骨髓间充质干细胞抑制T淋巴细胞增殖和miRNA-155表达的体外研究

Bone Mesenchymal Stem Cells can Inhibit Cell Proliferation and miRNA-155 Expression of T Lymphocytes in vitro

目的探讨骨髓间充质干细胞(MSCs)对单向混合淋巴细胞反应(MLR)培养体系中被激活的T淋巴细胞增殖和miRNA-155表达的影响。方法体外培养SD大鼠MSCs,采用流式细胞仪检测MSCs细胞表面标记CD11b/c、CD34、CD44和CD90;分别通过成骨和成脂诱导鉴定MSCs的分化潜能。免疫磁珠分选SD大鼠脾T淋巴细胞,并行纯度及活性检测。以SD大鼠T淋巴细胞作为反应细胞、丝裂霉素C灭活的Wistar大鼠单个核细胞作为刺激细胞建立单向MLR培养体系。CCK-8法检测MSCs对MLR中被激活的T淋巴细胞增殖的影响。Rea1-time PCR法检测MSCs对MLR中被激活的T淋巴细胞miRNA-155表达的影响。结果流式细胞仪鉴定结果显示:CD44及CD90的阳性细胞数分别为(98.9%±0.8%)、(98.1%±0.9%),而CD11b/c及CD34的阴性细胞数分别为(85.1%±0.6%)、(98.0%±0.8%)。培养的MSCs具有成骨和成脂分化潜能。所分选的T淋巴细胞纯度为(91.9%±1.2%)。MSCs可明显抑制单向MLR培养体系中激活的T淋巴细胞的增殖和miRNA-155表达,且这种抑制作用呈明显的浓度依赖性。结论 MSCs能够降低被激活的T淋巴细胞中miRNA-155的表达,这可能在MSCs调节T淋巴细胞增殖和免疫功能的过程中发挥了重要作用。

Objective To explore the effect of bone mesenchymal stem cells （MSCs） on cell pro-liferation and miRNA-155 expression of activated T lymphocytes in the one-way mixed lymphocyte reaction （MLR） system . Methods MSCs were isolated from SD rats and cultured in vitro . Cells were identified with a flow cytometer for the expression of CD11b/c ,CD34 ,CD44 and CD90 . The differentiation ability of MSCs was identified by osteogenic and adipogenic induction . The one-way MLR system was estab-lished with T lymphocytes isolated from the spleens of SD rats by immunomagnetic beads and inactivated mononuclear cells solated from the spleens of Wistar rats . The effect of MSCs on cell proliferation and miRNA-155 expression of activated T lymphocytes in the one-way MLR system were respectively detected by CCK-8 assay and rea1-time PCR . Results Cultured MSCs were negative for CD11b/c and CD34 [（85 .1% ± 0 .6% ） and （98 .0% ± 0 .8% ） , respectively ] but positive for CD44 and CD90 [（98 .9%± 0 .8% ） and （98 .1% ± 0 .9% ） ,respectively] . The cells had the ability of osteogenic and adipogenic dif-ferentiation . The proliferation and miRNA-155 expression of activated T lymphocytes in the one-way MLR could be significantly inhibited by MSCs in a dose-dependent manner . Conclusions The expression of miRNA-155 in activated T lymphocytes can be down-regulated by MSCs ,which may play an important role in the regulaton of MSCs on cell proliferation and immune function of T lymphocytes .