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 H IV infection on T cell antioxidant status. On inoculation into serum-f ree 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 marked ly prolonged by supplementing the serum-free medium with either A3.01- conditioned medium, catalase, vitamin E, or 2-mercaptoethanol, but sup plementation 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 mor e susceptible to killing by exogenous hydrogen peroxide (H2O2) than A3 .01 and 8E5L cells. These results demonstrate an inverse correlation b etween HIV gene expression and antioxidant status in human T cells. En hanced cytotoxicity of HIV-infected, antioxidant-deficient CD4 T cells following exposure to H2O2 in lymphoid tissues responding to opportun istic pathogens may contribute to the depletion of CD4 T cells in AIDS .