Fig. 5

h1218-CART19 demonstrates lower avidity and less activation-induced cell death than FMC63-CART19. A Quantification of UTD, FMC63-CART19, and h1218-CART19 binding avidity to Nalm6 after 15-min co-culture (n = 2 donors) by Lumicks analysis. B Representative confocal microscopy images of F-actin, CD19, perforin, and phosphorylated-CD3ζ (pCD3ζ) (CAR) expressed in FMC63-CART19 or h1218-CART19 cells when engaged with biotinylated CD19 protein. C Quantification of F-actin, perforin polarization, and pCD3ζ in FMC63-CART19 or h1219-CART19 cells engaged with biotinylated CD19 protein (n = 2 donors). In total, 200 events were recorded for each group. D (Left) Representative flow cytometric analysis of Caspase3/7 ⁺ FMC63-CART19 and h1218-CART19 cells with and without 4-h stimulation by Nalm6. Caspase3/7 ⁺ population of CART19 cells is boxed in red. (Middle) Baseline level of Caspase3/7⁺ population in FMC63- or h1218-CART19 cells at 0 h. (Right) Differential increase in the Caspase3/7⁺ population after 4-h stimulation. All graphs are represented as the mean ± SEM. Student's t-test was used to compare two groups; one-way ANOVA was performed with Tukey’s correction for multiple comparisons; **** p < 0.0001, *** p < 0.001, ** p < 0.01, and * p < 0.05. All bar graphs are presented as the mean ± SEM. All experiments were repeated at least twice