Inhibitory potential of subpopulations of CD8+ T cells in HIV-1-infected elite suppressors.
Elite controllers or suppressors (ES) are HIV-1-infected individuals who suppress viral replication to clinically undetectable levels without antiretroviral therapy. Understanding the mechanisms by which ES control viral replication may prove informative for the design of a therapeutic vaccine. Qualitative differences in the CD8(+) T cell response have been implicated in control. Therefore, we isolated CD8(+) T cells from ES and characterized the ability of sorted memory and activation subpopulations to control viral replication at various effector-to-target cell ratios using a novel modification of a CD8(+) T cell suppression assay. The effector memory and terminal effector subpopulations of memory CD8(+) T cells had the highest inhibitory potential over the course of a 3-day in vitro infection. Interestingly, after 5 days of infection, central memory CD8(+) T cells were also very effective at suppressing viral replication. No significant correlation between the suppression of viral replication and the number of HIV-1-specific CD8(+) T cells was observed. HLA-DR(-) CD38(+) CD8(+) T cells possessed the lowest inhibitory potential of the activation subpopulations. Taken together, our data suggest that there are key differences in the magnitude and kinetics of the suppression of HIV-1 replication by different CD8(+) T cell subsets. These data should guide the development of an effective, cellular therapeutic vaccine that has the potential to elicit similar CD8(+) T cell responses.
Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Robert W
RW
Buckheit
Maria
M
Salgado
Robert F
RF
Silciano
Joel N
JN
Blankson
D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D005434:Flow Cytometry; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1; D006801:Humans