RECEPTORS ON T-CELLS ESCAPING SUPERANTIGEN-MEDIATED DELETION LACK SPECIAL BETA-CHAIN FUNCTIONAL REGION STRUCTURAL CHARACTERISTICS

The TCR V beta element is pivotal for superantigen recognition; howeve r, not all T cells bearing a particular V beta element respond to an i ndividual superantigen, Recent evidence has indicated that the TCR V a lpha element also contributes to recognition of superantigen/MHC class II complexes, To determine whether the TCR beta-chain junctional regi ons influence recognition of a superantigen encoded by mouse mammary t umor virus (MMTV) proviral integrant Mtv-1, we have analyzed these reg ions in T cells that have survived superantigen-mediated negative sele ction in B10.BR-Mtv-1 mice. Our data indicate: 1) no TCR J beta skewin g, 2) no difference in the length of the third complementarity-determi ning region (CDR3), and 3) no outstanding structural features that are shared among the junctional regions of the V beta 3(+) T cells that e scape thymic clonal elimination in superantigen-expressing mice. Sever al possible models for TCR engagement of viral superantigen/MHC class II complexes are discussed.