A role for mesenchymal stem cells in the control of graft-versus-host disease

Several reports have demonstrated the ability of mesenchymal stem cells (MSCs) to enhance hemopoietic engraftment and to exert a profound inhibitory effect on T-cell proliferation in vitro, making them a candidate for the prevention/treatment of graft-versus-host disease. Recent publications have highlighted the underlying mechanisms of the immunosuppressive function of MSCs, elicited by proinflammatory cytokines, such as interferon-gamma and tumor necrosis factor-alpha. These new findings have lead to a better understanding of the biology of MSCs, the outcome of graft-versus-host disease clinical trials and the conflicting results of preclinical T-cell-dependent pathologies. The potential use of MSCs as immunosuppressive elements in allogeneic stem-cell transplantation settings is thus discussed below.