5' End Genomic Deletions and Enterovirus Persistence

5 端基因组缺失和肠道病毒持久性

• 批准号: 7885216
• 负责人: Nora M. Chapman
• 金额: $ 29.22万
• 依托单位: UNIVERSITY OF NEBRASKA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-01-15 至 2012-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7885216
• 关键词: Acute; Adult; Affect; Binding; Binding Sites; Biology; Cell Culture Techniques; Cell Nucleus; Cells; Child; Chronic; Chronic Disease; Complement component C1s; Complex; Coxsackie B Viruses; Cytoplasm; Dilated Cardiomyopathy; Disease; Enterovirus; Enterovirus Infections; Environment; Etiology; Event; Face; Family Picornaviridae; Generations; Genome; Genomics; Goals; Growth; Heart; Higher Order Chromatin Structure; Human; Human poliovirus; Immune; Immune response; Infection; Knowledge; Laboratories; Lead; Life Style; Link; Long-Term Effects; Lytic; Mus; Mutate; Myocarditis; Neurologic; Nuclear; Nucleotides; Pancreatic Diseases; Polioviruses; Population; Primary Cell Cultures; Process; Production; Proteins; RNA; RNA Viruses; RNA chemical synthesis; RNA replication; Reporting; Role; Serotyping; Site; Time; Tissues; Variant; Viral; Viral Physiology; Virion; Virus; Work; base; fascinate; heart function; human disease; insight; novel; protein structure; public health relevance; sound; viral RNA; viral detection

DESCRIPTION (provided by applicant): The mutable RNA viruses are marvelously successful at adapting to exploit new environments. We will explore just such a newly discovered adaptation in this project, determining how the loss of a genomic region that is vital to replicational efficiency, allows an enterovirus to adapt to a different intracellular environment. Enteroviruses have been viewed as characteristically rapidly lytic, causing short-term infections. However, the discovery that group B coxsackieviruses (CVB) can delete sequence from the genomic 5' terminus (TD), yet maintain function and most importantly, persist for long periods of time post-infection in the heart or cell culture, has provided the grist with which to challenge that traditional view. Given that the 5' terminus of enterovirus RNA is involved in numerous functions for viral replication, deletion of as many as 49 nucleotides from the 5' end of the genome should be a dire event for the virus and indeed, it is. Among other things, viral replication slows dramatically and crippled positive strand RNA synthesis results in near 1 to 1 levels of positive to negative viral RNA in infected cells. The objective of this proposal is to characterize the role of hnRNPC1 in the mechanism by which CVB-TD populations become established. We hypothesize that under circumstances defined by the host cell - a lack of cytoplasmic hnRNPC1 in quiescent cells - an alternative form of positive strand viral RNA synthesis initiation occurs that leads to 5' end deletions of the positive strand genome. A single specific aim is proposed to accomplish this objective: we will determine whether a range of a terminal deletions occurs in quiescent cells due to altered viral transcriptional initiation, whether that range is limited by a requirement for part of structural domain I of the 5'nontranslated region and we will examine the structure and proteins of the CVB-TD replication complex. We will determine how selective lowering of cytoplasmic hnRNPC1 affects wildtype and TD CVB replication, if hnRNPC1 fails to bind the mutated 3' terminus of CVB- TD negative strand RNA and to what extent the wildtype process of uridylylation of the enterovirus protein primer is involved in CVB3-TD initiation of positive strand RNA synthesis. Cumulatively, this work will significantly expand our knowledge of this fascinating enterovirus lifestyle, providing insight into a novel mechanism by which enteroviruses can persist and cause chronic disease in humans. PUBLIC HEALTH RELEVANCE: This study is to determine the conditions and processes for generation of persistent enterovirus infections. These infections in hearts are associated with long term effects upon heart function including debilitating conditions such as dilated cardiomyopathy and chronic myocarditis. Understanding how selection of these variant viruses occurs and how these viruses replicate will provide the basis for developing treatments and detection of these viruses in heart, neurological and pancreatic disease.

描述(申请人提供)：变异的RNA病毒在适应新环境方面非常成功。我们将在这个项目中探索这样一种新发现的适应，确定对复制效率至关重要的基因组区域的丢失如何允许肠道病毒适应不同的细胞内环境。肠道病毒被认为具有迅速溶解的特点，会导致短期感染。然而，B组柯萨奇病毒(CVB)可以删除基因组5‘末端(TD)的序列，同时保持功能，最重要的是，在感染后在心脏或细胞培养中持续较长时间的这一发现，为挑战这一传统观点提供了依据。鉴于肠道病毒RNA的5‘端参与了病毒复制的许多功能，基因组5’端多达49个核苷酸的缺失对病毒来说应该是一个可怕的事件，事实上也是如此。其中，病毒复制显著减慢，正链RNA合成受阻，导致感染细胞中病毒RNA的阳性与阴性比例接近1：1。这项建议的目的是表征hnRNPC1在CVB-TD种群建立机制中的作用。我们假设，在宿主细胞定义的情况下--静止细胞中缺乏细胞质hnRNPC1--另一种形式的正链病毒RNA合成发生，导致正链基因组的5‘端缺失。为了实现这一目标，我们提出了一个特定的目标：我们将确定在静止细胞中是否由于病毒转录起始的改变而发生一定范围的末端缺失，该范围是否受到5‘非翻译区结构域I的部分要求的限制，我们将研究CVB-TD复制复合体的结构和蛋白质。我们将确定如果hnRNPC1未能结合CVB-TD负链RNA突变的3‘端，细胞质hnRNPC1的选择性降低如何影响野生型和TD CVB复制，以及肠道病毒蛋白引物的尿苷基化野生型过程在多大程度上参与CVB3-TD启动正链RNA的合成。总而言之，这项工作将极大地扩展我们对这种迷人的肠道病毒生活方式的了解，为深入了解肠道病毒可以持续存在并导致人类慢性疾病的新机制提供洞察力。 公共卫生相关性：这项研究旨在确定持续肠道病毒感染的条件和过程。心脏中的这些感染与心脏功能的长期影响有关，包括扩张型心肌病和慢性心肌炎等衰弱状况。了解这些变异病毒的选择是如何发生的，以及这些病毒是如何复制的，将为开发心脏、神经和胰腺疾病中这些病毒的治疗和检测提供基础。