Fig. 3: CAR-modified PMs exhibited antigen-specific cytotoxicity against GC cells in vitro.

a Fluorescence of MKN45 cells at different effector-target ratio (macrophage:tumour = 10:1, 5:1, 2:1, 1:1, 1:2, 1:5, 1:10) was detected by spectrophotometer. Assessment of tumour cell killing using MKN45 cells alone as a baseline. b Phagocytosis of GFP-positive macrophages co-cultured with DiR-labelled MKN45 cells. c Apoptosis-related protein expression in MKN45 cells co-cultured with HF-CAR-PMs and HG-CAR-PMs. d Expression of inflammatory factors after co-culture of MKN45 gastric cancer cells with HF-CAR-PMs and HG-CAR-PMs. e Annexin V/PI staining for assessment of MKN45 cell apoptosis in HF-CAR-PMs and HG-CAR-PMs treatment. f Microscopic image of MKN45 tumour spheres. g Microscopic image of GFP labelled HF-CAR-PMs on MKN45 tumour spheres. h Infiltration of GFP labelled HF-CAR-PMs in tumour spheres at different effector/target ratio (macrophage:tumour = 1:3, 1:1, 3:1). The fluorescence intensity was quantified by Image J. i Tumor cell killing activity of HF-CAR-PMs and HG-CAR-PMs derived from other two donors. (Statistical analysis was performed by Student’s t test when only two value sets were compared. One-way ANOVA followed by Dunnett’s test was used when the data involved three or more groups).