Fig. 8. Enhanced in vivo antitumour function and reduced exhaustion of dCAR T cells.

a Representative histograms showing the percentage of CAR T cells in the PB at the indicated time points are presented and were used to evaluate the in vivo expansion of CAR T cells. b The CAR gene number from PB samples taken from mice-bearing tumours from Raji cells treated with 1 × 10⁶ CAR T cells in each group collected at serial time points after cell infusion was measured by Q-PCR using primers specific for the transgene (n = 4 mice over two independent experiments). c Cytokines from the sera of venous blood samples from mice from ALL model experiments (n = 4 mice over two independent experiments) collected at 14 days after cell infusion were measured by FACS. All data are the fold change in the value measured in the test group compared to that in the control group. Colours indicate fold changes of cytokine levels. d Upper panel: Mice-bearing tumours from Raji cells treated with 1 × 10⁶ CAR T cells were sacrificed on day 14 after treatment. Paraffin tumour sections were stained with CAR scFv-, granzyme B- (GZMB-), IFN-γ- and FasL-specific probes for RNA ISH. Scale bar: 100 μm. Lower panel: The positive cell count value is the mean value from ten randomly selected fields in each slice (five slices from three mice in two independent experiments). e Upper panel: Statistical analysis of differences in the ratio of cells expressing the non, 1, 2 or 3 phenotypes (PD1, LAG3 and TIM3) of the CAR T cells. Lower panel: Expression of PD1, LAG3 and TIM3 in CAR T cells. f Expression of CD3/CD62L and CD3/CD25 on CAR T cells. To obtain the data in (e) and (f), cells were collected from the bone marrow of Raji tumour cell-bearing mice treated with 1 × 10⁶ CAR T cells on day 28 after cell infusion (n = 4 over two independent experiments). Data for b, d, e and f are presented as the mean ± s.e.m. P values for b, d, e and f were calculated by two-tailed unpaired t test.