Comparisons of self-restricted and allo-restricted CTLs. (A-B) The cytotoxic activity of individual CTL was measured against T2 cells loaded with graded amounts of tyrosinase peptide (10⁻¹¹ M to 10⁻⁵ M) at an E:T of 10:1. Peptide concentration and percentage relative lysis are displayed on the x- and y-axes, respectively. Shown are (A) patient-derived CTL IVS-B (♦°), CTL Tyr-F8 derived via T2 peptide priming (▲°), and the 5 DC-primed self-restricted CTL and (B) DC-primed allo-restricted CTL. Bold lines represent CTL D115 and T58 in panels A and B, respectively. (C) Relative values of half-maximal lysis are presented for CTL IVS-B, Tyr-F8, self-restricted CTLs (n = 5), and allo-restricted CTLs (n = 7). Means are represented as black bars. Significant differences were found between the 2 groups (nonparametric Mann-Whitney U test; *P < .05).