DM sensitivity is determined by the T-cell epitope. (A) Schematic overview of wild-type proteins PI4K2B and PTK2B (left) and proteins with exchanged T-cell epitopes (right). T-cell epitopes are indicated by the hatched areas. (B) T-cell recognition in IFN-γ ELISA is shown for the 2 wild-type PI4K2B and PTK2B antigens (left) and proteins with exchanged T-cell epitopes (right) after retroviral transduction into HeLa variants cotransduced with DRB3*0101/DRA*0102 (top) and DQB1*0603/DQA*0103 (bottom), respectively. Mean ± SD release of IFN-γ of duplicate wells on coincubation with the specific CD4⁺ T-cell clones is shown.