Identification of autoreactive T cells in Vogt-Koyanagi-Harada disease.

PURPOSE: To determine the finer specificity and immunologic features of autoreactive T cells in Vogt-Koyanagi-Harada (VKH) disease. METHODS: T-cell clones (TCCs ) specific to tyrosinase family proteins were raised from the peripheral blood mononuclear cells (PBMCs) of patients with VKH disease, and the response of the TCCs to 30-mer peptides was determined. The TCCs that were reactive to the peptides with strong binding sites for HLA DRB1*0405 were initially tested. Then, a finer specificity of these TCCs against 12- to 14-mer peptides was determined. The cytokine production of these clones was measured by ELISA. RESULTS: A total of 62 stable TCCs were established from the PBMCs of five patients with VKH (28 clones against tyrosinase, 34 clones against tyrosinase-related protein [TRP]1). Five of 28 TCCs for tyrosinase and 2 of 34 for TRP1 were reactive to the 30-mer peptides with strong binding sites for HLA DRB1*0405. These seven clones showed proliferative responses to one or more of the 12- to 14-mer peptides that match the motif of the strong binding site for HLADRB1*0405. Five of seven of the TCCs may be T-helper (Th) type 1, one of the remaining TCCs may be Th0, and the other may be Th2. CONCLUSIONS: The autoreactive T cells against tyrosinase and/or TRP1 may contribute to the development of VKH disease.