人早孕期蜕膜基质细胞下调蜕膜NK细胞杀伤活性

通过分析人早孕期蜕膜基质细胞(decidual stromal cell,DSC)对蜕膜NK细胞(dNK)表面趋化因子受体CXCR4与细胞内颗粒酶B表达水平的影响,研究早孕蜕膜基质细胞对局部NK细胞的训导作用。收集早孕蜕膜组织,分离DSC及蜕膜免疫活性细胞,进一步通过磁珠分选蜕膜CD3-CD56bright NK细胞,将分离的蜕膜NK细胞与DSC按1∶1比例共培养24h,收集蜕膜NK细胞,流式细胞仪检测其表面趋化因子受体CXCR4和细胞内颗粒酶B(granzyme B)的表达水平。结果显示,与对照组相比,在与DSC细胞共培养之后,趋化因子受体CXCR4+NK细胞的百分率明显上升,而蜕膜NK细胞内颗粒酶B阳性率显著下降(P<0.05)。结果表明,人早孕母-胎界面DSC细胞上调蜕膜NK细胞表面趋化因子受体CXCR4的表达,下调NK细胞内颗粒酶B的表达水平,可能抑制其杀伤活性。

The decidual stromal cells can down-regulate the cytotoxity of decidual NK cells during human first trimester pregnancy

To investigate the regulation by the first trimester decidual stromal cells(DSC) on decidual NK cells(dNK),we analyzed the expression of CXCR4 and the production of Granzyme B in decidual CD3-CD56+ NK cells after being cocultured with DSC.Human decidual tissues were collected in artificial abortion during 6～10 weeks of gestation and digested with collagenase Ⅳ.After density gradient centrifugation,DSC and decidual immno-components cells(DICs) were obtained respectively.Decidual NK cells were further purified by CD3 and CD56 MACS.The purity of DSC and dNK was characterized by immunocytochemistry and FCM,respectively.The purified dNK were cultured in the absence or presentce of DSCs for 24 h and then harvested to detect the expression of CXCR4 and Granzyme B.It was found that the purity of isolated DSCs was almost 100% and there were above 95% CD3-CD56+ cells in this purified NK cells.The percentage of CXCR4+ dNK was significantly increased after co-cultured with DSC.However,the production of Granzyme B in dNK was decreased in the presence of DSC.These results suggest that DSC can regulate phenotype and function of decidual NK cells,and DSC may inhibit cytotoxity of dNK cells through increasing CXCR4 expression.