The Molecular Determinants of Virus Induced Biliary Atresia

描述（由申请人提供）：胆道闭锁是小儿终末期肝病的最常见原因，也是小儿肝移植的首要适应症。由于在患病儿童的肝脏中发现了致病病毒，因此提出的胆道闭锁病因是围产期病毒感染引发免疫介导的胆道上皮破坏。胆道闭锁的小鼠模型支持病毒发病机制，因为感染恒河猴轮状病毒（RRV）的新生小鼠会在汇管道内发生炎症并导致肝外胆管阻塞。 RRV 以胆管细胞为目标进行感染，除了直接损伤胆管细胞外，还诱导 T 细胞介导的胆管上皮损伤。 轮状病毒是一种双链RNA病毒，由11个基因片段组成。我们假设特定的轮状病毒基因控制感染胆管细胞并诱导免疫介导损伤的能力。为了检验这一假设，我们生成了一套完整的源自亲本菌株 RRV 和 TUCH 的单基因重配体。这些重配体为我们提供了一套独特的工具来确定特定轮状病毒基因如何促进发病机制。在初步研究中，我们发现RRV片段3、4、6、8、9和11是感兴趣的基因。鉴于对基因片段 4 进行观察的稳健性，我们重点关注该基因。我们将使用 RRV（胆管细胞感染和 T 细胞激活）的体外模型来确定基因片段 4 导致疾病发病机制的机制。我们还将利用反向遗传学来生成突变基因片段4的感染性病毒，以确定在完整宿主的更复杂环境中的基础。这些互补的方法将为病毒引起的胆道闭锁产生新的见解。

DESCRIPTION (provided by applicant): Biliary atresia is the most common cause of pediatric end stage liver disease and the number one indication for pediatric liver transplantation. Because pathogenic viruses have been found in the liver of afflicted children, a proposed etiology for biliary atresia is a perinatal viral infection triggering immune mediated destruction of the biliary epithelium. The murine model of biliary atresia supports a viral pathogenesis as newborn mice infected with rhesus rotavirus (RRV) develop inflammation within the portal tract and extra- hepatic bile duct obstruction. RRV targets the cholangiocyte for infection and in addition to direct cholangiocyte injury also induces T-cell mediated injury to the biliary epithelium. Rotavirus is a dsRNA virus comprised of 11 gene segments. We hypothesized that specific rotavirus genes govern the ability to infect the cholangiocyte and induce immune mediated injury. To test this hypothesis, we generated a complete set of single gene reassortants derived from the parental strains RRV and TUCH. These reassortants give us a unique set of tools to determine how specific rotavirus genes contribute to the pathogenesis. In preliminary studies, we found that RRV segments 3, 4, 6, 8, 9 and 11 are genes of interest. Given the robust nature of the observations made with gene segment 4, we focused on this gene. We will use in vitro models of RRV - cholangiocyte infection and T-cell activation to determine the mechanisms by which gene segment 4 contributes to disease pathogenesis. We will also use reverse genetics to generate mutate gene segment 4 infectious virus to determine the basis in the more complex environment of the intact host. These complimentary approaches will generate new insight in viral induced biliary atresia.