Cytotoxic activity of 4 p540-specific CTL lines generated from patients 2, 11, 16, and 18 against autologous primary prostate cancer cell lines. Percentages of tetramer-positive cells in the different CTL lines were 15%, 18%, 25%, and 20%, respectively. Effector-target ratio was 40:1. The analyses were performed in the absence of mAb (A, D, G, L), and in the presence of either the anti–HLA class I W6/32 mAb (10 μg/mL) (B, E, H, M) or an unrelated isotype-matched control mAb (C, F, I, N).