Mechanistic Analysis of Zika Virus Induced Placental Damage During Pregnancy

项目摘要 寨卡病毒（ZIKV）是一种蚊媒黄病毒，最近在西半球爆发， 严重的公共卫生威胁，特别是由于随后的先天性寨卡病毒而对孕妇造成的威胁 在受感染的胎儿中可能出现的综合征。胎盘在胎儿易患 母体病毒感染，但ZIKV后胎盘损伤的时间和机制 感染情况不明。我们利用了妊娠期间ZIKV感染的非人灵长类动物（NHP）模型 证实胎盘氧转运功能异常，这可能限制正常的胎儿器官 发育和易患生长异常。胎盘绒毛透氧性降低 似乎是子宫血管炎、基质细胞死亡和胎盘绒毛损伤的结果。尽管 在妊娠早期和晚期ZIKV感染后的强烈炎症反应，我们已经表明ZIKV 在母体-胎盘-胎儿组织中持续数周至数月，这突出了研究的必要性。 怀孕期间可以采取的预防措施。接种疫苗是一种有效和易处理的策略 用于对抗病毒病原体。怀孕期间的临床限制使最安全的疫苗 利用抗原的平台，包括病毒样颗粒（VLP），这是一种高价值的开发目标。我们 最近通过纯化由表达ZIKV的细胞分泌的VLP，产生了针对ZIKV的基于VLP的疫苗。 ZIKV prM-E多蛋白。 子宫和胎盘巨噬细胞在维持正常妊娠中起关键作用， 显示在细胞培养系统中易受ZIKV的生产性感染。此外，在NHP模型中， 结果显示ZIKV感染后胎盘巨噬细胞表型的变化。我们假设ZIKV 靶向胎盘巨噬细胞，引起急性直接（病毒）和间接（免疫病理学）损伤， 胎盘在发育过程中，激活负责伤口愈合的细胞成分， 胎盘绒毛内的氧化损伤这些诱导的变化导致胎盘血管适应， 以及损害运输并在精神上影响胎儿生长和发育的组织损伤。客观 该提议的一个重要目的是暂时表征ZIKV介导的胎盘功能变化的进展 和组织损伤。我们的纵向方法将有助于表征疾病的发病机制， 结合先进的功能成像和胎儿免疫的时间分析， 反应，感染后的组织转录组学，以及实施一种新的疫苗，以确定是否 接种疫苗可减轻胎盘和胎儿损伤。

PROJECT SUMMARY The recent outbreak of Zika virus (ZIKV), a mosquito-borne flavivirus, in the western hemisphere resulted in a serious public health threat, in particular for pregnant women due to the subsequent Congenital Zika Syndrome which can manifest in infected fetuses. The placenta plays a central role in fetal susceptibility to maternal viral infections yet the timing of, and the mechanisms contributing to, placental injury following ZIKV infection are unknown. We have utilized a nonhuman primate (NHP) model of ZIKV infection during pregnancy to demonstrate functional abnormalities in placental oxygen transport, which likely constrain normal fetal organ development and predispose to growth abnormalities. Decreased oxygen permeability of the placental villi appears to be a consequence of uterine vasculitis, stromal cell death and placental villous damage. Despite a robust inflammatory response following ZIKV infection in both early and late gestation, we have shown that ZIKV persists for weeks to months in maternal-placental-fetal tissues, which highlights the need to investigate preventative strategies that can be employed during pregnancy. Vaccination is an efficient and tractable strategy for combating viral pathogens. The clinical restrictions imposed during pregnancy make the safest vaccine platforms utilizing antigens, which include virus-like particles (VLP), a high value target for development. We have recently generated a VLP-based vaccine against ZIKV by purifying VLP secreted by cells expressing the ZIKV prM-E polyprotein. Uterine and placental macrophages play a key role in maintaining normal pregnancy and have been shown to be susceptible to productive infection by ZIKV in cell culture systems. Moreover, in our NHP model we demonstrated changes in placental macrophage phenotype following ZIKV infection. We hypothesize that ZIKV targets placental macrophages, causes acute direct (viral) and indirect (immunopathological) damage to the placenta during development, which activates cellular components responsible for wound healing and may cause oxidative damage within the placental villous. These induced changes result in placental vascular adaptations, and tissue injury which impairs transport and detrimentally impacts fetal growth and development. The objective of this proposal is to temporally characterize the progression of ZIKV-mediated changes in placental function and tissue damage. Our longitudinal approach will facilitate characterization of disease pathogenesis in both the placenta and fetus by combining advanced functional imaging with temporal profiling of the fetal immune response, tissue transcriptomics following infection, and implementation of a novel vaccine to determine whether vaccination can mitigate placental and fetal injury.