Residual T cell activation and skewed CD8+ T cell memory differentiation despite antiretroviral therapy-induced HIV suppression.

HIV infection results in excessive T cell activation and dysfunction which may persist even during effective antiretroviral therapy (ART). The dynamics of immune 'deactivation' and extent to which T cell memory subsets normalize after ART are unclear. We longitudinally assessed the influence of 1 year of ART on the phenotype of T cells in HIV-infected African women, relative to matched HIV-uninfected women, using activation (CD38, HLA-DR) and differentiation markers (CD27, CD45RO). ART induced a substantial reduction in T cell activation, but remained higher than HIV-uninfected controls. ART largely normalized the distribution of CD4+ T cell memory subsets, while the distribution of CD8+ T cell memory subsets remained significantly skewed compared to HIV-uninfected individuals. Thus, there was a considerable but only partial reversal of T cell defects upon ART. Understanding T cell impairment may provide important insights into mechanisms of HIV pathogenesis in the era of ART.