Elucidation of novel pathways components of C. elegans viral immunity

阐明秀丽隐杆线虫病毒免疫的新途径成分

• 批准号: RGPIN-2014-04578
• 负责人: Pio, Frederic
• 金额: $ 2.55万
• 依托单位: Simon Fraser University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=629482
• 关键词: Elucidation; novel; pathways; components; C.

This research program represents a new direction in my laboratory towards the discovery of novel pathways involved in viral innate-immunity using C. elegans as a model organism that build from preliminary data obtained by undergraduate students in my laboratory. The pathways of interest are currently unknown in the worm, but exist in vertebrates. Their discovery in C. elegans would provide an important advance in knowledge in this model organism that would give us novel insights into the conservation of these processes during evolution and therefore, their importance in vertebrates. The C. elegans innate immune system is remarkably efficient at distinguishing non-pathogenic from pathogenic bacteria. But its genome does not contain the important pathway components that are involved in viral immune response for infection in mammalian. In vertebrates the innate immune response is mounted by specific receptors that recognize viral nucleic-acids called Pathogens Recognition Receptors (PRR). These receptors recognize viral nucleic acids by a binding domain called Oligonucleotide Binding domain (OB). During infection these PRR recognize viral nucleic-acids and as a result a series of signaling events take place to up regulate anti-viral mechanisms. In C. elegans these PRR’s as well as the molecular components that activate the viral immune response are unknown and it remains to be discovered if some members of the OB fold family in C. elegans are PRR. We have established in my laboratory the C. elegans infection system by the dsRNA Orsay virus. We can now use reverse genetics tools that have been extensively developed for this model organism and from which many reagents can be made available to us to identify the pathways components activated by this virus.Long term: Our long term goal is to identify the molecular components of the unknown viral immunity pathways activated by orsay virus infection in the model organism C. elegans. We may reveal an ancient dsRNA antiviral immune pathway that is currently unknown and possibly conserved in animals. Short term: The current program can be described by two shorter objectives. (i) Determine the role of the OB fold in C. elegans infected by nodavirus orsay. Which OB fold are the pattern recognition receptors of the orsay-virus nucleic-acids that trigger the immune response in C. elegans . Do they exist? We will use OB fold knockdown strains and/or transgenic line over-expressing OB gene promotor or coding region to determine if the virus interfere with gene expression for some of these genes. (ii) Determine which antiviral host effectors are regulated as a result of pathway activation after orsay virus infection. We will use RNA sequencing techniques to profile differentially expressed genes between infected and non infected strains.Impact : The proposed research in objective 1 may identify the unknown Pattern Recognition Receptor(s) that are mounting the viral immune response in C. elegans. Identifying them is an important advance in basic knowledge of this organism. Objective 2 will give insight into how C. elegans mounts the innate immune response against viral infection, despite having few of the known vertebrate pathway components. The identification of components of such a novel signaling cascade has real potential for the discovery of novel antiviral effectors and regulators in vertebrates. These novel features of viral innate immune response may be an ancient mechanism evolutionarily conserved within vertebrates. Further studies on these effectors and regulators could lead to candidate targets for novel antiviral and anti-inflammatory therapies as well as new biomarkers for infection that may have been missed in vertebrates.

该研究项目代表了我的实验室的一个新方向，即使用秀丽隐杆线虫作为模型生物，根据我实验室本科生获得的初步数据，发现涉及病毒先天免疫的新途径。感兴趣的途径目前在蠕虫中未知，但存在于脊椎动物中。他们在秀丽隐杆线虫中的发现将为这种模式生物的知识提供重要的进步，这将使我们对进化过程中这些过程的保护以及它们在脊椎动物中的重要性有新的见解。线虫先天免疫系统在区分非致病菌和致病菌方面非常有效。但其基因组不包含参与哺乳动物感染病毒免疫反应的重要途径成分。在脊椎动物中，先天免疫反应是由识别病毒核酸的特定受体（称为病原体识别受体（PRR））发起的。这些受体通过称为寡核苷酸结合域（OB）的结合域识别病毒核酸。在感染过程中，这些 PRR 识别病毒核酸，从而发生一系列信号事件来上调抗病毒机制。在线虫中，这些 PRR 以及激活病毒免疫反应的分子成分尚不清楚，并且线虫中 OB 折叠家族的某些成员是否具有 PRR 仍有待发现。我们在我的实验室建立了双链RNA奥赛病毒的线虫感染系统。我们现在可以使用针对该模式生物广泛开发的反向遗传学工具，从中可以使用许多试剂来识别该病毒激活的途径成分。 长期：我们的长期目标是鉴定模式生物线虫中奥赛病毒感染激活的未知病毒免疫途径的分子成分。我们可能会揭示一种古老的 dsRNA 抗病毒免疫途径，该途径目前未知，并且可能在动物中保守。短期：当前计划可以用两个较短的目标来描述。 (i) 确定 OB 折叠在诺达病毒 orsay 感染的线虫中的作用。 OB 折叠是奥赛病毒核酸的模式识别受体，可触发线虫的免疫反应。它们存在吗？我们将使用 OB 折叠敲低菌株和/或过表达 OB 基因启动子或编码区的转基因系来确定病毒是否干扰其中一些基因的基因表达。 (ii) 确定哪些抗病毒宿主效应器因奥赛病毒感染后途径激活而受到调节。我们将使用 RNA 测序技术来分析感染菌株和未感染菌株之间的差异表达基因。影响：目标 1 中拟议的研究可能会识别出在线虫中引发病毒免疫反应的未知模式识别受体。识别它们是该生物体基础知识的重要进步。目标 2 将深入了解秀丽隐杆线虫如何启动针对病毒感染的先天免疫反应，尽管已知的脊椎动物途径成分很少。鉴定这种新型信号级联的成分对于在脊椎动物中发现新型抗病毒效应器和调节器具有真正的潜力。病毒先天免疫反应的这些新特征可能是脊椎动物进化上保守的一种古老机制。对这些效应器和调节器的进一步研究可能会产生新型抗病毒和抗炎疗法的候选靶点，以及脊椎动物中可能被遗漏的感染的新生物标志物。