The immune properties of mesenchymal stem cells.

The goal of this review is to summarize current knowledge on the immune properties of mesenchymal stem cells (MSCs) and to discuss how these properties might affect clinical applications, in particular tissue regeneration. Mesenchymal Stem Cells (MSCs) are pluripotent cells with unique immune properties. They show immunoenhancing as well as immunosuppressive properties. It is the latter property that makes them stem cells of interest by scientists since they could be ideal for tissue regeneration, across allogeneic barrier. MSCs can transdifferentiate and differentiate into specialized cells. Although found mostly in the adult bone marrow, MSCs also reside in a variety of fetal tissues. In the adult bone marrow they act as "gatekeeper" cells regulating traffic in and out to the peripheral circulation and lymphatics. Their location within the vicinity of the bone marrow and periphery allows the MSCs, through their immune suppressor ability and antigen presenting property (APC) to maintain homeostasis in bone marrow function. There is potential for clinical therapy with MSCs. They have the potential to facilitate bone marrow transplantation by reducing graft-versus-host disease (GVHD). In addition, their immunosuppressive properties show promise for cell therapy across allogeneic barrier. Their role in the bone marrow, as it relates to hematological disorder is discussed.