Fig. 4: Adoptive transfer of mast cells promoted disease severity and T cell response in CIA mice.

a The schematic diagram of study design: After subcutaneous immunization of CII and CFA at the tail on day 0, 5×10⁶ mast cells were adoptively transferred through tail vein injection on day 7 and day 14. b Clinical scores of control group and transfer group (n = 6 mice for each group, pooled from two independent experiments, P = 0.0016). c Representative immunofluorescence images of synovial tissues from control group and transfer group. Red, tryptase; Green, CD3; Blue, DAPI. Scale bar: 50 μm. White dotted lines represent the boundary between lining layer and sub-lining layer. The area in the white box is enlarged as an inset. Data are representative of 6 biologically independent samples. d Frequencies of CD4⁺IFN-γ⁺ cells, CD4⁺IL-17A⁺ cells, and CD4⁺Foxp3⁺ cells in the spleen detected by flow cytometry (n = 10 mice for PBS, n = 9 mice for BMMC, pooled from two independent experiments, P = 0.0175). e Frequencies of CD4⁺IFN-γ⁺ cells, CD4⁺IL-17A⁺ cells, and CD4⁺Foxp3⁺ cells in the draining lymph nodes detected by flow cytometry (n = 10 mice for PBS, n = 9 mice for BMMC, pooled from two independent experiments, *P = 0.0183, **P = 0.0026). f Serum levels of anti-CII IgG, IgG1, and IgG2a were quantified by ELISA (n = 10 mice for PBS, n = 9 mice for BMMC, pooled from two independent experiments, **P = 0.0012, *P = 0.0112). g Representative flow plots of CFSE-labeled splenocytes gated on CD3⁺CD4⁺ cells after being stimulated with CII for 4 days. h Statistical analysis of proliferation rate after CII stimulation (n = 10 mice for PBS, n = 9 mice for BMMC, pooled from two independent experiments, P < 0.001). i) Inflammatory cytokines released from splenocytes (n = 10 mice for PBS, n = 9 mice for BMMC, pooled from two independent experiments, P < 0.001). Data are presented as the mean ± SEM and analyzed using two-way ANOVA (b, d, e), two tailed unpaired t test (f, h, i). *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001. Source data are provided as a Source Data file.