骨髓间充质干细胞对异体淋巴细胞增殖的负调控作用及其机制的探讨

目的：研究成人骨髓间充质干细胞（mesenehymalstemeeHs，MSCs）的免疫调节作用及其作用机制。方法：从成人骨髓中分离、培养问充质干细胞，并通过其形态的均一性及流式细胞术检测其表面标志以鉴定其纯度。将分离培养的间充质干细胞培养上清置于96孔板中，与经分离的异体淋巴细胞共培养3d，以单独培养的异体淋巴细胞为对照组，加入植物凝血素（PHA）刺激72h，用MTT还原法测定细胞增殖，观察成人骨髓MSCs培养上清对异体淋巴细胞增殖转化的影响。结果：成人骨髓MSCs培养上清抑制异体淋巴细胞增殖转化。两者差异有显著性（P〈0．05），其增殖转化抑制率为9．00％。在有PHA刺激淋巴细胞增殖的情况下，细胞增殖活性进一步下降，两者差异显著（P〈0．01），其增殖转化抑制率达20．91％。结论：成人骨髓MSCs抑制异体淋巴细胞增殖转化，其作用机制部分为非细胞接触作用所致。推测可能是MSCs通过分泌某些可溶性细胞因子而发生作用。

Negative immunomodulatory effects of culture supernatant of bone marrow-derived mesenchymal stem cells on allogeneic lymphocytes proliferation

Objective:To study the immunomodulatory functions of adult human bone marrow-derived mesenchymal stem cells(MSCs) in vitro and explore its mechanisms.Methods:Adult human MSCs were separated with Percoll(1.073 g/ml) and cultured in LG-DMEM containing 10% fetal calf serum.The purity of MSCs was identified with the spindle-fibroblastic morphology by microphotograph and the phenotypes were tested by fluorescence-(activated) cell sorter(FACS).MSCs culture supernatant was plated in 96-well plates and cocultured for 72 h with lymphocytes isolated from allogeneic peripheral blood.Effects of MSCs culture supernatant on lymphocytes and PHAinduced lymphocytes transformation were investigated.The proliferation of lymphocytes was measured by MTT method.Results:Peripheral blood lymphocytes proliferation was suppressed and the inhibition ratio was(9.00%)(P<0.05).When lymphocytes were stimulated by PHA,the suppression effects were even stronger and the inhibition ratio was 20.91%(P<0.01).Conclusion:Adult human bone marrow-derived mesenchymal stem cells can suppress peripheral blood lymphocytes proliferation and the mechanisms may be at least in part due to none-cell-contact.This suppression could be mediated by some soluble suppressive cytokines.