Extended Data Fig. 5. CAR4 T cells induce upregulation of ICAM-1 and PD-L1 molecules on both immune and tumor cells in the tumor microenvironment.
Pro-B-cell tumors were established by intravenous injection of 0.5 × 106 pro-B-DEVD cells in C57BL/6 mice after sublethal irradiation. Six days later, mice were injected intravenously with WT or IFN-γ−/− CAR4 T cells (5–10 × 106). (a–b) CAR4 T cell-derived IFN-γ induces ICAM-1 and PD-L1 upregulation in both tumor and tumor-infiltrating immune cells. Bone marrow cells were analyzed using flow cytometry 3 days after CAR T cell transfer. Surface expression of ICAM-1 and PD-L1 was assessed on CD11b+ myeloid (A) and tumor cells (B). gMFI, geometric mean fluorescence intensity. Each dot represents one mouse (n = 10 untreated and n = 11 WT CAR4 T cell-treated mice from n = 3 independent experiments, n = 8 IFN-γ−/− CAR4 T cell-treated mice from n = 2 independent experiments). One-way ANOVA and Tukey’s multiple comparisons were used for statistical analysis. Data are expressed as mean ± SEM. ***P<0.001; **P<0.01; *P<0.05; ns, not significant.