Direct and indirect mechanisms mediating apoptosis during HIV infection: contribution to in vivo CD4 T cell depletion.

The gradual depletion of CD4+ T lymphocytes during the development of AIDS may be due, at least in part, to a process referred to as apoptosis. This process involves a Ca2+ dependent nuclear endonuclease that cleaves the chromatin at internucleosomal junctions. In addition, we have recently provided evidence that apoptosis may be responsible not only for the progressive loss of CD4+ T lymphocytes but may be operative in CD8+ T lymphocytes as well. Here, we describe mechanisms which by direct and indirect pathways may induce apoptosis during HIV infection and thus leading to elimination of T cells.