Apoptosis: mechanisms and relation to AIDS.

Infection with the human immunodeficiency virus (HIV) is considered to lead to the acquired immunodeficiency syndrome (AIDS) via the progressive loss of immune competence in the infected host. Recent research has highlighted that HIV may indirectly trigger an active cell suicide process, referred to as programmed cell death or apoptosis, that contributes to the decline in lymphocyte counts throughout the course of HIV infection. We review here the main host- and HIV-related factors actively involved in inducing lymphocyte apoptosis. Among them, the relationships linking HIV, the oxidant/antioxidant balance in the cellular redox system, tumor necrosis factor (TNF) and lymphocyte-associated ceramide generated through the activation of sphingomyelin pathway are receiving growing consideration. Recognizing the importance of apoptosis in AIDS pathogenesis may have a great impact on the design of new strategies for the treatment of the disease. Available data indicate that antioxidant compounds exert antiapoptotic activity. These compounds, in our opinion, should be used in combination regimens with antiretroviral drugs in the treatment of HIV-infected subjects.