The HIV glycoprotein gp 160 has superantigen-like properties

HIV infection is characterized by paralysis of the immune system and a depletion of CD4+ cells. Recent studies demonstrating modulation of the V beta T cell receptor (TCR) repertoire in HIV patients have suggested that some of these effects may be the result of action by one or more superantigens encoded by the virus. In order to determine whether the HIV envelope glycoprotein, gp160, displays properties reminiscent of a superantigen, the T cell receptor V beta repertoire of T cells from healthy, seronegative individuals activated in vitro with gp160 was determined. In five individuals of disparate HLA type, activation by gp160 resulted in a marked skewing in the relative expression of a common set of V beta gene segments. This activation was HLA class II-dependent and did not require antigen processing. Surprisingly, the V beta segments affected by gp160 bore a striking similarity to those affected by the staphylococcal superantigen SEB. These observations suggest that exposure to superantigens produced by opportunistic infection might play an important role in disease progression.