Control of Viral Pathogenesis by Regulation of 2-5A Levels

通过调节 2-5A 水平控制病毒发病机制

• 批准号: 8476886
• 负责人: Robert H. Silverman
• 金额: $ 71.6万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8476886
• 关键词: 2-5A Synthetase; A kinase anchoring protein; Acute Hepatitis; Antigens; Antiviral Agents; Antiviral Response; Apoptosis; Blood; Cells; Chronic; Cleaved cell; Complex; Coronavirus; Development; Discontinuous Capillary; Disease; Double-Stranded RNA; Endothelial Cells; Environment; Enzymes; Family; Gatekeeping; Genes; Hepatitis; Hepatocyte; Host Defense; Human; Human Viral Hepatitis; Immune; Immune response; Infection; Interferon Type I; Interferons; Intestines; Kupffer Cells; Lead; Ligase; Liver; Liver parenchyma; Location; Mediating; Modeling; Molecular; Murine hepatitis virus; Mus; Natural Immunity; Pathogenesis; Pathology; Pathway interactions; Play; Production; Protein Biosynthesis; Proteins; RNA; Regulation; Ribonucleases; Role; Rotavirus; Signal Transduction; Small RNA; Testing; Therapeutic; Tissues; Tropism; Viral; Viral Pathogenesis; Viral Proteins; Viral hepatitis; Virus; Virus Diseases; Virus Inhibitors; Virus Replication; Wild Type Mouse; Wit; base; body system; cell type; high throughput screening; human coronavirus; inhibitor/antagonist; knock-down; macrophage; mouse model; mutant; novel; novel strategies; oligoadenylate; phosphodiesterase V; phosphoric diester hydrolase; prevent; public health relevance; response; small molecule

DESCRIPTION (provided by applicant): The ability of viruses to evade or antagonize the host type I IFN response plays an important role in viral tropism and disease pathogenesis. However, the precise cellular and molecular mechanisms by which viruses impede tissue specific host defenses leading to virus-induced pathology remain elusive. The coronavirus, mouse hepatitis virus (MHV), causes acute hepatitis in its natural host and provides a useful model for understanding virus interaction with liver cells. The MHV protein ns2 blocks the IFN-inducible and potent antiviral 2',5'-oligoadenylate (2-5A) synthetase (OAS)-RNase L pathway in macrophages and facilitates the development of hepatitis. The ns2 protein and related viral (rotavirus VP3) and mammalian (AKAP7) proteins are 2H phosphoesterases with 2',5'-phosphodiesterase (PDE) activities that degrade 2-5A, the activator of RNase L. Our long-term objective is to probe the role of viral and host 2',5'-PDEs in antiviral innate immunity and its effect on viral pathogenesis. Our overall hypothesis herein is that the OAS-RNase L pathway in macrophages is critical in protecting the host from developing viral hepatitis. Our Specific Aims are: (1) To determine if RNase L signaling in liver macrophages (Kupffer cells, KC) restricts virus from entering the liver parenchyma and inducing hepatitis, we will compare MHV replication and activation of the OAS-RNase L pathway in primary cultures of KC, liver endothelial cells and hepatocytes, generate mice with cell type specific deletions of the RNase L gene and assess the development of hepatitis using wild type and ns2 mutant MHV. (2) To determine the roles of ns2 related viral and host 2',5'-PDEs, we will study their effects on 2-5A levels, viral replication, apoptosis and IFN-¿ induction; and identify small molecule inhibitors of viral 2',5'-PDEs (ns2 and VP3) and cellular 2',5'-PDE (AKAP 7) by high throughput screening. (3) To determine and compare the "proviral" and RNase L "antagonist" activities of cellular and viral 2',5'-PDEs, we will investigate the mechanisms underlying 2',5'-PDE mediated protection to MHV by determining subcellular location of MHV replication complexes and ns2 and cellular AKAP7; generate chimeric viruses expressing different viral and cellular 2',5'-PDEs and determine their ability to antagonize RNase L and induce hepatitis. In addition, to determine effects of controlling 2-5A levels on viral pathogenesis during ongoing infections, virus-infected mice will be treated with inhibitors of 2',5'-PDEs. Our proposed studies will investigate a novel mode of regulation of the IFN antiviral response with broad implications for the control of viral infections that extend beyond hepatitis to virus mediated pathologies in other organ systems. Expected results include defining the role of KC as "gatekeeper" that prevents viruses from entering into the liver parenchyma and defining proviral and RNase L antagonist roles of diverse viral and cellular 2',5'-PDEs. It is anticipated that further understanding of the competition between virus and type I IFN signaling, particularly the OAS-RNase L pathway, will aid in the development or refinement of therapeutic strategies for human viral hepatitis and other viral diseases.

描述（由申请人证明）：病毒类型IFN反应的能力在M和疾病发病机理中起重要作用，小鼠肝炎病毒（MHV）有用的模型，用于了解与肝细胞的病毒相互作用。肝炎的病毒（轮状病毒VP3）和哺乳动物（AKAP7）蛋白是2H磷酸酯，具有2'，5'-磷酸二酯酶（PDE）的活性2-5A 2'，5'-PDE的作用在抗疾病的抗shothothothothothothothothingphothophothothothingphothothothothothothingingothothingothothingingothothingothothingsothothophothothothothothophothothothothothothothothothothothothothothothothothothothothothothothothothothothoshos一下一下一下，在抗肢体上施用了抗胸腔，这在巨噬细胞中是至关重要的。肝巨噬细胞中的RNase L信号传导（Kupffer细胞，KC）限制进入肝实质并诱导肝炎，我们将比较MHV复制和rNase L疗法N疗法N原发性的KC，肝脏中心细胞和肝类型的小鼠，并将其比较使用野生型和NS2突变体MHV评估肝炎的发展。指示； 通过高吞吐量筛选，病毒2'，5'-PDE（NS2和VP3）和细胞2，5'-PDE（AKAP 7）。研究MHV复制复合物和NS2和细胞AKAP7的2'的机制；产生表达不同病毒和细胞2'，5'-PDE的嵌合病毒在持续的感染过程中，感染病毒的小鼠将用2'，5'-PDES的抗裂素进行治疗，这些感染延伸到肝炎以外的病毒介导的病毒介导的其他器官系统中。并定义了多种病毒ND细胞2'，5'-PDE的病毒和RNase LNase。