Evolutionary potential of a model poxvirus

描述(由申请人提供)：病原体产生各种各样的因子，这些因子与宿主成分相互作用，促进感染。许多这样的因子类似或模仿宿主蛋白。参与这些宿主-病原体相互作用的蛋白质是基因组中进化最快的一些因素。然而，人们对这种快速进化对宿主-病原体关系的影响知之甚少。这项研究计划旨在通过专注于模型痘病毒-牛痘病毒来检查相互作用的宿主和病原体蛋白的快速进化。目标1将于项目的K99阶段完成，研究一种名为K3L的快速进化的痘病毒蛋白的起源和进化，该蛋白模仿抗病毒蛋白激酶R(PKR)的底物来破坏抗病毒活性。进化分析将指导重建祖先的K3L变体，而细胞分析和实验性病毒感染将测试这些重建的进化步骤的效力。目的2研究K3L在人类致病原天花中的进化。关于K3L对啮齿动物PKR的敏感性的实验将检验天花是从特定的啮齿动物宿主中产生的假设。该计划的目标3需要在不同的宿主细胞系中进行痘苗病毒的实验进化。痘苗病毒将在受控条件下在细胞系中反复传代，并监测基因组变化和潜在的适应能力。这一目标和目标2将在项目的K99阶段启动，并将提供关于相互作用的宿主和病原体因素之间的进化适应的广泛数据。这些实验产生的数据将成为目标3中提议的继续项目的基础，这些项目将在项目的独立阶段进行。该计划的所有实验目标都将培养建立独立研究实验室的重要技能。这种对相互作用的宿主和病原体因子之间的进化动力学的研究将为痘病毒的进化策略提供新的见解，痘病毒是一类潜在的危险病原体，有望成为自然流行病和/或用作生物恐怖主义的代理人。 公共卫生相关性：痘病毒是感染动物和人类的大型DNA病毒。天花是疾病控制中心的高威胁(A类)病原体，猴痘可能会对人类人群造成流行性感染。这个项目采用进化的方法来理解痘病毒如何适应利用它们的宿主，以便这些进化策略可能被抵消，以保护人类健康。

DESCRIPTION (provided by applicant): Pathogens produce an enormous variety of factors that interact with host components to promote infections. Many such factors resemble or mimic host proteins. Proteins involved in these host-pathogen interactions are some of the most rapidly evolving factors in genomes. Yet little is known about the consequences of this rapid evolution on host-pathogen relationships. This research program aims to examine rapid evolution of interacting host and pathogen proteins by focusing on the model poxvirus, vaccinia. Aim 1, which will be completed in the K99 phase of the project, investigates the origins and evolution of a fast evolving poxvirus protein called K3L that mimics the substrate of the anti-viral Protein kinase R (PKR) to disrupt anti-viral activity. Evolutionary analysis will guide the reconstruction of ancestral K3L variants, while cellular assays and experimental viral infections will test the potency of these reconstructed evolutionary steps. Aim 2 investigates the evolution of K3L from smallpox, a devastating human pathogen. Experiments focusing on K3L sensitivity to PKR from rodents will test the hypothesis that smallpox emerged from a specific rodent host. Aim 3 of this program entails experimental evolution of vaccinia virus in different host cell lines. Vaccinia will be repeatedly passaged in cell lines under controlled conditions and monitored for genomic changes and potential adaptations. This aim, along with Aim 2, will be initiated during the K99 phase of the project, and will provide extensive data on evolutionary adaptations between interacting host and pathogen factors. The data generated from these experiments will be the foundation of continuing projects proposed in Aim 3 that will be conducted during the independent phase of the project. All the experimental aims of this program will develop important skills for establishing an independent research laboratory. This investigation of the evolutionary dynamics between interacting host and pathogen factors will provide new insights into the evolutionary strategies of poxviruses, a potentially dangerous class of pathogens poised for natural epidemics and/or use as agents of bio-terrorism. Public Health Relevance: Poxviruses are large DNA viruses that infect animals and humans. Smallpox is a Center for Disease Control high-threat (Category A) agent and monkeypox may be poised for epidemic infections of human populations. This project takes an evolutionary approach to understanding how poxviruses adapt to exploit their hosts, so that these evolutionary strategies might be counteracted for the protection of human health.