Evolution and mechanisms of cytomegalovirus antagonism of host cell defenses

巨细胞病毒拮抗宿主细胞防御的进化和机制

• 批准号: 10376227
• 负责人: ADAM P. GEBALLE
• 金额: $ 44.01万
• 依托单位: FRED HUTCHINSON CANCER CENTER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10376227
• 关键词: African Green Monkey; Alleles; Amino Acids; Binding; Cebidae; Cells; Cercopithecidae; Clinical; Codon Nucleotides; Complement; Conflict (Psychology); Consequentialism; Cyclic AMP-Dependent Protein Kinases; Cytomegalovirus; Cytomegalovirus Infections; DNA; DNA Viruses; Defect; Disease; Dissection; Endothelium; Epithelial; Event; Evolution; Experimental Models; Fibroblasts; Gene Amplification; Gene Duplication; Gene Family; Genes; Genetic; Genetic Recombination; Genome; Genomics; Goals; High-Throughput DNA Sequencing; Horizontal Gene Transfer; Host Defense; Hot Spot; Human; IRS1 gene; Immunocompromised Host; Infection; Integration Host Factors; Interferons; Life; Measures; Mediating; Medical; Modeling; Molecular; Mutate; Mutation; Neurofibromin 2; Neurologic; Neurologic Deficit; Pathogenesis; Pathway interactions; Patients; Phenotype; Phosphotransferases; Physiological; Play; Predisposition; Process; Protein Biosynthesis; Protein Region; Proteins; RNA; Research; Rhesus; Role; Saimiri; Serial Passage; Side; Signal Transduction; Site; Structure; System; Techniques; Testing; Transgenes; Transgenic Organisms; Variant; Viral; Viral Genome; Viral Proteins; Virus; Virus Diseases; Virus Replication; antagonist; arms race; cell type; disability; experimental study; immune system function; improved; infant infection; inflammatory milieu; inhibitor; insight; monocyte; mutant; mutation screening; neonatal infection; nonhuman primate; overexpression; preference; pressure; prevent; protein kinase R; response; viral fitness

Project Summary/Abstract Human cytomegalovirus (HCMV) causes life-threatening diseases in patients with poor immune system function and long-lasting neurological disabilities in congenitally-infected newborns. In addition to its medical importance, HCMV and related viruses provide a powerful experimental model for investigating how viruses evolve to elude host cell defense systems. The long-term goal of this research is to discover evolutionary and molecular mechanisms by which viruses like HCMV control the host cell's protein synthesis machinery to allow viral replication. One of the defense systems that inhibits many viruses is mediated by protein kinase R (PKR). HCMV encodes two protein antagonists of PKR, TRS1 and IRS1, at least one of which is absolutely essential for the virus to replicate in human cells. Aim 1 seeks to understand why HCMV, like several other large DNA viruses, has two genes that serve the same function. Studies of mutant viruses that have only one of the genes will be used to determine why viruses lacking TRS1 have a replication defect not observed with viruses lacking just IRS1. Other experiments will reveal whether the combination of both genes confers a benefit to the virus under conditions that more closely model natural infections than previous studies, such as when clinical strains of HCMV infect different types of cells, and when they encounter an inflammatory environment. Aim 2 will elucidate mechanisms by which CMV can adapt to overcome PKR using gene duplication and horizontal gene transfer, two processes that have had major impacts on the evolution of large DNA viruses. Aim 3 will dissect how a domain in PKR that is critical for its activity has adapted to maintain its function in defending the host, while changing enough to evade viral factors. Comparisons of variants of this domain in humans, Old World monkeys, and New World monkeys, using the powerful technique of “deep mutational scanning” in which each amino acid in a protein is mutated to all of the other 19 alternatives, will reveal how this region of PKR has evolved and how in turn CMVs have evolved to adapt to the changes. These studies will reveal insights into the mechanisms and evolution of both viral and host factors that are in conflict and that determine whether the virus replicates or is successfully blocked by host defenses.

项目摘要/摘要 人类巨细胞病毒（HCMV）导致免疫系统差的患者威胁生命的疾病 原始感染的新生儿的功能和持久的神经系统疾病。除了医疗 重要性，HCMV和相关病毒提供了一个强大的实验模型，用于研究病毒的方式 演变为洗脱宿主细胞防御系统。这项研究的长期目标是发现进化和 HCMV等病毒控制宿主细胞的蛋白质合成机制以允许的分子机制 病毒复制。抑制许多病毒的防御系统之一是由蛋白激酶R（PKR）介导的。 HCMV编码PKR，TRS1和IRS1的两个蛋白拮抗剂，其中至少一个绝对必不可少 使病毒在人类细胞中复制。 AIM 1试图理解为什么HCMV，就像其他几个大型DNA一样 病毒具有两个具有相同功能的基因。仅具有其中一个基因的突变病毒的研究 将用于确定为什么缺乏TRS1的病毒具有复制缺陷，而缺乏病毒 只是IRS1。其他实验将揭示两个基因的组合是否供应病毒有益 在比以前的研究更紧密地模拟自然感染的条件下，例如临床菌株 HCMV感染了不同类型的细胞，以及遇到炎症环境时。 AIM 2意志 阐明CMV可以使用基因复制和水平来克服PKR的机制 基因转移，两个对大型DNA病毒进化产生重大影响的过程。目标3意志 剖析PKR中对其活动至关重要的域如何适应其功能 捍卫宿主，同时改变足以逃避病毒因素。比较该域的变体 在人类，旧世界猴子和新世界猴子中，使用强大的“深突变技术” 扫描”，其中蛋白质中的每个氨基酸都被突变为其他所有19种替代方案，将揭示如何 PKR区域已经发展，CMV又如何发展以适应变化。这些研究会 揭示有关冲突的病毒和宿主因素的机制和演变的见解， 确定该病毒是复制还是成功地被宿主防御阻塞。