Project 2: Virologic determinants of cCMV

摘要-项目2：胎儿RhCMV传播的病毒决定因素 人巨细胞病毒（HCMV）是新生儿先天性疾病的主要感染原因， 开发治疗和预防措施需要更好地了解病毒 CMV初治和CMV免疫个体中胎儿传播的决定因素。由于HCMV是高度 使用相应动物CMV先天性感染的物种限制性动物模型来研究 先天性感染非人灵长类动物模型的最新进展首次使胎儿发育的研究成为可能。 在解剖学上与人类非常相似的宿主中通过与人类高度同源的病毒传播 巨细胞病毒。因此，本项目的目标是使用该模型来识别和表征病毒决定因素 促进胎儿传播，以最终支持制定具体对策。具体地说， 我们将研究胎儿传播是否与孕妇的病毒血症和病毒传播有关。 女性我们将进一步研究病毒细胞嗜性在胎儿感染中的作用，并研究以下假设： 抗病毒抗体的效力受到病毒Fc受体的限制。为了使基因操作 为了解决这些问题，我们产生了一个细菌人工染色体（BAC）。 克隆代表低传代分离株，并证明了BAC衍生的RhCMV的胎儿传播。 使用这种BAC，我们将利用我们的观察，RhCMV缺乏免疫显性的主要 皮层蛋白pp 65在未经RhCMV感染的小鼠中显示出显著增加的复制和传播。 研究病毒血症和病毒传播在胎儿传播中的作用（目的1）。我们将进一步 通过实验阐明了细胞嗜性决定五聚体糖蛋白复合物的作用 gH/gL/UL 128/UL 130/UL 131 A在母体/胎儿传播中的作用（目的2）。五聚体复合物目前是一种 疫苗开发的主要目标，但初步数据意外地显示， 病毒缺乏这种复合体。最后，我们将确定病毒Fc受体是否限制了 高免疫球蛋白治疗以限制病毒传播（目的3）。该项目将受益于， 影响项目1中所述的研究，需要所有四个核心的服务。我们预计， 该项目将影响预防和治疗CMV疫苗的设计，并将揭示新的 改进基于抗体的治疗的方法。

ABSTRACT – Project 2: Viral determinants of fetal RhCMV transmission Human cytomegalovirus (HCMV) is the leading infectious cause of congenital disease in newborns, and the development of treatments and preventative measures requires a better understanding of the viral determinants enabling fetal transmission in CMV-naïve and CMV-immune individuals. Since HCMV is highly species-restricted, animal models of congenital infection by the corresponding animal CMVs are used to study congenital infection. Recent advances in non-human primate models for the first time enable the study of fetal transmission in a host that is anatomically very similar to humans by a virus that is highly homologous to HCMV. The goal of this project is therefore to use this model to identify and characterize viral determinants facilitating fetal transmission to ultimately support the development of specific countermeasures. Specifically, we will examine whether fetal transmission correlates with viremia and viral dissemination in the pregnant female. We will further examine the role of viral cell tropism in fetal infection and examine the hypothesis that the efficacy of antiviral antibodies is limited by viral Fc receptors. To enable the genetic manipulation of RhCMV that is required to address these questions we generated a bacterial artificial chromosome (BAC) clone representative of a low passage isolate and demonstrated fetal transmission of BAC-derived RhCMV. Using this BAC we will take advantage of our observation that RhCMV lacking the immunodominant major tegument protein pp65 displayed dramatically increased replication and dissemination in RhCMV-naïve animals to examine the role of viremia and viral dissemination in fetal transmission (Aim 1). We will further experimentally address the role of the cell tropism-determining pentameric glycoprotein complex gH/gL/UL128/UL130/UL131A in maternal/fetal transmission (Aim 2). The pentameric complex is currently a major target for vaccine development, but preliminary data unexpectedly revealed increased transmission of virus lacking this complex. Finally, we will determine whether viral Fc-Receptors limit the efficacy of hyperimmunoglobulin treatment to limit viral dissemination (Aim 3). This project will both benefit from and impact the studies described in Project 1 and require the services of all four cores. We anticipate that this project will impact the design of prophylactic and therapeutic CMV vaccines and that it will reveal novel approaches to improve antibody-based therapy.