HIV INDUCES ACTIVATION OF PHOSPHATIDYLINOSITOL 4-KINASE AND MITOGEN-ACTIVATED PROTEIN-KINASE BY INTERACTING WITH T-CELL CD4 SURFACE MOLECULES

T cell surface CD4 molecules act as co-receptors that amplify the T ce ll receptor (TcR)/CD3-induced signal transduction by a mechanism that requires the interaction of CD4 with p56(lck) tyrosine kinase (Veillet te et al.; Nature 1989, 338: 257). Here, we demonstrate that in the ab sence of TcR signaling, heat-inactivated HIV-1 (HIV-HI) also elicits a cascade of events generally considered to convey a positive signal, s uch as protein tyrosine phosphorylation, phosphatidylinositol 4-kinase and mitogen-activated protein kinase activation. These results contri bute to understand better the control that HIV may exert on its own re plication or on T cell apoptosis by modulating the activation status o f its target cells through its interaction with T cell surface CD4 mol ecules.