Figure 3.

CD45RA⁺ chimeric antigen receptor (CAR)-T cells achieved prolonged tumor control with long-term expansion of CAR-T cells in vivo. We infused 5 × 10⁵ REH-FFLuc cells into NSG mice via the tail vein. Six days later, 1 × 10⁵ RA⁺ CAR-T, RA⁻ CAR-T, or control (EPHB4) CAR-T positive cells were infused into the tail vein of each mouse. (A) Bioluminescence images of groups of five NSG mice after intravenous CAR-T cell infusion. (B) The tumor volumes of each mouse measured as total flux (p/s) are shown. The CD45RA⁺ CAR-T group showed a statistically significant tumor reduction, measured as the mean total flux at day 28, compared with the CD45RA⁻ CAR-T group. (C) The Kaplan–Meier plot of overall survival (each group, n = 5). The CD45RA⁺ CAR-T group achieved prolonged tumor control compared with the CD45RA⁻ CAR-T group. Log-rank test: *P < 0.05. (D) On day 15 after CAR-T cell injection, bone marrow analysis showed CAR-T cells (left), REH cells (middle), and PD-1 expression on CAR-T cells (right) by flow cytometry. (E) In most long-lived mice infused with RA⁺ CAR-T cells, CAR-T cells, and REH cells in the bone marrow of mice on days 15, 25, and 50. Representative dot plot data are shown. All data are presented as mean ± standard deviation. *P < 0.05.