Antigen contact sites in class I major histocompatibility complex-restricted, trinitrophenyl-specific T cell receptors

✍ Scribed by Hans Ulrich Weltzien; Sabine Hebbelmann; Ulrike Pflugfelder; Helga Ruh; Bodo Ortmann; Stefan Martin; Antonio Iglesias

• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 376 KB
• Volume: 22
• Category: Article
• ISSN: 0014-2980
• DOI: 10.1002/eji.1830220335

✦ Synopsis

Abstract

Cloned trinitrophenyl (TNP)‐specific cytotoxic T cells (CTL) were obtained from mice transgenic for the β chain of the antigen‐specific receptor (TcR) of a K^b^‐restricted, TNP‐specific CTL clone (BT7.4.1). The transgene‐expressing CTL, specific for TNP/K^b^ were found to select for TcR α chains highly similar to that of the transgene donor clone BT7.4.1. In that way, two clones (II/7 and III/1) were identified whose TcR differed from the BT7.4.1 receptor only in their N~α~‐ and J~α~‐sequences, i.e. within the third complementarity‐determining regions of their α chains (CDR3~α~). Moreover, the TcR of clones II/7 and III/1 had both rearranged the same J~α~ element, thus differing from each other by only two amino acids in their V~α~/J~α~ junctional regions. Functionally, however, clone III/1 exhibited unique cytolytic specificities for synthetic, K^b^‐binding TNP‐peptides as well as for chemically TNP‐modified allogeneic (H‐2^k^) target cells. These findings demonstrate that (a) similar to “conventional” peptide antigens, synthetic hapten‐peptide determinants are contacted by CDR3~α~‐determined amino acids of the TcR and (b) in contrast to current models, CDR~α~ also appears to influence the major histocompatibility complex restriction specificity of a given TcR.