AMINO-ACID SUBSTITUTIONS IN THE FLOOR OF THE PUTATIVE ANTIGEN-BINDINGSITE OF H-2T22 AFFECT RECOGNITION BY A GAMMA-DELTA-T-CELL RECEPTOR

We have previously identified a self-reactive gammadelta T-cell clone (KN6) specific for the H-2T region gene product T22b. Now we have inve stigated by an in vitro mutagenesis analysis of the 722b gene the poss ibility that the interaction between the KN6 gammadelta T-cell recepto r and T22b involves a peptide. The results demonstrate that mutations at the floor of the putative antigen-binding groove of T22b affect rec ognition by the gammadelta T-cell receptor. Furthermore, we have shown that KN6 cells react with cells that are deficient in the class I pep tide transporter TAP1/TAP2. These results suggest that peptide is invo lved in the interaction of the KN6 T-cell receptor with T22 and that l oading of T22 with the putative peptide is TAP1/TAP2-independent.