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Activated CD8+ T cells from HIV-infected people are anergic and apoptotic.
Lewis DE; Tang DN; Rodgers JR; Dept. of Microbiology and Immunology,
November 30, 1993
Int Conf AIDS. 1993 Jun 6-11;9(1):32 (abstract no. WS-A16-2). Unique

CD8+ T cells are functionally defective early in HIV infection and HIV-specific cytotoxic activity is lost late in the disease. The mechanisms for these defects remain unclear. Separated CD8+ T cells from 11 patients with asymptomatic HIV infection (CD4 percentage 22 +/- 7) exhibited increased apoptosis when incubated in medium overnight, whereas, cells from only 1 of 5 uninfected people studied showed a similar phenomenon. Examination of the CD8- population in the same patients showed increased apoptosis in 5 of 11 tested. From 10-50% of the DNA from the CD8+ cells exhibited apoptosis as measured by quantitative DNA fragmentation. Apoptosis was reduced by using aurintricarboxylic acid (AT), an endonuclease inhibitor. Flow sorting of CD8+ subpopulations from 7 patients showed that both CD8+ DR+ CD57+ and CD57- cells were apoptotic. IL-2 reduced apoptosis in CD57- but not in CD57+ cells. CD8+ CD57+ cells from both normals (5) and infected (2) people were unable to respond to T cell receptor signals by proliferation. Overall, these results suggest that some cells from subpopulations of activated CD8+ T cells in HIV-infected people are functionally anergic and apoptotic. These observations could be related to the loss of antigen specific T cell cytotoxic activity late in infection.

*Acquired Immunodeficiency Syndrome/IMMUNOLOGY *Antigens, CD/IMMUNOLOGY *Antigens, CD8/IMMUNOLOGY *HIV *HIV Infections/IMMUNOLOGY *Lymphocyte Transformation *T-Lymphocyte Subsets/IMMUNOLOGY