Therapeutic application of mesenchymal stromal cells in autoimmune disease

Mesenchymal stromal cells (MSC) are characterized by their proliferative capacity, their phenotype and their ability to multipotent differentiation. However, little is known about their function and characteristics in vivo. MSC posses a tropism for injured tissues. Numerous investigations of MSC in different model systems suggest an immunosuppressive potential, although the results are in part contradictory. Apparently, MSC exert these effects on nearly all cells in the immune system. However, the relevance and mechanisms of these phenomena in vivo are not clear. The clinical effectiveness of allogeneic MSC in the treatment of refractory graft-versus-host disease has raised hopes that MSC could offer a new concept for the therapy of other immune-mediated disorders. However, before MSC are introduced in clinical practise, several important questions as to their side effects have to be addressed. This includes the possibility that MSC may contribute to the induction of malignant diseases.