Fig. 2

The BB-ζ-C3aR CAR-T cells significantly eradicated BCMA-expressing tumor cells through favoring Th17 cells expansion and memory T cells induction. a IM9-Luc cells with 5 × 10⁵ dose were administered intravenously into NCG mice to establish the MM model. These mice were randomized to the treatment of 2 × 10⁶ indicated T cell on Day 8 and Day 12. IM9 tumor growth was then monitored by Xenogen imaging. b Bioluminescence images of MM mice on Days 7, 14, 21, 28, and 35 are depicted for each group. c The curve of flux on indicated time points. d Kaplan–Meier survival analysis showed the longest time of survival in BCMA-BB-ζ-C3aR CAR-T cells group. e Hardly any BCMA⁺ tumor cells were detected in peripheral blood from mice treated with BCMA-BB-ζ-C3aR CAR-T cells. f In the xenograft MM mice, the BCMA-BB-ζ-C3aR CAR-T cells promoted the generation of IL-17-expressing Th17 cells and reduced the Tregs compared to the BCMA-BB-ζ CAR-T cells group. g A fraction of CD4⁺ or CD8⁺ cells exhibited the features of central memory cells (Tcm) with notably high expression of CCR7 and CD45RO. Tcm cells in CD8⁺ compartment were increased in the BCMA-BB-ζ-C3aR CAR-T-treated mice compared to BCMA-BB-ζ controls. In addition, the percentage of CD45RO⁺CCR7⁻ effector memory cells (Tem) was significantly increased in both CD4⁺ and CD8⁺ compartments in the BCMA-BB-ζ-C3aR CAR-T cells. ***p ≤ 0.001; **p ≤ 0.01; *p ≤ 0.05, n.s. no significant