NY-ESO-1–specific CD8⁺ T cells are detected in ATLL patients. CD8⁺ T cells derived from PBMCs of patients 1, 2, 4, 8, 13, 14, 19, 27, and 43 were presensitized by CD4⁻ CD8⁻ PBMCs pulsed with NY-ESO-1 peptides covering the entire sequence of NY-ESO-1 as described in “In vitro sensitization.” (A) Induction of specific CD8⁺ T cells was analyzed by staining with NY-ESO-1/HLA tetramers indicated. Cytokine (IFN-γ and TNF-α) secreting capacity of NY-ESO-1–specific CD8⁺ T cells was analyzed by intracellular cytokine staining for recognition of (B) autologous activated T-cell APCs pulsed with NY-ESO-1 peptides or (C) autologous ATLL cells. These experiments were performed independently at least twice with similar results.