Expression of iCasp9M does not affect the phenotype or function of EBV-CTLs. Phenotype (A) and secretion (B) of Th1- and Th2-type cytokines upon antigen stimulation, and (C) cytolytic activity against autologous EBV-transformed lymphoblastoid B-cell line (LCL), HLA-mismatched LCL, and HSB-2 (a LAK cell target) were compared in nontransduced (□), F-Casp9M-transduced (▪), and F'F-C-Casp9C→S-transduced (▦) EBV-specific CTLs (EBV-CTLs) on day 15 to day 18 after transduction (2 antigenic stimulations after transduction). The mean and standard deviation of triplicate wells are shown. Examples of experiments using EBV-CTLs from 4 different donors are shown. *Greater than 5000 pg/mL. (D) On day 21 after transduction the normal weekly antigenic stimulation with autologous LCLs and IL-2 was continued (♦) or discontinued (▪) to evaluate the antigen dependence of iCasp9M-transduced CTLs.
