Impairment of CD1d-restricted Natural Killer T cells in chronic HIV-1 clade C infection

Abstract

Recent studies suggest that Natural Killer T (NKT) cells play a role in early antiviral pathogenesis and have been shown to play a critical role in protective immunity to many infections observed in immunocompromised individuals, including mycobacterium tuberculosis. NKT cells are rapidly depleted in chronic human immunodeficiency virus type 1 (HIV-1) clade B infection and no known studies to date have yet assessed the impact of HIV-1 infection on NKT cell number and function in sub-Saharan Africa where HIV- 1 clade C is the predominant subtype. We aimed to characterize the phenotypic and functional characteristics of NKT cells in HIV-1 clade C-infected Africans at different stages of HIV-1 disease. We observed a significant decline of NKT cell numbers in advanced HIV-1 disease as well as activation and functional impairment of NKT cells in individuals with low CD4 T cell counts. The loss of NKT cells was largely driven by a reduction in the CD4+ and CD4negCD8neg NKT cell subsets in advanced disease. Overall, we demonstrated significant impairment of the NKT cell compartment in progressive HIV-1 clade C disease that might play an important role in the modulation of immune function in HIV-1 infection