Fig. 2: BBζ and BBε CARs induce stronger T cell activation on antigen encounter.
a, Expression of activation markers by CAR T cells after 24 h of stimulation with Nalm6 (1:1 ratio) (n = 4). b, Phenotype of CAR T cells after 48 h of stimulation with Nalm6 (1:1 ratio) (n = 6). TCM, T central memory cells; TEM, T effector memory cells; TEMRA, T effector memory cells re-expressing CD45RA. c, Cytokines secreted by CAR T cells after 24 h of stimulation with Nalm6 (1:1 ratio) evaluated by ELISA (n = 4). d, Endogenous TCR–CD3 surface expression after 24 h of stimulation with Nalm6 (1:1 ratio) (n = 4). e, Schematic representation of an SLB featuring fluorescently labeled CD19 antigen, the adhesion molecule ICAM-1 (intercellular adhesion molecule 1) and the costimulatory molecule B7.1 for recognition by CAR T cells. LFA-1, Lymphocyte function-associated antigen 1. f, Percentage of cells fluxing calcium on encountering CD19 at the indicated densities. Data represent three independent experiments done with three independent donors. g,h, Flow cytometry analysis of degranulation assayed by upregulation of CD107a in response to CD19+ Nalm6 contact for 4 h (g) and 8 h (h). Shown are representative dot plots (4 h) and statistical analysis (n = 4). BFP, blue fluorescent protein. i, Specific killing of CD19+ Nalm6 cells by primary human CAR T cells (1:1 ratio) for 12 h in the presence of the indicated blocking antibodies (n = 4). Specific killing was normalized to isotype control (100%). Two independent anti-Fas antibodies were used and the results pooled (n = 4 healthy donors, 6 independent cocultures). Each dot represents an independent donor (n). Data are represented as mean ± s.d. One-way (a, c and d) or two-way (b and g–i) ANOVA followed by Dunnett’s (b and i) or Sidak’s (g and h) multiple-comparison test was used.
