HIV envelope glycoprotein, antigen specific T-cell responses, and soluble CD4.

Specific T cells stimulated by antigen presenting cells (APC) pulsed with antigen in the presence of HIV were no longer detectable with a functional assay, which suggests that HIV has been transferred from APC to the specific activated T cell via an antigen-dependent mechanism to exert its cytopathic effect on activated T cells. In contrast soluble gp120 inhibited antigen-driven proliferation, but this action was reversible and could be blocked by soluble CD4. Thus the chief mechanism of HIV pathogenesis may be gp120/CD4 interaction and HIV may be pathogenic mainly as a producer of gp120.