Fig. 1
Characterization of HiCAR-T cells. a-f Effect of oxygen or CoCl2 levels on the CAR expression of HiCAR-T cells. AXL (a-b), CD19 (c-d) and HER2 (e-f). CAR-(e.g., AXL-BBz, CD19-z, HER2-BBz) or HiCAR (e.g., AXL-BBz-ODD, CD19-z-ODD, HER2-BBz-ODD)-engineered T cells were cultured under 21% O2, CoCl2 or 1% O2 for 24 h. g-j The impact of variations in oxygen levels on the cytolytic properties of HiCAR-T cells toward tumor cells expressing AXL (g), CD19 (h-i) or HER2 (j) was evaluated in a luciferase-based killing assay. CAR- or HiCAR-T cells were cocultured with tumor cells for 24 h at indicated E:T ratios. The results are displayed as the mean ± SEM of three independent experiments performed with three healthy donors. Significant differences between normoxia and hypoxia are indicated (*: p < 0.05, **: p < 0.01, ***: p < 0.001, ****: p < 0.0001, analyzed using a paired Student’s t-test). k-l Antitumor efficacy of HiCAR-T cells in vivo. The effects of CAR- or HiCAR-T cells on the growth of CD19-positive A549 tumor cells (k). The effects of CAR- or HiCAR-T cells on the growth of SKOV3 tumor cells expressing high levels of HER2. The tumor volumes at different time points are presented as the mean ± SEM (n = 5 mice/group), and the significant differences between CAR- or HiCAR-T cells and control T cells are indicated (****: p < 0.0001, analyzed using one-way ANOVA) (l)