Spatiotemporal transcriptomics at the maternal-fetal interface in COVID placenta

由严重急性呼吸综合征冠状病毒2(sars-cov-2)引起的新冠肺炎已成为 这是对全球健康的最大威胁，并对全世界的孕妇产生重大影响。新冠肺炎在中国的感染 怀孕与产妇发病率和死亡率以及新生儿增加的风险很大相关。 与未感染的孕妇相比，并发症的发生率更高。然而，垂直传播的 病毒并不常见，这表明先天免疫系统必须在母婴界面发挥作用 保护发育中的胎儿免受感染。尽管对SARS的许多方面进行了快速密集的研究- CoV-2、病毒感染对胎盘的影响和胎盘防御机制较差(S) 探索过了。胎盘是病原体传播的结构和免疫屏障。去探索先天的 抗病毒防御机制(S)，在我们的初步研究中，我们特异性地确定了干扰素的表达 胎盘组织中的通路相关分子。引人注目的是，我们发现了干扰素刺激物的不同模式 基因(STING)、干扰素调节因子3(IRF3)和I型干扰素(如IFNb)在母体- 新冠肺炎感染者胎盘的胎盘界面。刺痛是病毒感染的传感器。 STING-IRF3信号通路调节I型干扰素的产生，I型干扰素是一种有效的抗病毒细胞因子。 我们还注意到Toll样受体7(TLR7)在合体滋养层细胞( STS)和 新冠肺炎患者与非新冠肺炎患者胎盘绒毛外滋养细胞(EVT)的比较。TLR7， 位于X染色体上，是单链RNA(SsRNA)病毒的传感器。这些发现很耐人寻味 并表明先天性抗病毒免疫系统在母婴交界处被激活 怀孕期间吃新冠肺炎。这项研究的目的是识别时空转录特征。 母胎交界处的先天抗病毒免疫系统网络。我们将检验这一假设 有效和强大的先天抗病毒免疫系统在母胎界面被激活，以防止 病毒传播和保护胎儿免受感染，这将在两个特定的目标进行测试。 目标1将 确定绒毛组织中响应母体免疫的时空天然免疫基因图谱和网络 SARS-CoV-2感染。目标2将鉴定胎儿的时空天然免疫基因图谱和网络 对母体SARS-CoV-2感染有反应的膜和蜕膜组织。一部最先进的小说 福尔马林固定的胎盘石蜡包埋10倍基因组病毒基因表达检测技术 (FFPE)组织将与RNA-SEQ相结合 。活动性冠状病毒感染妇女的胎盘， 将研究从COVID感染中康复，以及接受COVID疫苗接种等。这部小说的理想 方法将使我们能够绘制整个转录组与胎盘FFPE组织中的形态背景和 了解不同细胞类型和基因活性中的细胞和分子图谱和网络 在不破坏组织完整性的情况下，母胎界面。这项研究的结果将提供新的见解 关于如何 SARS-CoV-2感染 影响母胎界面的先天免疫系统，以及 母胎交界处的先天性免疫系统对怀孕期间接种柯萨奇病毒疫苗做出反应，这是 可能有助于确定预防新冠肺炎感染和减少母婴并发症的新策略 在未来感染新冠肺炎的女性中。

COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has emerged as the greatest threat to global health and significantly impact pregnant women worldwide. COVID-19 infection during pregnancy is associated with substantial risk of increases in maternal morbidity and mortality and neonatal complications, compared with their non-infected pregnant counterparts. However, vertical transmission of the virus is uncommon, which suggest that innate immune system must function at the maternal-fetal interface to shield the developing fetus from infection. Despite fast-tracked intensive research on many aspects of SARS- CoV-2, the impact of the viral infection in the placenta and the placental defense mechanism(s) are poorly explored. Placenta is the structural and immunological barrier of pathogen transmission. To explore the innate antiviral defense mechanism(s), in our preliminary study we specifically determined expression of interferon pathway-related molecules in placental tissues. Strikingly, we found distinct patterns of stimulator of interferon genes (STING), interferon regulator factor 3 (IRF3), and Type I IFN (such as IFNb) expression at the maternal- fetal interface of the placentas from women infected with COVID-19. STING is a sensor for viral infection. STING-IRF3 pathway signaling regulates Type I IFN production, and Type I IFNs are potent antiviral cytokines. We also noticed that Toll-like receptor 7 (TLR7) is upregulated in both syncytiotrophoblasts ( STs) and extravillous trophoblasts (EVTs) in placentas from patients with COVID-19 compared to those are not. TLR7, located on the X chromosome, is a sensor for single strand RNA (ssRNA) viruses. These findings are intriguing and indicate that an innate antiviral immune system is activated at the maternal-fetal interface in patients with COVID-19 during pregnancy. The objective of the study is to identify spatiotemporal transcriptomic signatures and networks of the innate antiviral immune system at the maternal-fetal interface. We will test the hypothesis an effective and robust innate antiviral immune system is activated at the maternal-fetal interface to prevent viral transmission and shield the fetus from infection, which will be tested in two specific aims. Aim 1 will identify spatiotemporal innate immunity gene profiles and networks in villous tissue that respond to maternal SARS-CoV-2 infection. Aim 2 will identify spatiotemporal innate immunity gene profiles and networks in fetal membrane and decidual tissue that respond to maternal SARS-CoV-2 infection. A state-of-the-art novel technique of 10x Genomics Visium Gene Expression assay in placental formalin-fixed paraffin embedded (FFPE) tissues combined with RNA-seq will be employed . Placentas from women with active COVID infection, recovered from COVID infection, and received COVID vaccination, etc. will be studied. This novel ideal approach will allow us to map the whole transcriptome with morphological context in placental FFPE tissue and discover the cellular and molecular profiles and networks in different cell types and gene activity at the maternal-fetal interface without disruption of the tissue integrity. Results of the study will provide novel insights into how SARS-CoV-2 infection impacts the innate immune system at the mater-fetal interface, and how the innate immune system at the maternal-fetal interface responds to COVID vaccination during pregnancy, which may help to identify new strategies to prevent COVID-19 infection and reduce maternal and fetal complications in women with COVID-19 infection in the future.