Immunomodulatory properties of mesenchymal stem cells: cytokines and factors.

Mesenchymal stem cells (MSCs) are defined as undifferentiated cells that are capable of self renewal and differentiation into several cell types such as chondrocyte, adipocyte, osteocyte, myocyte, hepatocyte, and neuron-like cells. MSC can be isolated from bone marrow, umbilical cord blood, adipose tissue, placenta, periosteum, trabecular bone, synovium, skeletal muscle, and deciduous teeth. Immunomodulatory of MSCs is one of the important issues nowadays, because this aspect can be clinically applied for graft-versus-host and autoimmune diseases. In this review, we tried to discuss in detail about cytokines and factors such as members of the transforming growth factor superfamily (transforming growth factor-β), hepatic growth factors (HGF), prostaglandin E2 (PGE2), IL-10, indolamine 2,3-dioxygenase (IDO), nitric oxide (NO), heme oxygenase-1 (HO-1), and human leukocyte antigen-G (HLA-G) that are involved in immunomodulatory of MSCs.