The low immunogenicity and immunoregulatory property of MSC-DCs. (A) The influence of MSC-DCs on lymphocyte proliferation. The top panel shows that lymphocytes (H-2K^b) were stained with CFSE and cocultured for 3 days with maDCs (H-2K^d), ConA (5 μg/mL), MSC-DCs (H-2K^d), MSC-DCs (H-2K^d) + Trans, MSC-DCs (H-2K^d) + maDCs (H-2K^d), MSC-DCs (H-2K^d) + ConA (5 μg/mL), MSC-DCs (H-2K^d) + Trans + maDCs (H-2K^d), and MSC-DCs (H-2K^d) + Trans + ConA (5 μg/mL) respectively, then assessed by FACS. Data represent mean (± SD) of triplicate samples. *P < .05. In the bottom panel, 1 FACS analysis of at least 3 independent experiments with similar results is shown. Dotted line, unstimulated lymphocytes. Trans indicates a transwell system used in the MSC-DCs/maDCs/lymphocytes or MSC-DCs/ConA/lymphocytes cocultural system to determine whether intercellular contact or soluble factors were involved in the inhibitory function of MSC-DCs. (B) The influence of MSC-DCs on IFN-γ and IL-2 secretion by lymphocytes. Lymphocytes (H-2K^b) were cocultured for 5 days with maDCs (H-2K^d) or ConA (5 μg/mL) in the absence or presence of MSC-DCs (H-2K^d) or MSC-DCs (H-2K^d) + Trans. IFN-γ and IL-2 in each well were assayed by ELISA. Data are mean (± SD) of triplicate wells. *P < .05.