Placental trophoblast infection and TLR mediated response to congenital CMV

描述(由申请人提供)：开发有效的干预策略来预防先天性巨细胞病毒(CMV)是一项重要的公共卫生优先事项。然而，在临床前动物模型中，候选CMV疫苗策略在完全预防先天性感染方面一直不成功，有效的疫苗仍然是一个难以实现的目标。CMV经胎盘感染的致病性尚不明确，更好的理解可能会为开发新的干预措施或疫苗策略提供新的见解。在这个提案中，我们将研究胎盘感染的两个关键方面：(1)Toll样受体(TLR)介导的胎盘对CMV的先天免疫反应；(2)病毒嗜性和胎盘感染。胎盘关键细胞(滋养层细胞)上表达的TLRs介导的炎性先天免疫反应是控制细菌和病毒先天性感染胎盘侵袭的一个重要方面。已知CMV可被多个TLR识别，但胎盘TLR介导的对CMV的应答尚不清楚，CMV潜在地绕过胎盘天然免疫并在宫内感染胎儿的机制尚不清楚。我们的假设是，成功的先天性感染依赖于CMV的能力 为了有效地进入和篡夺表达TLR的滋养层细胞，滋养层细胞是胎盘屏障和胎盘先天免疫的重要组成部分。新近发现的病毒进入细胞的内吞途径可能是导致胎盘侵入和滋养层细胞感染的重要因素。我们建议在唯一的先天性巨细胞病毒的小动物模型(豚鼠)中，确定TLR介导的胎盘对巨细胞病毒感染的先天免疫反应的意义。此外，使用相同的动物模型，我们将定义重要的趋向性基因，这些基因可能使病毒在胎盘中建立感染灶，并随后感染子宫内的胎儿。这些研究将使用传统的组织病理学和免疫组织化学方法以及新技术，包括使用动物模型中病毒传播的生物发光成像。 公共卫生相关性：巨细胞病毒(CMV)是一种普遍存在的病原体，在免疫受损人群中会导致大量死亡和发病，包括移植和艾滋病患者以及宫内胎儿。先天性巨细胞病毒感染会导致存活新生儿的智力低下和耳聋。巨细胞病毒是艾滋病最常见的继发性感染。目前还没有针对CMV的疫苗。尽管目前的抗病毒药物可用于移植和艾滋病患者，但这些药物会导致出现导致疾病的耐药菌株。此外，药物的毒副作用使其不能用于预防先天性巨细胞病毒。

DESCRIPTION (provided by applicant): Development of an effective intervention strategy against congenital cytomegalovirus (CMV) is a major public health priority. However, candidate CMV vaccines strategies have been unsuccessful in completely preventing congenital infection in a pre-clinical animal model and an effective vaccine remains an elusive goal. The pathogenicity of CMV transplacental infection is poorly defined and a better understanding may provide fresh insight for the development of a novel intervention or vaccine strategy. In this proposal, we will examine two key aspects of placental infection: (1) Toll-like receptor (TLR) mediated innate immune response of the placenta to CMV; (2) Viral tropism and placental infection. The inflammatory innate immune response mediated via TLRs expressed on key placental cells (trophoblasts) is potentially an important aspect of controlling placental invasion congenital infection by both bacteria and viruses. CMV is known to be recognized by multiple TLRs but the placental TLR mediated response to CMV is poorly defined as is the mechanism by which CMV potentially circumvents the placental innate immunity and infects the fetus in utero. It is our hypothesis that successful congenital infection is reliant upon the ability of CMV to efficiently enter and usurp TLR expressing trophoblast cells, an important component of the placental barrier and placental innate immunity. Potentially, the newly identified endocytic pathway of viral cell entry could be an important factor in the invasion of the placenta and infection of epithelial trophoblasts. We propose to determine the significance of the TLR mediated innate immune response of the placenta to CMV infection in the only small animal model (guinea pig) for congenital CMV. Additionally, using the same animal model, we will define important tropism genes that potentially enable the virus to establish infectious foci in th placenta and subsequently infect the fetus in utero. These studies will employ conventional histopathological and immunohistochemical approaches as well as novel techniques including the use of bioluminescence imaging of viral dissemination in the animal model. PUBLIC HEALTH RELEVANCE: Cytomegalovirus (CMV) is a ubiquitous pathogen that causes significant mortality and morbidity in immunocompromised populations including transplant and AIDS patients and the fetus in utero. Congenital CMV infection causes mental retardation and deafness in surviving newborn. CMV is the most common AIDS related secondary infection. There is no vaccine to CMV. Although current antivirals are available for transplant and AIDS patients these result in the emergence of resistant strains that cause disease. Additionally, drug toxic side effects preclude their use in the prevention of congenital CMV.