Immunomodulatory effect of mesenchymal stem cells
Mesenchymal stem cells represent an adult population of nonhematopoietic cells, which can differentiate into a variety of cell types such as osteocytes, chondrocytes, adipocytes, and myocytes. They display immunomodulatory properties that have led to the consideration of their use for the inhibition of immune responses. In this context, mesenchymal stem cells efficiently inhibit maturation, cytokine production, and the T cell stimulatory capacity of dendritic cells. They also can impair proliferation, cytokine secretion, and cytotoxic potential of T lymphocytes. Moreover, mesenchymal stem cells are able to inhibit the differentiation of B cells to plasma cells by inhibiting their capacity to produce antibodies. A variety of animal models confirm the immunomodulatory properties of mesenchymal stem cells. Clinical studies including patients with severe acute graft-versus-host disease have revealed that the administration of mesenchymal stem cells results in significant clinical responses. Therefore, mesenchymal stem cells improve acute graft-versus-host disease and represent a promising candidate for the prevention and treatment of immune-mediated diseases, due to their immunomodulatory capability and their low immunogenicity.