| Title: | Immunodominant HIV-1 Cd4+ T Cell Epitopes in Chronic Untreated Clade C HIV-1 Infection |
| Author: |
Ramduth, Danni; Day, Cheryl L.; Thobakgale, Christina F.; Mkhwanazi, Nompumelelo P.; de Pierres, Chantal; Reddy, Sharon; van der Stok, Mary; Mncube, Zenele; Nair, Kriebashne; Moodley, Eshia S.; Coovadia, Hoosen M.; Kiepiela, Photini; Kaufmann, Daniel; Streeck, Hendrik; Goulder, Philip J.; Walker, Bruce David
Note: Order does not necessarily reflect citation order of authors. |
| Citation: | Ramduth, Danni, Cheryl L. Day, Christina F. Thobakgale, Nompumelelo P. Mkhwanazi, Chantal de Pierres, Sharon Reddy, Mary van der Stok, et al. 2009. Immunodominant HIV-1 Cd4+ T Cell Epitopes in Chronic Untreated Clade C HIV-1 Infection. PLoS ONE 4(4): e5013. |
| Full Text & Related Files: |
2661367.pdf (701.0Kb; PDF)
|
| Abstract: | Background: A dominance of Gag-specific CD8+ T cell responses is significantly associated with a lower viral load in individuals with chronic, untreated clade C human immunodeficiency virus type 1 (HIV-1) infection. This association has not been investigated in terms of Gag-specific CD4+ T cell responses, nor have clade C HIV-1–specific CD4+ T cell epitopes, likely a vital component of an effective global HIV-1 vaccine, been identified. Methodology/Principal Findings: Intracellular cytokine staining was conducted on 373 subjects with chronic, untreated clade C infection to assess interferon-gamma (IFN-γ) responses by CD4+ T cells to pooled Gag peptides and to determine their association with viral load and CD4 count. Gag-specific IFN-γ–producing CD4+ T cell responses were detected in 261/373 (70%) subjects, with the Gag responders having a significantly lower viral load and higher CD4 count than those with no detectable Gag response (p<0.0001 for both parameters). To identify individual peptides targeted by HIV-1–specific CD4+ T cells, separate ELISPOT screening was conducted on CD8-depleted PBMCs from 32 chronically infected untreated subjects, using pools of overlapping peptides that spanned the entire HIV-1 clade C consensus sequence, and reconfirmed by flow cytometry to be CD4+ mediated. The ELISPOT screening identified 33 CD4+ peptides targeted by 18/32 patients (56%), with 27 of the 33 peptides located in the Gag region. Although the breadth of the CD4+ responses correlated inversely with viral load (p = 0.015), the magnitude of the response was not significantly associated with viral load. Conclusions/Significance: These data indicate that in chronic untreated clade C HIV-1 infection, IFN-γ–secreting Gag-specific CD4+ T cell responses are immunodominant, directed at multiple distinct epitopes, and associated with viral control. |
| Published Version: | doi:10.1371/journal.pone.0005013 |
| Other Sources: | http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2661367/pdf/ |
| Terms of Use: | This article is made available under the terms and conditions applicable to Other Posted Material, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#LAA |
| Citable link to this page: | http://nrs.harvard.edu/urn-3:HUL.InstRepos:4889439 |
Contact administrator regarding this item (to report mistakes or request changes)