HCMV inhibition of cytotrophoblast differentiation through dysregulation of Wnt/?

描述(申请人提供)：人类巨细胞病毒(HCMV)是一种普遍存在的疱疹病毒，目前感染了世界上很大比例的人口。虽然在免疫功能正常的人中通常没有症状，但在怀孕期间感染巨细胞病毒可能会导致自然流产、早产或在子宫内感染的婴儿永久的神经残疾。在许多情况下，感染的证据是胎盘，而不是胚胎或胎儿。最近的研究表明，HCMV感染抑制了细胞滋养层细胞(CTB)的侵袭，导致浅层胎盘形成。拟议研究的总体目标是确定巨细胞病毒在胎盘形成过程中损害结缔组织结核侵袭的分子机制(S)。在感染期间，病毒对许多宿主信号通路施加控制。我们的初步数据显示，β-连环蛋白的转录活性显著 在HCMV感染的CTBS中被抑制。-连环蛋白是典型的Wnt/-连环蛋白信号通路中的关键因子，最近被证明在胎盘形成过程中对CTB的侵袭分化起关键作用；然而，HCMV对这一通路的影响尚不清楚。需要检验的假设是，HCMV通过对典型的Wnt/β-catenin信号的失调来抑制CTB的分化和功能。目的1利用新近发现的人原代滋养细胞前体细胞(TBPC)和旋转壁血管生物反应器(RWV)技术建立胎盘滋养层细胞分化的体外模型，以确定HCMV感染对滋养层细胞分化早期和晚期的影响，阐明规范的Wnt/β-catenin信号在TBPC分化过程中的重要性，以及HCMV感染对Wnt/β-catenin信号的影响。目标2将定义过氧化物酶体增殖物激活受体γ(PPAR？)和CTB分化过程中的β-连环蛋白途径。PPAR？已被证明可以控制滋养层细胞的侵袭和分化，也可以负向调节β-连环蛋白。被HCMV UL97激活的转录因子E2F1被认为是这些途径的收敛调节的关键。了解HCMV感染CTBS后Wnt/β-catenin信号转导失调的机制可能为减少先天性感染的风险和预防妊娠并发症提供新的预后和治疗方法。

DESCRIPTION (provided by applicant): Human Cytomegalovirus (HCMV) is a ubiquitous herpesvirus that currently infects a large percentage of the world population. Although usually asymptomatic in immunocompetent individuals, HCMV infection during pregnancy may cause spontaneous abortions, premature delivery, or permanent neurological disabilities in infants infected in utero. In many cases, it is the placenta, not the embryo or fetus that shows evidence of infection. Recent studies have demonstrated that HCMV infection inhibits cytotrophoblast (CTB) invasion resulting in shallow placentation. The overall goal of the proposed studies proposed is to determine the molecular mechanism(s) by which HCMV impairs CTB invasion during placentation. During infection, the virus exerts control over a multitude of host signaling pathways. Our preliminary data show that the transcriptional activity of ¿-catenin is significantly inhibited in HCMV infected CTBs. ¿-catenin is the key factor in the canonical Wnt/¿-catenin signaling pathway that has recently been shown to be critical for invasive differentiation of CTBs during placentation; however, the effect of HCMV on this pathway is unknown. The hypothesis to be tested is that HCMV inhibits CTB differentiation and function through dysregulation of canonical Wnt/¿-catenin signaling. Aim 1 will employ an innovative in vitro model of placental trophoblast differentiation employing newly discovered human primary trophoblast progenitor cells (TBPCs) and rotating wall vessel (RWV) bioreactor technology in order to determine the effect of HCMV infection on early and late stages of trophoblast differentiation and demonstrate the importance of canonical Wnt/¿-catenin signaling during TBPC differentiation, and the effect of HCMV infection on Wnt/¿-catenin signaling. Aim 2 will define the molecular crosstalk between peroxisome proliferator-activated receptor gamma (PPAR?) and ¿-catenin pathways during CTB differentiation. PPAR? has been shown to control trophoblast invasion and differentiation, as well as negatively regulate ¿-catenin. The transcription factor E2F1 that is activated by HCMV UL97 is postulated to be key to the convergent regulation of these pathways. An understanding of the mechanisms underlying dysregulation of Wnt/¿-catenin signaling following infection of CTBs by HCMV may provide new prognostic and therapeutic approaches to reduce the risks of congenital infection and prevent complications during pregnancy.