T-CELL RESPONSE TO STAPHYLOCOCCAL SUPERANTIGENS BY ASYMPTOMATIC HIV-INFECTED INDIVIDUALS EXHIBITS SELECTIVE CHANGES IN T-CELL RECEPTOR V(BETA)-CHAIN USAGE

Recognition that the murine mammary tumor C-type retrovirus and the replication-defective murine leukemia virus have ''superantigen'' properties raises the specter that human immunodeficiency virus might also generate T cell impairment and destruction as a result of inherent superantigen properties. The observation that individuals with AIDS lack the expression of several T cell receptor V(beta)-chain genes lends support to this hypothesis. Staphylococcal exotoxins represent another class of superantigen with a similar ability to stimulate large numbers of T cells bearing specific T cell receptor V(beta)-chain types. To examine the hypothesis that T cells from HIV-infected individuals may be exposed to a superantigen during the infection process, we have compared the ability of T cells from asymptomatic HIV-infected donors and healthy donors to respond to stimulation with several known staphylococcal exotoxin superantigens. Following in vitro stimulation with staphylococcal enterotoxin D and staphylococcal enterotoxin E, asymptomatic HIV-infected individuals responded with a significantly different T cell receptor V(beta)-chain usage to that observed for healthy individuals. This skewed V(beta)-chain usage is likely to reflect preferential conditioning of T cells bearing specific V(beta)-chains as a result of HIV infection, supporting the hypothesis of superantigen involvement early in the course of infection.