Evidence for a viral superantigen in humans

Abstract

SUPERANTIGENS1–4 bind class II major histocompatibility pro-teins5,6 and stimulate powerful proliferative responses of T lymphocytes bearing particular Vβ sequences as part of their αβ antigen receptor7. Exogenous bacterial superantigens are respon-sible for food poisoning and toxic shock syndrome. Murine virus-encoded self-superantigens induce clonal deletion of T lym-phocytes. Although superantigen-like properties have been suggested for human immunodeficiency virus-1, no viral superantigen has been identified in humans8. Here we report that the nucleocapsid of the rabies virus is an exogenous superantigen specific for Vβ8 human T lymphocytes which binds to HLA class II α-chains.