CD58-deficient tumors show decreased sensitivity to CAR T-cell therapy in mouse xenograft model. (A) Schematic showing the generation of xenograft mouse models. NPG mice (n = 6 per group) were injected IV with 1 × 10⁵ WT or CD58^KO Nalm6-luk cells 7 days after a single IV injection of 1 × 10⁶ control T cells or CD19 CAR T cells. Tumor burden was monitored every 7 days with BLI with an IVIS imaging system. (B) IVIS-obtained images showing tumor burden; BLI was performed at the indicated time points. (C) Average radiance measurement at the indicated time points (n = 6). (D) Mouse survival was monitored and recorded (n = 6 per group). (E) T-cell persistence in peripheral blood on days 7 and 14 (n = 6). (F) FACS-based measurement of CD25 expression in CD19 CAR T cells in peripheral blood on days 7 (n = 6). (G) Cytokines in peripheral blood at 7 days after CAR T-cell infusion were measured by enzyme-linked immunosorbent assays (n = 6). Significance was assessed using a 2-way ANOVA with multiple comparisons in panels C and E. Log-rank tests were performed to assess the significance of difference in panel D. Statistical comparisons were performed using a 2-tailed unpaired t test in panel F. Statistical comparisons were performed using a 1-way ANOVA test in panel G. The values are shown as the means plus or minus SD of 6 mice per group. For panels B-G, the results were from 1 of 3 independent experiments. ∗P < .05; ∗∗P < .01; ∗∗∗P < .001. FACS, fluorescence-activated cell sorter; MFI, median fluorescence intensity; ns, not significant (P > .05).