MSC coculture reduced IL-12 secretion by DCs. (A) DCs obtained from monocytes after 7 days of induction with GM-CSF plus IL-4 were stimulated by LPS for an additional 48 hours with or without MSC coculture, and then cell-free supernatants were collected and quantified by ELISA for IL-12 production. In the meantime, the cell lysates were blotted with anti-p38 antibody (bottom row) and antiphosphor-p38 antibody (top row). (B) Mature DCs with (MSC+) or without (MSC-) MSC coculture were used to stimulate allogeneic CD4⁺ T cells. In the MLR, IL-12, IFN-γ, and IL-10 secretion were quantified by Quantikine ELISA. Thymidine incorporation is expressed as mean ± SD of triplicates. Results are representative of 3 independent experiments (^*P < .05; ^**P < .01).