Search T Helper/CD4+ T-Cell Epitope Database

Found 3 matching records:

Displaying record number 201716

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HXB2 Location	Gag(25-41) p17(25-41) DNA(862..912)	Gag Epitope Map
Author Location	Gag
Epitope	GKKKYKLKHIVWASREL	Epitope Alignment
Epitope Name	OLP-4
Species (MHC/HLA)	human(DRB1*01:01, DRB1*07:01, DRB1*08:01, DRB1*11:01, DRB1*13:02, DRB1*13:03, DRB3*01:01, DRB3*03:01, DRB4*01:01, DRB5*01:01)
Immunogen	HIV-1 infection
Country	United States
Experimental methods	CD4 T-cell Elispot - IFNγ, HLA binding
Keywords	binding affinity, immunodominance, HLA cross-presentation

Notes

• 67 Gag and Nef peptides restricted by HLA-DRB1 were characterized immunologically in 17 controllers and 9 progressors. HLA allele DRB1*15:02 was associated with low HIV-1 viremia and could promiscuously present peptides with lower avidity. HLA DRB1*03:01, however, was associated with high viremia and specific presentation of peptides. Moreover, Nef peptides were exclusively restricted by HLA-DRB1 variants linked with low viremia. Individuals with low viremia-linked HLA-DRB1 alleles also had greater breadth of HIV-specific CD4+ T cell responses. DRB1 allelic expression can impact HIV replication.
• Immunodominant overlapping peptide-4 (OLP-4), GKKKYKLKHIVWASREL, was promiscuous as it was restricted by 10 different HLA-DR across the HIV proteome as determined by IFN-γ EliSpot.
• OLP-4 promiscuity was evident in that it could bind 13 different HLA-DRB1 in HLA-binding competition assays. IC₅₀ values for each peptide-DBR1 interaction were *0101 (33 nM), *0301 (915 nM), *0401 (82 nM), *0405 (119 nM), *0701 (42 nM), *0802 (14 nM), *0901 (105 nM), *1001 (28 nM), *1101 (52 nM), *1201 (450 nM), *1302 (739 nM), *1501 (78 nM) and *1602 (84 nM).

References

Ranasinghe2013 Srinika Ranasinghe, Sam Cutler, Isaiah Davis, Richard Lu, Damien Z. Soghoian, Ying Qi, John Sidney, Gregory Kranias, Michael D. Flanders, Madelene Lindqvist, Bjorn Kuhl, Galit Alter, Steven G. Deeks, Bruce D. Walker, Xiaojiang Gao, Alessandro Sette, Mary Carrington, and Hendrik Streeck. Association of HLA-DRB1-Restricted CD4+ T Cell Responses with HIV Immune Control. Nat. Med., 19(7):930-933, Jul 2013. PubMed ID: 23793098. Show all entries for this paper.

Displaying record number 201478

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HXB2 Location	Gag(25-41) p17(25-41) DNA(862..912)	Gag Epitope Map
Author Location	Gag
Epitope	GKKKYKLKHIVWASREL	Epitope Alignment
Species (MHC/HLA)	human
Immunogen	HIV-1 infection
Country	Germany, United States
Experimental methods	Flow cytometric T-cell cytokine assay
Keywords	elite controllers

Notes

• The study demonstrated that HIV-1-specific IL-21 CD4+ T cell responses might contribute to the control of viral replication in humans. Specifically, triggering of IL-21 by CD4+ T cells was significantly enriched in HIV-1 controllers, while loss of IL-21-secreting CD4+ was characteristic for subjects with persistent viremia and progressive disease. Expansion of IL-21 CD4+ T cells in acute infection resulted in lower viral set points. IL-21 production by CD4+ T cells of HIV controllers enhanced perforin production by HIV-1-specific CD8+ T cells from chronic progressors even in late stages of disease, and effector CD8+ T cells were more efficient in inhibiting viral replication in vitro after IL-21 binding.
• This peptide belongs to a set of overlapping peptides spanning HIV Gag. It elicited IFN-γ secretion but not IL-21 secretion in one HIV controller.

References

Chevalier2011 Mathieu F. Chevalier, Boris Jülg, Augustine Pyo, Michael Flanders, Srinika Ranasinghe, Damien Z. Soghoian, Douglas S. Kwon, Jenna Rychert, Jeffrey Lian, Matthias I. Muller, Sam Cutler, Elizabeth McAndrew, Heiko Jessen, Florencia Pereyra, Eric S. Rosenberg, Marcus Altfeld, Bruce D. Walker, and Hendrik Streeck. HIV-1-Specific Interleukin-21+ CD4+ T Cell Responses Contribute to Durable Viral Control through the Modulation of HIV-Specific CD8+ T Cell Function. J. Virol., 85(2):733-741, Jan 2011. PubMed ID: 21047960. Show all entries for this paper.

Displaying record number 201646

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HXB2 Location	Gag(25-41) p17(25-41) DNA(862..912)	Gag Epitope Map
Author Location	p17(25-41)
Epitope	GKKKYKLKHIVWASREL	Epitope Alignment
Epitope Name	OLP 4
Subtype	B
Species (MHC/HLA)	human
Immunogen	HIV-1 infection
Country	United States
Experimental methods	CD4 T-cell Elispot - IFNγ
Keywords	immunodominance, novel epitope

Notes

• 93 treatment-naive subjects in various stages of HIV-1 infection were analyzed for CD4 T-cell responses to the HIV B clade proteome using 410 overlapping peptides (OLPs). HTL responses were detected in 92% patients and breadth of these Gag responses were inversely correlated to viral load (VL). Targeting of 3 immunodominant Gag peptides was found to be linked to control of HIV infection.
• Gag/Env mean response ratios were associated with effective immunity, and a robust marker of viral control, the lowest ratios being found in elite controllers and the highest in high-VL progressors.
• 11% of subjects responded to this immunodominant Gag-p17 peptide GKKKYKLKHIVWASREL.

References

Ranasinghe2012 Srinika Ranasinghe, Michael Flanders, Sam Cutler, Damien Z. Soghoian, Musie Ghebremichael, Isaiah Davis, Madelene Lindqvist, Florencia Pereyra, Bruce D. Walker, David Heckerman, and Hendrik Streeck. HIV-Specific CD4 T Cell Responses to Different Viral Proteins Have Discordant Associations with Viral Load and Clinical Outcome. J. Virol., 86(1):277-283, Jan 2012. PubMed ID: 22031937. Show all entries for this paper.