gp120-induced programmed cell death in recently activated T cells without subsequent ligation of the T cell receptor

In most individuals, HIV infection is characterized by a progressive decline in the number of peripheral blood CD4⁺ T lymphocytes, and while the number of CD4⁺ cells is within the normal range, defects in immune function are detectable. To date neither the decline in function nor the decline in cell number have been satisfactorily explained. Here we describe a mechanism which may contribute to the immunodeficiency and decline in CD4⁺ cell numbers in HIV-infected individuals. We show that recently activated T cells are susceptible to apoptosis when exposed to HIV gp120 in the presence of anti-gp120 antibody.