Inhibition of zymosan-induced TNF-α expression in the peritoneum and in cultured macrophages. (A) ELISAs for mTNF-α in lavage fluid. Values are mean ± SD (n = 3; *P < .05). (B) Mouse-specific real-time RT-PCR assays for mTNF-α in macrophages stimulated with zymosan with or without various numbers of hMSCs. Data are expressed as mean and range of 2 values. (C) As in panel B except that the cocultures contained hMSCs (1:10 ratio to macrophages) and the hMSCs were either standard preparations or hMSCs activated to express TSG-6 by incubation with hTNF-α. (D) As in panel C except that the hMSCs were either activated hMSCs transfected with scrambled siRNA (scr) or activated hMSCs transfected with an siRNA for TSG-6. (E) As in panel D except murine macrophages cultured with zymosan with or without TSG-6. Values in panels C, D, and E are mean ± SD (n = 3; *P < .05).