Mesenchymal stem cells and immune modulation

Abstract

Objective: Mesenchymal stem cells (MSCs) have the capacity of escaping the immune recognition and inhibiting the immune response. This article was designed to review these phenomena. Data Sources: With the key words of "mesenchymal stem cells,immune modulation", Pubmed database was undertaken to identify the relevant articles published from January 1976 to January 2006 in English. Study Selection: After the data were researched firstly, every citation was checked in each article. Inclusive criterion included articles on MSCs and their immune modulation. Exclusive criteria included repetitive studies or Meta analysis articles. Data Extraction: Totally 263 related papers were selected and 68 papers were accorded with the inclusive criterion. The excluded 195 papers were old or repeating. The 68 articles were concerned about immunogenicity of MSCs, immune inhibiting effect and mechanism and application of MSCs. Data Synthesis: MSCs widely exist in all kinds of tissues. They are able to escape the alloantigen recognition because of their low immunogenicity. MSCs can inhibit immune response both in vivo and in vitro. The inhibiting effect is related with the modulation of dendritic cells, T cells and nature killer cells. MSCs can still affect some soluble factors, such as transforming growth factor, interleukin, stroma cell factors, NF-κB ligand, prostaglandin and 2, 3-indolakylamine oxidase. MSCs have well application perspective because of their immune modulation ability. Presently, they have been used in the treatment of graft versus host disease and autoimmune disease. Conclusion: MSCs have been shown to suppress activation of T cells both in vivo and in vitro. MSCs modulate the immune function of the major cell populations involved in alloantigen recognition and elimination, including antigen presenting cells, T cells, and natural killer cells. The molecular mechanism that mediates the immunosuppressive effect of MSCs is not completely understood.