骨髓间质干细胞吲哚胺2，3-双加氧酶活性对T淋巴细胞的影响(英文)

目的: 探讨骨髓间质干细胞（MSCs）吲哚胺2，3-双加氧酶（IDO）活性对抑制T淋巴细胞应答反应的影响。方法: 从人骨髓中分离培养间质干细胞,通过其形态特点、表面标志及多向分化能力检测进行鉴定。以浓度为2×105 U/L的 IFN-γ对分离的MSCs诱导18 h，检测MSCs上IDO mRNA和IDO蛋白表达。将经过IFN-γ 2×105 U/L诱导的MSCs预先接种在培养板中，再建立混合淋巴细胞培养(MLR)体系，利用MTT法检测T淋巴细胞增殖率，并用反相高效液相色谱法检测IDO活性。结果: IFN-γ能诱导MSCs上IDO mRNA和IDO蛋白的表达；MSCs的IDO活性抑制MLR体系中T淋巴细胞增殖率。结论： 经IFN-γ刺激后的MSCs在体外可抑制异体T淋巴细胞的免疫应答，IDO活性参与了这种免疫抑制作用的发挥。

Mesenchymal stem cells suppress T-lymphocyte responses by indoleamine 2,3-dioxygenase activity

AIM: To investigate the influence of mesenchymal stem cells (MSCs) expressing indoleamine 2, 3-dioxygenase (IDO) activity on the allogeneic T-lymphocyte responses.METHODS: MSCs were isolated and cultured from human bone marrow. Selected surface markers of MSCs were detected by flow cytometry and their morphologic characteristics were determined by microscopy. The pluripotentiality of MSCs was also studied. IDO mRNA and IDO protein expressions in MSCs induced by γ-interferon (IFN-γ) at the concentration of 2×105 U/L were detected. MSCs induced by IFN-γ at the concentration of 2×105 U/L were plated in dishes and then mixed lymphocyte reaction (MLR) cultures were set up. T-lymphocytes proliferation was determined by MTT assays and IDO activity was measured by high-performance liquid chromatography (HPLC). RESULTS: IFN-γ could stimulate IDO mRNA and IDO protein expressions in MSCs. IDO enzyme activity in induced MSCs inhibited T-lymphocyte proliferation of MLR cultures. CONCLUSION: MSCs could suppress T-lymphocyte responses via IDO enzyme activity in vitro.