Both CD31+ and CD31- Naive CD4+ T Cells Are Persistent HIV Type 1-Infected Reservoirs in Individuals Receiving Antiretroviral Therapy

Background. Naive T cell recovery is critical for successful immune reconstitution after antiretroviral therapy (ART), but the relative contribution of CD31+ and CD31- naive T cells to immune reconstitution and viral persistence is unknown. Methods. In a cross-sectional (n = 94) and longitudinal (n = 10) study of human immunodeficiency virus (HIV)-infected patients before and after ART, we examined the ratio of CD31+ to CD31- naive CD4+ T cells. In the longitudinal cohort we then quantified the concentration of HIV-1 DNA in each cell subset and performed single-genome amplification of virus from memory and naive T cells. Results. Patients receiving ART had a higher proportion of CD31+ CD4+ T cells than HIV-1-infected individuals naive to ART and uninfected control subjects (P < .001 and .007, respectively). After 24 months of ART, the proportion of CD31+ naive CD4+ T cells did not change, the concentration of HIV-1 DNA in memory CD4+ T cells significantly decreased over time (P < .001), and there was no change in the concentration of HIV-1 DNA in CD31+ or CD31- naive CD4+ T cells (P = .751 and .251, respectively). Single-genome amplification showed no evidence of virus compartmentalization in memory and naive T cell subsets before or after ART. Conclusions. After ART, both CD31+ and CD31- naive CD4+ T cells expand, and both subsets represent a stable, persistent reservoir of HIV-1.