Molecular mechanisms of APO-1/Fas(CD95)-mediated apoptosis in tolerance and AIDS.

The cell surface molecule APO-1/Fas(CD95), a member of the Tumor Necrosis Factor (TNF) receptor/Nerve Growth Factor (NGF) receptor superfamily mediates apoptosis upon cross-linking by agonistic antibodies or its ligand. Recent findings suggest that APO-1/Fas(CD95) and its ligand are the key molecules for antigen receptor-induced apoptosis in activated mature T cells. Here we propose a mechanism for antigen receptor-induced apoptosis of activated T cells via APO-1 ligand mediated autocrine suicide. This mechanism may also contribute to the depletion of CD4+ T cells in AIDS.