CEM-CAR cells eliminate Raji target cells. (A) Confocal images of Raji (CD19⁺) cells loaded with Calcein Red-AM (red, Raji Red) and CEM-CAR cells (green: sGFP-CD19-CAR, CEM-CAR) co-incubated for 3 h. (B) Mean fluorescence intensity of Calcein Red in Raji cells detected after 3 hour-incubation (Raji unlabeled: no Calcein Red-AM, Raji Red: only Raji cells, Raji Red + NT CEM: coincubation of Raji Red and NT CEM cells, Raji Red + CEM-CAR: coincubation of Raji Red and CEM-CAR T cells). (C) Mean fluorescence intensity of Calcein Red in MCF-7 and CD19 MCF-7 cells (CD19 MCF-7 unlabeled: no Calcein Red-AM, CD19 MCF-7 Red + 1% TritonX: CD19-MCF7 cells loaded with Calcein Red-AM, incubated with 1% TritonX, MCF-7 Red: only MCF-7 cells loaded with Calcein Red-AM, CD19 MCF-7 Red: only CD19 MCF-7 cells, CD19 MCF-7 Red + CEM NT: coincubation of CD19 MCF-7 Red and CEM NT cells, CD19 MCF-7 Red + CEM CAR: coincubation of CD19 MCF-7 Red and CEM CAR cells, MCF-7 Red + CEM CAR: MCF-7 Red coincubated with CEM CAR, MCF-7 Red + CEM NT: coincubation of MCF-7 Red and CEM NT cells. A symbol represents the mean intensity of Calcein Red determined for one cell. Horizontal lines: mean ± SEM; N ≥ 106 (Raji), 50 (MCF-7, CD19 MCF-7); ***P < 0.001, ****P < 0.0001.