CD4(+) and CD8(+) T cell death during human immunodeficiency virus infection in vitro

We have evaluated the death of CD4(+) and CD8(+) T cells during in vitro hu man immunodeficiency virus (HIV) infection of peripheral blood mononuclear cells (PBMC) and tonsilar tissue. Acute infections with several X4 and R5 H IV isolates induced a decrease in cell viability that was higher in infecti ons with X4 viruses and correlated with an increased rate of CD4 ' T-cell d eath. In CD4(+) T cells, the primary X4 isolate AOM induced higher levels o f death than the laboratory X4 isolates IIIB and NL4-3 or the R5 isolates B at and MDM. An effect on CD8(+) T-cell viability was exclusively observed i n infections by X4 viruses, including the NL4-3 strain, in both PBMC and to nsilar tissue. This effect was dependent on the env gene of the infecting i solate and required productive HIV replication in CD4(+) but not in CD8(+) T cells. Our results suggest that X4 and R5 HIV isolates depleted CD4(+) T cells to a different extent and that CD8(+) T-cell viability may also be af fected by mechanisms other than those acting in CD4(+) T cells. (C) 2001 Ac ademic Press.