Apoptosis in HIV-1 infection.

Apoptosis is a key event in biologic homeostasis with particular importance to the immune system. It is an active energy-dependent process that is tightly regulated and controlled by a variety of signal transduction pathways. Apoptosis modulation plays a part in the pathogenesis of many human diseases, including HIV infection. Although multiple mechanisms may contribute to the decline in CD4 T-lymphocyte numbers observed, apoptosis is a significant factor. Alterations in levels of apoptosis are observed in both directly infected and uninfected bystander cells and a variety of pathways of apoptosis induction have been implicated. Apoptosis induction is related to death receptor and mitochondrial-induced pathways in specific circumstances. These events have been linked to individual HIV proteins and have been demonstrated to be altered by antiretroviral therapy.