Th17 cells and HIV infection

Purpose of review This review summarizes the recent literature about the potential perturbation and role of Th17 cells in HIV pathogenesis. We discuss the recent findings on Th17 deficiency in HIV/simian immunodeficiency virus (SIV) infection and how this deficiency may impact the mucosal host defenses, potentially contributing to chronic immune activation. Recent findings Th17 cells have been implicated in host defense against a variety of pathogens and are involved in the pathogenesis of autoimmune diseases. Recently, Th17 cells were shown to be perturbed during HIV infection in humans and SIV infection in nonhuman primates. Th17 cells were found to be infected in vitro by HIV and SIV and are significantly depleted in the gastrointestinal tract of HIV-infected individuals. In monkeys, Th17 cells are only depleted in the pathogenic SIV infection of rhesus macaques, which correlates with the progression to AIDS in these primates, whereas they remain intact in the nonpathogenic SIV infection of African green monkeys or sooty mangabeys. Summary Th17 cells appear to be perturbed during HIV and SIV infection. This finding could have important implications in understanding the disruption of mucosal defenses in the gastrointestinal tract and potentially in predicting opportunistic infections during the course of HIV disease.