利用人类胎盘滋养层干细胞研究寨卡病毒的胎盘嗜性

寨卡病毒可突破胎盘屏障导致新生儿小头畸形的发生，严重威胁人类的健康。已有研究表明，寨卡病毒可有效感染人类胎盘中的细胞滋养层细胞及巨噬细胞，但由于缺乏合适的体外研究模型，其内在感染机制尚未完全阐明。至此，我们基于原代分离的可修饰并且可体外分化模拟人类胎盘全谱系滋养层细胞类型的人类胎盘滋养层干细胞系TS开展研究。前期研究发现寨卡病毒能够在TS及其分化的合体滋养层（STB）和绒毛外滋养层细胞（EVT）中建立感染，同时鉴定了AXL等已知病毒受体也在TS中表达。本项目拟利用病原学、免疫学等技术手段鉴定寨卡病毒在不同滋养层细胞中的感染特征，评价感染对细胞增殖、分化的影响；接着结合多组学挖掘潜在的宿主调控因子；最后利用基因编辑技术进行验证。通过上述研究，我们提供了一种先进的研究寨卡病毒侵染人类胎盘的平台，以全新的角度揭示寨卡病毒入侵母胎界面的机制，最终为阻断寨卡病毒垂直传播提供理论支撑。

Zika virus(ZIKV) has the capacity to cross the placental barrier and lead to microcephaly, presenting a tough challenge to public health. Thus far, what has experimentally learned about ZIKV infection of the human placenta comes from some studies in isolated primary placental cells, demonstrating the susceptibility of placental macrophages（Hofbauer cells）and cytotrophoblasts (CTBs) to ZIKV. While it has still remained unknown the mechanism of ZIKV placental tropism due to lack of proper in vitro cell models. Here we provide a kind of human trophoblast stem cells(TS) derived from blastocyst. The TS can be modified and have the capacity to give rise to the major trophoblast lineages, which show transcriptomes similar to those of the corresponding primary trophoblast cells. Here we use TS to study placental tropism of ZIKV. Apart from TS, our previous study has shown that other major trophoblast subpopulations(STB、EVT) differentiated from TS could be infected by ZIKV. In addition, some flavivirus attachment factors like AXL is also expressed in TS. And these finds will contribute to study on mechanism of placental tropism of ZIKV. Based on the established TS vitro cell models, here we will firstly investigate infectious features of ZIKV in different trophoblasts, and whether ZIKV infection would affect TS proliferation and differentiation. Then we will explore the critical regulatory host factors during ZIKV infection with multi-omics and CRISPR/Cas9. Above all, this project will offer a powerful platform for study ZIKV at feto-maternal interface. And it also reveal the mechanism of ZIKV placental tropism in a new way, which may contribute to block ZIKV vertical transmission.