Mechanistic Analysis of Zika Virus Induced Placental Damage During Pregnancy

项目总结 最近在西半球爆发的寨卡病毒(ZIKV)，一种蚊媒黄病毒，导致 在严重的公共健康威胁中，特别是对孕妇来说，由于随后的先天性寨卡病毒 可在感染的胎儿中表现出来的综合症。胎盘在胎儿易患风湿性心脏病中起核心作用 母体病毒感染导致ZIKV后胎盘损伤的时间和机制 感染是未知的。我们使用了孕期ZIKV感染的非人灵长类动物(NHP)模型。 显示胎盘氧气转运功能异常，可能抑制正常胎儿器官 发育异常，易发生生长异常。胎盘绒毛的透氧性降低 似乎是子宫脉管炎、间质细胞死亡和胎盘绒毛损伤的结果。尽管有一个 妊娠早期和晚期感染ZIKV后的强烈炎症反应，我们已经证明ZIKV 在母体-胎盘-胎儿组织中持续数周至数月，这突显了调查的必要性 孕期可采用的预防性策略。接种疫苗是一种有效和易处理的策略。 用来对抗病毒病原体。在怀孕期间实施的临床限制是最安全的疫苗 利用抗原的平台，其中包括病毒样颗粒(VLP)，这是一个高价值的开发目标。我们 最近通过纯化表达ZIKV的细胞分泌的VLP产生了一种基于VLP的疫苗 ZIKV PRM-E多聚蛋白。 子宫和胎盘巨噬细胞在维持正常妊娠中起关键作用 在细胞培养系统中显示对ZIKV的生产性感染敏感。此外，在我们的NHP模型中，我们 证实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，造成急性直接(病毒)和间接(免疫病理)损害 胎盘在发育过程中，它激活负责伤口愈合的细胞组件，并可能导致 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， 以及组织损伤，损害运输并有害地影响胎儿的生长和发育。目标是 这一建议的目的是在时间上描述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描述两种疾病的发病机制 结合先进的功能成像和胎儿免疫的时间分布的胎盘和胎儿 反应，感染后的组织转录，以及新型疫苗的实施，以确定 接种疫苗可以减轻胎盘和胎儿的损伤。

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.