IFN-γ production and proliferation of Tax-specific CD8+ T-cells in HAM/TSP and cATL patients. (A) PBMCs from HAM/TSP and cATL patients were stimulated with or without 10 μM Tax peptide for 6 hrs. The number indicates the percentage of IFN-γ-producing cells in tetramer+ cells. (B) For CFSE-based T-cell proliferation, CFSE-labeled PBMCs from HAM/TSP and cATL patients were cultured in the presence or absence of 100 nM Tax peptide for 6 days. The number indicates the percentage of dividing (CFSElow) cells in tetramer+ cells. The percentage of tetramer+ cells among CD8+ T cells in fresh blood is indicated in parenthesis under the patient ID.