Fig. 2: The disruptive targeted insertion of HLA-E at the B2M locus does not affect the antitumor activity of ΔTRAC_CARΔB2M_HLAE.

a, b Antitumor activity of engineered T cells in vitro. T cells edited as indicated and expressing a CAR specific for either CD22 (a) or CD123 (b) were co-cultivated in vitro, with nano-luciferase-expressing RAJI or MOLM13 leukemia cell lines, respectively, using variable effector to target (E/T) ratios. The nano-luciferase signal obtained after co-culture was normalized to the one obtained for tumor cells fully depleted by Zwittergent^® to determine the frequency of tumor cells lysis. On each box plot, the central mark indicates the median, the bottom and top edges of the box indicate the interquartile range (IQR), and the whiskers represent the maximum and minimum data point. Each point represents one experiment performed with a given T-cell donor (n = 3 biological replicate for CAR T-cell specific for CD22 and CD123, n = 3 and n = 1 technical replicates for CAR T-cell-specific CD22 and CD123, respectively). p-values are documented in the source file for clarity. c Schematic showing the experimental design to investigate the antitumor activity of ΔTRAC_CAR123ΔB2M_HLAE in the xenograft mouse model. Immunodeficient NSG mice were adoptively transferred with MOLM13-Luc-GFP leukemia cells (2.5 × 10⁵ cells/mouse in 100 μL of PBS via i.v.). On day 7, leukemia-bearing mice were adoptively transferred (i.v.) to randomized mice with mock-transduced T cells (n = 7), ΔTRAC_CAR123T cells (n = 7), ΔTRAC_CAR123ΔB2M T cells (n = 9), ΔTRAC_CAR123ΔB2M_HLAE T cells (n = 9) or no T cells (n = 8) (7 × 10⁶ viable CAR⁺ cells/mouse in 100 μL of PBS via i.v. injection). Mice were monitored and followed for overall survival. d Kaplan–Meier plot obtained for different mouse cohorts. Log-rank (Mantel–Cox) tests were used for statistical analysis. P values are indicated on the figures. Source data are provided as a Source Data file.