Significance of T cell apoptosis for macrophages in HIV infection

Apoptosis is a major form of cell death in HIV infection. This review presents current ideas on the role of apoptosis in the development of AIDS. HIV may cause apoptosis either directly in individual CD4+ T cells through cellular infection and through the release of gp120 envelope protein, or indirectly by initiating systemic disturbances in the immune system. Furthermore, although apoptosis is often assumed to be a biological dead end, linear, unintegrated retroviral DNA survives apoptosis in avian leukosis virus systems. Macrophages avidly phagocytose apoptosing cells, and the viral DNA in apoptotic debris might spontaneously transfect macrophages and lead to the production of new virions. Such a hypothetical accessory infection pathway may explain why anti-HIV cytotoxic cells are unable to clear this virus from the body. Strategies directed against the "recycling" of the retroviral genomes present in apoptotic debris may ultimately have a role in the treatment of HIV infection.