COMPARISON OF TCR‐αβ SEQUENCES OF CROSS‐REACTIVE ANTI‐DR ALLOREACTIVE T‐CELL CLONES: IDENTIFICATION OF POSSIBLE CONTACT RESIDUES BASED ON CHARGE COMPLEMENTARITY BETWEEN TCR CHAINS AND DR DETERMINANTS

We analysed alloreactive T-cell clones selected for their differential recognition of DR variants differing in the third hypervariable region (hvr) of the DRB1 gene (amino acid positions 67-70-71). This polymorphism leads to two main hvr3 types : a basic form (Leu 67 -Gln 70 -Arg/Lys 71 ) and an acidic form (Ile 67 -Asp 70 -Glu 71 ) where residue 70 is probably directly accessible to the TCR on DRβ chains. The TCRs have been sequenced. Three DRw13-reactive clones use similar Vα2 and Bβ13 gene family members but differ mainly by their cross-reactivity towards acidic or basic DR4 variants and by the sequence of CDR3 on their TCRα and/or β chains