Study Of Immunological Characteristics Of Amnion-derived Mesenchymal Stem Cells

【Objective】To isolate and culture mesenchymal stem cells from amnion,analyze their immunological characteristics and the effect on lymphocytes transformation with a view to looking for a new source from which it was more accessible to acquire,easier to culture and purify mesenchymal stem cells.To provide experimental evidence for improving the successful rate of clinical hematopoietic stem cell transplantation and reducing graft-versus-host disease.【Methods】Mesenchymal stem cells were isolated and cultured from amnion by the tissue pieces culture method.The expression of HLA-A,B,C,HLA-DR,and costimulatory molecules such as CD80,CD86,CD40 which were necessary for T lymphocytes activation of amnion-derived mesenchymal stem cells was analyzed by flow cytometry.The ability of stimulating allogeneic T lymphocytes proliferation of amnion-derived mesenchymal stem cells was detected by mixed lymphocytes reaction.The circumstances of influencing adult peripheral blood lymphocytes transformation of amnion-derived mesenchymal stem cells were observed by CCK-8.【Results】Amnion-derived mesenchymal stem cells had low immunogenicities. The surfaces of them expressed low level of HLA-A,B,C,did not express HLA-DR and CD80,CD86,CD40.They did not cause the proliferation of allogeneic T lymphocytes.They inhibitted the transformation of adult peripheral blood lymphocytes,and this inhibition had a dose-dependent manner.When the ratios of amnion-derived mesenchymal stem cells and lymphocytes were 1:10 and 1:50, amnion-derived mesenchymal stem cells were unable to stimulate allogeneic T lymphocytes proliferation.When the ratio of amnion-derived mesenchymal stem cells and lymphocytes was 1:1,the average inhibition rate of lymphocytes transformation was 88.92%.When the ratio of amnion-derived mesenchymal stem cells and lymphocytes was 1:2,the average inhibition rate of lymphocytes transformation was 83.38%.When the ratio of amnion-derived mesenchymal stem cells and lymphocytes was 1:4,the average inhibition rate of lymphocytes transformation was 62.10%.When the ratio of amnion-derived mesenchymal stem cells and lymphocytes was 1:8,the average inhibition rate of lymphocytes transformation was 32.22%.When the ratio of amnion-derived mesenchymal stem cells and lymphocytes was 1:16,the average inhibition rate of lymphocytes transformation was 17.35%.【Conclusion】Mesenchymal stem cells can be successfully isolated and cultured from amnion.They will play an important role in inducing immune tolerance, reducing and preventing GVHD through the use of their low immunogenicities and immune modulatory effect on lymphocytes.They may enhance the successful rate of HSCT and reduce the incidence of GVHD.