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.

项目概要 先天免疫对于人类健康至关重要，它使细胞能够检测并抵抗病原体的入侵。 线粒体是重要的细胞器，在先天免疫的调节中发挥重要作用 途径。线粒体和内质网之间的接触位点（线粒体/内质网接触，或 MERC）对于线粒体稳态（例如线粒体 DNA 或 mtDNA 的复制）非常重要， 还可以作为针对病毒 dsRNA 的抗病毒反应的信号平台。然而，MERC 在 对细胞质 DNA 的先天免疫反应的调节尚不清楚。此外，线粒体DNA 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。尽管细胞质 mtDNA 增强抗病毒防御能力已是公认的事实，但无论是 MERC 在病毒感染期间调节 mtDNA 释放尚不清楚。某些 DNA 病毒（HSV-1 和 EBV） 直接损害 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来测试 MERC 是否介导释放 感染过程中线粒体DNA受损。此外，RNA 病毒会破坏 ER 和 MERC 进行复制。释放 来自线粒体的 mtDNA 在多种 RNA 病毒（例如流感病毒）感染期间出现；所以， MERC 还可能介导 mtDNA 释放以应对 RNA 病毒感染。中心假设是 MERC 调节 mtDNA 释放并协调 dsRNA 和 DNA 先天免疫反应以放大细胞 抗病毒防御。目标#1 检查 MERC 是否在 HSV-1 或 EBV 感染期间刺激 mtDNA 释放， 线粒体 DNA 释放到细胞质中是否对宿主细胞或病毒有益。目标 #2 建立在纽曼博士的基础上 初步数据表明线粒体蛋白 MFN1 增强对细胞质 DNA 的先天免疫反应， 并测试 MFN1 是否与两个感知 DNA (STING) 和 dsRNA 的先天免疫接头复合 (MAVS) 在 MERC 中调节抗病毒防御。最后，目标 #3 检查 RNA 病毒（甲型流感病毒）是否 和 SARS-CoV-2）会破坏 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见解 抗病毒防御，可能为限制病毒感染的新治疗靶点提供信息。这项研究还将 为候选人提供病毒学培训，并将继续进行病毒-线粒体相互作用的研究 到她自己的实验室。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： 她的顾问委员会（O’Shea 博士和 Kaech），以及额外的职业发展机会 索尔克研究所。这将帮助她转变为一名专门研究线粒体作用的独立科学家 先天免疫途径，这是一个迅速扩大且重要的科学研究领域。