Fig. 6
From: CAR exosomes derived from effector CAR-T cells have potent antitumour effects and low toxicity
PD-L1 inhibits CAR-T cells but not CAR exosomes in vitro and in vivo. a Representative histogram of the expression of granzyme B (GzmB, red) and Ki-67 (blue) after the indicated treatments in CAR-T cells. The proportions of cells with positive GzmB or Ki-67 expression are shown on the right. b qPCR analyses of IL-2, IFN-γ, and TNF in CAR-T cells after the indicated treatments with or without blocking by recombinant PD-L1 or the anti-PD-L1 antibodies. The relative mRNA expression level was calculated as the ratio to the control cells. c ELISA of IL-2, IFN-γ, and TNF in CAR-T cells after the indicated treatment with or without blocking by recombinant PD-L1 or the anti-PD-L1 antibodies. d, e Killing activity of CAR-T cells (d) and CAR exosomes (e) in response to tumour cells. The cytotoxic activity of CAR-T or CAR exosomes against cancer cell lines was assessed by the 51Cr-release assay at the indicated effector-to-target (E:T) ratios or indicated concentrations with or without blocking by recombinant PD-L1 or anti-PD-L1 antibodies. f Tumour volumes of MDA-MB-231 (up) and SK-BR-3 (down) tumour xenografts after the indicated treatment (left, CAR-T cells; right CAR exosomes). n = 8. Arrows indicate the treatment point (f). Data are mean ± s.d. (a–e) of three (a) or six (b–e) independent biological replicates or means ± s.e.m. (e). P values are from a two-sided unpaired t test (a–c) or a two-way ANOVA followed by the Bonferroni post-test (d–f); Source data (a–f) are provided as a Source Data file
