A model for developmental IFN gene regulation in the virus-infected fetus

描述（由申请人提供）：干扰素（ifn）是一组多功能细胞因子，参与早期胚胎的着床，维持成功妊娠，启动先天免疫和调节适应性免疫反应。最近的猪基因组基因清单鉴定出39个I型，1个II型和2个III型IFN基因。大量来自同一家族的基因的生物学意义表明，IFN的表达受到发育调控，包括病毒感染胎儿时特定类、亚类和亚型的表达上调。拟建项目的目的是分析健康胎儿和病毒感染胎儿中IFN基因受体的表达。该模型系统采用猪生殖与呼吸综合征病毒（PRRSV）动脉病毒自然感染妊娠晚期猪胎儿。目的1是表征IFN类、亚类和亚型在免疫功能猪胎儿中的表达。正在验证的假设是特异性IFN基因在妊娠晚期胎儿中优先表达，并且基因表达模式具有组织特异性。在此目的下，实时RT-PCR阵列用于测量单个猪ifn及其受体的表达。在114天妊娠期的第75天、第85天、第92天、第100天和第110天，在胎儿、界面（胎盘）和母体腔室中进行表达测定。目的2是测量病毒感染期间胎儿IFN基因表达的变化。妊娠猪坝在妊娠85 ~ 90天自然感染PRRSV可导致胎儿感染。具有两个不同端点的两个分离株用于感染。在妊娠112天测量IFN和IFN受体的表达。基因表达模式与病毒血症和prrsv特异性抗体相关。结果将确定参与保护胎儿或可能参与胎儿排斥反应的候选干扰素。目标3是兽医预科（预科）本科生参与研究。体验式学习活动将教授本科生与开发和使用比较动物模型和基本分子实验室技术相关的研究技能。PRRSV感染妊娠晚期胎儿为解剖病毒与其自然宿主之间的相互作用提供了一个相关的模型系统。另一个重要的创新是对免疫功能胎儿中IFN基因表达的分析，这将为研究人类胎儿感染、其后果和潜在治疗方法提供一个重要的比较模型。

DESCRIPTION (provided by applicant): The interferons (IFNs) are a multi-functional group of cytokines that participate in the implantation of the early embryo, maintenance of a successful pregnancy, initiation of innate immunity and regulation of adaptive immune responses. A recent gene inventory of the pig genome identified 39 type I, 1 type II and 2 type III IFN genes. The biological significance of a large number of genes from the same family suggests that IFN expression is developmentally regulated, including the up-regulated expression of specific classes, subclasses and subtypes during viral infection of the fetus. The purpose of the proposed project is to profile the expression of IFN genes in their receptors in healthy and virus-infected fetuses. The model system incorporates the natural infection of the late-gestation pig fetus with an arterivirus, porcine reproductive and respiratory syndrome virus (PRRSV). Aim 1 is to characterize the expression of IFN classes, subclasses and subtypes in the immunocompetent pig fetus. The hypothesis being tested is that specific IFN genes are preferentially expressed in the late gestation fetus and the pattern of gene expression is tissue specific. Under this aim, a real-time RT-PCR array is used to measure the expression of the individual porcine IFNs and their receptors. Expression will be measured in fetal, interface (placenta) and maternal compartments at 75, 85, 92, 100 and 110 days of the 114 day gestation period. Aim 2 is to measure alterations in fetal IFN gene expression during virus infection. Natural infection of the pregnant porcine dam with PRRSV at 85 to 90 days gestation leads to fetal infection. Two isolates that possess two different endpoints are used for infection. IFN and IFN receptor expression will be measured at 112 days of gestation. The pattern of gene expression will be correlated with viremia and PRRSV-specific antibody. The results will identify candidate IFNs that are involved in protecting the fetus or may be involved in fetal rejection. Aim 3 is the participation of pre-veterinary (prevet) undergraduate students into research. The experiential learning activities will teach undergraduate students research skills related to the development and use of a comparative animal model and basic molecular laboratory techniques. PRRSV infection of the late-gestation fetus provides a relevant model system for dissecting the interaction between a virus and its natural host. Another important innovation is the analysis of IFN gene expression in the immunocompetent fetus, which will provide an important comparative model for studies of human fetal infections, their consequences and potential therapies. PUBLIC HEALTH RELEVANCE: This project is the first-of-its-kind analysis of IFN and IFN-gene expression in the immunocompetent pig fetus. The model provides the means to test therapies and other treatments on fetal immunity and identify expression patterns involved in defense and pathogenesis.