Phenotypic Characteristics and Function of NK Cell Subsets in cART-Treated HIV-1-Infected Individuals

Natural killer (NK) cell plays an important role in an innate immune response against viral infection. The kinetics regulation and functional consequences of NK cells in the pathogeneses of diseases are uncertain. We analyzed NK cell distribution and function of successfully combination antiretroviral therapy (cART)-treated HIV-1 infected individuals in Khon Kaen Regional Hospital, Thailand. The results demonstrated that increased percentage and the total number of NK cell in cART-treated HIV-1 infected patients with preferential high levels of CD56dimCD16+ and CD56-CD16+ subsets when compared with a control group even in undetectable viral load (<40 copies per milliliter). Concomitantly, decreased cytotoxic activity measured by CD107asurface expression with maintained IFN-γ production implied the impairment of cytolytic activity was not recovered after cART treatment. Thus, altered NK cell frequency and function by HIV-1 infection are not completely recovered with cART, which may contribute to impaired cellular immune response and persistence of HIV-1.