Helicase Regulation of dsRNA Signaling and Innate Antiviral Immune Responses

dsRNA 信号传导和先天抗病毒免疫反应的解旋酶调节

• 批准号: 7994748
• 负责人: CURT M HORVATH
• 金额: $ 37.81万
• 依托单位: NORTHWESTERN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-12-15 至 2012-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7994748
• 关键词: A549; Address; Anabolism; Antiviral Agents; Antiviral Response; Baculoviruses; Biochemical; Biological; Boxing; Cell Culture Techniques; Cells; Critiques; Detection; Double-Stranded RNA; Evaluation; Exhibits; Family; Feedback; HIV; Hand; Health; Hepatitis C virus; Hepatocyte; Human; Immune response; In Vitro; Influenza; Interferon Type I; Interferons; Investigation; Knock-out; Lung Adenocarcinoma; Measles; Mediating; Mediator of activation protein; Molecular; Mumps; N-terminal; Parainfluenza; Paramyxovirus; Pathway interactions; Production; Proteins; Published Comment; Publishing; RNA; RNA Helicase; RNA Interference; RNA Viruses; Regulation; Relative (related person); Reporting; Respiratory Tract Infections; Respiratory syncytial virus; Role; Signal Pathway; Signal Transduction; Signaling Protein; Specificity; System; TLR3 gene; Tertiary Protein Structure; Therapeutic Intervention; Toll-like receptors; Viral; Viral Pathogenesis; Virus Diseases; Virus Replication; base; falls; fibrosarcoma; helicase; in vivo; inhibitor/antagonist; interest; preference; protein purification; research study; response; sensor; tool

DESCRIPTION (provided by applicant): The long term objective for this project is to understand the regulatory mechanisms and specific mediators of innate antiviral responses. A major contribution to host immune responses to virus infection is the production of and response to type I interferon (IFN). Virus infection or accumulated virus replication intermediates like double-stranded RNA (dsRNA) can trigger IFN biosynthesis in most cells irrespective of the presence of Toll-like receptor systems. Detection of cytosolic dsRNA is mediated by a family of sensor proteins that includes RIG-I, MDA5, and LGP2, three proteins that contain DEXD/H-box RNA helicase domains. RIG-I and MDA5 helicase domains are fused to an N-terminal region homologous to CARD domain proteins, and are positive signaling proteins leading to IFN biosynthesis. LGP2 lacks the CARD domain, and has been characterized as a feedback inhibitor for IFN synthesis. Despite the RNA helicase domain similarities, little is known about the specific enzymatic activities and how catalytic activity can influence the signaling. Preliminary results and published reports reveal a high degree of specificity in RNA recognition and differential requirements for enzymatic activity among the helicase proteins. Further specificity is revealed by natural inhibitors, paramyxovirus V proteins, that selectively target MDA5 and LGP2, but not RIG-I. This proposal will determine RNA target preferences and roles for enzymatic specialization that confer specificity and selectivity to helicase-mediated antiviral responses. The molecular basis for selective paramyxovirus helicase interference will be revealed and correlated with biological evaluation of the contributions of MDA5 and LGP2 to host responses. Regulatory mechanisms and cellular partners for helicase-mediated signaling will be characterized. These aims will expose specificity determinants for both positive and negative regulation of the intracellular innate antiviral response. Paramyxoviruses like measles, mumps human parainfluenza, and respiratory syncytial viruses, as well as other RNA viruses including influenza, HIV, Ebola and hepatitis C viruses are infectious threats to human health worldwide. The proposed experiments will reveal basic mechanisms of cellular antiviral responses and determine the molecular basis for both cellular and viral inhibition mechanisms. This strategy will reveal the strengths and vulnerabilities of the antiviral response and identify targets for therapeutic intervention.

描述（由申请人提供）：该项目的长期目标是了解先天抗病毒反应的调节机制和特定介质。宿主对病毒感染的免疫反应的一个主要贡献是 I 型干扰素 (IFN) 的产生和反应。无论 Toll 样受体系统是否存在，病毒感染或积累的病毒复制中间体（例如双链 RNA (dsRNA)）都可以在大多数细胞中触发 IFN 生物合成。胞质 dsRNA 的检测由传感器蛋白家族介导，其中包括 RIG-I、MDA5 和 LGP2，这三种蛋白均含有 DEXD/H-box RNA 解旋酶结构域。 RIG-I 和 MDA5 解旋酶结构域融合到与 CARD 结构域蛋白同源的 N 末端区域，并且是导致 IFN 生物合成的正信号蛋白。 LGP2 缺乏 CARD 结构域，被认为是 IFN 合成的反馈抑制剂。尽管 RNA 解旋酶结构域相似，但人们对特定酶活性以及催化活性如何影响信号传导知之甚少。初步结果和已发表的报告揭示了 RNA 识别的高度特异性以及解旋酶蛋白对酶活性的不同要求。天然抑制剂副粘病毒 V 蛋白揭示了进一步的特异性，它选择性地靶向 MDA5 和 LGP2，但不靶向 RIG-I。该提案将确定 RNA 靶标偏好和酶专业化的作用，从而赋予解旋酶介导的抗病毒反应特异性和选择性。选择性副粘病毒解旋酶干扰的分子基础将被揭示，并与 MDA5 和 LGP2 对宿主反应的贡献的生物学评估相关联。将表征解旋酶介导的信号传导的调节机制和细胞伙伴。这些目标将揭示细胞内先天抗病毒反应的正向和负向调节的特异性决定因素。麻疹、腮腺炎、人类副流感和呼吸道合胞病毒等副粘病毒，以及流感、艾滋病毒、埃博拉病毒和丙型肝炎病毒等其他 RNA 病毒，对全世界人类健康构成传染性威胁。拟议的实验将揭示细胞抗病毒反应的基本机制，并确定细胞和病毒抑制机制的分子基础。该策略将揭示抗病毒反应的优势和弱点，并确定治疗干预的目标。