CTL-mediated LB lysis is perforin dependent.

Effect of CMA and SrCl₂ on cytotoxic activity displayed from antileukemia CTLs obtained from PBMCs of recipient patient 3 (▪), BMCs of donor patient 3 (▴), PBMCs of donor patient 3 (♦) after 3 stimulations, and a perforin-negative, EBV-specific CTL line (∗) (see “Results” for details). (A) CTL lines were incubated with CMA at a concentration of 1, 10, and 100 nM/L for 2 hours. (B) CTL lines were incubated with SrCl₂ at a concentration of 15, 25, and 50 mM/L for 18 hours. CTLs were then cocultured with ⁵¹Cr-labeled recipient LB or EBV-LCL for 8 hours at E/T ratios of 20:1, 10:1, and 5:1. The figure shows results from an E/T ratio of 5:1.