This article is part of the supplement: AIDS Vaccine 2009
Oral presentation
S01-04 OA. Phenotypic analyses of CD8+ T cells that mediate virus inhibition from HIV-1 vaccinees and HIV-1+ virus controllers
1 DHVI and Surgery, Duke University Medical School, Durham, USA
2 ImmunoTechnology Section, Vaccine Research Center, NIAID, NIH, Bethesda, MD, USA
3 Immunology Core Section, Vaccine Research Center, NIAID, NIH, Bethesda, MD, USA
4 Duke University Medical Center; DHVI and Surgery, Durham, NC, USA
5 University of Alabama, Department of Medicine, Birmingham, AL, USA
6 Duke University Medical Center, Department of Pediatrics, Durham, NC, USA
7 Duke University Medical Center; DHVI and Medicine, Durham, NC, USA
8 Duke University Medical Center; DHVI, Immunology and Surgery, Durham, NC, USA
9 Duke University Medical Center; Department of Surgery, Durham, NC, USA
10 Viral Pathogenesis Laboratory; Vaccine Research Center, NIAID, NIH, Bethesda, MD, USA
11 Duke University Medical Center; DHVI, Immunology, and Medicine, Durham, NC, USA
12 Duke University Medical Center, DHVI, Surgery and Immunology, Durham, NC, USA
Retrovirology 2009, 6(Suppl 3):O1 doi:10.1186/1742-4690-6-S3-O1
The electronic version of this article is the complete one and can be found online at: http://www.retrovirology.com/content/6/S3/O1
| Published: | 22 October 2009 |
© 2009 Freel et al; licensee BioMed Central Ltd.
Background
CD8-mediated virus inhibition can be detected in HIV-1+ subjects controlling virus replication in the absence of ART. Characterizing the CD8+ T cells that mediate virus inhibition is important for determining the nature of CD8+ T cells that need to be elicited by an HIV-1 vaccine.
Methods
We used a 3-day CD8+ T cell mediated virus inhibition assay (CD8 VIA) to assess CD8+ function. Primary CD4+ enriched lymphocytes were infected with reporter viruses expressing transmitted/founder envelopes in the presence of serial dilutions of autologous CD8+ T cells. We examined activated CD8+ T cells from 22 HIV-1+ subjects (of which 15 were virus controllers (VC)), 37 HIV-1 vaccinees (DNA prime, rAd5 boost encoding HIV-1 Env and Gag-Pol) and 6 seronegative donors. Phenotypic analysis of HIV-1 specific CD8+ cells was determined by 13 color flow cytometry. Phenotypically-defined CD8+ T cell subsets from selected donors were sorted by flow cytometry and tested for virus suppression.
Results
VCs had robust antiviral activity against both transmitted/founder and NL4-3 enveloped viruses (1.43 +/- 0.67 log reduction). Among vaccinees, CD8 VIA correlated with HIV-1 specific CD107a expression; and weakly with IFN-gamma expression. No correlations were observed with CD8+ cell expression of IL-2, TNF-alpha, or MIP-1 beta. Virus inhibition by sorted cells was absent from naive CD8+ T cells; the predominant activity was from central and early effector memory populations.
Conclusion
CD8-mediated virus inhibition, as measured in a 3-day assay with early transmitted reporter viruses, was present in HIV-1+ subjects and vaccinees. Among HIV-1+ subjects, the activity was most robust in virus controllers. Virus suppression correlates most strongly with CD107a, and may come primarily from central memory populations. These data provide insight into the mechanisms of viral inhibition, and suggest that functional analyses of CD8+ T cell mediated virus inhibition could identify benchmarks for successful T-cell directed vaccine strategies.