Fig. 1: Precursor exhausted T cells within the tumor-infiltrating CAR-T cells.

a NSG mice subcutaneously inoculated with the A375-mesothelin were treated using mesothelin-targeting CAR-T cells. Intratumoral CAR-T cells were assessed for phenotypic and functional properties at various time points. b Representative flow cytometry plots analyzing PD1 and CCR7 expression. c The frequency of PD1⁺CCR7⁺ cells in the intratumoral CD8⁺ CAR-T cells at early (day 14 or 21) or late (day 26 or 34) time points (n = 6 mice for each group, unpaired two-tailed t-test). Horizontal lines indicate mean values. d Intratumoral CAR-T cells isolated on day 21 or 34 were stimulated in vitro by K562-mesothelin following CFSE labeling. Representative plots analyzing CFSE dilution 6 days after restimulation. e, f Mean fluorescence intensity of CFSE (e) and the frequency of CFSE-diluted dividing cells (f) were plotted against the frequency of CCR7⁺ cells within the CAR-T cell population at the time of T-cell extraction (n = 3–4 cultures for each of the 4 different sample, P-values and coefficients were calculated by Pearson correlation analysis).