母胎界面免疫细胞调控滋养细胞生物学行为的确切机制仍不明晰。最近我们发现，CXCR4+/-NK差异表达基因在细胞侵袭迁移功能显著富集。CXCR4+NK显著高表达MMP9促滋养细胞侵袭。EGF通过与CXCR4+NK细胞表面显著高表达EGFR相互作用促MMP9表达。此外，EGFR泛素化E3连接酶在CXCR4+NK显著低表达，推测E3连接酶差异表达调节EGFR泛素化依赖性降解及EGF/EGFR信号介导的MMP9表达调控可能是CXCR4+/-NK差异调节滋养细胞侵袭的分子机制。本研究拟利用正常早孕和自然流产标本，分析相关功能分子在CXCR4+/-NK差异表达；建立CXCR4+/-NK与滋养细胞共培养体系，探究其对滋养细胞生物学行为的差异调节作用。进一步采用过表达、Si-RNA、IP等手段解析CXCR4+/-NK差异调节滋养细胞侵袭的分子机制，为反复自然流产、子痫前期等疾病防治提供新思路。

Immune cells exert critical modulatory effect on the behavior of trophoblast, though the specific mechanism is unclear. Our previous study discovered that CXCR4+NK cells, the unique NK cell subset characterized with high production of IL-4 and the potential to induce Th2 differentiation at the maternal-fetal interface, contribute to the establishment and maintenance of immune tolerance in pregnancy. Recently, further investigation by our team showed that CXCR4+/- NK cells display different gene expression profiles and significant expression genes enrichment involve in the degradation of extracellular matrix, cell migration and invasion. Compared to CXCR4- NK cells, CXCR4+ NK cells had a significant higher expression of mmp9 and promoting effect on trophoblast invasion showed by our preliminary experiment. EGFR was also significantly higher expressed on CXCR4+ NK cells than that on CXCR4- NK cells. Moreover, rhEGF interacted with EGFR led to significant upregulation of mmp9 in NK cells. Coincidently, EGFR degradation associated E3 ubiquitin ligases were significantly lower expressed in CXCR4+ NK cells. Therefore, we speculated that significant lower expression of EGFR E3 ubiquitin ligases in CXCR4+NK cells inhibited the ubiquitination-dependent degradation of EGFR, ensuring the activation of signal pathway of EGF/EGFR and mmp9 production, which was the underlying mechanism of CXCR4+ NK cells facilitating trophoblast invasion. In this project we plan to analyze the functional molecules including mmp9, EGFR on CXCR4+/- NK cells in decidua derived from normal early pregnancy and spontaneous abortions. Explore the effect of CXCR4+/-NK cells on the behavior of throphoblast by the co-culture system. Further study is designed to investigate the specific mechanism of CXCR4+/- NK cells-exerted differential modulation on trophoblast invasion via E3 ubiquitin ligases /EGFR/EGF/MMP9 axis. We attempt to provide new insights for the diagnosis and treatment of pregnancy associated diseases including recurrent spontaneous abortion and preelampsia.