骨髓间充质干细胞对植物血球凝集素刺激的T淋巴细胞CD25表达的影响

Mesenchymal stem cells inhibit the expression of CD25 on phytohaemagglutinin-activated lymphocytes

目的利用 T 淋巴细胞激活后早期表达的膜表面分子 CD25和 CD69来观察骨髓间充质干细胞(MSC)对于 T 淋巴细胞增殖的抑制作用。方法体外扩增并鉴定大鼠 MSC,采用尼龙棉柱纯化大鼠 T 淋巴细胞。将 MSC 和 T 淋巴细胞共培养,加入植物血球凝集素(Phytohaemagglutinin,PHA)进行刺激后测定 T 淋巴细胞膜表面 CD25和 CD69的表达。ELISA 法测定 MSC 培养上清液的转化生长因子(TGF)-β1和 IL-10的浓度。结果①10 000个以上的 MSC 和 T 淋巴细胞共培养时,CD25的表达明显下调,而且下调作用具有数量依赖性。100个 MSC 对于 T 淋巴细胞 CD25的表达没有作用;②MSC 对于 T 淋巴细胞 CD25的下调可以持续96 h 以上;③MSC 对于 T 淋巴细胞 CD25的下调介于其自身分泌的可溶性蛋白质;④TGF-β1和 IL-10均不是 MSC 介导 T 淋巴细胞 CD25下调的原因。结论 MSC 具有 PHA 刺激的 T 淋巴细胞免疫调节作用,其在移植免疫方面的应用前景非常光明。

Objective To investigate the regulatory effects of rat mesenchymal stem cell（ MSC ） on T lymphocyte proliferation by examining the early activated markers such as CD25 and CD69. Methods MSC had been isolated and expanded in vitro. Then it was identified by cell morphology, membrane phenotype, and differentiation potential. Nylon wool column was applied to purify T-lymphoeytes. MSCs and T-lymphoeytes were cultured together and were stimulated by phytohaemagglutinin （ PHA ）, and then the expressions of CD25 and CD69 were assessed. The levels of TGF-β1 and IL-10 in the supernatants of MSC cultures were detected by using ELISA. Results ①The expression of CD25 is suppressed in a dose- dependent manner when the T-lymphoeytes are co-cultured with 10,000 MSCs or more, while 100 MSCs have no detectable effect; ②The suppression of CD25 can be lasted more than 96 In＇s; ③The down regulation of CD25 is mediated by some soluble factors; ④The reduced expression of CD25 caused by MSC inhibition is not mediated by TGF-β1 and IL-10. Conclusion MSCs have significant immune regulatory effects on PHA-stimulated T-lymphocyte culture. It might provide a remarkable immune suppression in organ- transplantation to achieve better outcome in the near future.