TGFβ1 plays a key role in the MSC-mediated inhibition of DCs differentiation and functions.

Abstract

<p>Monocytes were cultured with GM-CSF and IL-4 to induce differentiation into DCs. Cultures were performed either in the absence or in the presence of MSC. In addition, anti-rhTGF-β1, or anti-rhIL-6, or 1-methyltryptophan, IDO inhibitor, or indomethacin, PGE2 inhibitor, or PBIT, NO inhibitor was added to monocyte-MSC cocultures. After 5 days, expression of CD1a (A) and CD14 (B) in cells cultured under the described was performed to check DCs differentiation. (C) IL-12 was measured in culture supernatants after 48-hour stimulation with LPS of monocyte-derived cells cultured for 7 days with GM-CSF and IL-4 either in the absence or in the presence of MSC., anti-rhTGF-β1, or anti-rhIL-6, or 1-methyltryptophan, IDO inhibitor, or indomethacin, PGE2 inhibitor, or PBIT, NO inhibitor was added at the beginning of the culture. DCs obtained from monocytes after 7 days of induction with GM-CSF plus IL-4 were stimulated by LPS for an additional 48 hours without MSC coculture. (D) anti-rhTGF-β1, or anti-rhIL-6, or 1-methyltryptophan, IDO inhibitor, or indomethacin, PGE2 inhibitor, or PBIT, NO inhibitor was added at the beginning of MLR coculture. T-lymphocyte proliferation was assessed by [3H]-thymidine incorporation. Data are expressed as mean±SD of triplicates of 5 separate experiments. *P≤0.05.</p