Figure 4.

Tan(S)-CAR T cells eliminate primary and PDX B-ALL cells in vitro

(A and B) CD22 and CD19 FACS expression in primary B-ALL blasts (n = 3) (A) and B-ALL PDX cells (n = 3) (B). (C and D) Absolute number of live primary B-ALL blasts (C) and B-ALL PDX cells (D) after 24-h incubation with the indicated CAR T cells at 2:1 E:T ratio. (E and F) Production of the pro-inflammatory cytokines IL-2, IFN-γ, and TNF-α by the indicated CAR T cells after 24-h exposure to either primary B-ALL blasts (E) or B-ALL PDX cells (F) at 2:1 E:T ratio. PBMCs from n = 3 independent HDs. (G) Absolute number of live T cells after 24-h incubation with the indicated primary B-ALL blasts or B-ALL PDX cells at 2:1 E:T ratio. (H and I) Autologous cytotoxicity experiment. Representative FACS plots of CAR T cells produced from MACS-sorted T cells from the PB of a B-ALL patient (Pt #4) showing the transduction efficiency at day 6 (H). Absolute number of live SEM cells (left panel) or live primary B-ALL blasts from the same patient (patient 4) after 24-h incubation with the Tan(S)-CAR T cells at 2:1 E:T ratio (I). Data are shown as means ± SEMs. ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001; 2-way ANOVA with the Tukey post hoc test.