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，病毒感染是对生物圈的一种永远存在的威胁，最终会造成生命损失或经济受损。在所有感染性生物体中，病毒是最不受控制的，因为它们的复制与宿主的复制密切相关，并且病毒特有的组分的定义（如针对细菌的抗生素的开发所做的那样）通常非常具有挑战性。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，病毒会复制其蛋白质和基因组，并将其组装成子代病毒，以便传播。抑制这一进程的理想目标是一个家庭的所有成员绝对需要和共享的目标。一个这样的过程是基因组组装。只有当病毒基因组以正确的形式整合到新生子代中时，病毒合成过程才是可能的，并且如果基因组是多个片段，则病毒特别难以整合基因组，这是许多关注病毒（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，就必须了解基因组的多个片段（每个片段都有不同的序列）是如何以正确的顺序和形式整合的。这些信息的缺乏已经在多年来对许多病毒的研究和理解中形成了瓶颈。该项目的重点是一种动物病毒，蓝舌病病毒（BTV），一种值得注意的绵羊和牛的病原体。BTV和相关病毒在动物和人类中具有高致病性，BTV杀死牲畜，造成毁灭性的经济后果。这些病毒的特征在于它们的10或11个被称为基因组片段的RNA基因组片段，每个片段代表单个基因，每个片段产生特定的病毒蛋白。该项目将研究新RNA片段如何在复制周期中并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支持了许多RNA生物学，并影响了广泛的应用，从了解RNA疾病到开发先进的治疗方法，其中新的RNA被纳入病毒中用于基因递送和基因治疗。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。通过一系列新的检测系统，我们已经确定了BTV如何招募它们的片段并组装成一个有能力传播的活病毒的一些基本步骤。选择和包装的确切性质，即获得十个片段中每一个的单个拷贝，而不是一个片段的多个拷贝，是一个复杂且高度调控的过程，因为病毒必须区分细胞和病毒基因。通过对相关病原体的基础研究，长期改善动物福利是重要的。BTV在某些牲畜中具有高致病性，最近在英国和欧洲出现。了解病毒基因组生命周期中这些重要的基本过程将使开发新的，更安全的蓝舌病疫苗成为可能，可能是影响牲畜的其他病毒性疾病。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.