Rapid Degranulation of NK Cells following Activation by HIV-Specific Antibodies

Abstract

Ab-dependent cellular cytotoxicity (ADCC) Abs stimulate NK cell effector functions and play a role in protecting from and controlling viral infections. We characterized ADCC Abs in a cross-sectional cohort of 80 HIV-infected subjects not on antiretroviral therapy. We analyzed ADCC response by killing fluorescently labeled target cells, as well as expression of IFN-gamma and the degranulation marker CD107a from activated NK cells as measured by a novel intracellular cytokine assay. HIV-specific ADCC directed toward Envelope proteins were present in the majority of 80 untreated HIV-infected individuals measured by killing function. Similarly, most subjects had HIV-specific Abs that mediated de..