Immunoregulation by Mesenchymal Stem Cells: Biological Aspects and Clinical Applications

Figure 2

Immunoregulatory effects of MSCs on immune cells. Proinflammatory cytokines such as IFN secreted by activated NK cells and T lymphocytes support MSCs-mediated immunoregulation and can increase or induce the production of immunosuppressive molecules. IDO, PGE₂, , and membrane molecules are mainly involved in MSCs immunoregulation on NK cells. IDO, PGE₂, and IL-10 are involved in the decrease of differentiation of monocytes into iDCs and may push mDCs toward an immature state, which results in T-cell anergy and inappropriate activation of T lymphocytes. MSCs induce the differentiation of CD34⁺ hematopoietic progenitors into a population of regulatory DCs, which in turn stimulate the generation of Foxp3⁺ Tregs.