DIRECT INVOLVEMENT OF EXTRACELLULAR HIV-1 VIRIONS IN THE APOPTOSIS OFCD8- A 2-STEP MODEL( LYMPHOCYTES )

Lymphocytes of the CD8 phenotype play an important role in controlling viral burden in HIV-1 infection. Cytotoxic CD8+ T lymphocytes (CIL) c an kill HIV-infected cells and in addition, are able to secrete a solu ble factor that inhibits HIV replication. In most cases, HIV-infected individuals experience an unexplained CD8+ lymphopenia during the adva nced stage of the disease that particularly affect HIV-1-specific CTL. It has been reported that CD8+ lymphocytes in HIV-infected individual s undergo programmed cell death or apoptosis. We now present a two-ste p model to explain CD8+ apoptosis, based on anchorage of HIV-1-associa ted MHC class 1 antigen into the envelope of extracellular viral parti cles.