Autoantigen-recognition of EBNA1-specific T cells. Cross-reactivity of EBNA1-specific T cells to myelin antigens or proinsulin was analyzed. (A) Frequencies of EBNA1-specific TCLs generated from 6 patients with MS and 6 healthy EBV carriers recognizing peptides of myelin antigens or proinsulin. *, P = 0.01. (B) Frequencies of autoantigen-recognizing EBNA1-specific T cells in MS patients compared with healthy virus carriers. (C) Stimulation indices (SI) after EBNA1 stimulation of EBNA1-monospecific, EBNA1-specific myelin-reactive, and EBNA1-specific insulin-reactive T cells in patients and controls. (D) Serological clonality analysis by flow cytometric staining for TCR-Vβ3, 1, 5S1, 2, 5S2, 5S3, 6S7, 7, 8, 9, 11, 13S1, 12, 13S6, 16, 14, 17, 18, 1S3, 20, 22, and 23. Depicted are the results for one representative TCR Vβ3⁺ CD4⁺ T cell clone. (E) Cytokine profile of cross-reactive versus monospecific EBNA1-specific T cells. IL-2: *, P < 0.0001. MIP-1β: *, P = 0.02. Error bars represent the SD.