Fig. 5: Bias of TRAV6⁺ TCR recognition toward HLA-DR4^{Vim-64cit59-71} and HLA-DR4^{Fibβ-74cit69-81}.

a TRAV CDR loop sequences of M134 TCR and A03 TCR. Detailed interactions between CDR α loops of TRAV6⁺ (b) A03 TCR and (c) M134 TCR docking on top of the antigen binding cleft at P2 of the epitope. The HLA-DR4 α- and β-chains are coloured in white and brown, respectively, Vim-64cit^59–71 peptide coloured is coloured in pink and Fibrinogen β-74cit^69–81 peptide is coloured in yellow. d Effect of A03 TCR point mutations at the pHLA interface. The Y-axis represents the fold of affinity of mutant TCRs as compared with wild-type TCR. The X-axis represents the position of A03 TCR mutants. e Effect of HLA-DR4 mutations on A03 TCR binding affinity. The Y-axis represents the fold change in affinity of mutant TCRs with respect to the wild type A03 TCR and the X-axis represents the position of HLA-DR4 residues mutation. The SPR experiments were performed in duplicate (n = 2). The impact of each mutation was classified as negligible (\(\le\) 1-fold affinity decrease, blue), mild (1.5-fold to 3-fold affinity decrease, green), moderate (3-fold to 5-fold affinity reduction, orange), or critical (>5-fold affinity decrease or no binding, red) shown on graph and on surface of pHLA. Source data are provided as a Source Data file.