The RNA interactome necessary and sufficient for Orbivirus genome packaging

正如目前SARS-CoV-2爆发的情况所表明的那样，病毒感染对生物圈构成了始终存在的威胁，最终会造成人员伤亡或经济受损。在所有感染性生物中，病毒是控制得最差的，因为它们的复制与宿主的复制密切相关，而且对病毒特有成分的定义通常非常具有挑战性，正如开发细菌抗生素所做的那样。一旦病毒感染宿主细胞（人类、动物或植物），复制就会迅速启动，病毒复制宿主细胞的蛋白质和基因组，并将它们组装成后代病毒，以便传播。抑制这一进程的理想目标是同一家族的所有成员绝对需要和共有的目标。其中一个过程就是基因组组装。病毒的合成过程只有在病毒基因组以正确的形式被整合到新生的子代中才有可能，如果基因组是多片段的，病毒就特别难以整合基因组，这是许多令人关注的病毒（例如流感病毒）的情况。如果要在病毒如何繁殖和传播方面取得进展，了解不同序列的多个基因组片段如何以正确的顺序和形式结合是至关重要的。这些信息的缺乏造成了多年来对许多病毒的研究和理解的瓶颈。该项目的重点是一种动物病毒，蓝舌病病毒（BTV），一种绵羊和牛的著名病原体。BTV及其相关病毒对动物和人类具有高致病性，BTV杀死牲畜，造成毁灭性的经济后果。这些病毒的特征是它们的10或11个基因组RNA片段，每个片段代表一个基因，每个片段产生特定的病毒蛋白质。该项目将研究在复制周期中新RNA片段如何融入病毒颗粒的最重要过程，这将为设计干预和开发用于控制疾病的减毒疫苗提供新的机会。此外，对这一基本过程的理解也为RNA生物学奠定了基础，并影响了广泛的应用，从理解RNA疾病到开发先进疗法（将新型RNA纳入病毒中以进行基因传递和基因治疗）。由于之前BBSRC资助的项目，我们开发了独特的工具，技术和试剂，因此该小组处于这一研究领域的前沿。通过一系列新的分析系统，我们已经确定了BTV如何招募它们的片段并组装成具有传播能力的活病毒的一些基本步骤。选择和包装的精确性质，即获得十个片段中的每一个片段的一个副本，而不是一个片段的多个副本，是一个复杂和高度调控的过程，因为病毒必须区分细胞和病毒基因。在对有关病原体进行基础研究的基础上，长期改善动物福利是很重要的。BTV在某些家畜中具有高致病性，最近在英国和欧洲出现。了解病毒基因组生命周期中这些至关重要的基本过程，将有可能开发出针对蓝舌病和其他影响牲畜的病毒性疾病的新型、更安全的设计疫苗。这些数据还将有助于开发新的干预措施，以改善未来的疾病管理。

As the current situation with the outbreak of SARS-CoV-2 demonstrates, virus infections represent an ever-present threat to the biosphere which ultimately has a human cost in terms of lives lost or economies compromised. Of all infectious organisms, viruses are the least well controlled as their replication is intimately tied-up with that of the host and the definition of components that are unique to the virus, as has been done for the development of antibiotics for bacteria, is often very challenging. Once viruses infect a host cell (human, animal or plant) replication is rapidly initiated and the virus makes copies of its proteins and genome and assembles them into progeny viruses in order to spread. An ideal target to inhibit this process would be one which is absolutely required and shared by all members of the same family. One such process is that of genome assembly. The process of virus synthesis is only possible if the viral genome is incorporated into nascent progeny in the correct form and it is particularly difficult for viruses to incorporate the genome if it is in multiple pieces, which is the case for many viruses of concern (e.g. influenza virus). Understanding how multiple pieces of genomes, each of a different sequence, are incorporated in the correct order and form is essential if progress is to made on how viruses multiply and spread. The lack of this information has created a bottleneck in the research and understanding of many viruses over the years. This project focuses on an animal virus, Bluetongue virus (BTV), a notable pathogen of sheep and cattle. BTV and related viruses are highly pathogenic in animals and humans with BTV killing livestock with devastating economic consequences. The viruses are characterized by their 10 or 11 genomic pieces of RNA known as genomic segments, each representing a single gene and each generating specific viral proteins. This project will investigate the most vital process of how new RNA pieces are incorporated into the virus particle during the replication cycle, which will offer new opportunities for designed intervention and the development of attenuated vaccines for the control of disease. Further, the understanding of this fundamental process also underpins much RNA biology and impinges on a wide range of applications, from understanding RNA disease to the development of advanced therapies in which novel RNAs are incorporated into viruses for the purposes of gene delivery and gene therapy.The group is exceptionally positioned at the forefront of this field of research as a result of previous BBSRC funded projects in which we developed unique tools, techniques and reagents. With a series of novel assay systems we have already defined some of the essential steps of how BTV may recruit their segments and assemble into a viable virus, competent for spreading. The precise nature of selection and packaging, that is acquiring a single copy of each of ten segments rather than multiple copies of one, is a complex and highly regulated process as the virus must differentiate between cellular and viral genes. Long term improvements in animal welfare underpinned by basic research into the pathogen concerned are important. BTV is highly pathogenic in certain livestock and has recently emerged in the UK and Europe. Understanding these vital basic processes in the life cycle of the viral genome will make it possible to develop novel, safer designer vaccines for Bluetongue disease and may be other viral diseases that affect livestock. The data will also allow for the development of novel interventions to improve future disease management.