Ming Li and Susumu Ikehara
Mesenchymal stem cells (MSCs) are prototypical adult stem cells, identified as an adherent, fibroblast-like population positive for CD105, CD90 and CD73, and lacking hematopietic markers. MSCs can be isolated from different adult tissues including bone marrow (BM), umbilical cord, skeletal muscle and adipose tissue. MSCs have a potent immunomodulatory function via soluble factors, including PGE2, TGF-β, indoleamine 2,3-dioxygenase (IDO), IL-10, and HGF. Treatment with MSCs can improve type 1 diabetes, liver fibrosis and arthritis via their immunomodulatory function. Intra-bone marrow bone marrow transplantation (IBM-BMT) can replace not only hemopoietic stem cells (HSCs) but also MSCs. IBM-BMT seems to be the best strategy for allogeneic BMT, and may improve aging-related diseases, including type 2 diabetes and osteoporosis. IBM-BMT has also been shown to be the most effective strategy to prevent the rejection of organ allografts. This review summarizes the immunomodulatory properties and therapeutic application of bone marrow derived-MSCs.