Fig. 1

The absence of B7-H4 is essential for tumor cells to escape from cytotoxic T cells. A, B The cytotoxic effect of B7-H4 CAR-T cells and non-specifically activated T cells on CFSE labeled SKBR3 cells at the indicated effector/target (E/T) ratios. The residual living SKBR3 cells were imaged by microscopy (A) and the cytolytic percentages were calculated in the killing assay (B). Scale bar = 50 μm. C A schematic co-cultured transwell model presents simulating T cell-mediated cytotoxicity in TIME. D T cell-induced escape of CFSE-labeled SKBR3 cells into the lower chamber was observed by microscopy (left graph) and quantified by flow cytometry analysis (right graph). Scale bar = 100 μm. E B7-H4 expression levels of SKBR3 cells in the lower chamber of different groups were quantified by flow cytometry analysis. F–H B7-H4 expression levels of residual living SKBR3 cells were analyzed by flow cytometry (F), qPCR (G) and western blot (H) after co-culture with non-specific activated T cells and B7-H4 CAR-T cells, respectively. The data represent the mean ± SEM from three independent experiments, and statistical significance was determined by two-tailed unpaired t test (B) or one-way ANOVA (D–H). Ta: activated T cells. (*p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001)