Fig. 3: CD24-CAR-T cells target MM cells and promote macrophage phagocytic clearance in vivo.

a Schematic approach for 5TGM1 mouse model. C57BL/KaLwRij mice were intravenously injected with either PBS or 5TGM1-GFP-DiD cells. After 7 days after injection of 5TGM1 cells, mice were treated with either PBS, MOCK-CAR-T cells, or CD24-CAR-T cells. On day 21 after 5TGM1-cell inoculation, mice were killed. Serum electrophoresis (SPE) was performed. Bone marrow mononuclear cells (BMMCs) were isolated. Dormant (GFP⁺DiD^Hi) and activated (GFP⁺DiD^Neg) cells were detected by flow cytometry. BM microenvironmental cells were sorted out for single-cell RNA sequencing (scRNA-seq) (n = 5 mice per group). b SPE of 5TGM1 models. The M-spike is indicated in red (n = 5 per group). The gel has been cut from the outside; no samples/bands were removed. The experiment was repeated twice with the same results. c Representative GFP⁺ gating strategy to identify MM cell populations in 5TGM1 BM samples. Bar plot showing the percentage of MM cells (GFP⁺ cells) in 5TGM1 BM samples (n = 3 per group). d Representative F4/80⁺CD11b⁺ gating strategy to identify the population of MM cells phagocytosed by macrophages. Bar plot showing the percentage of GFP⁺ cells phagocytosed by macrophages (n = 3 per group). e Representative CD206⁺ and CD86⁺ gating strategy to identify M2-like-phenotype and M1-like-phenotype cell populations in 5TGM1 BM samples (n = 3 per group). f Bar plot showing the percentage of M1-like-phenotype and M2-like-phenotype macrophages after treatment (n = 3 per group). g Kaplan-Meier survival analysis of CAR-T treatment in 5TGM1 models (n = 5 per group). Data are presented as mean values ± SD in (c, d) and (f). One-way ANOVA was used for statistical analysis. ^∗P < 0.05, ^∗∗P < 0.01, ^∗∗∗P < 0.001, ns = P > 0.05. Raw data are provided in the Source Data file. Exact P values for each comparison shown in (c–f), (g), and (i) can be found in Supplementary Data 1.