Fig. 7

CAR exosomes do not cause cytokine release syndrome in mice. a Killing activity of CAR-T-T1E cells in response to tumour cells. The cytotoxic activity of CAR-T-T1E and control T cells against cancer cell lines was assessed by the ⁵¹Cr-release assay at the indicated effector-to-target (E:T) ratios. b Tumour volumes of MDA-MB-231 tumour xenografts after the indicated treatment, n = 8. c ELISA (left) of CAR on exosomes from CAR-T-T1E and transmission electron micrographs of CAR-EXO-T1E (right). Scale bars = 100 nm. d Cytotoxic activity of CAR exosomes and control T cells against cancer cell lines was assessed by the ⁵¹Cr-release assay at the indicated concentration. e Tumour volumes of MDA-MB-231 tumour xenografts after the indicated treatment, n = 8. Arrows indicate the treatment point (e). f Three groups of three tumour-free mice were treated i.p. with CAR-T-T1E cells at the indicated escalating doses. Serial weight measurements were performed and normalized to the starting body weight for each animal. The Kaplan–Meier survival curve of mice in all three groups is shown on the right. g Serum levels of human (h) and mouse (m) cytokines, measured at the indicated time points. h Three groups of three tumour-free mice were treated i.p. with CAR-EXO-T1E cells at the indicated escalating doses. Serial weight measurements were performed and normalized to the starting body weight for each animal. The Kaplan–Meier survival curve of mice in all three groups is shown on the right. i Serum levels of human (h) and mouse (m) cytokines, measured at the indicated time points. Arrows (b, e) indicate the treatment point. Results shown represent three (c) independent experiments. The data are presented as the means ± s.d. of six (a); four (c) or three (f–i) independent biological replicates or means ± s.e.m. three (f–i) independent biological replicates. P values are from a nonparametric t test (a, b, d, e) or a two-sided unpaired t test (c). Source data (a–i) are provided as a Source Data file