The Jβ segment of the T cell receptor contributes to the Vβ‐specific T cell expansion caused by staphylococcal enterotoxin B and Urtica dioica superantigens

Abstract We have used a new polymerase chain reaction‐based technique to analyze at the clonal level the CDR3 diversity and the Jβ usage associated with the Vβ‐dependent T cell receptor (TCR) recognition of two superantigens: the staphylococcal enterotoxin B and the Urtica dioica agglutinin. Our results show that a subset of Jβ elements is preferentially expanded in a given Vβ family, independently of the nature of the superantigen. By contrast, the CDR3 loop does not contribute significantly to the T cell expansion induced by the superantigens. We conclude that the Jβ segment of the TCR β chain, but not the CDR3 region, participates in superantigen binding, presumably by influencing the quaternary structure of the TCR β chain.