Figure 6

MSCs increase the expression of FoxP3 in naive CD4⁺T cells. (A) Naive CD4⁺T cells co-cultured with MSCs (ratio 1:5)/TGF-β (5 ng/ml) or without MSCs/TGF-β in the presence of anti-CD3/CD28 (2 μg/ml each). T cells were harvested from different treatment groups to assess Foxp3 expression by flow cytometry. (B) MSCs conditioned medium was collected after 48 hours and 72 hours, and then used to stimulate Jurkat cells for different times. were harvested to examine TGF-β signaling by Western blotting of Smad2 and phospho-Smad2. TCR signaling was examined by Western blotting of JNK, phospho-JNK, p38 and phospho-p38. (C) The protein level of p-Smad2 was analyzed using Quantity One. Values are expressed as means ± SEM. *P <0.05 or **P <0.01. MSCs, mesenchymal stem cells; SEM, standard error of the mean; TCR, T cell receptor; TGF-β, transforming growth factor-β.