Fig. 2

Single base conversion reduced PD-1-mediated suppression. a IFN-γ (100 IU/mL) induced PD-L1 expression in target cells. After that, target cells were washed to discard IFN-γ and used in following experiments. b–d CAR-T cells were co-incubated with target cells without exogenous cytokines. b CAR-T cells expanded with or without target cells for 48 h. c CAR-T cells were co-cultured with target cells at indicated effector to target ratios (E:T) for 24 h. The cytolytic potencies of CAR-T cells were tested using bioluminescence imaging. d CAR-T cells were incubated with tumor cells at E:T = 1:1. Twenty-four hour later, IL-2 and IFN-γ in supernatants were detected using ELISA. e–j The anti-tumor effects of ABE-edited CAR-T cells in vivo. e Five days after infusion, the ratios of infiltrated T cells (CD45⁺CD3⁺) were determined using flow cytometry after excluding dead cells (n = 4 per group). f, g The expressions of PD-1, CD69, and CD27 were detected in infiltrated T cells. In addition, effects of CAR-T cells on tumor growth (h, i) and survival of mice (j) were monitored weekly (each group had 5 mice). *P < 0.05 and **P < 0.01