Fig. 4

hMSCs exert different immunosuppressive function. A Representative flow cytometry histogram shows the proliferation of CFSE-labeled CD4⁺ T cells directly cocultured with hMSCs. hMSCs: PBMC = 1:1 or 1:10. B Representative flow cytometry histogram shows the proliferation of CFSE-labeled CD4⁺ T cells directly or indirectly (TW) cocultured with MSCs. MSCs: PBMC = 1:2. C Flow cytometric quantitation of CD4⁺ T cells proliferation at different ratios (n = 3). D Flow cytometric quantitation of CD4⁺ T cells proliferation with or without transwell as shown in Fig. 4B (n = 3). Bars in C and D represent mean ± SD. N Negative control that PBMC were left untreated; PBMC peripheral blood mononuclear cells; P Positive control that PBMC were stimulated by CD3e/CD28 beads; TW transwell. All PBMC were stimulated by CD3e/CD28 beads at the ratio of 1:1. *P < 0.05; **P < 0.01; ns not significant; P values were calculated by unpaired t-test