We examined the gene expression profiles in ex vivo human CD4+ and CD8+ T cells from untreated HIV-infected individuals at different clinical stages and rates of disease progression. Profiles of pure CD4+ and CD8+ T cells subsets from HIV-infected nonprogressors who controlled viremia were indistinguishable from HIV-uninfected individuals. Similarly, no gene clusters could distinguish T cells from individuals with early from chronic progressive HIV infection, whereas differences were observed between uninfected or nonprogressors versus early or chronic progressors. In early/chronic HIV infection, three characteristic gene expression signatures were observed: (1) CD4+ and CD8+ T cells showed increased expression of interferon stimulated genes (ISGs). However, some ISGs including CXCL9, CXCL10, and CXCL11, and the IL15R? in both CD4+ and CD8+ T cells and the anti-HIV ISG APOBEC3G in CD4+ T cells, were not upregulated. (2) CD4+ and CD8+ T cells showed a cluster similar to that observed in thymocytes, and (3) more genes were differentially regulated in CD8+ T cells than in CD4+ T cells, including a cluster of genes downregulated exclusively in CD8+ T cells. In conclusion, HIV infection induces a persistent T cell transcriptional profile, early in infection, characterized by a dramatic but potentially aberrant interferon response, and a profile suggesting an active thymic output.

We studied a cohort of HIV infected individuals with various clinical stages of HIV infection and healthy uninfected volunteers as a control group (Table 1). We included 5 individuals with early HIV infection (A), five with chronic progressive HIV infection (C), five individuals with non-progressive HIV infection with low or undetectable viral loads (L) and five HIV uninfected individuals (N). The HIV infected individuals were never on therapy prior to entering the study. Samples were taken once from each donor.