Mesenchymal Stem Cells Inhibit the Differentiation of Dendritic Cells Through an Interleukin-6-Dependent Mechanism

Mesenchymal stem cells (MSC) are of particular interest for their potential clinical use in tissue engineering as well as for their capacity to reduce the incidence and severity of graft-versus-host disease in allogeneic transplantation. We have previously shown that MSC-mediated immune suppression acts via the secretion of soluble factor(s) induced upon stimulation. The aim of this study was to identify the molecule(s) involved and the underlying mechanism(s). We show that murine MSC secrete high levels of interleukin (IL)-6 and vascular endothelial growth factor, which are directly correlated to the inhibition of T-cell proliferation. The T-cell activation is partially restored upon addition of a…