Immunomodulation by multipotent mesenchymal stromal cells.

Multipotent mesenchymal stromal cells (MSC) are currently under intense investigation to determine their role in cellular therapy. They are a rare subset of cells, but are easy to isolate and possess an extensive proliferative potential. MSC differentiate into cell types of mesenchymal and nonmesenchymal lineages, providing a promising tool for tissue repair. Studies in vitro have shown that they do not induce an immune response and inhibit cells of the immune system that are involved in alloantigen recognition and elimination. In animal models, MSC appear to have anti-inflammatory effects, which has also been observed in patients suffering from acute graft-versus-host disease. The unique properties of MSC suggest emerging roles for them in cell therapy and in the treatment of immunomediated diseases.