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: 10374900
• 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 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10374900
• 关键词: 2019-nCoV; Adaptor Signaling Protein; Address; Advisory Committees; Aging; 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.

项目总结 先天免疫对人类健康至关重要，使细胞能够检测和对抗病原体的入侵。 线粒体是调节先天免疫的重要细胞器。 小路。线粒体和内质网之间的接触部位(线粒体/内质网接触，或 MERS)对线粒体动态平衡(如复制线粒体DNA或mtDNA)很重要， 也可作为抗病毒dsRNA反应的信号平台。然而，默斯在世界经济中的作用 对细胞质DNA的先天免疫反应的调节还不是很清楚。此外，线粒体DNA 当从线粒体释放到细胞质时，激活先天免疫途径。劳拉·纽曼博士 已经发现，Mercs刺激mtDNA的释放，以回应由 线粒体DNA损伤。尽管细胞质mtDNA增强抗病毒防御能力是众所周知的，但无论 Mercs在病毒感染过程中对mtDNA释放的调控尚不清楚。某些DNA病毒(HSV-1和EBV) 直接损伤mtDNA或抑制其复制，提示mtDNA的移除(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来测试Mercs是否中介释放 在感染过程中线粒体DNA受损。此外，RNA病毒破坏ER和MercS进行复制。释放 线粒体的线粒体DNA在感染几种RNA病毒(如流感)时发生；因此， Mercs还可能介导线粒体DNA的释放，以回应RNA病毒的感染。中心假设是 Mercs调节mtDNA的释放，协调dsRNA和DNA的先天免疫反应，以放大细胞 抗病毒防御。目的1研究Mercs在HSV-1或EBV感染过程中是否刺激线粒体DNA的释放， 以及线粒体DNA释放到胞浆中是否有利于宿主细胞或病毒。Aim#2建立在纽曼博士的基础上 初步数据表明，线粒体蛋白Mfn1增强了对细胞质DNA的先天免疫反应， 并测试Mfn1是否与感知DNA(刺痛)和dsRNA的两个先天免疫适配器形成复合体 (MAV)在默斯公司监管抗病毒防御。最后，AIM#3检查了RNA病毒(甲型流感 和SARS-CoV-2)破坏Mercs，导致mtDNA复制和释放停滞，以及这是否增强了 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，可能会提供新的治疗目标，以限制病毒感染。这项研究还将 为应聘者提供病毒学培训，并进行病毒-线粒体相互作用的研究 送到她自己的实验室。该奖项将使纽曼博士能够利用病毒学和免疫学的专业知识，通过 她的顾问委员会(O‘Shea博士和Kaech博士)以及其他职业发展机会 索尔克研究所。这将有助于她转变为一名专门研究线粒体作用的独立科学家 在先天免疫途径内，这是一个迅速扩大和重要的科学研究领域。