ROLE OF RHESUS ROTAVIRUS GENE 4 IN BILIARY ATRESIA

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 胆道闭锁(BA)是一种严重危害儿童健康的疾病。BA的病因仍然不确定；然而，越来越多的证据支持病毒成分在疾病发病机制中的作用。BA小鼠模型是由围产期感染恒河猴轮状病毒(RRV)引起的，而不是由其他轮状病毒株诱导的，Tuch就是一个例子。轮状病毒是一种双链RNA病毒，包含11个基因片段。为了确定哪个RRV基因片段对疾病的致病起作用，我们利用亲本株RRV和TUCH，以及轮状病毒的重排特性，产生了一套完整的单基因重组体。产生了11个单基因“功能丧失”重组体和11个互换的单基因“功能获得”重组体，在这些重组体中，一个TUCH基因取代了其RRV等价物。用“功能丧失”重组体RT4感染小鼠，其中来自TUCH的基因片段4被置于RRV背景上，消除了RRV引起小鼠BA的能力。相反，“功能增益”重组子TR4导致了小鼠BA，死亡率为95%。与RRV相比，RRV在体内和体外的RT4结合率和滴度均显著降低，TR4结合率和滴度显著高于TUCH。重组体RT3和TR3诱导了一种中间表型。基因片段4通过其翻译的基因产物VP4调节RRV对胆管上皮细胞的趋向性，并诱导小鼠胆道闭锁模型。趋向性的基础及其如何引起胆道梗阻需要进一步研究。RRV基因片段3的替换在体外不影响病毒的感染性，但改变了体内的作用。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Biliary atresia (BA) is a devastating disease of childhood. The etiology of BA remains uncertain; however, increasing evidence supports a viral component in disease pathogenesis. The murine model of BA is induced by perinatal infection with rhesus rotavirus (RRV) but not by other strains of rotavirus an example of which is TUCH. Rotavirus is a double-stranded RNA virus that contains 11 gene segments. To determine which RRV gene segment is responsible for disease pathogenesis, we used the parental strains RRV and TUCH and the rotavirus property of reassortment to generate a complete set of single gene reassortants. Eleven single-gene "loss-of-function" reassortants in which a TUCH gene replaced its RRV equivalent and eleven reciprocal single gene "gain-of-function" reassortants in which a RRV gene replaced its TUCH equivalent were generated. Infection of mice with the "loss-of-function" reassortant RT4 where gene segment 4 from TUCH was placed on an RRV background eliminated RRV's ability to cause murine BA. In a reciprocal fashion, the "gain-of-function" reassortant TR4 resulted in murine BA with a mortality rate of 95%. Cholangiocyte binding and infectivity assays revealed RT4 binding ratio and titer (both in vivo and in vitro) were significantly attenuated as compared with RRV; moreover, TR4 binding and titer were significantly higher than TUCH. Reassortant RT3 and TR3 induced an intermediate phenotype. Gene segment 4 through its translated gene product VP4 plays a significant role governing RRV tropism for the biliary epithelial cell and induces the murine model of biliary atresia. The basis for tropism and how it induces biliary obstruction requires further study. Substitution of RRV gene segment 3 did not affect viral infectivity in vitro, but altered the in vivo effect.