Function of ex vivo stimulated Natural killer T cells from patients with chronic HIV-1 infection

Natural killer T (NKT) cells are innate immune cells that are responsible for the first line of antiviral defense, through crosstalk with downstream antigen-presenting cells, natural killer cells, and adaptive immune cells. Previous studies have indicated that NKT cell function is severely impaired in patients with chronic HIV-1 infection. It was reported that alpha-galactosylceramide, a potent agonist antigen for NKT cells, failed to trigger the expansion of NKT cells, or the production of anti-viral cytokines by NKT cells from HIV-1 infected patients in an in vitro assay, in which peripheral blood mononuclear cells (PBMCs) were cultured in the presence of alpha-galactosylceramide. In this study, we stimulated banked peripheral blood mononuclear cells from HIV-1-infected patients with dendritic cells (DC) generated ex vivo and loaded with alpha-galactosylceramide. The results showed that NKT cells were expanded in HIV infected subjects except in patients with advanced AIDS. Expanded NKT cells were capable of producing antiviral cytokines. Our results indicate that NKT cells in HIV infected individuals are potential targets for therapeutic intervention.