. Models of the HIV-1 Env spike and of Influenza visrus spike with select bnAbs bound are shown. Burton2012 (review)
PG9: This review discusses how analysis of infection and vaccine candidate-induced antibodies and their genes may guide vaccine design. This MAb is listed as V1/V2 conformational epitope bnAb, isolated after 2009 by neutralization screening of cultured, unselected IgG+ memory B cells. Bonsignori2012b (vaccine antigen design, vaccine-induced immune responses, review)
PG9: Antigenic properties of 2 biochemically stable and homogeneous gp140 trimers (A clade 92UG037 and C clade CZA97012) were compared with the corresponding gp120 monomers derived from the same percursor sequences. The trimers had nearly all the antigenic properties expected for native viral spikes and were markedly different from monomeric gp120. Both trimers, but not monomers, bound to PG9 and PG16. Kovacs2012 (antibody binding site, neutralization, binding affinity)
PG9: Glycan shield of HIV Env protein helps to escape the Ab recognition. Several of the PGT BnAbs interact directly with the HIV glycan coat. Crystal structures of Fabs PGT127 and PGT128 showed that the high neutralizing potency was mediated by cross-linking Env trimers on the viral surface. PGT128 was compared and referred as an order of magnitude more potent than PG9. Pejchal2011 (glycosylation, structure, broad neutralizer)
PG9: PG9 and PG9-like V1V2-directed MAbs, that require an N-linked glycan at Env 160, were analyzed for gain-of-function mutations. 21 PG9-resistant HIV-1 isolates were analyzed by mutagenesis and neutralization assays. E to K mutations at positions 168, 169, 171 led to the most dramatic improvements on sensitivity to these MAbs (PG9, PG16, CH01, CH04, PGT141, PGT145). Doria-RoseNA2012 (escape)
PG9: The study used the swarm of quasispecies representing Env protein variants to identify mutants conferring sensitivity and resistance to BnAbs. Libraries of Env proteins were cloned and in vitro mutagenesis was used to identify the specific AA responsible for altered neutralization/resistance, which appeared to be associated with conformational changes and exposed epitopes in different regions of gp160. The result showed that sequences in gp41, the CD4bs, and V2 domain act as global regulator of neutralization sensitivity. PG9 was used as BnAb to screen Env clones. wtR clone was weakly sensitive to PG9. ORourke2012 (neutralization)
PG9: Glycan Asn332-targeting broadly cross-neutralizing (BCN) antibodies were studied in 2 C-clade infected women. The ASn332 glycan was absent on infecting virus, but the BCN epitope with Asn332 evolved within 6 months though immune escape from earlier antibodies. Plasma from the subject CAP177 neutralized 88% of a large multi-subtype panel of 225 heterologous viruses, whereas CAP 314 neutralized 46% of 41 heterologous viruses but failed to neutralize viruses that lack glycan at 332. PG9 was referred to have second BCN Ab epitopes at AA 156 and 160 in addition to 332. Moore2012 (neutralization, escape)
PG9: Crystal structures of unliganded core gp120 from HIV-1 clade B, C, and E were determined to understand the mechanism of CD4 binding capacity of unliganded HIV-1. The results suggest that the CD4 bound conformation represents "a ground state" for the gp120 core with variable loop. PG9 was used as a control to prove whether the purified and crystallized gp120 is in the CD4 bound conformational state or not. Kwon2012 (structure)
PG9: Vaccination efficacy of RV144 is described. The authors proposed that RV144 induced antibodies against Env V1/V2. The relationship between vaccine status and V1/V2 sequence have been characterized. The estimated cumulative HIV-1 incidence curve in the vaccine and placebo groups showed immunogenicity for K169 and 1181X genotypes and no immunogenicity for the opposite residues. PG9 was discussed as the quaternary-structure-preferring (QSP) antibody and mutations at positions 169 and 181 were associated with significant alteration in neutralization. Rolland2012 (vaccine-induced immune responses)
PG9: The use of computationally derived B cell clonal lineages as templates for HIV-1 immunogen design is discussed. PG9 has been discussed in terms of immunogenic and functional characteristics of representative HIV-1 BnAbs and their reactions to antigens. Haynes2012 (antibody interactions, memory cells, vaccine antigen design, review, antibody polyreactivity, broad neutralizer)
PG9: Polyclonal B cell responses to conserved neutralization epitopes are reported. Cross-reactive plasma samples were identified and evaluated from 308 subjects tested. PG9 was used as a control mAb in the comprehensive set of assays performed. C1-0763 targeted a region similar to PG9 and PG16 recognizing a V1/V2 loop dependent epitope. Tomaras2011 (neutralization, polyclonal antibodies)
PG9: Several antibodies including 10-1074 were isolated from B-cell clone encoding PGT121, from a clade A-infected African donor using YU-2 gp140 trimers as bait. These antibodies were segregated into PGT121-like (PGT121-123 and 9 members) and 10-1074-like (20 members) groups distinguished by sequence, binding affinity, carbohydrate recognition, neutralizing activity, the V3 loop binding and the role of glycans in epitope formation. PG9 was used as a control. Detail information on the binding and neutralization assays are described in the figures S2-S11. Mouquet2012a (glycosylation, neutralization, binding affinity)
PG9: YU2 gp140 bait was used to characterize 189 new MAbs representing 51 independent IgG memory B cell clones from 3 clade A or B HIV infected patients exhibiting broad neutralizing activity. PG9 was referred to in discussing the efficiency of YU-2 gp140 trimer as a bait for Ab capture. Mouquet2011 (neutralization)
PG9: The rational design of vaccines to elicit broadly neutralizing antibodies to HIV-1 is discussed in relation to understanding of vaccine recognition sites, the structural basis of interaction with HIV-1 env and vaccine developmental pathways. Role of PG9 has been discussed in terms of humoral immune response during HIV1 infection. The vulnerability sites on the viral spike shows quaternary structural constraints, and maps to the second and third variable regions of gp120 (variable loops V2 and V3). PG9 recognizes these regions and neutralizes 70%–80% of current circulating isolates. Kwong2011 (antibody binding site, neutralization, vaccine antigen design, review)
PG9: A panel of glycan deletion mutants was created by point mutation into HIV gp160, showing that glycans are important targets on HIV-1 glycoproteins for broad neutralizing responses in vivo. Enrichment of high mannose N-linked glycan(HM-glycan) of HIV-1 glycoprotein enhanced neutralizing activity of sera from 8/9 patients. PG9 was used as a control to compare the neutralizing activity of patients' sera. Lavine2012 (neutralization)
PG9: Ab-driven escape and Ab role in infection control and prevention are reviewed. Main focus is on NAbs, but Ab acting through effector mechanisms are also discussed. PG9 is discussed in the context of developing broadly cross-neutralizing antibodies. Overbaugh2012 (escape, review)
PG9: Neutralization activity was compared against MAb 10E8 and other broad and potent neutralizers in a 181-isolate Env-pseudovirus panel. PG9 neutralized 78% of viruses at IC50<50 μg/ml and 65% of viruses at IC50<1 μg/ml, compared with 98% and 72% of MAb 10E8, respectively. Huang2012a (neutralization)
PG9: Antigenic properties of undigested VLPs and endo H-digested WT trimer VLPs were compared. Binding to E168K+ N189A WT VLPs was dramatic compared to the parent WT VLPs, uncleaved VLPs. There was no significant correlation between E168K+N189A WT VLP binding and PG9 neutralization, while trimer VLP ELISA binding and neutralization exhibited a significant correlation. BN-PAGE shifts using digested E168K + N189A WT trimer VLPs exhibited prominence compared to WT VLPs. Tong2012 (neutralization, binding affinity)
PG9: Broadly neutralizing antibodies circulating in plasma were studied by affinity chromatography and isoelectric focusing. The Abs fell in 2 groups. One group consisted of antibodies with restricted neutralization breadth that had neutral isoelectric points. These Abs bound to envelope monomers and trimers versus core antigens from which variable loops and other domains have been deleted. Another minor group consisted of broadly neutralizing antibodies consistently distinguished by more basic isoelectric points and specificity for epitopes shared by monomeric gp120, gp120 core, or CD4-induced structures. The pI values estimated for neutralizing plasma IgGs were compared to those of human anti-gp120 MAbs, including 5 bnMAbs (PG9, PG16, VRC01, b12, and 2G12), 2 narrowly neutralizing MAbs (17b and E51), and 3 nonneutralizing MAbs (A32, C11, and 19e). bnMAbs PG9 and PG16 exhibited more-neutral pIs (around 7.8), matching the more-neutral end of the plasma-derived fraction series, showing broadly neutralizing, but not most potent activity. Sajadi2012 (polyclonal antibodies)
PG9: Sensitivity to neutralization was studied in 107 full-length Env molecular clones from multiple risk groups in various locations in China. Neutralization sensitivity to plasma pools and bNAbs was not correlated. PG9 neutralized 81% (25/31) and PG16 neutralized 71% (22/31) of the viruses tested. Viruses insensitive to PG9 were all equally insensitive to PG16 but not the other way around, suggesting that PG9 can tolerate more viral glycoprotein amino acid substitutions than PG16. Shang2011 (glycosylation, neutralization, subtype comparisons)
PG9: The sensitivity to PG9 and PG16 of pseudotyped viruses was analysed carrying envelope glycoproteins from the viral quasispecies of three HIV-1 clade CRF01_AE-infected patients. It was confirmed that an acidic residue or a basic residue at position 168 in the V2 loop is a key element determining the sensitivity to PG9 and PG16. In addition, evidence is provided of the involvement of a conserved residue at position 215 of the C2 region in the PG9/PG16 epitopes. Sensitivity to PG9 in 10 Env-pseudotyped viruses was analyzed. Five clones from case 0377 presented a broad and continuous range of sensitivity to PG9. A broader range of sensitivity was observed in case 0978, clone 0978-M3 being resistant to PG9 whereas two other clones, 0978-M1 and 0978-M2, were highly sensitive. Similarly, two clones from case 0858 displayed peculiar patterns of neutralization: clone 0858-M1 was sensitive to neutralization by PG9 only whereas clone 0858-M2 was resistant to PG9. These results showed the broad heterogeneity in sensitivity to PG9 of closely genetically related envelope glycoproteins derived from single viral quasispecies. Clone 0978-M3 from case 0978 was resistant to PG9, whereas clones 0978-M1/M2 were highly sensitive to PG9. 0978-M3 E168K resulted in a high sensitivity to PG9. In contrast, 0978-M2 K168E conferred resistance to PG9. 0858-M2 M215I conferred sensitivity to PG9, whereas the mutant 0858-M2 M475I remained highly resistant to PG9. I215M diminished the sensitivity of all clones to PG9, except that of clone 5008CL2 for PG9. Thenin2012a (neutralization)
PG9: The interaction of CD4bs-binding MAbs (VRC01, VRC-PG04) and V1V2 glycan-dependent MAbs (PG9, PG16) was analyzed. MAb binding and neutralization studies showed that these two Env targets to not cross-compete and that their combination can mediate additive neutralization. The combination of MAbs VRC01 and PG9 provides a predicted coverage of 97% of 208 isolates at IC50 < 50 μg/ml and of 91% at IC50 < 50 μg/ml. In contrast, the combination of PG9 and PG16 (or the combination of VRC01 and VRC-PG04) was only marginally better than either MAb alone. Doria-Rose2012 (antibody interactions)
PG9: The study showed that alteration between a rare lysine K and a common N-linked glycan at position 160 of HIV-1 gp120 is primarily responsible for toggling between 2909 and PG16/PG9 neutralization sensitivity. These neutralization profiles were mutually exclusive (160K for MAb 2909, 160N for PG16/PG9); there was no case of a virus that was sensitive to both 2909 and PG16/PG9 neutralization. Several more positions were studied: both the PG and 2909 MAbs do not require an asparagine at position 156 for neutralization, both the PG and 2909 antibodies tolerate amino acid variation at position 165, and neither the PG nor the 2909 MAb could tolerate a glutamic acid at position 168. Wu2011a (antibody binding site, escape)
PG9:The reason for natural resistance of a patient Env obtained from plasma of a slow progressing Indian patient to PG9/PG16 MAbs in sharp contrast to its contemporaneous autologous Envs was investigated. Based on the experiments conducted for neutralization and glycosylation, it is suggested that the overall neutralization sensitivity of an Env is the outcome of characteristic molecular features of the V2 loop and neutralization by PG9/16 is balanced by the glycans, net positive charge in β sheet C region of the V2 loop against PG9/16 and possibly the length of the V2 loop. Ringe2012 (glycosylation, neutralization)
PG9: The neutralization activities of IA versus IgG and Fab versions of three broadly neutralizing antibodies: PG9, PG16, and VRC01 was compared to more fully understand the potential trade-offs in vector and construct design. The potential to combine VCR01 and PG9/PG16 activities to produce a single reagent with two gp120 specificities was also explored. In an Env-pseudotyped HIV-1 neutralization assay against a panel of 30 strains, PG9 neutralized 22 strains in IgG form, 18 stains in Fab form, 20 strains in IA form and 10 strains in scFv form. It was found that the PG9, PG16, and VRC01 IAs were severalfold less potent than their IgG forms. West2012 (neutralization)
PG9: The biological properties of 17 Env-pseudotyped viruses derived from variants of mother–infant pairs infected by HIV-1 strains of the CRF01_AE clade were compared, in order to explore their association with the restrictive transmission of the virus. Maternal clones issued from MIPs (mother-infant pairs) 0377, 0978 and 1021 displayed a broad and continuous range of sensitivity to both PG9 and PG16 whereas all infant clones were highly sensitive to both mAbs PG9 and PG16. When the four MIPs were considered in aggregate, infant clones were significantly more sensitive to PG9 and PG16 compared to maternal clones. Thenin2012 (neutralization, mother-to-infant transmission)
PG9: gp120 was cyclically permuted and new N- and C-termini were created within the V1, V3, and V4 loop regions to reduce the length of the linker joining gp120 and M9. Addition of trimerization domains at the V1 loop of cyclic permutants of gp120 resulted in the formation of predominantly trimeric species, which bound CD4 and neutralizing antibodies b12, PG9, and PG16 with higher affinity. Saha2012 (binding affinity)
PG9: The role of envelope expression context and producer cell type was characterized for nine novel replication-competent chimeric HIV-1 isolates from the dominant circulating HIV-1 subtypes in Africa, where most new HIV-1 infections are occurring. Pseudoviruses generated in 293T cells were the most sensitive to antibody neutralization. There was no difference in the neutralization sensitivity of PBMC versus 293T-derived viruses using the MAb PG9. Provine2012 (neutralization)
PG9: Phenotypic activities of a single transmitted/founder (T/F) virus from 24 acute individuals were compared to that of 17 viruses from chronics. There was a trend towards enhanced sensitivity to neutralization by PG9 of T/F Envs compared to chronic Envs. Wilen2011 (neutralization)
PG9: HIV-1 adaptation to neutralization by MAbs VRC01, PG9, PG16 was studied using HIV-1 variants from historic (1985-1989) and contemporary (2003-2006) seroconverters. PG9 neutralized 52% of contemporary viruses at IC50 < 1 μ g/ml. The median IC50s of PG9 for viruses from historical and contemporary seroconverters were not significantly different. There was no clear correlation between the sensitivity to PG9 and presence or absence of certain amino acids, but more mutations were observed in viruses from contemporary seroconverters than from historical ones, and the absence of a potential N-linked glycosylation site at position 160 of V2 coincided with resistance to PG9. Euler2011 (glycosylation, neutralization, escape)
PG9: Using U87 target cells, PGV04 neutralized 88% of 162 viruses, with IC50<50 μm/mg, with U87 target cells compared to 75% neutralized by PG9. The potency of neutralization was comparable. On the 97-virus panel, using TZM-bl target cells, the breadth of neutralization was similar, but PGV04 had increased potency. The neutralization potency of PG9, PG16, VRC01 and PGV04 was approximately 10-fold greater than that of MAbs b12, 2G12, 2F5 and 4E10. Alanine substitutions D279A, I420A and I423A abrogated PGV04 neutralization, but varied in their effects on VRC01, CD4-IgG and b12. Falkowska2012 (neutralization, broad neutralizer)
PG9: Neutralizing antibody repertoires of 4 HIV-infected donors with remarkably broad and potent neutralizing responses were probed. 17 new monoclonal antibodies that neutralize broadly across clades were rescued. All MAbs exhibited broad cross-clade neutralizing activity, but several showed exceptional potency. Although PG9 neutralized 77% of 162 isolates at IC50<50 μg/ml, it was almost 10-fold less potent than several new antibodies PGT 121-123 and 125-128, for which the median antibody concentration required to inhibit HIV activity by 50% or 90% (IC50 and IC90 values) was almost 10-fold lower than that of PG9, VRC01 and PGV04. Walker2011 (neutralization, broad neutralizer)
PG9: Atomic-level structure of V1/V2 in complex with PG9 is reported. Instead of being confounded by the N-linked glycan that shields most of gp120 from immune recognition, PG9 uses N-linked glycan for binding through a mechanism shared by a number of antibodies capable of effective HIV neutralization. The structure shows that the antibody recognizes glycopeptide conjugates and avoids diversity in V1/V2 by making sequence-independent interactions, such as hydrogen bonds. The structure of PG9 is consistent with published mutational data: some residues such as Phe 176 are critical because they form part of the hydrophobic core on the concave face of the V1/V2 sheet. Others form direct contacts: for example, the tyrosine sulphate at residue 100H of PG9 interacts with residue 168 when it is an Arg (strain ZM109) or Lys (strain CAP45), but would be repelled by a Glu (as in strain JR-FL); JR-FL is resistant to neutralization by PG9, but becomes sensitive if Glu 168 is changed to Lys10. V1/V2–PG9 interaction observed in the scaffolded V1/V2–PG9 crystal structures encompasses much of the PG9/PG16 epitope, and the structural integrity of this epitope is sensitive to appropriate assembly of the viral spike. With both CAP45 and ZM109 strains of gp120, the V1/V2 site recognized by PG9 consists primarily of two glycans and a strand. Minor interaction with strand B and with the B–C connecting loop complete the epitope, with the entire PG9-recognized surface of V1/V2 contained within the B–C hairpin. McLellan2011 (antibody binding site, structure)
PG9: CDR H3 domains derived from 4 anti-HIV mAbs, PG16, PG9, b12, E51, and anti-influenza MAb AVF were genetically linked to glycosil-phosphatidylinositol (GPI) attachment signal of decay-accelerating factor (DAF) to determine whether the exceptionally long and unique structure of the CDR H3 subdomain of PG16 is sufficient for epitope recognition and neutralization. Similar degrees of cell surface expression of CDR H3(PG9)/hinge/His tag/DAFs (GPI-CDR H3(PG9)) was observed compared with those of the other GPI-CDR H3 constructs (PG16, AVF, and E51). GPI-CDR H3(PG9) exhibited the same degree of inhibition against 5 representative HIV-1 pseudotypes as that of GPI-CDR H3(PG16 and E51). Liu2011 (neutralization, variant cross-reactivity, structure)
PG9: One Env clone (4–2.J45) obtained from a recently infected Indian patient (NARI-IVC4) had exceptional neutralization sensitivity compared to other Envs obtained at the same time point from the same patient. 4–2.J45 Env expressing M424 showed relative resistance to PG9 over 4–2.J45 expressing I424, wherein comparable sensitivities were found of other Envs to PG9 except YU2, which showed approximately 8 fold increase in neutralization sensitivity to PG9. The indistinctness in PG9/PG16 sensitivities of 4–2.J45 and YU2 Envs expressing M424 was possibly due to some compensatory and conformational changes elsewhere within Env. Ringe2011 (neutralization)
PG9: Several soluble gp140 Env proteins recognized by PG9 and PG16 were identified, and the effect of Env trimerization, the requirement for specific amino acids at position 160 within the V2 loop, and the importance of proper gp120-gp41 cleavage for MAb binding to soluble gp140s were investigated along with whether and how the kinetics of PG9 and PG16 binding to soluble gp140 correlates with the neutralizing potencies of these MAbs. It is reported that the presence of the extracellular part of gp41 on certain gp140 constructs improves the recognition of the PG9 epitope on the gp120 subunit and the trimerization of soluble gp140 may lead to the partial occlusion of the PG9 epitope. PG9 most efficiently recognized modified SF162 Env, SF162K160N of the small number of soluble gp140 Envs tested. The absence of SF162 neutralization by PG9 is the presence of a lysine at position 160 instead of an asparagine. PG16 recognized a smaller number of gp140s tested here than PG9. It is suggested that any structural differences between the virion-associated Env form and the soluble gp140 form have a greater impact on the PG16 epitope than on the PG9 epitope. Davenport2011 (antibody binding site, neutralization, binding affinity, structure)
PG9: The characteristics of HIV-1-specific NAbs were evaluated in 100 breast-fed infants of HIV-1-positive mothers who were HIV-1 negative at birth and they were monitored until age 2. A panel of eight viruses that included variants representative of those in the study region as well as more diverse strains was used to determine the breadth of the infant NAbs. PG9 had low neutralization potency for 2 (QD435.100 M.ENV.A4 and THRO4156.18) out of 8 pseudoviruses in the panel but high for the rest of them. For maternal variants, PG9 had low neutralization potency for 3 (MF535.B1, MJ613.A2 and MK184.E4) out of 12 variants and high for the rest of them. Lynch2011 (neutralization, variant cross-reactivity, mother-to-infant transmission)
PG9: CAP256, an HIV-1 subtype C-infected (and subsequently superinfected) participant enrolled in the CAPRISA Acute Infection cohort was studied. A subset of mutants were tested for neutralization by PG9/PG16 along with neutralization of ConC by CAP256 plasma nAb. The epitope recognized by CAP256 is distinct from but overlaps that of PG9/PG16.Like CAP256 plasma, both PG9 and PG16 were heavily dependent on K169 and somewhat dependent on K171. A V2 mutation (N160A) had a profound affect on PG9 and PG16 but a more moderate affect on CAP256. The adjacent D167N residue also impacted CAP256 neutralization but not PG9/PG16, and a K168A mutation reduced CAP256 neutralization but in fact enhanced the neutralization of ConC by PG9/16. Both PG9/16 and CAP256, in the context of the ConC backbone, were slightly affected by mutations in the V3 loop (I305, I309, and F317) with mild effect on neutralization sensitivity. The I307A mutation affected both PG9/PG16 slightly but had no discernible effect on CAP256 neutralization. Some similarities between CAP256 and PG9/16 neutralization along with significant differences suggest that the epitopes recognized by these Abs overlapped but were not identical. Moore2011 (neutralization)
PG9: The impact of specific changes at distal sites on antibody binding and neutralization was examined on Q461 variants. The changes at position 675 in conjunction with Thr to Ala at position 569 resulted in a dramatic increase in the neutralization sensitivity to some gp41 and gp120 MAbs and plasma but had less effect on the more potent MAb VRC01. There was an increase in VRC01 neutralization sensitivity to viruses with both mutations with intermediate effect for the individual mutants. There was some detectable PG9 neutralization of the variant bearing the T569A mutation alone but PG9 neutralization was not achieved with a change at position 675 only. Lovelace2011 (antibody binding site, neutralization, variant cross-reactivity)
PG9: This review discusses current understanding of Env neutralization by antibodies in relation to epitope exposure and how this insight might benefit vaccine design strategies. This MAb is in the list of current MAbs with notable cross-neutralizing activity. Pantophlet2010 (neutralization, variant cross-reactivity, review)
PG9: This review outlines the general structure of the gp160 viral envelope, the dynamics of viral entry, the evolution of humoral response, the mechanisms of viral escape and the characterization of broadly neutralizing Abs. It is noted that this MAb shows a significant breadth of neutralization across all clades and extraordinary potency. Gonzalez2010 (neutralization, variant cross-reactivity, escape, review)
PG9: This review discusses recent rational structure-based approaches in HIV vaccine design that helped in understanding the link between Env antigenicity and immunogenicity. PG9 was isolated from a clade A infected donor using a high-throughput functional screening approach. This MAb was mentioned in the context of immunogens based on the epitopes recognized by bNAbs. Walker2010a (neutralization, review)
PG9: This review discusses the types of B-cell responses desired by HIV-1 vaccines and various methods used for eliciting HIV-1 inhibitory antibodies that include induction and characterization of vaccine-induces B-cell responses. PG9 was mentioned among new MAbs generated by isolating single Env-specific B cells by either single cell sorting by flow cytometry or from memory B-cell cultures coupled with high-throughput neutralization screening assays of B-cell supernatants. PG9 recognizes conserved regions of the variable loops in gp120 and is potent and broadly reactive against approximately 73-79% of HIV-1 strains. Tomaras2010 (review)
PG9: This review discusses strategies for design of neutralizing antibody-based vaccines against HIV-1 and recent major advances in the field regarding isolation of potent broadly neutralizing Abs. Sattentau2010 (review)
PG9: This review focuses on recent vaccine design efforts and investigation of broadly neutralizing Abs and their epitopes to aid in the improvement of immunogen design. NAb epitopes, NAbs response to HIV-1, isolation of novel mAbs, and vaccine-elicited NAb responses in human clinical trials are discussed in this review. Mascola2010 (review)
PG9: Unlike the MPER MAbs tested, PG9 did not show any Env-independent virus capture in the conventional or in the modified version of the virus capture assay. Leaman2010
PG9: Some of the key challenges for the development of an Ab-based HIV vaccine are discussed, such as challenges in identification of epitopes recognized by broadly neutralizing epitopes, the impact of biological mechanisms in addition to Ab neutralization, and the poor persistence of anti-Env Ab responses in the absence of continuous antigenic stimulation. Lewis2010 (review)
PG9: The role of HIV-1 envelope spike density on the virion and the effect it has on MAb avidity, and neutralization potencies of MAbs presented as different isotypes, are reviewed. Engineering approaches and design of immunogens able to elicit intra-spike cross-linking Abs are discussed. Klein2010 (review)
PG9: Novel techniques for generation of broadly neutralizing Abs and how these Ab can aid in development of an effective vaccine are discussed. Joyce2010 (review)
PG9: The review describes several different methods that have been used to isolate and characterize HIV MAbs within the human Ab repertoire. Relative advantages and limitations of methods such as EBV transformation, human hybridoma, non-immortalized B cell culture, combinatorial libraries from B cells and clonal sorting are discussed. Hammond2010 (review)
PG9: This review summarizes novel techniques recently developed for isolation of broadly neutralizing monoclonal Abs from HIV-infected donors. Future challenges and importance of these techniques for development of HIV vaccines is also discussed. Burton2010 (review)
PG9: PG9 epitope structure is reviewed. This review also summarizes data on the evolution of HIV neutralizing Abs, principles of Env immunogen design to elicit broadly neutralizing Abs, and future critical areas of research for development of an Ab-based HIV vaccine. Hoxie2010 (vaccine antigen design, review)
PG9: Novel methods for generation of broadly neutralizing Abs, such as PG9 and PG16 are reviewed. This review also summarizes PG9 and PG16 MAbs, and their similarity to 2909 MAb. Kwong2009 (review)
PG9: Removal of N-linked glycosylation sites was shown to generally lead to a reduction in neutralization sensitivity to PG9, however, the position of the N-linked glycosylation site removed and the magnitude of the effect was isolate dependent. Loss of glycosylation sites in the V1, V2 and V3 loops had greatest effect on reduced neutralization sensitivity. Removal of the N160 glycan was the only substitution that universally eliminated sensitivity to neutralization by PG9. Binding of PG9 to Env transfected cells and to gp120 was not competed by monosaccharides indicating that PG9 sensitivity to glycosylation was due to the effect of glycans on gp120 conformation and PG9 epitope accessibility. Doores2010 (antibody binding site, glycosylation, neutralization, binding affinity)
PG9: The CDR H3 region was shown critical for neutralization activity of the Ab. Affinity maturation of PG9 correlated with Ab neutralization breadth, as light chain V-gene reversion produced chimeric Abs with less neutralization. N-linked glycosylation of PG9 was not required for neutralization. Fab and IgG formats of PG9 had comparable neutralization potencies. The likely site of PG9 reaction with Env was determined to consist of CDR L1 and L2 and the CDR H3 elements. Pancera2010 (glycosylation, neutralization)
PG9: Broadly neutralizing sera from elite neutralizers exhibited significant sensitivities to mutations I165A, N332A, and N160K. PG9 neutralization activity was tested for pseudoviruses with the mutations relative to the WT. PG9 was shown to require N160K glycosylation for potent neutralizing activity. Pseudoviruses produced in cells treated with kifunensine were found resistant to PG9 neutralization. Donor sera that exhibited sensitivity to N160K showed diminished neutralizing activity against kifunensine-treated pseudoviruses, indicating that PG16 and PG9 MAbs mediate most of the sera neutralizing activity. PG16 and PG9 - like Ab were found in 21% of the donors. Walker2010 (glycosylation, neutralization)
PG9: Crystal structure of PG9 light chain was determined and a homology model of Fab PG9 was constructed for comparison to PG16 MAb. PG9 was shown to have a long CDR H3 that forms a unique stable subdomain. A 7-residue specificity loop within CDR H3 was shown to confer fine specificity of PG16 and PG9 MAbs, and to contain important contacts to gp120 as replacement of the 7 residues abolished PG9 neutralization. CDR H3 tyrosine for PG9 was doubly sulfated, and tyrosine sulfation was shown to play a role in both binding and neutralization. Glycosylation of PG9 light chain did not have a significant effect on neutralization. Pejchal2010 (glycosylation, neutralization, binding affinity, structure)
PG9: This MAb was derived from clade A infected patient. PG9 failed to bind to recombinant gp120 or gp41 but exhibited high neutralization breadth and potency, neutralizing 127 out of 162 cross-clade viruses with a potency exceeding that of b12, 2G12, and 2F5. PG9 also potently neutralized IAVI-C18 virus, that is neutralization resistant to all four bNAbs. PG9 competed for gp120 binding with Abs against V2, V3 and CD4i. N-glycosylation sites N156 and N160 in the V2 region were critical in forming PG9 epitope. PG9 preferred binding to trimeric Env due to subunit presentation in this form. This Ab had a long CDRH3 loop. Walker2009a (antibody generation, glycosylation, neutralization, variant cross-reactivity, binding affinity)

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Bradley2016a Todd Bradley, Ashley Trama, Nancy Tumba, Elin Gray, Xiaozhi Lu, Navid Madani, Fatemeh Jahanbakhsh, Amanda Eaton, Shi-Mao Xia, Robert Parks, Krissey E. Lloyd, Laura L. Sutherland, Richard M. Scearce, Cindy M. Bowman, Susan Barnett, Salim S. Abdool-Karim, Scott D. Boyd, Bruno Melillo, Amos B. Smith, 3rd., Joseph Sodroski, Thomas B. Kepler, S. Munir Alam, Feng Gao, Mattia Bonsignori, Hua-Xin Liao, M Anthony Moody, David Montefiori, Sampa Santra, Lynn Morris, and Barton F. Haynes. Amino Acid Changes in the HIV-1 gp41 Membrane Proximal Region Control Virus Neutralization Sensitivity. EBioMedicine, 12:196-207, Oct 2016. PubMed ID: 27612593. Show all entries for this paper.

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Cimbro2014 Raffaello Cimbro, Thomas R. Gallant, Michael A. Dolan, Christina Guzzo, Peng Zhang, Yin Lin, Huiyi Miao, Donald Van Ryk, James Arthos, Inna Gorshkova, Patrick H. Brown, Darrell E. Hurt, and Paolo Lusso. Tyrosine Sulfation in the Second Variable Loop (V2) of HIV-1 gp120 Stabilizes V2-V3 Interaction and Modulates Neutralization Sensitivity. Proc. Natl. Acad. Sci. U.S.A., 111(8):3152-3157, 25 Feb 2014. PubMed ID: 24569807. Show all entries for this paper.

Crooks2015 Ema T. Crooks, Tommy Tong, Bimal Chakrabarti, Kristin Narayan, Ivelin S. Georgiev, Sergey Menis, Xiaoxing Huang, Daniel Kulp, Keiko Osawa, Janelle Muranaka, Guillaume Stewart-Jones, Joanne Destefano, Sijy O'Dell, Celia LaBranche, James E. Robinson, David C. Montefiori, Krisha McKee, Sean X. Du, Nicole Doria-Rose, Peter D. Kwong, John R. Mascola, Ping Zhu, William R. Schief, Richard T. Wyatt, Robert G. Whalen, and James M. Binley. Vaccine-Elicited Tier 2 HIV-1 Neutralizing Antibodies Bind to Quaternary Epitopes Involving Glycan-Deficient Patches Proximal to the CD4 Binding Site. PLoS Pathog, 11(5):e1004932, May 2015. PubMed ID: 26023780. Show all entries for this paper.

Crooks2018 Ema T. Crooks, Samantha L. Grimley, Michelle Cully, Keiko Osawa, Gillian Dekkers, Kevin Saunders, Sebastian Ramisch, Sergey Menis, William R. Schief, Nicole Doria-Rose, Barton Haynes, Ben Murrell, Evan Mitchel Cale, Amarendra Pegu, John R. Mascola, Gestur Vidarsson, and James M. Binley. Glycoengineering HIV-1 Env Creates `Supercharged' and `Hybrid' Glycans to Increase Neutralizing Antibody Potency, Breadth and Saturation. PLoS Pathog., 14(5):e1007024, May 2018. PubMed ID: 29718999. Show all entries for this paper.

Davenport2011 Thaddeus M. Davenport, Della Friend, Katharine Ellingson, Hengyu Xu, Zachary Caldwell, George Sellhorn, Zane Kraft, Roland K. Strong, and Leonidas Stamatatos. Binding Interactions between Soluble HIV Envelope Glycoproteins and Quaternary-Structure-Specific Monoclonal Antibodies PG9 and PG16. J. Virol., 85(14):7095-7107, Jul 2011. PubMed ID: 21543501. Show all entries for this paper.

Decamp2014 Allan deCamp, Peter Hraber, Robert T. Bailer, Michael S. Seaman, Christina Ochsenbauer, John Kappes, Raphael Gottardo, Paul Edlefsen, Steve Self, Haili Tang, Kelli Greene, Hongmei Gao, Xiaoju Daniell, Marcella Sarzotti-Kelsoe, Miroslaw K. Gorny, Susan Zolla-Pazner, Celia C. LaBranche, John R. Mascola, Bette T. Korber, and David C. Montefiori. Global Panel of HIV-1 Env Reference Strains for Standardized Assessments of Vaccine-Elicited Neutralizing Antibodies. J. Virol., 88(5):2489-2507, Mar 2014. PubMed ID: 24352443. Show all entries for this paper.

Dennison2014 S. Moses Dennison, Kara M. Anasti, Frederick H. Jaeger, Shelley M. Stewart, Justin Pollara, Pinghuang Liu, Erika L. Kunz, Ruijun Zhang, Nathan Vandergrift, Sallie Permar, Guido Ferrari, Georgia D. Tomaras, Mattia Bonsignori, Nelson L. Michael, Jerome H Kim, Jaranit Kaewkungwal, Sorachai Nitayaphan, Punnee Pitisuttithum, Supachai Rerks-Ngarm, Hua-Xin Liao, Barton F. Haynes, and S. Munir Alam. Vaccine-Induced HIV-1 Envelope gp120 Constant Region 1-Specific Antibodies Expose a CD4-Inducible Epitope and Block the Interaction of HIV-1 gp140 with Galactosylceramide. J. Virol., 88(16):9406-9417, Aug 2014. PubMed ID: 24920809. Show all entries for this paper.

Derking2015 Ronald Derking, Gabriel Ozorowski, Kwinten Sliepen, Anila Yasmeen, Albert Cupo, Jonathan L. Torres, Jean-Philippe Julien, Jeong Hyun Lee, Thijs van Montfort, Steven W. de Taeye, Mark Connors, Dennis R. Burton, Ian A. Wilson, Per-Johan Klasse, Andrew B. Ward, John P. Moore, and Rogier W. Sanders. Comprehensive Antigenic Map of a Cleaved Soluble HIV-1 Envelope Trimer. PLoS Pathog, 11(3):e1004767, Mar 2015. PubMed ID: 25807248. Show all entries for this paper.

deTaeye2015 Steven W. de Taeye, Gabriel Ozorowski, Alba Torrents de la Peña, Miklos Guttman, Jean-Philippe Julien, Tom L. G. M. van den Kerkhof, Judith A. Burger, Laura K. Pritchard, Pavel Pugach, Anila Yasmeen, Jordan Crampton, Joyce Hu, Ilja Bontjer, Jonathan L. Torres, Heather Arendt, Joanne DeStefano, Wayne C. Koff, Hanneke Schuitemaker, Dirk Eggink, Ben Berkhout, Hansi Dean, Celia LaBranche, Shane Crotty, Max Crispin, David C. Montefiori, P. J. Klasse, Kelly K. Lee, John P. Moore, Ian A. Wilson, Andrew B. Ward, and Rogier W. Sanders. Immunogenicity of Stabilized HIV-1 Envelope Trimers with Reduced Exposure of Non-Neutralizing Epitopes. Cell, 163(7):1702-1715, 17 Dec 2015. PubMed ID: 26687358. Show all entries for this paper.

deTaeye2019 Steven W. de Taeye, Eden P. Go, Kwinten Sliepen, Alba Torrents de la Peña, Kimberly Badal, Max Medina-Ramírez, Wen-Hsin Lee, Heather Desaire, Ian A. Wilson, John P. Moore, Andrew B. Ward, and Rogier W. Sanders. Stabilization of the V2 Loop Improves the Presentation of V2 Loop-Associated Broadly Neutralizing Antibody Epitopes on HIV-1 Envelope Trimers. J. Biol. Chem., 294(14):5616-5631, 5 Apr 2019. PubMed ID: 30728245. Show all entries for this paper.

Diskin2013 Ron Diskin, Florian Klein, Joshua A. Horwitz, Ariel Halper-Stromberg, D. Noah Sather, Paola M. Marcovecchio, Terri Lee, Anthony P. West, Jr., Han Gao, Michael S. Seaman, Leonidas Stamatatos, Michel C. Nussenzweig, and Pamela J. Bjorkman. Restricting HIV-1 Pathways for Escape Using Rationally Designed Anti-HIV-1 Antibodies. J. Exp. Med., 210(6):1235-1249, 3 Jun 2013. PubMed ID: 23712429. Show all entries for this paper.

Doores2010 Katie J. Doores and Dennis R. Burton. Variable Loop Glycan Dependency of the Broad and Potent HIV-1-Neutralizing Antibodies PG9 and PG16. J. Virol., 84(20):10510-10521, Oct 2010. PubMed ID: 20686044. Show all entries for this paper.

Doria-Rose2012 Nicole A. Doria-Rose, Mark K. Louder, Zhongjia Yang, Sijy O'Dell, Martha Nason, Stephen D. Schmidt, Krisha McKee, Michael S. Seaman, Robert T. Bailer, and John R. Mascola. HIV-1 Neutralization Coverage Is Improved by Combining Monoclonal Antibodies That Target Independent Epitopes. J. Virol., 86(6):3393-3397, Mar 2012. PubMed ID: 22258252. Show all entries for this paper.

Doria-Rose2014 Nicole A. Doria-Rose, Chaim A. Schramm, Jason Gorman, Penny L. Moore, Jinal N. Bhiman, Brandon J. DeKosky, Michael J. Ernandes, Ivelin S. Georgiev, Helen J. Kim, Marie Pancera, Ryan P. Staupe, Han R. Altae-Tran, Robert T. Bailer, Ema T. Crooks, Albert Cupo, Aliaksandr Druz, Nigel J. Garrett, Kam H. Hoi, Rui Kong, Mark K. Louder, Nancy S. Longo, Krisha McKee, Molati Nonyane, Sijy O'Dell, Ryan S. Roark, Rebecca S. Rudicell, Stephen D. Schmidt, Daniel J. Sheward, Cinque Soto, Constantinos Kurt Wibmer, Yongping Yang, Zhenhai Zhang, NISC Comparative Sequencing Program, James C. Mullikin, James M. Binley, Rogier W. Sanders, Ian A. Wilson, John P. Moore, Andrew B. Ward, George Georgiou, Carolyn Williamson, Salim S. Abdool Karim, Lynn Morris, Peter D. Kwong, Lawrence Shapiro, and John R. Mascola. Developmental Pathway for Potent V1V2-Directed HIV-Neutralizing Antibodies. Nature, 509(7498):55-62, 1 May 2014. PubMed ID: 24590074. Show all entries for this paper.

Doria-Rose2017 Nicole A. Doria-Rose, Han R. Altae-Tran, Ryan S. Roark, Stephen D. Schmidt, Matthew S. Sutton, Mark K. Louder, Gwo-Yu Chuang, Robert T. Bailer, Valerie Cortez, Rui Kong, Krisha McKee, Sijy O'Dell, Felicia Wang, Salim S. Abdool Karim, James M. Binley, Mark Connors, Barton F. Haynes, Malcolm A. Martin, David C. Montefiori, Lynn Morris, Julie Overbaugh, Peter D. Kwong, John R. Mascola, and Ivelin S. Georgiev. Mapping Polyclonal HIV-1 Antibody Responses via Next-Generation Neutralization Fingerprinting. PLoS Pathog., 13(1):e1006148, Jan 2017. PubMed ID: 28052137. Show all entries for this paper.

Doria-RoseNA2012 Nicole A. Doria-Rose, Ivelin Georgiev, Sijy O'Dell, Gwo-Yu Chuang, Ryan P. Staupe, Jason S. McLellan, Jason Gorman, Marie Pancera, Mattia Bonsignori, Barton F. Haynes, Dennis R. Burton, Wayne C. Koff, Peter D. Kwong, and John R. Mascola. A Short Segment of the HIV-1 gp120 V1/V2 Region Is a Major Determinant of Resistance to V1/V2 Neutralizing Antibodies. J. Virol., Aug 2012. PubMed ID: 22623764. Show all entries for this paper.

Euler2011 Zelda Euler, Evelien M. Bunnik, Judith A. Burger, Brigitte D. M. Boeser-Nunnink, Marlous L. Grijsen, Jan M. Prins, and Hanneke Schuitemaker. Activity of Broadly Neutralizing Antibodies, Including PG9, PG16, and VRC01, against Recently Transmitted Subtype B HIV-1 Variants from Early and Late in the Epidemic. J. Virol., 85(14):7236-7245, Jul 2011. PubMed ID: 21561918. Show all entries for this paper.

Evans2014 Mark C. Evans, Pham Phung, Agnes C. Paquet, Anvi Parikh, Christos J. Petropoulos, Terri Wrin, and Mojgan Haddad. Predicting HIV-1 Broadly Neutralizing Antibody Epitope Networks Using Neutralization Titers and a Novel Computational Method. BMC Bioinformatics, 15:77, 19 Mar 2014. PubMed ID: 24646213. Show all entries for this paper.

Falkowska2012 Emilia Falkowska, Alejandra Ramos, Yu Feng, Tongqing Zhou, Stephanie Moquin, Laura M. Walker, Xueling Wu, Michael S. Seaman, Terri Wrin, Peter D. Kwong, Richard T. Wyatt, John R. Mascola, Pascal Poignard, and Dennis R. Burton. PGV04, an HIV-1 gp120 CD4 Binding Site Antibody, Is Broad and Potent in Neutralization but Does Not Induce Conformational Changes Characteristic of CD4. J. Virol., 86(8):4394-4403, Apr 2012. PubMed ID: 22345481. Show all entries for this paper.

Falkowska2014 Emilia Falkowska, Khoa M. Le, Alejandra Ramos, Katie J. Doores, Jeong Hyun Lee, Claudia Blattner, Alejandro Ramirez, Ronald Derking, Marit J. van Gils, Chi-Hui Liang, Ryan Mcbride, Benjamin von Bredow, Sachin S. Shivatare, Chung-Yi Wu, Po-Ying Chan-Hui, Yan Liu, Ten Feizi, Michael B. Zwick, Wayne C. Koff, Michael S. Seaman, Kristine Swiderek, John P. Moore, David Evans, James C. Paulson, Chi-Huey Wong, Andrew B. Ward, Ian A. Wilson, Rogier W. Sanders, Pascal Poignard, and Dennis R. Burton. Broadly Neutralizing HIV Antibodies Define a Glycan-Dependent Epitope on the Prefusion Conformation of gp41 on Cleaved Envelope Trimers. Immunity, 40(5):657-668, 15 May 2014. PubMed ID: 24768347. Show all entries for this paper.

Gach2013 Johannes S. Gach, Heribert Quendler, Tommy Tong, Kristin M. Narayan, Sean X. Du, Robert G. Whalen, James M. Binley, Donald N. Forthal, Pascal Poignard, and Michael B. Zwick. A Human Antibody to the CD4 Binding Site of gp120 Capable of Highly Potent but Sporadic Cross Clade Neutralization of Primary HIV-1. PLoS One, 8(8):e72054, 2013. PubMed ID: 23991039. Show all entries for this paper.

Gavrilyuk2013 Julia Gavrilyuk, Hitoshi Ban, Hisatoshi Uehara, Shannon J. Sirk, Karen Saye-Francisco, Angelica Cuevas, Elise Zablowsky, Avinash Oza, Michael S. Seaman, Dennis R. Burton, and Carlos F. Barbas, 3rd. Antibody Conjugation Approach Enhances Breadth and Potency of Neutralization of Anti-HIV-1 Antibodies and CD4-IgG. J. Virol., 87(9):4985-4993, May 2013. PubMed ID: 23427154. Show all entries for this paper.

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Gonzalez2010 Nuria Gonzalez, Amparo Alvarez, and Jose Alcami. Broadly Neutralizing Antibodies and their Significance for HIV-1 Vaccines. Curr. HIV Res., 8(8):602-612, Dec 2010. PubMed ID: 21054253. Show all entries for this paper.

Goo2012 Leslie Goo, Zahra Jalalian-Lechak, Barbra A. Richardson, and Julie Overbaugh. A Combination of Broadly Neutralizing HIV-1 Monoclonal Antibodies Targeting Distinct Epitopes Effectively Neutralizes Variants Found in Early Infection. J. Virol., 86(19):10857-10861, Oct 2012. PubMed ID: 22837204. Show all entries for this paper.

Gorman2016 Jason Gorman, Cinque Soto, Max M. Yang, Thaddeus M. Davenport, Miklos Guttman, Robert T. Bailer, Michael Chambers, Gwo-Yu Chuang, Brandon J. DeKosky, Nicole A. Doria-Rose, Aliaksandr Druz, Michael J. Ernandes, Ivelin S. Georgiev, Marissa C. Jarosinski, M. Gordon Joyce, Thomas M. Lemmin, Sherman Leung, Mark K. Louder, Jonathan R. McDaniel, Sandeep Narpala, Marie Pancera, Jonathan Stuckey, Xueling Wu, Yongping Yang, Baoshan Zhang, Tongqing Zhou, NISC Comparative Sequencing Program, James C. Mullikin, Ulrich Baxa, George Georgiou, Adrian B. McDermott, Mattia Bonsignori, Barton F. Haynes, Penny L. Moore, Lynn Morris, Kelly K. Lee, Lawrence Shapiro, John R. Mascola, and Peter D. Kwong. Structures of HIV-1 Env V1V2 with Broadly Neutralizing Antibodies Reveal Commonalities That Enable Vaccine Design. Nat. Struct. Mol. Biol., 23(1):81-90, Jan 2016. PubMed ID: 26689967. Show all entries for this paper.

Guan2013 Yongjun Guan, Marzena Pazgier, Mohammad M. Sajadi, Roberta Kamin-Lewis, Salma Al-Darmarki, Robin Flinko, Elena Lovo, Xueji Wu, James E. Robinson, Michael S. Seaman, Timothy R. Fouts, Robert C. Gallo, Anthony L. DeVico, and George K. Lewis. Diverse Specificity and Effector Function Among Human Antibodies to HIV-1 Envelope Glycoprotein Epitopes Exposed by CD4 Binding. Proc. Natl. Acad. Sci. U.S.A., 110(1):E69-E78, 2 Jan 2013. PubMed ID: 23237851. Show all entries for this paper.

Guzzo2018 Christina Guzzo, Peng Zhang, Qingbo Liu, Alice L. Kwon, Ferzan Uddin, Alexandra I. Wells, Hana Schmeisser, Raffaello Cimbro, Jinghe Huang, Nicole Doria-Rose, Stephen D. Schmidt, Michael A. Dolan, Mark Connors, John R. Mascola, and Paolo Lusso. Structural Constraints at the Trimer Apex Stabilize the HIV-1 Envelope in a Closed, Antibody-Protected Conformation. mBio, 9(6), 11 Dec 2018. PubMed ID: 30538178. Show all entries for this paper.

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Haynes2013 Barton F. Haynes and M. Juliana McElrath. Progress in HIV-1 Vaccine Development. Curr. Opin. HIV AIDS, 8(4):326-332, Jul 2013. PubMed ID: 23743722. Show all entries for this paper.

Henderson2019 Rory Henderson, Brian E. Watts, Hieu N. Ergin, Kara Anasti, Robert Parks, Shi-Mao Xia, Ashley Trama, Hua-Xin Liao, Kevin O. Saunders, Mattia Bonsignori, Kevin Wiehe, Barton F. Haynes, and S. Munir Alam. Selection of Immunoglobulin Elbow Region Mutations Impacts Interdomain Conformational Flexibility in HIV-1 Broadly Neutralizing Antibodies. Nat. Commun., 10(1):654, 8 Feb 2019. PubMed ID: 30737386. Show all entries for this paper.

Hoffenberg2013 Simon Hoffenberg, Rebecca Powell, Alexei Carpov, Denise Wagner, Aaron Wilson, Sergei Kosakovsky Pond, Ross Lindsay, Heather Arendt, Joanne DeStefano, Sanjay Phogat, Pascal Poignard, Steven P. Fling, Melissa Simek, Celia LaBranche, David Montefiori, Terri Wrin, Pham Phung, Dennis Burton, Wayne Koff, C. Richter King, Christopher L. Parks, and Michael J. Caulfield. Identification of an HIV-1 Clade A Envelope That Exhibits Broad Antigenicity and Neutralization Sensitivity and Elicits Antibodies Targeting Three Distinct Epitopes. J. Virol., 87(10):5372-5383, May 2013. PubMed ID: 23468492. Show all entries for this paper.

Hogan2018 Michael J. Hogan, Angela Conde-Motter, Andrea P. O. Jordan, Lifei Yang, Brad Cleveland, Wenjin Guo, Josephine Romano, Houping Ni, Norbert Pardi, Celia C. LaBranche, David C. Montefiori, Shiu-Lok Hu, James A. Hoxie, and Drew Weissman. Increased Surface Expression of HIV-1 Envelope Is Associated with Improved Antibody Response in Vaccinia Prime/Protein Boost Immunization. Virology, 514:106-117, 15 Jan 2018. PubMed ID: 29175625. Show all entries for this paper.

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Hraber2014 Peter Hraber, Michael S. Seaman, Robert T. Bailer, John R. Mascola, David C. Montefiori, and Bette T. Korber. Prevalence of Broadly Neutralizing Antibody Responses during Chronic HIV-1 Infection. AIDS, 28(2):163-169, 14 Jan 2014. PubMed ID: 24361678. Show all entries for this paper.

Hraber2017 Peter Hraber, Cecilia Rademeyer, Carolyn Williamson, Michael S. Seaman, Raphael Gottardo, Haili Tang, Kelli Greene, Hongmei Gao, Celia LaBranche, John R. Mascola, Lynn Morris, David C. Montefiori, and Bette Korber. Panels of HIV-1 Subtype C Env Reference Strains for Standardized Neutralization Assessments. J. Virol., 91(19), 1 Oct 2017. PubMed ID: 28747500. Show all entries for this paper.

Hraber2018 Peter Hraber, Bette Korber, Kshitij Wagh, David Montefiori, and Mario Roederer. A Single, Continuous Metric To Define Tiered Serum Neutralization Potency against Hiv. eLife, 7, 19 Jan 2018. PubMed ID: 29350181. Show all entries for this paper.

Hu2015 Joyce K. Hu, Jordan C. Crampton, Albert Cupo, Thomas Ketas, Marit J. van Gils, Kwinten Sliepen, Steven W. de Taeye, Devin Sok, Gabriel Ozorowski, Isaiah Deresa, Robyn Stanfield, Andrew B. Ward, Dennis R. Burton, Per Johan Klasse, Rogier W. Sanders, John P. Moore, and Shane Crotty. Murine Antibody Responses to Cleaved Soluble HIV-1 Envelope Trimers Are Highly Restricted in Specificity. J. Virol., 89(20):10383-10398, Oct 2015. PubMed ID: 26246566. Show all entries for this paper.

Hua2016 Casey K. Hua and Margaret E. Ackerman. Engineering Broadly Neutralizing Antibodies for HIV Prevention and Therapy. Adv. Drug Deliv. Rev., 103:157-173, 1 Aug 2016. PubMed ID: 26827912. Show all entries for this paper.

Huang2012a Jinghe Huang, Gilad Ofek, Leo Laub, Mark K. Louder, Nicole A. Doria-Rose, Nancy S. Longo, Hiromi Imamichi, Robert T. Bailer, Bimal Chakrabarti, Shailendra K. Sharma, S. Munir Alam, Tao Wang, Yongping Yang, Baoshan Zhang, Stephen A. Migueles, Richard Wyatt, Barton F. Haynes, Peter D. Kwong, John R. Mascola, and Mark Connors. Broad and Potent Neutralization of HIV-1 by a gp41-Specific Human Antibody. Nature, 491(7424):406-412, 15 Nov 2012. PubMed ID: 23151583. Show all entries for this paper.

Hutchinson2019 Jennie M. Hutchinson, Kathryn A. Mesa, David L. Alexander, Bin Yu, Sara M. O'Rourke, Kay L. Limoli, Terri Wrin, Steven G. Deeks, and Phillip W. Berman. Unusual Cysteine Content in V1 Region of gp120 from an Elite Suppressor That Produces Broadly Neutralizing Antibodies. Front. Immunol., 10:1021, 2019. PubMed ID: 31156622. Show all entries for this paper.

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Joyce2010 Joseph G. Joyce and Jan ter Meulen. Pushing the Envelope on HIV-1 Neutralization. Nat. Biotechnol., 28(9):929-931, Sep 2010. PubMed ID: 20829830. Show all entries for this paper.

Julien2013 Jean-Philippe Julien, Jeong Hyun Lee, Albert Cupo, Charles D. Murin, Ronald Derking, Simon Hoffenberg, Michael J. Caulfield, C. Richter King, Andre J. Marozsan, Per Johan Klasse, Rogier W. Sanders, John P. Moore, Ian A. Wilson, and Andrew. B Ward. Asymmetric Recognition of the HIV-1 Trimer by Broadly Neutralizing Antibody PG9. Proc. Natl. Acad. Sci. U.S.A., 110(11):4351-4356, 12 Mar 2013. PubMed ID: 23426631. Show all entries for this paper.

Julien2015 Jean-Philippe Julien, Jeong Hyun Lee, Gabriel Ozorowski, Yuanzi Hua, Alba Torrents de la Peña, Steven W. de Taeye, Travis Nieusma, Albert Cupo, Anila Yasmeen, Michael Golabek, Pavel Pugach, P. J. Klasse, John P. Moore, Rogier W. Sanders, Andrew B. Ward, and Ian A. Wilson. Design and Structure of Two HIV-1 Clade C SOSIP.664 Trimers That Increase the Arsenal of Native-Like Env Immunogens. Proc. Natl. Acad. Sci. U.S.A., 112(38):11947-11952, 22 Sep 2015. PubMed ID: 26372963. Show all entries for this paper.

Kesavardhana2017 Sannula Kesavardhana, Raksha Das, Michael Citron, Rohini Datta, Linda Ecto, Nonavinakere Seetharam Srilatha, Daniel DiStefano, Ryan Swoyer, Joseph G. Joyce, Somnath Dutta, Celia C. LaBranche, David C. Montefiori, Jessica A. Flynn, and Raghavan Varadarajan. Structure-Based Design of Cyclically Permuted HIV-1 gp120 Trimers That Elicit Neutralizing Antibodies. J. Biol. Chem., 292(1):278-291, 6 Jan 2017. PubMed ID: 27879316. Show all entries for this paper.

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Kovacs2012 James M. Kovacs, Joseph P. Nkolola, Hanqin Peng, Ann Cheung, James Perry, Caroline A. Miller, Michael S. Seaman, Dan H. Barouch, and Bing Chen. HIV-1 Envelope Trimer Elicits More Potent Neutralizing Antibody Responses than Monomeric gp120. Proc. Natl. Acad. Sci. U.S.A., 109(30):12111-12116, 24 Jul 2012. PubMed ID: 22773820. Show all entries for this paper.

Kwon2012 Young Do Kwon, Andrés Finzi, Xueling Wu, Cajetan Dogo-Isonagie, Lawrence K. Lee, Lucas R. Moore, Stephen D. Schmidt, Jonathan Stuckey, Yongping Yang, Tongqing Zhou, Jiang Zhu, David A. Vicic, Asim K. Debnath, Lawrence Shapiro, Carole A. Bewley, John R. Mascola, Joseph G. Sodroski, and Peter D. Kwong. Unliganded HIV-1 gp120 Core Structures Assume the CD4-Bound Conformation with Regulation by Quaternary Interactions and Variable Loops. Proc. Natl. Acad. Sci. U.S.A., 109(15):5663-5668, 10 Apr 2012. PubMed ID: 22451932. Show all entries for this paper.

Kwong2009 Peter D. Kwong, John R. Mascola, and Gary J. Nabel. Mining the B Cell Repertoire for Broadly Neutralizing Monoclonal Antibodies to HIV-1. Cell Host Microbe, 6(4):292-294, 22 Oct 2009. PubMed ID: 19837366. Show all entries for this paper.

Kwong2011 Peter D. Kwong, John R. Mascola, and Gary J. Nabel. Rational Design of Vaccines to Elicit Broadly Neutralizing Antibodies to HIV-1. Cold Spring Harb. Perspect. Med., 1(1):a007278, Sep 2011. PubMed ID: 22229123. Show all entries for this paper.

Kwong2012 Peter D. Kwong and John R. Mascola. Human Antibodies that Neutralize HIV-1: Identification, Structures, and B Cell Ontogenies. Immunity, 37(3):412-425, 21 Sep 2012. PubMed ID: 22999947. Show all entries for this paper.

Kwong2013 Peter D. Kwong, John R. Mascola, and Gary J. Nabel. Broadly Neutralizing Antibodies and the Search for an HIV-1 Vaccine: The End of the Beginning. Nat. Rev. Immunol., 13(9):693-701, Sep 2013. PubMed ID: 23969737. Show all entries for this paper.

Kwong2018 Peter D. Kwong and John R. Mascola. HIV-1 Vaccines Based on Antibody Identification, B Cell Ontogeny, and Epitope Structure. Immunity, 48(5):855-871, 15 May 2018. PubMed ID: 29768174. Show all entries for this paper.

Lavine2012 Christy L. Lavine, Socheata Lao, David C. Montefiori, Barton F. Haynes, Joseph G. Sodroski, Xinzhen Yang, and NIAID Center for HIV/AIDS Vaccine Immunology (CHAVI). High-Mannose Glycan-Dependent Epitopes Are Frequently Targeted in Broad Neutralizing Antibody Responses during Human Immunodeficiency Virus Type 1 Infection. J. Virol., 86(4):2153-2164, Feb 2012. PubMed ID: 22156525. Show all entries for this paper.

Leaman2010 Daniel P. Leaman, Heather Kinkead, and Michael B. Zwick. In-Solution Virus Capture Assay Helps Deconstruct Heterogeneous Antibody Recognition of Human Immunodeficiency Virus Type 1. J. Virol., 84(7):3382-3395, Apr 2010. PubMed ID: 20089658. Show all entries for this paper.

Lee2017 Jeong Hyun Lee, Raiees Andrabi, Ching-Yao Su, Anila Yasmeen, Jean-Philippe Julien, Leopold Kong, Nicholas C. Wu, Ryan McBride, Devin Sok, Matthias Pauthner, Christopher A. Cottrell, Travis Nieusma, Claudia Blattner, James C. Paulson, Per Johan Klasse, Ian A. Wilson, Dennis R. Burton, and Andrew B. Ward. A Broadly Neutralizing Antibody Targets the Dynamic HIV Envelope Trimer Apex via a Long, Rigidified, and Anionic beta-Hairpin Structure. Immunity, 46(4):690-702, 18 Apr 2017. PubMed ID: 28423342. Show all entries for this paper.

Lewis2010 George K. Lewis. Challenges of Antibody-Mediated Protection against HIV-1. Expert Rev. Vaccines, 9(7):683-687, Jul 2010. PubMed ID: 20624038. Show all entries for this paper.

Li2017 Hongru Li, Chati Zony, Ping Chen, and Benjamin K. Chen. Reduced Potency and Incomplete Neutralization of Broadly Neutralizing Antibodies against Cell-to-Cell Transmission of HIV-1 with Transmitted Founder Envs. J. Virol., 91(9), 1 May 2017. PubMed ID: 28148796. Show all entries for this paper.

Liang2016 Yu Liang, Miklos Guttman, James A. Williams, Hans Verkerke, Daniel Alvarado, Shiu-Lok Hu, and Kelly K. Lee. Changes in Structure and Antigenicity of HIV-1 Env Trimers Resulting from Removal of a Conserved CD4 Binding Site-Proximal Glycan. J. Virol., 90(20):9224-9236, 15 Oct 2016. PubMed ID: 27489265. Show all entries for this paper.

Liao2013b Hua-Xin Liao, Mattia Bonsignori, S. Munir Alam, Jason S. McLellan, Georgia D. Tomaras, M. Anthony Moody, Daniel M. Kozink, Kwan-Ki Hwang, Xi Chen, Chun-Yen Tsao, Pinghuang Liu, Xiaozhi Lu, Robert J. Parks, David C. Montefiori, Guido Ferrari, Justin Pollara, Mangala Rao, Kristina K. Peachman, Sampa Santra, Norman L. Letvin, Nicos Karasavvas, Zhi-Yong Yang, Kaifan Dai, Marie Pancera, Jason Gorman, Kevin Wiehe, Nathan I. Nicely, Supachai Rerks-Ngarm, Sorachai Nitayaphan, Jaranit Kaewkungwal, Punnee Pitisuttithum, James Tartaglia, Faruk Sinangil, Jerome H. Kim, Nelson L. Michael, Thomas B. Kepler, Peter D. Kwong, John R. Mascola, Gary J. Nabel, Abraham Pinter, Susan Zolla-Pazner, and Barton F. Haynes. Vaccine Induction of Antibodies Against a Structurally Heterogeneous Site of Immune Pressure within HIV-1 Envelope Protein Variable Regions 1 and 2. Immunity, 38(1):176-186, 24 Jan 2013. PubMed ID: 23313589. Show all entries for this paper.

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Liu2011 Lihong Liu, Michael Wen, Weiming Wang, Shumei Wang, Lifei Yang, Yong Liu, Mengran Qian, Linqi Zhang, Yiming Shao, Jason T. Kimata, and Paul Zhou. Potent and Broad Anti-HIV-1 Activity Exhibited by a Glycosyl-Phosphatidylinositol-Anchored Peptide Derived from the CDR H3 of Broadly Neutralizing Antibody PG16. J. Virol., 85(17):8467-8476, Sep 2011. PubMed ID: 21715497. Show all entries for this paper.

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Liu2015a Mengfei Liu, Guang Yang, Kevin Wiehe, Nathan I. Nicely, Nathan A. Vandergrift, Wes Rountree, Mattia Bonsignori, S. Munir Alam, Jingyun Gao, Barton F. Haynes, and Garnett Kelsoe. Polyreactivity and Autoreactivity among HIV-1 Antibodies. J. Virol., 89(1):784-798, Jan 2015. PubMed ID: 25355869. Show all entries for this paper.

Lovelace2011 Erica Lovelace, Hengyu Xu, Catherine A. Blish, Roland Strong, and Julie Overbaugh. The Role of Amino Acid Changes in the Human Immunodeficiency Virus Type 1 Transmembrane Domain in Antibody Binding and Neutralization. Virology, 421(2):235-244, 20 Dec 2011. PubMed ID: 22029936. Show all entries for this paper.

Lynch2011 John B. Lynch, Ruth Nduati, Catherine A. Blish, Barbra A. Richardson, Jennifer M. Mabuka, Zahra Jalalian-Lechak, Grace John-Stewart, and Julie Overbaugh. The Breadth and Potency of Passively Acquired Human Immunodeficiency Virus Type 1-Specific Neutralizing Antibodies Do Not Correlate with the Risk of Infant Infection. J. Virol., 85(11):5252-5261, Jun 2011. PubMed ID: 21411521. Show all entries for this paper.

Magnus2016 Carsten Magnus, Lucia Reh, and Alexandra Trkola. HIV-1 Resistance to Neutralizing Antibodies: Determination of Antibody Concentrations Leading to Escape Mutant Evolution. Virus Res., 218:57-70, 15 Jun 2016. PubMed ID: 26494166. Show all entries for this paper.

Mao2012 Youdong Mao, Liping Wang, Christopher Gu, Alon Herschhorn, Shi-Hua Xiang, Hillel Haim, Xinzhen Yang, and Joseph Sodroski. Subunit Organization of the Membrane-Bound HIV-1 Envelope Glycoprotein Trimer. Nat. Struct. Mol. Biol., 19(9):893-899, Sep 2012. PubMed ID: 22864288. Show all entries for this paper.

Mascola2010 John R. Mascola and David C. Montefiori. The Role of Antibodies in HIV Vaccines. Annu. Rev. Immunol., 28:413-444, Mar 2010. PubMed ID: 20192810. Show all entries for this paper.

McCoy2015 Laura E. McCoy, Emilia Falkowska, Katie J. Doores, Khoa Le, Devin Sok, Marit J. van Gils, Zelda Euler, Judith A. Burger, Michael S. Seaman, Rogier W. Sanders, Hanneke Schuitemaker, Pascal Poignard, Terri Wrin, and Dennis R. Burton. Incomplete Neutralization and Deviation from Sigmoidal Neutralization Curves for HIV Broadly Neutralizing Monoclonal Antibodies. PLoS Pathog., 11(8):e1005110, Aug 2015. PubMed ID: 26267277. Show all entries for this paper.

McGuire2014 Andrew T. McGuire, Jolene A. Glenn, Adriana Lippy, and Leonidas Stamatatos. Diverse Recombinant HIV-1 Envs Fail to Activate B Cells Expressing the Germline B Cell Receptors of the Broadly Neutralizing Anti-HIV-1 Antibodies PG9 and 447-52D. J. Virol., 88(5):2645-2657, Mar 2014. PubMed ID: 24352455. Show all entries for this paper.

McLellan2011 Jason S. McLellan, Marie Pancera, Chris Carrico, Jason Gorman, Jean-Philippe Julien, Reza Khayat, Robert Louder, Robert Pejchal, Mallika Sastry, Kaifan Dai, Sijy O'Dell, Nikita Patel, Syed Shahzad-ul-Hussan, Yongping Yang, Baoshan Zhang, Tongqing Zhou, Jiang Zhu, Jeffrey C. Boyington, Gwo-Yu Chuang, Devan Diwanji, Ivelin Georgiev, Young Do Kwon, Doyung Lee, Mark K. Louder, Stephanie Moquin, Stephen D. Schmidt, Zhi-Yong Yang, Mattia Bonsignori, John A. Crump, Saidi H. Kapiga, Noel E. Sam, Barton F. Haynes, Dennis R. Burton, Wayne C. Koff, Laura M. Walker, Sanjay Phogat, Richard Wyatt, Jared Orwenyo, Lai-Xi Wang, James Arthos, Carole A. Bewley, John R. Mascola, Gary J. Nabel, William R. Schief, Andrew B. Ward, Ian A. Wilson, and Peter D. Kwong. Structure of HIV-1 gp120 V1/V2 Domain with Broadly Neutralizing Antibody PG9. Nature, 480(7377):336-343, 15 Dec 2011. PubMed ID: 22113616. Show all entries for this paper.

McLinden2013 Robert J. McLinden, Celia C. LaBranche, Agnès-Laurence Chenine, Victoria R. Polonis, Michael A. Eller, Lindsay Wieczorek, Christina Ochsenbauer, John C. Kappes, Stephen Perfetto, David C. Montefiori, Nelson L. Michael, and Jerome H. Kim. Detection of HIV-1 Neutralizing Antibodies in a Human CD4+/CXCR4+/CCR5+ T-Lymphoblastoid Cell Assay System. PLoS One, 8(11):e77756, 2013. PubMed ID: 24312168. Show all entries for this paper.

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Mikell2012 Iliyana Mikell and Leonidas Stamatatos. Evolution of Cross-Neutralizing Antibody Specificities to the CD4-BS and the Carbohydrate Cloak of the HIV Env in an HIV-1-Infected Subject. PLoS One, 7(11):e49610, 2012. PubMed ID: 23152926. Show all entries for this paper.

Moore2011 Penny L. Moore, Elin S. Gray, Daniel Sheward, Maphuti Madiga, Nthabeleng Ranchobe, Zhong Lai, William J. Honnen, Molati Nonyane, Nancy Tumba, Tandile Hermanus, Sengeziwe Sibeko, Koleka Mlisana, Salim S. Abdool Karim, Carolyn Williamson, Abraham Pinter, Lynn Morris, and CAPRISA 002 Study. Potent and Broad Neutralization of HIV-1 Subtype C by Plasma Antibodies Targeting a Quaternary Epitope Including Residues in the V2 loop. J. Virol., 85(7):3128-3141, Apr 2011. PubMed ID: 21270156. Show all entries for this paper.

Moore2012 Penny L. Moore, Elin S. Gray, C. Kurt Wibmer, Jinal N. Bhiman, Molati Nonyane, Daniel J. Sheward, Tandile Hermanus, Shringkhala Bajimaya, Nancy L. Tumba, Melissa-Rose Abrahams, Bronwen E. Lambson, Nthabeleng Ranchobe, Lihua Ping, Nobubelo Ngandu, Quarraisha Abdool Karim, Salim S. Abdool Karim, Ronald I. Swanstrom, Michael S. Seaman, Carolyn Williamson, and Lynn Morris. Evolution of an HIV Glycan-Dependent Broadly Neutralizing Antibody Epitope through Immune Escape. Nat. Med., 18(11):1688-1692, Nov 2012. PubMed ID: 23086475. Show all entries for this paper.

Morales2016 Javier F. Morales, Bin Yu, Gerardo Perez, Kathryn A. Mesa, David L. Alexander, and Phillip W. Berman. Fragments of the V1/V2 Domain of HIV-1 Glycoprotein 120 Engineered for Improved Binding to the Broadly Neutralizing PG9 antibody. Mol. Immunol., 77:14-25, Sep 2016. PubMed ID: 27449907. Show all entries for this paper.

Morgand2015 Marion Morgand, Mélanie Bouvin-Pley, Jean-Christophe Plantier, Alain Moreau, Elodie Alessandri, François Simon, Craig S. Pace, Marie Pancera, David D. Ho, Pascal Poignard, Pamela J. Bjorkman, Hugo Mouquet, Michel C. Nussenzweig, Peter D. Kwong, Daniel Baty, Patrick Chames, Martine Braibant, and Francis Barin. A V1V2 Neutralizing Epitope Is Conserved in Divergent Non-M Groups of HIV-1. J. Acquir. Immune Defic. Syndr., 21 Sep 2015. PubMed ID: 26413851. Show all entries for this paper.

Mouquet2011 Hugo Mouquet, Florian Klein, Johannes F. Scheid, Malte Warncke, John Pietzsch, Thiago Y. K. Oliveira, Klara Velinzon, Michael S. Seaman, and Michel C. Nussenzweig. Memory B Cell Antibodies to HIV-1 gp140 Cloned from Individuals Infected with Clade A and B Viruses. PLoS One, 6(9):e24078, 2011. PubMed ID: 21931643. Show all entries for this paper.

Mouquet2012a Hugo Mouquet, Louise Scharf, Zelda Euler, Yan Liu, Caroline Eden, Johannes F. Scheid, Ariel Halper-Stromberg, Priyanthi N. P. Gnanapragasam, Daniel I. R. Spencer, Michael S. Seaman, Hanneke Schuitemaker, Ten Feizi, Michel C. Nussenzweig, and Pamela J. Bjorkman. Complex-Type N-Glycan Recognition by Potent Broadly Neutralizing HIV Antibodies. Proc. Natl. Acad. Sci. U.S.A, 109(47):E3268-E3277, 20 Nov 2012. PubMed ID: 23115339. Show all entries for this paper.

Nie2020 Jianhui Nie, Weijin Huang, Qiang Liu, and Youchun Wang. HIV-1 pseudoviruses constructed in China regulatory laboratory. Emerg Microbes Infect, 9(1):32-41 doi, 2020. PubMed ID: 31859609 Show all entries for this paper.

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ORourke2012 Sara M. O'Rourke, Becky Schweighardt, Pham Phung, Kathryn A. Mesa, Aaron L. Vollrath, Gwen P. Tatsuno, Briana To, Faruk Sinangil, Kay Limoli, Terri Wrin, and Phillip W. Berman. Sequences in Glycoprotein gp41, the CD4 Binding Site, and the V2 Domain Regulate Sensitivity and Resistance of HIV-1 to Broadly Neutralizing Antibodies. J. Virol., 86(22):12105-12114, Nov 2012. PubMed ID: 22933284. Show all entries for this paper.

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Pancera2013 Marie Pancera, Syed Shahzad-ul-Hussan, Nicole A. Doria-Rose, Jason S. McLellan, Robert T. Bailer, Kaifan Dai, Sandra Loesgen, Mark K. Louder, Ryan P. Staupe, Yongping Yang, Baoshan Zhang, Robert Parks, Joshua Eudailey, Krissey E. Lloyd, Julie Blinn, S. Munir Alam, Barton F. Haynes, Mohammed N. Amin, Lai-Xi Wang, Dennis R. Burton, Wayne C. Koff, Gary J. Nabel, John R. Mascola, Carole A. Bewley, and Peter D. Kwong. Structural Basis for Diverse N-Glycan Recognition by HIV-1-Neutralizing V1-V2-Directed Antibody PG16. Nat. Struct. Mol. Biol., 20(7):804-813, Jul 2013. PubMed ID: 23708607. Show all entries for this paper.

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Pegu2017 Amarendra Pegu, Ann J. Hessell, John R. Mascola, and Nancy L. Haigwood. Use of Broadly Neutralizing Antibodies for HIV-1 Prevention. Immunol. Rev., 275(1):296-312, Jan 2017. PubMed ID: 28133803. Show all entries for this paper.

Pejchal2010 Robert Pejchal, Laura M. Walker, Robyn L. Stanfield, Sanjay K. Phogat, Wayne C. Koff, Pascal Poignard, Dennis R. Burton, and Ian A. Wilson. Structure and Function of Broadly Reactive Antibody PG16 Reveal an H3 Subdomain That Mediates Potent Neutralization of HIV-1. Proc. Natl. Acad. Sci. U.S.A., 107(25):11483-11488, 22 Jun 2010. PubMed ID: 20534513. Show all entries for this paper.

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Pollara2013 Justin Pollara, Mattia Bonsignori, M. Anthony Moody, Marzena Pazgier, Barton F. Haynes, and Guido Ferrari. Epitope Specificity of Human Immunodeficiency Virus-1 Antibody Dependent Cellular Cytotoxicity (ADCC) Responses. Curr. HIV Res., 11(5):378-387, Jul 2013. PubMed ID: 24191939. Show all entries for this paper.

Prevost2018 Jérémie Prévost, Jonathan Richard, Shilei Ding, Beatriz Pacheco, Roxanne Charlebois, Beatrice H Hahn, Daniel E Kaufmann, and Andrés Finzi. Envelope Glycoproteins Sampling States 2/3 Are Susceptible to ADCC by Sera from HIV-1-Infected Individuals. Virology, 515:38-45, Feb 2018. PubMed ID: 29248757. Show all entries for this paper.

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Pugach2015 Pavel Pugach, Gabriel Ozorowski, Albert Cupo, Rajesh Ringe, Anila Yasmeen, Natalia de Val, Ronald Derking, Helen J. Kim, Jacob Korzun, Michael Golabek, Kevin de Los Reyes, Thomas J. Ketas, Jean-Philippe Julien, Dennis R. Burton, Ian A. Wilson, Rogier W. Sanders, P. J. Klasse, Andrew B. Ward, and John P. Moore. A Native-Like SOSIP.664 Trimer Based on an HIV-1 Subtype B env Gene. J. Virol., 89(6):3380-3395, Mar 2015. PubMed ID: 25589637. Show all entries for this paper.

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Ringe2011 Rajesh Ringe, Deepak Sharma, Susan Zolla-Pazner, Sanjay Phogat, Arun Risbud, Madhuri Thakar, Ramesh Paranjape, and Jayanta Bhattacharya. A Single Amino Acid Substitution in the C4 Region in gp120 Confers Enhanced Neutralization of HIV-1 by Modulating CD4 Binding Sites and V3 Loop. Virology, 418(2):123-132, 30 Sep 2011. PubMed ID: 21851958. Show all entries for this paper.

Ringe2012 Rajesh Ringe, Sanjay Phogat, and Jayanta Bhattacharya. Subtle Alteration of Residues Including N-Linked Glycans in V2 Loop Modulate HIV-1 Neutralization by PG9 and PG16 Monoclonal Antibodies. Virology, 426(1):34-41, 25 Apr 2012. PubMed ID: 22314018. Show all entries for this paper.

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Rusert2016 Peter Rusert, Roger D. Kouyos, Claus Kadelka, Hanna Ebner, Merle Schanz, Michael Huber, Dominique L. Braun, Nathanael Hozé, Alexandra Scherrer, Carsten Magnus, Jacqueline Weber, Therese Uhr, Valentina Cippa, Christian W. Thorball, Herbert Kuster, Matthias Cavassini, Enos Bernasconi, Matthias Hoffmann, Alexandra Calmy, Manuel Battegay, Andri Rauch, Sabine Yerly, Vincent Aubert, Thomas Klimkait, Jürg Böni, Jacques Fellay, Roland R. Regoes, Huldrych F. Günthard, Alexandra Trkola, and Swiss HIV Cohort Study. Determinants of HIV-1 Broadly Neutralizing Antibody Induction. Nat. Med., 22(11):1260-1267, Nov 2016. PubMed ID: 27668936. Show all entries for this paper.

Saha2012 Piyali Saha, Sanchari Bhattacharyya, Sannula Kesavardhana, Edward Roshan Miranda, P. Shaik Syed Ali, Deepak Sharma, and Raghavan Varadarajan. Designed Cyclic Permutants of HIV-1 gp120: Implications for Envelope Trimer Structure and Immunogen Design. Biochemistry, 51(9):1836-1847, 6 Mar 2012. PubMed ID: 22329717. Show all entries for this paper.

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Sanders2013 Rogier W. Sanders, Ronald Derking, Albert Cupo, Jean-Philippe Julien, Anila Yasmeen, Natalia de Val, Helen J. Kim, Claudia Blattner, Alba Torrents de la Peña, Jacob Korzun, Michael Golabek, Kevin de los Reyes, Thomas J. Ketas, Marit J. van Gils, C. Richter King, Ian A. Wilson, Andrew B. Ward, P. J. Klasse, and John P. Moore. A Next-Generation Cleaved, Soluble HIV-1 Env Trimer, BG505 SOSIP.664 gp140, Expresses Multiple Epitopes for Broadly Neutralizing but not Non-Neutralizing Antibodies. PLoS Pathog., 9(9):e1003618, Sep 2013. PubMed ID: 24068931. Show all entries for this paper.

Sather2014 D. Noah Sather, Sara Carbonetti, Delphine C. Malherbe, Franco Pissani, Andrew B. Stuart, Ann J. Hessell, Mathew D. Gray, Iliyana Mikell, Spyros A. Kalams, Nancy L. Haigwood, and Leonidas Stamatatos. Emergence of Broadly Neutralizing Antibodies and Viral Coevolution in Two Subjects during the Early Stages of Infection with Human Immunodeficiency Virus Type 1. J. Virol., 88(22):12968-12981, Nov 2014. PubMed ID: 25122781. Show all entries for this paper.

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Shang2011 Hong Shang, Xiaoxu Han, Xuanling Shi, Teng Zuo, Mark Goldin, Dan Chen, Bing Han, Wei Sun, Hao Wu, Xinquan Wang, and Linqi Zhang. Genetic and Neutralization Sensitivity of Diverse HIV-1 env Clones from Chronically Infected Patients in China. J. Biol. Chem., 286(16):14531-14541, 22 Apr 2011. PubMed ID: 21325278. Show all entries for this paper.

Shivatare2013 Sachin S. Shivatare, Shih-Huang Chang, Tsung-I Tsai, Chien-Tai Ren, Hong-Yang Chuang, Li Hsu, Chih-Wei Lin, Shiou-Ting Li, Chung-Yi Wu, and Chi-Huey Wong. Efficient Convergent Synthesis of Bi-, Tri-, and Tetra-Antennary Complex Type N-Glycans and Their HIV-1 Antigenicity. J. Am. Chem. Soc., 135(41):15382-15391, 16 Oct 2013. PubMed ID: 24032650. Show all entries for this paper.

Sliepen2015 Kwinten Sliepen, Max Medina-Ramirez, Anila Yasmeen, John P. Moore, Per Johan Klasse, and Rogier W. Sanders. Binding of Inferred Germline Precursors of Broadly Neutralizing HIV-1 Antibodies to Native-Like Envelope Trimers. Virology, 486:116-120, Dec 2015. PubMed ID: 26433050. Show all entries for this paper.

Stewart-Jones2016 Guillaume B. E. Stewart-Jones, Cinque Soto, Thomas Lemmin, Gwo-Yu Chuang, Aliaksandr Druz, Rui Kong, Paul V. Thomas, Kshitij Wagh, Tongqing Zhou, Anna-Janina Behrens, Tatsiana Bylund, Chang W. Choi, Jack R. Davison, Ivelin S. Georgiev, M. Gordon Joyce, Young Do Kwon, Marie Pancera, Justin Taft, Yongping Yang, Baoshan Zhang, Sachin S. Shivatare, Vidya S. Shivatare, Chang-Chun D. Lee, Chung-Yi Wu, Carole A. Bewley, Dennis R. Burton, Wayne C. Koff, Mark Connors, Max Crispin, Ulrich Baxa, Bette T. Korber, Chi-Huey Wong, John R. Mascola, and Peter D. Kwong. Trimeric HIV-1-Env Structures Define Glycan Shields from Clades A, B, and G. Cell, 165(4):813-826, 5 May 2016. PubMed ID: 27114034. Show all entries for this paper.

Thenin2012 Suzie Thenin, Tanawan Samleerat, Elsa Tavernier, Nicole Ngo-Giang-Huong, Gonzague Jourdain, Marc Lallemant, Francis Barin, and Martine Braibant. Envelope Glycoproteins of Human Immunodeficiency Virus Type 1 Variants Issued from Mother-Infant Pairs Display a Wide Spectrum of Biological Properties. Virology, 426(1):12-21, 25 Apr 2012. PubMed ID: 22310702. Show all entries for this paper.

Thenin2012a Suzie Thenin, Emmanuelle Roch, Tanawan Samleerat, Thierry Moreau, Antoine Chaillon, Alain Moreau, Francis Barin, and Martine Braibant. Naturally Occurring Substitutions of Conserved Residues in Human Immunodeficiency Virus Type 1 Variants of Different Clades Are Involved in PG9 and PG16 Resistance to Neutralization. J. Gen. Virol., 93(7):1495-1505, Jul 2012. PubMed ID: 22492917. Show all entries for this paper.

Tomaras2010 Georgia D. Tomaras and Barton F. Haynes. Strategies for Eliciting HIV-1 Inhibitory Antibodies. Curr. Opin. HIV AIDS, 5(5):421-427, Sep 2010. PubMed ID: 20978384. Show all entries for this paper.

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Tong2012 Tommy Tong, Ema T. Crooks, Keiko Osawa, and James M. Binley. HIV-1 Virus-Like Particles Bearing Pure Env Trimers Expose Neutralizing Epitopes but Occlude Nonneutralizing Epitopes. J. Virol., 86(7):3574-3587, Apr 2012. PubMed ID: 22301141. Show all entries for this paper.

Upadhyay2014 Chitra Upadhyay, Luzia M. Mayr, Jing Zhang, Rajnish Kumar, Miroslaw K. Gorny, Arthur Nádas, Susan Zolla-Pazner, and Catarina E. Hioe. Distinct Mechanisms Regulate Exposure of Neutralizing Epitopes in the V2 and V3 Loops of HIV-1 Envelope. J. Virol., 88(21):12853-12865, Nov 2014. PubMed ID: 25165106. Show all entries for this paper.

vandenKerkhof2016 Tom L. G. M. van den Kerkhof, Steven W. de Taeye, Brigitte D. Boeser-Nunnink, Dennis R. Burton, Neeltje A. Kootstra, Hanneke Schuitemaker, Rogier W. Sanders, and Marit J. van Gils. HIV-1 escapes from N332-directed antibody neutralization in an elite neutralizer by envelope glycoprotein elongation and introduction of unusual disulfide bonds. Retrovirology, 13(1):48, 7 Jul 2016. PubMed ID: 27388013. Show all entries for this paper.

Veillette2014 Maxime Veillette, Anik Désormeaux, Halima Medjahed, Nour-Elhouda Gharsallah, Mathieu Coutu, Joshua Baalwa, Yongjun Guan, George Lewis, Guido Ferrari, Beatrice H. Hahn, Barton F. Haynes, James E. Robinson, Daniel E. Kaufmann, Mattia Bonsignori, Joseph Sodroski, and Andres Finzi. Interaction with Cellular CD4 Exposes HIV-1 Envelope Epitopes Targeted by Antibody-Dependent Cell-Mediated Cytotoxicity. J. Virol., 88(5):2633-2644, Mar 2014. PubMed ID: 24352444. Show all entries for this paper.

vonBredow2016 Benjamin von Bredow, Juan F. Arias, Lisa N. Heyer, Brian Moldt, Khoa Le, James E. Robinson, Susan Zolla-Pazner, Dennis R. Burton, and David T. Evans. Comparison of Antibody-Dependent Cell-Mediated Cytotoxicity and Virus Neutralization by HIV-1 Env-Specific Monoclonal Antibodies. J. Virol., 90(13):6127-6139, 1 Jul 2016. PubMed ID: 27122574. Show all entries for this paper.

Voss2017 James E. Voss, Raiees Andrabi, Laura E. McCoy, Natalia de Val, Roberta P. Fuller, Terrence Messmer, Ching-Yao Su, Devin Sok, Salar N. Khan, Fernando Garces, Laura K. Pritchard, Richard T. Wyatt, Andrew B. Ward, Max Crispin, Ian A. Wilson, and Dennis R. Burton. Elicitation of Neutralizing Antibodies Targeting the V2 Apex of the HIV Envelope Trimer in a Wild-Type Animal Model. Cell Rep., 21(1):222-235, 3 Oct 2017. PubMed ID: 28978475. Show all entries for this paper.

Voss2019 James E. Voss, Alicia Gonzalez-Martin, Raiees Andrabi, Roberta P. Fuller, Ben Murrell, Laura E. McCoy, Katelyn Porter, Deli Huang, Wenjuan Li, Devin Sok, Khoa Le, Bryan Briney, Morgan Chateau, Geoffrey Rogers, Lars Hangartner, Ann J. Feeney, David Nemazee, Paula Cannon, and Dennis R. Burton. Reprogramming the Antigen Specificity of B Cells Using Genome-Editing Technologies. eLife, 8, 17 Jan 2019. PubMed ID: 30648968. Show all entries for this paper.

Wagh2016 Kshitij Wagh, Tanmoy Bhattacharya, Carolyn Williamson, Alex Robles, Madeleine Bayne, Jetta Garrity, Michael Rist, Cecilia Rademeyer, Hyejin Yoon, Alan Lapedes, Hongmei Gao, Kelli Greene, Mark K. Louder, Rui Kong, Salim Abdool Karim, Dennis R. Burton, Dan H. Barouch, Michel C. Nussenzweig, John R. Mascola, Lynn Morris, David C. Montefiori, Bette Korber, and Michael S. Seaman. Optimal Combinations of Broadly Neutralizing Antibodies for Prevention and Treatment of HIV-1 Clade C Infection. PLoS Pathog., 12(3):e1005520, Mar 2016. PubMed ID: 27028935. Show all entries for this paper.

Walker2010 Laura M. Walker, Melissa D. Simek, Frances Priddy, Johannes S. Gach, Denise Wagner, Michael B. Zwick, Sanjay K. Phogat, Pascal Poignard, and Dennis R. Burton. A Limited Number of Antibody Specificities Mediate Broad and Potent Serum Neutralization in Selected HIV-1 Infected Individuals. PLoS Pathog., 6(8), 2010. PubMed ID: 20700449. Show all entries for this paper.

Walker2010a Laura M. Walker and Dennis R. Burton. Rational Antibody-Based HIV-1 Vaccine Design: Current Approaches and Future Directions. Curr. Opin. Immunol., 22(3):358-366, Jun 2010. PubMed ID: 20299194. Show all entries for this paper.

Walker2011 Laura M. Walker, Michael Huber, Katie J. Doores, Emilia Falkowska, Robert Pejchal, Jean-Philippe Julien, Sheng-Kai Wang, Alejandra Ramos, Po-Ying Chan-Hui, Matthew Moyle, Jennifer L. Mitcham, Phillip W. Hammond, Ole A. Olsen, Pham Phung, Steven Fling, Chi-Huey Wong, Sanjay Phogat, Terri Wrin, Melissa D. Simek, Protocol G. Principal Investigators, Wayne C. Koff, Ian A. Wilson, Dennis R. Burton, and Pascal Poignard. Broad Neutralization Coverage of HIV by Multiple Highly Potent Antibodies. Nature, 477(7365):466-470, 22 Sep 2011. PubMed ID: 21849977. Show all entries for this paper.

Walker2018 Laura M. Walker and Dennis R. Burton. Passive Immunotherapy of Viral Infections: `Super-Antibodies' Enter the Fray. Nat. Rev. Immunol., 18(5):297-308, May 2018. PubMed ID: 29379211. Show all entries for this paper.

Wang2013 Wenbo Wang, Jianhui Nie, Courtney Prochnow, Carolyn Truong, Zheng Jia, Suting Wang, Xiaojiang S. Chen, and Youchun Wang. A Systematic Study of the N-Glycosylation Sites of HIV-1 Envelope Protein on Infectivity and Antibody-Mediated Neutralization. Retrovirology, 10:14, 2013. PubMed ID: 23384254. Show all entries for this paper.

Wang2018a Hongye Wang, Ting Yuan, Tingting Li, Yanpeng Li, Feng Qian, Chuanwu Zhu, Shujia Liang, Daniel Hoffmann, Ulf Dittmer, Binlian Sun, and Rongge Yang. Evaluation of Susceptibility of HIV-1 CRF01\_AE Variants to Neutralization by a Panel of Broadly Neutralizing Antibodies. Arch. Virol., 163(12):3303-3315, Dec 2018. PubMed ID: 30196320. Show all entries for this paper.

Webb2015 Nicholas E. Webb, David C. Montefiori, and Benhur Lee. Dose-Response Curve Slope Helps Predict Therapeutic Potency and Breadth of HIV Broadly Neutralizing Antibodies. Nat. Commun., 6:8443, 29 Sep 2015. PubMed ID: 26416571. Show all entries for this paper.

Wen2018 Yingxia Wen, Hung V. Trinh, Christine E Linton, Chiara Tani, Nathalie Norais, DeeAnn Martinez-Guzman, Priyanka Ramesh, Yide Sun, Frank Situ, Selen Karaca-Griffin, Christopher Hamlin, Sayali Onkar, Sai Tian, Susan Hilt, Padma Malyala, Rushit Lodaya, Ning Li, Gillis Otten, Giuseppe Palladino, Kristian Friedrich, Yukti Aggarwal, Celia LaBranche, Ryan Duffy, Xiaoying Shen, Georgia D. Tomaras, David C. Montefiori, William Fulp, Raphael Gottardo, Brian Burke, Jeffrey B. Ulmer, Susan Zolla-Pazner, Hua-Xin Liao, Barton F. Haynes, Nelson L. Michael, Jerome H. Kim, Mangala Rao, Robert J. O'Connell, Andrea Carfi, and Susan W. Barnett. Generation and Characterization of a Bivalent Protein Boost for Future Clinical Trials: HIV-1 Subtypes CR01\_AE and B gp120 Antigens with a Potent Adjuvant. PLoS One, 13(4):e0194266, 2018. PubMed ID: 29698406. Show all entries for this paper.

West2012 Anthony P. West, Jr., Rachel P. Galimidi, Priyanthi N. P. Gnanapragasam, and Pamela J. Bjorkman. Single-Chain Fv-Based Anti-HIV Proteins: Potential and Limitations. J. Virol., 86(1):195-202, Jan 2012. PubMed ID: 22013046. Show all entries for this paper.

West2013 Anthony P. West, Jr., Louise Scharf, Joshua Horwitz, Florian Klein, Michel C. Nussenzweig, and Pamela J. Bjorkman. Computational Analysis of Anti-HIV-1 Antibody Neutralization Panel Data to Identify Potential Functional Epitope Residues. Proc. Natl. Acad. Sci. U.S.A., 110(26):10598-10603, 25 Jun 2013. PubMed ID: 23754383. Show all entries for this paper.

Wibmer2013 Constantinos Kurt Wibmer, Jinal N. Bhiman, Elin S Gray, Nancy Tumba, Salim S. Abdool Karim, Carolyn Williamson, Lynn Morris, and Penny L. Moore. Viral Escape from HIV-1 Neutralizing Antibodies Drives Increased Plasma Neutralization Breadth through Sequential Recognition of Multiple Epitopes and Immunotypes. PLoS Pathog, 9(10):e1003738, Oct 2013. PubMed ID: 24204277. Show all entries for this paper.

Wilen2011 Craig B. Wilen, Nicholas F. Parrish, Jennifer M. Pfaff, Julie M. Decker, Elizabeth A. Henning, Hillel Haim, Josiah E. Petersen, Jason A. Wojcechowskyj, Joseph Sodroski, Barton F. Haynes, David C. Montefiori, John C. Tilton, George M. Shaw, Beatrice H. Hahn, and Robert W. Doms. Phenotypic and Immunologic Comparison of Clade B Transmitted/Founder and Chronic HIV-1 Envelope Glycoproteins. J Virol, 85(17):8514-8527, Sep 2011. PubMed ID: 21715507. Show all entries for this paper.

Willis2016 Jordan R. Willis, Jessica A. Finn, Bryan Briney, Gopal Sapparapu, Vidisha Singh, Hannah King, Celia C. LaBranche, David C. Montefiori, Jens Meiler, and James E. Crowe, Jr. Long Antibody HCDR3s from HIV-Naive Donors Presented on a PG9 Neutralizing Antibody Background Mediate HIV Neutralization. Proc. Natl. Acad. Sci. U.S.A., 113(16):4446-4451, 19 Apr 2016. PubMed ID: 27044078. Show all entries for this paper.

Wu2011a Xueling Wu, Anita Changela, Sijy O'Dell, Stephen D. Schmidt, Marie Pancera, Yongping Yang, Baoshan Zhang, Miroslaw K. Gorny, Sanjay Phogat, James E. Robinson, Leonidas Stamatatos, Susan Zolla-Pazner, Peter D. Kwong, and John R. Mascola. Immunotypes of a Quaternary Site of HIV-1 Vulnerability and Their Recognition by Antibodies. J. Virol., 85(9):4578-4585, May 2011. PubMed ID: 21325411. Show all entries for this paper.

Wu2016 Xueling Wu and Xiang-Peng Kong. Antigenic Landscape of the HIV-1 Envelope and New Immunological Concepts Defined by HIV-1 Broadly Neutralizing Antibodies. Curr. Opin. Immunol., 42:56-64, Oct 2016. PubMed ID: 27289425. Show all entries for this paper.

Wu2018 Xilin Wu, Jia Guo, Mengyue Niu, Minghui An, Li Liu, Hui Wang, Xia Jin, Qi Zhang, Ka Shing Lam, Tongjin Wu, Hua Wang, Qian Wang, Yanhua Du, Jingjing Li, Lin Cheng, Hang Ying Tang, Hong Shang, Linqi Zhang, Paul Zhou, and Zhiwei Chen. Tandem bispecific neutralizing antibody eliminates HIV-1 infection in humanized mice. J Clin Invest, 128(6):2239-2251, Jun 1 2018. PubMed ID: 29461979. Show all entries for this paper.

Yang2014 Lili Yang and Pin Wang. Passive Immunization against HIV/AIDS by Antibody Gene Transfer. Viruses, 6(2):428-447, Feb 2014. PubMed ID: 24473340. Show all entries for this paper.

Yasmeen2014 Anila Yasmeen, Rajesh Ringe, Ronald Derking, Albert Cupo, Jean-Philippe Julien, Dennis R. Burton, Andrew B. Ward, Ian A. Wilson, Rogier W. Sanders, John P. Moore, and Per Johan Klasse. Differential Binding of Neutralizing and Non-Neutralizing Antibodies to Native-Like Soluble HIV-1 Env Trimers, Uncleaved Env Proteins, and Monomeric Subunits. Retrovirology, 11:41, 2014. PubMed ID: 24884783. Show all entries for this paper.

Yates2018 Nicole L. Yates, Allan C. deCamp, Bette T. Korber, Hua-Xin Liao, Carmela Irene, Abraham Pinter, James Peacock, Linda J. Harris, Sheetal Sawant, Peter Hraber, Xiaoying Shen, Supachai Rerks-Ngarm, Punnee Pitisuttithum, Sorachai Nitayapan, Phillip W. Berman, Merlin L. Robb, Giuseppe Pantaleo, Susan Zolla-Pazner, Barton F. Haynes, S. Munir Alam, David C. Montefiori, and Georgia D. Tomaras. HIV-1 Envelope Glycoproteins from Diverse Clades Differentiate Antibody Responses and Durability among Vaccinees. J. Virol., 92(8), 15 Apr 2018. PubMed ID: 29386288. Show all entries for this paper.

Zhang2013 Yu Zhang, Tingting Yuan, Jingjing Li, Yanyu Zhang, Jianqing Xu, Yiming Shao, Zhiwei Chen, and Mei-Yun Zhang. The Potential of the Human Immune System to Develop Broadly Neutralizing HIV-1 Antibodies: Implications for Vaccine Development. AIDS, 27(16):2529-2539, 23 Oct 2013. PubMed ID: 24100711. Show all entries for this paper.

Zhou2014 Jing Zhou, Ning Gan, Tianhua Li, Futao Hu, Xing Li, Lihong Wang, and Lei Zheng. A Cost-Effective Sandwich Electrochemiluminescence Immunosensor for Ultrasensitive Detection of HIV-1 Antibody Using Magnetic Molecularly Imprinted Polymers as Capture Probes. Biosens. Bioelectron., 54:199-206, 15 Apr 2014. PubMed ID: 24280050. Show all entries for this paper.

Zhou2017 Tongqing Zhou, Nicole A. Doria-Rose, Cheng Cheng, Guillaume B. E. Stewart-Jones, Gwo-Yu Chuang, Michael Chambers, Aliaksandr Druz, Hui Geng, Krisha McKee, Young Do Kwon, Sijy O'Dell, Mallika Sastry, Stephen D. Schmidt, Kai Xu, Lei Chen, Rita E. Chen, Mark K. Louder, Marie Pancera, Timothy G. Wanninger, Baoshan Zhang, Anqi Zheng, S. Katie Farney, Kathryn E. Foulds, Ivelin S. Georgiev, M. Gordon Joyce, Thomas Lemmin, Sandeep Narpala, Reda Rawi, Cinque Soto, John-Paul Todd, Chen-Hsiang Shen, Yaroslav Tsybovsky, Yongping Yang, Peng Zhao, Barton F. Haynes, Leonidas Stamatatos, Michael Tiemeyer, Lance Wells, Diana G. Scorpio, Lawrence Shapiro, Adrian B. McDermott, John R. Mascola, and Peter D. Kwong. Quantification of the Impact of the HIV-1-Glycan Shield on Antibody Elicitation. Cell Rep., 19(4):719-732, 25 Apr 2017. PubMed ID: 28445724. Show all entries for this paper.

Wu2011 Xueling Wu, Tongqing Zhou, Jiang Zhu, Baoshan Zhang, Ivelin Georgiev, Charlene Wang, Xuejun Chen, Nancy S. Longo, Mark Louder, Krisha McKee, Sijy O'Dell, Stephen Perfetto, Stephen D. Schmidt, Wei Shi, Lan Wu, Yongping Yang, Zhi-Yong Yang, Zhongjia Yang, Zhenhai Zhang, Mattia Bonsignori, John A. Crump, Saidi H. Kapiga, Noel E. Sam, Barton F. Haynes, Melissa Simek, Dennis R. Burton, Wayne C. Koff, Nicole A. Doria-Rose, Mark Connors, NISC Comparative Sequencing Program, James C. Mullikin, Gary J. Nabel, Mario Roederer, Lawrence Shapiro, Peter D. Kwong, and John R. Mascola. Focused Evolution of HIV-1 Neutralizing Antibodies Revealed by Structures and Deep Sequencing. Science, 333(6049):1593-1602, 16 Sep 2011. PubMed ID: 21835983. Show all entries for this paper.

Displaying record number 658

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MAb ID	17b (1.7b, sCD4-17b, 1.7B)
HXB2 Location	Env	Env Epitope Map
Author Location	gp120
Research Contact	James Robinson, Tulane University, New Orleans, LA, USA
Epitope	(Discontinuous epitope)
Ab Type	gp120 CD4i CoRBS (Cluster C)
Neutralizing	L P (weak) View neutralization details
Contacts and Features	View contacts and features
Species (Isotype)	human
Patient	N70
Immunogen	HIV-1 infection
Keywords	acute/early infection, ADCC, adjuvant comparison, antibody binding site, antibody generation, antibody interactions, antibody lineage, antibody polyreactivity, antibody sequence, assay or method development, autoantibody or autoimmunity, autologous responses, binding affinity, brain/CSF, broad neutralizer, co-receptor, computational epitope prediction, dendritic cells, drug resistance, dynamics, enhancing activity, escape, glycosylation, HAART, ART, immunoprophylaxis, immunotherapy, kinetics, mimics, mimotopes, neutralization, polyclonal antibodies, review, structure, subtype comparisons, vaccine antigen design, vaccine-induced immune responses, variant cross-reactivity, viral fitness and reversion

Notes

Showing 270 of 270 notes.

17b: Single chain variable fragments (scFvs) were constructed for mAbs 916B2, 4E9C, and 25C4b. Coverage of neutralization by the scFvs against a panel of 66 multiclade pseudoviruses was 89% for 4E9C, 95% for 25C4b, and 100% for 916B2. 25C4b bound the region spanning multiple domains of hairpin 1 (H1) and H2 of the bridging sheet and V3 base, similar to mAb 17b. For 4E9C, V3-base dependent binding was apparent based on lack of binding to mutants containing a V3 truncation. In contrast, binding of 916B2 was dependent on the H1 region. The study also assayed the binding of additional mAbs (17b, 12G10, 917B11, 5D6S, A32) to gp120 mutants in the CD4i region. Tanaka2017 (antibody binding site)
17b: The study compared well-characterized nAbs (2G12, b12, VRC01, 10E8, 17b) with 4 mAbs derived from a Japanese patient (4E9C, 49G2, 916B2, 917B11), in their neutralization and ADCC activity against viruses of subtypes B and CRF01. CRF01 viruses were less susceptible to neutralization by 2G12 and b12, while VRC01 was highly effective in neutralizing CRF01 viruses. 49G2 showed better neutralization breadth against CRF01 than against B viruses. CRF01_AE viruses from Japan also showed a slightly higher susceptibility to anti-CD4i Ab 4E9C than the subtype B viruses, and to CRF01_AE viruses from Vietnam. Neutralization breadth of other anti-CD4i Abs 17b, 916B2 and 917B11 was low against both subtype B and CRF01_AE viruses. Anti-CD4bs Ab 49G2, which neutralized only 22% of the viruses, showed the broadest coverage of Fc-mediated signaling activity against the same panel of Env clones among the Abs tested. The CRF01_AE viruses from Japan were more susceptible to 49G2-mediated neutralization than the CRF01_AE viruses from Vietnam, but Fc-mediated signaling activity of 49G2was broader and stronger in the CRF01_AE viruses from Vietnam than the CRF01_AE viruses from Japan. Thida2019 (ADCC, neutralization, subtype comparisons)
17b: An R5 virus isolated from chronic patient NAB01 (Patient Record# 4723) was adapted in culture to growth in the presence of target cells expressing reduced levels of CD4. Entry kinetics of the virus were altered, and these alterations resulted in extended exposure of CD4-induced neutralization-sensitive epitopes to CD4. Adapted and control viruses were assayed for their neutralization by a panel of neutralizing antibodies targeting several different regions of Env (PGT121, PGT128, 1-79, 447-52d, b6, b12, VRC01, 17b, 4E10, 2F5, Z13e1). Adapted viruses showed greater sensitivity to antibodies targeting the CD4 binding site and the V3 loop. This evolution of Env resulted in increased CD4 affinity but decreased viral fitness, a phenomenon seen also in the immune-privileged CNS, particularly in macrophages. Beauparlant2017 (neutralization, viral fitness and reversion, dynamics, kinetics)
17b: Soluble versions of HIV-1 Env trimers (sgp140 SOSIP.664) stabilized by a gp120-gp41 disulfide bond and a change (I559P) in gp41 have been structurally characterized. Cross-linking/mass spectrometry to evaluate the conformations of functional membrane Env and sgp140 SOSIP.664 has been reported. Differences were detected in the gp120 trimer association domain and C terminus and in the gp41 HR1 region which can guide the improvement of Env glycoprotein preparations and potentially increasing their effectiveness as a vaccine. The CD4i Ab 17b exhibited poor neutralization against HIV-1AD8 full-length and cytoplasmic tail-deleted Envs. Castillo-Menendez2019 (vaccine antigen design, structure)
17b: The authors used nuclear magnetic resonance (NMR) to define the structure of the HIV-1 MPER when linked to the transmembrane domain (MPER-TMD) in the context of a lipid bilayer. In particular, they looked at the accessibility of the MPER-TMD to 2F5, 4E10, 10E8 and DH570. The MPER appears to be accessible up to ∼10% of the time to the 2F5, 4E10, and 10E8 Fabs but ∼40% of time to the DH570 Fab. To assess possible functional roles for the MPER in membrane fusion, they generated 17 Env mutants using the sequence of a clade A isolate, 92UG037.8, mutating each of the three structural elements: hydrophobic core, turn, and kink. Mutants W670A (hydrophobic core), F673A (turn), and W680A (kink), while still sensitive to VRC01, became much more resistant to the trimer-specific bNAbs and also gained sensitivity to b6, 3791, and 17b. All mutants with changes at W666 in the hydrophobic core and K683 at the kink lost infectivity almost completely. For the rest of the mutants, infectivity ranged from 4.3 to 50.8% of that of the wild type, showing that key residues important for stabilizing the MPER structure are also critical for Env-induced membrane fusion activity, especially in the context of viral infection. Fu2018 (antibody binding site, antibody interactions, neutralization, variant cross-reactivity, binding affinity, structure)
17b: The influence of a V2 State 2/3-stabilizing Env mutation, L193A, on ADCC responses mediated by sera from HIV-1-infected individuals was evaluated. Conformations spontaneously sampled by the Env trimer at the surface of infected cells had a significant impact on ADCC. State 2/3 preferring ligand 17b recognized L193A variants of CH58 and CH77 IMCs with a significant increase compared to the WT. Prevost2018 (ADCC)
17b: The first cryo-EM structure of a cross-linked vaccine antigen was solved. The 4.2 Å structure of HIV-1 BG505 SOSIP soluble recombinant Env in complex with a bNAb PGV04 Fab fragment revealed how cross-linking affects key properties of the trimer. ISOSIP and GLA-SOSIP trimers were compared for antigenicity by ELISA, using a large panel of mAbs previously determined to react with BG505 Env. Non-NAbs globally lost reactivity (7-fold median loss of binding), likely because of covalent stabilization of the cross-linked ‘closed’ form of the GLA-SOSIP trimer that binds non-NAbs weakly or not at all. V3-specific non-NAbs showed 2.1–3.3-fold reduced binding. Three autologous rabbit monoclonal NAbs to the N241/N289 ‘glycan-hole’ surface, showed a median ˜1.5-fold reduction in binding. V3 non-NAb 4025 showed residual binding to the GLA-SOSIP trimer. By contrast, bNAbs like 17b broadly retained reactivity significantly better than non-NAbs, with exception of PGT145 (3.3-5.3 fold loss of binding in ELISA and SPR). Schiffner2018 (vaccine antigen design, binding affinity, structure)
17b: This study describes the generation of CHO cell lines stably expressing the following vaccine Env Ags: CRF01_AE A244 Env gp120 protein (A244.AE) and 6240 Env gp120 protein (6240.B). The antigenic profiles of the molecules were assessed with a panel of well-characterized mAbs recognizing critical epitopes and glycosylation analysis confirming previously identified sites and revealing unknown sites at non-consensus motifs.A244.AE gp120 showed low level of binding to 17b in ELISA EC50 and Surface Plasmon Resonance (SPR) assays. 6240.B gp120 exhibited binding to 17b. Wen2018 (glycosylation, vaccine antigen design)
17b: Assays of poly- and autoreactivity demonstrated that broadly neutralizing NAbs are significantly more poly- and autoreactive than non-neutralizing NAbs. 17b is neither autoreactive nor polyreactive. Liu2015a (autoantibody or autoimmunity, antibody polyreactivity)
17B: The study identified a HIV-1–neutralizing protein in breast milk, Tenascin-C (TNC). TNC is an extracellular matrix protein important in fetal development and wound healing. TNC bound the HIV-1 Envelope protein at a site that is induced upon engagement of its primary receptor, CD4, and is blocked by monoclonal antibodies that bind to the V3 loop (19B and F39F) and chemokine coreceptor binding site (17B). Fouda2013 (antibody binding site)
17b: The immunologic effects of mutations in the Env cytoplasmic tail (CT) that included increased surface expression were explored using a vaccinia prime/protein boost protocol in mice. After vaccinia primes, CT- modified Envs induced up to 7-fold higher gp120-specific IgG, and after gp120 protein boosts, they elicited up to 16-fold greater Tier-1 HIV-1 neutralizing antibody titers. Envs with or without the TM1 mutations were expressed in HEK 293T cells and analyzed for the relative expression of Ab epitopes including the co-receptor binding site for 17b. Hogan2018 (vaccine antigen design)
17b: SOSIP.664 trimer was modified at V3 positions 306 and 308 by Leucine substitution to create hydrophobic interactions with the tryptophan residue at position 316 and the V1V2 domain. These modifications stabilized the resulting SOSIP.v5.2 S306L R308L trimers. In vivo, the induction of V3 non-NAbs was significantly reduced compared with the SOSIP.v5.2 trimers. deTaeye2018 (broad neutralizer)
17b: Nanodiscs (discoidal lipid bilayer particles of 10-17 nm surrounded by membrane scaffold protein) were used to incorporate Env complexes for the purpose of vaccine platform generation. The Env-NDs (Env-NDs) were characterized for antigenicity and stability by non-NAbs and NAbs. Most NAb epitopes in gp41 MPER and in the gp120:gp41 interface were well exposed while non-NAb cell surface epitopes were generally masked. Anti-gp120 non-NAb 17b, binds at a fraction of the binding of 2G12 to Env-ND, and this binding is slightly sensitive to glutaraldehyde treatment . Witt2017 (vaccine antigen design, binding affinity)
17b: Three strategies were applied to perturb the structure of Env in order to make the protein more susceptible to neutralization: exposure to cold, Env-activating ligands, and a chaotropic agent. A panel of mAbs (E51, 48d, 17b, 3BNC176, 19b, 447-52D, 39F, b12, b6, PG16, PGT145, PGT126, 35O22, F240, 10E8, 7b2, 2G12) was used to test the neutralization resistance of a panel of subtype B and C pseudoviruses with and without these agents. Both cold and CD4 mimicking agents (CD4Ms) increased the sensitivity of some viruses. The chaotropic agent urea had little effect by itself, but could enhance the effects of cold or CD4Ms. Thus Env destabilizing agents can make Env more susceptible to neutralization and may hold promise as priming vaccine antigens. Johnson2017 (vaccine antigen design)
17b: Env from of a highly neutralization-resistant isolate, CH120.6, was shown to be very stable and conformationally-homogeneous. Its gp140 trimer retains many antigenic properties of the intact Env, while its monomeric gp120 exposes more epitopes. Thus trimer organization and stability are important determinants for occluding epitopes and conferring resistance to antibodies. Among a panel of 21 mAbs, CH120.6 was resistant to neutralization by all non-neutralizing and strain-specific mAbs (including 17b), regardless of the location of their epitopes. It was weakly neutralized by several broadly-neutralizing mAbs (VRC01, NIH45-46, 12A12, PG9, PG16, PGT128, 4E10, and 10E8), and well neutralized by only 2 (PGT145 and 10-1074). Cai2017 (neutralization)
17b: Compared to patient-derived mAbs, vaccine-elicited mAbs are often less able to neutralize the virus, due to a less-effective angle of approach to the Env spike. This study engineered an immunogen consisting of the gp120 core in complex with a CD4bs mAb, 17b. Rabbits immunized with this antigen displayed earlier affinity maturation and better virus neutralization compared to those immunized with the gp120 core alone. The 17b antibody was shown to have a steric clash with two other CD4bs Abs, GE136 and GE148, but not with VRC01. Chen2016b (antibody binding site, vaccine antigen design, vaccine-induced immune responses, structure)
17b: The amino acid at gp120 position 375 is embedded in the Phe43 cavity, which affects susceptibility to ADCC. Most M-group strains of HIV-1 have serine at position 375, but CRF01 typically has histidine, which is a bulky residue. MAbs 2G12 and 10E8 were not affected by changes in residue 375, while recognition by CD4i mAbs 17b and A32 was increased by mutations of residue 375 to histidine or tryptophan. Participants in the AIDSVAX vaccine trial were infected by CRF01, and a significant part of the efficacy of this vaccine rested on ADCC responses. The ADCC response of MAbs derived from AIDSVAX participants (CH29, CH38, CH40, CH51, CH52, CH54, CH77, CH80, CH81, CH89, CH91, CH94) was dependent on the presence of 375H and greatly decreased by the presence of 375S. Prevost2017 (ADCC, vaccine-induced immune responses)
17b: The results confirm that Nef and Vpu protect HIV-1-infected cells from ADCC, but also show that not all classes of antibody can mediate ADCC. Anti-cluster-A antibodies are able to mediate potent ADCC responses, whereas anti-coreceptor binding site antibodies are not. Position 69 in gp120 is important for antibody-mediated cellular toxicity by anti-cluster-A antibodies. The angle of approach of a given class of antibodies could impact its capacity to mediate ADCC. Mabs 17b and LF17 were used as anti-CoRBS Abs. Ding2015 (ADCC)
17b: To understand HIV neutralization mediated by the MPER, antibodies and viruses were studied from CAP206, a patient known to produce MPER-targeted neutralizing mAbs. 41 human mAbs were isolated from CAP206 at various timepoints after infection, and 4 macaque mAbs were isolated from animals immunized with CAP206 Env proteins. Two rare, naturally-occuring single-residue changes in Env were identified in transmitted/founder viruses (W680G in CAP206 T/F and Y681D in CH505 T/F) that made the viruses less resistant to neutralization. The results point to the role of the MPER in mediating the closed trimer state, and hence the neutralization resistance of HIV. CH58 was one of several mAbs tested for neutralization of transmitted founder viruses isolated from clade C infected individuals CAP206 and CH505, compared to T/F viruses containing MPER mutations that confer enhanced neutralization sensitivity. Bradley2016a (neutralization)
17b: 15e: This study investigated the ability of native, membrane-expressed JR-FL Env trimers to elicit NAbs. Rabbits were immunized with virus-like particles (VLPs) expressing trimers (trimer VLP sera) and DNA expressing native Env trimer, followed by a protein boost (DNA trimer sera). N197 glycan- and residue 230- removal conferred sensitivity to Trimer VLP sera and DNA trimer sera respectively, showing for the first time that strain-specific holes in the "glycan fence" can allow the development of tier 2 NAbs to native spikes. All 3 sera neutralized via quaternary epitopes and exploited natural gaps in the glycan defenses of the second conserved region of JR-FL gp120. N197 glycan mutants were tested against 17b showing a loss of tier 2 phenotype. The results are in Table S5. Crooks2015 (glycosylation, neutralization)
17b: Env residue N197 on the BG505-SOSIP trimer was mutated to test the effect of its glycosylation on the binding kinetics of CD4BS and other mAbs. Removal of the glycan had little effect on the overall structure of the molecule. Its removal resulted in increased binding of CD4 and CD4BS antibodies (VRC01, VRC03, V3-3074), but little effect on bNAbs targeting other epitopes (PG9, PG16, PGT145, 17b, A32, 2G12, PGT121, PGT126). Two CD4BS-binding antibodies tested (b12, F105) had insufficient breadth to bind the BG505-SOSIP trimer. Removal of the N197 glycan may allow for the development of better SOSIP immunogens, particularly to elicit CD4BS-specific Abs. Liang2016
17b: This study assessed the ADCC activity of antibodies of varied binding types, including CD4bs (b6, b12, VRC01, PGV04, 3BNC117), V2 (PG9, PG16), V3 (PGT126, PGT121, 10-1074), oligomannose (2G12), MPER (2F5, 4E10, 10E8), CD4i (17b, X5), C1/C5 (A32, C11), cluster I (240D, F240), and cluster II (98-6, 126-7). ADCC activity was correlated with binding to Env on the surfaces of virus-infected cells. ADCC was correlated with neutralization, but not always for lab-adapted viruses such as HIV-1 NLA-3. vonBredow2016 (ADCC)
17b: Two stable homogenous gp140 Env trimer spikes, Clade A 92UG037.8 Env and Clade C C97ZA012 Env, were identified. 293T cells stably transfected with either presented fully functional surface timers, 50% of which were uncleaved. A panel of neutralizing and non-neutralizing Abs were tested for binding to the trimers. Non-neutralizing CD4i Ab, 17b did not bind cell surface or neutralize 92UG037.8 HIV-1 isolate, but it did bind well in the presence of sCD4. Chen2015 (neutralization, binding affinity)
17b: PGT145 was used to positively isolate a subtype B Env trimer immunogen, B41 SOSIP.664, that exists in two conformations, closed and partially open. bNAbs tested against the trimer were able to neutralize the B41 pseudovirus with a wide range of potencies. Among non-NAbs to CD4bs (b6, F91, F105); to CD4i (17b); to gp41_ECTO (F240); and to V3 (447-52D, 39F, CO11, 19b and 14e), none neutralized B41 (IC₅₀ >50µg/ml). Pugach2015
17b: A comprehensive antigenic map of the cleaved trimer BG505 SOSIP.664 was made by bNAb cross-competition. Epitope clusters at the CD4bs, quaternary V1/V2 glycan, N332-oligomannose patch and new gp120-gp41 interface and their interactions were delineated. Epitope overlap, proximal steric inhibition, allosteric inhibition or reorientation of glycans were seen in Ab cross-competition. Thus bNAb binding to trimers can affect surfaces beyond their epitopes. CD4i non-NAb, 17b binding was modestly increased by the initial binding of CD4bs bNAbs, VRC01, 3BNC60, NIH45-46. Derking2015 (antibody interactions, neutralization, binding affinity, structure)
17b: Two clade C recombinant Env glycoprotein trimers, DU422 and ZM197M, with native-like structural and antigenic properties involving epitopes against all known classes of bNAbs, were produced and characterized. These Clade C trimers (10-15% of which are in a partially open form) were more like B41 Clade B trimers which have 50-75% trimers in the partially open configuration than like B505 Clade B trimers, almost 100% in the closed, prefusion state. The Clade C trimers have almost no affinity for the CD4induced non-NAb, 17b, and 17b was unable to neutralize the equivalent pseudotyped viruses for either trimer. Julien2015 (assay or method development, structure)
17b: Env trimer BG505 SOSIP.664 as well as the clade B trimer B41 SOSIP.664 were stabilized using a bifunctional aldehyde (glutaraldehye, GLA) or a heterobifunctional cross-linker, EDC/NHS with modest effects on antigenicity and barely any on biochemistry or structural morphology. ELISA, DSC and SPR were used to test recognition of the trimers by bNAbs, which was preserved and by weakly NAbs or non-NAbs, which was reduced. Cross-linking partially preserves quaternary morphology so that affinity chromatography by positive selection using quaternary epitope-specific bNAabs, and negative selection using non-NAbs, enriched antigenic characteristics of the trimers. Binding of CD4i-epitope-recognizing non-NAb, 19b, to trimers was almost completely eliminated by trimer cross-linking. Schiffner2016 (assay or method development, binding affinity, structure)
17b: A new trimeric immunogen, BG505 SOSIP.664 gp140, was developed that bound and activated most known neutralizing antibodies but generally did not bind antibodies lacking neuralizing activity. This highly stable immunogen mimics the Env spike of subtype A transmitted/founder (T/F) HIV-1 strain, BG505. Anti-CDi non-NAb 17b did not neutralize BG505.T332N, the pseudoviral equivalent of the immunogen BG505 SOSIP.664 gp140, and did not recognize or bind the immunogen either. Sanders2013 (assay or method development, neutralization, binding affinity)
17b: A panel of Env-specific mAbs was isolated from 6 HIV1-infected lactating women. Antibodies in colostrum may help prevent mucosal infection of the infant, so this study aimed to define milk IgGs for future vaccination strategies to reduce HIV transmission during lactation. Despite the high rate of VH 1-69 usage among colostrum Env specific B cells, it did not correlate with distinct gp120 epitope specificity or function. 17b was compared to the newly-derived mAbs; it didn't cross-react with gut bacteria, and tested negative in 2 tests of autoreactivity. Jeffries2016 (antibody polyreactivity)
17b: A solution-phase ECL assay for ultrasensitive and quantitative analysis of binding affinities of HIV receptor and MAb interactions has been demonstrated. This study of binding of gp120 with anti CD4 mAb Q4120-CD4-tag and 17b-gp120 with CD4-tag shows that Q4120 can completely block the binding of gp120 with CD4-tag, while 17b can only partially block their binding. The results indicate that Q4120 can serve as a more effective neutralizing antibody than 17b to potentially block the HIV infection of T cells. Xu2013 (antibody interactions, assay or method development)
17B: Galactosyl ceramide (Galcer), a glycosphingolipid, is a receptor for the HIV-1 Env glycoprotein. This study has mimicked this interaction by using an artificial membrane containing synthetic Galcer and recombinant HIV-1 Env proteins to identify antibodies that would block the HIV-1 Env-Galcer interaction. HIV-1 ALVAC/AIDSVAX vaccinee-derived MAbs specific for the gp120 C1 region blocked Galcer binding of a transmitted/founder HIV-1 Env gp140. MAb 17B itself did not block Env-Galcer binding, suggesting that the C1 Ab-induced gp120 conformational changes resulted in alteration in a Galcer binding site distant from the CD4i 17B MAb binding site. Dennison2014 (ADCC, antibody binding site, antibody interactions, glycosylation)
17b: 17b was one of 10 MAbs used to study chronic vs. consensus vs. transmitted/founder (T/F) gp41 Envs for immunogenicity. Consensus Envs were the most potent eliciters of response but could only neutralize tier 1 and some tier 2 viruses. T/F Envs elicited the greatest breadth of NAb response; and chronic Envs elicited the lowest level and narrowest response. This CCR5BS binding Nab bound well at <10 nM to 3/5 chronic Envs, 3/6 Consensus Envs and 6/7 T/F Envs. Liao2013c (antibody interactions, binding affinity)
17b: The neutralization profile of 1F7, a human CD4bs mAb, is reported and compared to other bnNAbs. 1F7 competed with 17b for binding with gp120. Gach2013 (neutralization)
17b: This study reported the Ab binding titers and neutralization of 51 patients with chronic HIV-1 infection on supressive ART for 3 yrs. A high titer of Ab against gp120, gp41, and MPER was found. Patient sera were evaluated for binding against recombinant gp120_JR-FL mutants lacking either the V1/V2 loop or the V3 loop. Significantly higher end point binding titers and HIV1_JR-FL neutralization were noticed in patients with >10 compared to <10 yrs of detectable HIV RNA. 17b was used as a CD4b Ab control. Gach2014 (neutralization, HAART, ART)
17b: A highly conserved mechanism of exposure of ADCC epitopes on Env is reported, showing that binding of Env and CD4 within the same HIV-1 infected cell effectively exposes these epitopes. The mechanism might explain the evolutionary advantage of downregulation of cell surface CD4v by the Vpu and Nef proteins. 17b was used in co-expression and cryoelectron tomography assays to understand the conformational changes in Env upon CD4 binding. Veillette2014 (ADCC, structure)
17b: The ability of MAb A32 to recognize HIV-1 Env expressed on the surface of infected CD4(+) T cells as well as its ability to mediate antibody-dependent cellular cytotoxicity (ADCC) activity was investigated. This study demonstrates that the epitope defined by MAb A32 is a major target on gp120 for plasma ADCC activity. 17b was used as a control and A32 showed 4-6 fold higher ADCC activity than 17b. Ferrari2011a (ADCC)
17b:X-ray crystallography, surface plasmon resonance and pseudovirus neutralization were used to characterize a heavy chain only llama antibody, named JM4. The full-length IgG2b version of JM4 neutralizes over 95% of circulating HIV-1 isolates. JM4 targets a hybrid epitope on gp120 that combines elements from both the CD4 binding region and the coreceptor binding surface. JM4 epitope overlaps with the CD4i binding site of 17b. Acharya2013 (neutralization)
17b: A computational method to predict Ab epitopes at the residue level, based on structure and neutralization panels of diverse viral strains has been described. This method was evaluated using 19 Env-Abs, including 17b, against 181 diverse HIV-1 strains with available Ab-Ag complex structures. Chuang2013 (computational epitope prediction)
17b: The complexity of the epitopes recognized by ADCC responses in HIV-1 infected individuals and candidate vaccine recipients is discussed in this review. 17b is discussed as the CD4i CoRBS (Cluster C) region-targeting, neutralizing anti-gp120 mAb exhibiting ADCC activity and having a discontinuous epitope. Co-localization of the gp120_HXBc2core CD4/17b complex (PDB:1GC1) was studied by tomogram of the chimera. Pollara2013 (ADCC, review, structure)
1.7B: This study mapped the amino acid changes in epitopes that led to escape from the initial autologous neutralizing Ab response in two HIV-1 B infected individuals. Escape occurred by different pathways but the responses appeared to be directed against the same region of gp120. In conclusion, a region just below the base of the V3 loop, near the coreceptor binding domain of gp120, can be a target for autologous neutralization. MAb 1.7B was used as a noncompeting human Ab in cross competition analysis. Tang2011 (autologous responses, glycosylation, neutralization, escape, HAART, ART, structure)
17b: ADCC mediated by CD4i mAbs (or anti-CD4i-epitope mAbs) was studied using a panel of 41 novel mAbs. Three epitope clusters were classified, depending on cross-blocking in ELISA by different mAbs: Cluster A - in the gp120 face, cross-blocking by mAbs A32 and/or C11; Cluster B - in the region proximal to CoRBS (co-receptor binding site) involving V1V2 domain, cross-blocking by E51-M9; Cluster C - CoRBS, cross-blocking by 17b and/or 19e. The ADCC half-maximal effective concentrations of the Cluster A and B mAbs were generally 0.5^-1 log lower than those of the Cluster C mAbs, and none of the Cluster A or B mAbs could neutralize HIV-1. Cluster A's A32- and C11-blockable mAbs were suggested to recognize conformational epitopes within the inner domain of gp120 that involve the C1 region. Neutralization potency and breadth were also assessed for these mAbs. No correlation was found between ADCC and neutralization Abs' action or functional responses.17b was used as the classical CoRBS Ab control in different assays, especially competition ELISA assays to determine epitope specificity. Guan2013 (ADCC, antibody interactions)
17b: This study uncovered a potentially significant contribution of V_H replacement products which are highly enriched in IgH genes for the generation of anti-HIV Abs including anti-gp41, anti-V3 loop, anti-gp120, CD4i and PGT Abs. The V_H replacement "footprints" within CD4i Abs preferentially encode negatively charged amino acids within IgH CDR3. The details of 17b V_H replacement products in IgH gene and mutations and amino acid sequence analysis are described in Table 1,Table 2 and Fig 3. Liao2013a (antibody sequence)
17b: Cryoelectron tomography was used to determine structures of A12, m36, or m36/CD4 complexed to trimeric Env displayed on intact HIV-1 BaL virus. The foot print of m36 binding on gp120 is near the base of the V3 loop which resembles a "fully open" conformation similar to the coreceptor targeted CD4i mAb, 17b. Meyerson2013 (antibody binding site, structure)
Lists 7 mAbs derived from patient N70: 15E, 1.9B, 2.3A, 2.3B, 2.1H, F91, 1.7B. Robinson1992
17b: Systematic computational analyses of gp120 plasticity and conformational transition in complexes with CD4 binding fragments, mimetic proteins and Ab fragments is described to explain the molecular mechanisms by which gp120 interacts with the CD4bs at local and subdomain levels. An isotopic elastic network analysis, a full atomic normal mode analysis and simulation of conformational transitions were used to compare the gp120 structures in CD4 bound and 17b Ab-bound states. Korkut2012 (structure)
17b: Design, synthesis, characterization and structures of gp120 in complex with dual hot-spot HIV-1 entry inhibitor small-molecules is reported. 17b was used as a surrogate for the co-receptor and structure of HIV-1 CD4:gp120:17b complex is described. LaLonde2012 (structure)
17b: The sera of 20 HIV-1 patients were screened for ADCC in a novel assay measuring granzyme B (GrB) and T cell elimination and reported that complex sera mediated greater levels of ADCC than anti-HIV mAbs. The data suggested that total amount of IgG bound is an important determinant of robust ADCC which improves the vaccine potency. 17b was used as an anti CD4 binding Ab to study effects of Ab specificity and affinity on ADCC against HIV-1 infected targets. Smalls-Mantey2012 (ADCC, assay or method development)
17b: Isolation of VRC06 and VRC06b MAbs from a slow progressor donor 45 is reported. This is the same donor from whom bnMAbs VRC01, VRC03 and NIH 45-46 were isolated and the new MAbs are clonal variants of VRC03. 17b was used as a CoRB-specific MAb to compare binding specificity of VRC06. Li2012
17b: This is a comment on Tan2012. It is noted that Tran and colleagues used high-resolution 3D cryoelectron tomography to define the conformation of Env when bound to soluble CD4 and to a series of monoclonal antibodies. It was demonstrated that antibodies binding to the CD4 binding site or coreceptor binding site of Env may lead to significantly different conformations of the trimeric Env complex. VRC01 locks the complex in a closed conformation, while binding to soluble CD4 or the monoclonal antibody 17b fixed the trimer in an open conformation. Wright2012 (review, structure)
17b: Previous cryo-electron tomographic studies were extended. A more complete picture of the HIV entry process was presented by showing that HIV-1 Env binding to either soluble CD4 (sCD4) or the co-receptor mimic 17b leads to the same structural opening, or activation, of the Env spike. Atudy also demonstrated structurally that the broadly neutralizing antibodies VRC01, VRC02, VRC03 are able to block this activation, locking Env in a state that resembles closed, native Env. The cryo-electron microscopic structure of soluble trimeric Env in the 17b-bound state is presented at ˜9 Å resolution, revealing it as a novel, activated intermediate conformation of trimeric Env that could serve as a new template for immunogen design. Tran2012 (structure)
17b: A computational tool (Antibody Database) identifying Env residues affecting antibody activity was developed. As input, the tool incorporates antibody neutralization data from large published pseudovirus panels, corresponding viral sequence data and available structural information. The model consists of a set of rules that provide an estimated IC₅₀ based on Env sequence data, and important residues are found by minimizing the difference between logarithms of actual and estimated IC₅₀. The program was validated by analysis of MAb 8ANC195, which had unknown specificity. Predicted critical N-glycosylation for 8ANC195 were confirmed in vitro and in humanized mice. The key associated residues for each MAb are summarized in the Table 1 of the paper and also in the Neutralizing Antibody Contexts & Features tool at Los Alamos Immunology Database. West2013 (glycosylation, computational epitope prediction)
17b: Different adjuvants, including Freund's adjuvant (FCA/FIA), MF59, Carbopol-971P and 974P were compared on their ability to elicit antibody responses in rabbits. Combination of Carbopol-971P and MF59 induced potent adjuvant activity with significantly higher titer nAbs than FCA/FIA. There was no difference in binding of this MAb to gp140 SF162 with MF59 adjuvant, but there was 3-fold decrease of antigenicity with FIA, C971, C974, C971+MF59 C971+MF59 as compared to the unadjuvanted sample. Lai2012 (adjuvant comparison)
17b: Somatic hypermutations are preferably found in CDR loops, which alter the Ab combining sites, but not the overall structure of the variable domain. FWR of CDR are usually resistant to and less tolerant of mutations. This study reports that most bnAbs require somatic mutations in the FWRs which provide flexibility, increasing Ab breadth and potency. To determine the consequence of FWR mutations the framework residues were reverted to the Ab's germline counterpart (FWR-GL) and binding and neutralizing properties were then evaluated. 17b had limited neutralizing activity recognizing the CD4 induced site and carried fewer somatic mutations than bnAbs. Fig S4C described the comparison of Ab framework amino acid replacement vs. interactive surface area on 17b. Klein2013 (neutralization, structure, antibody lineage)
17b: Antigenic properties of 2 biochemically stable and homogeneous gp140 trimers (A clade 92UG037 and C clade CZA97012) were compared with the corresponding gp120 monomers derived from the same percursor sequences. The trimers had nearly all the antigenic properties expected for native viral spikes and were markedly different from monomeric gp120. Immobilized 17b Fab could capture gp120 even in the absence of CD4 and CD4 binding greatly increased the strength of interaction. In contrast, gp140 trimer bound to 17b Fab only in the presence of CD4, suggesting that gp120 portions of unligated epitope trimer are tightly confined in a conformation distinct from the CD4-bound state. Kovacs2012 (antibody binding site, neutralization, binding affinity)
17b: Intrinsic reactivity of HIV-1, a new property regulating the level of both entry and sensitivity to Abs has been reported. This activity dictates the level of responsiveness of Env protein to co-receptor, CD4 engagement and Abs. CD4 independence of the glycoprotein variants exhibits strong correlation with 17b binding. The viral sensitivity increases with the S375W mutation to 17b. Haim2011 (antibody interactions)
17b: The study used the swarm of quasispecies representing Env protein variants to identify mutants conferring sensitivity and resistance to BnAbs. Libraries of Env proteins were cloned and in vitro mutagenesis was used to identify the specific AA responsible for altered neutralization/resistance, which appeared to be associated with conformational changes and exposed epitopes in different regions of gp160. The result showed that sequences in gp41, the CD4bs, and V2 domain act as global regulator of neutralization sensitivity. 17b was used as BnAb to screen Env clones. N197H mutation caused increase in neutralization by 17b, but failed in highest concentration. ORourke2012 (neutralization)
17b: This study reports the isolation of a panel of Env vaccine elicited CD4bs-directed macaque mAbs and genetic and functional features that distinguish these Abs from CD4bs MAbs produced during chronic HIV-1 infection. 17b was used as a positive control Abs in competitive binding assay with non human primates mAbs. Sundling2012 (vaccine-induced immune responses)
17b: The goal of this study was to improve the humoral response to HIV-1 by targeting trimeric Env gp140 to B cells. The gp140 was fused to a proliferation-inducing ligand (APRIL), B cell activation factor (BAFF) and CD40 ligand (CD40L). These fusion proteins increased the expression of activation-induced-cytidine deaminase (AID) responsible for somatic hypermutation, Ab affinity maturation, and Ab class switching. The Env-APRIL induced high anti-Env responses against tier1 viruses. 17b was used in immunoprecipitation assay. Melchers2012 (neutralization)
17b: Synthesis of an engineered soluble heterotrimeric gp140 is described. These gp140 protomers were designed against clade A and clade B viruses. The heterotrimer gp140s exhibited broader anti-tier1 isolate neutralizing antibody responses than homotrimer gp140. 17b was used to determine and compare the immunogenicity of homo and heterotrimers gp140s and to investigate the relative exposure of the CCR5 co-receptor binding site. The relative binding of 17b to the Q461/SF162 nonlinker heterotrimer was greater than expected. Sellhorn2012 (vaccine antigen design)
17b: Crystal structures of unliganded core gp120 from HIV-1 clade B, C, and E were determined to understand the mechanism of CD4 binding capacity of unliganded HIV-1. The results suggest that the CD4 bound conformation represents "a ground state" for the gp120 core with variable loop. 17b was used as a control to prove whether the purified and crystallized gp120 is in the CD4 bound conformational state or not. Kwon2012 (structure)
17b: Role of envelope deglycosylation in enhancing antigenicity of HIV-1 gp41 epitopes is reported. The mechanism of induction of broad neutralizing Abs is discussed. The hypothesis of presence of "holes" in the naive B cell repertoires for unmutated B cell receptor against HIV-1 Env was tested. 17b was used in binding assays to compare glycosylated or deglycosylated JFRL and didn't exhibit strong binding to deglycosylated JRFL. The authors inferred that glycan interferences control the binding of unmutated ancestor Abs of broad neutralizing mAb to Env gp41. Ma2011 (glycosylation, neutralization)
17b: A panel of glycan deletion mutants was created by point mutation into HIV gp160, showing that glycans are important targets on HIV-1 glycoproteins for broad neutralizing responses in vivo. Enrichment of high mannose N-linked glycan(HM-glycan) of HIV-1 glycoprotein enhanced neutralizing activity of sera from 8/9 patients. 17b was used as a control to compare the neutralizing activity of patients' sera. Mutated glycan 241 (N241S) had an increase neutralization sensitivity to 17b. Lavine2012 (neutralization)
17b: To improve the immunogenicity of HIV-1 Env vaccines, a chimeric gp140 trimer in which V1V2 region was replaced by the GM-CSF cytokine was constructed. We selected GM-CSF was selected because of its defined adjuvant activity. Chimeric EnvGM-CSF protein enhanced Env-specific Ab and T cell responses in mice compared with wild-type Env. Probing with neutralizing antibodies showed that both the Env and GM-CSF components of the chimeric protein were folded correctly. 3 proteins were studied: Env-wild-type, Env-ΔV1V2, Env-hGM-CSF. In the absence of CD4, the CD4i epitope MAb 17b, 48d, and 412d bound poorly to Env-wild-type and Env-hGM-CSF but efficiently to Env-ΔV1V2. Adding soluble CD4 substantially increased the binding of these MAb to Env-ΔV1V2 and especially to Env-wild-type, but binding to Env-hGM-CSF was improved only modestly, suggesting that the presence of GM-CSF in the V1V2 region either limits the accessibility of the CD4i epitopes or blocks the conformational changes that expose them. vanMontfort2011 (vaccine antigen design)
17b: Broadly neutralizing antibodies circulating in plasma were studied by affinity chromatography and isoelectric focusing. The Abs fell in 2 groups. One group consisted of antibodies with restricted neutralization breadth that had neutral isoelectric points. These Abs bound to envelope monomers and trimers versus core antigens from which variable loops and other domains have been deleted. Another minor group consisted of broadly neutralizing antibodies consistently distinguished by more basic isoelectric points and specificity for epitopes shared by monomeric gp120, gp120 core, or CD4-induced structures. The pI values estimated for neutralizing plasma IgGs were compared to those of human anti-gp120 MAbs, including 5 bnMAbs (PG9, PG16, VRC01, b12, and 2G12), 2 narrowly neutralizing MAbs (17b and E51), and 3 nonneutralizing MAbs (A32, C11, and 19e). MAbs 17b and E51, with restricted neutralizing activity, had pIs from 7 to 7.85. Plasma-derived, anti-gp120 IgG fractions in this range also had narrow neutralization breadth. Sajadi2012 (polyclonal antibodies)
17b: Small sized CD4 mimetics (miniCD4s) were engineered. These miniCD4s by themselves are poorly immunogenic and do not induce anti-CD4 antibodies. Stable covalent complexes between miniCD4s and gp120 and gp140 were generated through a site-directed coupling reaction. These complexes were recognized by CD4i antibodies as well as by the HIV co-receptor CCR5 and elicited CD4i antibody responses in rabbits. A panel of MAbs of defined epitope specificities, including MAb 17b, was used to analyze the antigenic integrity of the covalent complexes using capture ELISA. Martin2011 (mimics, binding affinity)
17b: The long-term effect of broadly bNAbs on cell-free HIV particles and their capacity to irreversibly inactivate virus was studied. MPER-specific MAbs potently induced gp120 shedding upon prolonged contact with the virus, rendering neutralization irreversible. The kinetic and thermodynamic requirements of the shedding process were virtually identical to those of neutralization, identifying gp120 shedding as a key process associated with HIV neutralization by MPER bNAbs. Neutralizing and shedding capacity of 7 MPER-, CD4bs- and V3 loop-directed MAbs were assessed against 14 divergent strains. 17b was largely ineffective in both inducing neutralization and shedding. Ruprecht2011 (neutralization, kinetics)
17b: Deglycosylations were introduced into the 24 N-linked glycosylation sites of a R5 env MWS2 cloned from semen. Mutants N156-T158A, N197-S199A, N262-S264A and N410-T412A conferred decreased infectivity and enhanced sensitivity to a series of antibodies and entry inhibitors. Mutant N156-T158A showed enhanced neutralization sensitivity to MAb 17b in the absence of soluble CD4, suggesting that deglycosylation in these sites on gp120 may be beneficial for the exposure of a CD4 induced epitope which only exists in the CD4-liganded form of gp120. Huang2012 (glycosylation, neutralization)
17b: In order to increase recognition of CD4 by Env and to elicit stronger neutralizing antibodies against it, two Env probes were produced and tested - monomeric Env was stabilized by pocket filling mutations in the CD4bs (PF2) and trimeric Env was formed by appending trimerization motifs to soluble gp120/gp14. PF2-containing proteins were better recognized by bNMAb against CD4bs and more rapidly elicited neutralizing antibodies against the CD4bs. Trimeric Env, however, elicited a higher neutralization potency that mapped to the V3 region of gp120. Feng2012 (neutralization)
17b: A way to produce conformationally intact, deglycosylated soluble, cleaved recombinant Env trimers by inhibition of the synthesis of complex N-glycans during Env production, followed by treatment with glycosidases under conditions that preserve Env trimer integrity is described to facilitate crystallography and immunogenicity studies. Deglycosylation had no effect on basal or sCD4-induced interactions between the trimers and the coreceptor binding site-directed MAb 17b. Depetris2012 (glycosylation, binding affinity)
17b: The sera of 113 HIV-1 seroconverters from three cohorts were analyzed for binding to a set of well-characterized gp120 core and resurfaced stabilized core (RSC3) protein probes, and their cognate CD4bs knockout mutants. 17b did not bind to gp120 core, gp120 core D368R, RSC3, RSC3/G367R, RSC3 Δ3711, and RSC3 Δ3711/P363N. Lynch2012 (binding affinity)
17b: The study followed the dynamics of alternating viral neutralization phenotype over time in 7 patients monitored for 1-5 years starting from seroconversion. While the development of neutralization resistance, including escape from the autologous antibody response was observed, there was also temporal emergence of viruses exquisitely sensitive to both autologous and heterologous Nabs. All Envs with heightened serum sensitivity were also potently neutralized by sCD4 and/or IgG1b12.Neutralization by 17b in the absence of sCD4 was also observed. In contrast, out of nineteen serum resistant env-chimeras only three were neutralized by 17b in absence of sCD4. Aasa-Chapman2011 (autologous responses, escape)
17b: To test whether HIV-1 particle maturation alters the conformation of the Env proteins, a sensitive and quantitative imaging-based Ab-binding assay was used to probe the conformations of full-length and cytoplasmic tail (CT) truncated Env proteins on mature and immature HIV-1 particles. In the absence of sCD4, binding of MAb 17b to immature particles was approximately 40% less than binding to mature particles. 17b, A1g8, and E51 binding to immature virions was stimulated by sCD4 to a greater or equal extent vs. mature particles, with MAb 17b exhibiting the greatest increase. Truncation of the CT abolished the enhanced sCD4-induced binding of 17b to immature particles. This suggested that CD4 binding triggers exposure of some epitopes to an equal extent on immature and mature virions and other epitopes to a greater extent on immature virions. Joyner2011 (binding affinity)
17b: 17b MAb was used to study mechanism of neutralization by bnMAbs. In contrast to VRC01, PGV04 did not enhance 17b or X5 binding to their epitopes in the co-receptor region on the gp120 monomer, and in contrast to CD4, none of the CD4bs MAbs tested induced the 17b site on trimeric cleaved Env, suggesting that a degree of mimicry of CD4 by anti-CD4bs bnMAbs may be a consequence of binding to the CD4 epitope on monomeric gp120 rather than a neutralization mechanism. Falkowska2012 (neutralization)
17b: Broadly neutralizing HIV-1 immunity associated with VRC01-like antibodies was studied by isolation of VRC01-like neutralizers with CD4bs probe; structural definition of gp120 recognition by RSC3-identified antibodies from different donors; functional complementation of heavy and light chains among VRC01-like antibodies; identification of VRC01 antibodies by 454 pyrosequencing; and cross-donor phylogenetic analysis of sequences derived from the same precursor germline gene. 17b was studied among other antibodies that derive from a common IGHV1-69 allele to assess how atypical the VRC01-like antibody convergence was. T The angular difference in heavy-chain orientation between 17b, 412d, and X5 was over 90°, or roughly 10 times as much as among the VRC01-like antibodies. 17b had 41-62% sequence identity of its heavy and light chains to respective chains of VRC-PG04 and VRC-CH31. Wu2011 (structure)
17b: Molecular architectures of the soluble CD4 (sCD4)-bound states of SIV Env trimers for three different strains (SIVmneE11S, SIVmac239, and SIV CP-MAC) have been determined using cryo-electron tomography that showed only minor conformational changes following sCD4 binding in marked contrast to HIV-1 BaL, SIVmneE11S and SIVmac239. Binding of trimeric HIV-1gp120 to either sCD4 alone or to sCD4 in combination with the coreceptor mimic 17b results in an opening of the trimeric Env structure. Due to a dramatic difference between the angle of approach of MAbs 17b and that of SIV MAb 7D3, these Abs target epitopes on gp120 that are on opposites sides of the coreceptor binding site and in the vicinity of the V3 loop. White2011 (antibody binding site, structure)
17b: To address the controversy of significant differences in chosen atomic coordinates of monomeric SIV gp120 in unliganded, and monomeric HIV-1 gp120 in various liganded and antibodybound states, the molecular architectures of trimeric Env from SIVmneE11S, SIVmac239 and HIV-1 R3A strains are shown to be closely comparable to that previously determined for HIV-1 BaL. The gp120 density profiles obtained from the coordinates of the trimeric Env complex with sCD4/17b (1GC1) and b12 (2NY7) are similar even though there are important differences in their atomic resolution structures. White2010 (structure)
17b: This review outlines the general structure of the gp160 viral envelope, the dynamics of viral entry, the evolution of humoral response, the mechanisms of viral escape and the characterization of broadly neutralizing Abs. This MAb is noted in the review to be CD4i antibody and to have weak neutralizing activity against most HIV-1 isolates, with increased activity when soluble CD4 is added. Gonzalez2010 (neutralization, variant cross-reactivity, escape, review)
17b: Crystal structures of gp120 and gp41 in complex with CD4 and/or MAbs 17b, 48d, b12, b13, 412d, X5, 211C, C11, 15e, m6, m9 and F105 were used to determine the structure and the mobility of the gp41-interactive region of gp120. Elements determined to maintain the gp120-gp41 interaction were the gp120 termini and a newly described invariant 7-stranded β-sandwich. Structurally plastic elements of gp120 responsible for the various gp120 conformation changes due to receptor- or Ab-binding were structured into 3 layers, with the V1/V2 loops emanating from layer 2 and the highly glycosylated outer domain from layer 3. Pancera2010a (antibody binding site, structure)
17b: 37 Indian clade C HIV-1 Env clones obtained at different time points from five patients with recent infection, were studied in neutralization assays for sensitivities to their autologous plasma antibodies and mAbs. One Env clone each from patients IVC2 and IVC3 was neutralized by 17b suggesting spontaneous exposure of CD4i epitopes. Ringe2010 (neutralization)
17b: This paper shows that a highly neutralization-resistant virus is converted to a neutralization sensitive virus with a rare single mutation D179N in the C-terminal portion of the V2 domain. A panel of mutants were tested to determine whether they can improve the neutralization sensitivity of an extremely neutralization-resistant clinical isolate. 17b neutralized wildtype sensitive clone and 6 out of 9 mutants tested (D179N, D179E, D179Q, D179H, D179S and D179A). ORourke2010 (neutralization, variant cross-reactivity)
17b: MAb m9 showed superior neutralization potency compared to scFv 17b in a TZM-bl assay, where it neutralized all 15 isolates compared to 17b that neutralized only 2 isolates. Unlike m9, 17b did not compete with R5Nt for binding to gp120, indicating that the epitope for m9 differs from that of 17b. Zhang2010 (neutralization)
17b: A side-by-side comparison was performed on the quality of Ab responses in humans elicited by three vaccine studies focusing on Env-specific Abs. High frequency and titers of 17b-like Abs were detected in all three vaccine trials. 58% of sera from the HVTN 203 trial, 75% of sera from the HVTN 041 trial, and 81% of sera from the DP6-001 trial were able to outcompete binding to 17b MAb. Vaine2010 (antibody interactions)
17b: This review focuses on recent vaccine design efforts and investigation of broadly neutralizing Abs and their epitopes to aid in the improvement of immunogen design. NAb epitopes, NAbs response to HIV-1, isolation of novel mAbs, and vaccine-elicited NAb responses in human clinical trials are discussed in this review. Mascola2010 (review)
17b: A mathematical framework is designed to determine the number of Abs required to neutralize a single trimer called the stoichiometry of trimer neutralization. 15 different virus antibody combinations divided into five groups based on antibody binding sites were used in the designed model. 17b was classified into CD4i group as it binds CD4. The number of 17b Abs needed to neutralize a single trimer was determined to equal 1 with 99.8% probability. Magnus2010
17b: Four human anti-phospholipid mAbs were reported to inhibit HIV-1 infection of human PBMC's by binding to monocytes and releasing soluble chemokines. The ability of different anti-phospholid mAbs to inhibit pseudovirus infection was studied. MAb 17b was able to capture HIV-1 pseudovirions only in the presence of soluble CD4 and not in its absence. 17b did not induce the production of chemokines. Moody2010 (binding affinity)
17b: The antigenic structure of Gag-Env pseudovirions was characterized and it was shown that these particles can recapitulate native HIV virion epitope structures. 17b exhibited low level binding to the Gag-Env pseudovirions that was markedly improved in the presence of sCD4, indicating presence of native trimers. The Gag-Env pseudovirions were further used to identify a subset of antigen-specific B cells in chronically infected HIV subjects. Hicar2010 (binding affinity, structure)
17b: Molecular modeling was used to construct a 3D model of an anti-gp120 RNA aptamer, B40t77, in complex with gp120. Externally exposed residues of gp120 that participated in stabilizing interaction with the aptamer were mutated. Binding of 17b to gp120 was inhibited by B40t77, which is suggested to be due to the overlapping binding sites of the two molecules. Joubert2010 (binding affinity, structure)
17b: Biological effects of mutating I309L in HIV-1 subtype C Envs was examined. 4/11 mutated Envs showed moderate increase in their neutralization sensitivity to 17b after incubation with sCD4, indicating that I309L affects the efficiency with which the coreceptor binding site is formed. Lynch2010 (antibody binding site, neutralization)
17b: Unlike the MPER MAbs tested, 17b did not show any Env-independent virus capture in the conventional or in the modified version of the virus capture assay. Leaman2010
17b: Impact of in vivo Env-CD4 interactions was studied during vaccinations of Rhesus macaques with two Env trimer variants rendered CD4 binding defective (368D/R and 423/425/431 trimers) and wild-type (WT) trimers. Ab binding profiles of the three trimer variants were assessed by binding analyses to different MAbs. coreceptor binding site (CoRbs) directed MAb 17b bound similarly to WT and 368D/R trimers but its binding affinity was completely abrogated for 423/425/431 trimers. Douagi2010 (binding affinity)
17b: Peptide ligands for CD4i epitopes on native dualtropic Env were selected by phage display. The correct exposure of CD4i epitopes was detected with 17b, and incubation with sCD4 greatly enhanced its binding. An optimized synthetic peptide derivative (XD3) bound to all Env proteins analyzed with different coreceptor usage and inhibited binding of MAb 17b to immobilized gp120 in the presence and absence of sCD4 by 30 percent and 50 percent, respectively. Dervillez2010 (binding affinity)
17b: 21c binding, autoreactivity, polyreactivity and protective benefits are discussed and compared to other autoreactive MAbs, such as 2F5 and 4E10. Regulation of CD4i MAbs, such as 21c and 17b, by tolerance mechanisms is discussed. Haynes2010 (autoantibody or autoimmunity, antibody polyreactivity)
17b: Expression of gp120 was shown to lead to the accumulation of both monomeric gp120 and aberrant dimeric gp120 forms. Dimeric forms of gp120 were not recognized by CD4i MAbs, such as 17b, nor by MAbs against the gp120 inner domain, but were recognized by CD4BS MAbs. It is suggested that gp120 dimerization occludes or disrupts the inner domain and/or the co-receptor binding site. Formation of gp120 dimers was reduced by removal of the V1/V2 loops or the N and C termini. Finzi2010 (antibody binding site)
17b: 17b was linked with sCD4 and the construct was tested for its neutralization breadth and potency. sCD4-17b showed significantly greater neutralization breadth and potency compared to other MAbs (b12, 2G12, 2F5 and 4E10), neutralizing 100% of HIV-1 primary isolates of subtypes A, B, C, D, F, CRF01_AE and CRF02_AG. Unlike the other MAbs, sCD4-17b was equivalently active against virus particles generated from different producer cell types. Lagenaur2010 (neutralization, variant cross-reactivity, subtype comparisons)
17b: A set of Env variants with deletions in V1/V2 was constructed. Replication competent Env variants with V1/V2 deletions were obtained using virus evolution of V1/V2 deleted variants. Sensitivity of the evolved ΔV1V2 viruses was evaluated to study accessibility of their neutralization epitopes. In the absence of sCD4, 17b bound and neutralized ΔV1V2 variants more potently than the full-length trimer. Addition of sCD4 did not enhance 17b binding, as it was close to optimal without sCD4. 17b did not bind to the ΔV1V2 variant with V120K substitution. For the uncleaved variants, 17b bound to the ΔV1V2 but did not bind well to the full-length virus, unaffected by presence of sCD4. Bontjer2010 (neutralization, binding affinity)
17b:The effect of amino acid polymorphisms on the structural stability and cooperative interactions of gp120, from A and B subtype HIV-1, were compared using microcalorimetric techniques. The impact of these polymorphisms on the binding mechanisms of gp120-A and gp120-B to the host cell surface receptors and coreceptors was also studied for development of entry inhibitors. The binding affinity of 17b is increased by CD4 for gp120-B but only minimally increased for gp120-A. Binding of 17b to gp120-A induced smaller enthalpy and entropy changes compared to 17b binding to gp120-B, indicating that binding of this Ab to gp120-A induces smaller conformational changes. The epitope for this Ab is highly conserved between gp120-A and gp120-B proteins, although 17b has 3-fold weaker affinity for gp120-A. Brower2010 (kinetics, binding affinity, subtype comparisons)
17b: Neutralizing activities of 17b were similar against parent and GnTI (complex glycans of the neutralizing face are replaced by fully trimmed oligomannose stumps) viruses, and the N301Q mutant virus (glycan at position 301 is removed), with all viruses being resistant to neutralization by this Ab. Binley2010 (glycosylation, neutralization)
17b: Binding of 17b to Env HIV-1 JR-FL increased gradually as the amount of CD4-mimicking small compound NBD-556 increased. Pretreatment by NBD-556 remarkably increased binding of 17b to JR-FL Env, indicating enhancement of 17b epitope accessibility by NBD-556. Yoshimura2010 (mimics, binding affinity)
17b: A panel of 109 HIV-1 pseudoviruses was assessed for neutralization sensitivities to 17b MAb and patient plasma pools from genetically diverse HIV-1 positive samples. Clustering analyses revealed that the 109 viruses could be divided to 4 sub-groups, based on their neutralization sensitivity to the plasma pools: very high (Tier 1A), above-average (Tier 1B), moderate (Tier 2), and low (Tier 3) sensitivity. 3 Tier 1A, 6 Tier 1B, 1 Tier 2 but no Tier 3 viruses were found to be sensitive to neutralization by 17b. Seaman2010 (neutralization)
1.7B: gp41 L669S mutant virus was moderately sensitive to neutralization by 1.7B while the L669 wild type virus was resistant. This indicates that conformational changes in the MPER could alter the exposure of neutralization epitopes in other regions of HIV-1 Env. Shen2010 (neutralization)
17b: Fusion of CD4 with 17b scFv resulted in CD4-scFv17b reagent with neutralization potency comparable to other CD4-CD4i complexes. The neutralization potency was improved by inclusion of an IgG Fc region and by linkage of CD4 to the heavy chain of 17b. The resulting CD4hc-IgG17b neutralized a range of clade A, B and C viruses with potency comparable to other broadly neutralizing Abs. The complex, however, had low expression levels. West2010 (neutralization, variant cross-reactivity, subtype comparisons)
17b: To examine the antigenicity of a defined Ab epitope on the functional envelope spike, a panel of chimeric viruses engrafted at different positions with the hemagglutinin (HA) epitope tag was constructed. 17b neutralized 5/6 chimeric viruses poorly, indicating that the quaternary structure of the spikes was maintained. One virus with the HA-tag inserted in the V2 loop was more sensitive to neutralization by 17b than the wild type, indicating that the HA tag had resulted in localized alternation of gp120. Pantophlet2009 (neutralization)
17b: NAb specificities of a panel of HIV sera were systematically analyzed by selective adsorption with native gp120 and specific mutant variants. The integrity of gp120 beads in adsorption assay were validated by binding analysis to 17b. gp120 point mutation D368R was used to screen the sera for CD4bs- Abs, and it was shown that this mutant could adsorb binding activity of 17b. To test for presence of coreceptor binding region MAbs in sera, gp120 I420 mutant was used. This mutant was not recognized by 17b, and it could not adsorb binding activity of 17b in adsorption assay. In some of the broadly neutralizing sera, the gp120-directed neutralization was mapped to CD4bs. Some sera were positive for NAbs against coreceptor binding region. A subset of sera also contained NAbs directed against MPER. Li2009c (assay or method development)
17b: The review discusses the implications of HIV-1 diversity on vaccine design and induction of neutralizing Abs, and possible novel approaches for rational vaccine design that can enhance coverage of HIV diversity. Patterns of within-clade and between-clade diversity in core epitopes of known potent neutralizing Abs is displayed. Korber2009 (review)
17b: A set of Env variants with deletions in V1/V2 were constructed. Replication competent Env variants with V1/V2 deletions were obtained using virus evolution of V1/V2 deleted variants. Most V1/V2 deleted viruses were sensitive to neutralization by 17b, while the wild type and the evolved variants were resistant. This indicated that deletion of V1/V2 increases exposure of 17b epitope, and that the compensation mutations in the evolved viruses damage 17b epitope. Bontjer2009 (antibody binding site, neutralization)
17b: The crystal structure for VRC01 in complex with an HIV-1 gp120 core from a clade A/E recombinant strain was analyzed to understand the structural basis for its neutralization breadth and potency. 17b bound with high affinity to CD4-bound but not to non-CD4-bound gp120 conformation. The number of mutations from the germline and the number of mutated contact residues for 17b were smaller than those for VRC01. Zhou2010 (neutralization, binding affinity, structure)
17b: Resurfaced stabilized core 3 (RSC3) protein was designed to preserve the antigenic structure of the gp120 CD4bs neutralizing surface but eliminate other antigenic regions of HIV-1. RSC3 did not show binding to 17b. Memory B cells were selected that bound to RSC3 and full IgG mAbs were expressed. Binding of 17b to gp120 was enhanced by the addition of two newly detected mAbs VRC01 and VRC02. Wu2010 (antibody interactions, binding affinity)
17b: Flexibility and rigidity of gp120 structures in isolation and in complex with CD4, CD4-mimics, and NAbs was analyzed using Floppy Inclusion and Rigid Substructure Topography program. The mean global flexibility of CD4/17b-bound gp12 was lower than that of b12-bound gp120. A common rigid core including residues 335-352 of gp120 was found, regardless of the strain or binding patterns. Tan2009 (antibody binding site)
17b: Combinations of loop alternations, filling hydrophobic pockets (F-mutations) and introduction of inter-domain cysteine pairs (D-mutations) were used to construct four immunogens with stabilized gp120 core. Modified truncations of the V1V2 and the V3 loop significantly increased 17b binding, even in the absence of CD4, and introduction of stabilizing F and D mutations significantly increased the on-rates of 17b interaction. Immunization assays revealed that the truncated core protein induced much higher titer of CD4bs-directed Abs than CD4i Abs, while conformationally stabilized mutant did the opposite. Dey2009 (kinetics, binding affinity)
17b: A review about the in vivo efficacy of MAbs against HIV-1, and about inhibition of HIV-1 infection by MAb fragments (Fab, scFv), including single molecules or fusion proteins of 17b. Also, the efficacy of engineered human Ab variable domains or "domain antibodies" (dAbs) as therapeutic agents is reviewed. Chen2009b (neutralization, immunotherapy, review)
17b: Affinity and changes in enthalpy and entropy of 17b binding to gp120/sCD4 complex were evaluated. S22 peptide, which is a 22 aa tyrosine-sulfated peptide corresponding to the CCR5 N-terminal region, competitively inhibited 17b. Brower2009 (kinetics, binding affinity)
17b: OD (GSL)(δβ20-21)(hCD4-TM) glycoprotein variant was constructed by eliminating V1 and V2 regions, truncating V3, and deleting cleavage, fusion, and interhelical domains from Env derivatives from R3A TA1 virus. In addition, the variant was membrane-anchored, the β20-β21 hairpin was truncated, and the central 20 amino acids of the V3 loop were replaced with a basic hexapeptide. Although this variant showed increased binding to b12 and 2G12, it did not bind to 17b. Wu2009a (binding affinity)
17b: 17b competed slightly with the broadly neutralizing Ab PG9 for binding to gp120. Walker2009a
17b: Δ9-12a, a mutant virus derived from an in-vitro passaged virus with four residues removed from the V3 stem, was shown to be completely resistant to CCR5 inhibitors and to neutralization by 17b. TA1, a mutant with a 15 amino acid deletion of the distal half of V3, was extremely sensitive to neutralization by 17b. Nolan2009 (neutralization)
17b: Binding of 17b to gp120 was not inhibited by YZ23, an Ab derived from mice immunized with eletcrophilic analogs of gp120 (E-gp120), indicating no overlap of these MAb epitopes. Nishiyama2009
17b: EpiSearch is an algorithm that predicts the location of conformational epitopes on the surface of an antigen by using peptide sequences from phage display experiments as input and ranking surface exposed patches according to the frequency distribution of similar residues in the peptides and in the patch. When tested for 17b, the conformational epitope was predicted correctly with terminal cysteine residues, but when these were omitted the accuracy of the method was lowered. Negi2009 (computational epitope prediction)
17b: Subtype A gp140 SOSIP trimers were recognized by 17b. Kang2009
17b: The Ig usage for variable heavy chain of this Ab was as follows: IGHV:1-69, IGHD:nd, D-RF:nd, IGHJ:1. Non-V3 mAbs preferentially used the VH1-69 gene segment. In contrast to V3 mAbs, these non-V3 mAbs used several VH4 gene segments and the D3-9 gene segment. Similarly to the V3 mAbs, the non-V3 mAbs used the VH3 gene family in a reduced manner. Anti-CD4i mAbs exclusively used the VH1 gene family. Gorny2009 (antibody sequence)
17b: Ten new non-neutralizing, cross-reactive mAbs were found in immunized mice. 17b was able to bind free virions, which was increased by addition of sCD4, while the newly detected mAbs could not bind free virions. Gao2009
17b: Two chimeras were constructed from a new HIV-2KR.X7 proviral scaffold where the V3 region was substituted with the V3 from HIV-1 YU2 and Ccon, generating subtype B and C HIV-2 V3 chimera. Both chimera, and the wildtype HIV-2KR and its derivatives HIV-2KR.X4 and HIV-2KR.X7 were resistant to neutralization by 17b. Davis2009 (neutralization)
17b: Two different but genetically related viruses, CC101.19 and D1/85.16, which are resistant to small molecule CCR5 inhibitors, and two clones from their inhibitor sensitive parental strain CC1/85, were used to analyze interactions of HIV-1 with CCR5. CC101.19 had 4 substitutions in the V3 region and D1/85.16 had 3 changes in gp41. CC101.19 was the most neutralization sensitive to 17b, while this Ab had limited neutralization activity to the two parental clones and to D1/85.16. However, gp120 from CC1/85 and D1/85.16 were the most reactive with 17b, and gp120 from all four viruses was equally reactive with 17b when sCD4 was added. This indicates that at least one major element of the CCR5 binding site has become accessible in the inhibitor-resistant CC101.19 virus. Berro2009 (neutralization)
17b: 17b neutralized Tier 1 but not Tier 2 viruses. Crystal structure of F105 in complex with gp120 revealed that all four strands of the bridging sheet were displaced to uncover a hydrophobic region which served for F105 binding. A monomeric disulfide gp120 variant was bound by 17b, suggesting that 17b does not rely on access to the hydrophobic surface for binding. Binding affinity and kinetics of 17b binding to several gp120 variants as assessed. Chen2009 (neutralization, kinetics, binding affinity)
17b: This report investigated whether mannose removal alters gp120 immunogenicity in mice. Approximately 55 mannose residues were removed from gp120 by mannosidase digestion creating D-gp120 for immunization. 17b was able to bind to D-gp120 comparably as to the untreated gp120, indicating that the mannosidase digestion did not affect the antigenicity of gp120. Banerjee2009 (binding affinity)
17b: An R5X4 HIV-1 strain, R3A, could tolerate partial loss of its V3 loop, but was poorly functional. After passage in tissue culture, the virus (now called TA1) still had a truncated V3 loop, but had acquired five mutations in its env gene and had also regained its function. TA1 was sensitive to neutralization by 17b MAb while the parental R3A was resistant to neutralization by this Ab. Viruses with Envs containing two or three of the five adaptive mutations were less sensitive to neutralization by 17b than TA1. Thus, the V3 truncation played a central role in sensitivity to 17b, but the adaptive mutations substantially increased sensitivity of the virus to 17b. Agrawal-Gamse2009 (neutralization)
17b: 17b neutralized infection of PBLs with R5 HIV-1 strains with higher potency than X4 HIV-1 strains. However, 17b did not inhibit transcytosis of cell-free or cell-associated virus across a monolayer of epithelial cells. A mixture of 13 MAbs directed to well-defined epitopes of the HIV-1 envelope, including 17b, did not inhibit HIV-1 transcytosis, indicating that envelope epitopes involved in neutralization are not involved in mediating HIV-1 transcytosis. When the mixture of 13 MAbs and HIV-1 was incubated with polyclonal anti-human γ chain, the transcytosis was partially inhibited, indicating that agglutination of viral particles at the apical surface of cells may be critical for HIV transcytosis inhibition by HIV-specific Abs. Chomont2008 (neutralization)
17b: A chimeric protein entry inhibitor, L5, was designed consisting of an allosteric peptide inhibitor 12p1 and a carbohydrate-binding protein cyanovirin (CNV) connected via a flexible linker. The L5 chimera inhibited 17b-gp120 interaction, but the CNV alone had a limited effect, indicating that the chimera has the high affinity binding property of the CNV molecule and the inhibitory property of the 12p1 peptide. McFadden2007
17b: This review summarizes data on possible vaccine targets for elicitation of neutralizing Abs and discusses whether it is more practical to design a clade-specific than a clade-generic HIV-1 vaccine. Development of a neutralizing Ab response in HIV-1 infected individuals is reviewed, including data that show no apparent division of different HIV-1 subtypes into clade-related neutralization groups. The neutralizing activity of CD4i Abs, such as 17b, is discussed. McKnight2007 (review)
17b: This review provides information on the HIV-1 glycoprotein properties that make it challenging to target with neutralizing Abs. 17b neutralization properties and binding to HIV-1 envelope, and current strategies to develop versions of the Env spike with functional trimer properties for elicitation of broadly neutralizing Abs, are discussed. In addition, approaches to target cellular molecules, such as CD4, CCR5, CXCR4, and MHC molecules, with therapeutic Abs are reviewed. Phogat2007 (review)
17b: 17b structure, binding, neutralization, and strategies that can be used for vaccine antigen design to elicit 17b-like Abs, are reviewed in detail. Lin2007 (review, structure)
17b: This review summarizes 17b Ab epitope, properties and neutralization activity. The effect of differential CCR5 cell surface expression on 17b neutralization activity is discussed. Kramer2007 (co-receptor, neutralization, review)
17b: gp120 proteins with double mutation T257S+S375W, which alters the cavity at the epicenter of the CD4 binding region, showed a weak interaction with 17b in the absence of CD4 and efficient interaction with maximal 17b binding in the presence of 17b. Similar results were observed with unmodified gp120, indicating that although properly folded, the mutant proteins were not completely stabilized in the CD4-bound conformation by the two mutations. The gp120 proteins with double mutation T257S+S375W were used to immunize rabbits. The ability of rabbit sera to affect binding of CD4 to unmodified gp120 proteins was tested. CD4 binding to gp120 was enhanced by 17b. Dey2007a (binding affinity)
17b: The various effects that neutralizing and non-neutralizing anti-envelope Abs have on HIV infection are reviewed, such as Ab-mediated complement activation and Fc-receptor mediated activities, that both can, through various mechanisms, increase and decrease the infectivity of the virus. The importance of these mechanisms in vaccine design is discussed. The unusual features of the 17b MAb are described. Willey2008 (review)
17b: A mathematical model was developed and used to derive transmitted or founder Env sequences from individuals with acute HIV-1 subtype B infection. All of the transmitted or early founder Envs were resistant to neutralization by 17b, while Envs from three chronically infected patients were unusually sensitive to neutralization by 17b. This indicated that the coreceptor binding surfaces on transmitted/founder Envs are conformationally masked. Keele2008 (neutralization, acute/early infection)
1.7b: Transmission of HIV-1 by immature and mature DCs to CD4+ T lymphocytes was significantly higher for CXCR4- than for CCR5-tropic strains. Preneutralization of R5 virus with 1.7b prior to capture efficiently blocked transmission to 44%, while preineutralization of X4 virus with 1.7b had no effect, indicating that 1.7b treatment results in more efficient transfer of X4 than of R5 HIV-1. vanMontfort2008 (co-receptor, neutralization, dendritic cells)
17b: An R5 HIV variant, in contrast to its parental virus, was shown to infect T-cell lines expressing low levels of cell surface CCR5 and to infect cells in the absence of CD4. The variant was seven-fold more sensitive to neutralization by 17b than the parental virus, indicating that the CCR5 binding site of gp120 is partially exposed on the mutant virus without prior binding to CD4. These properties of the mutant virus were determined by alternations in gp41. Taylor2008 (co-receptor, neutralization)
17b: Trimeric envelope glycoproteins with a partial deletion of the V2 loop derived from subtype B SF162 and subtype C TV1 were compared. The magnitude of 17b binding to subtype C trimer was lower than to subtype B trimer, either in the presence or absence of CD4. However, the fold increase in binding of 17b in presence of CD4 was similar for both subtypes, indicating similar structural rearrangements. Subtype C trimer had many biophysical, biochemical, and immunological characteristics similar to subtype B trimer, except for a difference in the three binding sites for CD4, which showed cooperativity of CD4 binding in subtype C but not in subtype B. Srivastava2008 (binding affinity, subtype comparisons)
17b: In order to assess whether small molecule CCR5 inhibitor resistant viruses were more sensitive to neutralization by NAbs, two escape mutant viruses, CC101.19 and D1/85.16, were tested for their sensitivity to neutralization by 17b, compared to the sensitivity of CC1/85 parental isolate and the CCcon.19 control isolate. The CC101.19 escape mutant has 4 sequence changes in V3 while the D1/85.16 has no sequence changes in V3 and relies on other sequence changes for its resistance. None of the control or resistant viruses were sensitive to neutralization by 17b. Pugach2008 (co-receptor, neutralization)
17b: The sensitivity of R5 envelopes derived from several patients and several tissue sites, including brain tissue, lymph nodes, blood, and semen, was tested to a range of inhibitors and Abs targeting CD4, CCR5, and various sites on the HIV envelope. All but one envelopes from brain tissue were macrophage-tropic while none of the envelopes from the lymph nodes were macrophage-tropic. Macrophage-tropic envelopes were also less frequent in blood and semen. None of the patient envelopes were inhibited by 17b, indicating that 17b epitope is not more exposed on macrophage-tropic envelopes than on non-macrophage tropic ones. Peters2008a (neutralization)
17b: Crystal structures of CD4M47 (a derivative of a synthetic miniprotein with HIV-1 gp120 binding surface of the CD4 receptor incorporated) and a phenylalanine variant ((Phe23)M47) were determined in ternary complexes with HIV-1 gp120 and 17b Ab. The structures revealed correlation between mimetic affinity of the miniprotein for gp120 and overall mimetic-gp120 interactive surface. Stricher2008 (structure)
17b: A series of peptide conjugates were constructed via click reaction of both aryl and alkyl acetylenes with an internally incorporated azidoproline 6 derived from parent peptide RINNIPWSEAMM. Many of these conjugates exhibited increase in both affinity for gp120 and inhibition potencies at both the CD4 and coreceptor binding sites. All high affinity peptides inhibited the interactions of YU2 gp120 with 17b Ab. Inhibition was found to be concentration-dependent. The aromatic, hydrophobic, and steric features in the residue 6 side-chain were found important for the increased affinity and inhibition of the high-affinity peptides. No inhibition of gp120 binding to 17b was observed for position 7 homoalanine-derived conjugates. Gopi2008
17b: Requirements for elicitation of CD4i Abs were examined by immunizing non-primate monkeys, rabbits, and human-CD4 transgenic (huCD4) rabbits with trimeric gp140. The trimers were well recognized by 17b in the absence of CD4 but the relative binding affinity increased 2-5-fold in the presence of sCD4. The avidity of the trimers for 17b in the absence of CD4 was determined to be in the low nanomolar range. Sera from immunized monkeys were able to inhibit 17b binding at a 10-fold higher dilution than sera from immunized rabbits. 17b could bind to the gp140 trimers bound to cell-surface CD4 as well, confirming that the co-receptor site is accessible after trimer binding to membrane-bound CD4. Forsell2008 (antibody binding site, binding affinity)
17b: Neutralization of JRFL, ADA, and YU2 isolates by 17b increased only modestly with increased dose of sCD4, and was never above 50%, indicating that the dose of sCD4, although enough to expose the V3 region, was insufficient to induce full conformational exposure of the co-receptor binding site. Wu2008 (neutralization)
17b: A new purification method was developed using a high affinity peptide mimicking CD4 as a ligand in affinity chromatography. This allowed the separation in one step of HIV envelope monomer from cell supernatant and capture of pre-purified trimer. Binding of 17b to gp120SF162 purified by the miniCD4 affinity chromatography and a multi-step method was comparable, suggesting that the miniCD4 allows the separation of HIV-1 envelope with intact 17b epitope. gp140DF162ΔV2 was purified by the miniCD4 method to assess its ability to capture gp140 trimers. Binding of 17b to gp140DF162ΔV2 purified by the miniCD4 affinity chromatography and a multi-step method was comparable, suggesting that the SF162 trimer antigenicity was preserved. Martin2008 (assay or method development, binding affinity)
17b: Variable domains of three heavy chain Abs, the VHH, were characterized. The Abs were isolated from llamas, who produce immunoglobulins devoid of light chains, immunized with HIV-1 CRF07_BC, to gp120. It was hypothesized that the small size of the VHH, in combination with their protruding CDR3 loops, and their preference for cleft recognition and binding into active sites, may allow for recognition of conserved motifs on gp120 that are occluded from conventional Abs.17b provided some inhibition of binding of the three neutralizing VHH Abs to gp120, suggesting that 17b imposes steric hinderance to binding of the VHH Abs to gp120. Forsman2008 (antibody interactions)
17b: Three-dimensional structures of trimeric Env displayed on native HIV-1 in complex with CD4 and the Fab fragment of 17b were compared to the unligated state, using cryo-electron tomography combined with three-dimensional image classification and averaging. Binding of 17b and CD4 resulted in dramatic conformational changes, including lever-like opening of the trimer. Binding of CD4 made way for exposure of gp41 stalk, and the V3 region was released from the lateral edge of the spike to point towards the target cell. V1/V2 and CD4 binding site moved away from the centre of the spike. Liu2008 (antibody binding site, structure)
17b: V3 loop deletions were introduced into three different primary HIV-1 strains: R3A, DH12, and TYBE. The deletions included: ΔV3(12,12) containing the first and the last 12 residues of the V3 loop, ΔV3(9,9) containing first and last 9 residues, and ΔV3(6,6) containing first and last 6 residues. Only HIV-1 R3A ΔV3(9,9) was able to support cell fusion. Passaging of this virus resulted in a virus strain (TA1) that replicated with wildtype kinetics, and that acquired several adaptive changes in gp120 and gp41 while retaining the V3 loop truncation. 17b neutralized a ΔV1/V2 virus but failed to neutralize R3A or LAI. TA1 was 100-fold more sensitive to neutralization by 17b than the ΔV1/V2 virus. Laakso2007 (neutralization)
17b: HIV-1 env clones resistant to cyanovirin (CV-N), a carbohydrate binding agent, showed amino acid changes that resulted in deglycosylation of high-mannose type residues in the C2-C4 region of gp120. Compared to their parental virus HIV-1 IIIB, these resistant viruses maintained similar sensitivity to 17b, as the glycan at position 301 in the V3 loop was intact. Hu2007 (neutralization, escape)
17b: Five amino acids in the gp41 N-terminal region that promote gp140 trimerization (I535, Q543, S553, K567 and R588) were considered. Their influence on the function and antigenic properties of JR-FL Env expressed on the surfaces of pseudoviruses and Env-transfected cells was studied. Various non-neutralizing antibodies bind less strongly to the Env mutant, but neutralizing antibody binding is unaffected. 17b captured both pseuduvirion preparations weakly in the absence of sCD4, but its binding was increased when sCD4 was also present. 17b failed to inhibit infection by either pseudovirus. Dey2008 (binding affinity)
17b: Molecular mechanism of neutralization by MPER antibodies, 2F5 and 4E10, was studied using preparations of trimeric HIV-1 Env protein in the prefusion, the prehairpin intermediate and postfusion conformations. MAb 17b was used to analyze antigenic properties of construct 92UG-gp140-Fd, derived from isolate 92UG037.8 and stabilized by a C-terminal foldon tag. Uncleaved 92UG-gp140-Fd binds 17b, but only in the presence of CD4. Frey2008 (binding affinity)
17b: A D386N change in the V4 region, which results in restoration of N-glycosylation at this site, did not have any impact on the neutralization of a mutant virus by 17b compared to wildtype. Also, there was no association between increased sensitivity to 17b neutralization and enhanced macrophage tropism. Dunfee2007 (neutralization)
17b: This review summarizes data on the development of HIV-1 centralized genes (consensus and ancestral) for induction of neutralizing antibody responses. Functionality and conformation of native epitopes in proteins based on the centralized genes was tested and confirmed by binding to 17b and other MAbs. Binding of 17b following CD4 also indicated presence of functionally relevant conformational changes of the proteins. Gao2007 (review)
17b: Macaques were immunized with either CD4, gp120, cross-linked gp120-human CD4 complex (gp120-CD4 XL), and with single chain complex containing gp120 rhesus macaque CD4 domains 1 and 2 (rhFLSC). Sera from the rhFLSC immunized animals showed highest competition titers, being able to block gp120-CD4 complex interactions with 17b more efficiently than sera from animals immunized with the three other proteins. DeVico2007 (neutralization)
17b: Interactions of this Ab with gp120 monomer and two cleavage-defective gp140 trimers were studied. It was shown that 17b interactions with the soluble monomers and trimers were dramatically decreased by GA cross-linking of the proteins, indicating that the 17b epitope was affected by cross-linking. This Ab was associated with a large entropy change upon gp120 binding. 17b was shown to have a kinetic disadvantage as it bound to gp120 much slower than the highly neutralizing Abs 2G12 and IgG1b12. Yuan2006 (antibody binding site, antibody interactions, kinetics, binding affinity)
17b: The neutralizing activity of coreceptor-binding site Abs, such as 17b, is reviewed. Pantophlet2006 (antibody binding site, neutralization)
17b: The G314E escape variant highly resistant to KD-247 was shown to be more sensitive to 17b Ab than the wildtype virus. 17b was shown to be able to bind and neutralize the escape virus even in the absence of rsCD4 while rsCD4 was necessary for binding of 17b to the wildtype virus, indicating that the G314E mutation induces the expression of epitopes for Abs against CD4i epitope and V3 loop. Yoshimura2006 (neutralization, escape, binding affinity)
17b: Binding of 17b in the presence or absence of CD4 to wt gp120 and two constructs with 5 and 9 residues deleted in the middle of the beta3-beta5 loop in the C2 region of gp120 was examined. In concordance with previous studies, 17b did not bind wt gp120 in absence of CD4 but did bind it in the presence of CD4. In contrast, the two deletion constructs did not bind 17b regardless of presence or absence of CD4 indicating that the loop-deleted gp120 is unable to close up the bridging sheet and display the coreceptor site and the 17b epitope. Rits-Volloch2006 (antibody binding site, binding affinity)
17b: gp120 (monomer), gp120deltaV2 (trimer), gp140 (monomer) and gp140deltaV2 (trimer) from subtype B SF162 were expressed in cells and their affinity for 17b was assessed. All four Envs bound to 17b in the absence of CD4 but the monomers showed 3-fold higher affinity for this Ab than trimers. In the presence of CD4, the 17b epitope was up-regulated in all Envs. Sharma2006 (antibody binding site, binding affinity)
17b: This Ab was used in a microcantilever deflection assay to detect gp120 from solution. Deflection twice that of the baseline that was detected upon specific binding of gp120 to cantilevers decorated on one side with A32 was further increased by subsequent incubation with 17b. Lam2006 (assay or method development)
17b: Viruses with V2 mutations R166K, D167N and P175L were resistant to 17b and a reduction of binding 17b to these viral variants was observed. Shibata2007 (escape, binding affinity)
1.7b: 1.7b-neutralized HIV-1 captured on Raji-DC-SIGN cells or immature monocyte-derived DCs (iMDDCs) was successfully transferred to CD4+ T lymphocytes, indicating that the 1.7b-HIV-1 complex was disassembled upon capture by DC-SIGN-cells. vanMontfort2007 (neutralization, dendritic cells)
17b: Chimeric VLPs, containing chimeric Con-S ΔCFI Env proteins with heterologous signal peptide (SP), transmembrane (TM), and cytoplasmic tail (CT) sequences, were all induced to bind to 17b after binding to CD4, indicating that chimeric Envs in VLPs undergo conformational changes induced by CD4. Wang2007a (antibody binding site, vaccine antigen design, binding affinity)
17b: The structure of the 17b MAb, particularly its CDRH3 region tyrosine sulfation, is reviewed. Also, the mechanism of its binding to the coreceptor binding site of gp120, and comparisons of the neutralizing potencies of 17b Ab fragments vs the whole IgG molecule are discussed. Engineering of Abs based on revealed structures of broadly neutralizing MAbs is discussed. Burton2005 (antibody binding site, neutralization, review, structure)
17b: Monomeric gp120 and trimeric gp140CF proteins synthesized from an artificial group M consensus Env gene (CON6) did not bind to 17b directly, but bound to it following binding to sCD4 and A32, indicating correct conformational change and subsequent exposure of the 17b epitope. Gao2005a (antibody binding site, binding affinity)
17b: The structure of the V3 region in the context of gp120 core complexed to the CD4 receptor and to the 17b Ab was attempted to be determined by X-ray resolution, but only the structure for V3 complexed with CD4 and X5 Ab was solved. Accessibility of the co-receptor binding site to this MAb is shown in a 3D figure. Huang2005 (antibody binding site, structure)
17b: Point mutations in the highly conserved structural motif LLP-2 within the intracytoplasmic tail of gp41 resulted in conformational alternations of both gp41 and gp120. The alternations did not affect virus CD4 binding, coreceptor binding site exposure, or infectivity of the virus, but did result in decreased binding and neutralization by certain MAbs and human sera. 17b exhibited similar levels of binding to both the LLP-2 mutant and wildtype viruses, indicating that sCD4 binding to the LLP-2 mutant successfully triggered conformational change of gp120 and exposure of the co-receptor binding site. Kalia2005 (antibody binding site, binding affinity)
17b: A series of genetically modified Env proteins were generated and expressed in both insect and animal cells to be monitored for their antigenic characteristics. For 17b, three of the modified proteins expressed in insect cells, including dV1V2 mutant (V1V2 deletions) followed by 3G-dV2-1G mutant (3G being mutations in three glycosylation sites and 1G being a mutation near the TM domain) and 3G-dV2 mutant, showed higher binding to the Ab than the wildtype did. This indicated that the dV1V2 mutant may expose 17b epitope better than the other Env proteins. When expressed in animal cells, only mutants 3G and dV2 showed enhanced binding to 17b but only at high concentrations of the MAb. Kang2005 (antibody binding site, binding affinity)
17b: A stable trimerization motif, GCN4, was appended to the C terminus of YU2gp120 to obtain stable gp120 trimers (gp120-GCN4). Each trimer subunit was capable of binding IgG1b12, indicating that they were at least 85% active. D457V mutation in the CD4 binding site resulted in a decreased affinity of the gp120-GCN4 trimers for CD4 and for 17b. Both the CNG-gp120 trimers and the D457V mutants showed a restricted stochiometry to 17b of one Ab molecule binding per trimer. Removal of the V1-V2 loops resulted in binding of three 17b molecules per trimer. Pancera2005a (binding affinity, structure)
17b: R-FL and YU2 HIV-1 strains were not neutralized by 17b.17b and other non-neutralizing Abs only recognized JR-FL cleavage-defective glycoproteins, while the neutralizing Abs (2G12 and IgG1b12) recognized both cleavage competent and cleavage-defective glycoproteins. It is suggested that an inefficient env glycoprotein precursor cleavage exposes non-neutralizing determinants, while only neutralizing regions remain accessible on efficiently cleaved spikes. For YU2, both cleavage-competent and -defective glycoproteins were recognized by both neutralizing and non-neutralizing Abs.17b, along with other Abs able to neutralize lab-adapted isolates, displayed enhanced viral entry at higher Ab concentrations, whereas the Abs that cannot neutralize any virus did not display such enhancement. Pancera2005 (antibody binding site, enhancing activity, neutralization, binding affinity)
17b: Escape mutations in HR1 of gp41 that confer resistance to Enfuvirtide reduced infection and fusion efficiency and also delayed fusion kinetics of HIV-1. The mutations also conferred increased neutralization sensitivity of virus to 17b. Enhanced neutralization correlated with reduced fusion kinetics, indicating that the mutations result in Env proteins remaining in the CD4-triggered state for a longer period of time. Reeves2005 (antibody binding site, drug resistance, neutralization, escape, HAART, ART)
17b: This review summarizes data on the role of NAb in HIV-1 infection and the mechanisms of Ab protection, data on challenges and strategies to design better immunogens that may induce protective Ab responses, and data on structure and importance of MAb epitopes targeted for immune intervention. The importance of standardized assays and standardized virus panels in neutralization and vaccine studies is also discussed. Srivastava2005 (antibody binding site, neutralization, vaccine antigen design, variant cross-reactivity, review, structure)
17b: This Ab bound with an intermediate affinity to gp120IIIb, it did not prevent uptake of gp120 by APCs, and had no inhibitory effect on gp120 antigen presentation by MHC class II. 17b disassociated from gp120 at acidic pH. Lysosomal enzyme digestion of gp120 treated with 17b yielded fragmentation similar to that of gp120 alone, and digestion rate was intermediate, between the rapid digestion of gp120 alone and the slow digestion of gp120 in complex with high-affinity Ab5145A. It is thus concluded that CD4i Ab 17b does not have an inhibitory effect on gp120 processing and presentation. Tuen2005 (antibody interactions, binding affinity)
17b: Ab neutralization of viruses with mixtures of neutralization-sensitive and neutralization-resistant envelope glycoproteins was measured. It was concluded that binding of a single Ab molecule is sufficient to inactivate function of an HIV-1 glycoprotein trimer. The inhibitory effect of the Ab was similar for neutralization-resistant and -sensitive viruses indicating that the major determinant of neutralization potency of an Ab is the efficiency with which it binds to the trimer. It was also indicated that each functional trimer on the virus surface supports HIV-1 entry independently, meaning that every trimer on the viral surface must be bound by an Ab for neutralization of the virus to be achieved. Yang2005b (neutralization)
17b: A substantial fraction of soluble envelope glycoprotein trimers contained inter-subunit disulfide bonds. Reduction of these disulfide bonds decreased binding of 17b to the glycoprotein, indicating that the inter-S-S bonds contribute to the exposure of the CD4-induced region. Yuan2005 (antibody binding site)
17b: Conformation of two gp120 constructs, gp120 bound to CD4D12 (the first two domains of human CD4), and gp120 bound to M9 (a 27-residue CD4 analog), was characterized by binding assays with Ab b17 in the presence or absence of soluble CD4D12. JRFL gp120 alone did not bind to b17 in the absence of CD4D12 but did bind in the presence of CD4D12. The gp120-CD4D12 construct bound to b17 in the absence of soluble CD4D12, and no enhancement in binding was observed when soluble CD4D12 was present, suggesting that all of the single chain was properly folded in the CD4i conformation. gp120-M9 construct also bound to 17b but with much lower affinity, and the binding was enhanced with presence of soluble CD4D12. This suggested that gp120-M9 single chain may contain both molecules where gp120 is bound to M9 in the CD4i conformation, and molecules resembling free gp120. Varadarajan2005 (antibody binding site, kinetics, binding affinity)
17b: A reverse capture assay was developed to assess what kind of human MAbs were produced in EBV B-cell transformation assays performed on PBMC sampled at different time-points from three HIV-1 infected patients on HAART. The reverse capture assay was validated by the solid phase MAbs that could not capture biotin-MAbs of the same or overlapping specificity when reacted with patient virus envelope glycoproteins preincubated with or without sCD4. Reverse capture assay showed that the produced Abs from the patients were able to block binding of biotin-labeled 17b, indicating presence of CD4i Abs. These were the most frequently produced Abs from all three patients, suggesting that CD4i epitopes are much more immunogenic than previously appreciated. Robinson2005 (assay or method development, HAART, ART)
17b: This review summarizes data on 447-52D and 2219 crystallographic structures when bound to V3 peptides and their corresponding neutralization capabilities. 17b, like 447-52D and like other HIV-1 neutralizing Abs, was shown to have long CDR H3 loop, which is suggested to help Abs access recessed binding sites on the virus. Stanfield2005 (antibody binding site, review, structure)
17b: A T-cell line adapted strain (TCLA) of CRF01_AE primary isolate DA5 (PI) was more neutralization sensitive to 17b than the primary isolate. Mutant virus derived from the CRF01_AE PI strain, that lacked N-linked glycosylation at position 197 in the C2 region of gp120, was significantly more sensitive to neutralization by 17b then the PI strain. Deglycosylated subtype B mutants at positions 197 and 234 were slightly more neutralizable by 17b. Teeraputon2005 (antibody binding site, neutralization, subtype comparisons)
17b: Macaques were immunized with SF162gp140, ΔV2gp140, ΔV2ΔV3gp140 and ΔV3gp140 constructs and their antibody responses were compared to the broadly reactive NAb responses in a macaque infected with SHIV SF162P4, and with pooled sera from humans infected with heterologous HIV-1 isolates (HIVIG). 17b bound to SF162gp140 and ΔV3gp140 more efficiently than to ΔV2gp140 and ΔV2ΔV3gp140. The neutralization of SF162 by 17b was enhanced in a concentration-dependent manner by pre-incubation with sCD4. Derby2006 (antibody binding site, neutralization)
17b: This Ab bound to the Fc-gp120 construct, but only weakly to the chimeras lacking the V3 loop. sCD4 restored high affinity binding to all constructs. Binley2006 (binding affinity)
17b: A fusion protein (FLSC R/T-IgG1) that targets CCR5 was expressed from a synthetic gene linking a single chain gp120-CD4 complex containing an R5 gp120 sequence with the hinge-Ch2-Ch3 portion of human IgG1. Binding of this protein to the CCR5 co-receptor was inhibited by MAb 17b in a dose-dependent manner. The fusion protein did not activate the co-receptor by binding, and it potently neutralized primary R5 HIV-1. Vu2006 (co-receptor)
17b: Cloned Envs (clades A, B, C, D, F1, CRF01_AE, CRF02_AG, CRF06_cpx and CRF11_cpx) derived from donors either with or without broadly cross-reactive neutralizing antibodies were shown to be of comparable susceptibility to neutralization by 17b. Cham2006 (neutralization, variant cross-reactivity, subtype comparisons)
17b: Neutralization of HIV-1 primary isolates from clade B by different formats of 17b was determined in cells expressing high or low surface concentrations of CD4 and CCR5 receptors. CD4 cell surface concentration had no effect on the inhibitory activity of this Ab while the CCR5 surface concentration had a significant effect decreasing the 50% inhibitory concentration of 17b in cell lines with low CCR5. Choudhry2006 (co-receptor, neutralization, variant cross-reactivity)
1.7b: This Ab did not inhibit HIV-1 BaL replication in macrophages or in PHA-stimulated PBMCs. Holl2006 (neutralization, dendritic cells)
17b: 17b was used as a negative control to test CDR3 tyrosine sulfation of MAbs 47e, 412d, CM51, E51, C12 and Sb1, since its CDR3 tyrosines are buried. As expected, 17b did not incorporate sulfates while the other MAbs did. Thus, the expression of 17b, or its binding to gp120 bound to CD4-Ig, was not affected by sulfation-inhibition. In addition, 17b was used as a positive control to test whether MAbs 47e, 412d, E51, Sc1 and C12 are CD4i Abs. Binding efficiency of all MAbs to ADA gp120 was doubled in the presence of CD4, showing that they are CD4-induced. scFv 17b was shown to efficiently bind to gp120 of three R5 isolates and to the HXBc2 X4 isolate. Neutralization assays showed that 17b was less efficient at neutralizing primary R5 and R5X4 isolates than MAbs 412d and E51, however, it was more efficient at neutralizing X4 isolates than these MAbs. Choe2003 (antibody binding site, neutralization)
17b: The CDR3 regions of CD4i Abs (E51, 412d, 17b, C12 and 47e) were cloned onto human IgG1 and tested for their ability to inhibit CCR5 binding. Only E51 successfully immunoprecipitated gp120. Dorfman2006 (co-receptor)
17b: The gp140δCFI protein of CON-S M group consensus protein and gp140CFI and gp140CF proteins of CON6 and WT viruses from HIV-1 subtypes A, B and C were expressed in recombinant vaccinia viruses and tested as immunogens in guinea pigs. Both CD4 induced and A32 induced 17b was shown to bind specifically to all recombinant proteins except for the gp140δFI derived from subtype C virus. This Ab also bound specifically to one of the two tested subtype B gp120 proteins. The specific binding of his Ab to CON-S indicated that its conformational epitope was intact. Liao2006 (antibody binding site, vaccine antigen design, subtype comparisons)
17b: The small molecule HIV-1 entry inhibitor IC9564 significantly enhanced binding of 17b Ab to gp120 on cell surface and on viral particles. The binding was independent of the presence of soluble CD4 suggesting that IC9564 induces conformational change in gp120 that exposes the concealed 17b epitope. Significant increase in neutralizing activity of 17b in the presence of IC9564 was observed for NLDH120 and NL4-3 virus strains. In contrast to CD4, IC9564 does not induce a conformational change in gp41, and inhibits CD4-induced gp41 conformational changes. Huang2007 (antibody binding site)
17b: SOSIP Env proteins are modified by the introduction of a disulfide bond between gp120 and gp41 (SOS), and an I559P (IP) substitution in gp41, and form trimers. The KNH1144 subtype A virus formed more stable trimers than did the prototype subtype B SOSIP Env, JRFL. The stability of gp140 trimers was increased for JR-FL and Ba-L SOSIP proteins by substituting the five amino acid residues in the N-terminal region of gp41 with corresponding residues from KNH1144 virus. b12, 2G12, 2F5, 4E10 and CD4-IgG2 all bound similarly to the WT and to the stabilized JRFL SOSIP timers, suggesting that the trimer-stabilizing substitutions do not impair the overall antigenic structure of gp140 trimers. 17b binding was induced similarly by sCD4 in the WT and stabilized forms. Non-neutralizing MAbs PA-1 and b6 bound less efficiently to the stabilized trimer. Dey2007 (vaccine antigen design)
17b: This Ab was found to be able to bind to a highly stable trimeric rgp140 derived from a HIV-1 subtype D isolate containing intermonomer V3-derived disulfide bonds and lacking gp120/gp41 cleavage. Protein disulfide isomerase treatment of rgp120 and rgp140 was found to severely inhibit binding of 17b, suggesting a structural need for V3-derived disulfide bonds in coreceptor binding. gp140 binding to 17b was 2-fold enhanced with by sCD4, indicating the proteolytically immature protein was able to undergo CD4i conformational changes. Billington2007 (antibody binding site, co-receptor, vaccine antigen design)
17b: Four consensus B Env constructs: full length gp160, uncleaved gp160, truncated gp145, and N-linked glycosylation-site deleted (gp160-201N/S) were compared. All were packaged into virions, and all but the fusion defective uncleaved version mediated infection using the CCR5 co-receptor. CD4 inducible MAbs 17b and E51 were tested for the ability to neutralize the various forms of Con B; as anticipated gp160 and gp145 were not neutralized by these two MAbs, but the gp160-201N/S mutant was neutralized with IC50 values of 10 ug/ml, suggesting increased formation and/or exposure of the co-receptor binding site. The poorly infectious clone WITO4160.27 was also somewhat susceptible to neutralization by these clones. Kothe2007 (vaccine antigen design, variant cross-reactivity)
17b: Antigens were designed to attempt to target immune responses toward the IgG1b12 epitope, while minimizing antibody responses to less desirable epitopes. One construct had a series of substitutions near the CD4 binding site (GDMR), the other had 7 additional glycans (mCHO). The 2 constructs did not elicit b12-like neutralizing antibodies, but both antigens successfully dampened other responses that were intended to be dampened while not obscuring b12 binding. CD4i MAbs (48d, 17b) did not bind to either GDMR or mCHO even with sCD4. Selvarajah2005 (vaccine antigen design, vaccine-induced immune responses)
17b: The HIV-1 Bori-15 variant was adapted from the Bori isolate for replication microglial cells. Bori-15 had increased replication in microglial cells and a robust syncytium-forming phenotype, ability to use low levels of CD4 for infection, and increased sensitivity to neutralization by sCD4 and 17b. Four amino acid changes in gp120 V1-V2 were responsible for this change. Protein functionality and integrity of soluble, monomeric gp120-molecules derived from parental HIV-1 Bori and microglia-adapted HIV-1 Bori-15 was assessed in ELISA binding assays using F105, IgG1b12, 17b and 48d, 2G12 and 447-52D. Association rates of sCD4 and 17b were not changed, but dissociation rates were 3-fold slower for sCD4 and 14-fold slower for 17b. Martin-Garcia2005
17b: The epitope for the MAb D19 is conserved and embedded in V3. D19 is unique in that for R5 viruses, it was cryptic and did not bind without exposure to sCD4, and for X4 and R5X4 isolates it was constitutively exposed. D19b is unique among CD4i antibodies in that it binds to the V3 loop. CD4i MAbs 17b and 48d were used as controls for CD4i characterization; in contrast to D19, other CD4i MAbs bind to the conserved bridging sheet and do not differentiate between R5 and X4 using strains. 17b, like D19, was able to neutralize the BaL isolate only in combination with sCD4. Lusso2005
17b: IgG antibody phage display libraries were created from HIV-1+ individuals after pre-selection of PBMC with gp120, as an alternative to using bone marrow for generating libraries. 17b was among a set of Abs used for competition studies to define the binding sites of the newly isolated MAbs, representing a MAb with a CD4i epitope. Koefoed2005
17b: Called 1.7B. Of 35 Env-specific MAbs tested, only 2F5, 4E10, IgG1b12, and two CD4BS adjacent MAbs (A32 and 1.4G) and gp41 MAbs (2.2B and KU32) had binding patterns suggesting polyspecific autoreactivity, and similar reactivities may be difficult to induce with vaccines because of elimination of such autoreactivity. 1.7B has no indication of polyspecific autoreactivity. Haynes2005 (antibody binding site)
17b: By adding N-linked glycosylation sites to gp120, epitope masking of non-neutralizing epitopes can be achieved leaving the IgG1b12 binding site intact. This concept was originally tested with the addition of four glycosylation sites, but binding to b12 was reduced. It was modified here to exclude the C1 N-terminal region, and to include only three additional glycosylation sites. This modified protein retains full b12 binding affinity and it masks other potentially competing epitopes, and does not bind to 21 other MAbs to 7 epitopes on gp120, including 17b. Pantophlet2004 (vaccine antigen design)
17b: 17b is known to be comprised of elements from four discontinuous beta strands. Using 17b MAb to select peptides from a combinatorial library, and analyzing the peptides using a novel discontinuous epitope reconstruction program, enabled epitope prediction. Segments of gp120 were reconstructed as an antigenic protein mimetic recognized by 17b. Comparisons then were made with a similar prediction of contact residues for CG10, a CD4i MAb that competes with 17b, but has a distinct binding site. Database note: First author "Enshell-Seijffers" is also found as "EnshellSeijffers" on annotated papers in this database. Enshell-Seijffers2003 (antibody binding site, mimotopes, computational epitope prediction)
17b: V1V2 was determined to be the region that conferred the neutralization phenotype differences between two R5-tropic primary HIV-1 isolates, JRFL and SF162. JRFL is resistant to neutralization by many sera and MAbs, while SF162 is sensitive. All MAbs tested, anti-V3, -V2, -CD4BS, and -CD4i, (except the broadly neutralizing MAbs IgG1b12, 2F5, and 2G12 which neutralized both strains), neutralized the SF162 pseudotype but not JRFL, and chimeras that exchanged the V1V2 loops transferred the neutralization phenotype. Three CD4i MAbs were tested; all preferentially neutralized SF162, and JRFL became neutralization sensitive to CD4i Abs if the SF162 V1V2 loop was exchanged. Pinter2004 (variant cross-reactivity)
17b: A set of HIV-1 chimeras that altered V3 net charge and glycosylation patterns in V1V2 and V3, involving inserting V1V2 loops from a late stage primary isolate taken after the R5 to X4 switch, were studied with regard to phenotype, co-receptor usage, and MAb neutralization. The loops were cloned into a HXB2 envelope with a LAI viral backbone. It was observed that the addition of the late-stage isolate V1V2 region and the loss of V3-linked glycosylation site in the context of high positive charge gave an X4 phenotype. R5X4, R5, and X4 viruses were generated, and sCD4, 2G12 and b12 neutralization resistance patterns were modified by addition of the late stage V1V2, glycosylation changes, and charge in concert, while neutralization by 2F5 was unaffected. 15e, 17b, and 48d could not neutralize any of the variants tested. Nabatov2004 (antibody binding site, co-receptor)
17b: Sera from two HIV+ people and a panel of MAbs were used to explore susceptibility to neutralization in the presence or absence of glycans within or adjacent to the V3 loop and within the C2, C4 and V5 regions of HIV-1 SF162 env gp120. The loss of the glycan within the V3 loop (GM299 V3) and two sites adjacent to V3, C2 (GM292 C2) and (GM329 C3), increased neutralization susceptibility to CD4i FAb X5, but each of the glycan mutants and SF162 were refractive to neutralization with 48d and 17b. The loss of sites in C4 (GM438 C4), or V5 (GM454 V5) did not increase neutralization susceptibility to FAb X5. V3 glycans tended to shield V3 loop, CD4 and co-receptor MAb binding sites, while C4 and V5 glycans shielded V3 loop, CD4, gp41 but not co-receptor MAb binding sites. Selective removal of glycans from a vaccine candidate may enable greater access to neutralization susceptible epitopes. McCaffrey2004 (antibody binding site, vaccine antigen design)
17b: The role of serine proteases on HIV infection was explored. Trypsin decreased the binding of most Env MAb tested and diminished cell fusion of H9 cells infected with HIV-1 LAI virus (H9/IIIB) to MAGI cells. In contrast, thrombin increased the binding of MAbs to gp120 epitopes near the CD4 and CCR5 binding sites, and increased cell fusion. Binding of 17b was decreased by trypsin, but increased by thrombin. Thrombin may increase HIV-induced cell fusion in blood by causing a conformational activating shift in gp120. Ling2004 (antibody binding site)
17b: A pseudotyping assay showed that an X4 V3 loop peptide could enhance infectivity of X4 virus, R5 and R5X4 V3 loops peptides could enhance infectivity of an R5 virus, and R5X4 peptides could enhance infectivity of an R5X4 virus. Neither R5 nor R5X4 peptides influenced binding of CD4BS MAbs F105 and Ig1Gb12, but did increase binding of CD4i MAb 17b. Ling2002 (antibody binding site, co-receptor)
17b: A32-rgp120 complexes opened up the CCR5 co-receptor binding site, but did not induce neutralizing antibodies with greater breadth among B subtype isolates than did uncomplexed rgp120 in vaccinated guinea pigs. 17b was used as a control to show A32-bound rgp120 had enhanced binding to this CD4-inducible MAb. Liao2004 (vaccine antigen design)
17b: The peptide 12p1 (RINNIPWSEAMM) inhibits direct binding of YU2 gp120 or Env trimer to CD4, CCR5 and MAb 17b in a concentration-dependent allosteric manner. 12p1 is thought to bind to unbound gp120 near the CD4 binding site, with a 1:1 stoichiometry. 12p1 also inhibited MAb F105 binding presumably because F105 favors an unactivated conformation, but not MAbs 2G12 or b12. The 1:1 stoichiometry, the fact that the peptide binding site is accessible on the trimer, the non-CD4 like aspect of the binding, and an ability to inhibit viral infection in cell cultures make it a promising lead for therapeutic design. Biorn2004
17b: Vaccination of a gp120-CD4 fusion complex in six transgenic XMG2 XenoMouse mice that produce human IgG2 with K light chain did not produce any neutralizing antibodies. 36/39 MAbs derived from one of these mice were in one of two competition groups that were conformational and specific for the complex, suggesting this chimeric vaccine may be of little value, as immunodominant responses recognized epitopes not present in native Env. MAbs from the two CD4-gp120 complex-specific competition groups did not compete with MAbs with known targets on HIV-1 gp120, but their binding was enhanced by binding of 17b. He2003
17b: Using a cell-fusion system, it was found CD4i antibodies 17b, 48d, and CG10 reacted faintly with Env expressing HeLA cells even in the absence of sCD4 or CD4 expressing target cells. Reactivity increased after sCD4 addition, but not after CD4 expressing target cell addition, and binding was not increased at the cell-to-cell CD4-Env interface. This suggests the CD4i co-receptor binding domain is largely blocked at the cell-fusion interface, and so CD4i antibodies would not be able access this site and neutralize cell-mediated viral entry. Finnegan2001
17b: This review summarizes MAbs directed to HIV-1 Env. There are six CD4 inducible MAbs and Fabs in the database. The MAb forms neutralize TCLA strains only, but the smaller Fabs and scFv fragments can neutralize primary isolates. Gorny2003 (antibody binding site, review)
17b: A gp120 molecule was designed to focus the immune response onto the IgG1b12 epitope. Ala substitutions that enhance the binding of IgG1b12 and reduce the binding of non-neutralizing MAbs were combined with additional N-linked glycosylation site sequons inhibiting binding of non-neutralizing MAbs; b12 bound to the mutated gp120. C1 and C5 were also removed, but this compromised b12 binding. Pantophlet2003b (vaccine antigen design)
17b: scFv 4KG5 reacts with a conformational epitope. Of a panel of MAbs tested, only NAb b12 enhanced 4KG5 binding to gp120. MAbs to the V2 loop, V3 loop, V3-C4 region, and CD4BS diminished binding, while MAbs directed against C1, CD4i, C5 regions didn't impact 4KG5 binding. These results suggest that the orientation or dynamics of the V1/V2 and V3 loops restricts CD4BS access on the envelope spike, and IgG1b12 can uniquely remain unaffected. This is a CD4i MAb that had no impact on 4KG5 binding. Zwick2003a (antibody interactions)
17b: The HIV-1 primary isolate DH012 has preserved the epitopes for the MAbs IgG1b12, 2G12, 17b, however natural DH012 infection in chimpanzees and DH012 gp120 vaccination in guinea pigs does not give rise to Abs against these epitopes. Zhu2003 (vaccine-induced immune responses)
17b: Env genes derived from uncultured brain biopsy samples from four HIV-1 infected patients with late-stage AIDS were compared to env genes from PBMC samples. Brain isolates did not differ in the total number or positions of N-glycosylation sites, patterns of coreceptor usage, or ability to be recognized by gp160 and gp41 MAbs. 17b recognized most variants, some from each of the four individuals, by gp120 immunoprecipitation. Ohagen2003 (brain/CSF, variant cross-reactivity)
17b: Thermodynamics of binding to gp120 was measured using isothermal titration calorimetry for sCD4, 17b, b12, 48d, F105, 2G12 and C11 to intact YU2 and the HXBc2 core. The free energy of binding was similar. Enthalpy and entropy changes were divergent, but compensated. Not only CD4 but MAb ligands induced thermodynamic changes in gp120 that were independent of whether the core or the full gp120 protein was used. Non-neutralizing CD4BS and CD4i MAbs (17b, 48d, 1.5e, b6, F105 and F91) had large entropy contributions to free energy (mean: 26.1 kcal/mol) of binding to the gp120 monomer, but the potent CD4BS neutralizing MAb b6 had a much smaller value of 5.7 kcal/mol. The high values suggest surface burial or protein folding an ordering of amino acids. These results suggest that while the trimeric Env complex has four surfaces, a non-neutralizing face (occluded on the oligomer), a variable face, a neutralizing face and a silent face (protected by carbohydrate masking), gp120 monomers further protect receptor binding sites by conformational or entropic masking, requiring a large energy handicap for Ab binding not faced by other anti-gp120 Abs. Kwong2002 (antibody binding site)
17b: This paper describes the generation of CD4i MAb E51, that like CD4i MAb 17b, blocks CCR5 binding to sCD4-bound gp120. E51 has more cross-neutralizing potency than other prototype CD4i MAbs (17b) for B and C clade isolates. E51 and 17b both neutralized HIV-1 clade B strains HXBc2 and ADA, while JR-FL and 89.6 were only neutralized by E51, not 17b. Clade C strains MCGP1.3 and SA32 were both inhibited by 17b and E51, but E51 was more potent against SA32. The substitutions E381R, F383S, R419D I420R, K421D, Q422L, I423S, and Y435S (HXB2 numbering) all severely reduce 17b and E51 binding. All but I423S also diminish CCR5 binding by more than 50%. The mutation F383S also inhibits sCD4 binding and F105 binding, and K421D inhibits F105 binding, but not sCD4. Xiang2003 (antibody binding site, variant cross-reactivity, subtype comparisons)
17b: This study shows the fragments of CD4i MAbs are better able to neutralize virus than whole IgG. Neutralization of HIV-1 R5 isolates JRFL, JR-CSF and ADA by CD4i MAbs X5, 17b, and 48d decreased with increased molecule size, the neutralizing potency of single-chain Fv (scFv) > than Fab fragments > whole Ab molecules. (With the exception of IgG 48d neutralization of HIV-1 ADA.) HIV-1 X4 isolates 89.6 and HxB2 are both relatively sensitive even to the larger IgG version. R5X4 isolate neutralization was dependent on the isolate and co-receptor usage. The CD4i MAb fragments neutralize HIV-1 subsequent to CD4 binding. The CD4i MAbs bind near the co-receptor binding sites on gp120. Co-receptors bind to the conserved beta19 strand and part of the V3 loop, regions that are masked by the V1V2 loops in the CD4-unbound state. When CD4 is bound, the co-receptor site is exposed near the membrane surface where it would be optimally accessible to co-receptors, and the smaller versions of the molecules are better able to overcome the steric hindrance. Labrijn2003 (antibody binding site, co-receptor, variant cross-reactivity)
17b: Anti-gp41 MAbs were tested in a cell-cell fusion system to investigate the antigenic changes in gp41 during binding and fusion. Cluster I and Cluster II MAbs required CD4 expression on HIV HXB2 Env expressing HeLa target cells, but not the CXCR4 co-receptor, binding to a fusion intermediate. 17b was used to demonstrate that the Cluster I and II MAbs bound to gp120/gp41 complexes, not to gp41 after shedding of gp120. Finnegan2002
17b: A sCD4-17b single chain chimera was made that can bind to the CD4 binding site, then bind and block co-receptor interaction. This chimeric protein is a very potent neutralizing agent, more potent than IgG1b12, 2G12 or 2F5 against Ba-L infection of CCR5-MAGI cells. It has potential for prophylaxis or therapy. It neutralized 5/6 R5 and X4 strains from the B clade, but was only moderately protective against a D clade isolate, and did not neutralize clade A, C, E, and F isolates. Dey2003 (co-receptor, immunoprophylaxis, variant cross-reactivity, immunotherapy, subtype comparisons)
17b: Called 1.7b. The MAb B4e8 binds to the base of the V3 loop, neutralizes multiple primary isolates and was studied for interaction with other MAbs. B4e8 enhanced binding of CD4i MAbs 4.8d, 1.7b, and A1g8 to R5X4 virus 92HT593, but only of 48d to the R5 virus 92US660, and there was only a modest impact of the combination of B4e8 and CD4i MAbs on neutralization. Cavacini2003 (antibody interactions, co-receptor)
17b: This study examined antibody interactions, binding and neutralization with a B clade R5 isolate (92US660) and R5X4 isolate (92HT593). Abs generally bound and neutralized the R5X4 isolate better than the R5 isolate. Anti-V3 MAb B4a1 increased binding of CD4i MAbs 48d, 17b and A1g8, but only A1g8 binding was increased by B4a1 to the R5 isolate. Additive effects on neutralization of the R5X4 isolate with B4a1 and CD4i MAbs was observed, presumably due to increased exposure of the CD4i binding site, but not for the R5 isolate. Anti-gp41 MAb F240 had a synergistic effect on neutralization with CD4i MAbs 48d and 17b, but not with A1g8 for the R5X4 virus. Cavacini2002 (antibody interactions, co-receptor, variant cross-reactivity)
17b: The SOS mutant envelope protein introduces a covalent disulfide bond between gp120 surface and gp41 transmembrane proteins into the R5 isolate JR-FL by adding cysteines at residues 501 and 605. Pseudovirions bearing this protein bind to CD4 and co-receptor bearing cells, but do not fuse until treatment with a reducing agent, and are arrested prior to fusion after CD4 and co-receptor engagement. CD4i Abs 17b and X5 were weakly neutralizing in all formats, WT, SOS, and when added postbinding. Binley2003 (vaccine antigen design)
17b: NIH AIDS Research and Reference Reagent Program: 4091.
17b: The two N-terminal domains of CD4, termed D1 and D2, when expressed in the absence of the remaining domains of CD4 retain the capacity to bind to gp120---coding sequences of D1D2 and Igαtp were fused to create a large, multivalent rec protein D1D2Igαtp, which, unlike CD4, does not enhance infection at sub-optimal concentrations---the MAb 17b can also enhance viral replication at sub-optimal concentrations, but D1D2-Igα inhibited the 17b enhancement of two primary isolates. Arthos2002 (variant cross-reactivity)
17b: A rare mutation in the neutralization sensitive R2-strain in the proximal limb of the V3 region caused Env to become sensitive to neutralization by MAbs directed against the CD4 binding site (CD4BS), CD4-induced (CD4i) epitopes, soluble CD4 (sCD4), and HNS2, a broadly neutralizing sera -- 2/12 anti-V3 MAbs tested (19b and 694/98-D) neutralized R2, as did 2/3 anti-CD4BS MAbs (15e and IgG1b12), 2/2 CD4i MAbs (17b and 4.8D), and 2G12 and 2F5 -- thus multiple epitopes on R2 are functional targets for neutralization and the neutralization sensitivity profile of R2 is intermediate between the highly sensitive MN-TCLA strain and the typically resistant MN-primary strain. Zhang2002
17b: gp120 mutants were used to define the CXCR4 binding site using CXCR4 displayed on paramagnetic proteoliposomes (PMPLs) to reduce non-specific gp120 binding---basic residues in the V3 loop and the β19 strand (RIKQ, positions 419-422) were involved, and deletion of the V1-V2 loops allowed CD4-independent CXCR4 binding---MAbs 17b (CD4i) and F105 (CD4BS) were used to study conformational changes in the mutants---the affinity of ΔV1 and ΔV1-V2 for 17b was dramatically increased and no longer inducible in the presence of sCD4---V3 mutants R298A and R327A were not recognized by 17b except in the presence of sCD4---mutations in the β19 strand dramatically reduced 17b affinity in the presence or absence of sCD4, consistent with known 17b contact residues in this region. Basmaciogullar2002
17b: HIV-1 gp160ΔCT (cytoplasmic tail-deleted) proteoliposomes (PLs) containing native, trimeric envelope glycoproteins from R5 strains YU2 and JRFL, and X4 strain HXBc2, were made in a physiologic membrane setting as candidate immunogens for HIV vaccines---2F5 bound to gp160ΔCT with a reconstituted membrane ten-fold better than the same protein on beads---anti-CD4BS MAbs IgG1b12 and F105, A32 (C1-C4), C11 (C1-C5), and 39F (V3) MAbs bound gp160ΔCT PLs indistinguishably from gp160ΔCT expressed on the cell surface---non-neutralizing MAbs C11 and A32 bound with lower affinity than NAb IgG1b12---the MAb 17b was sCD4 inducible on gp160ΔCT PL. Grundner2002 (vaccine antigen design)
17b: Truncation of the gp41 cytoplasmic domain of X4, R5, and X4R5 viruses forces a conformation that more closely resembles the CD4 bound state of the external Envelope, enhancing binding of CD4i MAbs 17b and 48d and of CD4BS MAbs F105, b12, and in most cases of glycosylation site dependent MAb 2G12 and the anti-gp41 MAb 246D -- in contrast, binding of the anti-V2 MAb 697D and the anti-V3 MAb 694/98D were not affected -- viruses bearing the truncation were more sensitive to neutralization by MAbs 48d, b12, and 2G12 -- the anti-C5 MAb 1331A was used to track levels of cell surface expression of the mutated proteins. EdwardsBH2002 (vaccine-induced immune responses)
17b: Five CD4i MAbs were studied, 17b, 48d and three new MAbs derived by Epstein-Barr virus transformation of PBMC from an HIV+ long term non-progressor -- 23e and 21c were converted to hybridomas to increase Ab production -- all compete with the well-characterized 17b CD4i MAb in an ELISA antigen capture assay -- critical binding residues are mapped and the CD4i MAb epitopes were distinct but share a common element near isoleucine 420, also important for CCR5 binding, and all five can block CCR5 binding to a sCD4-gp120 complex -- the MAb 48d has the epitope most similar to the CCR5 binding site. Xiang2002b (antibody binding site)
17b: A series of mutational changes were introduced into the YU2 gp120 that favored different conformations -- 375 S/W seems to favor a conformation of gp120 closer to the CD4-bound state, and is readily bound by sCD4 and CD4i MAbs (17b, 48d, 49e, 21c and 23e) but binding of anti-CD4BS MAbs (F105, 15e, IgG1b12, 21h and F91 was markedly reduced -- IgG1b12 failed to neutralize this mutant, while neutralization by 2G12 was enhanced -- 2F5 did not neutralize either WT or mutant, probably due to polymorphism in the YU2 epitope -- another mutant, 423 I/P, disrupted the gp120 bridging sheet, favored a different conformation and did not bind CD4, CCR5, or CD4i antibodies, but did bind to CD4BS MAbs. Xiang2002 (variant cross-reactivity)
17b: CD4 residue Phe43 significantly contributes to the affinity of CD4-gp120 interactions -- despite decreased affinities for gp120, CD4 proteins and CD4-mimetic peptides lacking a Phe side-chain enhance binding of gp120 to 17b in a manner similar to Phe-bearing ligands indicating the Phe42 interaction is not critical for CD4-induced conformational changes in gp120. Dowd2002
17b: Uncleaved soluble gp140 (YU2 strain, R5 primary isolate) can be stabilized in an oligomer by fusion with a C-term trimeric GCN4 motif or using a T4 trimeric motif derived from T4 bacteriophage fibritin---stabilized oligomer gp140Δ683(-FT) showed strong preferential recognition by NAbs IgG1b12 and 2G12 relative to the gp120 monomer, in contrast to poorly neutralizing MAbs F105, F91, 17b, 48d, and 39F which showed reduced levels of binding, and C11, A32, and 30D which did not bind the stabilized oligomer. Yang2002
17b: Ab binding characteristics of SOS gp140 were tested using SPR and RIPA -- SOS gp140 is gp120-gp41 bound by a disulfide bond -- NAbs 2G12, 2F5, IgG1b12, CD4 inducible 17b, and 19b bound to SOS gp140 better than uncleaved gp140 (gp140unc) and gp120 -- non-neutralizing MAbs 2.2B (binds to gp41 in gp140unc) and 23A (binds gp120) did not bind SOS gp140. Schulke2002 (vaccine antigen design)
17b: The fusion process was slowed by using a suboptimal temperature (31.5 C) to re-evaluate the potential of Abs targeting fusion intermediates to block HIV entry -- preincubation of E/T cells at 31.5 C enabled polyclonal anti-N-HR Ab and anti-six-helix bundle Abs to inhibit fusion, indicating six-helix bundles form prior to fusion -- the preincubation 31.5 C step did not alter the inhibitory activity of neutralizing Abs anti-gp41 2F5, or anti-gp120 2G12, IG1b12, 48d, and 17b. GoldingH2002
17b: Oligomeric gp140 (o-gp140) derived from R5 primary isolate US4 was characterized for use as a vaccine reagent -- antigen capture ELISA was used to compare the antigenicity of gp120 and o-gp140 using a panel of well characterized MAbs -- 17b recognized both gp120 monomer and o-gp140. Srivastava2002
17b: Structural aspects of the interaction of neutralizing Abs with HIV-1 Env are reviewed -- Env essentially has three faces, one is largely inaccessible on the native trimer, and two that exposed but have low immunogenicity on primary viruses -- neutralization is suggested to occur by inhibition of the interaction between gp120 and the target cell membrane receptors as a result of steric hindrance and it is noted that the attachment of approximately 70 IgG molecules per virion is required for neutralization, which is equivalent to about one IgG molecule per spike -- the 2G12, 17b and b12 epitopes are discussed in detail -- the 17b epitope is masked prior to CD4 binding by the V1-V2 loop and in contrast to sCD4, the binding of cell surface CD4 to virus does not appear to make the epitope accessible to binding by 17b to allow neutralization. Poignard2001 (antibody binding site, review)
17b: 17b binds to a CD4 inducible epitope which partially overlaps the CCR5 binding site -- JRFL, YU2, 89.6, and HXB2 and their C1-, V1/V2-, C5 -deletion mutants were used to study how 17b binding affects gp120-CD4 interactions -- 17b reduced CD4-gp120 interactions by decreasing the on-rate and increasing the off-rate of sCD4, while enhanced binding of sCD4 binding was observed for the 17b-bound, V1/V2 deleted gp120s -- 17b was considered to be a surrogate for CCR5, and the authors suggest that 17b binding may shift V1/V2 into a position that interferes with CD4 binding, forcing a release. Zhang2001a (antibody binding site, kinetics)
17b: Abs against the V3 loop (50.1, 58.2, 59.1, 257-D, 268-D, 447-52D), CD4BS (IgG1b12, 559-64D, F105), CD4i (17b), and to gp41 (2F5, F240) each showed similar binding efficiency to Env derived from related pairs of primary and TCLA lines (primary: 168P and 320SI, and TCLA: 168C and 320SI-C3.3), but the TCLA lines were much more susceptible to neutralization suggesting that the change in TCLA lines that make them more susceptible to NAbs alters some step after binding -- 17b bound at somewhat greater levels to 168C than to 168P, but this is not a general feature of 17b binding to primary versus TCLA strains. York2001 (variant cross-reactivity)
17b: Mutations in two glycosylation sites in the V2 region of HIV-1 ADA at positions 190 and 197 (187 DNTSYRLINCNTS 199) cause the virus to become CD4-independent and able to enter cells through CCR5 alone---these same mutations tended to increase the neutralization sensitivity of the virus, including to 17b---only the CD4i antibodies 17b and 48d showed an increased affinity of the CD4 independent viruses relative to wild-type. Kolchinsky2001 (antibody binding site, variant cross-reactivity)
SHIV-HXBc2 is a neutralization sensitive non-pathogenic virus, and several in vivo passages through monkey's yielded highly pathogenic SHIV KU-1 -- HXBc2 and the KU-1 clone HXBc2P3.2 differ in 12 amino acids in gp160 -- substitutions in both gp120 and gp41 reduced the ability of sCD4, IgG1b12, F105 and AG1121 to Env achieve saturation and full occupancy, and neutralize KU-1 -- 17b and 2F5 also bound less efficiently to HXBc2P3.2, although 2G12 was able to bind both comparably. Si2001 (variant cross-reactivity)
17b: Mutagenesis defines Ile-420, Lys-421, Gln-422, Pro-438, and Gly-441 to be important residues for CCR5 binding -- these positions are located on two strands that connect the gp120 bridging sheet and outer domain, suggesting a mechanism for conformational shifts induced by CD4 binding to facilitate CCR5 binding. Rizzuto2000 (antibody binding site)
17b: A combination of gp41 fusion with the GNC4 trimeric sequences and disruption of the YU2 gp120-gp41 cleavage site resulted in stable gp140 trimers (gp140-GNC4) that preserve and expose some neutralizing epitopes while occluding some non-neutralizing epitopes -- CD4BS MAbs (F105 and F91) and CD4i (17b and 48d) recognized gp140-GNC4 as well as gp120 or gp140 -- non-neutralizing MAbs C11, A32, 522-149, M90, and #45 bound to the gp140-GNC4 glycoprotein at reduced levels compared to gp120 -- MAbs directed at the extreme termini of gp120 C1 (135/9 and 133/290) and C5 (CRA-1 and M91) bound efficiently to gp140-GNC4. Yang2000 (vaccine antigen design)
17b: Soluble gp140 derived from SF162, a neutralization-resistant primary isolate, and SF162AV2 a neutralization-susceptible isolate with 30 amino acids deleted from the V2 loop, were generated with or without the gp120-gp41 cleavage site intact -- all forms are recognized by oligomer-specific MAb T4 and show enhanced binding of CD4i MAb 17b when sCD4 is bound -- the fused forms are less efficiently recognized than the cleaved forms by polyclonal neutralizing sera from HIV-infected patients -- the V3 loop is more exposed on the fused form. Stamatatos2000 (vaccine antigen design)
17b: sCD4 can activate fusion between effector cells expressing Env and target cells expressing coreceptor (CCR5 or CXCR4) alone without CD4 -- CD4i MAbs 17b and 48d have little effect on a standard cell fusion assay but potently block sCD4 activated fusion -- 17b was broadly cross-reactive inhibiting sCD4 activated fusion with Env from clades A, B, C, D, E, F, and F/B. Salzwedel2000 (subtype comparisons)
17b: Six mutations in MN change the virus from a high-infectivity neutralization resistant phenotype to low-infectivity neutralization sensitive -- V3, CD4BS, and CD4i MAbs are 20-100 fold more efficient at neutralizing the sensitive form -- the mutation L544P reduced binding of all MAbs against gp120 by causing conformational changes. Park2000 (antibody binding site)
17b: SF162 is a neutralization-resistant HIV-1 isolate -- N-linked glycosylation modifications in the V2 loop of the SF162 gp120 revealed that these sites prevent neutralization by CD4BS MAbs (IgG1b12 and IgGCD4), and protect against neutralization by V3 MAbs (447-D and 391-95D) -- V2-region glycosylation site mutations did not alter neutralization resistance to V2 MAbs (G3.4 and G3.136) or CD4i MAbs (17b and 48d) -- V2 glycosylation site modification allows infection of macrophages, probably due to glycosylated forms requiring fewer CCR5 molecules for viral entry. Ly2000 (variant cross-reactivity)
17b: To determine the antigenicity of virus killed by thermal and chemical inactivation, retention of conformation-dependent neutralization epitopes was examined, and exposure of CD4BS epitopes was found to be enhanced (MAbs IgG1b12, 205-46-9, and 205-43-1) -- binding to 2G12 and 447-52D epitopes was essentially unaltered -- the 17b CD4i epitope was also exposed. Grovit-Ferbas2000 (vaccine antigen design)
17b: The MAbs with the broadest neutralizing activity, IgG1b12, 2G12 and 2F5, all have high affinity for the native trimer, indicating that they were raised in an immune response to the oligomer on the virion surface rather than dissociated subunits -- a disulfide linked gp120-gp41 (SOS gp140) was created to mimic the native conformation of Env and explore its potential as an immunogen -- SOS gp140 is recognized by NAbs IgG1b12, 2G12, and CD4-IgG2, and also by anti-V3 MAbs 19b and 83.1 -- SOSgp140 is not recognized by C4 region MAbs that neutralize only TCLA strains, G3-42 and G3-519 -- nor did it bind C11, 23A, and M90, MAbs that bind to gp120 C1 and C5, where it interacts with gp41 -- MAbs that bind CD4 inducible epitopes, 17b and A32 were very strongly induced by CD4 in SOS gp140 -- anti-gp41 MAbs that bind in the region that interacts with gp120, 7B2, 2.2B, T4, T15G1 and 4D4, did not bind to SOSgp140, in contrast to 2F5, which binds to the only gp41 epitope that is well exposed in native gp120-gp41 complexes. Binley2000 (vaccine antigen design)
17b: A CD4-independent viral variant of IIIB, IIIBx, was generated on CXCR4-expressing cells -- IIIBx exhibited greater exposure of the 17b and 48d epitopes and enhanced neutralization by CD4i MAbs and by polyclonal human sera -- the 17b epitope has significant overlap with the CCR5 coreceptor binding site. Hoffman1999 (antibody binding site, variant cross-reactivity)
17b: Deleting the V2 loop of neutralization-resistant HIV-1 isolate SF162 does not abrogate its replication in PBMC or macrophages, but it enhances its neutralization sensitivity to sera from patients with B clade infection up to 170-fold, and also enhances sensitivity to sera from clades A through F -- deletion of V2 but not V1 enabled neutralization by CD4i MAbs 17b and 48d. Stamatatos1998 (antibody binding site, vaccine antigen design)
17b: A panel of MAbs was shown to bind with similar or greater affinity and similar competition profiles to a deglycosylated or variable loop deleted core gp120 protein (Delta V1, V2, and V3), thus such a core protein produces a structure closely approximating full length folded monomer -- CD4i MAbs 17b and 48d bound better to the deleted protein than to wild type. Binley1998 (antibody binding site)
17b: The HIV-1 virus YU2 entry can be enhanced by MAbs binding to the CD4BS, V3 loop, and CD4i epitopes -- the activation for this enhanced entry state could be conferred on HxB2 by introducing the YU2 V3 loop, or the YU2 V3 and V1/V2 loops, and the presence of V1/V2 increased the enhancement -- a similar effect is observed by sub-neutralizing concentrations of sCD4 and the effect is dependent of CCR5 -- 17b enhances YU2 enhanced viral entry 10-fold, whereas HXBc2 was neutralized. Sullivan1998b
17b: sCD4 induces 17b binding in primary isolates and TCLA strains -- amino acids that reduce the efficiency of binding were determined and found also to compromise syncytia formation and viral entry -- V1V2 deletion or sCD4 binding can expose the 17b epitope for both HXBc2 and macrophage tropic YU2 -- neutralizing potency of 17b is probably weak due to poor exposure of the epitope -- 17b epitope exposure upon sCD4 binding can occur over a wide range of temperatures, consistent with the energy of CD4 binding being sufficient to drive the V1/V2 loop into a new conformation. Sullivan1998 (antibody binding site, variant cross-reactivity)
17b: Site directed mutagenesis of a WU2 protein with the V1-V2 loops deleted revealed key residues for 17b-gp120 interaction and interaction of gp120 and CCR5 -- mutations in residues that reduced 17b by 70% were R/D 419, I/R 420, Q/L 422, Y/S 435, I/S 423, K/D 121 and K/D 421-- 17b can neutralize HIV-1 strains that use different chemokine receptors, supporting a common region in gp120 in chemokine-receptor interaction. Rizzuto1998 (antibody binding site, variant cross-reactivity)
17b: Moore and Binley provide a commentary on the papers by Rizzuto1998, Wyatt1998 and Kwong1998 -- they point out 17b shares binding elements in gp120 with chemokine receptor molecules, and that CD4 needs to bind to gp120 first to make the 17b epitope accessible and it may be sterically blocked in the CD4 bound virus, thus making it a poor NAb for primary isolates Moore1998. Kwong1998,Moore1998,Rizzuto1998,Wyatt1998 (review, structure)
17b: Summary of the implications of the crystal structure of a gp120 core bound to CD4 and 17b, combined with what is known about mutations that reduce NAb binding to gp120 -- probable mechanism of neutralization is interference with chemokine receptor binding -- mutations in 88N, 117K, 121K, 256S, 257T, N262, Delta V3, E370, E381, F 382, R 419, I 420, K 421, Q 422, I 423, W 427, Y 435, P 438, M 475 of HXBc2 (IIIB) reduce binding -- the only variable residues in gp120 that contact 17b are 202T and 434M -- the contact points for 17b with the crystallized incomplete gp120 are mostly in the heavy chain of the Ab, and there is a gap between 17b's light chain and the partial gp120 which may be occupied by the V3 loop in a complete gp120 molecule -- the authors propose that the V2 and V3 loops may mask the CD4i Ab binding site, and that the V2 loop may be repositioned upon CD4 binding. Wyatt1998 (structure)
17b: 17b Fab was co-crystallized with a gp120 core and CD4, and its binding site can be directly visualized---17b binds to the "bridging sheet" of gp120, an antiparallel beta sheet region, contacting residues from the C4 region and the V1/V2 stem---the contact area is small for an Ab-antigen interactive surface, and dominated in the Ab by the heavy chain---the center of the binding region has hydrophobic interactions, and the periphery charge interactions, acidic on 17b and basic on gp120. Kwong1998 (structure)
17b: Neutralizes TCLA strains, but not primary isolates. Parren1997 (variant cross-reactivity)
17b: Binds to sgp120 efficiently, but not soluble gp120+gp41, suggesting its gp120 epitope is blocked by gp41 binding -- partial re-exposure if sCD4 was bound -- could not bind to HXBc2 gp120 if the 19 C-term amino acids were deleted in conjunction with amino acids 31-93 in C1, but binding was restored in the presence of sCD4. Wyatt1997 (antibody binding site)
17b: Virus with the V1-V2 loop deleted was viable and more susceptible to neutralization by CD4i MAb 17b, and anti-V3 MAbs 1121, 9284, and 110.4, but not to a CD4BS MAb, F105, or sCD4. Cao1997 (vaccine antigen design)
17b: 48d binds to the IIIB protein and not IIIB V3 peptide, while binding to the Can0A V3 peptide, suggesting Can0A V3 is a conformer that mimics the 48d -- it does not bind to 17b, distinguishing the epitopes. Weinberg1997
17b: One of 14 human MAbs tested for ability to neutralize a chimeric SHIV-vpu+, which expressed HIV-1 IIIB env -- 17b has synergistic response in combination with anti-V3 MAb 694/98-D. Li1997
17b: Study shows neutralization is not predicted by MAb binding to JRFL monomeric gp120, but is associated with oligomeric Env binding -- 17b bound monomer, oligomer, and neutralized JRFL in the presence of sCD4, but if sCD4 was not present, 17b only bound monomer. Fouts1997
17b: Neutralizes JR-FL -- inhibits gp120 interaction with CCR-5 in a MIP-1beta-CCR-5 competition study. Trkola1996b
17b: MIP-1α binding to CCR-5 expressing cells can be inhibited by gp120-sCD4 --- binding of 17b blocks this inhibition. Wu1996
17b: Binding did not result in significant gp120 dissociation from virion, in contrast to 48d, although the gp41 epitope of MAb 50-69 was exposed. Poignard1996b (antibody interactions)
17b: Many MAbs inhibit binding (anti-C1, -C5, -C4, -CD4BS) -- anti-V3 MAb 5G11 enhances binding, as do C1-C4 discontinuous epitopes A32 and 2/11c -- enhances binding of some anti-V2 MAbs. Moore1996 (antibody interactions)
17b: Binds with higher affinity to monomer and oligomer, slow association rate, poor neutralization of lab strain -- this is in contrast to 48d, which has very different kinetics. Sattentau1995a (kinetics, binding affinity)
17b: Studies using a V1/V2 deletion mutant demonstrated that enhanced binding of 17b in the presence sCD4 involves the V1/V2 loops, with more significant involvement of V2 -- similar effect observed for 48d and A32. Wyatt1995 (antibody binding site, vaccine antigen design)
17b: A mutation in gp41, 582 A/T, confers resistance to neutralization (also confers resistance to MAbs F105, 48d, 21h and 15e). Thali1994 (variant cross-reactivity)
17b: Binding of 48d is much more influenced by sequence variation among molecular clones of LAI than is binding of 17b. Moore1993d (variant cross-reactivity)
17b: Epitope is better exposed upon CD4 binding to gp120 -- competes with 15e and 21h, anti-CD4 binding site MAbs -- 113 D/R, 252 R/W, 257 T/A or G, 370 E/D, 382 F/L, 420 I/R, 433A/L, 438 P/R and 475 M/S confer decreased sensitivity to neutralization. Thali1993 (antibody binding site, antibody interactions)
17b database comments: 48d and 17b have similar epitopes, and the pair are unique among human and rodent MAbs. Thali1993 mentions that 17b and 48d were derived from different patients, and cites the original generation of these antibodies to Robinson and Ho, unpublished data. 17b is a CHAVI reagent (http://chavi.org/); Species: human; Category: CD4i MAbs; Contact person: James Robinson (antibody binding site, antibody generation)

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Davis2009 Katie L. Davis, Frederic Bibollet-Ruche, Hui Li, Julie M. Decker, Olaf Kutsch, Lynn Morris, Aidy Salomon, Abraham Pinter, James A. Hoxie, Beatrice H. Hahn, Peter D. Kwong, and George M. Shaw. Human Immunodeficiency Virus Type 2 (HIV-2)/HIV-1 Envelope Chimeras Detect High Titers of Broadly Reactive HIV-1 V3-Specific Antibodies in Human Plasma. J. Virol., 83(3):1240-1259, Feb 2009. PubMed ID: 19019969. Show all entries for this paper.

Depetris2012 Rafael S Depetris, Jean-Philippe Julien, Reza Khayat, Jeong Hyun Lee, Robert Pejchal, Umesh Katpally, Nicolette Cocco, Milind Kachare, Evan Massi, Kathryn B. David, Albert Cupo, Andre J. Marozsan, William C. Olson, Andrew B. Ward, Ian A. Wilson, Rogier W. Sanders, and John P Moore. Partial Enzymatic Deglycosylation Preserves the Structure of Cleaved Recombinant HIV-1 Envelope Glycoprotein Trimers. J. Biol. Chem., 287(29):24239-24254, 13 Jul 2012. PubMed ID: 22645128. Show all entries for this paper.

Derby2006 Nina R. Derby, Zane Kraft, Elaine Kan, Emma T. Crooks, Susan W. Barnett, Indresh K. Srivastava, James M. Binley, and Leonidas Stamatatos. Antibody Responses Elicited in Macaques Immunized with Human Immunodeficiency Virus Type 1 (HIV-1) SF162-Derived gp140 Envelope Immunogens: Comparison with Those Elicited during Homologous Simian/Human Immunodeficiency Virus SHIVSF162P4 and Heterologous HIV-1 Infection. J. Virol., 80(17):8745-8762, Sep 2006. PubMed ID: 16912322. Show all entries for this paper.

Dervillez2010 Xavier Dervillez, Volker Klaukien, Ralf Dürr, Joachim Koch, Alexandra Kreutz, Thomas Haarmann, Michaela Stoll, Donghan Lee, Teresa Carlomagno, Barbara Schnierle, Kalle Möbius, Christoph Königs, Christian Griesinger, and Ursula Dietrich. Peptide Ligands Selected with CD4-Induced Epitopes on Native Dualtropic HIV-1 Envelope Proteins Mimic Extracellular Coreceptor Domains and Bind to HIV-1 gp120 Independently of Coreceptor Usage. J. Virol., 84(19):10131-10138, Oct 2010. PubMed ID: 20660187. Show all entries for this paper.

deTaeye2018 Steven W. de Taeye, Alba Torrents de la Peña, Andrea Vecchione, Enzo Scutigliani, Kwinten Sliepen, Judith A. Burger, Patricia van der Woude, Anna Schorcht, Edith E. Schermer, Marit J. van Gils, Celia C. LaBranche, David C. Montefiori, Ian A. Wilson, John P. Moore, Andrew B. Ward, and Rogier W. Sanders. Stabilization of the gp120 V3 Loop through Hydrophobic Interactions Reduces the Immunodominant V3-Directed Non-Neutralizing Response to HIV-1 Envelope Trimers. J. Biol. Chem., 293(5):1688-1701, 2 Feb 2018. PubMed ID: 29222332. Show all entries for this paper.

DeVico2007 Anthony DeVico, Timothy Fouts, George K. Lewis, Robert C. Gallo, Karla Godfrey, Manhattan Charurat, Ilia Harris, Lindsey Galmin, and Ranajit Pal. Antibodies to CD4-Induced Sites in HIV gp120 Correlate with the Control of SHIV Challenge in Macaques Vaccinated with Subunit Immunogens. Proc. Natl. Acad. Sci. U.S.A., 104(44):17477-17482, 30 Oct 2007. PubMed ID: 17956985. Show all entries for this paper.

Dey2003 Barna Dey, Christie S. Del Castillo, and Edward A. Berger. Neutralization of Human Immunodeficiency Virus Type 1 by sCD4-17b, a Single-Chain Chimeric Protein, Based on Sequential Interaction of gp120 with CD4 and Coreceptor. J. Virol., 77(5):2859-2865, Mar 2003. PubMed ID: 12584309. Show all entries for this paper.

Dey2007 Antu K. Dey, Kathryn B. David, Per J. Klasse, and John P. Moore. Specific Amino Acids in the N-Terminus of the gp41 Ectodomain Contribute to the Stabilization of a Soluble, Cleaved gp140 Envelope Glycoprotein from Human Immunodeficiency Virus Type 1. Virology, 360(1):199-208, 30 Mar 2007. PubMed ID: 17092531. Show all entries for this paper.

Dey2007a Barna Dey, Marie Pancera, Krisha Svehla, Yuuei Shu, Shi-Hua Xiang, Jeffrey Vainshtein, Yuxing Li, Joseph Sodroski, Peter D Kwong, John R Mascola, and Richard Wyatt. Characterization of Human Immunodeficiency Virus Type 1 Monomeric and Trimeric gp120 Glycoproteins Stabilized in the CD4-Bound State: Antigenicity, Biophysics, and Immunogenicity. J Virol, 81(11):5579-5593, Jun 2007. PubMed ID: 17360741. Show all entries for this paper.

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Dey2009 Barna Dey, Krisha Svehla, Ling Xu, Dianne Wycuff, Tongqing Zhou, Gerald Voss, Adhuna Phogat, Bimal K. Chakrabarti, Yuxing Li, George Shaw, Peter D. Kwong, Gary J. Nabel, John R. Mascola, and Richard T. Wyatt. Structure-Based Stabilization of HIV-1 gp120 Enhances Humoral Immune Responses to the Induced Co-Receptor Binding Site. PLoS Pathog, 5(5):e1000445, May 2009. PubMed ID: 19478876. Show all entries for this paper.

Ding2015 Shilei Ding, Maxime Veillette, Mathieu Coutu, Jérémie Prévost, Louise Scharf, Pamela J. Bjorkman, Guido Ferrari, James E. Robinson, Christina Stürzel, Beatrice H. Hahn, Daniel Sauter, Frank Kirchhoff, George K. Lewis, Marzena Pazgier, and Andrés Finzi. A Highly Conserved Residue of the HIV-1 gp120 Inner Domain Is Important for Antibody-Dependent Cellular Cytotoxicity Responses Mediated by Anti-cluster A Antibodies. J. Virol., 90(4):2127-2134, Feb 2016. PubMed ID: 26637462. Show all entries for this paper.

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Dorfman2006 Tatyana Dorfman, Michael J. Moore, Alexander C. Guth, Hyeryun Choe, and Michael Farzan. A Tyrosine-Sulfated Peptide Derived from the Heavy-Chain CDR3 Region of an HIV-1-Neutralizing Antibody Binds gp120 and Inhibits HIV-1 Infection. J. Biol. Chem., 281(39):28529-28535, 29 Sep 2006. PubMed ID: 16849323. Show all entries for this paper.

Douagi2010 Iyadh Douagi, Mattias N. E. Forsell, Christopher Sundling, Sijy O'Dell, Yu Feng, Pia Dosenovic, Yuxing Li, Robert Seder, Karin Loré, John R. Mascola, Richard T. Wyatt, and Gunilla B. Karlsson Hedestam. Influence of Novel CD4 Binding-Defective HIV-1 Envelope Glycoprotein Immunogens on Neutralizing Antibody and T-Cell Responses in Nonhuman Primates. J. Virol., 84(4):1683-1695, Feb 2010. PubMed ID: 19955308. Show all entries for this paper.

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EdwardsBH2002 Bradley H. Edwards, Anju Bansal, Steffanie Sabbaj, Janna Bakari, Mark J. Mulligan, and Paul A. Goepfert. Magnitude of Functional CD8+ T-Cell Responses to the Gag Protein of Human Immunodeficiency Virus Type 1 Correlates Inversely with Viral Load in Plasma. J. Virol., 76(5):2298-2305, Mar 2002. PubMed ID: 11836408. Show all entries for this paper.

Enshell-Seijffers2003 David Enshell-Seijffers, Dmitri Denisov, Bella Groisman, Larisa Smelyanski, Ronit Meyuhas, Gideon Gross, Galina Denisova, and Jonathan M. Gershoni. The Mapping and Reconstitution of a Conformational Discontinuous B-Cell Epitope of HIV-1. J. Mol. Biol., 334(1):87-101, 14 Nov 2003. PubMed ID: 14596802. Show all entries for this paper.

Feng2012 Yu Feng, Krisha McKee, Karen Tran, Sijy O'Dell, Stephen D. Schmidt, Adhuna Phogat, Mattias N. Forsell, Gunilla B. Karlsson Hedestam, John R. Mascola, and Richard T. Wyatt. Biochemically Defined HIV-1 Envelope Glycoprotein Variant Immunogens Display Differential Binding and Neutralizing Specificities to the CD4-Binding Site. J. Biol. Chem., 287(8):5673-5686, 17 Feb 2012. PubMed ID: 22167180. Show all entries for this paper.

Ferrari2011a Guido Ferrari, Justin Pollara, Daniel Kozink, Tiara Harms, Mark Drinker, Stephanie Freel, M. Anthony Moody, S. Munir Alam, Georgia D. Tomaras, Christina Ochsenbauer, John C. Kappes, George M. Shaw, James A. Hoxie, James E. Robinson, and Barton F. Haynes. An HIV-1 gp120 Envelope Human Monoclonal Antibody That Recognizes a C1 Conformational Epitope Mediates Potent Antibody-Dependent Cellular Cytotoxicity (ADCC) Activity and Defines a Common ADCC Epitope in Human HIV-1 Serum. J. Virol., 85(14):7029-7036, Jul 2011. PubMed ID: 21543485. Show all entries for this paper.

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Finzi2010 Andrés Finzi, Beatriz Pacheco, Xin Zeng, Young Do Kwon, Peter D. Kwong, and Joseph Sodroski. Conformational Characterization of Aberrant Disulfide-Linked HIV-1 gp120 Dimers Secreted from Overexpressing Cells. J Virol Methods, 168(1-2):155-161, Sep 2010. PubMed ID: 20471426. Show all entries for this paper.

Forsell2008 Mattias N. E. Forsell, Barna Dey, Andreas Mörner, Krisha Svehla, Sijy O'dell, Carl-Magnus Högerkorp, Gerald Voss, Rigmor Thorstensson, George M. Shaw, John R. Mascola, Gunilla B. Karlsson Hedestam, and Richard T. Wyatt. B Cell Recognition of the Conserved HIV-1 Co-Receptor Binding Site Is Altered by Endogenous Primate CD4. PLoS Pathog., 4(10):e1000171, 2008. PubMed ID: 18833294. Show all entries for this paper.

Forsman2008 Anna Forsman, Els Beirnaert, Marlén M. I. Aasa-Chapman, Bart Hoorelbeke, Karolin Hijazi, Willie Koh, Vanessa Tack, Agnieszka Szynol, Charles Kelly, Áine McKnight, Theo Verrips, Hans de Haard, and Robin A Weiss. Llama Antibody Fragments with Cross-Subtype Human Immunodeficiency Virus Type 1 (HIV-1)-Neutralizing Properties and High Affinity for HIV-1 gp120. J. Virol., 82(24):12069-12081, Dec 2008. PubMed ID: 18842738. Show all entries for this paper.

Fouda2013 Genevieve G. Fouda, Tatenda Mahlokozera, Jesus F. Salazar-Gonzalez, Maria G. Salazar, Gerald Learn, Surender B. Kumar, S. Moses Dennison, Elizabeth Russell, Katherine Rizzolo, Frederick Jaeger, Fangping Cai, Nathan A. Vandergrift, Feng Gao, Beatrice Hahn, George M. Shaw, Christina Ochsenbauer, Ronald Swanstrom, Steve Meshnick, Victor Mwapasa, Linda Kalilani, Susan Fiscus, David Montefiori, Barton Haynes, Jesse Kwiek, S. Munir Alam, and Sallie R. Permar. Postnatally-Transmitted HIV-1 Envelope Variants Have Similar Neutralization-Sensitivity and Function to That of Nontransmitted Breast Milk Variants. Retrovirology, 10:3, 2013. PubMed ID: 23305422. Show all entries for this paper.

Fouts1997 T. R. Fouts, J. M. Binley, A. Trkola, J. E. Robinson, and J. P. Moore. Neutralization of the Human Immunodeficiency Virus Type 1 Primary Isolate JR-FL by Human Monoclonal Antibodies Correlates with Antibody Binding to the Oligomeric Form of the Envelope Glycoprotein Complex. J. Virol., 71:2779-2785, 1997. To test whether antibody neutralization of HIV-1 primary isolates is correlated with the affinities for the oligomeric envelope glycoproteins, JRFL was used as a model primary virus and a panel of 13 human MAbs were evaluated for: half-maximal binding to rec monomeric JRFL gp120; half-maximal binding to oligomeric - JRFL Env expressed on the surface of transfected 293 cells; and neutralization of JRFL in a PBMC-based neutralization assay. Antibody affinity for oligomeric JRFL Env but not monomeric JRFL gp120 correlated with JRFL neutralization. PubMed ID: 9060632. Show all entries for this paper.

Frey2008 Gary Frey, Hanqin Peng, Sophia Rits-Volloch, Marco Morelli, Yifan Cheng, and Bing Chen. A Fusion-Intermediate State of HIV-1 gp41 Targeted by Broadly Neutralizing Antibodies. Proc. Natl. Acad. Sci. U.S.A., 105(10):3739-3744, 11 Mar 2008. PubMed ID: 18322015. Show all entries for this paper.

Fu2018 Qingshan Fu, Md Munan Shaik, Yongfei Cai, Fadi Ghantous, Alessandro Piai, Hanqin Peng, Sophia Rits-Volloch, Zhijun Liu, Stephen C. Harrison, Michael S. Seaman, Bing Chen, and James J. Chou. Structure of the Membrane Proximal External Region of HIV-1 Envelope Glycoprotein. Proc. Natl. Acad. Sci. U.S.A., 115(38):E8892-E8899, 18 Sep 2018. PubMed ID: 30185554. Show all entries for this paper.

Gach2014 Johannes S. Gach, Chad J. Achenbach, Veronika Chromikova, Baiba Berzins, Nina Lambert, Gary Landucci, Donald N. Forthal, Christine Katlama, Barbara H. Jung, and Robert L. Murphy. HIV-1 Specific Antibody Titers and Neutralization among Chronically Infected Patients on Long-Term Suppressive Antiretroviral Therapy (ART): A Cross-Sectional Study. PLoS One, 9(1):e85371, 2014. PubMed ID: 24454852. Show all entries for this paper.

Gao2005a Feng Gao, Eric A. Weaver, Zhongjing Lu, Yingying Li, Hua-Xin Liao, Benjiang Ma, S Munir Alam, Richard M. Scearce, Laura L. Sutherland, Jae-Sung Yu, Julie M. Decker, George M. Shaw, David C. Montefiori, Bette T. Korber, Beatrice H. Hahn, and Barton F. Haynes. Antigenicity and Immunogenicity of a Synthetic Human Immunodeficiency Virus Type 1 Group M Consensus Envelope Glycoprotein. J. Virol., 79(2):1154-1163, Jan 2005. PubMed ID: 15613343. Show all entries for this paper.

Gao2007 Feng Gao, Hua-Xin Liao, Beatrice H. Hahn, Norman L. Letvin, Bette T. Korber, and Barton F. Haynes. Centralized HIV-1 Envelope Immunogens and Neutralizing Antibodies. Curr. HIV Res., 5(6):572-577, Nov 2007. PubMed ID: 18045113. Show all entries for this paper.

Gao2009 Feng Gao, Richard M. Scearce, S. Munir Alam, Bhavna Hora, Shimao Xia, Julie E. Hohm, Robert J. Parks, Damon F. Ogburn, Georgia D. Tomaras, Emily Park, Woodrow E. Lomas, Vernon C. Maino, Susan A. Fiscus, Myron S. Cohen, M. Anthony Moody, Beatrice H. Hahn, Bette T. Korber, Hua-Xin Liao, and Barton F. Haynes. Cross-reactive Monoclonal Antibodies to Multiple HIV-1 Subtype and SIVcpz Envelope Glycoproteins. Virology, 394(1):91-98, 10 Nov 2009. PubMed ID: 19744690. Show all entries for this paper.

GoldingH2002 Hana Golding, Marina Zaitseva, Eve de Rosny, Lisa R. King, Jody Manischewitz, Igor Sidorov, Miroslaw K. Gorny, Susan Zolla-Pazner, Dimiter S. Dimitrov, and Carol D. Weiss. Dissection of Human Immunodeficiency Virus Type 1 Entry with Neutralizing Antibodies to gp41 Fusion Intermediates. J. Virol., 76(13):6780-6790, Jul 2002. PubMed ID: 12050391. Show all entries for this paper.

Gopi2008 Hosahudya Gopi, M. Umashankara, Vanessa Pirrone, Judith LaLonde, Navid Madani, Ferit Tuzer, Sabine Baxter, Isaac Zentner, Simon Cocklin, Navneet Jawanda, Shendra R. Miller, Arne Schön, Jeffrey C. Klein, Ernesto Freire, Fred C. Krebs, Amos B. Smith, Joseph Sodroski, and Irwin Chaiken. Structural Determinants for Affinity Enhancement of a Dual Antagonist Peptide Entry Inhibitor of Human Immunodeficiency Virus Type-1. J. Med. Chem., 51(9):2638-2647, 8 May 2008. PubMed ID: 18402432. Show all entries for this paper.

Gorny2003 Miroslaw K. Gorny and Susan Zolla-Pazner. Human Monoclonal Antibodies that Neutralize HIV-1. In Bette T. M. Korber and et. al., editors, HIV Immunology and HIV/SIV Vaccine Databases 2003. pages 37--51. Los Alamos National Laboratory, Theoretical Biology \& Biophysics, Los Alamos, N.M., 2004. URL: http://www.hiv.lanl.gov/content/immunology/pdf/2003/zolla-pazner_article.pdf. LA-UR 04-8162. Show all entries for this paper.

Gorny2009 Miroslaw K. Gorny, Xiao-Hong Wang, Constance Williams, Barbara Volsky, Kathy Revesz, Bradley Witover, Sherri Burda, Mateusz Urbanski, Phillipe Nyambi, Chavdar Krachmarov, Abraham Pinter, Susan Zolla-Pazner, and Arthur Nadas. Preferential Use of the VH5-51 Gene Segment by the Human Immune Response to Code for Antibodies against the V3 Domain of HIV-1. Mol. Immunol., 46(5):917-926, Feb 2009. PubMed ID: 18952295. Show all entries for this paper.

Grovit-Ferbas2000 K. Grovit-Ferbas, J. F. Hsu, J. Ferbas, V. Gudeman, and I. S. Chen. Enhanced binding of antibodies to neutralization epitopes following thermal and chemical inactivation of human immunodeficiency virus type 1. J. Virol., 74(13):5802-9, Jul 2000. URL: http://jvi.asm.org/cgi/content/full/74/13/5802. PubMed ID: 10846059. Show all entries for this paper.

Grundner2002 Christoph Grundner, Tajib Mirzabekov, Joseph Sodroski, and Richard Wyatt. Solid-Phase Proteoliposomes Containing Human Immunodeficiency Virus Envelope Glycoproteins. J. Virol., 76(7):3511-3521, Apr 2002. PubMed ID: 11884575. Show all entries for this paper.

Haim2011 Hillel Haim, Bettina Strack, Aemro Kassa, Navid Madani, Liping Wang, Joel R. Courter, Amy Princiotto, Kathleen McGee, Beatriz Pacheco, Michael S. Seaman, Amos B. Smith, 3rd., and Joseph Sodroski. Contribution of Intrinsic Reactivity of the HIV-1 Envelope Glycoproteins to CD4-Independent Infection and Global Inhibitor Sensitivity. PLoS Pathog., 7(6):e1002101, Jun 2011. PubMed ID: 21731494. Show all entries for this paper.

Haynes2005 Barton F. Haynes, Judith Fleming, E. William St. Clair, Herman Katinger, Gabriela Stiegler, Renate Kunert, James Robinson, Richard M. Scearce, Kelly Plonk, Herman F. Staats, Thomas L. Ortel, Hua-Xin Liao, and S. Munir Alam. Cardiolipin Polyspecific Autoreactivity in Two Broadly Neutralizing HIV-1 Antibodies. Science, 308(5730):1906-1908, 24 Jun 2005. Comment in Science 2005 Jun 24;308(5730):1878-9. PubMed ID: 15860590. Show all entries for this paper.

Haynes2010 Barton F. Haynes, Nathan I. Nicely, and S. Munir Alam. HIV-1 Autoreactive Antibodies: Are They Good or Bad for HIV-1 Prevention? Nat. Struct. Mol. Biol., 17(5):543-545, May 2010. PubMed ID: 20442740. Show all entries for this paper.

He2003 Yuxian He, Paul D'Agostino, and Abraham Pinter. Analysis of the Immunogenic Properties of a Single-Chain Polypeptide Analogue of the HIV-1 gp120-CD4 Complex in Transgenic Mice That Produce Human Immunoglobulins. Vaccine, 21(27-30):4421-4429, 1 Oct 2003. PubMed ID: 14505925. Show all entries for this paper.

Hicar2010 Mark D. Hicar, Xuemin Chen, Bryan Briney, Jason Hammonds, Jaang-Jiun Wang, Spyros Kalams, Paul W. Spearman, and James E. Crowe, Jr. Pseudovirion Particles Bearing Native HIV Envelope Trimers Facilitate a Novel Method for Generating Human Neutralizing Monoclonal Antibodies Against HIV. J. Acquir. Immune Defic. Syndr., 54(3):223-235, Jul 2010. PubMed ID: 20531016. Show all entries for this paper.

Hoffman1999 T. L. Hoffman, C. C. LaBranche, W. Zhang, G. Canziani, J. Robinson, I. Chaiken, J. A. Hoxie, and R. W. Doms. Stable exposure of the coreceptor-binding site in a CD4-independent HIV-1 envelope protein. Proc. Natl. Acad. Sci. U.S.A., 96(11):6359--64, 25 May 1999. URL: http://www.pnas.org/cgi/content/full/96/11/6359. PubMed ID: 10339592. Show all entries for this paper.

Holl2006 Vincent Holl, Maryse Peressin, Thomas Decoville, Sylvie Schmidt, Susan Zolla-Pazner, Anne-Marie Aubertin, and Christiane Moog. Nonneutralizing Antibodies Are Able To Inhibit Human Immunodeficiency Virus Type 1 Replication in Macrophages and Immature Dendritic Cells. J. Virol., 80(12):6177-6181, Jun 2006. PubMed ID: 16731957. Show all entries for this paper.

Hu2007 Qinxue Hu, Naheed Mahmood, and Robin J. Shattock. High-Mannose-Specific Deglycosylation of HIV-1 gp120 Induced by Resistance to Cyanovirin-N and the Impact on Antibody Neutralization. Virology, 368(1):145-154, 10 Nov 2007. PubMed ID: 17658575. Show all entries for this paper.

Huang2005 Chih-chin Huang, Min Tang, Mei-Yun Zhang, Shahzad Majeed, Elizabeth Montabana, Robyn L. Stanfield, Dimiter S. Dimitrov, Bette Korber, Joseph Sodroski, Ian A. Wilson, Richard Wyatt, and Peter D. Kwong. Structure of a V3-Containing HIV-1 gp120 Core. Science, 310(5750):1025-1028, 11 Nov 2005. PubMed ID: 16284180. Show all entries for this paper.

Huang2007 Li Huang, Weihong Lai, Phong Ho, and Chin Ho Chen. Induction of a Nonproductive Conformational Change in gp120 by a Small Molecule HIV Type 1 Entry Inhibitor. AIDS Res. Hum. Retroviruses, 23(1):28-32, Jan 2007. PubMed ID: 17263629. Show all entries for this paper.

Huang2012 Xin Huang, Wei Jin, Kai Hu, Sukun Luo, Tao Du, George E. Griffin, Robin J. Shattock, and Qinxue Hu. Highly Conserved HIV-1 gp120 Glycans Proximal to CD4-Binding Region Affect Viral Infectivity and Neutralizing Antibody Induction. Virology, 423(1):97-106, 5 Feb 2012. PubMed ID: 22192629. Show all entries for this paper.

Johnson2017 Jacklyn Johnson, Yinjie Zhai, Hamid Salimi, Nicole Espy, Noah Eichelberger, Orlando DeLeon, Yunxia O'Malley, Joel Courter, Amos B. Smith, III, Navid Madani, Joseph Sodroski, and Hillel Haim. Induction of a Tier-1-Like Phenotype in Diverse Tier-2 Isolates by Agents That Guide HIV-1 Env to Perturbation-Sensitive, Nonnative States. J. Virol., 91(15), 1 Aug 2017. PubMed ID: 28490588. Show all entries for this paper.

Joubert2010 Marisa K. Joubert, Nichole Kinsley, Alexio Capovilla, B. Trevor Sewell, Mohamed A. Jaffer, and Makobetsa Khati. A Modeled Structure of an Aptamer-gp120 Complex Provides Insight into the Mechanism of HIV-1 Neutralization. Biochemistry, 49(28):5880-5890, 20 Jul 2010. PubMed ID: 20527993. Show all entries for this paper.

Joyner2011 Amanda S. Joyner, Jordan R. Willis, James E.. Crowe, Jr., and Christopher Aiken. Maturation-Induced Cloaking of Neutralization Epitopes on HIV-1 Particles. PLoS Pathog., 7(9):e1002234, Sep 2011. PubMed ID: 21931551. Show all entries for this paper.

Kalia2005 Vandana Kalia, Surojit Sarkar, Phalguni Gupta, and Ronald C. Montelaro. Antibody Neutralization Escape Mediated by Point Mutations in the Intracytoplasmic Tail of Human Immunodeficiency Virus Type 1 gp41. J. Virol., 79(4):2097-2107, Feb 2005. PubMed ID: 15681412. Show all entries for this paper.

Kang2005 Sang-Moo Kang, Fu Shi Quan, Chunzi Huang, Lizheng Guo, Ling Ye, Chinglai Yang, and Richard W. Compans. Modified HIV Envelope Proteins with Enhanced Binding to Neutralizing Monoclonal Antibodies. Virology, 331(1):20-32, 5 Jan 2005. PubMed ID: 15582650. Show all entries for this paper.

Kang2009 Yun Kenneth Kang, Sofija Andjelic, James M. Binley, Emma T. Crooks, Michael Franti, Sai Prasad N. Iyer, Gerald P. Donovan, Antu K. Dey, Ping Zhu, Kenneth H. Roux, Robert J. Durso, Thomas F. Parsons, Paul J. Maddon, John P. Moore, and William C. Olson. Structural and Immunogenicity Studies of a Cleaved, Stabilized Envelope Trimer Derived from Subtype A HIV-1. Vaccine, 27(37):5120-5132, 13 Aug 2009. PubMed ID: 19567243. Show all entries for this paper.

Keele2008 Brandon F. Keele, Elena E. Giorgi, Jesus F. Salazar-Gonzalez, Julie M. Decker, Kimmy T. Pham, Maria G. Salazar, Chuanxi Sun, Truman Grayson, Shuyi Wang, Hui Li, Xiping Wei, Chunlai Jiang, Jennifer L. Kirchherr, Feng Gao, Jeffery A. Anderson, Li-Hua Ping, Ronald Swanstrom, Georgia D. Tomaras, William A. Blattner, Paul A. Goepfert, J. Michael Kilby, Michael S. Saag, Eric L. Delwart, Michael P. Busch, Myron S. Cohen, David C. Montefiori, Barton F. Haynes, Brian Gaschen, Gayathri S. Athreya, Ha Y. Lee, Natasha Wood, Cathal Seoighe, Alan S. Perelson, Tanmoy Bhattacharya, Bette T. Korber, Beatrice H. Hahn, and George M. Shaw. Identification and Characterization of Transmitted and Early Founder Virus Envelopes in Primary HIV-1 Infection. Proc. Natl. Acad. Sci. U.S.A., 105(21):7552-7557, 27 May 2008. PubMed ID: 18490657. Show all entries for this paper.

Klein2013 Florian Klein, Ron Diskin, Johannes F. Scheid, Christian Gaebler, Hugo Mouquet, Ivelin S. Georgiev, Marie Pancera, Tongqing Zhou, Reha-Baris Incesu, Brooks Zhongzheng Fu, Priyanthi N. P. Gnanapragasam, Thiago Y. Oliveira, Michael S. Seaman, Peter D. Kwong, Pamela J. Bjorkman, and Michel C. Nussenzweig. Somatic Mutations of the Immunoglobulin Framework Are Generally Required for Broad and Potent HIV-1 Neutralization. Cell, 153(1):126-138, 28 Mar 2013. PubMed ID: 23540694. Show all entries for this paper.

Koefoed2005 Klaus Koefoed, Lauge Farnaes, Meng Wang, Arne Svejgaard, Dennis R. Burton, and Henrik J. Ditzel. Molecular Characterization of the Circulating Anti-HIV-1 gp120-Specific B Cell Repertoire using Antibody Phage Display Libraries Generated from Pre-Selected HIV-1 gp120 Binding PBLs. J. Immunol. Methods, 297(1-2):187-201, Feb 2005. PubMed ID: 15777942. Show all entries for this paper.

Kolchinsky2001 P. Kolchinsky, E. Kiprilov, P. Bartley, R. Rubinstein, and J. Sodroski. Loss of a single N-linked glycan allows CD4-independent human immunodeficiency virus type 1 infection by altering the position of the gp120 V1/V2 variable loops. J. Virol., 75(7):3435--43, Apr 2001. URL: http://jvi.asm.org/cgi/content/full/75/7/3435. PubMed ID: 11238869. Show all entries for this paper.

Korber2009 Bette Korber and S. Gnanakaran. The Implications of Patterns in HIV Diversity for Neutralizing Antibody Induction and Susceptibility. Curr. Opin. HIV AIDS, 4(5):408-417, Sep 2009. PubMed ID: 20048705. Show all entries for this paper.

Korkut2012 Anil Korkut and Wayne A. Hendrickson. Structural Plasticity and Conformational Transitions of HIV Envelope Glycoprotein gp120. PLoS One, 7(12):e52170, 2012. PubMed ID: 23300605. Show all entries for this paper.

Kothe2007 Denise L. Kothe, Julie M Decker, Yingying Li, Zhiping Weng, Frederic Bibollet-Ruche, Kenneth P. Zammit, Maria G. Salazar, Yalu Chen, Jesus F. Salazar-Gonzalez, Zina Moldoveanu, Jiri Mestecky, Feng Gao, Barton F. Haynes, George M. Shaw, Mark Muldoon, Bette T. M. Korber, and Beatrice H. Hahn. Antigenicity and Immunogenicity of HIV-1 Consensus Subtype B Envelope Glycoproteins. Virology, 360(1):218-234, 30 Mar 2007. PubMed ID: 17097711. Show all entries for this paper.

Kramer2007 Victor G. Kramer, Nagadenahalli B. Siddappa, and Ruth M. Ruprecht. Passive Immunization as Tool to Identify Protective HIV-1 Env Epitopes. Curr. HIV Res., 5(6):642-55, Nov 2007. PubMed ID: 18045119. Show all entries for this paper.

Kwong1998 P. D. Kwong, R. Wyatt, J. Robinson, R. W. Sweet, J. Sodroski, and W. A. Hendrickson. Structure of an HIV gp120 Envelope Glycoprotein in Complex with the CD4 Receptor and a Neutralizing Human Antibody. Nature, 393:648-659, 1998. Comment in Nature 1998 Jun 18;393(6686):630-1. The X-ray crystal structure was solved at 2.5 A resolution of HIV-1 gp120 core complexed with human CD4 and the antigen-binding fragment of a neutralizing antibody that blocks chemokine-receptor binding. PubMed ID: 9641677. Show all entries for this paper.

Kwong2002 Peter D. Kwong, Michael L. Doyle, David J. Casper, Claudia Cicala, Stephanie A. Leavitt, Shahzad Majeed, Tavis D. Steenbeke, Miro Venturi, Irwin Chaiken, Michael Fung, Hermann Katinger, Paul W. I. H. Parren, James Robinson, Donald Van Ryk, Liping Wang, Dennis R. Burton, Ernesto Freire, Richard Wyatt, Joseph Sodroski, Wayne A. Hendrickson, and James Arthos. HIV-1 Evades Antibody-Mediated Neutralization through Conformational Masking of Receptor-Binding Sites. Nature, 420(6916):678-682, 12 Dec 2002. Comment in Nature. 2002 Dec 12;420(6916):623-4. PubMed ID: 12478295. Show all entries for this paper.

Laakso2007 Meg M. Laakso, Fang-Hua Lee, Beth Haggarty, Caroline Agrawal, Katrina M. Nolan, Mark Biscone, Josephine Romano, Andrea P. O. Jordan, George J. Leslie, Eric G. Meissner, Lishan Su, James A. Hoxie, and Robert W. Doms. V3 Loop Truncations in HIV-1 Envelope Impart Resistance to Coreceptor Inhibitors and Enhanced Sensitivity to Neutralizing Antibodies. PLoS Pathog., 3(8):e117, 24 Aug 2007. PubMed ID: 17722977. Show all entries for this paper.

Labrijn2003 Aran F. Labrijn, Pascal Poignard, Aarti Raja, Michael B. Zwick, Karla Delgado, Michael Franti, James Binley, Veronique Vivona, Christoph Grundner, Chih-Chin Huang, Miro Venturi, Christos J. Petropoulos, Terri Wrin, Dimiter S. Dimitrov, James Robinson, Peter D. Kwong, Richard T. Wyatt, Joseph Sodroski, and Dennis R. Burton. Access of Antibody Molecules to the Conserved Coreceptor Binding Site on Glycoprotein gp120 Is Sterically Restricted on Primary Human Immunodeficiency Virus Type 1. J. Virol., 77(19):10557-10565, Oct 2003. PubMed ID: 12970440. Show all entries for this paper.

Lagenaur2010 Laurel A. Lagenaur, Vadim A. Villarroel, Virgilio Bundoc, Barna Dey, and Edward A. Berger. sCD4-17b Bifunctional Protein: Extremely Broad and Potent Neutralization of HIV-1 Env Pseudotyped Viruses from Genetically Diverse Primary Isolates. Retrovirology, 7:11, 2010. PubMed ID: 20158904. Show all entries for this paper.

Lai2012 Rachel P. J. Lai, Michael S. Seaman, Paul Tonks, Frank Wegmann, David J. Seilly, Simon D. W. Frost, Celia C. LaBranche, David C. Montefiori, Antu K. Dey, Indresh K. Srivastava, Quentin Sattentau, Susan W. Barnett, and Jonathan L. Heeney. Mixed Adjuvant Formulations Reveal a New Combination That Elicit Antibody Response Comparable to Freund's Adjuvants. PLoS One, 7(4):e35083, 2012. PubMed ID: 22509385. Show all entries for this paper.

LaLonde2012 Judith M. LaLonde, Young Do Kwon, David M. Jones, Alexander W. Sun, Joel R. Courter, Takahiro Soeta, Toyoharu Kobayashi, Amy M. Princiotto, Xueling Wu, Arne Schön, Ernesto Freire, Peter D. Kwong, John R. Mascola, Joseph Sodroski, Navid Madani, and Amos B. Smith, 3rd. Structure-Based Design, Synthesis, and Characterization of Dual Hotspot Small-Molecule HIV-1 Entry Inhibitors. J. Med. Chem., 55(9):4382-4396, 10 May 2012. PubMed ID: 22497421. Show all entries for this paper.

Lam2006 Yee Lam, Nehal I. Abu-Lail, Munir S. Alam, and Stefan Zauscher. Using Microcantilever Deflection to Detect HIV-1 Envelope Glycoprotein gp120. Nanomedicine, 2(4):222-229, Dec 2006. PubMed ID: 17292147. Show all entries for this paper.

Li1997 A. Li, T. W. Baba, J. Sodroski, S. Zolla-Pazner, M. K. Gorny, J. Robinson, M. R. Posner, H. Katinger, C. F. Barbas III, D. R. Burton, T.-C. Chou, and R. M Ruprecht. Synergistic Neutralization of a Chimeric SIV/HIV Type 1 Virus with Combinations of Human Anti-HIV Type 1 Envelope Monoclonal Antibodies or Hyperimmune Globulins. AIDS Res. Hum. Retroviruses, 13:647-656, 1997. Multiple combinations of MAbs were tested for their ability to synergize neutralization of a SHIV construct containing HIV IIIB env. All of the MAb combinations tried were synergistic, suggesting such combinations may be useful for passive immunotherapy or immunoprophylaxis. Because SHIV can replicate in rhesus macaques, such approaches can potentially be studied in an it in vivo monkey model. PubMed ID: 9168233. Show all entries for this paper.

Li2009c Yuxing Li, Krisha Svehla, Mark K. Louder, Diane Wycuff, Sanjay Phogat, Min Tang, Stephen A. Migueles, Xueling Wu, Adhuna Phogat, George M. Shaw, Mark Connors, James Hoxie, John R. Mascola, and Richard Wyatt. Analysis of Neutralization Specificities in Polyclonal Sera Derived from Human Immunodeficiency Virus Type 1-Infected Individuals. J Virol, 83(2):1045-1059, Jan 2009. PubMed ID: 19004942. Show all entries for this paper.

Li2012 Yuxing Li, Sijy O'Dell, Richard Wilson, Xueling Wu, Stephen D. Schmidt, Carl-Magnus Hogerkorp, Mark K. Louder, Nancy S. Longo, Christian Poulsen, Javier Guenaga, Bimal K. Chakrabarti, Nicole Doria-Rose, Mario Roederer, Mark Connors, John R. Mascola, and Richard T. Wyatt. HIV-1 Neutralizing Antibodies Display Dual Recognition of the Primary and Coreceptor Binding Sites and Preferential Binding to Fully Cleaved Envelope Glycoproteins. J. Virol., 86(20):11231-11241, Oct 2012. PubMed ID: 22875963. Show all entries for this paper.

Liao2004 Hua-Xin Liao, S Munir Alam, John R. Mascola, James Robinson, Benjiang Ma, David C. Montefiori, Maria Rhein, Laura L. Sutherland, Richard Scearce, and Barton F. Haynes. Immunogenicity of Constrained Monoclonal Antibody A32-Human Immunodeficiency Virus (HIV) Env gp120 Complexes Compared to That of Recombinant HIV Type 1 gp120 Envelope Glycoproteins. J. Virol., 78(10):5270-5278, May 2004. PubMed ID: 15113908. Show all entries for this paper.

Liao2006 Hua-Xin Liao, Laura L. Sutherland, Shi-Mao Xia, Mary E. Brock, Richard M. Scearce, Stacie Vanleeuwen, S. Munir Alam, Mildred McAdams, Eric A. Weaver, Zenaido Camacho, Ben-Jiang Ma, Yingying Li, Julie M. Decker, Gary J. Nabel, David C. Montefiori, Beatrice H. Hahn, Bette T. Korber, Feng Gao, and Barton F. Haynes. A Group M Consensus Envelope Glycoprotein Induces Antibodies That Neutralize Subsets of Subtype B and C HIV-1 Primary Viruses. Virology, 353(2):268-282, 30 Sep 2006. PubMed ID: 17039602. Show all entries for this paper.

Liao2013a Hongyan Liao, Jun-tao Guo, Miles D. Lange, Run Fan, Michael Zemlin, Kaihong Su, Yongjun Guan, and Zhixin Zhang. Contribution of V(H) Replacement Products to the Generation of Anti-HIV Antibodies. Clin. Immunol., 146(1):46-55, Jan 2013. PubMed ID: 23220404. Show all entries for this paper.

Lin2007 George Lin and Peter L. Nara. Designing Immunogens to Elicit Broadly Neutralizing Antibodies to the HIV-1 Envelope Glycoprotein. Curr. HIV Res., 5(6):514-541, Nov 2007. PubMed ID: 18045109. Show all entries for this paper.

Ling2002 Hong Ling, Xiao-Yan Zhang, Osamu Usami, and Toshio Hattori. Activation of gp120 of Human Immunodeficiency Virus by Their V3 Loop-Derived Peptides. Biochem. Biophys. Res. Commun., 297(3):625-631, 27 Sep 2002. PubMed ID: 12270140. Show all entries for this paper.

Ling2004 Hong Ling, Peng Xiao, Osamu Usami, and Toshio Hattori. Thrombin Activates Envelope Glycoproteins of HIV Type 1 and Enhances Fusion. Microbes Infect., 6(5):414-420, Apr 2004. PubMed ID: 15109955. Show all entries for this paper.

Liu2008 Jun Liu, Alberto Bartesaghi, Mario J. Borgnia, Guillermo Sapiro, and Sriram Subramaniam. Molecular Architecture of Native HIV-1 gp120 Trimers. Nature, 455(7209):109-113, 4 Sep 2008. PubMed ID: 18668044. Show all entries for this paper.

Lusso2005 Paolo Lusso, Patricia L. Earl, Francesca Sironi, Fabio Santoro, Chiara Ripamonti, Gabriella Scarlatti, Renato Longhi, Edward A. Berger, and Samuele E. Burastero. Cryptic Nature of a Conserved, CD4-Inducible V3 Loop Neutralization Epitope in the Native Envelope Glycoprotein Oligomer of CCR5-Restricted, but not CXCR4-Using, Primary Human Immunodeficiency Virus Type 1 Strains. J. Virol., 79(11):6957-6968, Jun 2005. PubMed ID: 15890935. Show all entries for this paper.

Ly2000 A. Ly and L. Stamatatos. V2 Loop Glycosylation of the Human Immunodeficiency Virus Type 1 SF162 Envelope Facilitates Interaction of this Protein with CD4 and CCR5 Receptors and Protects the Virus from Neutralization by Anti-V3 Loop and Anti-CD4 Binding Site Antibodies. J. Virol., 74:6769-6776, 2000. PubMed ID: 10888615. Show all entries for this paper.

Lynch2010 Rebecca M. Lynch, Rong Rong, Bing Li, Tongye Shen, William Honnen, Joseph Mulenga, Susan Allen, Abraham Pinter, S. Gnanakaran, and Cynthia A. Derdeyn. Subtype-Specific Conservation of Isoleucine 309 in the envelope V3 Domain Is Linked to Immune Evasion in Subtype C HIV-1 Infection. Virology, 404(1):59-70, 15 Aug 2010. PubMed ID: 20494390. Show all entries for this paper.

Lynch2012 Rebecca M. Lynch, Lillian Tran, Mark K. Louder, Stephen D. Schmidt, Myron Cohen, CHAVI 001 Clinical Team Members, Rebecca DerSimonian, Zelda Euler, Elin S. Gray, Salim Abdool Karim, Jennifer Kirchherr, David C. Montefiori, Sengeziwe Sibeko, Kelly Soderberg, Georgia Tomaras, Zhi-Yong Yang, Gary J. Nabel, Hanneke Schuitemaker, Lynn Morris, Barton F. Haynes, and John R. Mascola. The Development of CD4 Binding Site Antibodies during HIV-1 Infection. J. Virol., 86(14):7588-7595, Jul 2012. PubMed ID: 22573869. Show all entries for this paper.

Ma2011 Ben-Jiang Ma, S. Munir Alam, Eden P. Go, Xiaozhi Lu, Heather Desaire, Georgia D. Tomaras, Cindy Bowman, Laura L. Sutherland, Richard M. Scearce, Sampa Santra, Norman L. Letvin, Thomas B. Kepler, Hua-Xin Liao, and Barton F. Haynes. Envelope Deglycosylation Enhances Antigenicity of HIV-1 gp41 Epitopes for Both Broad Neutralizing Antibodies and Their Unmutated Ancestor Antibodies. PLoS Pathog., 7(9):e1002200, Sep 2011. PubMed ID: 21909262. Show all entries for this paper.

Magnus2010 Carsten Magnus and Roland R. Regoes. Estimating the Stoichiometry of HIV Neutralization. PLoS Comput. Biol., 6(3):e1000713, Mar 2010. PubMed ID: 20333245. Show all entries for this paper.

Martin2008 Grégoire Martin, Yide Sun, Bernadette Heyd, Olivier Combes, Jeffrey B Ulmer, Anne Descours, Susan W Barnett, Indresh K Srivastava, and Loïc Martin. A Simple One-Step Method for the Preparation of HIV-1 Envelope Glycoprotein Immunogens Based on a CD4 Mimic Peptide. Virology, 381(2):241-250, 25 Nov 2008. PubMed ID: 18835005. Show all entries for this paper.

Martin2011 Grégoire Martin, Brian Burke, Robert Thaï, Antu K. Dey, Olivier Combes, Bernadette Heyd, Anthony R. Geonnotti, David C. Montefiori, Elaine Kan, Ying Lian, Yide Sun, Toufik Abache, Jeffrey B. Ulmer, Hocine Madaoui, Raphaël Guérois, Susan W. Barnett, Indresh K. Srivastava, Pascal Kessler, and Loïc Martin. Stabilization of HIV-1 Envelope in the CD4-Bound Conformation through Specific Cross-Linking of a CD4 Mimetic. J. Biol. Chem., 286(24):21706-21716, 17 Jun 2011. PubMed ID: 21487012. Show all entries for this paper.

Martin-Garcia2005 Julio Martín-García, Simon Cocklin, Irwin M. Chaiken, and Francisco González-Scarano. Interaction with CD4 and Antibodies to CD4-Induced Epitopes of the Envelope gp120 from a Microglial Cell-Adapted Human Immunodeficiency Virus Type 1 Isolate. J. Virol., 79(11):6703-6713, Jun 2005. PubMed ID: 15890908. Show all entries for this paper.

Mascola2010 John R. Mascola and David C. Montefiori. The Role of Antibodies in HIV Vaccines. Annu. Rev. Immunol., 28:413-444, Mar 2010. PubMed ID: 20192810. Show all entries for this paper.

McCaffrey2004 Ruth A McCaffrey, Cheryl Saunders, Mike Hensel, and Leonidas Stamatatos. N-Linked Glycosylation of the V3 Loop and the Immunologically Silent Face of gp120 Protects Human Immunodeficiency Virus Type 1 SF162 from Neutralization by Anti-gp120 and Anti-gp41 Antibodies. J. Virol., 78(7):3279-3295, Apr 2004. PubMed ID: 15016849. Show all entries for this paper.

McCann2005 C. M. Mc Cann, R. J. Song, and R. M. Ruprecht. Antibodies: Can They Protect Against HIV Infection? Curr. Drug Targets Infect. Disord., 5(2):95-111, Jun 2005. PubMed ID: 15975016. Show all entries for this paper.

McFadden2007 Karyn McFadden, Simon Cocklin, Hosahudya Gopi, Sabine Baxter, Sandya Ajith, Naheed Mahmood, Robin Shattock, and Irwin Chaiken. A Recombinant Allosteric Lectin Antagonist of HIV-1 Envelope gp120 Interactions. Proteins, 67(3):617-629, 15 May 2007. PubMed ID: 17348010. Show all entries for this paper.

McKnight2007 Aine McKnight and Marlen M. I. Aasa-Chapman. Clade Specific Neutralising Vaccines for HIV: An Appropriate Target? Curr. HIV Res., 5(6):554-560, Nov 2007. PubMed ID: 18045111. Show all entries for this paper.

Melchers2012 Mark Melchers, Ilja Bontjer, Tommy Tong, Nancy P. Y. Chung, Per Johan Klasse, Dirk Eggink, David C. Montefiori, Maurizio Gentile, Andrea Cerutti, William C. Olson, Ben Berkhout, James M. Binley, John P. Moore, and Rogier W. Sanders. Targeting HIV-1 Envelope Glycoprotein Trimers to B Cells by Using APRIL Improves Antibody Responses. J. Virol., 86(5):2488-2500, Mar 2012. PubMed ID: 22205734. Show all entries for this paper.

Meyerson2013 Joel R. Meyerson, Erin E. H. Tran, Oleg Kuybeda, Weizao Chen, Dimiter S. Dimitrov, Andrea Gorlani, Theo Verrips, Jeffrey D. Lifson, and Sriram Subramaniam. Molecular Structures of Trimeric HIV-1 Env in Complex with Small Antibody Derivatives. Proc. Natl. Acad. Sci. U.S.A., 110(2):513-518, 8 Jan 2013. PubMed ID: 23267106. Show all entries for this paper.

Moody2010 M. Anthony Moody, Hua-Xin Liao, S. Munir Alam, Richard M. Scearce, M. Kelly Plonk, Daniel M. Kozink, Mark S. Drinker, Ruijun Zhang, Shi-Mao Xia, Laura L. Sutherland, Georgia D. Tomaras, Ian P. Giles, John C. Kappes, Christina Ochsenbauer-Jambor, Tara G. Edmonds, Melina Soares, Gustavo Barbero, Donald N. Forthal, Gary Landucci, Connie Chang, Steven W. King, Anita Kavlie, Thomas N. Denny, Kwan-Ki Hwang, Pojen P. Chen, Philip E. Thorpe, David C. Montefiori, and Barton F. Haynes. Anti-Phospholipid Human Monoclonal Antibodies Inhibit CCR5-Tropic HIV-1 and Induce beta-Chemokines. J. Exp. Med., 207(4):763-776, 12 Apr 2010. PubMed ID: 20368576. Show all entries for this paper.

Moore1993d J. P. Moore, H. Yoshiyama, D. D. Ho, J. E. Robinson, and J. Sodroski. Antigenic Variation in gp120s from Molecular Clones of HIV-1 LAI. AIDS Res. Hum. Retroviruses, 9:1185-1193, 1993. The binding of MAbs to four molecular clones of HIV-1 LAI: HxB2, HxB3, Hx10, and NL4-3, was measured. Despite the close relationship between these clones, there is considerable variation in their antigenic structure, judged by MAb reactivities to the V2, V3, and C4 domains and to discontinuous epitopes. Small variations in sequence can profoundly affect recognition of gp120 by all five groups of defined anti-gp120 neutralizing antibodies. PubMed ID: 7511394. Show all entries for this paper.

Moore1996 J. P. Moore and J. Sodroski. Antibody cross-competition analysis of the human immunodeficiency virus type 1 gp120 exterior envelope glycoprotein. J. Virol., 70:1863-1872, 1996. 46 anti-gp120 monomer MAbs were used to create a competition matrix, and MAb competition groups were defined. The data suggests that there are two faces of the gp120 glycoprotein: a face occupied by the CD4BS, which is presumably also exposed on the oligomeric envelope glycoprotein complex, and a second face which is presumably inaccessible on the oligomer and interacts with a number of nonneutralizing antibodies. PubMed ID: 8627711. Show all entries for this paper.

Moore1998 J. P. Moore and J. Binley. HIV Envelope's Letters Boxed into Shape. Nature, 393:630-631, 1998. Comment on Nature 1998 Jun 18;393(6686):648-59 and Nature 1998 Jun 18;393(6686):705-11. PubMed ID: 9641673. Show all entries for this paper.

Nabatov2004 Alexey A. Nabatov, Georgios Pollakis, Thomas Linnemann, Aletta Kliphius, Moustapha I. M. Chalaby, and William A. Paxton. Intrapatient Alterations in the Human Immunodeficiency Virus Type 1 gp120 V1V2 and V3 Regions Differentially Modulate Coreceptor Usage, Virus Inhibition by CC/CXC Chemokines, Soluble CD4, and the b12 and 2G12 Monoclonal Antibodies. J. Virol., 78(1):524-530, Jan 2004. PubMed ID: 14671134. Show all entries for this paper.

Negi2009 Surendra S. Negi and Werner Braun. Automated Detection of Conformational Epitopes Using Phage Display Peptide Sequences. Bioinform. Biol. Insights, 3:71-81, 2009. PubMed ID: 20140073. Show all entries for this paper.

Nishiyama2009 Yasuhiro Nishiyama, Stephanie Planque, Yukie Mitsuda, Giovanni Nitti, Hiroaki Taguchi, Lei Jin, Jindrich Symersky, Stephane Boivin, Marcin Sienczyk, Maria Salas, Carl V. Hanson, and Sudhir Paul. Toward Effective HIV Vaccination: Induction of Binary Epitope Reactive Antibodies with Broad HIV Neutralizing Activity. J. Biol. Chem., 284(44):30627-30642, 30 Oct 2009. PubMed ID: 19726674. Show all entries for this paper.

Nolan2009 Katrina M. Nolan, Gregory Q. Del Prete, Andrea P. O. Jordan, Beth Haggarty, Josephine Romano, George J. Leslie, and James A. Hoxie. Characterization of a Human Immunodeficiency Virus Type 1 V3 Deletion Mutation That Confers Resistance to CCR5 Inhibitors and the Ability to Use Aplaviroc-Bound Receptor. J. Virol., 83(8):3798-3809, Apr 2009. PubMed ID: 19193800. Show all entries for this paper.

Ohagen2003 Asa Ohagen, Amy Devitt, Kevin J. Kunstman, Paul R. Gorry, Patrick P. Rose, Bette Korber, Joann Taylor, Robert Levy, Robert L. Murphy, Steven M. Wolinsky, and Dana Gabuzda. Genetic and Functional Analysis of Full-Length Human Immunodeficiency Virus Type 1 env Genes Derived from Brain and Blood of Patients with AIDS. J. Virol., 77(22):12336-12345, Nov 2003. PubMed ID: 14581570. Show all entries for this paper.

ORourke2010 Sara M. O'Rourke, Becky Schweighardt, Pham Phung, Dora P. A. J. Fonseca, Karianne Terry, Terri Wrin, Faruk Sinangil, and Phillip W. Berman. Mutation at a Single Position in the V2 Domain of the HIV-1 Envelope Protein Confers Neutralization Sensitivity to a Highly Neutralization-Resistant Virus. J. Virol., 84(21):11200-11209, Nov 2010. PubMed ID: 20702624. Show all entries for this paper.

Oscherwitz1999 J. Oscherwitz, F. M. Gotch, K. B. Cease, and J. A. Berzofsky. New Insights and Approaches Regarding B- and T-Cell Epitopes in HIV Vaccine Design. AIDS, 13(Suppl A):S163-174, 1999. PubMed ID: 10885773. Show all entries for this paper.

Pancera2005 Marie Pancera and Richard Wyatt. Selective Recognition of Oligomeric HIV-1 Primary Isolate Envelope Glycoproteins by Potently Neutralizing Ligands Requires Efficient Precursor Cleavage. Virology, 332(1):145-156, 5 Feb 2005. PubMed ID: 15661147. Show all entries for this paper.

Pancera2005a Marie Pancera, Jacob Lebowitz, Arne Schön, Ping Zhu, Ernesto Freire, Peter D. Kwong, Kenneth H. Roux, Joseph Sodroski, and Richard Wyatt. Soluble Mimetics of Human Immunodeficiency Virus Type 1 Viral Spikes Produced by Replacement of the Native Trimerization Domain with a Heterologous Trimerization Motif: Characterization and Ligand Binding Analysis. J. Virol., 79(15):9954-9969, Aug 2005. PubMed ID: 16014956. Show all entries for this paper.

Pancera2010a Marie Pancera, Shahzad Majeed, Yih-En Andrew Ban, Lei Chen, Chih-chin Huang, Leopold Kong, Young Do Kwon, Jonathan Stuckey, Tongqing Zhou, James E. Robinson, William R. Schief, Joseph Sodroski, Richard Wyatt, and Peter D. Kwong. Structure of HIV-1 gp120 with gp41-Interactive Region Reveals Layered Envelope Architecture and Basis of Conformational Mobility. Proc. Natl. Acad. Sci. U.S.A., 107(3):1166-1171, 19 Jan 2010. PubMed ID: 20080564. Show all entries for this paper.

Pantophlet2003b Ralph Pantophlet, Ian A. Wilson, and Dennis R. Burton. Hyperglycosylated Mutants of Human Immunodeficiency Virus (HIV) Type 1 Monomeric gp120 as Novel Antigens for HIV Vaccine Design. J. Virol., 77(10):5889-8901, May 2003. PubMed ID: 12719582. Show all entries for this paper.

Pantophlet2004 R. Pantophlet, I. A. Wilson, and D. R. Burton. Improved Design of an Antigen with Enhanced Specificity for the Broadly HIV-Neutralizing Antibody b12. Protein Eng. Des. Sel., 17(10):749-758, Oct 2004. PubMed ID: 15542540. Show all entries for this paper.

Pantophlet2006 Ralph Pantophlet and Dennis R. Burton. GP120: Target for Neutralizing HIV-1 Antibodies. Annu. Rev. Immunol., 24:739-769, 2006. PubMed ID: 16551265. Show all entries for this paper.

Pantophlet2009 Ralph Pantophlet, Meng Wang, Rowena O. Aguilar-Sino, and Dennis R. Burton. The Human Immunodeficiency Virus Type 1 Envelope Spike of Primary Viruses Can Suppress Antibody Access to Variable Regions. J. Virol., 83(4):1649-1659, Feb 2009. PubMed ID: 19036813. Show all entries for this paper.

Park2000 E. J. Park, M. K. Gorny, S. Zolla-Pazner, and G. V. Quinnan. A global neutralization resistance phenotype of human immunodeficiency virus type 1 is determined by distinct mechanisms mediating enhanced infectivity and conformational change of the envelope complex. J. Virol., 74:4183-91, 2000. PubMed ID: 10756031. Show all entries for this paper.

Parren1997 P. W. Parren, M. C. Gauduin, R. A. Koup, P. Poignard, Q. J. Sattentau, P. Fisicaro, and D. R. Burton. Erratum to Relevance of the Antibody Response against Human Immunodeficiency Virus Type 1 Envelope to Vaccine Design. Immunol. Lett., 58:125-132, 1997. corrected and republished article originally printed in Immunol. Lett. 1997 Jun;57(1-3):105-112. PubMed ID: 9271324. Show all entries for this paper.

Peters2008a Paul J. Peters, Maria J. Duenas-Decamp, W. Matthew Sullivan, Richard Brown, Chiambah Ankghuambom, Katherine Luzuriaga, James Robinson, Dennis R. Burton, Jeanne Bell, Peter Simmonds, Jonathan Ball, and Paul R. Clapham. Variation in HIV-1 R5 Macrophage-Tropism Correlates with Sensitivity to Reagents that Block Envelope: CD4 Interactions But Not with Sensitivity to Other Entry Inhibitors. Retrovirology, 5:5, 2008. PubMed ID: 18205925. Show all entries for this paper.

Phogat2007 S. Phogat, R. T. Wyatt, and G. B. Karlsson Hedestam. Inhibition of HIV-1 Entry by Antibodies: Potential Viral and Cellular Targets. J. Intern. Med., 262(1):26-43, Jul 2007. PubMed ID: 17598813. Show all entries for this paper.

Pinter2004 Abraham Pinter, William J. Honnen, Yuxian He, Miroslaw K. Gorny, Susan Zolla-Pazner, and Samuel C. Kayman. The V1/V2 Domain of gp120 Is a Global Regulator of the Sensitivity of Primary Human Immunodeficiency Virus Type 1 Isolates to Neutralization by Antibodies Commonly Induced upon Infection. J. Virol., 78(10):5205-5215, May 2004. PubMed ID: 15113902. Show all entries for this paper.

Poignard1996b P. Poignard, T. Fouts, D. Naniche, J. P. Moore, and Q. J. Sattentau. Neutralizing antibodies to human immunodeficiency virus type-1 gp120 induce envelope glycoprotein subunit dissociation. J. Exp. Med., 183:473-484, 1996. Binding of Anti-V3 and the CD4I neutralizing MAbs induces shedding of gp120 on cells infected with the T-cell line-adapted HIV-1 molecular clone Hx10. This was shown by significant increases of gp120 in the supernatant, and exposure of a gp41 epitope that is masked in the oligomer. MAbs binding either to the V2 loop or to CD4BS discontinuous epitopes do not induce gp120 dissociation. This suggests HIV neutralization probably is caused by several mechanisms, and one of the mechanisms may involve gp120 dissociation. PubMed ID: 8627160. Show all entries for this paper.

Poignard2001 P. Poignard, E. O. Saphire, P. W. Parren, and D. R. Burton. gp120: Biologic aspects of structural features. Annu. Rev. Immunol., 19:253--74, 2001. URL: http://immunol.annualreviews.org/cgi/content/full/19/1/253. PubMed ID: 11244037. Show all entries for this paper.

Prevost2017 Jérémie Prévost, Daria Zoubchenok, Jonathan Richard, Maxime Veillette, Beatriz Pacheco, Mathieu Coutu, Nathalie Brassard, Matthew S. Parsons, Kiat Ruxrungtham, Torsak Bunupuradah, Sodsai Tovanabutra, Kwan-Ki Hwang, M. Anthony Moody, Barton F. Haynes, Mattia Bonsignori, Joseph Sodroski, Daniel E. Kaufmann, George M. Shaw, Agnes L. Chenine, and Andrés Finzi. Influence of the Envelope gp120 Phe 43 Cavity on HIV-1 Sensitivity to Antibody-Dependent Cell-Mediated Cytotoxicity Responses. J. Virol., 91(7), 1 Apr 2017. PubMed ID: 28100618. Show all entries for this paper.

Pugach2008 Pavel Pugach, Thomas J. Ketas, Elizabeth Michael, and John P. Moore. Neutralizing Antibody and Anti-Retroviral Drug Sensitivities of HIV-1 Isolates Resistant to Small Molecule CCR5 Inhibitors. Virology, 377(2):401-407, 1 Aug 2008. PubMed ID: 18519143. Show all entries for this paper.

Reeves2005 Jacqueline D. Reeves, Fang-Hua Lee, John L. Miamidian, Cassandra B. Jabara, Marisa M. Juntilla, and Robert W. Doms. Enfuvirtide Resistance Mutations: Impact on Human Immunodeficiency Virus Envelope Function, Entry Inhibitor Sensitivity, and Virus Neutralization. J. Virol., 79(8):4991-4999, Apr 2005. PubMed ID: 15795284. Show all entries for this paper.

Ringe2010 Rajesh Ringe, Madhuri Thakar, and Jayanta Bhattacharya. Variations in Autologous Neutralization and CD4 Dependence of b12 Resistant HIV-1 Clade C env Clones Obtained at Different Time Points from Antiretroviral Naïve Indian Patients with Recent Infection. Retrovirology, 7:76, 2010. PubMed ID: 20860805. Show all entries for this paper.

Rits-Volloch2006 Sophia Rits-Volloch, Gary Frey, Stephen C. Harrison, and Bing Chen. Restraining the Conformation of HIV-1 gp120 by Removing a Flexible Loop. EMBO J., 25(20):5026-5035, 18 Oct 2006. PubMed ID: 17006538. Show all entries for this paper.

Rizzuto1998 C. D. Rizzuto, R. Wyatt, N. Hernandez-Ramos, Y. Sun, P. D. Kwong, W. A. Hendrickson, and J. Sodroski. A Conserved HIV gp120 Glycoprotein Structure Involved in Chemokine Receptor Binding. Science, 280:1949-1953, 1998. This paper compares the epitope for CD4 inducible MAbs with the chemokine co-receptor binding site on the gp120 molecule. Site-directed mutagenesis of YU2 Env was guided by information obtained from the crystallized CD4-17b-gp120 core structure, Kwong et al, 1998. YU2 is a primary macrophage tropic R5 isolate with high affinity for both CD4 and CCR5. A protein with the V1-V2 loops deleted, called wt$\Delta$ was the basis for the assay which detected binding of virus to cells expressing CCR5 in the presence of sCD4. Preincubaton with MAb 17b blocks binding, as did the natural ligand for CCR5, MIP-1$\beta$ and anti-CCR5 MAb 2D7. Mutations 437 P/A and 442 Q/L increased CCR5 binding affinity. The region of gp120 CCR5 binding is shown to be the highly conserved $\beta$-sheet bridging structure, located proximal to the V3 loop. PubMed ID: 9632396. Show all entries for this paper.

Rizzuto2000 Carlo Rizzuto and Joseph Sodroski. Fine Definition of a Conserved CCR5-Binding Region on the Human Immunodeficiency Virus Type 1 Glycoprotein 120. AIDS Res. Hum. Retroviruses, 16(8):741-749, 20 May 2000. PubMed ID: 10826481. Show all entries for this paper.

Robinson1992 J. Robinson, H. Yoshiyama, D. Holton, S. Elliot, and D.D. Ho. Distinct Antigenic Sites on HIV gp120 Identified by a Panel of Human Monoclonal Antibodies. J. Cell Biochem., Suppl 16E:71, 1992. Show all entries for this paper.

Robinson2005 James E. Robinson, Debra Holton Elliott, Effie A. Martin, Kathryne Micken, and Eric S. Rosenberg. High Frequencies of Antibody Responses to CD4 Induced Epitopes in HIV Infected Patients Started on HAART during Acute Infection. Hum Antibodies, 14(3-4):115-121, 2005. PubMed ID: 16720981. Show all entries for this paper.

Ruprecht2011 Claudia R. Ruprecht, Anders Krarup, Lucy Reynell, Axel M. Mann, Oliver F. Brandenberg, Livia Berlinger, Irene A. Abela, Roland R. Regoes, Huldrych F. Günthard, Peter Rusert, and Alexandra Trkola. MPER-Specific Antibodies Induce gp120 Shedding and Irreversibly Neutralize HIV-1. J. Exp. Med., 208(3):439-454, 14 Mar 2011. PubMed ID: 21357743. Show all entries for this paper.

Salzwedel2000 K. Salzwedel, E. D. Smith, B. Dey, and E. A. Berger. Sequential CD4-Coreceptor Interactions in Human Immunodeficiency Virus Type 1 Env Function: Soluble CD4 Activates Env for Coreceptor-Dependent Fusion and Reveals Blocking Activities of Antibodies against Cryptic Conserved Epitopes on gp120. J. Virol., 74:326-333, 2000. PubMed ID: 10590121. Show all entries for this paper.

Sattentau1995a Q. J. Sattentau and J. P. Moore. Human immunodeficiency virus type 1 neutralization is determined by epitope exposure on the gp120 oligomer. J. Exp. Med., 182:185-196, 1995. This study suggests that antibodies specific for one of five different binding regions on gp120 are associated with viral neutralization: V2, V3, C4, the CD4 binding site, and a complex discontinuous epitope that does not interfere with CD4 binding. Kinetic binding properties of a set of MAbs that bind to these regions were studied, analyzing binding to both functional oligomeric LAI gp120 and soluble monomeric LAI BH10 gp120; neutralization ID$_50$s were also evaluated. It was found that the neutralization ID$_50$s was related to the ability to bind oligomeric, not monomeric, gp120, and concluded that with the exception of the V3 loop, regions of gp120 that are immunogenic will be poorly presented on cell-line-adapted virions. Further, the association rate, estimated as the t$_1/2$ to reach equilibrium binding to multimeric, virion associated, gp120, appears to be a major factor relating to affinity and potency of the neutralization response to cell-line-adapted virus. PubMed ID: 7540648. Show all entries for this paper.

Schiffner2016 Torben Schiffner, Natalia de Val, Rebecca A. Russell, Steven W. de Taeye, Alba Torrents de la Peña, Gabriel Ozorowski, Helen J. Kim, Travis Nieusma, Florian Brod, Albert Cupo, Rogier W. Sanders, John P. Moore, Andrew B. Ward, and Quentin J. Sattentau. Chemical Cross-Linking Stabilizes Native-Like HIV-1 Envelope Glycoprotein Trimer Antigens. J. Virol., 90(2):813-828, 28 Oct 2015. PubMed ID: 26512083. Show all entries for this paper.

Schiffner2018 Torben Schiffner, Jesper Pallesen, Rebecca A. Russell, Jonathan Dodd, Natalia de Val, Celia C. LaBranche, David Montefiori, Georgia D. Tomaras, Xiaoying Shen, Scarlett L. Harris, Amin E. Moghaddam, Oleksandr Kalyuzhniy, Rogier W. Sanders, Laura E. McCoy, John P. Moore, Andrew B. Ward, and Quentin J. Sattentau. Structural and Immunologic Correlates of Chemically Stabilized HIV-1 Envelope Glycoproteins. PLoS Pathog., 14(5):e1006986, May 2018. PubMed ID: 29746590. Show all entries for this paper.

Schulke2002 Norbert Schulke, Mika S. Vesanen, Rogier W. Sanders, Ping Zhu, Min Lu, Deborah J. Anselma, Anthony R. Villa, Paul W. H. I. Parren, James M. Binley, Kenneth H. Roux, Paul J. Maddon, John P. Moore, and William C. Olson. Oligomeric and Conformational Properties of a Proteolytically Mature, Disulfide-Stabilized Human Immunodeficiency Virus Type 1 gp140 Envelope Glycoprotein. J. Virol., 76(15):7760-76, Aug 2002. PubMed ID: 12097589. Show all entries for this paper.

Seaman2010 Michael S. Seaman, Holly Janes, Natalie Hawkins, Lauren E. Grandpre, Colleen Devoy, Ayush Giri, Rory T. Coffey, Linda Harris, Blake Wood, Marcus G. Daniels, Tanmoy Bhattacharya, Alan Lapedes, Victoria R Polonis, Francine E. McCutchan, Peter B. Gilbert, Steve G. Self, Bette T. Korber, David C. Montefiori, and John R. Mascola. Tiered Categorization of a Diverse Panel of HIV-1 Env Pseudoviruses for Assessment of Neutralizing Antibodies. J Virol, 84(3):1439-1452, Feb 2010. PubMed ID: 19939925. Show all entries for this paper.

Sellhorn2012 George Sellhorn, Zane Kraft, Zachary Caldwell, Katharine Ellingson, Christine Mineart, Michael S. Seaman, David C. Montefiori, Eliza Lagerquist, and Leonidas Stamatatos. Engineering, Expression, Purification, and Characterization of Stable Clade A/B Recombinant Soluble Heterotrimeric gp140 Proteins. J. Virol., 86(1):128-142, Jan 2012. PubMed ID: 22031951. Show all entries for this paper.

Selvarajah2005 Suganya Selvarajah, Bridget Puffer, Ralph Pantophlet, Mansun Law, Robert W. Doms, and Dennis R. Burton. Comparing Antigenicity and Immunogenicity of Engineered gp120. J. Virol., 79(19):12148-12163, Oct 2005. PubMed ID: 16160142. Show all entries for this paper.

Sharma2006 Victoria A. Sharma, Elaine Kan, Yide Sun, Ying Lian, Jimna Cisto, Verna Frasca, Susan Hilt, Leonidas Stamatatos, John J. Donnelly, Jeffrey B. Ulmer, Susan W. Barnett, and Indresh K. Srivastava. Structural Characteristics Correlate with Immune Responses Induced by HIV Envelope Glycoprotein Vaccines. Virology, 10 Jun 2006. PubMed ID: 16769099. Show all entries for this paper.

Shen2010 Xiaoying Shen, S. Moses Dennison, Pinghuang Liu, Feng Gao, Frederick Jaeger, David C. Montefiori, Laurent Verkoczy, Barton F. Haynes, S. Munir Alam, and Georgia D. Tomaras. Prolonged Exposure of the HIV-1 gp41 Membrane Proximal Region with L669S Substitution. Proc. Natl. Acad. Sci. U.S.A., 107(13):5972-5977, 30 Mar 2010. PubMed ID: 20231447. Show all entries for this paper.

Shibata2007 Junji Shibata, Kazuhisa Yoshimura, Akiko Honda, Atsushi Koito, Toshio Murakami, and Shuzo Matsushita. Impact of V2 Mutations on Escape from a Potent Neutralizing Anti-V3 Monoclonal Antibody during In Vitro Selection of a Primary Human Immunodeficiency Virus Type 1 Isolate. J. Virol., 81(8):3757-3768, Apr 2007. PubMed ID: 17251298. Show all entries for this paper.

Si2001 Zhihai Si, Mark Cayabyab, and Joseph Sodroski. Envelope Glycoprotein Determinants of nEutralization Resistance in a Simian-Human Immunodeficiency Virus (SHIV-HXBc2P 3.2) Derived by Passage in Monkeys. J. Virol., 75(9):4208-4218, May 2001. PubMed ID: 11287570. Show all entries for this paper.

Smalls-Mantey2012 Adjoa Smalls-Mantey, Nicole Doria-Rose, Rachel Klein, Andy Patamawenu, Stephen A. Migueles, Sung-Youl Ko, Claire W. Hallahan, Hing Wong, Bai Liu, Lijing You, Johannes Scheid, John C. Kappes, Christina Ochsenbauer, Gary J. Nabel, John R. Mascola, and Mark Connors. Antibody-Dependent Cellular Cytotoxicity against Primary HIV-Infected CD4+ T Cells Is Directly Associated with the Magnitude of Surface IgG Binding. J. Virol., 86(16):8672-8680, Aug 2012. PubMed ID: 22674985. Show all entries for this paper.

Srivastava2002 Indresh K. Srivastava, Leonidas Stamatatos, Harold Legg, Elaine Kan, Anne Fong, Stephen R. Coates, Louisa Leung, Mark Wininger, John J. Donnelly, Jeffrey B. Ulmer, and Susan W. Barnett. Purification and Characterization of Oligomeric Envelope Glycoprotein from a Primary R5 Subtype B Human Immunodeficiency Virus. J. Virol., 76(6):2835-2847, Mar 2002. URL: http://jvi.asm.org/cgi/content/full/76/6/2835. PubMed ID: 11861851. Show all entries for this paper.

Srivastava2005 Indresh K. Srivastava, Jeffrey B. Ulmer, and Susan W. Barnett. Role of Neutralizing Antibodies in Protective Immunity Against HIV. Hum. Vaccin., 1(2):45-60, Mar-Apr 2005. PubMed ID: 17038830. Show all entries for this paper.

Srivastava2008 Indresh K. Srivastava, Elaine Kan, Yide Sun, Victoria A. Sharma, Jimna Cisto, Brian Burke, Ying Lian, Susan Hilt, Zohar Biron, Karin Hartog, Leonidas Stamatatos, Ruben Diaz-Avalos, R Holland Cheng, Jeffrey B. Ulmer, and Susan W. Barnett. Comparative Evaluation of Trimeric Envelope Glycoproteins Derived from Subtype C and B HIV-1 R5 Isolates. Virology, 372(2):273-290, 15 Mar 2008. PubMed ID: 18061231. Show all entries for this paper.

Stamatatos1998 L. Stamatatos and C. Cheng-Mayer. An Envelope Modification That Renders a Primary, Neutralization-Resistant Clade B Human Immunodeficiency Virus Type 1 Isolate Highly Susceptible to Neutralization by Sera from Other Clades. J. Virol., 72:7840-7845, 1998. PubMed ID: 9733820. Show all entries for this paper.

Stamatatos2000 L. Stamatatos, M. Lim, and C. Cheng-Mayer. Generation and structural analysis of soluble oligomeric gp140 envelope proteins derived from neutralization-resistant and neutralization-susceptible primary HIV type 1 isolates. AIDS Res. Hum. Retroviruses, 16(10):981--94, 1 Jul 2000. PubMed ID: 10890360. Show all entries for this paper.

Stanfield2005 Robyn L. Stanfield and Ian A. Wilson. Structural Studies of Human HIV-1 V3 Antibodies. Hum Antibodies, 14(3-4):73-80, 2005. PubMed ID: 16720977. Show all entries for this paper.

Stricher2008 François Stricher, Chih-chin Huang, Anne Descours, Sophie Duquesnoy, Olivier Combes, Julie M. Decker, Young Do Kwon, Paolo Lusso, George M. Shaw, Claudio Vita, Peter D. Kwong, and Loïc Martin. Combinatorial Optimization of a CD4-Mimetic Miniprotein and Cocrystal Structures with HIV-1 gp120 Envelope Glycoprotein. J. Mol. Biol., 382(2):510-524, 3 Oct 2008. PubMed ID: 18619974. Show all entries for this paper.

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Sullivan1998b N. Sullivan, Y. Sun, J. Binley, J. Lee, C. F. Barbas III, P. W. H. I. Parren, D. R. Burton, and J. Sodroski. Determinants of human immunodeficiency virus type 1 envelope glycoprotein activation by soluble CD4 and monoclonal antibodies. J. Virol., 72:6332-8, 1998. PubMed ID: 9658072. Show all entries for this paper.

Sundling2012 Christopher Sundling, Yuxing Li, Nick Huynh, Christian Poulsen, Richard Wilson, Sijy O'Dell, Yu Feng, John R. Mascola, Richard T. Wyatt, and Gunilla B. Karlsson Hedestam. High-Resolution Definition of Vaccine-Elicited B Cell Responses Against the HIV Primary Receptor Binding Site. Sci. Transl. Med., 4(142):142ra96, 11 Jul 2012. PubMed ID: 22786681. Show all entries for this paper.

Tan2009 Hepan Tan and A. J. Rader. Identification of Putative, Stable Binding Regions through Flexibility Analysis of HIV-1 gp120. Proteins, 74(4):881-894, Mar 2009. PubMed ID: 18704932. Show all entries for this paper.

Tanaka2017 Kazuki Tanaka, Takeo Kuwata, Muntasir Alam, Gilad Kaplan, Shokichi Takahama, Kristel Paola Ramirez Valdez, Anna Roitburd-Berman, Jonathan M. Gershoni, and Shuzo Matsushita. Unique binding modes for the broad neutralizing activity of single-chain variable fragments (scFv) targeting CD4-induced epitopes. Retrovirology, 14(1):44 doi, Sep 2017. PubMed ID: 28938888 Show all entries for this paper.

Tang2011 Haili Tang, James E. Robinson, S. Gnanakaran, Ming Li, Eric S. Rosenberg, Lautaro G. Perez, Barton F. Haynes, Hua-Xin Liao, Celia C. Labranche, Bette T. Korber, and David C. Montefiori. Epitopes Immediately below the Base of the V3 Loop of gp120 as Targets for the Initial Autologous Neutralizing Antibody Response in Two HIV-1 Subtype B-Infected Individuals. J. Virol., 85(18):9286-9299, Sep 2011. PubMed ID: 21734041. Show all entries for this paper.

Taylor2008 Brian M. Taylor, J. Scott Foulke, Robin Flinko, Alonso Heredia, Anthony DeVico, and Marvin Reitz. An Alteration of Human Immunodeficiency Virus gp41 Leads to Reduced CCR5 Dependence and CD4 Independence. J. Virol., 82(11):5460-5471, Jun 2008. PubMed ID: 18353949. Show all entries for this paper.

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Thali1994 M. Thali, M. Charles, C. Furman, L. Cavacini, M. Posner, J. Robinson, and J. Sodroski. Resistance to Neutralization by Broadly Reactive Antibodies to the Human Immunodeficiency Virus Type 1 gp120 Glycoprotein Conferred by a gp41 Amino Acid Change. J. Virol., 68:674-680, 1994. A T->A amino acid substitution at position 582 of gp41 conferred resistance to neutralization to 30\% of HIV positive sera (Wilson et al. J Virol 64:3240-48 (1990)). Monoclonal antibodies that bound to the CD4 binding site were unable to neutralize this virus, but the mutation did not reduce the neutralizing capacity of a V2 region MAb G3-4, V3 region MAbs, or gp41 neutralizing MAb 2F5. PubMed ID: 7507184. Show all entries for this paper.

Thida2019 Win Thida, Takeo Kuwata, Yosuke Maeda, Tetsu Yamashiro, Giang Van Tran, Kinh Van Nguyen, Masafumi Takiguchi, Hiroyuki Gatanaga, Kazuki Tanaka, and Shuzo Matsushita. The role of conventional antibodies targeting the CD4 binding site and CD4-induced epitopes in the control of HIV-1 CRF01_AE viruses. Biochem Biophys Res Commun, 508(1):46-51 doi, Jan 2019. PubMed ID: 30470571 Show all entries for this paper.

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vanMontfort2008 Thijs van Montfort, Adri A. M. Thomas, Georgios Pollakis, and William A. Paxton. Dendritic Cells Preferentially Transfer CXCR4-Using Human Immunodeficiency Virus Type 1 Variants to CD4+ T Lymphocytes in trans. J. Viro.l, 82(16):7886-7896, Aug 2008. PubMed ID: 18524826. Show all entries for this paper.

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White2010 Tommi A. White, Alberto Bartesaghi, Mario J. Borgnia, Joel R. Meyerson, M. Jason V. de la Cruz, Julian W. Bess, Rachna Nandwani, James A. Hoxie, Jeffrey D. Lifson, Jacqueline L. S. Milne, and Sriram Subramaniam. Molecular Architectures of Trimeric SIV and HIV-1 Envelope Glycoproteins on Intact Viruses: Strain-Dependent Variation in Quaternary Structure. PLoS Pathog, 6(12):e1001249, 2010. PubMed ID: 21203482. Show all entries for this paper.

White2011 Tommi A. White, Alberto Bartesaghi, Mario J. Borgnia, M. Jason V. de la Cruz, Rachna Nandwani, James A. Hoxie, Julian W. Bess, Jeffrey D. Lifson, Jacqueline L. S. Milne, and Sriram Subramaniam. Three-Dimensional Structures of Soluble CD4-Bound States of Trimeric Simian Immunodeficiency Virus Envelope Glycoproteins Determined by Using Cryo-Electron Tomography. J. Virol., 85(23):12114-12123, Dec 2011. PubMed ID: 21937655. Show all entries for this paper.

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Witt2017 Kristen C. Witt, Luis Castillo-Menendez, Haitao Ding, Nicole Espy, Shijian Zhang, John C. Kappes, and Joseph Sodroski. Antigenic Characterization of the Human Immunodeficiency Virus (HIV-1) Envelope Glycoprotein Precursor Incorporated into Nanodiscs. PLoS One, 12(2):e0170672, 2017. PubMed ID: 28151945. Show all entries for this paper.

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Wu2009a Lan Wu, Tongqing Zhou, Zhi-yong Yang, Krisha Svehla, Sijy O'Dell, Mark K. Louder, Ling Xu, John R. Mascola, Dennis R. Burton, James A. Hoxie, Robert W. Doms, Peter D. Kwong, and Gary J. Nabel. Enhanced Exposure of the CD4-Binding Site to Neutralizing Antibodies by Structural Design of a Membrane-Anchored Human Immunodeficiency Virus Type 1 gp120 Domain. J. Virol., 83(10):5077-5086, May 2009. PubMed ID: 19264769. Show all entries for this paper.

Wu2010 Xueling Wu, Zhi-Yong Yang, Yuxing Li, Carl-Magnus Hogerkorp, William R. Schief, Michael S. Seaman, Tongqing Zhou, Stephen D. Schmidt, Lan Wu, Ling Xu, Nancy S. Longo, Krisha McKee, Sijy O'Dell, Mark K. Louder, Diane L. Wycuff, Yu Feng, Martha Nason, Nicole Doria-Rose, Mark Connors, Peter D. Kwong, Mario Roederer, Richard T. Wyatt, Gary J. Nabel, and John R. Mascola. Rational Design of Envelope Identifies Broadly Neutralizing Human Monoclonal Antibodies to HIV-1. Science, 329(5993):856-861, 13 Aug 2010. PubMed ID: 20616233. Show all entries for this paper.

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Wyatt1997 R. Wyatt, E. Desjardin, U. Olshevsky, C. Nixon, J. Binley, V. Olshevsky, and J. Sodroski. Analysis of the Interaction of the Human Immunodeficiency Virus Type 1 gp120 Envelope Glycoprotein with the gp41 Transmembrane Glycoprotein. J. Virol., 71:9722-9731, 1997. This study characterized the binding of gp120 and gp41 by comparing Ab reactivity to soluble gp120 and to a soluble complex of gp120 and gp41 called sgp140. The occlusion of gp120 epitopes in the sgp140 complex provides a guide to the gp120 domains that interact with gp41, localizing them in C1 and C5 of gp120. Mutations that disrupt the binding of the occluded antibodies do not influence NAb binding or CD4 binding, thus if the gp41 binding domain is deleted, the immunologically desirable features of gp120 for vaccine design are still intact. PubMed ID: 9371638. Show all entries for this paper.

Wyatt1998 R. Wyatt, P. D. Kwong, E. Desjardins, R. W. Sweet, J. Robinson, W. A. Hendrickson, and J. G. Sodroski. The Antigenic Structure of the HIV gp120 Envelope Glycoprotein. Nature, 393:705-711, 1998. Comment in Nature 1998 Jun 18;393(6686):630-1. The spatial organization of the neutralizing epitopes of gp120 is described, based on epitope maps interpreted in the context of the X-ray crystal structure of a ternary complex that includes a gp120 core, CD4 and a neutralizing antibody. PubMed ID: 9641684. Show all entries for this paper.

Xiang2002 Shi-Hua. Xiang, Peter D. Kwong, Rishi Gupta, Carlo D. Rizzuto, David J. Casper, Richard Wyatt, Liping Wang, Wayne A. Hendrickson, Michael L. Doyle, and Joseph Sodroski. Mutagenic Stabilization and/or Disruption of a CD4-Bound State Reveals Distinct Conformations of the Human Immunodeficiency Virus Type 1 gp120 Envelope Glycoprotein. J. Virol., 76(19):9888-9899, Oct 2002. PubMed ID: 12208966. Show all entries for this paper.

Xiang2002b Shi-Hua Xiang, Najah Doka, Rabeéea K. Choudhary, Joseph Sodroski, and James E. Robinson. Characterization of CD4-Induced Epitopes on the HIV Type 1 gp120 Envelope Glycoprotein Recognized by Neutralizing Human Monoclonal Antibodies. AIDS Res. Hum. Retroviruses, 18(16):1207-1217, 1 Nov 2002. PubMed ID: 12487827. Show all entries for this paper.

Xiang2003 Shi-Hua Xiang, Liping Wang, Mariam Abreu, Chih-Chin Huang, Peter D. Kwong, Eric Rosenberg, James E. Robinson, and Joseph Sodroski. Epitope Mapping and Characterization of a Novel CD4-Induced Human Monoclonal Antibody Capable of Neutralizing Primary HIV-1 Strains. Virology, 315(1):124-134, 10 Oct 2003. PubMed ID: 14592765. Show all entries for this paper.

Xu2013 Xiao-Hong Nancy Xu, Zhaoyang Wen, and William J. Brownlow. Ultrasensitive Analysis of Binding Affinity of HIV Receptor and Neutralizing Antibody Using Solution-Phase Electrochemiluminescence Assay. J. Electroanal. Chem. (Lausanne), 688:53-60, 1 Jan 2013. PubMed ID: 23565071. Show all entries for this paper.

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Yang2002 Xinzhen Yang, Juliette Lee, Erin M. Mahony, Peter D. Kwong, Richard Wyatt, and Joseph Sodroski. Highly Stable Trimers Formed by Human Immunodeficiency Virus Type 1 Envelope Glycoproteins Fused with the Trimeric Motif of T4 Bacteriophage Fibritin. J. Virol., 76(9):4634-4642, 1 May 2002. PubMed ID: 11932429. Show all entries for this paper.

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Yoshimura2006 Kazuhisa Yoshimura, Junji Shibata, Tetsuya Kimura, Akiko Honda, Yosuke Maeda, Atsushi Koito, Toshio Murakami, Hiroaki Mitsuya, and Shuzo Matsushita. Resistance Profile of a Neutralizing Anti-HIV Monoclonal Antibody, KD-247, that Shows Favourable Synergism with Anti-CCR5 Inhibitors. AIDS, 20(16):2065-2073, 24 Oct 2006. PubMed ID: 17053352. Show all entries for this paper.

Yoshimura2010 Kazuhisa Yoshimura, Shigeyoshi Harada, Junji Shibata, Makiko Hatada, Yuko Yamada, Chihiro Ochiai, Hirokazu Tamamura, and Shuzo Matsushita. Enhanced Exposure of Human Immunodeficiency Virus Type 1 Primary Isolate Neutralization Epitopes through Binding of CD4 Mimetic Compounds. J. Virol., 84(15):7558-7568, Aug 2010. PubMed ID: 20504942. Show all entries for this paper.

Yuan2005 Wen Yuan, Stewart Craig, Xinzhen Yang, and Joseph Sodroski. Inter-Subunit Disulfide Bonds in Soluble HIV-1 Envelope Glycoprotein Trimers. Virology, 332(1):369-383, 5 Feb 2005. PubMed ID: 15661168. Show all entries for this paper.

Yuan2006 Wen Yuan, Jessica Bazick, and Joseph Sodroski. Characterization of the Multiple Conformational States of Free Monomeric and Trimeric Human Immunodeficiency Virus Envelope Glycoproteins after Fixation by Cross-Linker. J. Virol., 80(14):6725-6737, Jul 2006. PubMed ID: 16809278. Show all entries for this paper.

Zhang2001a W. Zhang, A. P. Godillot, R. Wyatt, J. Sodroski, and I. Chaiken. Antibody 17b Binding at the Coreceptor Site Weakens the Kinetics of the Interaction of Envelope Glycoprotein gp120 with CD4. Biochemistry, 40(6):1662-1670, 13 Feb 2001. PubMed ID: 11327825. Show all entries for this paper.

Zhang2002 Peng Fei Zhang, Peter Bouma, Eun Ju Park, Joseph B. Margolick, James E. Robinson, Susan Zolla-Pazner, Michael N. Flora, and Gerald V. Quinnan, Jr. A Variable Region 3 (V3) Mutation Determines a Global Neutralization Phenotype and CD4-Independent Infectivity of a Human Immunodeficiency Virus Type 1 Envelope Associated with a Broadly Cross-Reactive, Primary Virus-Neutralizing Antibody Response. J. Virol., 76(2):644-655, Jan 2002. PubMed ID: 11752155. Show all entries for this paper.

Zhang2010 Mei-Yun Zhang, Andrew Rosa Borges, Roger G. Ptak, Yanping Wang, Antony S. Dimitrov, S. Munir Alam, Lindsay Wieczorek, Peter Bouma, Timothy Fouts, Shibo Jiang, Victoria R. Polonis, Barton F. Haynes, Gerald V. Quinnan, David C. Montefiori, and Dimiter S. Dimitrov. Potent and Broad Neutralizing Activity of a Single Chain Antibody Fragment against Cell-Free and Cell-Associated HIV-1. mAbs, 2(3):266-274, May-Jun 2010. PubMed ID: 20305395. Show all entries for this paper.

Zhou2007 Tongqing Zhou, Ling Xu, Barna Dey, Ann J. Hessell, Donald Van Ryk, Shi-Hua Xiang, Xinzhen Yang, Mei-Yun Zhang, Michael B. Zwick, James Arthos, Dennis R. Burton, Dimiter S. Dimitrov, Joseph Sodroski, Richard Wyatt, Gary J. Nabel, and Peter D. Kwong. Structural Definition of a Conserved Neutralization Epitope on HIV-1 gp120. Nature, 445(7129):732-737, 15 Feb 2007. PubMed ID: 17301785. Show all entries for this paper.

Zhou2010 Tongqing Zhou, Ivelin Georgiev, Xueling Wu, Zhi-Yong Yang, Kaifan Dai, Andrés Finzi, Young Do Kwon, Johannes F. Scheid, Wei Shi, Ling Xu, Yongping Yang, Jiang Zhu, Michel C. Nussenzweig, Joseph Sodroski, Lawrence Shapiro, Gary J. Nabel, John R. Mascola, and Peter D. Kwong. Structural Basis for Broad and Potent Neutralization of HIV-1 by Antibody VRC01. Science, 329(5993):811-817, 13 Aug 2010. PubMed ID: 20616231. Show all entries for this paper.

Zhu2003 Chongbin Zhu, Thomas J. Matthews, and Chin Ho Chen. Neutralization Epitopes of the HIV-1 Primary Isolate DH012. Vaccine, 21(23):3301-3306, 4 Jul 2003. PubMed ID: 12804861. Show all entries for this paper.

Zwick2003a Michael B. Zwick, Robert Kelleher, Richard Jensen, Aran F. Labrijn, Meng Wang, Gerald V. Quinnan, Jr., Paul W. H. I. Parren, and Dennis R. Burton. A Novel Human Antibody against Human Immunodeficiency Virus Type 1 gp120 Is V1, V2, and V3 Loop Dependent and Helps Delimit the Epitope of the Broadly Neutralizing Antibody Immunoglobulin G1 b12. J. Virol., 77(12):6965-6978, Jun 2003. PubMed ID: 12768015. Show all entries for this paper.

Displaying record number 659

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MAb ID	48d (4.8d, 4.8D, 48D)
HXB2 Location	Env	Env Epitope Map
Author Location	gp120
Research Contact	James Robinson, Tulane University, New Orleans, LA, USA
Epitope
Ab Type	gp120 CD4i
Neutralizing	L P (weak) View neutralization details
Contacts and Features	View contacts and features
Species (Isotype)	human(IgG1κ)
Patient
Immunogen	HIV-1 infection
Keywords	ADCC, antibody binding site, antibody interactions, antibody lineage, antibody polyreactivity, antibody sequence, assay or method development, autoantibody or autoimmunity, binding affinity, co-receptor, dendritic cells, drug resistance, escape, glycosylation, HAART, ART, kinetics, mimics, neutralization, review, structure, subtype comparisons, vaccine antigen design, vaccine-induced immune responses, variant cross-reactivity

Notes

Showing 103 of 103 notes.

48d: Assays of poly- and autoreactivity demonstrated that broadly neutralizing NAbs are significantly more poly- and autoreactive than non-neutralizing NAbs. 48d is neither autoreactive nor polyreactive. Liu2015a (autoantibody or autoimmunity, antibody polyreactivity)
48d: Three strategies were applied to perturb the structure of Env in order to make the protein more susceptible to neutralization: exposure to cold, Env-activating ligands, and a chaotropic agent. A panel of mAbs (E51, 48d, 17b, 3BNC176, 19b, 447-52D, 39F, b12, b6, PG16, PGT145, PGT126, 35O22, F240, 10E8, 7b2, 2G12) was used to test the neutralization resistance of a panel of subtype B and C pseudoviruses with and without these agents. Both cold and CD4 mimicking agents (CD4Ms) increased the sensitivity of some viruses. The chaotropic agent urea had little effect by itself, but could enhance the effects of cold or CD4Ms. Thus Env destabilizing agents can make Env more susceptible to neutralization and may hold promise as priming vaccine antigens. Johnson2017 (vaccine antigen design)
48d: 15e: This study investigated the ability of native, membrane-expressed JR-FL Env trimers to elicit NAbs. Rabbits were immunized with virus-like particles (VLPs) expressing trimers (trimer VLP sera) and DNA expressing native Env trimer, followed by a protein boost (DNA trimer sera). N197 glycan- and residue 230- removal conferred sensitivity to Trimer VLP sera and DNA trimer sera respectively, showing for the first time that strain-specific holes in the "glycan fence" can allow the development of tier 2 NAbs to native spikes. All 3 sera neutralized via quaternary epitopes and exploited natural gaps in the glycan defenses of the second conserved region of JR-FL gp120. N197 glycan mutants were tested against 48d showing a loss of tier 2 phenotype. The results are in Table S5. Crooks2015 (glycosylation, neutralization)
48d: A highly conserved mechanism of exposure of ADCC epitopes on Env is reported, showing that binding of Env and CD4 within the same HIV-1 infected cell effectively exposes these epitopes. The mechanism might explain the evolutionary advantage of downregulation of cell surface CD4v by the Vpu and Nef proteins. 48d was used in CD4 coexpression and competitive binding assay. Veillette2014 (ADCC)
48d:X-ray crystallography, surface plasmon resonance and pseudovirus neutralization were used to characterize a heavy chain only llama antibody, named JM4. The full-length IgG2b version of JM4 neutralizes over 95% of circulating HIV-1 isolates. JM4 targets a hybrid epitope on gp120 that combines elements from both the CD4 binding region and the coreceptor binding surface. JM4 epitope overlaps with the CD4i binding site of 48d. Acharya2013 (neutralization)
48d: The complexity of the epitopes recognized by ADCC responses in HIV-1 infected individuals and candidate vaccine recipients is discussed in this review. 48d was discussed as CD4i recognizing and neutralizing anti-gp120 mAb similar to 17b. Pollara2013 (ADCC, review)
48D: The sera of 20 HIV-1 patients were screened for ADCC in a novel assay measuring granzyme B (GrB) and T cell elimination and reported that complex sera mediated greater levels of ADCC than anti-HIV mAbs. The data suggested that total amount of IgG bound is an important determinant of robust ADCC which improves the vaccine potency. 48D was used as an anti-CD4 binding Ab to study effects of Ab specificity and affinity on ADCC against HIV-1 infected targets. Smalls-Mantey2012 (ADCC, assay or method development)
48d: Isolation of VRC06 and VRC06b MAbs from a slow progressor donor 45 is reported. This is the same donor from whom bnMAbs VRC01, VRC03 and NIH 45-46 were isolated and the new MAbs are clonal variants of VRC03. 48d was used as a CoRB-specific MAb to compare binding specificity of VRC06. Li2012
48D: This study reports that most bnAbs require somatic mutations in the FWRs which provides flexibility, increasing breadth and potency. To determine the consequence of FWR mutations the framework residues were reverted to the Ab's germline counterpart (FWR-GL) and binding and neutralizing properties were then evaluated. 48D was used in comparing the Ab framework amino acid replacement vs. interactive surface area on Ab. Klein2013 (neutralization, structure, antibody lineage)
48d: Intrinsic reactivity of HIV-1, a new property regulating the level of both entry and sensitivity to Abs has been reported. This activity dictates the level of responsiveness of Env protein to co-receptor, CD4 engagement and Abs. CD4 independence of the glycoprotein variants exhibits strong correlation with 48d binding.The N197S change influence 48d binding to CD4. Haim2011 (antibody interactions)
48d: The study used the swarm of quasispecies representing Env protein variants to identify mutants conferring sensitivity and resistance to BnAbs. Libraries of Env proteins were cloned and in vitro mutagenesis was used to identify the specific AA responsible for altered neutralization/resistance, which appeared to be associated with conformational changes and exposed epitopes in different regions of gp160. The result showed that sequences in gp41, the CD4bs, and V2 domain act as global regulator of neutralization sensitivity. 48d was used as BnAb to screen Env clones. N197H mutation didn't have any effect on 48d neutralization. ORourke2012 (neutralization)
48d: A panel of glycan deletion mutants was created by point mutation into HIV gp160, showing that glycans are important targets on HIV-1 glycoproteins for broad neutralizing responses in vivo. Enrichment of high mannose N-linked glycan(HM-glycan) of HIV-1 glycoprotein enhanced neutralizing activity of sera from 8/9 patients. 48d was used as a control to compare the neutralizing activity of patients' sera. Kifunensine, a plant alkaloid treatment of HIV-1 resulted in reduction of neutralization sensitivity to 48d. Lavine2012 (neutralization)
48d: To improve the immunogenicity of HIV-1 Env vaccines, a chimeric gp140 trimer in which V1V2 region was replaced by the GM-CSF cytokine was constructed. We selected GM-CSF was selected because of its defined adjuvant activity. Chimeric EnvGM-CSF protein enhanced Env-specific Ab and T cell responses in mice compared with wild-type Env. Probing with neutralizing antibodies showed that both the Env and GM-CSF components of the chimeric protein were folded correctly. 3 proteins were studied: Env-wild-type, Env-ΔV1V2, Env-hGM-CSF. In the absence of CD4, the CD4i epitope MAb 17b, 48d, and 412d bound poorly to Env-wild-type and Env-hGM-CSF but efficiently to Env-ΔV1V2. Adding soluble CD4 substantially increased the binding of these MAb to Env-ΔV1V2 and especially to Env-wild-type, but binding to Env-hGM-CSF was improved only modestly, suggesting that the presence of GM-CSF in the V1V2 region either limits the accessibility of the CD4i epitopes or blocks the conformational changes that expose them. vanMontfort2011 (vaccine antigen design)
48d: Small sized CD4 mimetics (miniCD4s) were engineered. These miniCD4s by themselves are poorly immunogenic and do not induce anti-CD4 antibodies. Stable covalent complexes between miniCD4s and gp120 and gp140 were generated through a site-directed coupling reaction. These complexes were recognized by CD4i antibodies as well as by the HIV co-receptor CCR5 and elicited CD4i antibody responses in rabbits. A panel of MAbs of defined epitope specificities, including MAb 48d, was used to analyze the antigenic integrity of the covalent complexes using capture ELISA. Martin2011 (mimics, binding affinity)
48d: Broadly neutralizing HIV-1 immunity associated with VRC01-like antibodies was studied by isolation of VRC01-like neutralizers with CD4bs probe; structural definition of gp120 recognition by RSC3-identified antibodies from different donors; functional complementation of heavy and light chains among VRC01-like antibodies; identification of VRC01 antibodies by 454 pyrosequencing; and cross-donor phylogenetic analysis of sequences derived from the same precursor germline gene. 48d had 43-72% sequence identity of its heavy and light chains to respective chains of VRC-PG04 and VRC-CH31. Wu2011 (structure)
48d: This review outlines the general structure of the gp160 viral envelope, the dynamics of viral entry, the evolution of humoral response, the mechanisms of viral escape and the characterization of broadly neutralizing Abs. This MAb is noted in the review to be CD4i antibody and to have weak neutralizing activity against most HIV-1 isolates, with increased activity when soluble CD4 is added. Gonzalez2010 (neutralization, variant cross-reactivity, escape, review)
48d: Crystal structures of gp120 and gp41 in complex with CD4 and/or MAbs 17b, 48d, b12, b13, 412d, X5, 211C, C11, 15e, m6, m9 and F105 were used to determine the structure and the mobility of the gp41-interactive region of gp120. Elements determined to maintain the gp120-gp41 interaction were the gp120 termini and a newly described invariant 7-stranded β-sandwich. Structurally plastic elements of gp120 responsible for the various gp120 conformation changes due to receptor- or Ab-binding were structured into 3 layers, with the V1/V2 loops emanating from layer 2 and the highly glycosylated outer domain from layer 3. Pancera2010a (antibody binding site, structure)
48d: A mathematical framework is designed to determine the number of Abs required to neutralize a single trimer called the stoichiometry of trimer neutralization. 15 different virus antibody combinations divided into five groups based on antibody binding sites were used in the designed model. 48d was classified into CD4i group as it binds CD4. The number of 48d Abs needed to neutralize a single trimer was determined to equal 1 with 99.8% probability. Magnus2010
48d: Impact of in vivo Env-CD4 interactions was studied during vaccinations of Rhesus macaques with two Env trimer variants rendered CD4 binding defective (368D/R and 423/425/431 trimers) and wild-type (WT) trimers. Ab binding profiles of the three trimer variants were assessed by binding analyses to different MAbs. coreceptor binding site (CoRbs) directed MAb 48d bound similarly to WT and 368D/R trimers but its binding affinity was completely abrogated for 423/425/431 trimers. Douagi2010 (binding affinity)
48d: A set of Env variants with deletions in V1/V2 was constructed. Replication competent Env variants with V1/V2 deletions were obtained using virus evolution of V1/V2 deleted variants. Sensitivity of the evolved ΔV1V2 viruses was evaluated to study accessibility of their neutralization epitopes. 48d neutralized ΔV1V2 variants more potently than the full-length trimer. 48d bound better to the cleaved ΔV1V2 trimers than to the full-length trimer. Addition of sCD4 did not enhance 412d binding, as it was close to optimal without sCD4. However, 48d did not bind well to the uncleaved ΔV1V2 trimers nor to the full-length trimers in the absence of sCD4, but the binding was enhanced by addition of sCD4. 48d did not bind a ΔV1V2 virus carrying V120K substitution. Binding analyses of other CD4i Abs yielded slightly different results, indicating that various CD4i epitopes may be shielded to slightly different extents by the V1V2 domain. Bontjer2010 (neutralization, binding affinity)
48d: GPI-anchored and secretory scFvs of 48d were generated. GPI-scFvs were localized in the lipid raft of the plasma membrane. Cells transduced with the secretory 48d scFv did not show neutralization breadth and potency against 11 tested pseudotype viruses belonging to clades A, B, B', C and E, nor against 6 wild type HIV-1 strains. GPI-anchored scFvs of 48d neutralized all 11 HIV-1 pseudotypes, with great degree of potency against clades A, B, B' and E, and less potent against clade C. 48d GPI-scFv neutralized 4/6 HIV-1 wild type strains with various degrees of potency. Wen2010 (neutralization)
4.8d: B cell depletion in an HIV-1 infected patient using rituximab led to a decline in NAb titers and rising viral load. Recovery of NAb titers resulted in control of viral load, and the newly emerged virus population was examined. Strong binding competition between patient sera and 4.8d was observed. Huang2010 (antibody interactions)
48d: To examine the antigenicity of a defined Ab epitope on the functional envelope spike, a panel of chimeric viruses engrafted at different positions with the hemagglutinin (HA) epitope tag was constructed. The neutralization sensitivity of all but one of the HA-tagged viruses to 48d was similar to the neutralization sensitivity of wild type virus to this Ab. One virus with HA-tag insertion in the V5 region was 10-fold more resistant to neutralization by 48d compared to the wild type. Pantophlet2009 (neutralization)
48d: NAb specificities of a panel of HIV sera were systematically analyzed by selective adsorption with native gp120 and specific mutant variants. To test for presence of coreceptor binding region MAbs in sera, gp120 I420 mutant was used. This mutant was not recognized by 48d. In some of the broadly neutralizing sera, the gp120-directed neutralization was mapped to CD4bs. Some sera were positive for NAbs against coreceptor binding region. A subset of sera also contained NAbs directed against MPER. Li2009c (assay or method development)
48d: The crystal structure for VRC01 in complex with an HIV-1 gp120 core from a clade A/E recombinant strain was analyzed to understand the structural basis for its neutralization breadth and potency. The number of mutations from the germline and the number of mutated contact residues for 48d were smaller than those for VRC01. Zhou2010 (neutralization, structure)
48D: Resurfaced stabilized core 3 (RSC3) protein was designed to preserve the antigenic structure of the gp120 CD4bs neutralizing surface but eliminate other antigenic regions of HIV-1. RSC3 did not show binding to 48D. Wu2010 (binding affinity)
48d: Binding of 48d to gp120 was not inhibited by YZ23, an Ab derived from mice immunized with eletcrophilic analogs of gp120 (E-gp120), indicating no overlap of these MAb epitopes. Nishiyama2009
48d: The Ig usage for variable heavy chain of this Ab was as follows: IGHV:1-f*01, IGHD:1-26, D-RF:2, IGHJ:3. Non-V3 mAbs preferentially used the VH1-69 gene segment. In contrast to V3 mAbs, these non-V3 mAbs used several VH4 gene segments and the D3-9 gene segment. Similarly to the V3 mAbs, the non-V3 mAbs used the VH3 gene family in a reduced manner. Anti-CD4i mAbs exclusively used the VH1 gene family. Gorny2009 (antibody sequence)
48d: Two different but genetically related viruses, CC101.19 and D1/85.16, which are resistant to small molecule CCR5 inhibitors, and two clones from their inhibitor sensitive parental strain CC1/85, were used to analyze interactions of HIV-1 with CCR5. CC101.19 had 4 substitutions in the V3 region and D1/85.16 had 3 changes in gp41. CC101.19 was neutralization sensitive to 48d, while this Ab had limited neutralization activity to the two parental clones and it did not neutralize D1/85.16. This indicates that at least one major element of the CCR5 binding site has become accessible in the inhibitor-resistant CC101.19 virus. Berro2009 (co-receptor, neutralization)
48d: 48d neutralized infection of PBLs with R5 HIV-1 strains with higher potency than X4 HIV-1 strains. However, 48d did not inhibit transcytosis of cell-free or cell-associated virus across a monolayer of epithelial cells. A mixture of 13 MAbs directed to well-defined epitopes of the HIV-1 envelope, including 48d, did not inhibit HIV-1 transcytosis, indicating that envelope epitopes involved in neutralization are not involved in mediating HIV-1 transcytosis. When the mixture of 13 MAbs and HIV-1 was incubated with polyclonal anti-human γ chain, the transcytosis was partially inhibited, indicating that agglutination of viral particles at the apical surface of cells may be critical for HIV transcytosis inhibition by HIV-specific Abs. Chomont2008 (neutralization)
48d: 48d structure, binding and neutralization activity, are reviewed in detail. Lin2007 (review)
4.8d: Transmission of HIV-1 by immature and mature DCs to CD4+ T lymphocytes was significantly higher for CXCR4- than for CCR5-tropic strains. However, preneutralization of X4 virus with 4.8d prior to capture efficiently blocked transmission to 75%, while transmission of R5 was blocked to 46%. vanMontfort2008 (co-receptor, neutralization, dendritic cells)
4.8d: Trimeric envelope glycoproteins with a partial deletion of the V2 loop derived from subtype B SF162 and subtype C TV1 were compared. The magnitude of 4.8d binding to subtype C trimer was lower than to subtype B trimer, either in the presence or absence of CD4. However, the fold increase in binding of 4.8d in presence of CD4 was similar for both subtypes, indicating similar structural rearrangements. Subtype C trimer had many biophysical, biochemical, and immunological characteristics similar to subtype B trimer, except for a difference in the three binding sites for CD4, which showed cooperativity of CD4 binding in subtype C but not in subtype B. Srivastava2008 (binding affinity, subtype comparisons)
48d: Contemporaneous biological clones of HIV-1 were isolated from plasma of chronically infected patients and tested for their functional properties. The clones showed striking functional diversity both within and among patients, including differences in infectivity and sensitivity to inhibition by 48d. There was no correlation between clonal virus infectivity and sensitivity to 48d inhibition, indicating that these properties are dissociable. The sensitivity to 48d inhibition was, however, a property shared by viruses from a given patient, suggesting that the genetic determinants that define this sensitivity may lie in regions that are not necessarily subject to extensive diversity. Nora2008 (neutralization)
48D: A new purification method was developed using a high affinity peptide mimicking CD4 as a ligand in affinity chromatography. This allowed the separation in one step of HIV envelope monomer from cell supernatant and capture of pre-purified trimer. Binding of 48D to gp120SF162 purified by the miniCD4 affinity chromatography and a multi-step method was comparable, suggesting that the miniCD4 allows the separation of HIV-1 envelope with intact 48D epitope. gp140DF162ΔV2 was purified by the miniCD4 method to assess its ability to capture gp140 trimers. Purified gp140DF162ΔV2 was recognized by 48D, and the k-off value for 48D was reduced compared to gp120SF162 monomer, consistent with the gp140DF162ΔV2 trimeric conformation. Binding of 48D to gp140DF162ΔV2 purified by the miniCD4 affinity chromatography and a multi-step method was comparable, suggesting that the SF162 trimer antigenicity was preserved. Martin2008 (assay or method development, kinetics, binding affinity)
4.8d: 4.8d-neutralized HIV-1 captured on Raji-DC-SIGN cells or immature monocyte-derived DCs (iMDDCs) was successfully transferred to CD4+ T lymphocytes, indicating that the 4.8d-HIV-1 complex was disassembled upon capture by DC-SIGN-cells. vanMontfort2007 (neutralization, dendritic cells)
48d: The structure of the V3 region in the context of gp120 core complexed to the CD4 receptor and to the 48d Ab was attempted to be determined by X-ray resolution, but only the structure for V3 complexed with CD4 and X5 Ab was solved. Huang2005 (structure)
48d: Point mutations in the highly conserved structural motif LLP-2 within the intracytoplasmic tail of gp41 resulted in conformational alternations of both gp41 and gp120. The alternations did not affect virus CD4 binding, coreceptor binding site exposure, or infectivity of the virus, but did result in decreased binding and neutralization by certain MAbs and human sera. 48d exhibited similar levels of binding to both the LLP-2 mutant and wildtype viruses, indicating that sCD4 binding to the LLP-2 mutant successfully triggered conformational change of gp120 and exposure of the co-receptor binding site. Kalia2005 (antibody binding site, binding affinity)
48D: Escape mutations in HR1 of gp41 that confer resistance to Enfuvirtide reduced infection and fusion efficiency and also delayed fusion kinetics of HIV-1. The mutations also conferred increased neutralization sensitivity of virus to 48D. Enhanced neutralization correlated with reduced fusion kinetics, indicating that the mutations result in Env proteins remaining in the CD4-triggered state for a longer period of time. Reeves2005 (antibody binding site, drug resistance, neutralization, escape, HAART, ART)
48D: This review summarizes data on the role of NAb in HIV-1 infection and the mechanisms of Ab protection, data on challenges and strategies to design better immunogens that may induce protective Ab responses, and data on structure and importance of MAb epitopes targeted for immune intervention. The importance of standardized assays and standardized virus panels in neutralization and vaccine studies is also discussed. Srivastava2005 (antibody binding site, neutralization, vaccine antigen design, review, structure)
48d: This Ab bound weakly to gp120IIIb and had no inhibitory effect on gp120 antigen presentation by MHC class II. 48d disassociated from gp120 at acidic pH. Lysosomal enzyme digestion of gp120 treated with 48d yielded fragmentation rate and pattern similar to that of gp120 alone. It is thus concluded that CD4i Ab 48d does not have an inhibitory effect on gp120 processing and presentation. Tuen2005 (antibody interactions, binding affinity)
48d: Ab neutralization of viruses with mixtures of neutralization-sensitive and neutralization-resistant envelope glycoproteins was measured. It was concluded that binding of a single Ab molecule is sufficient to inactivate function of an HIV-1 glycoprotein trimer. The inhibitory effect of the Ab was similar for neutralization-resistant and -sensitive viruses indicating that the major determinant of neutralization potency of an Ab is the efficiency with which it binds to the trimer. It was also indicated that each functional trimer on the virus surface supports HIV-1 entry independently, meaning that every trimer on the viral surface must be bound by an Ab for neutralization of the virus to be achieved. Yang2005b (neutralization)
48d: A substantial fraction of soluble envelope glycoprotein trimers contained inter-subunit disulfide bonds. Reduction of these disulfide bonds decreased binding of 48d to the glycoprotein, indicating that the inter-S-S bonds contribute to the exposure of the CD4-induced region. Yuan2005 (antibody binding site)
48d: This Ab was shown to infrequently neutralize cloned Envs (clades A, B, C, D, F1, CRF01_AE, CRF02_AG, CRF06_cpx and CRF11_cpx) derived from donors with and without broadly cross-reactive neutralizing antibodies. Cham2006 (neutralization, variant cross-reactivity, subtype comparisons)
4.8d: This Ab did not inhibit HIV-1 BaL replication in macrophages or in PHA-stimulated PBMCs. Holl2006 (neutralization, dendritic cells)
48d: 48d was used as a negative control to test CDR3 tyrosine sulfation of MAbs 47e, 412d, CM51 and E51, since it lacks CDR3 tyrosines. As expected, 48d did not incorporate sulfates while the other MAbs did. Neutralization assays showed that 48d was less efficient at neutralizing primary R5 and R5X4 isolates than MAbs 412d and E51, however, it was more efficient at neutralizing X4 isolates than these MAbs. Choe2003 (antibody binding site, neutralization)
48d: Antigens were designed to attempt to target immune responses toward the IgG1b12 epitope, while minimizing antibody responses to less desirable epitopes. One construct had a series of substitutions near the CD4 binding site (GDMR), the other had 7 additional glycans (mCHO). The 2 constructs did not elicit b12-like neutralizing antibodies, but both antigens successfully dampened other responses that were intended to be dampened while not obscuring b12 binding. CD4i MAbs (48d, 17b) did not bind to either GDMR or mCHO even with sCD4. Selvarajah2005 (vaccine antigen design, vaccine-induced immune responses)
48d: The HIV-1 Bori-15 variant was adapted from the Bori isolate for replication microglial cells. Bori-15 had increased replication in microglial cells and a robust syncytium-forming phenotype, ability to use low levels of CD4 for infection, and increased sensitivity to neutralization by sCD4 and 17b. Four amino acid changes in gp120 V1-V2 were responsible for this change. Protein functionality and integrity of soluble, monomeric gp120-molecules derived from parental HIV-1 Bori and microglia-adapted HIV-1 Bori-15 was assessed in ELISA binding assays using F105, IgG1b12, 17b and 48d, 2G12 and 447-52D. Association rates of sCD4 and 17b were not changed, but dissociation rates were 3-fold slower for sCD4 and 14-fold slower for 17b. Equilibrium binding studies showed 48d bound better to Bori-15 than Bori in the absence of sCD4, while 17b bound identically. Martin-Garcia2005 (antibody binding site)
48d: The epitope for the MAb D19 is conserved and embedded in V3. D19 is unique in that for R5 viruses, it was cryptic and did not bind without exposure to sCD4, and for X4 and R5X4 isolates it was constitutively exposed. D19b is unique among CD4i antibodies in that it binds to the V3 loop. CD4i MAbs 17b and 48d were used as controls for CD4i characterization; in contrast to D19, other CD4i MAbs bind to the conserved bridging sheet and do not differentiate between R5 and X4 using strains. Lusso2005
48d: By adding N-linked glycosylation sites to gp120, epitope masking of non-neutralizing epitopes can be achieved leaving the IgG1b12 binding site intact. This concept was originally tested with the addition of four glycosylation sites, but binding to b12 was reduced. It was modified here to exclude the C1 N-terminal region, and to include only three additional glycosylation sites. This modified protein retains full b12 binding affinity and it masks other potentially competing epitopes, and does not bind to 21 other MAbs to 7 epitopes on gp120, including 48d. Pantophlet2004 (vaccine antigen design)
48d: V1V2 was determined to be the region that conferred the neutralization phenotype differences between two R5-tropic primary HIV-1 isolates, JRFL and SF162. JRFL is resistant to neutralization by many sera and MAbs, while SF162 is sensitive. All MAbs tested, anti-V3, -V2, -CD4BS, and -CD4i, (except the broadly neutralizing MAbs IgG1b12, 2F5, and 2G12, which neutralized both strains), neutralized the SF162 pseudotype but not JRFL, and chimeras that exchanged the V1V2 loops transferred the neutralization phenotype. Three CD4i MAbs were tested; all preferentially neutralized SF162, and JRFL became neutralization sensitive to CD4i Abs if the SF162 V1V2 loop was exchanged. Pinter2004 (variant cross-reactivity)
48d: A set of HIV-1 chimeras that altered V3 net charge and glycosylation patterns in V1V2 and V3, involving inserting V1V2 loops from a late stage primary isolate taken after the R5 to X4 switch, were studied with regard to phenotype, co-receptor usage, and MAb neutralization. The loops were cloned into a HXB2 envelope with a LAI viral backbone. It was observed that the addition of the late-stage isolate V1V2 region and the loss of V3-linked glycosylation site in the context of high positive charge gave an X4 phenotype. R5X4, R5, and X4 viruses were generated, and sCD4, 2G12 and b12 neutralization resistance patterns were modified by addition of the late stage V1V2, glycosylation changes, and charge in concert, while neutralization by 2F5 was unaffected. 15e, 17b, and 48d could not neutralize any of the variants tested. Nabatov2004 (antibody binding site, co-receptor)
48d: Sera from two HIV+ people and a panel of MAbs were used to explore susceptibility to neutralization in the presence or absence of glycans within or adjacent to the V3 loop and within the C2, C4 and V5 regions of HIV-1 SF162 env gp120. The loss of the glycan within the V3 loop (GM299 V3) and two sites adjacent to V3, C2 (GM292 C2) and (GM329 C3), increased neutralization susceptibility to CD4i FAb X5, but each of the glycan mutants and SF162 were refractive to neutralization with 48d and 17b. The loss of sites in C4 (GM438 C4), or V5 (GM454 V5) did not increase neutralization susceptibility to FAb X5. V3 glycans tended to shield V3 loop, CD4 and co-receptor MAb binding sites, while C4 and V5 glycans shielded V3 loop, CD4, gp41 but not co-receptor MAb binding sites. Selective removal of glycans from a vaccine candidate may enable greater access to neutralization susceptible epitopes. McCaffrey2004 (antibody binding site, vaccine antigen design)
48d: Using a cell-fusion system, it was found CD4i antibodies 17b, 48d, and CG10 reacted faintly with Env expressing HeLA cells even in the absence of sCD4 or CD4 expressing target cells. Reactivity increased after sCD4 addition, but not after CD4 expressing target cell addition, and binding was not increased at the cell-to-cell CD4-Env interface. This suggests the CD4i co-receptor binding domain is largely blocked at the cell-fusion interface, and so CD4i antibodies would not be able access this site and neutralize cell-mediated viral entry. Finnegan2001 (antibody binding site)
48d: This review summarizes MAbs directed to HIV-1 Env. There are six CD4 inducible MAbs and Fabs in the database. The MAb forms neutralize TCLA strains only, but the smaller Fabs and scFv fragments can neutralize primary isolates. Gorny2003 (review)
48d: A gp120 molecule was designed to focus the immune response onto the IgG1b12 epitope. Ala substitutions that enhance the binding of IgG1b12 and reduce the binding of non-neutralizing MAbs were combined with additional N-linked glycosylation site sequons inhibiting binding of non-neutralizing MAbs; b12 bound to the mutated gp120. C1 and C5 were also removed, but this compromised b12 binding. Pantophlet2003b (vaccine antigen design)
48d: scFv 4KG5 reacts with a conformational epitope. Of a panel of MAbs tested, only NAb b12 enhanced 4KG5 binding to gp120. MAbs to the V2 loop, V3 loop, V3-C4 region, and CD4BS diminished binding, while MAbs directed against C1, CD4i, C5 regions didn't impact 4KG5 binding. These results suggest that the orientation or dynamics of the V1/V2 and V3 loops restricts CD4BS access on the envelope spike, and IgG1b12 can uniquely remain unaffected. This is a CD4i MAb that had no impact on 4KG5 binding. Zwick2003a (antibody interactions)
48d: Thermodynamics of binding to gp120 was measured using isothermal titration calorimetry for sCD4, 17b, b12, 48d, F105, 2G12 and C11 to intact YU2 and the HXBc2 core. The free energy of binding was similar. Enthalpy and entropy changes were divergent, but compensated. Not only CD4 but MAb ligands induced thermodynamic changes in gp120 that were independent of whether the core or the full gp120 protein was used. Non-neutralizing CD4BS and CD4i MAbs (17b, 48d, 1.5e, b6, F105 and F91) had large entropy contributions to free energy (mean: 26.1 kcal/mol) of binding to the gp120 monomer, but the potent CD4BS neutralizing MAb b6 had a much smaller value of 5.7 kcal/mol. The high values suggest surface burial or protein folding an ordering of amino acids. These results suggest that while the trimeric Env complex has four surfaces, a non-neutralizing face (occluded on the oligomer), a variable face, a neutralizing face and a silent face (protected by carbohydrate masking), gp120 monomers further protect receptor binding sites by conformational or entropic masking, requiring a large energy handicap for Ab binding not faced by other anti-gp120 Abs. Kwong2002 (antibody binding site)
48d: This study shows the fragments of CD4i MAbs are better able to neutralize virus than whole IgG. Neutralization of HIV-1 R5 isolates JRFL, JR-CSF and ADA by CD4i MAbs X5, 17b, and 48d decreased with increased molecule size, the neutralizing potency of single-chain Fv (scFv) > than Fab fragments > whole Ab molecules. (With the exception of IgG 48d neutralization of HIV-1 ADA being better than the Fab -- for 48d, only the IgG and Fab forms were available, not the scFv.) HIV-1 X4 isolates 89.6 and HxB2 are both relatively sensitive even to the larger IgG version. R5X4 isolate neutralization was dependent on the isolate and co-receptor usage. The CD4i MAb fragments neutralize HIV-1 subsequent to CD4 binding. The CD4i MAbs bind near the co-receptor binding sites on gp120. Co-receptors bind to the conserved beta19 strand and part of the V3 loop, regions that are masked by the V1V2 loops in the CD4-unbound state. When CD4 is bound, the co-receptor site is exposed near the membrane surface where it would be optimally accessible to co-receptors, and the smaller versions of the molecules are better able to overcome the steric hindrance. Labrijn2003 (antibody binding site, co-receptor, variant cross-reactivity)
48d: Called 4.8d. The MAb B4e8 binds to the base of the V3 loop, neutralizes multiple primary isolates and was studied for interaction with other MAbs. B4e8 enhanced binding of CD4i MAbs 4.8d, 1.7b, and A1g8 to R5X4 virus 92HT593, but only of 48d to the R5 virus 92US660, and there was only a modest impact of the combination of B4e8 and CD4i MAbs on neutralization. Cavacini2003 (antibody interactions, co-receptor)
48d: This study examined antibody interactions, binding and neutralization with a B clade R5 isolate (92US660) and R5X4 isolate (92HT593). Abs generally bound and neutralized the R5X4 isolate better than the R5 isolate. Anti-V3 MAb B4a1 increased binding of CD4i MAbs 48d, 17b and A1g8, but only A1g8 binding was increased by B4a1 to the R5 isolate. Additive effects on neutralization of the R5X4 isolate with B4a1 and CD4i MAbs was observed, presumably due to increased exposure of the CD4i binding site, but not for the R5 isolate. Anti-gp41 MAb F240 had a synergistic effect on neutralization with CD4i MAbs 48d and 17b, but not with A1g8 for the R5X4 virus. Cavacini2002 (variant cross-reactivity)
48d: NIH AIDS Research and Reference Reagent Program: 1756.
48d: Called 4.8D -- A rare mutation in the neutralization sensitive R2-strain in the proximal limb of the V3 region caused Env to become sensitive to neutralization by MAbs directed against the CD4 binding site (CD4BS), CD4-induced (CD4i) epitopes, soluble CD4 (sCD4), and HNS2, a broadly neutralizing sera -- 2/12 anti-V3 MAbs tested (19b and 694/98-D) neutralized R2, as did 2/3 anti-CD4BS MAbs (15e and IgG1b12), 2/2 CD4i MAbs (17b and 4.8D), and 2G12 and 2F5 -- thus multiple epitopes on R2 are functional targets for neutralization and the neutralization sensitivity profile of R2 is intermediate between the highly sensitive MN-TCLA strain and the typically resistant MN-primary strain. Zhang2002 (variant cross-reactivity)
48d: Truncation of the gp41 cytoplasmic domain of X4, R5, and X4R5 viruses forces a conformation that more closely resembles the CD4 bound state of the external Envelope, enhancing binding of CD4i MAbs 17b and 48d and of CD4BS MAbs F105, b12, and in most cases of glycosylation site dependent MAb 2G12 and the anti-gp41 MAb 246D -- in contrast, binding of the anti-V2 MAb 697D and the anti-V3 MAb 694/98D were not affected -- viruses bearing the truncation were more sensitive to neutralization by MAbs 48d, b12, and 2G12 -- the anti-C5 MAb 1331A was used to track levels of cell surface expression of the mutated proteins. EdwardsBH2002 (co-receptor)
48d: Five CD4i MAbs were studied, 17b, 48d and three new MAbs derived by Epstein-Barr virus transformation of PBMC from an HIV+ long term non-progressor -- 23e and 21c were converted to hybridomas to increase Ab production -- all compete with the well-characterized 17b CD4i MAb in an ELISA antigen capture assay -- critical binding residues are mapped and the CD4i MAb epitopes were distinct but share a common element near isoleucine 420, also important for CCR5 binding, and all five can block CCR5 binding to a sCD4-gp120 complex -- the MAb 48d has the epitope most similar to the CCR5 binding site. Xiang2002b (antibody binding site, co-receptor)
48d: A series of mutational changes were introduced into the YU2 gp120 that favored different conformations -- 375 S/W seems to favor a conformation of gp120 closer to the CD4-bound state, and is readily bound by sCD4 and CD4i MAbs (17b, 48d, 49e, 21c and 23e) but binding of anti-CD4BS MAbs (F105, 15e, IgG1b12, 21h and F91 was markedly reduced -- IgG1b12 failed to neutralize this mutant, while neutralization by 2G12 was enhanced -- 2F5 did not neutralize either WT or mutant, probably due to polymorphism in the YU2 epitope -- another mutant, 423 I/P, disrupted the gp120 bridging sheet, favored a different conformation and did not bind CD4, CCR5, or CD4i antibodies, but did bind to CD4BS MAbs. Xiang2002
48d: Uncleaved soluble gp140 (YU2 strain, R5 primary isolate) can be stabilized in an oligomer by fusion with a C-term trimeric GCN4 motif or using a T4 trimeric motif derived from T4 bacteriophage fibritin -- stabilized oligomer gp140 delta683(-FT) showed strong preferential recognition by NAbs IgG1b12 and 2G12 relative to the gp120 monomer, in contrast to poorly neutralizing MAbs F105, F91, 17b, 48d, and 39F which showed reduced levels of binding, and C11, A32, and 30D which did not bind the stabilized oligomer. Yang2002
48d: The fusion process was slowed by using a suboptimal temperature (31.5 C) to re-evaluate the potential of Abs targeting fusion intermediates to block HIV entry -- preincubation of E/T cells at 31.5 C enabled polyclonal anti-N-HR Ab and anti-six-helix bundle Abs to inhibit fusion, indicating six-helix bundles form prior to fusion -- the preincubation 31.5 C step did not alter the inhibitory activity of neutralizing Abs anti-gp41 2F5, or anti-gp120 2G12, IG1b12, 48d, and 17b. Database note: First author "GoldingH" is distinct from another author found as both "GoldingB" & "Golding" on annotated papers in this database. GoldingH2002
48d: Called 4.8d -- A panel of 12 MAbs was used to identify those that could neutralize the dual-tropic primary isolate HIV-1 89.6 -- six gave significant neutralization at 2 to 10 ug/ml: 2F5, 50-69, IgG1b12, 447-52D, 2G12, and 670-D six did not have neutralizing activity: 654-D, 4.8D, 450-D, 246-D, 98-6, and 1281 -- no synergy, only additive effects were seen for pairwise combinations of MAbs, and antagonism was noted between gp41 MAbs 50-69 and 98-6, as well as 98-6 and 2F5. Verrier2001
48d: Mutations in two glycosylation sites in the V2 region of HIV-1 ADA at positions 190 and 197 (187 DNTSYRLINCNTS 199) cause the virus to become CD4-independent and able to enter cells through CCR5 alone -- these same mutations tended to increase the neutralization sensitivity of the virus, including to 48d -- only the CD4i antibodies 17b and 48d showed an increased affinity of the CD4 independent viruses relative to wild-type. Kolchinsky2001
48d: A combination of gp41 fusion with the GNC4 trimeric sequences and disruption of the YU2 gp120-gp41 cleavage site resulted in stable gp140 trimers (gp140-GNC4) that preserve and expose some neutralizing epitopes while occluding some non-neutralizing epitopes -- CD4BS MAbs (F105 and F91) and CD4i (17b and 48d) recognized gp140-GNC4 as well as gp120 or gp140 -- non-neutralizing MAbs C11, A32, 522-149, M90, and #45 bound to the gp140-GNC4 glycoprotein at reduced levels compared to gp120 -- MAbs directed at the extreme termini of gp120 C1 (135/9 and 133/290) and C5 (CRA-1 and M91) bound efficiently to gp140-GNC4. Yang2000
48d: sCD4 can activate fusion between effector cells expressing Env and target cells expressing coreceptor (CCR5 or CXCR4) alone without CD4 -- CD4i MAbs 17b and 48d have little effect on a standard cell fusion assay but potently block sCD4 activated fusion. Salzwedel2000 (co-receptor)
48d: Six mutations in MN change the virus from a high-infectivity neutralization resistant phenotype to low-infectivity neutralization sensitive -- V3, CD4BS, and CD4i MAbs are 20-100 fold more efficient at neutralizing the sensitive form -- the mutation L544P reduced binding of all MAbs against gp120 by causing conformational changes. Park2000
48d: SF162 is a neutralization-resistant HIV-1 isolate -- N-linked glycosylation modifications in the V2 loop of the SF162 gp120 revealed that these sites prevent neutralization by CD4BS MAbs (IgG1b12 and IgGCD4), and protect against neutralization by V3 MAbs (447-D and 391-95D) -- V2-region glycosylation site mutations did not alter neutralization resistance to V2 MAbs (G3.4 and G3.136) or CD4i MAbs (17b and 48d) -- V2 glycosylation site modification allows infection of macrophages, probably due to glycosylated forms requiring fewer CCR5 molecules for viral entry. Ly2000
48d: Called 4.8D -- host encoded intercellular adhesion molecule (ICAM-1) is incorporated by the HIV-1 virion and enhances viral infectivity -- ICAM-1 does not modify virus sensitivity to antibodies 0.5beta or 4.8D or sCD4, but neutralizing ability of F105 was diminished in ICAM bearing virions in the presence of lymphocyte function-association antigen-1 (LFA-1) Ab. Fortin2000
48d: A CD4-independent viral variant of IIIB, IIIBx, was generated on CXCR4-expressing cells -- IIIBx exhibited greater exposure of the 17b and 48d epitopes and enhanced neutralization by CD4i MAbs and by polyclonal human sera. Hoffman1999
48d: Infection of dendritic cells cultured from CD14+ blood cells or from cadaveric human skin was blocked by neutralizing MAbs IgG1b12, or 2F5 and 2G12 delivered together, but not by control non-neutralizing anti-gp120 MAb 4.8D, indicating that NAbs could interrupt early mucosal transmission events. Frankel1998
48d: Deleting the V2 loop of neutralization-resistant HIV-1 isolate SF162 does not abrogate its replication in PBMC or macrophages, but it enhances its neutralization sensitivity to sera from patients with B clade infection up to 170-fold, and also enhances sensitivity to sera from clades A through F -- deletion of V2 but not V1 enabled neutralization by CD4i MAbs 17b and 48d. Stamatatos1998
48d: A panel of MAbs were shown to bind with similar or greater affinity and similar competition profiles to a deglycosylated or variable loop deleted core gp120 protein (Delta V1, V2, and V3), thus such a core protein produces a structure closely approximating full length folded monomer -- CD4i MAbs 17b and 48d bound better to the deleted protein than to wild type. Binley1998
48d: A neutralization assay was developed based on hemi-nested PCR amplification of the LTR (HNPCR) -- LTR-HNPCR consistently revealed HIV DNA and was shown to be a rapid, specific and reliable neutralization assay based on tests with 6 MAbs and 5 isolates. Yang1998
48d: CD4i MAbs 17b and 48d compete with MAb CG10, and the binding sites may overlap -- MAb A32 enhances binding of 17b, 48d and CG10. Sullivan1998
48d: The MAb and Fab binding to the oligomeric form of gp120 and neutralization were highly correlated -- authors suggest that neutralization is determined by the fraction of Ab sites occupied on a virion irrespective of the epitope. Parren1998
48d: Inhibits binding of Hx10 to both CD4 positive and CD4 negative HeLa cells. Mondor1998
48d: Summary of the implications of the crystal structure of the core of gp120 bound to CD4 and 17b with what is known about mutations that reduce NAb binding -- probable mechanism of neutralization of 48d is interference with chemokine receptor binding -- CD4 binding increases exposure of epitope due to V2 loop movement -- 88N, 117K, 121K, 256S, 257T, N262, delta V3, E370, E381, F 382, R 419, I 420, K 421, Q 422, I 423, W 427, Y 435, P 438, M 475 mutations in HXBc2 (IIIB) decrease binding. Wyatt1998 (structure)
48d: Neutralizes TCLA strains, but not primary isolates. Parren1997 (variant cross-reactivity)
48d: Binds efficiently to sgp120 but not soluble gp120+gp41, suggesting its gp120 epitope is blocked by gp41 binding. Wyatt1997 (antibody binding site)
48d: Viral binding inhibition by 48d was strongly correlated with neutralization (all other neutralizing MAbs tested showed some correlation except 2F5). Ugolini1997
48d: Prefers CD4-gp120 complex to gp120 alone, but does not enhance fusion, in contrast to MAb CG10, in fact it inhibits syncytium formation. Lee1997 (antibody binding site)
48d: 48d binds to the IIIB protein and not IIIB V3 peptide, while binding to the Can0A V3 peptide, suggesting Can0A V3 is a conformer that mimics the 48d, (but not 17b), epitope. Weinberg1997 (antibody binding site)
48d: One of 14 human MAbs tested for ability to neutralize a chimeric SHIV-vpu+, which expressed HIV-1 IIIB env -- all Ab combinations tested showed synergistic neutralization -- 48d has synergistic response with MAbs 694/98-D (anti-V3) and F105. Li1997 (antibody interactions)
48d: Neutralizes JR-FL -- slightly inhibits gp120 interaction with CCR-5 in a MIP-1beta-CCR-5 competition study. Trkola1996b (antibody binding site, co-receptor)
48d: Binding resulted in gp120 dissociation from virion, mimicking sCD4, and exposure of the gp41 epitope of MAb 50-69, in contrast to CD4BS MAbs. Poignard1996b (antibody interactions)
48d: Many MAbs inhibit binding (anti-C1, -C5, -C4, -CD4BS) -- anti-C1-C4 discontinuous epitope MAbs A32 and 2/11c enhance binding -- reciprocal enhanced binding with some anti-V2 MAbs. Moore1996 (antibody interactions)
48d: Binds with similar affinity to monomer and oligomer, moderate association rate, potent neutralization -- this is in contrast to 17b, which has very different kinetics. Sattentau1995a (antibody binding site, kinetics, binding affinity)
48d: Formalin inactivation of virus at 0.1% formalin for 10 hours at 4 degrees was optimal for inactivation of virus while maintaining epitope integrity. Sattentau1995 (vaccine antigen design)
48d: Studies using a V1/V2 deletion mutant demonstrated that enhanced binding of 48d in the presence of sCD4 involves the V1/V2 loops, with more significant involvement of V2 -- similar effect observed for 17b and A32. Wyatt1995 (vaccine antigen design)
48d: Called 4.8D -- Found to neutralize MN, but not JRCSF, two B subtype primary isolates, or a D subtype primary isolate, by most labs in a multi-laboratory study involving 11 labs. DSouza1995 (variant cross-reactivity, subtype comparisons)
48d: Poor cross-reactivity with gp120 from most clades. Moore1994b (subtype comparisons)
48d: A mutation in gp41, 582 A/T, confers resistance to neutralization (also confers resistance to MAbs F105, 21h, 15e and 17b). Thali1994 (variant cross-reactivity)
48d: Binding of 48d is much more influenced by sequence variation among molecular clones of LAI than is binding of 17b. Moore1993d (variant cross-reactivity)
48d: Called 4.8d -- Neutralizes IIIB -- reactive with SF-2 gp120 -- does not inhibit HIV-1 sera from binding to IIIB gp120. Moore1993a (variant cross-reactivity)
48d: Epitope is better exposed upon CD4 binding to gp120 -- competes with ICR 39.13, 15e and 21h, anti-CD4 binding site MAbs -- inhibited by anti-CD4BS MAb ICR 39.13g and linear anti-C4 MAbs G3-42 and G3-508 -- 113 D/R, 252 R/W, 257 T/A or G, 370 E/D, 382 F/L, 420 I/R, 421 K/L, 433A/L, 438 P/R and 475 M/S confer decreased sensitivity to neutralization. Thali1993 (antibody binding site, antibody interactions)
48d database comments: 48d and 17b have similar epitopes, and the pair are unique among human and rodent MAbs. Thali1993 mentions that 17b and 48d were derived from different patients, and cites the original generation of these antibodies to Robinson and Ho, unpublished data. 4.8D is a CHAVI reagent (http://chavi.org/); Species: human; Category: CD4i MAbs; Contact person: James Robinson

References

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DSouza1995 M. P. D'Souza, G. Milman, J. A. Bradac, D. McPhee, C. V. Hanson, and R. M. Hendry. Neutralization of Primary HIV-1 Isolates by Anti-Envelope Monoclonal Antibodies. AIDS, 9:867-874, 1995. Eleven labs tested the 6 human MAbs 1125H, TH9, 4.8D, 257-D-IV, TH1, 2F5, and also HIVIG for neutralization of MN, JRCSF, the two B clade primary isolates 301657 and THA/92/026, and the D clade isolate UG/92/21. 2F5 was the most broadly neutralizing, better than HIVIG. The other MAbs showed limited neutralization of only MN (anti-CD4BS MAbs 1125H, TH9, and 4.8D), or MN and JRCSF (anti-V3 MAbs 257-D-IV and TH1). PubMed ID: 7576320. Show all entries for this paper.

Fortin2000 J. F. Fortin, R. Cantin, M. G. Bergeron, and M. J. Tremblay. Interaction between Virion-Bound Host Intercellular Adhesion Molecule-1 and the High-Affinity State of Lymphocyte Function-Associated Antigen-1 on Target Cells Renders R5 and X4 Isolates of Human Immunodeficiency Virus Type 1 More Refractory to Neutralization. Virology, 268:493-503, 2000. PubMed ID: 10704357. Show all entries for this paper.

Frankel1998 S. S. Frankel, R. M. Steinman, N. L. Michael, S. R. Kim, N. Bhardwaj, M. Pope, M. K. Louder, P. K. Ehrenberg, P. W. Parren, D. R. Burton, H. Katinger, T. C. VanCott, M. L. Robb, D. L. Birx, and J. R. Mascola. Neutralizing Monoclonal Antibodies Block Human Immunodeficiency Virus Type 1 Infection of Dendritic Cells and Transmission to T Cells. J. Virol., 72:9788-9794, 1998. Investigation of three human MAbs to elicit a neutralizing effect and block HIV-1 infection in human dendritic cells. Preincubation with NAbs IgG1b12 or a combination of 2F5/2G12 prevented infection of purified DC and transmission in DC/T-cell cultures. PubMed ID: 9811714. Show all entries for this paper.

Huang2010 Kuan-Hsiang G. Huang, David Bonsall, Aris Katzourakis, Emma C. Thomson, Sarah J. Fidler, Janice Main, David Muir, Jonathan N. Weber, Alexander J. Frater, Rodney E. Phillips, Oliver G. Pybus, Philip J. R. Goulder, Myra O. McClure, Graham S. Cooke, and Paul Klenerman. B-Cell Depletion Reveals a Role for Antibodies in the Control of Chronic HIV-1 Infection. Nat. Commun., 1:102, 2010. PubMed ID: 20981030. Show all entries for this paper.

Klein2012 Florian Klein, Christian Gaebler, Hugo Mouquet, D. Noah Sather, Clara Lehmann, Johannes F. Scheid, Zane Kraft, Yan Liu, John Pietzsch, Arlene Hurley, Pascal Poignard, Ten Feizi, Lynn Morris, Bruce D. Walker, Gerd Fätkenheuer, Michael S. Seaman, Leonidas Stamatatos, and Michel C. Nussenzweig. Broad Neutralization by a Combination of Antibodies Recognizing the CD4 Binding Site and a New Conformational Epitope on the HIV-1 Envelope Protein. J. Exp. Med., 209(8):1469-1479, 30 Jul 2012. PubMed ID: 22826297. Show all entries for this paper.

Lee1997 S. Lee, K. Peden, D. S. Dimitrov, C. C. Broder, J. Manischewitz, G. Denisova, J. M. Gershoni, and H. Golding. Enhancement of Human Immunodeficiency Virus Type 1 Envelope-Mediated Fusion by a CD4-gp120 Complex-Specific Monoclonal Antibody. J. Virol., 71:6037-6043, 1997. PubMed ID: 9223495. Show all entries for this paper.

Mondor1998 I. Mondor, S. Ugolini, and Q. J. Sattentau. Human Immunodeficiency Virus Type 1 Attachment to HeLa CD4 Cells Is CD4 Independent and Gp120 Dependent and Requires Cell Surface Heparans. J. Virol., 72:3623-3634, 1998. PubMed ID: 9557643. Show all entries for this paper.

Moore1993a J. P. Moore and D. D. Ho. Antibodies to discontinuous or conformationally sensitive epitopes on the gp120 glycoprotein of human immunodeficiency virus type 1 are highly prevalent in sera of infected humans. J. Virol., 67:863-875, 1993. CD4BS antibodies are prevalent in HIV-1-positive sera, while neutralizing MAbs to C4, V2, and V3 and MAbs to linear epitopes are less common. Most linear epitope MAbs in human sera are directed against the V3 region, and cross-reactive MAbs tend to be directed against discontinuous epitopes. PubMed ID: 7678308. Show all entries for this paper.

Moore1994b J. P. Moore, F. E. McCutchan, S.-W. Poon, J. Mascola, J. Liu, Y. Cao, and D. D. Ho. Exploration of Antigenic Variation in gp120 from Clades A through F of Human Immunodeficiency Virus Type 1 by Using Monoclonal Antibodies. J. Virol., 68:8350-8364, 1994. Four of five anti-V3 MAbs were slightly cross-reactive within clade B, but not very reactive outside clade B. Two discontinuous CD4 binding site Mabs appear to be pan-reactive. Anti-V2 MAbs were only sporadically reactive inside and outside of clade B. PubMed ID: 7525988. Show all entries for this paper.

Nora2008 Tamara Nora, Francine Bouchonnet, Béatrice Labrosse, Charlotte Charpentier, Fabrizio Mammano, François Clavel, and Allan J. Hance. Functional Diversity of HIV-1 Envelope Proteins Expressed by Contemporaneous Plasma Viruses. Retrovirology, 5:23, 2008. PubMed ID: 18312646. Show all entries for this paper.

Parren1998 P. W. Parren, I. Mondor, D. Naniche, H. J. Ditzel, P. J. Klasse, D. R. Burton, and Q. J. Sattentau. Neutralization of human immunodeficiency virus type 1 by antibody to gp120 is determined primarily by occupancy of sites on the virion irrespective of epitope specificity. J. Virol., 72:3512-9, 1998. The authors propose that the occupancy of binding sites on HIV-1 virions is the major factor in determining neutralization, irrespective of epitope specificity. Neutralization was assayed T-cell-line-adapted HIV-1 isolates. Binding of Fabs to monomeric rgp120 was not correlated with binding to functional oligomeric gp120 or neutralization, while binding to functional oligomeric gp120 was highly correlated with neutralization. The ratios of oligomer binding/neutralization were similar for antibodies to different neutralization epitopes, with a few exceptions. PubMed ID: 9557629. Show all entries for this paper.

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Wen2010 Michael Wen, Reetakshi Arora, Huiqiang Wang, Lihong Liu, Jason T. Kimata, and Paul Zhou. GPI-Anchored Single Chain Fv---An Effective Way To Capture Transiently-Exposed Neutralization Epitopes on HIV-1 Envelope Spike. Retrovirology, 7:79, 2010. PubMed ID: 20923574. Show all entries for this paper.

Yang1998 G. Yang, M. P. D'Souza, and G. N. Vyas. Neutralizing Antibodies against HIV Determined by Amplification of Viral Long Terminal Repeat Sequences from Cells Infected In Vitro by Nonneutralized Virions. J. Acquir. Immune Defic. Syndr. Hum. Retrovirol., 17:27-34, 1998. A neutralization assay was developed based on heminested PCR amplification of the LTR (HNPCR) -- LTR-HNPCR consistently revealed HIV DNA and was shown to be a rapid, specific and reliable neutralization assay based on tests with 6 MAbs and 5 HIV isolates. PubMed ID: 9436755. Show all entries for this paper.

Displaying record number 1121

Download this epitope record as JSON.

MAb ID	X5 (Fab X5)
HXB2 Location	Env	Env Epitope Map
Author Location	gp120(gp120 JRFL)
Epitope
Subtype	B
Ab Type	gp120 CD4i
Neutralizing	P View neutralization details
Species (Isotype)	human
Patient	FDA2
Immunogen	HIV-1 infection
Keywords	ADCC, antibody binding site, antibody generation, antibody interactions, antibody lineage, antibody polyreactivity, antibody sequence, assay or method development, autoantibody or autoimmunity, binding affinity, chimeric antibody, co-receptor, escape, germline, glycosylation, immunotherapy, kinetics, mimics, neutralization, polyclonal antibodies, review, structure, subtype comparisons, vaccine antigen design, variant cross-reactivity

Notes

Showing 68 of 68 notes.

X5: Rabbits were immunized with a DNA vaccine encoding JR-CSF gp120. Five sera with potent autologous neutralizing activity were selected and compared with a human neutralizing plasma (Z23) and monoclonal antibodies targeting various regions of gp120 (VRC01, b12, b6, F425, 2F5, 2G12, and X5). The rabbit sera contained different neutralizing activities dependent on C3 and V5, C3 and V4, or V4 regions of the glycan-rich outer domain of gp120. All sera showed enhanced neutralizing activity toward an Env variant that lacked a glycosylation site in V4. The JR-CSF gp120 epitopes recognized by the sera were distinct from those of the mAbs. The activity of one serum required specific glycans that are also important for 2G12 neutralization, and this serum blocked the binding of 2G12 to gp120. The findings show that different fine specificities can achieve potent neutralization of HIV-1, yet this strong activity does not result in improved breadth. Narayan2013 (neutralization, polyclonal antibodies)
X5: The human Ab gene repertoires of uninfected and HIV-1-infected individuals were studied at genomic DNA (gDNA) and cDNA levels to determine the frequencies of putative germline Ab genes of known HIV-1 bnAbs. All libraries were deep sequenced and analysed using IMGT/HighV-QUEST software (http://imgt.org/HighV-QUEST/index. The human gDNA Ab libraries were more diverse in heavy and light chain V-gene lineage usage than the cDNA libraries. This implied that the human gDNA Ab gene repertoires may have more potential than the cDNA repertoires to develop HIV-1 bnmAbs. Relatively high frequencies of the VH and VKs and VLs that used the same V-genes and had the same CDR3 lengths as known HIV-1 bnmAbs regardless of (D)J-gene usage. The putative germline genes were determined for a set of mAbs (b12, VRC01, VRC03, NIH45-46, 3BNC60, PG9, PGT127, and X5). Zhang2013 (antibody lineage, germline)
X5: Chimeric antigen receptors, i.e., fusion proteins made from single-chain antibodies, may be a useful approach to immunotherapy. A set of mAbs were chosen based on their binding to a variety of sites on Env and availability of antibody sequences. The chimeric receptors were created by fusing the antibody's heavy chain, light chain, and two signaling domains into a single molecule. All 7 antibodies used to make the chimeric receptors (10E8, 3BNC117, PGT126, VRC01, X5, PGT128, PG9) showed specific killing of HIV-1 infected cells and suppression of viral replication against a panel of HIV-1 strains. Ali2016 (immunotherapy, chimeric antibody)
X5: This study assessed the ADCC activity of antibodies of varied binding types, including CD4bs (b6, b12, VRC01, PGV04, 3BNC117), V2 (PG9, PG16), V3 (PGT126, PGT121, 10-1074), oligomannose (2G12), MPER (2F5, 4E10, 10E8), CD4i (17b, X5), C1/C5 (A32, C11), cluster I (240D, F240), and cluster II (98-6, 126-7). ADCC activity was correlated with binding to Env on the surfaces of virus-infected cells. ADCC was correlated with neutralization, but not always for lab-adapted viruses such as HIV-1 NLA-3. MAb X5 had moderate ADCC activity against cells infected with 1 of 3 strains tested. vonBredow2016 (ADCC)
X5: A new trimeric immunogen, BG505 SOSIP.664 gp140, was developed that bound and activated most known neutralizing antibodies but generally did not bind antibodies lacking neuralizing activity. This highly stable immunogen mimics the Env spike of subtype A transmitted/founder (T/F) HIV-1 strain, BG505. Anti-CD4i non-NAb X5 did not neutralize BG505.T332N, the pseudoviral equivalent of the immunogen BG505 SOSIP.664 gp140, and did not recognize or bind the immunogen either. Sanders2013 (assay or method development, neutralization, binding affinity)
X5: X-ray crystallography, surface plasmon resonance and pseudovirus neutralization were used to characterize a heavy chain only llama antibody, named JM4. The full-length IgG2b version of JM4 neutralizes over 95% of circulating HIV-1 isolates. JM4 targets a hybrid epitope on gp120 that combines elements from both the CD4 binding region and the coreceptor binding surface. JM4 epitope overlaps with the CD4i binding site of X5. Acharya2013 (antibody binding site)
X5: This study uncovered a potentially significant contribution of V_H replacement products which are highly enriched in IgH genes for the generation of anti-HIV Abs including anti-gp41, anti-V3 loop, anti-gp120, CD4i and PGT Abs. The V_H replacement "footprints" within CD4i Abs preferentially encode negatively charged amino acids within IgH CDR3. The details of X5 V_H replacement products in IgH gene and mutations and amino acid sequence analysis are described in Table 1,Table 2 and Fig 3. Liao2013a (antibody sequence)
X5: Cryoelectron tomography was used to determine structures of A12, m36, or m36/CD4 complexed to trimeric Env displayed on intact HIV-1 BaL virus. The foot print of m36 binding on gp120 is near the base of the V3 loop which resembles a "fully open" conformation similar to Ab X5. Meyerson2013 (antibody binding site, structure)
X5: Somatic hypermutations are preferably found in CDR loops, which alter the Ab combining sites, but not the overall structure of the variable domain. FWR of CDR are usually resistant to and less tolerant of mutations. This study reports that most bnAbs require somatic mutations in the FWRs which provide flexibility, increasing Ab breadth and potency. To determine the consequence of FWR mutations the framework residues were reverted to the Ab's germline counterpart (FWR-GL) and binding and neutralizing properties were then evaluated. X5 was used in comparing the Ab framework amino acid replacement vs. interactive surface area on Ab. Klein2013 (neutralization, structure, antibody lineage)
X5: Small sized CD4 mimetics (miniCD4s) were engineered. These miniCD4s by themselves are poorly immunogenic and do not induce anti-CD4 antibodies. Stable covalent complexes between miniCD4s and gp120 and gp140 were generated through a site-directed coupling reaction. These complexes were recognized by CD4i antibodies as well as by the HIV co-receptor CCR5 and elicited CD4i antibody responses in rabbits. A panel of MAbs of defined epitope specificities, including MAb X5, was used to analyze the antigenic integrity of the covalent complexes using capture ELISA. Martin2011 (mimics, binding affinity)
X5: X5 MAb was used to study mechanism of neutralization by bnMAbs. In contrast to VRC01, PGV04 did not enhance 17b or X5 binding to their epitopes in the co-receptor region on the gp120 monomer, and in contrast to CD4, none of the CD4bs MAbs tested induced the 17b site on trimeric cleaved Env, suggesting that a degree of mimicry of CD4 by anti-CD4bs bnMAbs may be a consequence of binding to the CD4 epitope on monomeric gp120 rather than a neutralization mechanism. Falkowska2012 (neutralization)
X5: Broadly neutralizing HIV-1 immunity associated with VRC01-like antibodies was studied by isolation of VRC01-like neutralizers with CD4bs probe; structural definition of gp120 recognition by RSC3-identified antibodies from different donors; functional complementation of heavy and light chains among VRC01-like antibodies; identification of VRC01 antibodies by 454 pyrosequencing; and cross-donor phylogenetic analysis of sequences derived from the same precursor germline gene. X5 was studied among other antibodies that derive from a common IGHV1-69 allele to assess how atypical the VRC01-like antibody convergence was. T The angular difference in heavy-chain orientation between 17b, 412d, and X5 was over 90°, or roughly 10 times as much as among the VRC01-like antibodies. X5 had 49-67% sequence identity of its heavy and light chains to respective chains of VRC-PG04 and VRC-CH31. Wu2011 (structure)
X5: This review outlines the general structure of the gp160 viral envelope, the dynamics of viral entry, the evolution of humoral response, the mechanisms of viral escape and the characterization of broadly neutralizing Abs. X5 is noted in the review to be CD4i antibody and to have weak neutralizing activity against most HIV-1 isolates, with increased activity when soluble CD4 is added. Gonzalez2010 (neutralization, variant cross-reactivity, escape, review)
X5: Crystal structures of gp120 and gp41 in complex with CD4 and/or MAbs 17b, 48d, b12, b13, 412d, X5, 211C, C11, 15e, m6, m9 and F105 were used to determine the structure and the mobility of the gp41-interactive region of gp120. Elements determined to maintain the gp120-gp41 interaction were the gp120 termini and a newly described invariant 7-stranded β-sandwich. Structurally plastic elements of gp120 responsible for the various gp120 conformation changes due to receptor- or Ab-binding were structured into 3 layers, with the V1/V2 loops emanating from layer 2 and the highly glycosylated outer domain from layer 3. Pancera2010a (antibody binding site, structure)
X5: Unlike MAb m9, X5 did not compete with R5Nt for binding to gp120, indicating that the epitope for m9 differs from that of X5. Zhang2010 (antibody binding site)
X5: Molecular modeling was used to construct a 3D model of an anti-gp120 RNA aptamer, B40t77, in complex with gp120. The structure of the complex was compared to that of X5-gp120. Joubert2010 (structure)
X5: Unlike the MPER MAbs tested, X5 did not show any Env-independent virus capture in the conventional or in the modified version of the virus capture assay. There was an overall reduction in the efficiency of capture of molecular clones (MC) relative to pseudotyped virions (PSV) by X5, indicating that most of the surplus Env associated with PSV was in the form of unprocessed gp160. Nontrimeric Envs from JR-CSF MC virus were also captured by X5 more efficiently than trimeric Envs from JR-FL. Leaman2010
X5: 21c binding, autoreactivity, polyreactivity and protective benefits are discussed and compared to other autoreactive MAbs, such as 2F5 and 4E10. Regulation of CD4i MAbs, such as 21c and X5, by tolerance mechanisms is discussed. Haynes2010 (autoantibody or autoimmunity, antibody polyreactivity)
X5: A set of Env variants with deletions in V1/V2 was constructed. Replication competent Env variants with V1/V2 deletions were obtained using virus evolution of V1/V2 deleted variants. Sensitivity of the evolved ΔV1V2 viruses was evaluated to study accessibility of their neutralization epitopes. In the absence of sCD4, X5 did not bind well to the full-length trimers nor to the uncleaved ΔV1V2 trimers, but the binding was enhanced by addition of sCD4. X5 did not bind a ΔV1V2 virus carrying V120K substitution. Binding analyses of other CD4i Abs yielded slightly different results, indicating that various CD4i epitopes may be shielded to slightly different extents by the V1V2 domain. Bontjer2010 (antibody binding site, binding affinity)
X5: Neutralizing activities of X5 were similar against parent and GnTI (complex glycans of the neutralizing face are replaced by fully trimmed oligomannose stumps) viruses, and the N301Q mutant virus (glycan at position 301 is removed), with all viruses being resistant to neutralization by this Ab. X5 scFv complexed with sCD4 and Env trimers of parental and GnTI viruses. Binley2010 (glycosylation, neutralization)
X5: GPI-anchored and secretory scFvs of X5 were generated. GPI-scFvs were localized in the lipid raft of the plasma membrane. Cells transduced with the secretory X5 scFv showed low degree of neutralization against 3/11 tested pseudotype viruses belonging to clades A, B, B', C and E. GPI-anchored scFvs of X5 neutralized all 11 HIV-1 pseudotypes with great degree of potency. When tested against 6 wild type HIV-1 strains, secretory X5 scFv did not show any neutralization potency while X5 GPI-scFv neutralized all 6 strains with great degree of potency. sCD4 enhanced secretory X5 scFv neutralization potency but the X5 GPI-scFv neutralization was independent of sCD4 addition. In addition, GPI-scFv of X5 conferred long-term resistance to HIV-1 when expressed in human CD4+ T cells, it was shown to block HIV-1 envelope-mediated cell-cell fusion, and it blocked infection of HIV-1 captured and transferred by human DCs. Wen2010 (neutralization)
X5: The crystal structure for VRC01 in complex with an HIV-1 gp120 core from a clade A/E recombinant strain was analyzed to understand the structural basis for its neutralization breadth and potency. The number of mutations from the germline and the number of mutated contact residues for X5 were smaller than those for VRC01. Zhou2010 (neutralization, structure)
X5: Broadly neutralizing sera from elite neutralizers exhibited significant sensitivities to mutations I165A, N332A, and N160K. X5 binding and neutralization were tested for pseudoviruses with the mutations relative to the WT. X5 binding and neutralization were not affected by the these mutations. Unlike PG9 and PG16, X5 neutralized kifunensine-treated pseudoviruses with similar potency as wild type pseudoviruses. Walker2010 (neutralization, binding affinity)
X5: Ab gene divergence analyses found that X5 Ab was significantly more divergent from the closest germline Abs than were hmAbs against other viruses. Germline-like X5 was constructed in a scFv format. It was shown that, unlike b12, 2G12 and 2F5, germline-like X5 bound to recombinant gp140 with high affinity. Xiao2009 (binding affinity, antibody sequence)
X5: A review about the in vivo efficacy of MAbs against HIV-1, and about inhibition of HIV-1 infection by MAb fragments (Fab, scFv), including single molecules or fusion proteins of X5. Also, the efficacy of engineered human Ab variable domains or "domain antibodies" (dAbs) as therapeutic agents is reviewed. Chen2009b (neutralization, immunotherapy, review)
X5: The Ig usage for variable heavy chain of this Ab was as follows: IGHV:1-69*01, IGHD:3-22, D-RF:2, IGHJ:4. Non-V3 mAbs preferentially used the VH1-69 gene segment. In contrast to V3 mAbs, these non-V3 mAbs used several VH4 gene segments and the D3-9 gene segment. Similarly to the V3 mAbs, the non-V3 mAbs used the VH3 gene family in a reduced manner. Anti-CD4i mAbs exclusively used the VH1 gene family. Gorny2009 (antibody sequence)
X5: HIV-1 env sequence evolution was studied in 20 HIV-1 infected individuals undergoing treatment interruptions. By using the 3D structure of gp120 in complex with CD4 and X5, the amino acid residues that were found to be under positive selection mapped exclusively to the externally accessible residues of the gp120. There was no correlation between the number of positively selected amino acid sites and neutralizing Ab titers. Joos2007
X5: This review summarizes data on possible vaccine targets for elicitation of neutralizing Abs and discusses whether it is more practical to design a clade-specific than a clade-generic HIV-1 vaccine. Development of a neutralizing Ab response in HIV-1 infected individuals is reviewed, including data that show no apparent division of different HIV-1 subtypes into clade-related neutralization groups. Also, a summary of the neutralizing activity of MAb X5 in different HIV-1 clades is provided. McKnight2007 (variant cross-reactivity, review)
X5: This review provides information on the HIV-1 glycoprotein properties that make it challenging to target with neutralizing Abs. X5 neutralization properties and binding to HIV-1 envelope, and current strategies to develop versions of the Env spike with functional trimer properties for elicitation of broadly neutralizing Abs, are discussed. In addition, approaches to target cellular molecules, such as CD4, CCR5, CXCR4, and MHC molecules, with therapeutic Abs are reviewed. Phogat2007 (review)
X5: X5 structure, sulfation, binding, and neutralization activity are reviewed in detail. Improvement of potency and breadth of X5 neutralization is discussed. Vaccine strategies for elicitation of CD4i Abs are summarized. Lin2007 (review)
X5: This review summarizes X5 Ab epitope, properties and neutralization activity. The effect of differential CCR5 cell surface expression on X5 neutralization activity is discussed. Kramer2007 (co-receptor, neutralization, review)
X5: The various effects that neutralizing and non-neutralizing anti-envelope Abs have on HIV infection are reviewed, such as Ab-mediated complement activation and Fc-receptor mediated activities, that both can, through various mechanisms, increase and decrease the infectivity of the virus. The importance of these mechanisms in vaccine design is discussed. The unusual features of the X5 MAb are described. Willey2008 (review)
X5: Sera from both gp120 DNA prime-protein boost immunized rabbits and from protein-only immunized rabbits did not compete for binding to X5, indicating no elicitation of X5-like Abs by either of the immunization regimens. Vaine2008 (vaccine antigen design)
X5: This minireview summarizes data on differences in neutralizing activities of MAbs and pooled human sera using a traditional primary cell neutralization assay and the more standardized TZM-bl reporter cell line assay. Also, suggestions are made on how to improve and standardize neutralization assays for comparable use in different laboratories. It has previously been shown that X5 neutralizes considerably better in the PBMC assay, where the CD4/CCR5 ratio is approximately 10-fold larger than in the TZM-assay cells, underscoring the role of the cell substrate in neutralization assays. In total, however, the assay discordances were shown to be bi-directional and not attributable to assay sensitivity. Polonis2008 (assay or method development, neutralization, review)
X5: Immobilized X5 was able to capture infectious HIV-1 whole virions in a standard virus capture assay, unlike mAbs 8K8 and D5. Addition of soluble CD4 enhanced significantly virion capture by X5. Nelson2008
X5: The structure of a soluble CD4-FabX5-complexed gp120 core with the V3 loop attached was used to project the results of MAb mapping onto V3 in order to obtain better understanding of the spatial organization of residues identified as important for V3 MAb binding. Pantophlet2008 (structure)
X5: A new purification method was developed using a high affinity peptide mimicking CD4 as a ligand in affinity chromatography. This allowed the separation in one step of HIV envelope monomer from cell supernatant and capture of pre-purified trimer. Binding of X5 to gp120SF162 purified by the miniCD4 affinity chromatography and a multi-step method was comparable, suggesting that the miniCD4 allows the separation of HIV-1 envelope with intact X5 epitope. gp140DF162ΔV2 was purified by the miniCD4 method to assess its ability to capture gp140 trimers. Purified gp140DF162ΔV2 was recognized by X5, and the k-off value for X5 was reduced compared to gp120SF162 monomer, consistent with the gp140DF162ΔV2 trimeric conformation. Binding of X5 to gp140DF162ΔV2 purified by the miniCD4 affinity chromatography and a multi-step method was comparable, suggesting that the SF162 trimer antigenicity was preserved. Martin2008 (assay or method development, kinetics, binding affinity)
X5: Coordinates of the three-dimensional structure of trimeric Env displayed on native HIV-1 in complex with X5 were fitted on a density map, to reveal the structure of the trimeric glycoprotein spike on native HIV-1. Liu2008 (antibody binding site, structure)
X5: The study compared Ab neutralization against the JR-FL primary isolate and trimer binding affinities judged by native PAGE. There was direct quantitative relationship between monovalent Fab-trimer binding and neutralization, implying that neutralization begins as each trimer is occupied by one Ab. In BN-PAGE, neutralizing Fabs and sCD4 were able to shift JR-FL trimers. In contrast, most non-neutralizing Fabs, bound to monomer, but their epitopes were conformationally occluded on trimers, confirming the exclusive relationship of trimer binding and neutralization. Fab X5 did not bind effectively to gp120/gp41 monomers and may therefore recognize other forms of Env. Crooks2008 (neutralization, binding affinity)
X5: Macaques were immunized with either CD4, gp120, cross-linked gp120-human CD4 complex (gp120-CD4 XL), and with single chain complex containing gp120 rhesus macaque CD4 domains 1 and 2 (rhFLSC). Sera from the rhFLSC immunized animals showed highest competition titers, being able to block gp120-CD4 complex interactions with X5 more efficiently than sera from animals immunized with the three other proteins. DeVico2007 (neutralization)
X5: Guinea pigs were immunized with gp120 protein or with three types of VLPs containing disulfide-shackled functional trimers (SOS-VLP), uncleaved nonfunctional Env (UNC-VLP), naked VLP bearing no Env. Most of the Env-VLP sera and HIV-1+ plasma effectively blocked X5 capture. Crooks2007 (neutralization)
X5: Novel approaches based on sequential (SAP) and competitive (CAP) antigen panning methodologies, and use of antigens with increased exposure of conserved epitopes, for enhanced identification of broadly cross-reactive neutralizing Abs are reviewed. Abs identified by these methods are described. Zhang2007 (review)
X5: The structure of the X5 MAb, particularly its CDRH3 region tyrosine sulfation, is reviewed. Also, the mechanism of its binding to the coreceptor binding site of gp120, and comparisons of the neutralizing potencies of X5 Ab fragments vs the whole IgG molecule are discussed. Engineering of Abs based on revealed structures of broadly neutralizing MAbs is discussed. Burton2005 (antibody binding site, neutralization, review, structure)
X5: The structure of the V3 region in the context of gp120 core complexed to the CD4 receptor and to the X5 Ab was determined by X-ray resolution. Comparison of free and bound X5 structure showed a large structural difference for the third complementary loop of the X5 heavy chain, representing one of the largest induced fits observed for an antibody. Accessibility of co-receptor binding site to this MAb is shown in a 3D figure. Huang2005 (antibody binding site, structure)
X5: Used as a positive control in an HIVRP assay to confirm specificity of the inhibition of viral and cellular membrane fusion by the screened scFvs. Miller2005
X5: This review summarizes data on the role of NAb in HIV-1 infection and the mechanisms of Ab protection, data on challenges and strategies to design better immunogens that may induce protective Ab responses, and data on structure and importance of MAb epitopes targeted for immune intervention. The importance of standardized assays and standardized virus panels in neutralization and vaccine studies is also discussed. Srivastava2005 (antibody binding site, neutralization, vaccine antigen design, review)
X5: This review focuses on the importance of neutralizing Abs in protecting against HIV-1 infection, including mechanisms of Ab interference with the viral lifecycle, Ab responses elicited during natural HIV infection, and use of monoclonal and polyclonal Abs in passive immunization. In addition, vaccine design strategies for eliciting of protective broadly neutralizing Abs are discussed. MAbs included in this review are: 2F5, Clone 3 (CL3), 4E10, Z13, IgG1b12, 2G12, m14, 447-52D, 17b, X5, m16, 47e, 412d, E51, CM51, F105, F425, 19b, 2182, DO142-10, 697-D, 448D, 15e and Cβ1. McCann2005 (antibody binding site, neutralization, vaccine antigen design, review)
X5: X5 was investigated in different neutralization formats, including the standard format that measures activity over the entire infection period and several formats that emphasize various stages of infection. Significant activity of X5 was induced in the post-CD4 format while it did not neutralize JR-FL in the standard format. X5 did not have any activity in the post-CD4/CCR5 format. This suggests that the post-CD4, pre-CCR5 phase of infection is a narrow window of opportunity for neutralization of JR-FL by X5 Ab. Truncation of the gp160 cytoplasmic tail or addition of a disulfide bridge linking gp120 and gp41 did not increase X5 activity. Visualization of Env-Ab binding was conducted by BN-PAGE band shifts. Crooks2005 (antibody binding site, assay or method development, neutralization)
X5: This review summarizes data on 447-52D and 2219 crystallographic structures when bound to V3 peptides and their corresponding neutralization capabilities. X5, like 447-52D and like other HIV-1 neutralizing Abs, was shown to have long CDR H3 loop, which is suggested to help Abs access recessed binding sites on the virus. Stanfield2005 (antibody binding site, review, structure)
X5: In addition to gp120-gp41 trimers, HIV-1 particles were shown to bear nonfunctional gp120-gp41 monomers and gp120-depleted gp41 stumps on their surface. X5 did not neutralize wildype virus particles and it did not bind to functional gp12-gp41 trimers. It did, however, partially react with SOS, a mutant containing a disulfide bond between gp120 and gp41. X5 is able to recognize gp120-gp41 monomers and monomeric gp120. It is hypothesized that the nonfunctional monomers on the HIV-1 surface serve to divert the Ab response, helping the virus to avoid neutralization. Moore2006 (antibody binding site, neutralization)
X5: Macaques were immunized with SF162gp140, ΔV2gp140, ΔV2ΔV3gp140 and ΔV3gp140 constructs and their antibody responses were compared to the broadly reactive NAb responses in a macaque infected with SHIV SF162P4, and with pooled sera from humans infected with heterologous HIV-1 isolates (HIVIG). X5-like Abs were elicited at low titers by ΔV3gp140 but not by the other immunogens. They were also present in the SHIV-infected macaque. Derby2006 (antibody binding site)
X5: Virus was not neutralized by X5 in a standard neutralization assay, while pre-incubation of virus with sCD4 resulted in neutralization by X5 as its epitope was exposed upon binding to CD4. Binley2006 (antibody binding site, neutralization, binding affinity)
X5: Cloned Envs (clades A, B, C, D, F1, CRF01_AE, CRF02_AG, CRF06_cpx and CRF11_cpx) derived from donors either with or without broadly cross-reactive neutralizing antibodies were shown to be of comparable susceptibility to neutralization by X5. Cham2006 (neutralization, variant cross-reactivity, subtype comparisons)
X5: Neutralization of HIV-1 primary isolates from different clades (B, C, D and E) by X5 was determined in cells expressing high or low surface concentrations of CD4 and CCR5 receptors. CD4 cell surface concentration had no effect on the inhibitory activity of this Ab while the CCR5 surface concentration had a significant effect decreasing the 50% inhibitory concentration of X5 in cell lines with low CCR5. Choudhry2006 (co-receptor, neutralization, variant cross-reactivity, subtype comparisons)
X5: A direct comparison of phage and yeast display libraries was undertaken, and yeast display sampled the immune repertoire more fully. Previous results from panning a phage library generated from a long-term non-progressor were compared directly with a yeast library. As determined by sequencing, many MAbs were common to both, although the yeast library identifies unique scFv. X5 was identified using both methods. Bowley2007 (assay or method development, binding affinity, antibody sequence)
X5: By adding N-linked glycosylation sites to gp120, epitope masking of non-neutralizing epitopes can be achieved leaving the IgG1b12 binding site intact. This concept was originally tested with the addition of four glycosylation sites, but binding to b12 was reduced. It was modified here to exclude the C1 N-terminal region, and to include only three additional glycosylation sites. This modified protein retains full b12 binding affinity and it masks other potentially competing epitopes, and does not bind to 21 other MAbs to 7 epitopes on gp120, including X5. Pantophlet2004 (vaccine antigen design)
X5: 93 viruses from different clades were tested for their neutralization cross-reactivity using a panel of HIV antibodies. X5 is a CD4i antibody and neutralized only the most sensitive B-clade envelopes in the pseudovirus assay, but was able to neutralize 2/25 non-B isolates in the PBMC assay, possibly due to differential coreceptor expression. Binley2004 (variant cross-reactivity, subtype comparisons)
X5: V1V2 was determined to be the region that conferred the neutralization phenotype differences between two R5-tropic primary HIV-1 isolates, JRFL and SF162. JRFL is resistant to neutralization by many sera and MAbs, while SF162 is sensitive. All MAbs tested, anti-V3, -V2, -CD4BS, and -CD4i, (except the broadly neutralizing MAbs IgG1b12, 2F5, and 2G12, which neutralized both strains), neutralized the SF162 pseudotype but not JRFL, and chimeras that exchanged the V1V2 loops transferred the neutralization phenotype. Three CD4i MAbs were tested; all preferentially neutralized SF162, and JRFL became neutralization sensitive to CD4i Abs if the SF162 V1V2 loop was exchanged. FAb X5 could neutralize both viruses, but had reduced potency against JRFL. Pinter2004 (variant cross-reactivity)
X5: Sera from two HIV+ people and a panel of MAbs were used to explore susceptibility to neutralization in the presence or absence of glycans within or adjacent to the V3 loop and within the C2, C4 and V5 regions of HIV-1 SF162 env gp120. The loss of the glycan within the V3 loop (GM299 V3) and two sites adjacent to V3, C2 (GM292 C2) and (GM329 C3), increased neutralization susceptibility to CD4i FAb X5, but each of the glycan mutants and SF162 were refractive to neutralization with 48d and 17b. The loss of sites in C4 (GM438 C4), or V5 (GM454 V5) did not increase neutralization susceptibility to FAb X5. V3 glycans tended to shield V3 loop, CD4 and co-receptor MAb binding sites, while C4 and V5 glycans shielded V3 loop, CD4, gp41 but not co-receptor MAb binding sites. Selective removal of glycans from a vaccine candidate may enable greater access to neutralization susceptible epitopes. McCaffrey2004 (antibody binding site, vaccine antigen design)
X5: The structure of the Fab X5 was determined at 1.9 angstrom resolution. The binding site is a long, 22 amino acid CDR H3 with a hook shape. Long CDR H3s are also found in IgG1b12 (18 residues) and 17b (19 residues). FAb X5 has a W100, F100Y in the CDR H3 hook shown to be important for binding through site specific mutagenesis. Compared to JRCSF, Ala substitutions at eight residues reduced binding more than 3 fold: C119, K207, G367, M426, W427, V430, I423, and K432. Only I423A and K432A were thought to possibly directly interact with X5, the other mutations were thought likely to disrupt the overall structure or CD4 binding. Darbha2004 (antibody binding site, structure)
X5: This review summarizes MAbs directed to HIV-1 Env. There are six CD4 inducible MAbs and Fabs in the database. The MAb forms neutralize TCLA strains only, but the smaller Fabs and scFv fragments can neutralize primary isolates. Gorny2003 (review)
X5: A gp120 molecule was designed to focus the immune response onto the IgG1b12 epitope. Ala substitutions that enhance the binding of IgG1b12 and reduce the binding of non-neutralizing MAbs were combined with additional N-linked glycosylation site sequons inhibiting binding of non-neutralizing MAbs; b12 bound to the mutated gp120. C1 and C5 were also removed, but this compromised b12 binding. Pantophlet2003b (vaccine antigen design)
X5: scFv 4KG5 reacts with a conformational epitope. Of a panel of MAbs tested, only NAb b12 enhanced 4KG5 binding to gp120. MAbs to the V2 loop, V3 loop, V3-C4 region, and CD4BS diminished binding, while MAbs directed against C1, CD4i, C5 regions didn't impact 4KG5 binding. These results suggest that the orientation or dynamics of the V1/V2 and V3 loops restricts CD4BS access on the envelope spike, and IgG1b12 can uniquely remain unaffected. This is a CD4i MAb that had no impact on 4KG5 binding. Zwick2003a (antibody interactions)
X5: The Fab m18 was selected from a human phage display library by a new method called sequential antigen panning (SAP), using a series of antigens to screen the library to pick broadly cross-reactive isolates. The ability to block cell mediated fusion by m18 was compared to Fabs X5 and b12 for a clade A, CRF01 EA, G, and 6 clade B isolates, and the inhibitory activity of m18 was slightly lower but comparable to neutralizing Fabs b12 and X5. It also showed broad cross-neutralization; 11/15 pseudotyped Envs from primary isolates from clades A-F were inhibited in an IC50 assay at concentration less than or equal to 100 ug/ml; X5 was also tested and somewhat more potent, generally requiring lower concentrations and inhibiting 13/15 primary isolates. Zhang2003 (variant cross-reactivity, subtype comparisons)
X5: This study shows the fragments of CD4i MAbs are better able to neutralize virus than whole IgG. Neutralization of HIV-1 R5 isolates JRFL, JR-CSF and ADA by CD4i MAbs X5, 17b, and 48d decreased with increased molecule size, the neutralizing potency of single-chain Fv (scFv) > than Fab fragments > whole Ab molecules. (With the exception of IgG 48d neutralization of HIV-1 ADA.) HIV-1 X4 isolates 89.6 and HxB2 are both relatively sensitive even to the larger IgG version. R5X4 isolate neutralization was dependent on the isolate and co-receptor usage. The CD4i MAb fragments neutralize HIV-1 subsequent to CD4 binding. The CD4i MAbs bind near the co-receptor binding sites on gp120. Co-receptors bind to the conserved beta19 strand and part of the V3 loop, regions that are masked by the V1V2 loops in the CD4-unbound state. When CD4 is bound, the co-receptor site is exposed near the membrane surface where it would be optimally accessible to co-receptors, and the smaller versions of the molecules are better able to overcome the steric hindrance. Labrijn2003 (antibody binding site, co-receptor, variant cross-reactivity)
X5: Called Fab X5. This paper is a study of the 2F5 NAb complexed to peptide ELDKWAS; the peptide was found to interact with amino acids near the base of the very long (22 residue) CDR 3H region of the Ab, although a Phe at the apex of the loop was also important. The authors suggest that particularly long CDR H3 regions may be a common feature of HIV-1 neutralizing antibodies -- there are 22 residues in 2F5's H3, 18 in b12's H3, and 22 residues in X5's H3. They express concern that because small animals like mice are unable to elicit Ab responses with such long H3s, they may be poor model systems for HIV vaccine studies. Zwick2004a (antibody interactions)
X5: The SOS mutant envelope protein introduces a covalent disulfide bond between gp120 surface and gp41 transmembrane proteins into the R5 isolate JR-FL by adding cysteines at residues 501 and 605. Pseudovirions bearing this protein bind to CD4 and co-receptor bearing cells, but do not fuse until treatment with a reducing agent, and are arrested prior to fusion after CD4 and co-receptor engagement. CD4i Abs X5 and 17b were weakly neutralizing in all formats, WT, SOS, and when added postbinding. Binley2003 (vaccine antigen design)
X5: The human Fab X5 was selected from a phage display library derived from an HIV-1 positive donor with a highly neutralizing serum -- it was selected for binding to purified gp120-CD4-coreceptor complexes -- the Fab neutralizes PBMC infection by a selection of HIV-1 primary isolates from clades A, B, C, D, E, F, and G, and neutralizes R5, X4, and R5X4 isolates -- it binds to a conserved epitope on gp120 induced by CD4 binding, its binding is slightly enhanced by CCR5 binding -- while CD4i MAb 17b binds the CCR5 binding site, X5 also competes with Fab b12 which overlaps with the CD4 binding site, suggesting the epitope for is near both the CD4 and CCR5 binding sites. Moulard2002 (antibody binding site, antibody generation, variant cross-reactivity, subtype comparisons)

References

Showing 68 of 68 references.

Isolation Paper
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Binley2004 James M. Binley, Terri Wrin, Bette Korber, Michael B. Zwick, Meng Wang, Colombe Chappey, Gabriela Stiegler, Renate Kunert, Susan Zolla-Pazner, Hermann Katinger, Christos J. Petropoulos, and Dennis R. Burton. Comprehensive Cross-Clade Neutralization Analysis of a Panel of Anti-Human Immunodeficiency Virus Type 1 Monoclonal Antibodies. J. Virol., 78(23):13232-13252, Dec 2004. PubMed ID: 15542675. Show all entries for this paper.

Bowley2007 D. R. Bowley, A. F. Labrijn, M. B. Zwick, and D. R. Burton. Antigen Selection from an HIV-1 Immune Antibody Library Displayed on Yeast Yields Many Novel Antibodies Compared to Selection from the Same Library Displayed on Phage. Protein Eng. Des. Sel., 20(2):81-90, Feb 2007. PubMed ID: 17242026. Show all entries for this paper.

Crooks2005 Emma T. Crooks, Penny L. Moore, Douglas Richman, James Robinson, Jeffrey A. Crooks, Michael Franti, Norbert Schülke, and James M. Binley. Characterizing Anti-HIV Monoclonal Antibodies and Immune Sera by Defining the Mechanism of Neutralization. Hum Antibodies, 14(3-4):101-113, 2005. PubMed ID: 16720980. Show all entries for this paper.

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Crooks2008 Emma T. Crooks, Pengfei Jiang, Michael Franti, Sharon Wong, Michael B. Zwick, James A. Hoxie, James E. Robinson, Penny L. Moore, and James M. Binley. Relationship of HIV-1 and SIV Envelope Glycoprotein Trimer Occupation and Neutralization. Virology, 377(2):364-378, 1 Aug 2008. PubMed ID: 18539308. Show all entries for this paper.

Darbha2004 Ramalakshmi Darbha, Sanjay Phogat, Aran F. Labrijn, Yuuei Shu, Yijun Gu, Michelle Andrykovitch, Mei-Yun Zhang, Ralph Pantophlet, Loic Martin, Claudio Vita, Dennis R. Burton, Dimiter S. Dimitrov, and Xinhua Ji. Crystal Structure of the Broadly Cross-Reactive HIV-1-Neutralizing Fab X5 and Fine Mapping of Its Epitope. Biochemistry, 43(6):1410-1417, 17 Feb 2004. PubMed ID: 14769016. Show all entries for this paper.

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Moore2006 Penny L. Moore, Emma T. Crooks, Lauren Porter, Ping Zhu, Charmagne S. Cayanan, Henry Grise, Paul Corcoran, Michael B. Zwick, Michael Franti, Lynn Morris, Kenneth H. Roux, Dennis R. Burton, and James M. Binley. Nature of Nonfunctional Envelope Proteins on the Surface of Human Immunodeficiency Virus Type 1. J. Virol., 80(5):2515-2528, Mar 2006. PubMed ID: 16474158. Show all entries for this paper.

Narayan2013 Kristin M. Narayan, Nitish Agrawal, Sean X. Du, Janelle E. Muranaka, Katherine Bauer, Daniel P. Leaman, Pham Phung, Kay Limoli, Helen Chen, Rebecca I. Boenig, Terri Wrin, Michael B. Zwick, and Robert G. Whalen. Prime-boost immunization of rabbits with HIV-1 gp120 elicits potent neutralization activity against a primary viral isolate. PLoS One, 8(1):e52732 doi, 2013. PubMed ID: 23326351 Show all entries for this paper.

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Zhang2003 Mei-Yun Zhang, Yuuei Shu, Sanjay Phogat, Xiaodong Xiao, Fatim Cham, Peter Bouma, Anil Choudhary, Yan-Ru Feng, Inaki Sanz, Susanna Rybak, Christopher C. Broder, Gerald V. Quinnan, Thomas Evans, and Dimiter S. Dimitrov. Broadly Cross-Reactive HIV Neutralizing Human Monoclonal Antibody Fab Selected by Sequential Antigen Panning of a Phage Display Library. J. Immunol. Methods, 283(1-2):17-25, Dec 2003. PubMed ID: 14659896. Show all entries for this paper.

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Zwick2004a Michael B. Zwick, H. Kiyomi Komori, Robyn L. Stanfield, Sarah Church, Meng Wang, Paul W. H. I. Parren, Renate Kunert, Hermann Katinger, Ian A. Wilson, and Dennis R. Burton. The Long Third Complementarity-Determining Region of the Heavy Chain is Important in the Activity of the Broadly Neutralizing Anti-Human Immunodeficiency Virus Type 1 Antibody 2F5. J. Virol., 78(6):3155-3161, Mar 2004. PubMed ID: 14990736. Show all entries for this paper.

Displaying record number 1582

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MAb ID	412d (412D, 4.12D)
HXB2 Location	Env	Env Epitope Map
Author Location	gp120
Epitope
Subtype	B
Ab Type	gp120 CD4i, gp120 CCR5BS
Neutralizing
Contacts and Features	View contacts and features
Species (Isotype)	human
Patient	AC-01
Immunogen	HIV-1 infection
Keywords	ADCC, antibody binding site, antibody interactions, antibody lineage, antibody polyreactivity, antibody sequence, assay or method development, autoantibody or autoimmunity, binding affinity, co-receptor, kinetics, neutralization, review, structure, subtype comparisons, vaccine antigen design, variant cross-reactivity

Notes

Showing 35 of 35 notes.

412d: The first cryo-EM structure of a cross-linked vaccine antigen was solved. The 4.2 Å structure of HIV-1 BG505 SOSIP soluble recombinant Env in complex with a bNAb PGV04 Fab fragment revealed how cross-linking affects key properties of the trimer. SOSIP and GLA-SOSIP trimers were compared for antigenicity by ELISA, using a large panel of mAbs previously determined to react with BG505 Env. Non-NAbs like 412d globally lost reactivity (7-fold median loss of binding), likely because of covalent stabilization of the cross-linked ‘closed’ form of the GLA-SOSIP trimer that binds non-NAbs weakly or not at all. V3-specific non-NAbs showed 2.1–3.3-fold reduced binding. Three autologous rabbit monoclonal NAbs to the N241/N289 ‘glycan-hole’ surface, showed a median ˜1.5-fold reduction in binding. V3 non-NAb 4025 showed residual binding to the GLA-SOSIP trimer. By contrast, bNAbs broadly retained reactivity significantly better than non-NAbs, with exception of PGT145 (3.3-5.3 fold loss of binding in ELISA and SPR). Schiffner2018 (vaccine antigen design, binding affinity, structure)
412d: Env from of a highly neutralization-resistant isolate, CH120.6, was shown to be very stable and conformationally-homogeneous. Its gp140 trimer retains many antigenic properties of the intact Env, while its monomeric gp120 exposes more epitopes. Thus trimer organization and stability are important determinants for occluding epitopes and conferring resistance to antibodies. Among a panel of 21 mAbs, CH120.6 was resistant to neutralization by all non-neutralizing and strain-specific mAbs (including 412D), regardless of the location of their epitopes. It was weakly neutralized by several broadly-neutralizing mAbs (VRC01, NIH45-46, 12A12, PG9, PG16, PGT128, 4E10, and 10E8), and well neutralized by only 2 (PGT145 and 10-1074). Cai2017 (neutralization)
412d: In neutralization assays of antibody mixtures, there was a modest synergy between the CD4bs VRC01 and either of the two CD4i MAbs E51 and 412d. The synergy is likely the result of the ability of CD4i antibodies (E51 or 412d) to induce the open state and facilitate access to the CD4 binding site. The presence of E51 enhanced the Env binding of VRC01, NIH45-46, NIH45-46^G54W, and to a lesser extent 3BNC117. Gardner2016 (antibody interactions)
412d: Two stable homogenous gp140 Env trimer spikes, Clade A 92UG037.8 Env and Clade C C97ZA012 Env, were identified. 293T cells stably transfected with either presented fully functional surface timers, 50% of which were uncleaved. A panel of neutralizing and non-neutralizing Abs were tested for binding to the trimers. Non-neutralizing CD4i Ab, 412d did not bind cell surface or neutralize 92UG037.8 HIV-1 isolate, but it did bind well in the presence of sCD4. Chen2015 (neutralization, binding affinity)
412d: Env trimer BG505 SOSIP.664 as well as the clade B trimer B41 SOSIP.664 were stabilized using a bifunctional aldehyde (glutaraldehye, GLA) or a heterobifunctional cross-linker, EDC/NHS with modest effects on antigenicity and barely any on biochemistry or structural morphology. ELISA, DSC and SPR were used to test recognition of the trimers by bNAbs, which was preserved and by weakly NAbs or non-NAbs, which was reduced. Cross-linking partially preserves quaternary morphology so that affinity chromatography by positive selection using quaternary epitope-specific bNAabs, and negative selection using non-NAbs, enriched antigenic characteristics of the trimers. Binding of CD4i-epitope-recognizing non-NAb, 412D, to trimers was almost completely eliminated by trimer cross-linking. Schiffner2016 (assay or method development, binding affinity, structure)
412d: A new trimeric immunogen, BG505 SOSIP.664 gp140, was developed that bound and activated most known neutralizing antibodies but generally did not bind antibodies lacking neuralizing activity. This highly stable immunogen mimics the Env spike of subtype A transmitted/founder (T/F) HIV-1 strain, BG505. Anti-CD4i non-NAb 412d did not neutralize BG505.T332N, the pseudoviral equivalent of the immunogen BG505 SOSIP.664 gp140, and did not recognize or bind the immunogen either. Sanders2013 (assay or method development, neutralization, binding affinity)
412d: A highly conserved mechanism of exposure of ADCC epitopes on Env is reported, showing that binding of Env and CD4 within the same HIV-1 infected cell effectively exposes these epitopes. The mechanism might explain the evolutionary advantage of downregulation of cell surface CD4v by the Vpu and Nef proteins. 412d was used in co-expression assay to understand the conformational changes in Env upon CD4 binding. Veillette2014 (ADCC)
412d: The conserved central region of gp120 V2 contains sulfated tyrosines (Tys173 and Tys177) that in the CD4-unbound prefusion state mediate intramolecular interaction between V2 and the conserved base of the third variable loop (V3), functionally mimicking sulfated tyrosines in CCR5 and anti-coreceptor-binding-site antibodies such as 412d. Enhancement of tyrosine sulfation decreased binding and neutralization of HIV-1 BaL by monomeric sCD4, 412d, and anti-V3 antibodies and increased recognition by the trimer-preferring antibodies PG9, PG16, CH01, and PGT145. Conversely, inhibition of tyrosine sulfation increased sensitivity to soluble CD4, 412d, and anti-V3 antibodies and diminished recognition by trimer-preferring antibodies. These results identify the sulfotyrosine-mediated V2-V3 interaction as a critical constraint that stabilizes the native HIV-1 envelope trimer and modulates its sensitivity to neutralization. Cimbro2014
412d:X-ray crystallography, surface plasmon resonance and pseudovirus neutralization were used to characterize a heavy chain only llama antibody, named JM4. The full-length IgG2b version of JM4 neutralizes over 95% of circulating HIV-1 isolates. JM4 targets a hybrid epitope on gp120 that combines elements from both the CD4 binding region and the coreceptor binding surface. JM4 epitope overlaps with the CD4i binding site of 412d. Acharya2013 (neutralization)
Database comments: This antibody is not the same as 412-D, described in another entry. Choe2003 is the first publication to mention this monoclonal antibody. The patient was described by Montefiori2001. 4.12D is a CHAVI reagent (http://chavi.org/); Species: human; Category: CD4i MAbs; Contact person: James Robinson
412d: Isolation of VRC06 and VRC06b MAbs from a slow progressor donor 45 is reported. This is the same donor from whom bnMAbs VRC01, VRC03 and NIH 45-46 were isolated and the new MAbs are clonal variants of VRC03. 412d was used as a CoRB-specific MAb to compare binding specificity of VRC06. Li2012
412d: Somatic hypermutations are preferably found in CDR loops, which alter the Ab combining sites, but not the overall structure of the variable domain. FWR of CDR are usually resistant to and less tolerant of mutations. This study reports that most bnAbs require somatic mutations in the FWRs which provide flexibility, increasing Ab breadth and potency. To determine the consequence of FWR mutations the framework residues were reverted to the Ab's germline counterpart (FWR-GL) and binding and neutralizing properties were then evaluated. 412d was used in comparing the Ab framework amino acid replacement vs. interactive surface area on Ab. Klein2013 (neutralization, structure, antibody lineage)
412d: Intrinsic reactivity of HIV-1, a new property regulating the level of both entry and sensitivity to Abs has been reported. This activity dictates the level of responsiveness of Env protein to co-receptor, CD4 engagement and Abs. CD4 independence of the glycoprotein variants exhibits strong correlation with 412d binding. The binding increases significantly with N197S gp41 change but little with J1Hx gp41. Haim2011 (antibody interactions)
412d: Crystal structures of unliganded core gp120 from HIV-1 clade B, C, and E were determined to understand the mechanism of CD4 binding capacity of unliganded HIV-1. The results suggest that the CD4 bound conformation represents "a ground state" for the gp120 core with variable loop. 412d was used as a control to prove whether the purified and crystallized gp120 is in the CD4 bound conformational state or not. Kwon2012 (structure)
412d: To improve the immunogenicity of HIV-1 Env vaccines, a chimeric gp140 trimer in which V1V2 region was replaced by the GM-CSF cytokine was constructed. We selected GM-CSF was selected because of its defined adjuvant activity. Chimeric EnvGM-CSF protein enhanced Env-specific Ab and T cell responses in mice compared with wild-type Env. Probing with neutralizing antibodies showed that both the Env and GM-CSF components of the chimeric protein were folded correctly. 3 proteins were studied: Env-wild-type, Env-ΔV1V2, Env-hGM-CSF. In the absence of CD4, the CD4i epitope MAb 17b, 48d, and 412d bound poorly to Env-wild-type and Env-hGM-CSF but efficiently to Env-ΔV1V2. Adding soluble CD4 substantially increased the binding of these MAb to Env-ΔV1V2 and especially to Env-wild-type, but binding to Env-hGM-CSF was improved only modestly, suggesting that the presence of GM-CSF in the V1V2 region either limits the accessibility of the CD4i epitopes or blocks the conformational changes that expose them. vanMontfort2011 (vaccine antigen design)
412d: Broadly neutralizing HIV-1 immunity associated with VRC01-like antibodies was studied by isolation of VRC01-like neutralizers with CD4bs probe; structural definition of gp120 recognition by RSC3-identified antibodies from different donors; functional complementation of heavy and light chains among VRC01-like antibodies; identification of VRC01 antibodies by 454 pyrosequencing; and cross-donor phylogenetic analysis of sequences derived from the same precursor germline gene. 412d was studied among other antibodies that derive from a common IGHV1-69 allele to assess how atypical the VRC01-like antibody convergence was. T The angular difference in heavy-chain orientation between 17b, 412d, and X5 was over 90°, or roughly 10 times as much as among the VRC01-like antibodies. Wu2011 (structure)
412d: Crystal structures of gp120 and gp41 in complex with CD4 and/or MAbs 17b, 48d, b12, b13, 412d, X5, 211C, C11, 15e, m6, m9 and F105 were used to determine the structure and the mobility of the gp41-interactive region of gp120. Elements determined to maintain the gp120-gp41 interaction were the gp120 termini and a newly described invariant 7-stranded β-sandwich. Structurally plastic elements of gp120 responsible for the various gp120 conformation changes due to receptor- or Ab-binding were structured into 3 layers, with the V1/V2 loops emanating from layer 2 and the highly glycosylated outer domain from layer 3. Pancera2010a (antibody binding site, structure)
412d: 21c binding, autoreactivity, polyreactivity and protective benefits are discussed and compared to other autoreactive MAbs, such as 2F5 and 4E10. Regulation of CD4i MAbs, such as 21c and 412d, by tolerance mechanisms is discussed. Haynes2010 (autoantibody or autoimmunity, antibody polyreactivity)
412d: Expression of gp120 was shown to lead to the accumulation of both monomeric gp120 and aberrant dimeric gp120 forms. Dimeric forms of gp120 were not recognized by CD4i MAbs, such as 412d, nor by MAbs against the gp120 inner domain, but were recognized by CD4BS MAbs. It is suggested that gp120 dimerization occludes or disrupts the inner domain and/or the co-receptor binding site. Formation of gp120 dimers was reduced by removal of the V1/V2 loops or the N and C termini. Finzi2010 (antibody binding site)
412d: A set of Env variants with deletions in V1/V2 was constructed. Replication competent Env variants with V1/V2 deletions were obtained using virus evolution of V1/V2 deleted variants. Sensitivity of the evolved ΔV1V2 viruses was evaluated to study accessibility of their neutralization epitopes. In the absence of sCD4, 412d bound better to the cleaved and uncleaved ΔV1V2 trimers than to the full-length trimer. For cleaved variants, addition of sCD4 did not enhance 412d binding, as it was close to optimal without sCD4. However, the binding of 412d was enhanced by addition of sCD4 for uncleaved variants. 412d did not bind a ΔV1V2 virus carrying V120K substitution. Binding analyses of other CD4i Abs yielded slightly different results, indicating that various CD4i epitopes may be shielded to slightly different extents by the V1V2 domain. Bontjer2010 (antibody binding site, binding affinity)
412d: Fusion of CD4 with 412d scFv resulted in CD4-scFv412d reagent with neutralization potency comparable to other CD4-CD4i complexes. The neutralization potency was improved by inclusion of an IgG Fc region and by linkage of CD4 to the heavy chain of 412d. The resulting CD4hc-IgG1412d neutralized a range of clade A, B and C viruses. West2010 (neutralization, variant cross-reactivity, subtype comparisons)
412d: 412d precise post-translational mimicry mode of epitope recognition is reviewed in detail. The review also summarizes on how different modes of Ab binding and recognition are used to overcome viral evasion tactics and how this knowledge may be used to re-elicit responses in vivo. Kwong2009a (antibody binding site, review)
412d: The crystal structure for VRC01 in complex with an HIV-1 gp120 core from a clade A/E recombinant strain was analyzed to understand the structural basis for its neutralization breadth and potency. The number of mutations from the germline and the number of mutated contact residues for 412d were smaller than those for VRC01. Zhou2010 (neutralization, structure)
412d: Tyrosine sulfates of 412d had a large effect on its activity, where tyrosine sulfation at positions H100, H100c, or dual sulfation at both positions lead to an increase in affinity for gp120 of, 4.5-fold, 212-fold, and 500-fold, respectively, compared to non-sulfated Ab. Evolving 412d beyond the known sequence constraints required for posttranslational sulfation resulted in sulfated 412d variants binding to gp120 as good as 412d. Liu2009a (kinetics, binding affinity)
412d: The Ig usage for variable heavy chain of this Ab was as follows: IGHV:1-69*01, IGHD:4-4, D-RF:2, IGHJ:2. Non-V3 mAbs preferentially used the VH1-69 gene segment. In contrast to V3 mAbs, these non-V3 mAbs used several VH4 gene segments and the D3-9 gene segment. Similarly to the V3 mAbs, the non-V3 mAbs used the VH3 gene family in a reduced manner. Anti-CD4i mAbs exclusively used the VH1 gene family. Gorny2009 (antibody sequence)
4.12D: Two chimeras were constructed from a new HIV-2KR.X7 proviral scaffold where the V3 region was substituted with the V3 from HIV-1 YU2 and Ccon, generating subtype B and C HIV-2 V3 chimera. Both chimera, and the wildtype HIV-2KR and its derivatives HIV-2KR.X4 and HIV-2KR.X7 were resistant to neutralization by 4.12D. Davis2009 (neutralization)
412D: This review provides information on the HIV-1 glycoprotein properties that make it challenging to target with neutralizing Abs. 412D neutralization properties and binding to HIV-1 envelope, and current strategies to develop versions of the Env spike with functional trimer properties for elicitation of broadly neutralizing Abs, are discussed. In addition, approaches to target cellular molecules, such as CD4, CCR5, CXCR4, and MHC molecules, with therapeutic Abs are reviewed. Phogat2007 (review)
412d: 412d structure, sulfation, and binding are reviewed in detail. Lin2007 (review)
412d: Docking of a functional 14-residue CCR5 N-terminus peptide to the crystal structure of gp120-CD4 in complex with sulfated MAb 412d showed that the peptide binds to the base of the V3 loop in a manner similar to that of 412d. To improve peptide stability, sulfo-tyrosine isosteres were incorporated into the peptide, and its solubility was improved by incorporation of an orthogonally functionalized azido tris (ethylenoxy) L-alanine residue. 412d was able to compete and inhibit peptide binding to gp120-CD4. The peptide was used to develop screening assays for small molecule inhibitors of HIV-1 gp120 and CCR5 interactions. Lam2008 (antibody binding site, co-receptor, structure)
412d: Nuclear magnetic resonance and x-ray crystallography used to analyze the structure of the CCR5 N terminus and 412d in complex with gp120 and CD4 revealed surprisingly different conformations of tyrosine-sulfated regions of CCR5 and 412d. However, a critical sulfotyrosine on CCR5 (residue 14) and on 412d (residue 100c) induced similar structural rearrangements in gp120. Furthermore, the gp120 residues that line the sulfotyrosine binding pocket were highly conserved. The structural analyses indicate that engagement of the CCR5 N terminus by gp120 requires formation of a conserved pocket for sulfotyrosine binding, and converts the flexible V3 stem into a rigid β-hairpin. Huang2007b (antibody binding site, structure)
412d: The structure of the V3 region in the context of gp120 core complexed to the CD4 receptor and to the 412d Ab was attempted to be determined by X-ray resolution, but only the structure for V3 complexed with CD4 and X5 Ab was solved. Huang2005 (structure)
412d: Binding of 412d to gp120 requires the gp120 β19 strand and the base of the V3 loop, indicating that the epitope for this Ab includes these two regions. The major determinants of 412d preference for CCR5-using HIV-1 strains were determined to be amino acid residues 325 and 326 in the base of the V3 loop. The close mimicry of the CCR5 N terminus by 412d was emphasized by showing that replacement of the CCR5 N terminus by 412d heavy chain CDR3 loop resulted in a functional HIV-1 co-receptor. Xiang2005 (antibody binding site, co-receptor)
412d: This review focuses on the importance of neutralizing Abs in protecting against HIV-1 infection, including mechanisms of Ab interference with the viral lifecycle, Ab responses elicited during natural HIV infection, and use of monoclonal and polyclonal Abs in passive immunization. In addition, vaccine design strategies for eliciting of protective broadly neutralizing Abs are discussed. MAbs included in this review are: 2F5, Clone 3 (CL3), 4E10, Z13, IgG1b12, 2G12, m14, 447-52D, 17b, X5, m16, 47e, 412d, E51, CM51, F105, F425, 19b, 2182, DO142-10, 697-D, 448D, 15e and Cβ1. McCann2005 (antibody binding site, co-receptor, neutralization, review)
412d: 412d was obtained from an HIV-1 infected individual with a potent ELISA response to the gp120. It was shown that this MAb heavy chain is sulfate-modified. The sulfates of 412d were present exclusively on tyrosines of its heavy chain CDR3 and they contributed to the binding of this MAb to the gp120 of at least three primary HIV isolates. Binding efficiency of 412d to ADA gp120 was doubled in the presence of CD4, showing that this MAb is a CD4-induced. Association of 412d with ADA gp120-CD4-Ig complex was partially inhibited by a sulfated peptide with a sequence corresponding to the CCR5 amino terminus, indicating that 412d binds a CD4-enhanced epitope overlapping the binding domain of CCR5 amino terminus. Neutralization assays showed that 412d neutralizes primary R5 and R5X4 isolates more efficiently, and X4 isolates less efficiently, than CD4i Abs 17b and 48d. Furthermore, 412d scFv was more than 10 times as potent as full-length 412d at neutralizing ADA. scFv 412d was shown to efficiently bind to gp120 of three R5 isolates but not to the HXBc2 X4 isolate. Choe2003 (antibody binding site, co-receptor, neutralization, antibody sequence)
412d: The CDR3 regions of CD4i Abs (E51, 412d, 17b, C12 and 47e) were cloned onto human IgG1 and tested for their ability to inhibit CCR5 binding. Only E51 successfully immunoprecipitated gp120. Dorfman2006 (co-receptor)

References

Showing 34 of 34 references.

Gardner2016 Matthew R. Gardner, Christoph H. Fellinger, Neha R. Prasad, Amber S. Zhou, Hema R. Kondur, Vinita R. Joshi, Brian D. Quinlan, and Michael Farzan. CD4-Induced Antibodies Promote Association of the HIV-1 Envelope Glycoprotein with CD4-Binding Site Antibodies. J. Virol., 90(17):7822-7832, 1 Sep 2016. PubMed ID: 27334589. Show all entries for this paper.

Huang2007b Chih-chin Huang, Son N. Lam, Priyamvada Acharya, Min Tang, Shi-Hua Xiang, Syed Shahzad-ul Hussan, Robyn L. Stanfield, James Robinson, Joseph Sodroski, Ian A. Wilson, Richard Wyatt, Carole A. Bewley, and Peter D. Kwong. Structures of the CCR5 N Terminus and of a Tyrosine-Sulfated Antibody with HIV-1 gp120 and CD4. Science, 317(5846):1930-1934, 28 Sep 2007. PubMed ID: 17901336. Show all entries for this paper.

Kwong2009a Peter D. Kwong and Ian A. Wilson. HIV-1 and Influenza Antibodies: Seeing Antigens in New Ways. Nat. Immunol., 10(6):573-578, Jun 2009. PubMed ID: 19448659. Show all entries for this paper.

Lam2008 Son N. Lam, Priyamvada Acharya, Richard Wyatt, Peter D. Kwong, and Carole A. Bewley. Tyrosine-Sulfate Isosteres of CCR5 N-Terminus as Tools for Studying HIV-1 Entry. Bioorg. Med. Chem., 16(23):10113-10120, Dec 1 2008. PubMed ID: 18952441. Show all entries for this paper.

Liu2009a Chang C. Liu, Hyeryun Choe, Michael Farzan, Vaughn V. Smider, and Peter G. Schultz. Mutagenesis and Evolution of Sulfated Antibodies Using an Expanded Genetic Code. Biochemistry, 48(37):8891-8898, 22 Sep 2009. PubMed ID: 19715291. Show all entries for this paper.

Xiang2005 Shi-Hua Xiang, Michael Farzan, Zhihai Si, Navid Madani, Liping Wang, Eric Rosenberg, James Robinson, and Joseph Sodroski. Functional Mimicry of a Human Immunodeficiency Virus Type 1 Coreceptor by a Neutralizing Monoclonal Antibody. J. Virol., 79(10):6068-6077, May 2005. PubMed ID: 15857992. Show all entries for this paper.

Displaying record number 2163

Download this epitope record as JSON.

MAb ID	VRC01 (VRC01_d45, VRC-HIVMAB060-00-AB)
HXB2 Location	Env	Env Epitope Map
Author Location	gp120
Epitope	(Discontinuous epitope)
Subtype	B
Ab Type	gp120 CD4BS
Neutralizing	tier 2 View neutralization details
Contacts and Features	View contacts and features
Species (Isotype)	human(IgG1)
Patient	NIH45
Immunogen	HIV-1 infection
Keywords	acute/early infection, ADCC, adjuvant comparison, antibody binding site, antibody gene transfer, antibody generation, antibody interactions, antibody lineage, antibody polyreactivity, antibody sequence, assay or method development, autoantibody or autoimmunity, autologous responses, binding affinity, bispecific/trispecific, broad neutralizer, CD4+ CTL, chimeric antibody, computational epitope prediction, contact residues, dynamics, elite controllers, enhancing activity, escape, genital and mucosal immunity, germline, glycosylation, HAART, ART, HIV reservoir/latency/provirus, HIV-2, immunoprophylaxis, immunotherapy, junction or fusion peptide, kinetics, memory cells, mother-to-infant transmission, neutralization, novel epitope, polyclonal antibodies, rate of progression, review, structure, subtype comparisons, therapeutic vaccine, vaccine antigen design, vaccine-induced immune responses, variant cross-reactivity, viral fitness and reversion

Notes

Showing 222 of 222 notes.

VRC01: Analyses of all PDB HIV1-Env trimer (prefusion, closed) structures fulfilling certain parameters of resolution were performed to classify them on the basis of (a) antibody class which was informed by parental B cells as well as structural recognition, and (b) Env residues defining recognized HIV epitopes. Structural features of the 206 HIV epitope and bNAb paratopes were correlated with functional properties of the breadth and potency of neutralization against a 208-strain panel. bNAbs with >25% breadth of neutralization belonged to 20 classes of antibody with a large number of protruding loops and somatic hypermutation (SHM). HIV epitopes recognized placed the bNAbs into 6 categories (viz. V1V2, Glycan-V3, CD4-binding site, Silent face center, Fusion peptide and Subunit Interface). The epitopes contained high numbers of independent sequence segments and glycosylated surface area. VRC01-Env formed a distinct group within the CD4bs category, Class VRC01. Crystal structure data at 3.4A resolution of fully glycosylated Clade G X1193.ct SOSIP.664 prefusion trimer with VRC01 as well as PGT122 and 35O22 was found in PDB ID: 5FYJ. Chuang2019 (antibody binding site, antibody interactions, binding affinity, antibody sequence, structure, antibody lineage, broad neutralizer)
VRC01: In an effort to identify new Env immunogens able to elicit bNAbs, this study looked at Envs derived from rare individuals who possess bNAbs and are elite viral suppressors, hypothesizing that in at least some people the antibodies may mediate durable virus control. The Env proteins recovered from these individuals may more closely resemble the Envs that gave rise to bNAbs compared to the highly diverse viruses isolated from normal progressors. This study identified a treatment-naive elite suppressor, EN3, whose serum had broad neutralization. The Env sequences of EN3 had much fewer polymorphisms, compared to those of a normal progressor, EN1, who also had broad serum neutralization. This result confirmed other reports of slower virus evolution in elite suppressors. EN3 Envelope proteins were unusual in that most possessed two extra cysteines within an elongated V1 region. The impact of the extra cysteines on the binding to bNAbs, virus infectivity, and sensitivity to neutralization suggested that structural motifs in V1 can affect infectivity, and that rare viruses may be prevented from developing escape. As part of this study, the neutralization of pseudotype viruses for EN3 Env clones was assayed for several bnAbs (PG9, PG16, PGT145, PGT121, PGT128, VRC01, 4E10, and 35O22). Hutchinson2019 (elite controllers, neutralization, vaccine antigen design, polyclonal antibodies)
VRC01: This review focuses on the potential for bnAbs to induce HIV-1 remission, either alone or in combination with latency reversing agents, therapeutic vaccines, or other novel therapeutics. Ongoing human trials aimed at HIV therapy or remission are utilizing the following antibodies, alone or in combination: VRC01, VRC01-LS, VRC07-523-LS, 3BNC117, 10-1074, 10-1074-LS, PGT121, PGDM1400, 10E8.4-iMab, and SAR441236 (trispecific VRC01/PGDM1400-10E8v4). Ongoing non-human primate studies aimed to target, control, or potentially eliminate the viral reservoir are utilizing the following antibodies, alone or in combination: 3BNC117, 10-1074, N6-LS, PGT121, and the GS9721 variant of PGT121. Hsu2021 (immunotherapy, review)
VRC01: A series of mutants was produced in the CAP256-VRC26.25 heavy chain, for the purpose of avoiding the previously-identified proteolytic cleavage at position K100m. Neutralization of the mutants was tested, and the cleavage-resistant variant that showed the greatest potency was K100mA. In addition to the K100mA mutation, an LS mutation was added to the Fc portion of the heavy chain, as this change has been shown to improve the half-life of antibodies used for passive administration without affecting neutralization potency. The resulting construct was named CAP256V2LS. The pharmacokinetics of CAP256V2LS were assessed in macaques and mice, and it showed a profile similar to other antibodies used for immunotherapy. The antibody lacked autoreactivity. Structural analysis of wild-type CAP256-VRC26.25 showed that the K100m residue is not involved in interaction with the Env trimer. Previously-published neutralization data for VRC01 and VRC01-LS were used for comparison purposes. Zhang2022 (neutralization, immunotherapy, broad neutralizer)
VRC01: Rabbits were immunized with a DNA vaccine encoding JR-CSF gp120. Five sera with potent autologous neutralizing activity were selected and compared with a human neutralizing plasma (Z23) and monoclonal antibodies targeting various regions of gp120 (VRC01, b12, b6, F425, 2F5, 2G12, and X5). The rabbit sera contained different neutralizing activities dependent on C3 and V5, C3 and V4, or V4 regions of the glycan-rich outer domain of gp120. All sera showed enhanced neutralizing activity toward an Env variant that lacked a glycosylation site in V4. The JR-CSF gp120 epitopes recognized by the sera were distinct from those of the mAbs. The activity of one serum required specific glycans that are also important for 2G12 neutralization, and this serum blocked the binding of 2G12 to gp120. The findings show that different fine specificities can achieve potent neutralization of HIV-1, yet this strong activity does not result in improved breadth. Narayan2013 (neutralization, polyclonal antibodies)
VRC01: The study compared well-characterized nAbs (2G12, b12, VRC01, 10E8, 17b) with 4 mAbs derived from a Japanese patient (4E9C, 49G2, 916B2, 917B11), in their neutralization and ADCC activity against viruses of subtypes B and CRF01. CRF01 viruses were less susceptible to neutralization by 2G12 and b12, while VRC01 was highly effective in neutralizing CRF01 viruses. 49G2 showed better neutralization breadth against CRF01 than against B viruses. CRF01_AE viruses from Japan also showed a slightly higher susceptibility to anti-CD4i Ab 4E9C than the subtype B viruses, and to CRF01_AE viruses from Vietnam. Neutralization breadth of other anti-CD4i Abs 17b, 916B2 and 917B11 was low against both subtype B and CRF01_AE viruses. Anti-CD4bs Ab 49G2, which neutralized only 22% of the viruses, showed the broadest coverage of Fc-mediated signaling activity against the same panel of Env clones among the Abs tested. The CRF01_AE viruses from Japan were more susceptible to 49G2-mediated neutralization than the CRF01_AE viruses from Vietnam, but Fc-mediated signaling activity of 49G2was broader and stronger in the CRF01_AE viruses from Vietnam than the CRF01_AE viruses from Japan. Thida2019 (ADCC, neutralization, subtype comparisons)
VRC01: An R5 virus isolated from chronic patient NAB01 (Patient Record# 4723) was adapted in culture to growth in the presence of target cells expressing reduced levels of CD4. Entry kinetics of the virus were altered, and these alterations resulted in extended exposure of CD4-induced neutralization-sensitive epitopes to CD4. Adapted and control viruses were assayed for their neutralization by a panel of neutralizing antibodies targeting several different regions of Env (PGT121, PGT128, 1-79, 447-52d, b6, b12, VRC01, 17b, 4E10, 2F5, Z13e1). Adapted viruses showed greater sensitivity to antibodies targeting the CD4 binding site and the V3 loop. This evolution of Env resulted in increased CD4 affinity but decreased viral fitness, a phenomenon seen also in the immune-privileged CNS, particularly in macrophages. Beauparlant2017 (neutralization, viral fitness and reversion, dynamics, kinetics)
VRC01: The Chinese HIV Reference Laboratory produced 124 pseudoviruses from patients with subype B, BC, and CRF01 infections. These viruses were assigned to tiers based on their neutralization by a panel of patient sera. Their neutralization sensitivities were also measured against a panel of well-characterized mAbs (2F5, b12, 2G12, 4E10, 10E8, VRC01, VRC-CH31, CH01, PG9, PG16, PGT121, PGT126). Nie2020 (assay or method development, neutralization)
VRC01: In 8 ART-treated patients, latent viruses were induced by a viral outgrowth assay and assayed for their sensitivity to neutralization by 8 broadly neutralizing antibodies (VRC01, VRC07-523, 3BNC117, PGT121, 10-1074, PGDM1400, VRC26.25, 10E8v4-V5F-100cF). The patients' inducible reservoir of autologous viruses was generally refractory to neutralization, and higher Env diversity correlated with greater resistance to neutralization. Wilson2021 (autologous responses, neutralization, HIV reservoir/latency/provirus)
VRC01: Extensive structural and biochemical analyses demonstrated that PGT145 achieves recognition and neutralization by targeting quaternary structure of the cationic trimer apex with long and unusually stabilized anionic β-hairpin HCDR3 loops. In BG505.Env.C2 alanine-scanning neutralization assays, VRC01 had more similar results to hammerhead-class antibodies PG9 & CH01 than to PGT145-like antibodies. Lee2017 (antibody binding site, neutralization)
VRC01: Novel Env pseudoviruses were derived from 22 patients in China infected with subtype CRF01_AE viruses. Neutralization IC50 was determined for 11 bNAbs: VRC01, NIH45-46G54W, 3BNC117, PG9, PG16, 2G12, PGT121, 10-1074, 2F5, 4E10, and 10E8. The CRF01_AE pseudoviruses exhibited different susceptibility to these bNAbs. Overall, 4E10, 10E8, and 3BNC117 neutralized all 22 env-pseudotyped viruses, followed by NIH45-46G54W and VRC01, which neutralized more than 90% of the viruses. 2F5, PG9, and PG16 showed only moderate breadth, while the other three bNAbs neutralized none of these pseudoviruses. Specifically, 10E8, NIH45-46G54Wand 3BNC117 showed the highest efficiency, combining neutralization potency and breadth. Mutations at position 160, 169, 171 were associated with resistance to PG9 and PG16, while loss of a potential glycan at position 332 conferred insensitivity to V3-glycan-targeting bNAbs. These results may help in choosing bNAbs that can be used preferentially for prophylactic or therapeutic approaches in China. Wang2018a (assay or method development, neutralization, subtype comparisons)
VRC01: A novel CD4bs bNAb, 1-18, is identified with breadth (97% against a 119-strain multiclade panel) and potency exceeding (IC₅₀ = 0.048 µg/mL) most V_H1-46 and V_H1-2 class bNAbs like 3BNC117, VRC01, N6, 8ANC131, 10-1074, PGT151, PGT121, 8ANC195, PG16 and PGDM1400. 1-18 effectively restricts viral escape better than bNAbs 3BNC117 and VRC01. While 1-18 targets the CD4bs like VRC01-like Abs, it recognizes the epitope differently. Neutralizing activity against VRC01 Ab-class escapes is maintained by 1-18. In humanized mice infected by strain 1_YU2, viral suppression is also maintained by 1-18. V_H1-46-derived B cell clone 4.1 from patient IDC561 produced potent, broadly active Abs. Subclone 4.1 is characterized by a 6 aa CDRH1 insertion lengthening it from 8 to 14 aa. and produces bNAbs 1-18 and 1-55. Cryo-EM at 2.5A of 1-18 in complex with BG505_SOSIP.664 suggests their insertion increases inter-protomer contacts by a negatively charged DDDPYTDDD motif, resulting in an enlargement of the buried surface on HIV-1 gp120. Variations in glycosylation is thought to confer higher neutralizing activity on 1-18 over 1-55. Schommers2020 (antibody binding site, antibody generation, antibody interactions, neutralization, escape, binding affinity, antibody sequence, structure, broad neutralizer, contact residues)
VRC01: Soluble versions of HIV-1 Env trimers (sgp140 SOSIP.664) stabilized by a gp120-gp41 disulfide bond and a change (I559P) in gp41 have been structurally characterized. Cross-linking/mass spectrometry to evaluate the conformations of functional membrane Env and sgp140 SOSIP.664 has been reported. Differences were detected in the gp120 trimer association domain and C terminus and in the gp41 HR1 region which can guide the improvement of Env glycoprotein preparations and potentially increasing their effectiveness as a vaccine. VRC01 broadly neutralized HIV-1AD8 full-length and cytoplasmic tail-deleted Envs. Castillo-Menendez2019 (vaccine antigen design, structure)
VRC01: In an attempt to engage appropriate germline B cells that give rise to bNAbs, a combination of Env glycan modifications that permit far greater neutralization potency by near germline forms of multiple VRC01-class bNAbs were tested. The authors assessed CD4bs bNAbs for neutralizing activity against of Env-pseudotyped viruses (EPV) that were either Man5-enrichment and/or had targeted glycan deletion and concluded that neutralization by germline-reverted forms of VRC01-class bNAbs requires a combination of both Man5-enrichment and glycan deletion. In particular, Man5-enrichment increased the sensitivity of 426c by 8–12 fold when assayed with mature VRC01, 3BNC117, VRC-CH31 and CH103, and this sensitivity increased further by targeted glycan deletion. Furthermore, Man5-enrichment increased the sensitivity of subtype C transmitted-founder 426c EPV that lacked glycan N276, and those that lacked two glycans at N460 and N463, to mature VRC01 by ˜10-fold. LaBranche2018 (antibody interactions, antibody lineage)
VRC01: Expanding on previous work aimed at understanding the germline VRC01-class antibody-recognition potential of the previously described 426c Env, the authors characterize the crystal structure, binding and contacts to the germline VRC01 of two C Env constructs: the previously described soluble trimeric 426c SOSIP with three NLGSs removed at positions Asn276, Asn460, and Asn463; and a monomeric 426c core containing all wild-type NLGSs (including those at positions Asn276, Asn460, and Asn463), but lacking variable loops 1, 2, and 3. The authors test and characterize various glycan-deleted combinations and NLGS backbones and demonstrate that germline VRC01 could bind to a 426c core construct in the presence of all naturally occurring NLGSs surrounding the CD4BS, including the NLGS at position Asn276 and with its associated glycan. Borst2018 (antibody interactions, antibody lineage)
VRC01: Lipid-based nanoparticles for the multivalent display of trimers have been shown to enhance humoral responses to trimer immunogens in the context of HIV vaccine development. After immunization with soluble MD39 SOSIP trimers (a stabilized version of BG505), trimer-conjugated liposomes improved both germinal center B cell and trimer-specific T follicular helper cell responses. In particular, MD39-liposomes showed high levels of binding by bNAbs such as V3 glycan specific PGT121, V1/V2 glycan specific PGT145, gp120/gp41 interface specific PGT151, CD4 binding site specific VRC01, and showed minimal binding by non-NAbs like CD4 binding site specific B6, and V3 specific 4025 or 39F. Tokatlian2018 (vaccine antigen design, binding affinity)
VRC01: Without SOSIP changes, cleaved Env trimers disintegrate into their gp120 and gp41-ectodomain (gp41_ECTO) components. This study demonstrates that the gp41_ECTO component is the primary source of this Env metastability and that replacing wild-type gp41_ECTO with BG505 gp41_ECTO of the uncleaved prefusion-optimized design is a general and effective strategy for trimer stabilization. A panel of 11 bNAbs, including the CD4-binding site (CD4bs) recognized by VRC01 and b12, was used to assess conserved neutralizing epitopes on the trimer surface, and the main result was that the substitution was found to significantly improve trimer binding to bNAbs VRC01, PGT151, and 35O22, with P values (paired t test) of 0.0229, 0.0269, and 0.0407, respectively. He2018 (antibody interactions, glycosylation, vaccine antigen design)
VRC01: To reduce local V2 flexibility and improve the binding of V2-dependent bNAbs and germline precursor bNAbs, the authors designed BG505 SOSIP.664 trimer variants whose V1 and V2 domains were stabilized by introducing disulfide bonds either within the V2 loop or between the V1 and V2 loops. The resulting SOSIP trimer variants — E153C/K178C, E153C/K178C/G152E and I184C/E190C — have improved reactivity with V2 bNAbs and their inferred germline precursors and are more sensitive to neutralization by V2 bNAbs. Compared with BG505 SOSIP.664, the E153C/R178C V1-V2 disulfide mutant bound the VRC01, PGT151, and 2G12 slightly less well and the G152E compensatory mutation improved VRC01, PGT151, and 2G12 binding. However, there was no change in sensitivity to VRC01 for either mutant virus E153C/K178C/G152E and I184C/E190C. deTaeye2019 (antibody interactions, variant cross-reactivity, binding affinity, structure, broad neutralizer)
VRC01: This study looks at the role of somatic mutations within antibody variable and framework regions (FWR) in bNAbs and how these mutations alter thermostability and neutralization as the Ab lineage reaches maturation. The emergence and selection of different mutations in the complementarity-determining and framework regions are necessary to maintain a balance between antibody function and stability. The study shows that all major classes of bnAbs (DH2070, CH103, CH235 etc.) have lower thermostability than their corresponding inferred UCA antibodies. Henderson2019 (neutralization, antibody lineage, broad neutralizer)
VRC01: The authors used nuclear magnetic resonance (NMR) to define the structure of the HIV-1 MPER when linked to the transmembrane domain (MPER-TMD) in the context of a lipid bilayer. In particular, they looked at the accessibility of the MPER-TMD to 2F5, 4E10, 10E8 and DH570. The MPER appears to be accessible up to ∼10% of the time to the 2F5, 4E10, and 10E8 Fabs but ∼40% of time to the DH570 Fab. To assess possible functional roles for the MPER in membrane fusion, they generated 17 Env mutants using the sequence of a clade A isolate, 92UG037.8, mutating each of the three structural elements: hydrophobic core, turn, and kink. Mutants W670A (hydrophobic core), F673A (turn), and W680A (kink), while still sensitive to VRC01, became much more resistant to the trimer-specific bNAbs and also gained sensitivity to b6, 3791, and 17b. All mutants with changes at W666 in the hydrophobic core and K683 at the kink lost infectivity almost completely. For the rest of the mutants, infectivity ranged from 4.3 to 50.8% of that of the wild type, showing that key residues important for stabilizing the MPER structure are also critical for Env-induced membrane fusion activity, especially in the context of viral infection. Fu2018 (antibody binding site, antibody interactions, neutralization, variant cross-reactivity, binding affinity, structure)
VRC01: Two HIV-1-infected individuals, VC10014 and VC20013, were monitored from early infection until well after they had developed broadly neutralizing activity. The bNAb activity developed about 1 year after infection and mapped to a single epitope in both subjects. Isolates from each subject, taken at five different time points, were tested against monoclonal bNAbs: VRC01, B12, 2G12, PG9, PG16, 4E10, and 2F5. In subject VC10014, the bNAb activity developed around 1 year postinfection and targeted an epitope that overlaps the CD4-BS and is similar to (but distinct from) bNAb HJ16. In the case of VC20013, the bNAb activity targeted a novel epitope in the MPER that is critically dependent on residue 677 (mutation K677N). All of the isolates from subject VC20013 were very susceptible to bNAbs that target the CD4 binding site (CD4-BS), including b12 and VRC01. Sather2014 (neutralization, broad neutralizer)
VRC01: This study demonstrated that bNAb signatures can be utilized to engineer HIV-1 Env vaccine immunogens eliciting Ab responses with greater neutralization breadth. Data from four large virus panels were used to comprehensively map viral signatures associated with bNAb sensitivity, hypervariable region characteristics, and clade effects. The bNAb signatures defined for the V2 epitope region were then employed to inform immunogen design in a proof-of-concept exploration of signature-based epitope targeted (SET) vaccines. V2 bNAb signature-guided mutations were introduced into Env 459C to create a trivalent vaccine which resulted in increased breadth of NAb responses compared with Env 459C alone. The G458Y signature mutation conferred complete resistance (IC50 > 25 mg/mL) to VRC01 and can neutralize the CH505 TF (IC50 of 0.14mg/mL).VRC01 have reduced breadth and potency against C clade viruses. Bricault2019 (antibody binding site, vaccine antigen design, computational epitope prediction, broad neutralizer)
VRC01: In vitro neutralization data against 25 subtype A, 100 C, and 20 D pseudoviruses of 8 bNAbs (3BNC117, N6, VRC01, VRC07-523LS, CAP256-VRC26.25, PGDM1400, 10–1074, PGT121) and 2 bispecific Abs under clinical development (10E8-iMAb, 3BNC117-PGT135) was studied to assess the antibodies’ potential to prevent infection by dominant HIV-1 subtypes in sub-Saharan Africa. In vivo protection of these Abs and their 2-Ab combination was predicted using a function of in vitro neutralization based on data from a macaque simian-human immunodeficiency virus (SHIV) challenge study. Conclusions were that 1. bNAb combinations outperform individual bNAbs 2. Different bNAb combinations were optimal against different HIV subtypes 3. Bispecific 10E8-iMAb outperformed all combinations and 4. 10E8-iMAb in combination with other conventional Abs was predicted to be the best combination against HIV-infection. Wagh2018 (immunotherapy)
VRC01: A novel antibody, Y498, was derived from donor XJ1981, whose serum had potent and broad neutralization activity. Y498 neutralized 30% of 70 tested HIV-1 isolates and targeted an epitope overlapping the CD4bs of gp120. The neutralization of Y498 was compared to that of 3 other CD4BS antibodies: VRC01, b12, and A16. Sun2017 (antibody generation, neutralization, broad neutralizer)
VRC01: This review summarizes current advances in antibody lineage-based design and epitope-based vaccine design. Antibody lineage-based design is described for VRC01, PGT121 and PG9 antibody classes, and epitope-based vaccine design is described for the CD4-binding site, as well as fusion peptide and glycan-V3 cites of vulnerability. Kwong2018 (antibody binding site, vaccine antigen design, vaccine-induced immune responses, review, antibody lineage, broad neutralizer, junction or fusion peptide)
VRC01: VRC 606 (clinicaltrials.gov NCT02599896) was a single-site Phase I open-label dose-escalation study that evaluated a variant of VRC01, VRC01LS for safety and pharmacokinetic (PK) parameters. VRC01LS has mutations M428L and N434S in the Fc region intended to extend serum half-life, these LS mutations result in enhanced IgG-FcRn binding but do not affect binding to the Fc-gamma receptor and thus do not impair Fc-mediated effector functions, such as antibody dependent cellular cytotoxicity (ADCC). It was observed that VRC01LS was safe and well tolerated and displayed a serum half-life more than four times longer than wild-type VRC01. The VRC01LS Ab retained its neutralizing activity in serum for the 48-week duration of this study, and no Abs were detected to it. Gaudinski2018 (enhancing activity, therapeutic vaccine, immunotherapy, broad neutralizer)
VRC01: This review discusses the identification of super-Abs, where and how such Abs may be best applied, and future directions for the field. VRC01, a prototype super-Ab, was isolated from direct functional screening of thousands of B cell clones. VRC01 is in Phase I clinical development and the Antibody-Mediated Prevention (AMP) study will assess the ability of the VRC01 mAb specific for CD4 binding site to decrease the risk of HIV acquisition in humans. Walker2018 (antibody binding site, review, broad neutralizer)
VRC01: The authors selected an optimal panel of diverse HIV-1 envelope glycoproteins to represent the antigenic diversity of HIV globally in order to be used as antigen candidates. The selection was based on genetic and geographic diversity, and experimentally and computationally evaluated humoral responses. The eligibility of the envelopes as vaccine candidates was evaluated against a panel of antibodies for breadth, affinity, binding and durability of vaccine-elicited responses. The antigen panel was capable of detecting the spectrum of V2-specific antibodies that target epitopes from the V2 strand C (V2p), the integrin binding motif in V2 (V2i), and the quaternary epitope at the apex of the trimer (V2q). Yates2018 (vaccine antigen design, vaccine-induced immune responses, binding affinity)
VRC01: Polyreactive properties of natural and artificially engineered HIV-1 bNAbs were studied, with almost 60% of the tested HIV-1 bNAbs (including this one) exhibiting low to high polyreactivity in different immunoassays. A previously unappreciated polyreactive binding for PGT121, PGT128, NIH45-46W, m2, and m7 was reported. Binding affinity, thermodynamic, and molecular dynamics analyses revealed that the co-emergence of enhanced neutralizing capacities and polyreactivity was due to an intrinsic conformational flexibility of the antigen-binding sites of bNAbs, allowing a better accommodation of divergent HIV-1 Env variants. Prigent2018 (antibody polyreactivity)
VRC01: A systems glycobiology approach was applied to reverse engineer the relationship between bNAb binding and glycan effects on Env proteins. Glycan occupancy was interrogated across every potential N-glycan site in 94 recombinant gp120 antigens. Using a Bayesian machine learning algorithm, bNAb-specific glycan footprints were identified and used to design antigens that selectively alter bNAb antigenicity. The novel synthesized antigens uccessfully bound to target bNAbs with enhanced and selective antigenicity. Yu2018 (glycosylation, vaccine antigen design)
VRC01: This review discusses current HIV bNAb immunogen design strategies, recent progress made in the development of animal models to evaluate potential vaccine candidates, advances in the technology to analyze antibody responses, and emerging concepts in understanding B cell developmental pathways that may facilitate HIV vaccine design strategies. Andrabi2018 (vaccine antigen design, review)
VRC01: A panel of bnAbs were studied to assess ongoing adaptation of the HIV-1 species to the humoral immunity of the human population. Resistance to neutralization is increasing over time, but concerns only the external glycoprotein gp120, not the MPER, suggesting a high selective pressure on gp120. Almost all the identified major neutralization epitopes of gp120 are affected by this antigenic drift, suggesting that gp120 as a whole has progressively evolved in less than 3 decades. Bouvin-Pley2014 (neutralization)
VRC01: Bispecific bNAbs containing anti-CD4bs VRC01 and anti-V3 glycan PGT121 were constructed by linking the single chain (Sc) bNAbs with flexible (G₄S)_n linkers at IgG F_c and were found to have greater neutralization breadth than parental bNAbs when optimal. The optimal bis-specific NAb, dVRC01-5X-PGT121, was one that crosslinked protomers within one Env spike. Combination of this bispecific with a third bNAb, anti-MPER 10E8, gave 99.5%, i.e. nearly pan-neutralization of a 208 virus panel with a geometric mean IC₅₀ below 0.1 µg/ml. Steinhardt2018 (neutralization, immunotherapy, bispecific/trispecific)
VRC01: The first cryo-EM structure of a cross-linked vaccine antigen was solved. The 4.2 Å structure of HIV-1 BG505 SOSIP soluble recombinant Env in complex with a bNAb PGV04 Fab fragment revealed how cross-linking affects key properties of the trimer. SOSIP and GLA-SOSIP trimers were compared for antigenicity by ELISA, using a large panel of mAbs previously determined to react with BG505 Env. Non-NAbs globally lost reactivity (7-fold median loss of binding), likely because of covalent stabilization of the cross-linked ‘closed’ form of the GLA-SOSIP trimer that binds non-NAbs weakly or not at all. V3-specific non-NAbs showed 2.1–3.3-fold reduced binding. Three autologous rabbit monoclonal NAbs to the N241/N289 ‘glycan-hole’ surface, showed a median ˜1.5-fold reduction in binding. V3 non-NAb 4025 showed residual binding to the GLA-SOSIP trimer. By contrast, bNAbs like VRC01 broadly retained reactivity significantly better than non-NAbs, with exception of PGT145 (3.3-5.3 fold loss of binding in ELISA and SPR). Schiffner2018 (vaccine antigen design, binding affinity, structure)
VRC01: This study describes the generation of CHO cell lines stably expressing the following vaccine Env Ags: CRF01_AE A244 Env gp120 protein (A244.AE) and 6240 Env gp120 protein (6240.B). The antigenic profiles of the molecules were assessed with a panel of well-characterized mAbs recognizing critical epitopes and glycosylation analysis confirming previously identified sites and revealing unknown sites at non-consensus motifs. A244.AE gp120 bound to VRC01 in ELISA EC50 and Surface Plasmon Resonance (SPR) assays. 6240.B gp120 bound to VRC01. 6240.B gp120 exhibited binding to VRC01. Wen2018 (glycosylation, vaccine antigen design)
VRC01: The prophylactic and therapeutic potential of an engineered single gene–encoded tandem bispecific immunoadhesin (IA) molecule BiIA-SG was studied. Before engineering BiIAs, codon-optimized scFvs of bNAbs PG9, PG16, PGT128, VRC01, and Hu5A8 were synthesized. The VL/VH domain of each scFv was engineered as a corresponding IA by fusion with human IgG1-Fc to generate IA-PG9, IA-PG16, IA-PGT128, IA-VRC01, and IA-Hu5A8. While all IAs exhibited specific anti–HIV-1 activity, only IA-PGT128 displayed similar potency and the same sigmoidal slope of 100% neutralization as previously described for the native PGT128, and IA-PGT128 in combination with IA-Hu5A8 exhibited the best synergistic effect based on computational synergy volumes. IA-PGT128 and IA-Hu5A8 were therefore used for BiIA construction. Wu2018
VRC01: Prevention of HIV infection by intravenously-administered VRC01 was modeled to predict prevention efficacy (PE) of each 10 mg/kg or 30 mg/kg VRC01 dose. Nonhuman primates (NHPs) were administered high-dose intra-rectal simian-human immunodeficiency virus challenge two days post-VRC01 infusion (“NHP model”). As humans may require greater VRC01 concentration to achieve the same level of protection, it was assumed that 5-fold greater VRC01 serum concentration would be needed to provide the same level of per-exposure PE as seen in the NHP data (“5-fold model”). For the 10 mg/kg regimen, the 5-fold and NHP models predict an overall PE of 37% and 64%, respectively; for the 30 mg/kg regimen, the two models predict an overall PE of 53% and 82%, respectively. Huang2018 (immunoprophylaxis)
VRC01: Assays of poly- and autoreactivity demonstrated that broadly neutralizing NAbs are significantly more poly- and autoreactive than non-neutralizing NAbs. VRC01 is autoreactive, but not polyreactive. Liu2015a (autoantibody or autoimmunity, antibody polyreactivity)
VRC01: This study was designed to evaluate the safety, pharmacological profile, and immune functions of VRC01 administered either subcutaneously or intravenously as a foundation for future efficacy trials. HIV Vaccine Trials Network (HVTN) 104 was designed to evaluate the safety and tolerability of multiple doses of VRC01. Eighty-eight healthy, HIV-uninfected, low-risk participants were enrolled in 6 United States clinical research sites affiliated with the HVTN between September 9, 2014 and July 15, 2015. Participants were randomized to receive the following: a 40 mg/kg IV VRC01 loading dose followed by five 20 mg/kg IV VRC01 doses every 4 weeks (treatment group 1 [T1], n = 20); eleven 5 mg/kg subcutaneous (SC) VRC01 (treatment group 3 [T3], n = 20); placebo (placebo group 3 [P3], n = 4)doses every 2 weeks; or three 40 mg/kg IV VRC01 doses every 8 weeks (treatment group 2 [T2], n = 20). Treatment groups T4 and T5 (n = 12 each) received three 10 or 30 mg/kg IV VRC01 doses every 8 weeks, respectively. Participants were followed for 32 weeks after their first VRC01 administration and received a total of 249 IV infusions and 208 SC injections, with no serious adverse events, dose-limiting toxicities, nor evidence for anti-VRC01 antibodies observed. The limitations of this study include the relatively small sample size of each VRC01 administration regimen and missing data from participants who were unable to complete all study visits. The antibody in serum after administration showed evidence of a number of immune functions that are known to inhibit HIV transmission and replication. Mayer2017 (immunoprophylaxis, immunotherapy)
VRC01: Panels of C clade pseudoviruses were computationally downselected from the panel of 200 C clade viruses defined by Rademeyer et al. 2016. A 12-virus panel was defined for the purpose of screening sera from vaccinees. Panels of 50 and 100 viruses were defined as smaller sets for use in testing magnitude and breadth against C clade. Published neutralization data for 16 mAbs was taken from CATNAP for the computational selections: 10-1074, 10-1074V, PGT121, PGT128, VRC26.25, VRC26.08, PGDM1400, PG9, PGT145, VRC07-523, 10E8, VRC13, 3BNC117, VRC07, VRC01, 4E10. Hraber2017 (assay or method development, neutralization)
VRC01: This study reports host tolerance mechanisms that limit the development of CD4bs and HCDR3-binder bNAbs via sequential HIV-1 Env vaccination. Vaccine-induced macaque CD4bs bnAbs recognize open Env trimers, and accumulate relatively modest somatic mutations. In naive CD4bs, unmutated common ancestor knock-in mice Env + B cell clones develop anergy and partial deletion at the transitional to mature B cell stage, but become Env- upon receptor editing. Stepwise immunization initiates CD4bs-bnAb responses, but immune tolerance mechanisms restrict their development. Crystal structure of DH522 showed footprints of VRC01 and CD4 attachment inhibitor N-(4-bromophenyl)-N′-(2,2,6,6-tetramethylpiperidin-4-yl)ethanediamide (NBD-557). Williams2017a (glycosylation, structure, antibody lineage, chimeric antibody)
VRC01: The immunologic effects of mutations in the Env cytoplasmic tail (CT) that included increased surface expression were explored using a vaccinia prime/protein boost protocol in mice. After vaccinia primes, CT- modified Envs induced up to 7-fold higher gp120-specific IgG, and after gp120 protein boosts, they elicited up to 16-fold greater Tier-1 HIV-1 neutralizing antibody titers. Envs with or without the TM1 mutations were expressed in HEK 293T cells and analyzed for the relative expression of Ab epitopes including the CD4 binding site for VRC01. Hogan2018 (vaccine antigen design)
VRC01: The HIV Vaccine Trials Network and the HIV Prevention Trials Network conducted the first clinical test-of-concept, Antibody Mediated Prevention (AMP) trials to assess whether, and how, intravenous infusion of VRC01, prevents HIV-1 infection. HIV-1 prevention efficacy trials were conducted in two cohorts: 2700 HIV-uninfected men and transgender persons who have sex with men in the United States, Peru, Brazil, and Switzerland; and 1500 HIV-uninfected sexually active women in seven countries in sub-Saharan Africa. Participants were randomized 1:1:1 to receive an intravenous infusion of 10 mg/kg VRC01, 30 mg/kg VRC01, or a control preparation every 8 weeks for a total of 10 infusions. Each trial wasdesigned (1) to assess overall prevention efficacy (PE) pooled over the two VRC01 dose groups vs. control and (2) to assess VRC01 dose and laboratory markers as correlates of protection (CoPs) against overall and genotype- and phenotype-specific infection. Each AMP trial was designed to have 90% power to detect PE > 0% if PE is ≥ 60%. If affirmative, they will provide information for estimating the optimal dosage of VRC01 (or subsequent derivatives) and identify threshold levels of neutralization and Fc effector functions associated with high-level protection. Gilbert2017 (immunoprophylaxis)
VRC01: SOSIP.664 trimer was modified at V3 positions 306 and 308 by Leucine substitution to create hydrophobic interactions with the tryptophan residue at position 316 and the V1V2 domain. These modifications stabilized the resulting SOSIP.v5.2 S306L R308L trimers. In vivo, the induction of V3 non-NAbs was significantly reduced compared with the SOSIP.v5.2 trimers. S306L plus R308L paired substitutions had no effect on the trimer reactivity of VRC01. deTaeye2018 (broad neutralizer)
VRC01: Nanodiscs (discoidal lipid bilayer particles of 10-17 nm surrounded by membrane scaffold protein) were used to incorporate Env complexes for the purpose of vaccine platform generation. The Env-NDs (Env-NDs) were characterized for antigenicity and stability by non-NAbs and NAbs. Most NAb epitopes in gp41 MPER and in the gp120:gp41 interface were well exposed while non-NAb cell surface epitopes were generally masked. Anti-CD4bs NAb VRC01, had a Kd of 14.6 nM and bound the Env-ND well. Witt2017 (vaccine antigen design, binding affinity)
VRC01: In the RV305 HIV-1 vaccine trial, two boosts of either ALVAC-HIV, AIDSVAX B/E gp120 or ALVAC-HIV + AIDSVAX B/E gp120 were given to HIV-1-uninfected RV144 vaccine-recipients. While no bNAb plasma activity was induced in this trial as well, an increased frequency of memory B cells that produce Env-specific anti-CD4bs antibodies with long HCDR3s was detected. In a binding assay, VRC01 binding was reduced by mutants of CRF01_AE Env protein A244. Easterhoff2017 (binding affinity)
VRC01: The DS-SOSIP.4mut is a soluble, closed pre-fusion-state HIV-1 Env trimer that has improved stability and immunogenicity. It has 4 specific alterations at M154, M300, M302 and L320. VRC01 recognizes this trimer. Chuang2017 (antibody interactions)
VRC01: Libraries of BG505 gp120 containing mutations were displayed on yeast and screened for binding to a panel of VRC01-class mAbs. Boosted VRC01 gH mice showed broad neutralization on a panel of N276A viruses, neutralization of fully native virus containing the N276 glycan site was limited to a single heterologous tier 2 isolate and was substantially less potent. The progress of vaccine-induced somatic hyper mutation, SHM, toward mature VRC01 was tested. For each VH1-2 sequence, the total number of amino-acid mutations and the number of amino-acid mutations shared with a panel of VRC01-class mAbs like VRC01, PGV04, PGV20, VRC-CH31, 3BNC60, and 12A12 were determined. Extremely deep Ab repertoire sequencing on two healthy HIV-naive individuals were performed to compute the frequency of randomly incorporated VRC01-class mutations in human VH1-2 Ab sequence. Briney2016 (HIV-2, neutralization, vaccine antigen design)
VRC01: Env variants that lack all 15 core glycan sites were produced. These variants retain conformational integrity and viral infectivity and bind to several bNAbs, including VRC01 and b12, suggesting that Env glycans are not essential to protein folding, and deglycosylated antigens may be useful as priming immunogens. A partially germline-reverted variant of VRC01 (GL-VRC01) was produced to compare its binding to that of VRC01. Rathore2017 (glycosylation, vaccine antigen design)
VRC01: Env trimers were engineered with selective deglycosylation around the CD4 binding site to see if they could be useful vaccine antigens. The neutralization of glycan-deleted trimers was tested for a set of bnAbs (PG9, PGT122, PGT135, b12, CH103, HJ16, VRC01, VRC13, PGT151, 8ANC195, 35O22), and the antigens elicited potent neutralization based on the CD4 supersite. A crystal structure was made of one of these Env trimers bound to Fabs 35O22 and 3H+109L. Guinea pigs vaccinated with these antigens achieved neutralization of deglycosylated Envs. Glycan-deleted Env trimers may be useful as priming antigens to increase the frequency of CD4 site-directed antibodies. Zhou2017 (glycosylation, neutralization, vaccine antigen design, vaccine-induced immune responses)
VRC01: Env from of a highly neutralization-resistant isolate, CH120.6, was shown to be very stable and conformationally-homogeneous. Its gp140 trimer retains many antigenic properties of the intact Env, while its monomeric gp120 exposes more epitopes. Thus trimer organization and stability are important determinants for occluding epitopes and conferring resistance to antibodies. Among a panel of 21 mAbs, CH120.6 was resistant to neutralization by all non-neutralizing and strain-specific mAbs, regardless of the location of their epitopes. It was weakly neutralized by several broadly-neutralizing mAbs (VRC01, NIH45-46, 12A12, PG9, PG16, PGT128, 4E10, and 10E8), and well neutralized by only 2 (PGT145 and 10-1074). Cai2017 (neutralization)
VRC01: Mice twice-primed with DNA plasmids encoding HIV-1 gp120 and gag and given a double boost with HIV-1 virus-like particles (VLPs) i.e. DDVV immunization, elicited Env-specific antibody responses as well as Env- and Gag-specific CTL responses. In vivo electroporation (EP) was used to increase breadth and potency of response. Human anti-gp120 VRC01 was used to prove that the VLP spike included the broad neutralization epitope recognized by it. Huang2017a (therapeutic vaccine, variant cross-reactivity)
VRC01: This review discusses host controls of bNAb responses and why highly antigenic vaccine Envs do not induce bNAbs when used as vaccine immunogens. In Kl mice expressing 3BNC60 germline unmutated common ancestor (UCA), majority of te none marrow B cell were deleted, and peripheral residual B cells were anergic. Vaccination resulted in GL B cells activated with minimal affinity maruration. Kelsoe2017 (review)
VRC01: A panel of mAbs (2G12, VRC01, HJ16, 2F5, 4E10, 35O22, PG9, PGT121, PGT126, 10-1074) was tested to compare their efficacy in cell-free versus cell-cell transmission. Almost all bNAbs (with the exception of anti-CD4 mAb Leu3a) blocked cell-free infection with greater potency than cell-cell infection, and showed greater potency in neutralization of cell-free viruses. The lower effectiveness on neutralization was particularly pronounced for transmitted/founder viruses, and less pronounced for chronic and lab-adapted viruses. The study highlights that the ability of an antibody to inhibit cell-cell transmission may be an important consideration in the development of Abs for prophylaxis. Li2017 (immunoprophylaxis, neutralization)
VRC01: Compared to patient-derived mAbs, vaccine-elicited mAbs are often less able to neutralize the virus, due to a less-effective angle of approach to the Env spike. This study engineered an immunogen consisting of the gp120 core in complex with a CD4bs mAb, 17b. Rabbits immunized with this antigen displayed earlier affinity maturation and better virus neutralization compared to those immunized with the gp120 core alone. The 17b antibody was shown to have a steric clash with two other CD4bs Abs, GE136 and GE148, but not with VRC01. VRC01 and 2G12 bound to the the 17b-gp120 complex more avidly than to the gp120 core alone. Chen2016b (antibody binding site, vaccine antigen design, vaccine-induced immune responses, structure)
VRC01: This study describes a computational method to calculate the binding affinities of antibodies and antigens. The method called free-energy perturbation (FEP) was developed using HIV-1 Env gp120 and 3 VRC01-class mAbs, VRC01, VRC03, and VRC-PG04. Clark2017 (binding affinity, structure)
VRC01: The next generation of a computational neutralization fingerprinting (NFP) being used as a way to predict polyclonal Ab responses to HIV infection is presented. A new panel of 20 pseudoviruses, termed f61, was developed to aid in the assessment of experimental neutralization. This panel was used to assess 22 well-characterized bNAbs and mixtures thereof (HJ16, VRC01, 8ANC195, IGg1b12, PGT121, PGT128, PGT135, PG9, PGT151, 35O22, 10E8, 2F5, 4E10, VRC27, VRC-CH31, VRC-PG20, PG04, VRC23, 12A12, 3BNC117, PGT145, CH01). The new algorithms accurately predicted VRC01-like and PG9-like antibody specificities. Doria-Rose2017 (neutralization, computational epitope prediction)
VRC01: This review focuses on the potential role of HIV-1-specific NAbs in preventing HIV-1 infection. Several NAbs have provided protection from infection in SHIV challenge studies in primates: b12, VRC01, VRC07-523LS, 3BNC117, PG9, PGT121, PGT126, 10-1074, 2G12, 4E10, 2F5, 10E8. Engineered variant VRC01-LS had greater persistence and improved protection against SHIV challenge, compared to VRC01. Pegu2017 (immunoprophylaxis, review)
VRC01: Prevalence, breadth, and potency of NAb responses in 98 CRF07_BC-infected individuals using a multi-subtype panel of 30 tier 2-3 Env-pseudotyped viruses were identified and the neutralization pattern of CRF07_BC-infected people was compared with that of subtype B'-infected individuals in China. 18% of 98 plasma samples neutralized >80% of viruses, and 53% neutralized >50%, suggesting the presence of broadly NAbs. CRF07_BC-infected individuals generated higher but less broad neutralization titers against intra-subtype viruses than subtype B'-infected individuals with longer infection length, indicating the transition from narrow autologous to broad heterologous neutralization over time. Neutralization activity of the top six plasmas from each cohort was attributable to the IgG fraction, and half of them developed CD4 binding site antibody reactivity. VRC01 and 2G12 were used as controls. Hu2017 (broad neutralizer)
VRC01: First population pharmacokinetics (PK) analysis of VRC01 was conducted using 84 HIV-uninfected adults who received multiple-dose intravenous or subcutaneous VRC01 every several weeks. The study demonstrated that a robust PK model of VRC01 could be developed to reliably characterize the observed PK data and to estimate VRC01 concentration values and associated variabilities at any post-dose time-point. Huang2017 (immunoprophylaxis)
VRC01: Novel bNAb, IOMA, combines features of VH_1-2/VRC01-class bNAbs with CD4-mimetic CD4bs bNAbs. It is described in complex to BG505 SOSIP.664 Env trimer by 3.5A and 3.9A-resolution crystal structures. The IOMA-BG505 structure demonstrates that VH1-2*02-derived CD4-mimetic bNAbs are not limited to longer, five-residue CDRL3s as in the case of VRC01. This is the first full description of native glycosylated trimer (untrimmed high-mannose and complex-typle N-glycans) revealing Ab-vulnerable glycan holes. Though derived from VRC01, the shorter CDRL3 makes IOMA resemble am 8ANC131-class/VH1-46-derived CD4bs bNAb. Gristick2016 (glycosylation)
VRC01: This review summarizes vaccine approaches to counter HIV diversity. A structural map illustrated the contact regions of several bNAbs: VRC26.09, PGT128, CH235.12, and 10E8. Structures illustrating the bNAbs' tolerance for sequence variation were illustrated for CH235.12, PGT128, VRC26.09, and 10E8. CD4BS bNAbs such as VRC01 and CH235.12 illustrate that bNAbs bind to both conserved and hypervariable regions of Env. These bNAbs aren't broad because their epitopes are highly conserved, but rather they arise due to selective pressures of the autologous viruses. Korber2017 (antibody binding site, vaccine antigen design, review)
VRC01: In 33 individuals (14 uninfected and 19 HIV-1-infected), intravenous infusion of 10-1074 was well tolerated. In infected individuals with sensitive strains, 10-1074 decreased viremia, but escape variants and viral rebound occurred within a few weeks. Escape variants were also resistant to V3 antibody PGT121, but remained sensitive to antibodies targeting other epitopes (3BNC117, VRC01 or PGDM1400). Loss of the PNGS at position N332 or 324G(D/N)IR327 mutation was associated with resistance to 10-1074 and PGT121. Caskey2017 (escape, immunotherapy)
VRC01: The results confirm that Nef and Vpu protect HIV-1-infected cells from ADCC, but also show that not all classes of antibody can mediate ADCC. Anti-cluster-A antibodies are able to mediate potent ADCC responses, whereas anti-coreceptor binding site antibodies are not. Position 69 in gp120 is important for antibody-mediated cellular toxicity by anti-cluster-A antibodies. The angle of approach of a given class of antibodies could impact its capacity to mediate ADCC. VRC01 and b12 were selected as Abs that recognize the CD4 binding site. Ding2015 (ADCC)
VRC01: The ability of neutralizing and nonneutralizing mAbs to block infection in models of mucosal transmission was tested. Neutralization potency did not fully predict activity in mucosal tissue. CD4bs-specific bNAbs, in particular VRC01, blocked HIV-1 infection across all cellular and tissue models. MPER (2F5) and outer domain glycan (2G12) bNAbs were also efficient in preventing infection of mucosal tissues, while bNAbs targeting V1-V2 glycans (PG9 and PG16) were more variable. Non-nAbs alone and in combinations, were poorly protective against mucosal infection. The protection provided by specific bNAbs demonstrates their potential over that of nonneutralizing antibodies for preventing mucosal entry. VRC01, b12, and CH31 were selected as representative mAbs of the CD4-BS class. Cheeseman2017 (genital and mucosal immunity, immunoprophylaxis)
VRC01: To understand HIV neutralization mediated by the MPER, antibodies and viruses were studied from CAP206, a patient known to produce MPER-targeted neutralizing mAbs. 41 human mAbs were isolated from CAP206 at various timepoints after infection, and 4 macaque mAbs were isolated from animals immunized with CAP206 Env proteins. Two rare, naturally-occuring single-residue changes in Env were identified in transmitted/founder viruses (W680G in CAP206 T/F and Y681D in CH505 T/F) that made the viruses less resistant to neutralization. The results point to the role of the MPER in mediating the closed trimer state, and hence the neutralization resistance of HIV. CH58 was one of several mAbs tested for neutralization of transmitted founder viruses isolated from clade C infected individuals CAP206 and CH505, compared to T/F viruses containing MPER mutations that confer enhanced neutralization sensitivity. Bradley2016a (neutralization)
VRC01: A novel MHC-independent third-generation anti-HIV-1 CAR molecule (CD3ζ-CD28-CD137) has been reported.The extracellular domain is consisted of an scFv region derived from the bNAb VRC01 capable of redirecting the antigen specificity of primary CD8+ T cell populations against gp120. CAR cytoplasmic region, composed of a CD3ζ chain and multiple signaling domains (CD28 and CD137). The VC-CAR-T cells, were able to induce T cell-mediated cytolysis after coculture with gp120-expressing cells and wild-type HIV-1-infected CD4+ T cells. This also effectively induced the cytolysis of LRA-reactivated HIV-1-infected CD4 T lymphocytes isolated from infected individuals receiving sup-pressive cART. The data demonstrates that the special features of genetically engineered CAR-T cells make them a particularly suitable candidate for therapeutic application and constitute an improvement over existing CD4-based CAR-T technology. Liu2016 (CD4+ CTL, immunotherapy)
VRC01: This study performed cyclical permutation of the V1 loop of JRFL in order to develop better gp120 trimers to elicit neutralizing antibodies. Some mutated trimers showed improved binding to several mAbs, including VRC01, VRC03, VRC-PG04, PGT128, PGT145, PGDM1400, b6, and F105. Guinea pigs immunized with prospective trimers showed improved neutralization of a panel of HIV-1 pseudoviruses. Binding of VRC01 to JRFL was abolished by mutation N279A. Kesavardhana2017 (vaccine antigen design, vaccine-induced immune responses)
VRC01: This study investigated the ability of native, membrane-expressed JR-FL Env trimers to elicit NAbs. Rabbits were immunized with virus-like particles (VLPs) expressing trimers (trimer VLP sera) and DNA expressing native Env trimer, followed by a protein boost (DNA trimer sera). N197 glycan- and residue 230- removal conferred sensitivity to Trimer VLP sera and DNA trimer sera respectively, showing for the first time that strain-specific holes in the "glycan fence" can allow the development of tier 2 NAbs to native spikes. All 3 sera neutralized via quaternary epitopes and exploited natural gaps in the glycan defenses of the second conserved region of JR-FL gp120. VRC01 was 1 of 4 reference VRC01-like bNAbs - VRC01, 3BNC117, 8ANC131, CH103. Crooks2015 (glycosylation, neutralization)
VRC01: 24 participants received VRC01 as immunotherapy during ART treatment interruption. VRC01 delayed viral rebound by approximately 4 to 6 weeks. VRC01 exerted pressure on the rebounding virus, resulting in selection for neutralization-resistant viruses. Bar2016 (immunotherapy)
VRC01: Env residue N197 on the BG505-SOSIP trimer was mutated to test the effect of its glycosylation on the binding kinetics of CD4BS and other mAbs. Removal of the glycan had little effect on the overall structure of the molecule. Its removal resulted in increased binding of CD4 and CD4BS antibodies (VRC01, VRC03, V3-3074), but little effect on bNAbs targeting other epitopes (PG9, PG16, PGT145, 17b, A32, 2G12, PGT121, PGT126). Two CD4BS-binding antibodies tested (b12, F105) had insufficient breadth to bind the BG505-SOSIP trimer. Removal of the N197 glycan may allow for the development of better SOSIP immunogens, particularly to elicit CD4BS-specific Abs. Liang2016 (glycosylation, vaccine antigen design)
VRC01: Chimeric antigen receptors, i.e., fusion proteins made from single-chain antibodies, may be a useful approach to immunotherapy. A set of mAbs were chosen based on their binding to a variety of sites on Env and availability of antibody sequences. The chimeric receptors were created by fusing the antibody's heavy chain, light chain, and two signaling domains into a single molecule. All 7 antibodies used to make the chimeric receptors (10E8, 3BNC117, PGT126, VRC01, X5, PGT128, PG9) showed specific killing of HIV-1 infected cells and suppression of viral replication against a panel of HIV-1 strains. Ali2016 (immunotherapy, chimeric antibody)
VRC01: This review classified and mapped the binding regions of 32 bNAbs isolated 2010-2016. Wu2016 (review)
VRC01: In neutralization assays of antibody mixtures, there was a modest synergy between the CD4bs VRC01 and either of the two CD4i MAbs E51 and 412d. The synergy is likely the result of the ability of CD4i antibodies (E51 or 412d) to induce the open state and facilitate access to the CD4 binding site. The presence of E51 enhanced the Env binding of VRC01, NIH45-46, NIH45-46^G54W, and to a lesser extent 3BNC117. Gardner2016 (antibody interactions)
VRC01: This study produced Env SOSIP trimers for clades A (strain BG505), B (strain JR-FL), and G (strain X1193). Based on simulations, the MAb-trimer structures of all MAbs tested needed to accommodate at least one glycan, including both antibodies known to require specific glycans (PG9, PGT121, PGT135, 8ANC195, 35O22) and those that bind the CD4-binding site (b12, CH103, HJ16, VRC01, VRC13). A subset of monoclonal antibodies bound to glycan arrays assayed on glass slides (VRC26.09, PGT121, 2G12, PGT128, VRC13, PGT151, 35O22), while most of the antibodies did not have affinity for oligosaccharide in the context of a glycan array (PG9, PGT145, PGDM1400, PGT135, b12, CH103, HJ16, VRC16, VRC01, VRC-PG04, VRC-CH31, VRC-PG20, 3BNC60, 12A12, VRC18b, VRC23, VRC27, 1B2530, 8ANC131, 8ANC134, 8ANC195). Stewart-Jones2016 (antibody binding site, glycosylation, structure)
VRC01: This study assessed the ADCC activity of antibodies of varied binding types, including CD4bs (b6, b12, VRC01, PGV04, 3BNC117), V2 (PG9, PG16), V3 (PGT126, PGT121, 10-1074), oligomannose (2G12), MPER (2F5, 4E10, 10E8), CD4i (17b, X5), C1/C5 (A32, C11), cluster I (240D, F240), and cluster II (98-6, 126-7). ADCC activity was correlated with binding to Env on the surfaces of virus-infected cells. ADCC was correlated with neutralization, but not always for lab-adapted viruses such as HIV-1 NLA-3. vonBredow2016 (ADCC)
VRC01: This review summarizes representative anti-HIV MAbs of the first generation (2G12, b12, 2F5, 4E10) and second generation (PG9, PG16, PGT145, VRC26.09, PGDM1400, PGT121, PGT124, PGT128, PGT135, 10-1074, VRC01, 3BNC117, CH103, PGT151, 35O22, 8ANC195, 10E8). Structures, epitopes, VDJ usage, CDR usage, and degree of somatic hypermutation are compared among these antibodies. The use of SOSIP trimers as immunogens to elicit B-cell responses is discussed. Burton2016 (review, structure)
VRC01: This study estimated intra-lineage longitudinal evolutionary rate changes for the VRC26 and CH103 lineages and compared these to the reported rate changes of the VRC01 lineage. Results confirmed that a decreasing evolutionary rate is common to all three lineages. Sheng2016 (antibody lineage)
VRC01: Two stable homogenous gp140 Env trimer spikes, Clade A 92UG037.8 Env and Clade C C97ZA012 Env, were identified. 293T cells stably transfected with either presented fully functional surface timers, 50% of which were uncleaved. A panel of neutralizing and non-neutralizing Abs were tested for binding to the trimers. Consistent with CD4bs bNAbs, VRC01 bound cell surface tightly whether the trimer contained its C-terminal or not, and was competed out by sCD4. It was able to neutralize the 92UG037.8 HIV-1 isolate. Chen2015 (neutralization, binding affinity)
VRC01: Factors that independently affect bNAb induction and evolution were identified as viral load, length of untreated infection and viral diversity. Ethnically, black subjects induced bNAbs more than white subjects, but this did not correlate with type of Ab response. Fingerprint analyses of induced bNAbs showed strong subtype-dependency, with subtype B inducing significantly higher levels of CD4bs Abs and non-subtype B inducing V2-glycan specific Abs. Of the 239 bNAb antibody inducers found from 4,484 HIV-1 infected subjects,the top 105 inducers' neutralization fingerprint and epitope specificity was determined by comparison to the following antibodies - PG9, PG16, PGDM1400, PGT145 (V2 glycan); PGT121, PGT128, PGT130 (V3 glycan); VRC01, PGV04 (CD4bs) and PGT151 (interface) and 2F5, 4E10, 10E8 (MPER). Rusert2016 (neutralization, broad neutralizer)
VRC01: PGT145 was used to positively isolate a subtype B Env trimer immunogen, B41 SOSIP.664-D7324, that exists in two conformations, closed and partially open. bNAbs tested against the trimer were able to neutralize the B41 pseudovirus with a wide range of potencies. All tested non-NAbs did not neutralize B41 (IC₅₀ >50µg/ml). CD4bs bNAb, VRC01, was able to neutralize and bind B41 pseudovirus and trimer well. Pugach2015
VRC01: The first generation of HIV trimer soluble immunogens, BG505 SOSIP.664 were tested in a mouse model for generation of nAb to neutralization-resistant circulating HIV strains. No such NAbs were induced, as mouse Abs targeted the bottom of soluble Env trimers, suggesting that the glycan shield of Env trimers is impenetrable to murine B cell receptors and that epitopes at the trimer base should be obscured in immunogen design in order to avoid non-nAb responses. Association and dissociation of known anti-trimer bNAbs (VRC01, PGT121, PGT128, PGT151, PGT135, PG9, 35O22, 3BC315 and PGT145) were found to be far greater than murine generated non-NAbs. Hu2015
VRC01: A comprehensive antigenic map of the cleaved trimer BG505 SOSIP.664 was made by bNAb cross-competition. Epitope clusters at the CD4bs, quaternary V1/V2 glycan, N332-oligomannose patch and new gp120-gp41 interface and their interactions were delineated. Epitope overlap, proximal steric inhibition, allosteric inhibition or reorientation of glycans were seen in Ab cross-competition. Thus bNAb binding to trimers can affect surfaces beyond their epitopes. Among CD4bs binding bNAbs, VRC01 recognizes trimer similarly to CH103, CH106, 3BNC117 and 1NC9, and is inhibited by sCD4. VRC01 enhanced binding of non-NAb 17b. outer domain (OD)-glycan bNAbs, PGT135 and PGT136, though ˜ 5x less efficient binders of trimer, were able to unidirectionally inhibit binding of VRC01, as also other CD4bs bNAbs, 3BNC117, 2BNC60, NIH45-46. Derking2015 (antibody interactions, neutralization, binding affinity, structure)
VRC01: Two clade C recombinant Env glycoprotein trimers, DU422 and ZM197M, with native-like structural and antigenic properties involving epitopes for all known classes of bNAbs, were produced and characterized. These Clade C trimers (10-15% of which are in a partially open form) were more like B41 Clade B trimers which have 50-75% trimers in the partially open configuration than like B505 Clade B trimers, almost 100% in the closed, prefusion state. The Clade C trimer ZM197M is strongly reactive to the CD4bs bNAb VRC01 but trimer DU442 and its pseudotyped virus are weakly reactive with VRC01. The structure of a complex of ZM197M SOSIP.664 with VRC01 Fab at 9.6 A by cryo-EM had a 0.96 correlation with the structure of the Clade A trimer. Julien2015 (assay or method development, structure)
VRC01: Env trimer BG505 SOSIP.664 as well as the clade B trimer B41 SOSIP.664 were stabilized using a bifunctional aldehyde (glutaraldehye, GLA) or a heterobifunctional cross-linker, EDC/NHS with modest effects on antigenicity and barely any on biochemistry or structural morphology. ELISA, DSC and SPR were used to test recognition of the trimers by bNAbs, which was preserved and by weakly NAbs or non-NAbs, which was reduced. Cross-linking partially preserves quaternary morphology so that affinity chromatography by positive selection using quaternary epitope-specific bNAabs, and negative selection using non-NAbs, enriched antigenic characteristics of the trimers. Binding of the anti-CD4bs bNAb VRC01 to trimers was minimally affected by trimer cross-linking. Schiffner2016 (assay or method development, binding affinity, structure)
VRC01: HIV-1 escape from the N332-glycan dependent bNAb, PGT135, developed in an elite controller but without change to the PGT135-binding Env epitope itself. Instead an insertion increasing V1 length by up to 21 residues concomitant with an additional 1-3 glycans and 2-4 cysteines shields the epitope from PGT135. The majority of viruses tested developed a 14-fold resistance to PGT135 from month 7 to 11. In contrast no significant difference in neutralization sensitivity was seen between HIV-1 and bNAb VRC01. vandenKerkhof2016 (elite controllers, neutralization, escape)
VRC01: The native-like, engineered trimer BG505 SOSIP.664 induced potent NAbs against conformational epitopes of neutralization-resistant Tier-2 viruses in rabbits and macaques, but induced cross-reactive NAbs against linear V3 epitopes of neutralization-sensitive Tier-1 viruses. A different trimer, B41 SOSIP.664 also induced strong autologous Tier-2 NAb responses in rabbits. Sera from 10/20 BG505 SOSIP.664-D7324 trimer-immunized rabbits were capable of inhibiting VRC01 binding to CD4bs, but gp140-immunized sera could not. 4/4 similarly trimer-immunized macaque sera also inhibited VRC01 binding. Serum inhibition of VRC01-trimer binding significantly correlated with rabbit autologous neutralization of the trimer-equivalent psuedovirus, BG505.T332N. Sanders2015 (antibody generation, neutralization, binding affinity, polyclonal antibodies)
VRC01: A new trimeric immunogen, BG505 SOSIP.664 gp140, was developed that bound and activated most known neutralizing antibodies but generally did not bind antibodies lacking neuralizing activity. This highly stable immunogen mimics the Env spike of subtype A transmitted/founder (T/F) HIV-1 strain, BG505. Anti-CD4bs bNAb VRC01 neutralized BG505.T332N, the pseudoviral equivalent of the immunogen BG505 SOSIP.664 gp140, and was shown to recognize and bind the immunogen too. Sanders2013 (assay or method development, neutralization, binding affinity)
VRC01: This review discusses the application of bNAbs for HIV treatment and eradication, focusing on bnAbs that target key epitopes, specifically: 2G12, 2F5, 4E10, VRC01, 3BNC117, PGT121, VRC26.08, VRC26.09, PGDM1400, and 10-1074. VRC01 was one of the first CD4bs antibodies identified, and it has been tested in both prophylactic and therapeutic human trials. Stephenson2016 (immunotherapy, review)
VRC01: This paper describes modifications that expand the germ line VRC01-class antibody-recognition potential of the previously described 426c Env. The authors show that an optimized Env immunogen can engage multiple germ line VRC01-class antibodies. McGuire2016 (antibody interactions, antibody lineage)
VRC01: This review discusses the breakthroughs in understanding of the biology of the transmitted virus, the structure and nature of its envelope trimer, vaccine-induced CD8 T cell control in primates, and host control of bnAb elicitation. Haynes2016 (review)
VRC01: This study described a natural interaction between Abs and mucin protein, especially, MUC16 that is enhanced in chronic HIV infection. Agalactosylated (G0) Abs demonstrated the highest binding to MUC16. Binding of Abs to epithelial cells was diminished following MUC16 knockdown, and the MUC16 N-linked glycans were critical for binding.These point to a novel opportunity to enrich Abs at mucosal sites by targeting Abs to MUC16 through changes in Fc glycosylation, potentially blocking viral movement. Surface plasmon resonance (SPR) was performed to determine the binding affinity of Fc, Fab, and F(ab)2 of VRC01 to MUC16. They determined the relative percentage of G0, G1, and G2 glycan structures and the enhanced MUC16 binding with VRC01 was linked to higher G0 glycosylation. Gunn2016 (antibody interactions, glycosylation)
VRC01: A panel of Env-specific mAbs was isolated from 6 HIV1-infected lactating women. Antibodies in colostrum may help prevent mucosal infection of the infant, so this study aimed to define milk IgGs for future vaccination strategies to reduce HIV transmission during lactation. Despite the high rate of VH 1-69 usage among colostrum Env specific B cells, it did not correlate with distinct gp120 epitope specificity or function. VRC01 was compared to the newly-derived mAbs; it tested positive in one assay of cross-reactivity with gut bacteria, and positive in one test of autoreactivity. Jeffries2016 (antibody polyreactivity)
VRC01: The study detailed binding kinetics of the interaction between BG505 SOSIP.664 trimer or its variants (gp120 monomer; first study of disulfide-stabilized variant gp120-gp41_ECTO protomer) and several mAbs, both neutralizing (VRC01, PGV04, PG9, PG16, PGT121, PGT122, PGT123, PGT145, PGT151, 2G12) and non-neutralizing (b6, b12, 14e, 19b, F240). CD4bs-directed VRC01 potently neutralizes BG505.T332N pseudovirus and binds strongly to all 3 antigens with slow dissociation. Yasmeen2014 (antibody binding site, assay or method development)
VRC01: Neutralization breadth in 157 antiretroviral-naive individuals infected for less than 1 year post-infection was studied and compared to a cohort of 170 untreated chronic patients. A range of neutralizing activities was observed with a panel of six recombinant viruses from five different subtypes. Some sera were broadly reactive, predominantly targeting envelope epitopes within the V2 glycan-dependent region. The Env neutralization breadth was positively associated with time post infection. VRC01 has been used as a control in testing CD4 binding site neutralizing specificity of the sera. Sanchez-Merino2016 (neutralization, acute/early infection)
VRC01: This review summarized the novel strategies for HIV vaccine discovery. Multiple therapeutic vaccines have failed in the past, in a non placebo controlled trial, a Tat vaccine demonstrated immune cell restoration, reduction of immune activation, and reduced HIV-1 DNA viral load. bNAbs offer both prevention potential and treatment. In early-phase clinical trials, VRC01 reduced viral load in HIV-1-infected individuals not on HAART. Gray2016 (vaccine antigen design, vaccine-induced immune responses, HAART, ART, review)
VRC01: A new, current, mostly tier2 panel of 200 C-clade Env-psuedotyped viruses from early (< 100d) infection in southern Africa was used to assess antibody responses to natural infection and to vaccines. Viruses were assayed with bNAbs targeting the V2 glycan (PG9, VRC26.25), the MPER site (4E10), the CD4 binding site (VRC01), and the V3/C3 glycan site (PGT128). For VRC01 (and all other Abs besides PGT128) there was no significant difference in neutralization between pre-seroconversion and post-seroconversion viruses. When viruses from 3 time periods were compared, breadth remained constant, but potency decreased, indicating that the C clade epidemic is becoming increasingly resistant to VRC01. Viruses collected pre-seroconversion were more resistant to neutralization by serum than those post-seroconversion. As the epidemic matured over 13 years, viruses also became more resistant to mAbs tested. Rademeyer2016 (assay or method development, neutralization)
VRC01: Ten mAbs were isolated from a vertically-infected infant BF520 at 15 months of age. Ab BF520.1 neutralized pseudoviruses from clades A, B and C with a breadth of 58%, putting it in the same range as second-generation bNAbs derived from adults, but its potency was lower. BF520.1 was shown to target the base of the V3 loop at the N332 supersite. CD4 bs-binding, second-generation mAb, VRC01 when compared had a geometric mean of IC₅₀=2.13 µg/ml for 11/12 viruses it neutralized at a potency of 92%. The infant-derived antibodies had a lower rate of somatic hypermutation (SHM) and no indels compared to adult-derived anti-V3 mAbs. This study shows that bnAbs can develop without SHM or prolonged affinity maturation. Simonich2016 (neutralization, structure)
VRC01: This study examined the neutralization of group N, O, and P primary isolates of HIV-1 by diverse antibodies. Cross-group neutralization was observed only with the bNAbs targeting the N160 glycan-V1/V2 site. Four group O isolates, 1 group N isolate, and the group P isolates were neutralized by PG9 and/or PG16 or PGT145 at low concentrations. None of the non-M primary isolates were neutralized by bNAbs targeting other regions, except 10E8, which weakly neutralized 2 group N isolates, and 35O22 which neutralized 1 group O isolate. Bispecific bNAbs (PG9-iMab and PG16-iMab) very efficiently neutralized all non-M isolates with IC₅₀ below 1 ug/mL, except for 2 group O strains. Anti-CD4bs bNAb VRC01 was able to neutralize only 1/16 tested non-M primary isolates at an IC₅₀< 10µg/ml, RBF208,M/O at 3.64 µg/ml. Morgand2015 (neutralization, subtype comparisons)
VRC01: The neutralization of 14 bnAbs was assayed against a global panel of 12 or 17 Env pseudoviruses. From IC₅₀, IC₈₀, IC₉₀, and IC₉₉ values, the slope of the dose-response curve was calculated. Each class of Ab had a fairly consistent slope. Neutralization breadth was strongly correlated with slope. An IIP (Instantaneous Inhibitory Potential) value was calculated, based on both the slope and IC50, and this value may be predictive of clinical efficacy. VRC01, a CD4bs bnAb belonged to a group with slopes >1. Webb2015 (neutralization)
VRC01: This study evaluated the binding of 15 inferred germline (gl) precursors of bNAbs that are directed to different epitope clusters, to 3 soluble native-like SOSIP.664 Env trimers - BG505, B41 and ZM197M. The trimers bound to some gl precursors, particularly those of V1V2-targeted Abs. These trimers may be useful for designing immunogens able to target gl precursors. CD4bs-binding gl-VRC01 precursor did not bind to any trimers. Sliepen2015 (binding affinity, antibody lineage)
VRC01: This study presented structures of germline-reverted VRC01-class bNAbs alone and complexed with 426c-based gp120 immunogens. Germline bNAb–426c gp120 complexes showed preservation of VRC01-class signature residues and gp120 contacts, but detectably different binding modes compared to mature bNAb-gp120 complexes. It reported that unlike most antibodies, the overall final structures of VRC01 class antibodies are formed before the antibodies mature. NIH45-46GL and 3BNC60GL make all predicted HC VRC01-class signature contacts with the CD4-binding loop, the V5 loop, and loop D to bind to gp120. Scharf2016 (structure)
VRC01: This study reported that early passive immunotherapy can eliminate early viral foci and thereby prevent the establishment of viral reservoirs. HIV-1–specific human neutralizing mAbs (NmAbs) were used as a post-exposure therapy in an infant macaque model for intrapartum MTCT, inoculated orally with the SHIV SF162P3. On days 1, 4, 7 and 10 post virus exposure, animals were injected with NmAbs and quantified systemic distribution 24 h after Ab administration. Replicating virus was found in multiple tissues by day 1 in untreated animals. For VRC01 The time to maximal concentration in the plasma was 24 h, independent of dose, and the serum (plasma) half-life of VRC01 was 3.9–4.2 d. All NmAb-treated macaques were free of virus in blood and tissues at 6 months after exposure. Hessell2016 (neutralization, acute/early infection, immunotherapy, mother-to-infant transmission)
VRC01: Donor EB179 was a long-term non-progressor with high serum neutralization breadth and potency. 8 B-cell clones produced Abs, including 179NC75 which had the highest neutralization, especially to Clade B virus, neutralizing 70% of a clade-B pseudovirus panel and 6 out of 9 cross-clade Env pseudoviruses as opposed to bNAb VRC01's neutralizing 7/9 of the same psuedoviral panel. 179NC75 was also more potent than VRC01 against 8 viruses of a 22 Tier-2 clade B panel. Freund2015 (neutralization, broad neutralizer)
VRC01: A panel of antibodies was tested for binding, stability, and ADCC activity on HIV-infected cells. The differences in killing efficiency were linked to changes in binding of the antibody and the accessibility of the Fc region when bound to infected cells. Ab VRC01 had weak ADCC. Bruel2016 (ADCC, binding affinity)
VRC01: This review discusses the structural characteristics of bNAbs, how they recognize the virus, and new vaccination strategies that aim to guide B cells to produce protective Abs. The evolutionary lineage of VRC01 in the donor has been extensively studied. Although VRC01 had a 5-fold lower mutation rate than other bNAbs, such as CA256-VRC26 and CH103, it seems likely that the principles that guide VRC01 bNAb development will apply to other bNAb ontogenies. Sadanand2016 (vaccine antigen design, review)
VRC01: To test whether NAbs can inhibit viral transmission through mucosal tissue, 4 bNAbs (PG9, PG16, VRC01, 4E10) were tested in tissue culture models of human colonic and ectocervical tissues. All 4 nAbs reduced HIV transmission, with a relative efficacy of PG16 > PG9 > VRC01 >> 4E10. The nAbs had a good safety profile and were not affected by the presence of semen. Scott2015 (immunotherapy)
VRC01: The study's goal was to produce modified SOSIP trimers that would reduce the exposure - and, by inference, the immunogenicity - of non-NAb epitopes such as V3. The binding of several modified SOSIP trimers was compared among 12 neutralizing (PG9, PG16, PGT145, PGT121, PGT126, 2G12, PGT135, VRC01, CH103, CD4, IgG2, PGT151, 35O22) and 3 non-neutralizing antibodies (14e, 19b, b6). The V3 non-NAbs 447-52D, 39F, 14e, and 19b bound less well to all A316W variant trimers compared to wild-type trimers. Mice and rabbits immunized with modified, stabilized SOSIP trimers developed fewer V3 Ab responses than those immunized with native trimers. deTaeye2015 (antibody binding site)
VRC01: In 5 years additional members of the CH235 clonal lineage were isolated based on deep sequencing of donor CH505's V_L and V_H chains at 17 timepoints in the donor's infection. Two of these had greater neutralization potency, CH235.9 and CH235.12. Study of crystal structures indicated a site of vulnerability near the Env CD4 binding site. The lineages of CH103 and CH235, both derived from Donor CH505 were compared - CH103 lineage K_d increased an order of magnitude each step of maturation but maintained a fast association rate; CH235 lineage however, had slower K_ds and K_as over maturation. VRC01 was used as a control and neutralized 89% of a 202-multiclade Env-psuedovirus panel at a potency of <50 µg/ml. Despite using VH1-46, the CH235.9 and CH235.12 neutralizing profiles were more similar functionally to that of VH1-2-derived antibody VRC01. Structurally, both VRC01 and the CH235 bNAbs mimic CD4 to bind virus, preserving contacts with gp120 D368. Bonsignori2016 (neutralization, binding affinity, antibody sequence)
VRC01: A germline-targeting immunogen (eOD-GT8) was developed to elicit VRC01-class bNAbs. HIV-naive humans were shown to have VRC01-class precursor naive B cells that responded to this immunogen. Not only are the eOD-GT8 isolated naïve B cells highly enriched for VRC01-class core characteristics of VH1-02 and a 5–amino acid L-CDR3, they possess further refined sequence attributes of VRC01-class bNAbs. Jardine2016 (vaccine antigen design, immunotherapy, antibody lineage)
VRC01: HIV-1 strains were isolated from 60 patients infected with CRFs 01_AE, 07_BC, and 08_BC. Eight CRF01 strains that produced high-titer Env pseudoviruses were studied further. All were sensitive to neutralization by VRC01, PG9, PG16, and NIH45-46, but insensitive to 2G12. Mutations in either of the loop D or V5 regions (or both) may be critical for natural evasion of VRC01. However, the resistance mechanisms are currently unknown and four CRF01 AE viruses, CNAE08, CNAE14, CNAE17, and CNAE31, were demonstrated to be resistant to VRC01. Exchanging the V5 region alone did not affect the sensitivity of the viruses to VRC01.CNAE09, CNAE10, and CNAE11 strains containing the asparagine residue at position 461 were still highly sensitive to VRC01. CNAE17 demonstrated the highest levels of resistance may be due to the presence of mutation S365P in the CD4bs. Chen2016 (neutralization, subtype comparisons)
VRC01: Four bNAbs (VRC01, VRC01-LS, 3BNC117, and 10-1074) were administered, singly or in combination, to macaques, followed by weekly challenges with clade B SHIV_AD8. In all cases, the administration of MAbs delayed virus acquisition. Control animals required 2 to 6 challenges before becoming infected, while animals receiving VRC01 required 4–12 challenges; 3BNC117 required 7–20 challenges; 10-1074 required 6–23 challenges; and VRC01-LS required 9–18 challenges. Animals that received a single antibody infusion resisted infection for up to 23 weekly challenges. Gautam2016 (immunotherapy)
VRC01: A large cross-sectional study of sera from 205 ART-naive patients infected with different HIV clades was tested against a panel of 219 cross-clade Env-pseudotyped viruses. Their neutralization was compared to the neutralization of 10 human bNAbs (10E8, 4E10, VRC01, PG9, PGT145, PGT128, 2F5, CH01, b12, 2G12) tested with a panel of 119 Env-pseudotyped viruses. Results from b12 and 2G12 suggested that these bnAbs may not be as broadly neutralizing as previously thought. VRC01 neutralized 89% of the 199 viruses tested. Hraber2014 (neutralization)
VRC01: This study isolated 4 novel antibodies that bind the CD4 binding site of Env. Population-level analysis classified a diverse group of CD4bs antibodies into two types: CDR H3-dominated or VH-gene-restricted, each with distinct ontogenies. Structural data revealed that neutralization breadth was correlated with angle of approach of the antibodies to the CD4 binding region. VRC01 was one of the antibodies in the VH-gene-restricted class. Zhou2015 (neutralization, structure, antibody lineage, broad neutralizer)
VRC01: Double, triple or quadruple combinations of fifteen bNAbs that target 4 distinct epitope regions: the CD4 binding site (3BNC117, VRC01, VRC07, VRC07-523, VRC13), the V3-glycan supersite (10–1074, 10-1074V, PGT121, PGT128), the V1/V2-glycan site (PG9, PGT145, PGDM1400, CAP256-VRC26.08, CAP256-VRC26.25), and the gp41 MPER epitope (10E8) were studied. Their neutralization potency and breadth were assayed against a panel of 200 acute/early subtype C strains, and compared to a novel, highly accurate predictive mathematical model (no-overlap Bliss Hill model, CombiNaber tool, LANL HIV Immunology database). These data were used to predict the best combinations of bNAbs for immunotherapy. Wagh2016 (neutralization, immunotherapy)
VRC01: VRC07-523:BNabs were tested for their ability to suppress viremia during acute infection in rhesus macaques. Most effective by all virological parameters was dual therapy with VRC07-523 + PGT121. Therapy with VRC01 also curtailed viral replication, but less consistently. These finding support the use of MAbs for immunotherapy during early infection. Bolton2015 (acute/early infection, immunotherapy)
VRC01: The rate of maturation and extent of diversity for the VRC01 lineage were characterized through longitudinal sampling of peripheral B cell transcripts from donor 45 over 15 years and co-crystal structures. VRC01-lineage clades underwent continuous evolution, with rates of ˜2 substitutions per 100 nucleotides per year, comparable with HIV-1 evolution. 39 VRC01-lineage Abs segregated into three major clades, and all Abs from donor 45 contained a cysteine at position 98 (99 in some sequences due to a 1-aa insertion) which was used as a signature to assess membership in the VRC01 lineage. Of 1,041 curated NGS sequences assigned to the VRC01 lineage, six did not contain the cysteine while 1,035 did (99.4%). For this Ab CDR H3 length is 12 and VH changes 32%, Vk nucleotide change is 18%. Wu2015 (antibody lineage)
VRC01: A VRC01 drug product was administered to 23 participants: 15 were on ART, and 8 were viremic and not receiving ART. The treatment reduced viremia significantly only in the viremic subjects. In 4 of these subjects, the reduction in viremia was accompanied by outgrowth of viruses that were less neutralization-sensitive. Lynch2015 (immunotherapy)
VRC01: CD4-binding site Abs are reviewed. New insights from donor-serum responses, atomic-level structures of antibody-Env complexes, and next-generation sequencing of B-cell transcripts are invigorating vaccine-design efforts to elicit effective CD4-binding site Abs. Analysis of the epitopes recognized by CD4-binding Abs reveals substantial similarity in the recognized region of gp120. VRC01 targets the outer domain of gp120. Georgiev2013a (review)
VRC01: The human Ab gene repertoires of uninfected and HIV-1-infected individuals were studied at genomic DNA (gDNA) and cDNA levels to determine the frequencies of putative germline Ab genes of known HIV-1 bnAbs. All libraries were deep sequenced and analysed using IMGT/HighV-QUEST software (http://imgt.org/HighV-QUEST/index. The human gDNA Ab libraries were more diverse in heavy and light chain V-gene lineage usage than the cDNA libraries. This implied that the human gDNA Ab gene repertoires may have more potential than the cDNA repertoires to develop HIV-1 bnmAbs. Relatively high frequencies of the VH and VKs and VLs that used the same V-genes and had the same CDR3 lengths as known HIV-1 bnmAbs regardless of (D)J-gene usage. The putative germline genes were determined for a set of mAbs (b12, VRC01, VRC03, NIH45-46, 3BNC60, PG9, PGT127, and X5). Zhang2013 (antibody lineage, germline)
VRC01: A previous study demonstrated the presence of VRC01-resistant strains in an HIV-1 infected patient during antiretroviral therapy. This study report follow-up of two subsequent samples, CRF08-BC env clones,CNE47 and CNE48 from the same patient. With genetic and phenotypic analysis it showed that VRC01-resistant HIV-1 continued to exist and the resistant phenotype was associated with a single asparagine residue at position 460 (N460), a potential N-linked glycosylation site in the V5 region. Guo2014
VRC01: A subset of bNAbs that inhibit both cell-free and cell-mediated infection in primary CD4+ lymphocytes have been identified. These antibodies target either the CD4-binding site or the glycan/V3 loop on HIV-1 gp120 and act at low concentrations by inhibiting multiple steps of viral cell to cell transmission. This property of blocking viral transmission to plasmacytoid DCs and interfering with type-I IFN production should be considered an important characteristic defining the potency for therapeutic or prophylactic antiviral strategies. VRC01 was only partially effective in blocking cell to cell transmission. Malbec2013
VRC01: The effect of PNGS on viral infectivity and antibody neutralization (2F5, 4E10, b12, VRC01, VRC03, PG9, PG16, 3869) was evaluated through systemic mutations of each PNGS on CRF07_BC strain. Mutations at N197 (C2), N301 (V3), N442 (C4), and N625 (gp41) rendered the virus more susceptible to neutralization by MAbs that recognize the CD4 binding site or gp41. Generally, mutations on V4/V5 loops, C2/C3/C4 regions, and gp41 reduced the neutralization sensitivity to PG16. However, mutation of N289 (C2) made the virus more sensitive to both PG9 and PG16. Mutations at N142 (V1), N355 (C3) and N463 (V5) conferred resistance to neutralization by anti-gp41 MAbs. Available structural information of HIV Env and homology modeling was used to provide a structural basis for the observed biological effects of these mutations. Wang2013 (neutralization, structure)
VRC01: This review surveyed the Vectored Immuno Prophylaxis (VIP) strategy, which involves passive immunization by viral vector-mediated delivery of genes encoding bnAbs for in vivo expression. Recently published studies in humanized mice and macaques were discussed as well as the pros and cons of VIP towards clinical applications to control HIV endemics. A single injection of AAV8 vector achieved peak Ab production in serum at week 6.VRC01 could provide full protection against HIV challenge (10 ng) at a titer of 8.3 μg/mL conforming the superiority over b12. Yang2014 (immunoprophylaxis, review, antibody gene transfer)
VRC01: Engineered nanoparticle immunogens eOD-GT8 in 60mer and 3mer form bound VRC01 bNAb precursors and induced VRC01-class bNAbs with classic short CDRL3 in a VRC01 gH (approximated germline-reverted heavy chain precursor) knock-in mouse. Induced antibodies had mutations favoring binding to near-native gp120 constructs. Jardine2015 (antibody generation, enhancing activity, broad neutralizer)
VRC01: The ability of bNAbs to inhibit the HIV cell entry was tested for b12, VRC01,VRC03, PG9, PG16, PGT121, 2F5, 10E8, 2G12. Among them, PGT121, VRC01, and VRC03 potently inhibited HIV entry into CD4+ T cells of infected individuals whose viremia was suppressed by ART. Chun2014 (immunotherapy)
VRC01: The heavy and light chains of VRC01 were stably expressed in tobacco plant cells. The resulting antibody had neutralization breadth and potency similar to that produced in HEK cells. The results demonstrate a method for low-cost production of anti-HIV antibodies. Teh2014 (antibody gene transfer)
VRC01: A gp140 trimer mosaic construct (MosM) was produced based on M group sequences. MosM bound to CD4 as well as multiple bNAbs, including VRC01, 3BNC117, PGT121, PGT126, PGT145, PG9 and PG16. The immunogenicity of this construct, both alone and mixed together with a clade C Env protein vaccine, suggest a promising approach for improving NAb responses. Nkolola2014 (vaccine antigen design)
VRC01: Cross-group neutralization of HIV-1 isolates from groups M, N, O, and P was tested with diverse patient sera and bNAbs PG9, PG16, 4E10, b12, 2F5, 2G12, VRC01, VRC03, and HJ16. The primary isolates displayed a wide spectrum of sensitivity to neutralization by the human sera, with some cross-group neutralization clearly observed. Among the bNAbs, only PG9 and PG16 showed any cross-group neutralization. The group N prototype strain YBF30 was highly sensitive to neutralization by PG9, and the interaction between their key residues was confirmed by molecular modeling. The conservation of the PG9/PG16 epitope within groups M and N suggests its relevance as a vaccine immunogen. Braibant2013 (neutralization, variant cross-reactivity)
VRC01: VRC01 was one of 10 MAbs used to study chronic vs. consensus vs. transmitted/founder (T/F) gp41 Envs for immunogenicity. Consensus Envs were the most potent eliciters of response but could only neutralize tier 1 and some tier 2 viruses. T/F Envs elicited the greatest breadth of NAb response; and chronic Envs elicited the lowest level and narrowest response. This CD4BS binding Nab bound well at <10 nM to 3/5 chronic Envs, 4/6 Consensus Envs and 6/7 T/F Envs. Liao2013c (antibody interactions, binding affinity)
VRC01: Study evaluated 4 gp140 Env protein vaccine immunogens derived from an elite neutralizer donor VC10042, an HIV+ African American male from Vanderbilt cohort. Env immunogens, VC10042.05, VC10042.05RM, VC10042.08 and VC10042.ela, elicited high titers of cross-reactive Abs recognizing V1/V2 regions. All the Env protein except VC10042.05 bound to VRC01, although weak binding was detected with VC10042.05 monomer. Parental Env of VC10042.ela was highly neutralized by VRC01. Carbonetti2014 (elite controllers, vaccine-induced immune responses)
VRC01: The effect of low pH and HIV-1 Abs which increased the transcytosis of the virus by 20 fold, has been reported. This enhanced transcytosis was due to the Fc neonatal receptor (FcRn), which facilitates HIV-1's own transmission by usurping Ab responses directed against itself. Both infectious and noninfectious viruses were transcytosed by VRC01. Gupta2013
VRC01: A set of potent VRC01-like (PVL) MAbs were generated from VRC01-derivatve NIH45-46^G54W and they were more potent than even NIH45-46 or NIH45-46^G54W, cross-recognizing viruses across clades. The novel antibodies designed based on crystal structure were NIH45-46m2, NIH45-46m7, NIH45-46m25 and NIH45-46m28, with NIH45-46m2 being the single most broad and potent antibody till date. 45-46m2 and 45-46m7 in combination with each other and a third antibody were able to thwart viral escape routes. Diskin2013
VRC01: Clade A Env sequence, BG505, was identified to bind to bNAbs representative of most of the known NAb classes. This sequence is the best natural sequence match (73%) to the MRCA sequence from 19 Env sequences derived from PG9 and PG16 MAbs' donor. A point mutation at position L111A of BG505 enabled more efficient production of a stable gp120 monomer, preserving the major neutralization epitopes. The antisera produced by this adjuvanted formulation of gp120 competed with bnAbs from 3 classes of non-overlapping epitopes. VRC01 showed very high neutralization titer against BG505 pseudovirus in a competitive binding assay as shown in Table 1. Hoffenberg2013 (antibody interactions, neutralization)
VRC01: This study evaluated the frequency of anti-gp120 B cells in follicular (FO) and marginal zone (MZ) B cells compartments of naive WT mice and human populations. Mouse MZ B cells use IGHV1-53, closely related to human IGHV1-2*02 that encodes VRC01, to generate gp120-specific Abs. VRC01 bound very well to RSC3, but IGHV1-53 didn't. These MZ B cell derived germline Abs showed similarity to purported VRC01 germline and are not protective against HIV. Pujanauski2013 (antibody lineage)
VRC01: 4 new variants of VRC07, a MAb from the VRC01 class of neutralizing antibodies were generated using structure-guided optimization and were between 4 and 5.7 times more potent than VRC01. Rudicell2014
VRC01: The neutralization profile of 1F7, a human CD4bs mAb, is reported and compared to other bnNAbs. 1F7 exhibited extreme potency against primary HIV-1, but limited breadth across clades.VRC01 neutralized 92% of a cross-clade panel of 157 HIV-1 isolates (Fig. S1) while 1F7 neutralized only 20% of the isolates. Gach2013 (neutralization)
VRC01: This study reports the development of a new cell-line (A3R5)-based highly sensitive Ab detection assay. This T-lymphoblastoid cell-line stably expreses CCR5 and recognizes CCR5-tropic circulating strains of HIV-1. A3R5 cells showed greater neutralization potency compared to the current cell-line of choice TZM-bl. VRC01 was used as a reference Ab in neutralization assay comparing A3R5 and TZM-bl. McLinden2013 (assay or method development)
VRC01: This is a review of identified bNAbs, including the ontogeny of B cells that give rise to these antibodies. Breadth and magnitude of neutralization, unique features and similar bNAbs are listed. VRC01 is a CD4bs Ab, with breadth 87%, IC₅₀ 0.98 μg per ml, and its unique feature is CD4 mimicry by its VH1-2-derived heavy chain. Similar MAbs include VRC02, VRC03, NIH45-46, 3BNC60, BNC62, 3BNC117, 12A12, 12A21, 12A30, VRC-PG04, VRC-CH31. Kwong2013 (review)
VRC01: A highly conserved mechanism of exposure of ADCC epitopes on Env is reported, showing that binding of Env and CD4 within the same HIV-1 infected cell effectively exposes these epitopes. The mechanism might explain the evolutionary advantage of downregulation of cell surface CD4v by the Vpu and Nef proteins. VRC01 was used in CD4 coexpression and competitive binding assay. Veillette2014 (ADCC)
VRC01: The ability of MAb A32 to recognize HIV-1 Env expressed on the surface of infected CD4(+) T cells as well as its ability to mediate antibody-dependent cellular cytotoxicity (ADCC) activity was investigated. This study demonstrates that the epitope defined by MAb A32 is a major target on gp120 for plasma ADCC activity. VRC01 was used as a control and A32 showed >3 fold higher ADCC activity than VRC01. Ferrari2011a (ADCC)
VRC01_d45: The ontogeny of VRC01 class Abs was determined by enumerating VRC01-class characteristics in many donors by next-gen sequencing and X-ray crystallography. Analysis included VRC01 (donor NIH 45), VRC-PG04 (donor IAVI 74), VRC-CH31 (donor 0219), 3BNC117 (donor RU3), 12A21 (donor IAVI 57), and somatically related VRC-PG19,19b, 20, 20b MAbs from donor IAVI 23. Despite the sequence differences of VRC01-class Abs, exceeding 50%, Ab-gp120 cocrystal structures showed VRC01-class recognition to be remarkably similar. It is reported that glutamic acid to glutamine mutation at residue 96 decreased the binding affinity to 10 fold in VRC01. Zhou2013a (antibody sequence, structure, antibody lineage)
VRC01: Next generation sequencing was applied to a new donor C38 (different from donor NIH45) to identify VRC01 class bNAbs. VRC01 class heavy chains were selected through a cross-donor phylogenetic analysis. VRC01 class light chains were identified through a five-amino-acid sequence motif. (CDR L3 length of 5 amino acids and Q or E at position 96 (Kabat numbering) or position 4 within the CDR L3 sequence.) Zhu2013a (antibody sequence)
VRC01: Series of VRC01 and 10E8 variants with partial framework reversions to germline in both H and L chains were created and their neutralization activity was compared to that of the mature antibody. Some of these Abs retained broad and potent neutralization activity even when their framework regions were substantially reverted back to germline, suggesting the promise of partial framework reversion for Ab optimization. Georgiev2014 (neutralization, antibody lineage)
VRC01: A statistical model selection method was used to identify a global panel of 12 reference Env clones among 219 Env-pseudotyped viruses that represent the spectrum of neutralizing activity seen with sera from 205 chronically HIV-1-infected individuals. This small final panel was also highly sensitive for detection of many of the known bNAbs, including this one. The small panel of 12 Env clones should facilitate assessments of vacine-elicited NAbs. Decamp2014 (assay or method development)
VRC01: N276D was determined as the critical binding site of MAb HJ16 by resistance induction in a sensitive primary CRF02_AG strain. N-linked glycosylation site removing N276D mutation was responsible for resistance to HJ16 by site-directed mutagenesis in envs of the homologous CRF02_AG, as well as of a subtype A and a subtype C primary isolate. Sensitivity to the CD4bs VRC01 and VRC03 mAbs was increased in the N276D mutated viruses. Balla-Jhagjhoorsingh2013 (glycosylation)
VRC01:X-ray crystallography, surface plasmon resonance and pseudovirus neutralization were used to characterize a heavy chain only llama antibody, named JM4. The full-length IgG2b version of JM4 neutralizes over 95% of circulating HIV-1 isolates. JM4 targets a hybrid epitope on gp120 that combines elements from both the CD4 binding region and the coreceptor binding surface. JM4 epitope overlaps very little with the VRC01 although the binding sites are in close proximity. JM4 IgG2b was able to potently neutralize the HIV-1 isolates that were resistant to VRC01. Acharya2013 (neutralization)
VRC01: This is a review of a satellite symposium at the AIDS Vaccine 2012 conference, focusing on antibody gene transfer. Dennis Burton showed that PGT121 provides protection in lower in vivo concentrations than b12. Balazs2013 (immunoprophylaxis)
VRC01: A computational method to predict Ab epitopes at the residue level, based on structure and neutralization panels of diverse viral strains has been described. This method was evaluated using 19 Env-Abs, including VRC01, against 181 diverse HIV-1 strains with available Ab-Ag complex structures. Chuang2013 (computational epitope prediction)
VRC01: The complexity of the epitopes recognized by ADCC responses in HIV-1 infected individuals and candidate vaccine recipients is discussed in this review. VRC01 is discussed as the CD4bs-targeting, neutralizing anti-gp120 mAb exhibiting ADCC activity and having a discontinuous epitope. Both VRC01 and b12 recognize the outer domain of gp120. b12 recognizes using Ab heavy chain, where as VRC01 uses both heavy and light chains. This differences is crucial for their neutralization breadth. Pollara2013 (ADCC, review)
VRC01: "Neutralization fingerprints" for 30 neutralizing antibodies were determined using a panel of 34 diverse HIV-1 strains. 10 antibody clusters were defined: VRC01-like, PG9-like, PGT128-like, 2F5-like, 10E8-like and separate clusters for b12, CD4, 2G12, HJ16, 8ANC195. This mAb belongs to PG9-like cluster. Georgiev2013 (neutralization)
VRC01: Cryoelectron tomography was used to determine structures of A12, m36, or m36/CD4 complexed to trimeric Env displayed on intact HIV-1 BaL virus. The steric interactions at the distal ends of the bound Ab moieties are likely to play a role in determining the rotation of gp120 as in A12 and b12 or without any quaternary structure change as in VRC01. Meyerson2013 (antibody binding site, structure)
VRC01: Systematic computational analyses of gp120 plasticity and conformational transition in complexes with CD4 binding fragments, mimetic proteins and Ab fragments is described to explain the molecular mechanisms by which gp120 interacts with the CD4bs at local and subdomain levels. An isotopic elastic network analysis, a full atomic normal mode analysis and simulation of conformational transitions were used to compare the gp120 structures in CD4 bound and Ab-bound states. VRC01 was mentioned in the context of CD4 binding sites. Korkut2012 (structure)
VRC01: This study describes an ˜11 Angstrom cryo-EM structure of the trimeric HIV-1 Env precursor in its unliganded state. The three gp120 and gp41 subunits form a cage like structure with an interior void surrounding the trimer axis which restricts Ab access. VRC01 was used in ELISA to asses the recognition of the purified Env glycoproteins and recognized conformation dependent epitopes near CD4 binding site of gp120. Mao2012 (structure)
VRC01: The sera of 20 HIV-1 patients were screened for ADCC in a novel assay measuring granzyme B (GrB) and T cell elimination and reported that complex sera mediated greater levels of ADCC than anti-HIV mAbs. The data suggested that total amount of IgG bound is an important determinant of robust ADCC which improves the vaccine potency. VRC01 was used as an anti CD4 binding Ab to study effects of Ab specificity and affinity on ADCC against HIV-1 infected targets. Smalls-Mantey2012 (ADCC, assay or method development)
VRC01: Neutralizing antibody response was studied in elite controller. Subject VC10042 is an African American male, infected with clade B for 2 decades (since 1984) without any signs of disease and no antiretroviral treatment. The neutralizing activity of autologous CD4bs NAbs was very similar to that of NIH45-46W, but very different from other anti-CD4bs MAbs tested. The viral autologous variants that were resistant to neutralization by autologous and most bnMAbs tested had an extremely rare R272/N368 combination. This mutation was shown in the study to impart a fitness cost to the virus. Sather2012 (autologous responses, elite controllers, neutralization, escape, polyclonal antibodies)
VRC01: Isolation of VRC06 and VRC06b MAbs from a slow progressor donor 45 is reported. This is the same donor from whom bnMAbs VRC01, VRC03 and NIH 45-46 were isolated and the new MAbs are clonal variants of VRC03. VRC01 was used as a broadly reactive CD4bs MAb to compare neutralizing specificity of VRC06. Li2012
VRC01: This is a comment on Tan2012. It is noted that Tran and colleagues used high-resolution 3D cryoelectron tomography to define the conformation of Env when bound to soluble CD4 and to a series of monoclonal antibodies. It was demonstrated that antibodies binding to the CD4 binding site or coreceptor binding site of Env may lead to significantly different conformations of the trimeric Env complex. VRC01 locks the complex in a closed conformation, while binding to soluble CD4 or the monoclonal antibody 17b fixed the trimer in an open conformation. Wright2012 (novel epitope)
VRC01: Previous cryo-electron tomographic studies were extended. A more complete picture of the HIV entry process was presented by showing that HIV-1 Env binding to either soluble CD4 (sCD4) or the co-receptor mimic 17b leads to the same structural opening, or activation, of the Env spike. Atudy also demonstrated structurally that the broadly neutralizing antibodies VRC01, VRC02, VRC03 are able to block this activation, locking Env in a state that resembles closed, native Env. The cryo-electron microscopic structure of soluble trimeric Env in the 17b-bound state is presented at ˜9 Å resolution, revealing it as a novel, activated intermediate conformation of trimeric Env that could serve as a new template for immunogen design. Tran2012 (structure)
VRC01: Efficacy of VRC01 as a topically administered microbicide to prevent sexual transmission was evaluated in a RAG-hu humanized mouse model of vaginal HIV-1 transmission. A combination of MAbs b12, 2F5, 4E10 and 2G12, was used as a positive efficacy control. 7/9 VRC01 antibody administered mice and all of the mice receiving the four bNAb antibody combination were protected against HIV-1 challenge. Veselinovic2012 (immunoprophylaxis)
VRC01: Two genetically related and two unrelated envelope clones, derived from CRF08_BC-infected patients, with distinct VRC01 neutralization profiles were studied, and 22 chimeric envelope clones were generated by interchanging the loop D and/or V5 regions between the original envelopes or by single alanine substitutions within each region. Interchanging the V5 region between the genetically related or unrelated clones completely swapped their VRC01 sensitivity profiles. Asn-460, a potential N-linked glycosylation site in the V5 region, was a key factor for observed resistance. The long side chain of Asn-460, and potential glycosylation, may create steric hindrance that lowers binding affinity, thereby increasing resistance to VRC01 neutralization Guo2012 (neutralization, structure)
VRC01: Neutralization profiles of 7 bnAbs were analyzed against 45 Envs (A, C, D clades), obtained soon after infection (median 59 days). The transmitted variants have distinct characteristics compared to variants from chronic patients, such as shorter variable loops and fewer potential N-linked glycosylation sites (PNGS). VRC01 neutralized 71% of these viruses. Goo2012 (neutralization, rate of progression)
VRC01: A computational tool (Antibody Database) identifying Env residues affecting antibody activity was developed. As input, the tool incorporates antibody neutralization data from large published pseudovirus panels, corresponding viral sequence data and available structural information. The model consists of a set of rules that provide an estimated IC₅₀ based on Env sequence data, and important residues are found by minimizing the difference between logarithms of actual and estimated IC₅₀. The program was validated by analysis of MAb 8ANC195, which had unknown specificity. Predicted critical N-glycosylation for 8ANC195 were confirmed in vitro and in humanized mice. The key associated residues for each MAb are summarized in the Table 1 of the paper and also in the Neutralizing Antibody Contexts & Features tool at Los Alamos Immunology Database. West2013 (glycosylation, computational epitope prediction)
VRC01: Identification of broadly neutralizing antibodies, their epitopes on the HIV-1 spike, the molecular basis for their remarkable breadth, and the B cell ontogenies of their generation and maturation are reviewed. Ontogeny and structure-based classification is presented, based on MAb binding site, type (structural mode of recognition), class (related ontogenies in separate donors) and family (clonal lineage). This MAb's classification: gp120 CD4-binding site, CD4-mimicry by heavy chain, VRC01 class, VRC01 family. Kwong2012 (review, structure, broad neutralizer)
VRC01: This review discusses the new research developments in bnAbs for HIV-1, Influenza, HCV. Models of the HIV-1 Env spike and of Influenza visrus spike with select bnAbs bound are shown. Burton2012 (review)
VRC01: This review summarizes challenges to the development of an HIV-1 vaccine, lessons learned from scientific investigation and completed vaccine trials, and promising developments in HIV-1 vaccine design. VRC01 identification and characterization is discussed in detail. Kwong2012a (review)
VRC01: This review discusses how analysis of infection and vaccine candidate-induced antibodies and their genes may guide vaccine design. This MAb is listed as CD4 binding site bnAb, isolated after 2009 by fluorescence-activated cell sorting (FACS) using a resurfaced core gp120 molecule (RSC3). Bonsignori2012b (vaccine antigen design, vaccine-induced immune responses, review)
VRC01: Different adjuvants, including Freund's adjuvant (FCA/FIA), MF59, Carbopol-971P and 974P were compared on their ability to elicit antibody responses in rabbits. Combination of Carbopol-971P and MF59 induced potent adjuvant activity with significantly higher titer nAbs than FCA/FIA. There was no difference in binding of this MAb to gp140 SF162 with FIA, MF59, C974 and C974+MF59 adjuvants, but there was 3-fold decrease of antigenicity with C971 and C971+MF59 as compared to the unadjuvanted sample. Lai2012 (adjuvant comparison)
VRC01: Somatic hypermutations are preferably found in CDR loops, which alter the Ab combining sites, but not the overall structure of the variable domain. FWR of CDR are usually resistant to and less tolerant of mutations. This study reports that most bnAbs require somatic mutations in the FWRs which provide flexibility, increasing Ab breadth and potency. To determine the consequence of FWR mutations the framework residues were reverted to the Ab's germline counterpart (FWR-GL) and binding and neutralizing properties were then evaluated. VRC01, a CD4Bs Ab, was among the 17 bnAbs which were used in studying the mutations in FWR. Fig S4C described the comparison of Ab framework amino acid replacement vs. interactive surface area on VRC01. Klein2013 (neutralization, structure, antibody lineage)
VRC01: This study shows that Env immunogens fail to engage the germline-reverted forms of known bnAbs that target CD4BS. However, the elimination of a conserved NLGS at Asn276 in Loop D and the NLGS at positions 460 and 463, located in variable region 5 of Env increased the binding and activation of VRC01 and NIH45-46. This study showed that elimination of NLGS from these regions from Clade C Env 426c increases VRC01 binding. McGuire2013 (neutralization, antibody lineage)
VRC01: Antigenic properties of 2 biochemically stable and homogeneous gp140 trimers (A clade 92UG037 and C clade CZA97012) were compared with the corresponding gp120 monomers derived from the same percursor sequences. The trimers had nearly all the antigenic properties expected for native viral spikes and were markedly different from monomeric gp120. All gp120 and gp140 trimers bound tightly to VRC01 Fab, with the higher affinity for VRC01-gp140 interactions. the trimers also resisted conformational changes induced by VRC01, as demonstrated by 17b binding. Kovacs2012 (antibody binding site, neutralization, binding affinity)
VRC01: Glycan shield of HIV Env protein helps to escape the Ab recognition. Several of the PGT BnAbs interact directly with the HIV glycan coat. Crystal structures of Fabs PGT127 and PGT128 showed that the high neutralizing potency was mediated by cross-linking Env trimers on the viral surface. PGT128 was compared and referred as an order of magnitude more potent than VRC01. Pejchal2011 (glycosylation, structure, broad neutralizer)
VRC01: Intrinsic reactivity of HIV-1, a new property regulating the level of both entry and sensitivity to Abs has been reported. This activity dictates the level of responsiveness of Env protein to co-receptor, CD4 engagement and Abs. VRC01 has been used as a control CD4BS binding Ab in immuno-precipitation assay. Haim2011 (antibody interactions)
VRC01: Computational and crystallographic analysis and in vitro screening were employed to design a gp120 outer domain immunogen (eOD-GT6) that could bind to VRC01-class bNAbs and to their germline precursors. When multimerized on nanoparticles, eOD-GT6 activated germline and mature VRC01-class B cells and thus can be a promising vaccine prime. eOD-GT6 had 10 mutations relative to HXB2. Removal of glycans at positions 276 and 463 was necessary for GL affinity and removal of glycans at positions 386 and 403 also improved affinity. T278R, I371F, N460V are involved in the binding interface. L260F, K357R, G471S stabilize loops involved in the interface. eOD-GT6 bound both VRC01 mature and germline antibodies. Jardine2013 (glycosylation, vaccine antigen design, structure, antibody lineage)
VRC01: The study used the swarm of quasispecies representing Env protein variants to identify mutants conferring sensitivity and resistance to BnAbs. Libraries of Env proteins were cloned and in vitro mutagenesis was used to identify the specific AA responsible for altered neutralization/resistance, which appeared to be associated with conformational changes and exposed epitopes in different regions of gp160. The result showed that sequences in gp41, the CD4bs, and V2 domain act as global regulator of neutralization sensitivity. VRC01 was used as BnAb to screen Env clones and no significant change was observed with VRC01 neutralization. ORourke2012 (neutralization)
VRC01: Concomitant virus evolution and antibody maturation, leading to induction of a lineage of broadly neutralizing antibodies CH103-CH106, were followed in an African patient CH505 for 34 months from the time of infection. Compared to 30-36% VRC01, CH31 and NIH45-46 mutation frequencies of the published CD4 binding sites, CH103-CH106 exhibited 13-17% mutations. Liao2013 (broad neutralizer)
VRC01: This study reports the isolation of a panel of Env vaccine elicited CD4bs-directed macaque mAbs and genetic and functional features that distinguish these Abs from CD4bs MAbs produced during chronic HIV-1 infection. VRC01 was used as a control bNAb. Sundling2012 (vaccine-induced immune responses)
VRC01: Existing structural and sequence data was analyzed. A set of signature features for potent VRC01-like (PVL) and almost PVL abs was proposed and verified by mutagenesis. Sequences of VRC01, NIH45-46 and VRC-PG04 revealed a striking correlation for the length of CDRL3 (5 residues). West2012a (antibody lineage)
VRC01: Synthesis of an engineered soluble heterotrimeric gp140 is described. These gp140 protomers were designed against clade A and clade B viruses. The heterotrimer gp140s exhibited broader anti-tier1 isolate neutralizing antibody responses than homotrimer gp140. VRC01 was used to determine and compare the immunogenicity of homo and heterotrimers gp140s. Sellhorn2012 (vaccine antigen design)
VRC01: The use of computationally derived B cell clonal lineages as templates for HIV-1 immunogen design is discussed. VRC01 has been discussed in terms of immunogenic and functional characteristics of representative HIV-1 BnAbs and their reactions to antigens. Haynes2012 (antibody interactions, memory cells, vaccine antigen design, review, antibody polyreactivity, broad neutralizer)
VRC01: Crystal structures of unliganded core gp120 from HIV-1 clade B, C, and E were determined to understand the mechanism of CD4 binding capacity of unliganded HIV-1. The results suggest that the CD4 bound conformation represents "a ground state" for the gp120 core with variable loop. VRC01 was used as a control to prove whether the purified and crystallized gp120 is in the CD4 bound conformational state or not. Kwon2012 (structure)
VRC01: Polyclonal B cell responses to conserved neutralization epitopes are reported. Cross-reactive plasma samples were identified and evaluated from 308 subjects tested. VRC01 was used as a control mAb in the comprehensive set of assays performed. Tomaras2011 (neutralization, polyclonal antibodies)
VRC01: Several antibodies including 10-1074 were isolated from B-cell clone encoding PGT121, from a clade A-infected African donor using YU-2 gp140 trimers as bait. These antibodies were segregated into PGT121-like (PGT121-123 and 9 members) and 10-1074-like (20 members) groups distinguished by sequence, binding affinity, carbohydrate recognition, neutralizing activity, the V3 loop binding and the role of glycans in epitope formation. VRC01 was used as a control in virus neutralization assay. Detail information on the binding and neutralization assays are described in the figures S2-S11. Mouquet2012a (glycosylation, neutralization, binding affinity)
VRC01: YU2 gp140 bait was used to characterize 189 new MAbs representing 51 independent IgG memory B cell clones from 3 clade A or B HIV infected patients exhibiting broad neutralizing activity. The neutralizing potency of the antibodies was compared and none of these antibodies were as broad as VRC01. It has also been referred in discussing the efficiency of YU-2 gp140 trimer as a bait for Ab capture. Mouquet2011 (neutralization)
VRC01: The rational design of vaccines to elicit broadly neutralizing antibodies to HIV-1 is discussed in relation to understanding of vaccine recognition sites, the structural basis of interaction with HIV-1 env and vaccine developmental pathways. Role of VRC01 has been described regarding the sites of HIV-1 vulnerability to neutralizing antibodies and relating to humoral immune response during infection. VRC01 appears to target the site very effectively resulting in neutralization of ˜90% of circulating isolates. Kwong2011 (antibody binding site, neutralization, vaccine antigen design, review)
VRC01: A panel of glycan deletion mutants was created by point mutation into HIV gp160, showing that glycans are important targets on HIV-1 glycoproteins for broad neutralizing responses in vivo. Enrichment of high mannose N-linked glycan(HM-glycan) of HIV-1 glycoprotein enhanced neutralizing activity of sera from 8/9 patients. VRC01 was used as a control to compare the neutralizing activity of patients' sera. Lavine2012 (neutralization)
VRC01: Ab-driven escape and Ab role in infection control and prevention are reviewed. Main focus is on NAbs, but Ab acting through effector mechanisms are also discussed. Highly potent VRC01 (anti-CD4b) is discussed in the context of developing broadly cross-neutralizing antibodies. Overbaugh2012 (escape, review)
VRC01: Neutralization activity was compared against MAb 10E8 and other broad and potent neutralizers in a 181-isolate Env-pseudovirus panel. 2F5 neutralized 89% of viruses at IC50<50 μg/ml and 75% of viruses at IC50<1 μg/ml, compared with 98% and 72% of MAb 10E8, respectively. Huang2012a (neutralization)
VRC01: Antigenic properties of undigested VLPs and endo H-digested WT trimer VLPs were compared. Binding to E168K+ N189A WT VLPs was stronger than binding to the parent WT VLPs, uncleaved VLPs. There was no significant correlation between E168K+N189A WT VLP binding and VRC01 neutralization, while trimer VLP ELISA binding and neutralization exhibited a significant correlation. BN-PAGE shifts using digested E168K + N189A WT trimer VLPs exhibited prominence compared to WT VLPs. Tong2012 (neutralization, binding affinity)
VRC01: The role of V1V2 in the resistance of HIV-1 to neutralizing Abs was studied using a panel of neutralization-sensitive and -resistant HIV-1 variants and through exchanging regions of Env between neutralization-sensitive and -resistant viruses. An increase in the length of the V1V2 loop and/or the number of potential N-linked glycosylation sites (PNGS) in that same region of Env was directly involved in the neutralization resistance. The introduction of a longer V1V2 loop with more PNGS of HIV-1 from contemporary seroconverters into the background of Env of HIV-1 from historical seroconverters resulted in a 2-fold increase in neutralization resistance to MAb VRC01 for 10/18 viruses. vanGils2011 (glycosylation, neutralization, escape)
VRC01: To improve the immunogenicity of HIV-1 Env vaccines, a chimeric gp140 trimer in which V1V2 region was replaced by the GM-CSF cytokine was constructed. We selected GM-CSF was selected because of its defined adjuvant activity. Chimeric EnvGM-CSF protein enhanced Env-specific Ab and T cell responses in mice compared with wild-type Env. Probing with neutralizing antibodies showed that both the Env and GM-CSF components of the chimeric protein were folded correctly. 3 proteins were studied: Env-wild-type, Env-ΔV1V2, Env-hGM-CSF. MAb VRC01 against discontinuou