The role of mitochondrial/ER contacts in the regulation of mtDNA release from mitochondria, innate immune signaling, and responses to viral infection

线粒体/内质网接触在调节线粒体 mtDNA 释放、先天免疫信号传导和病毒感染反应中的作用

• 批准号: 10192447
• 负责人: Laura Elizabeth Newman
• 金额: $ 10万
• 依托单位: SALK INSTITUTE FOR BIOLOGICAL STUDIES
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-01 至 2023-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10192447
• 关键词: 2019-nCoV; Adaptor Signaling Protein; Address; Advisory Committees; Aging; Antiviral Agents; Antiviral Response; Area; Autoimmune Diseases; Award; Bacterial Infections; Biological Models; Bromodeoxyuridine; Cells; Chronic; Co-Immunoprecipitations; Communication; Complex; Cytoplasm; Cytosol; DNA; DNA Damage; DNA Virus Infections; DNA Viruses; DNA biosynthesis; Data; Dengue; Deoxyuridine; Disease; Double-Stranded RNA; Endoplasmic Reticulum; Epstein-Barr Virus Infections; Event; Excision; Genes; Health; Herpes Simplex Infections; Herpesvirus 1; Homeostasis; Host Defense; Human; Human Herpesvirus 4; Immune; Immune response; Immune signaling; Immunology; Impairment; Infection; Inflammation; Influenza; Influenza A virus; Innate Immune Response; Institutes; Interferons; Lead; Measures; Mediating; Membrane; Microscopy; Mitochondria; Mitochondrial DNA; Mitochondrial Proteins; Natural Immunity; Nucleic Acids; Organelles; Outer Mitochondrial Membrane; Pathology; Pathway interactions; Pharmacology; Play; Property; Protein Dynamics; Proteins; Publishing; RNA Virus Infections; RNA Viruses; Regulation; Research; Role; Scientist; Signal Transduction; Simplexvirus; Site; Stimulator of Interferon Genes; Testing; Tissues; Training; Viral; Virus; Virus Diseases; Virus Replication; Work; ZIKA; age related; analog; career; career development; combat; fighting; innate immune pathways; insight; mitochondrial permeability transition pore; new therapeutic target; nuclease; pathogen; response; viral DNA; virology

PROJECT SUMMARY Innate immunity is critical for human health, allowing cells to detect and combat invasion by pathogens. Mitochondria are essential organelles that play important roles within the regulation of innate immune pathways. Contact sites between mitochondria and the endoplasmic reticulum (mitochondria/ER contacts, or MERCs) are important for mitochondrial homeostasis (such as replication of mitochondrial DNA, or mtDNA), but also act as signaling platforms for antiviral responses to viral dsRNA. However, the role of MERCs in the regulation of innate immune responses to cytoplasmic DNA is not well understood. In addition, mtDNA activates innate immune pathways when released from mitochondria into the cytoplasm. Dr. Laura Newman has found that MERCs stimulate the release of mtDNA in response to stalled mtDNA replication caused by mtDNA damage. Though it is well-established that cytoplasmic mtDNA enhances antiviral defenses, whether MERCs regulate mtDNA release during viral infection is unknown. Certain DNA viruses (HSV-1 and EBV) damage mtDNA directly or inhibit its replication, suggesting that removal of mtDNA (and its antiviral properties) may aid viral replication. This provides an ideal model system to test whether MERCs mediate release of damaged mtDNA during infection. In addition, RNA viruses disrupt the ER and MERCs to replicate. Release of mtDNA from mitochondria occurs during infection by several RNA viruses (such as influenza); therefore, MERCs may also mediate mtDNA release in response to RNA viral infection. The central hypothesis is that MERCs regulate mtDNA release and coordinate dsRNA and DNA innate immune responses to amplify cellular antiviral defenses. Aim #1 examines whether MERCs stimulate mtDNA release during HSV-1 or EBV infection, and whether mtDNA release into the cytosol benefits the host cell or virus. Aim #2 builds upon Dr. Newman’s preliminary data that the mitochondrial protein MFN1 enhances innate immune responses to cytoplasmic DNA, and tests whether MFN1 complexes with two innate immune adaptors that sense DNA (STING) and dsRNA (MAVS) at MERCs to regulate antiviral defenses. Lastly, Aim #3 examines whether RNA viruses (Influenza A and SARS-CoV-2) disrupt MERCs, causing stalled mtDNA replication and release, and whether this enhances antiviral defenses. Successful completion of any aim will provide important insights into the regulation of antiviral defenses, possibly informing new therapeutic targets to limit viral infection. This research will also provide virology training to the candidate, and research on viral-mitochondrial interactions will be carried over to her own lab. This award will enable Dr. Newman to take advantage of virology and immunology expertise via her advisory committee (Drs. O’Shea and Kaech), as well as additional career development opportunities at the Salk Institute. This will aid her transition to an independent scientist specializing in the role of mitochondria within innate immune pathways, which is a rapidly expanding and important area of scientific research.

项目摘要 先天免疫对人类健康至关重要，使细胞能够检测和抵抗病原体的入侵。 线粒体是一种重要的细胞器，在先天免疫调节中起着重要作用。 途径。线粒体和内质网之间的接触位点（线粒体/ER接触，或 MERC）对于线粒体稳态（如线粒体DNA或mtDNA的复制）是重要的， 而且还充当针对病毒dsRNA的抗病毒应答的信号平台。然而，市场区域中心在 对细胞质DNA的先天性免疫应答的调节还不清楚。此外，mtDNA 当从线粒体释放到细胞质中时激活先天免疫途径。劳拉纽曼博士 发现MERC刺激mtDNA的释放，以响应由以下原因引起的mtDNA复制停滞 线粒体DNA损伤尽管胞质mtDNA增强抗病毒防御是公认的， MERC在病毒感染过程中调节mtDNA的释放尚不清楚。某些DNA病毒（HSV-1和EBV） 直接损伤mtDNA或抑制其复制，表明去除mtDNA（及其抗病毒特性） 可能有助于病毒复制。这提供了一个理想的模型系统，以测试MERC是否介导 感染时线粒体DNA受损。此外，RNA病毒破坏ER和MERC进行复制。释放 来自线粒体的mtDNA在几种RNA病毒（如流感病毒）感染期间发生;因此， MERC也可以介导响应RNA病毒感染的mtDNA释放。核心假设是， MERC调节mtDNA释放并协调dsRNA和DNA先天免疫应答以扩增细胞免疫应答。 抗病毒防御目的#1检查在HSV-1或EBV感染期间MERC是否刺激mtDNA释放， 以及mtDNA释放到胞质溶胶中是否有益于宿主细胞或病毒。目标2建立在纽曼博士的 线粒体蛋白MFN 1增强对细胞质DNA的先天免疫应答的初步数据， 并测试了MFN 1是否与两种先天免疫接头复合， （MAVS）在MERC调节抗病毒防御。最后，目标3检查RNA病毒（甲型流感病毒）是否 和SARS-CoV-2）破坏MERC，导致mtDNA复制和释放停滞，以及这是否会增强 抗病毒防御任何目标的成功完成都将为监管提供重要的见解， 抗病毒防御，可能通知新的治疗目标，以限制病毒感染。这项研究也将 为候选人提供病毒学培训，并继续进行病毒-线粒体相互作用的研究 她自己的实验室。该奖项将使纽曼博士能够通过以下方式利用病毒学和免疫学专业知识 她的咨询委员会（O 'Shea博士和Kaech博士），以及在 索尔克研究所这将有助于她转变为一名独立的科学家，专门研究线粒体的作用。 在先天免疫途径中，这是一个迅速扩大的重要科学研究领域。