HIV GENE-EXPRESSION ENHANCES T-CELL SUSCEPTIBILITY TO HYDROGEN PEROXIDE-INDUCED APOPTOSIS

A human T cell lineage was used to determine the possible effects of HIV infection on T cell antioxidant status. On inoculation into serum-free culture, 8E5, a constitutive HIV-expressing T cell line, underwent apoptosis whereas cell death was not observed with the uninfected A3.01 or latently HIV-infected 8E5L T cell lines. 8E5 survival was markedly prolonged by supplementing the serum-free medium with either A3.01-conditioned medium, catalase, vitamin E, or 2-mercaptoethanol, but supplementation with ascorbic acid, glutathione, or N-acetylcysteine had no effect. Consistent with their being in a state of oxidative stress, 8E5 cells displayed reduced levels of catalase activity, and were more susceptible to killing by exogenous hydrogen peroxide (H2O2) than A3.01 and 8E5L cells. These results demonstrate an inverse correlation between HIV gene expression and antioxidant status in human T cells. Enhanced cytotoxicity of HIV-infected, antioxidant-deficient CD4 T cells following exposure to H2O2 in lymphoid tissues responding to opportunistic pathogens may contribute to the depletion of CD4 T cells in AIDS.