CD4⁺ T cells stimulated with HSV-pDCs exhibit perforin-dependent cytotoxicity. (A) Naive CD4⁺ T cells stimulated with the 3 types of allogeneic DCs for 8 days (effector cells) were cocultured with CFSE-labeled Daudi target cells at an E/T ratio of 10:1 or 2.5:1 for 4 hours. Immediately before analysis, 7-AAD was added to each sample, and percentages of 7-AAD⁺ cells were analyzed by flow cytometry. Basal lysis of the target cells was 9.6%. The data shown are representative of 2 experiments. (B) Naive CD4⁺ T cells stimulated with the 3 types of allogeneic DCs for 8 days (effector cells) were cocultured with CFSE-labeled Daudi target cells at an E/T ratio of 30:1 for 4 hours in the absence or presence of EGTA. Percentages of 7-AAD⁺ cells were analyzed by flow cytometry as shown in panel A. Basal lysis of the target cells was 18%. Filled and open bars represent percent specific lysis induced in the absence or presence of EGTA, respectively. The data shown are representative of 3 experiments. (C) Naive CD4⁺ T cells stimulated with the 3 types of allogeneic DCs for 8 days (effector cells) were cocultured with CFSE-labeled activated T cells from third-party donors (target cells) at an E/T ratio of 30:1 for 4 hours. Percentages of 7-AAD⁺ cells were analyzed by flow cytometry as shown in panel A. Basal lysis of the target cells was 16%. The data shown are representative of 2 experiments.