Activated T lymphocytes generated from CLL patients are efficiently transduced with CAR-encoding retroviral vectors and have cytotoxic activity against CD23⁺ tumor cells. (A) Cytotoxic activity of NT, CD19.CAR⁺, and CD23.CAR⁺ T lymphocytes generated from CLL donors and tested against allogeneic LCL cells. Data represent the means ± SD for 5 different T-cell lines. *P ≤ .05 and **P ≤ .005 comparing CAR⁺ with NT T lymphocytes. (B) Dot-plot analysis of the coculture experiments in which CD23.CAR⁺ T cells derived from CLL patients were cocultured with allogeneic LCL cells in the absence or in the presence of different percentages of plasma enriched in soluble CD23. One representative experiment is shown. The numbers represent the percentage of residual CD19⁺ LCL cells (tumor cell line) enumerated by FACS analysis after 4 days of coculture. The experiment shown is representative of 3 different experiments. (C) Cytotoxic activity of NT, CD19.CAR⁺, and CD23.CAR⁺ T lymphocytes generated from CLL patients and tested against autologous CD23⁺ CLL cells. Data represent the means ± SD for 3 different T-cell lines. *P ≤ .05 comparing transduced and NT T lymphocytes. (D) Cytotoxic activity of NT, CD19.CAR⁺, and CD23.CAR⁺ T lymphocytes generated from CLL patients and tested against autologous CD23⁺ CLL cells using CFSE staining and cocultured for 24 hours. Data represent the means ± SD for 4 different T-cell lines. *P ≤ .05 comparing CAR⁺ transduced with NT T lymphocytes. (E) Cytotoxic activity of NT, CD19.CAR⁺, and CD23.CAR⁺ T lymphocytes generated from CLL patients and tested against allogeneic CD23⁺ CLL cells. Data represent the means ± SD for 3 different T-cell lines. *P ≤ .05 comparing transduced with NT T lymphocytes.