Search T Helper/CD4+ T-Cell Epitope Database

Found 3 matching records:

Displaying record number 200897

Download this epitope record as JSON.

HXB2 Location	Gag(166-181) p24(34-49) DNA(1285..1332)	Gag Epitope Map
Author Location	p24( HXB2)
Epitope	PEVIPMFSALSEGATP	Epitope Alignment
Subtype	B
Species (MHC/HLA)	human(DR1)
Immunogen	in vitro stimulation or selection
Experimental methods	CD4 T-cell Elispot - IFNγ
Keywords	epitope processing, vaccine antigen design, characterizing CD8+ T cells

Notes

• Multiple HLA class I-restricted and class II-restricted T-cell epitopes were shown to be processed and presented from an exogenously added HIV-1 gag-p24 peptide complexed to a heat shock protein. T-cell recognition of the complex was shown to be inhibited by brefeldin A indicating an endoplasmic reticulum-dependent pathway.

References

SenGupta2004 Devi SenGupta, Philip J. Norris, Todd J. Suscovich, Mina Hassan-Zahraee, Howell F. Moffett, Alicja Trocha, Rika Draenert, Philip J. R. Goulder, Robert J. Binder, Daniel L. Levey, Bruce D. Walker, Pramod K. Srivastava, and Christian Brander. Heat Shock Protein-Mediated Cross-Presentation of Exogenous HIV Antigen on HLA Class I and Class II. J. Immunol., 173(3):1987-1993, 1 Aug 2004. PubMed ID: 15265933. Show all entries for this paper.

Displaying record number 200976

Download this epitope record as JSON.

HXB2 Location	Gag(166-181) p24(34-49) DNA(1285..1332)	Gag Epitope Map
Author Location	p24(168-177 NY-5)
Epitope	PEVIPMFSALSEGATP	Epitope Alignment
Epitope Name	PP16
Subtype	B
Species (MHC/HLA)	human(DR1)
Immunogen	HIV-1 infection
Patient MHC/HLA	DQ5, DQ7, DR1, DR11, DRw52
Country	United States
Experimental methods	CD4 T-cell Elispot - IFNγ, Chromium-release assay, Proliferation
Keywords	rate of progression, acute/early infection, early treatment, variant cross-reactivity

Notes

• 5 CD4-T cell epitopes in Gag-p24 were studied, and a minimum epitope length of 6-16 amino acids was found to be required for CD4+ T-cell proliferation. Cross-clade recognition was studied and found to be impaired in 17/32 variants tested.
• Patient AC-25 was an acute seroconvertor at the time of sampling, infected with HIV-1 in 1998, and given ARVs during primary infection. The study subject was resampled 18 months after initiation of therapy.
• Natural variants of the epitope PEVIPMFSALSEGATP diminished the level of the response, including pevipmfPalsegStp and pevipmfsalsegStp, found in CRF01_AE; peIipmfTalsegatp, clade C; pevipmfsalSegatp, clade B; pevipmfTalsegatp, clades A, B and C; and pevipVfsalsegatp, clade A.
• Minimum length peptides for the epitopes studies were not particularly optimal, and peptides longer than the minimum, up to 22 amino acids, were often as potent, in marked contrast to CD8+ T-cell responses.

References

Norris2004 Philip J. Norris, Howell F. Moffett, Christian Brander, Todd M. Allen, Kristin M. O'Sullivan, Lisa A. Cosimi, Daniel E Kaufmann, Bruce D. Walker, and Eric S. Rosenberg. Fine Specificity and Cross-Clade Reactivity of HIV Type 1 Gag-Specific CD4+ T Cells. AIDS Res. Hum. Retroviruses, 20(3):315-325, Mar 2004. PubMed ID: 15117455. Show all entries for this paper.

Displaying record number 201090

Download this epitope record as JSON.

HXB2 Location	Gag(166-181) p24(34-49) DNA(1285..1332)	Gag Epitope Map
Author Location	p24
Epitope	PEVIPMFSALSEGATP	Epitope Alignment
Epitope Name	PP16
Species (MHC/HLA)	human(DR1)
Immunogen	HIV-1 infection
Experimental methods	CD4 T-cell Elispot - IFNγ, Flow cytometric T-cell cytokine assay, Proliferation, Tetramer binding
Keywords	binding affinity, escape, optimal epitope, antagonism

Notes

• This study demonstrates a mechanism of antagonism by a peptide shorter than the minimum length epitope for an HIV p24-specific CD4+ T-cell clone.
• Truncation of the peptide from PEVIPMFSALSEGATP (PP16) to PEVIPMFSALSEG (PG13) rendered the peptide unable to elicit proliferation, IFN-γ release, or serine esterase release, even though it retained strong binding to MHC.
• Although both the original and truncated peptide-MHC complexes bound TCR clone, PEVIPMFSALSEGATP-DR1 tetramer bound with higher avidity than PEVIPMFSALSEG-DR1 tetramer, suggesting that tighter association of the peptide-MHC complex with the TCR is associated with the extent of T-cell activation.
• G/P substitution in the original full-length peptide (PEVIPMFSALSE[g/p]ATP) led to complete loss of agonist activity, and PEVIPMFSALSEpATP became antagonistic.

References

Norris2006 Philip J. Norris, Jennifer D. Stone, Nadezhda Anikeeva, John W. Heitman, Ingrid C. Wilson, Dale F. Hirschkorn, Margaret J. Clark, Howell F. Moffett, Thomas O. Cameron, Yuri Sykulev, Lawrence J . Stern, and Bruce D. Walker. Antagonism of HIV-Specific CD4+ T Cells by C-Terminal Truncation of a Minimum Epitope. Mol. Immunol., 43(9):1349-1357, Mar 2006. PubMed ID: 16216327. Show all entries for this paper.