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 先天免疫对于人类健康至关重要，允许细胞检测并打击病原体的侵袭。 线粒体是在先天免疫调节中起重要作用的重要细胞器 途径。线粒体和内质网之间的接触位点（线粒体/ER接触或 MERCS）对于线粒体稳态（例如线粒体DNA或mtDNA的复制）很重要， 但也充当对病毒DSRNA抗病毒反应的信号平台。但是，Mercs在 对胞质DNA的先天免疫反应的调节尚不清楚。另外，mtDNA 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 发现Mercs刺激MTDNA的释放，以响应于停滞的mtDNA复制。 mtDNA损坏。尽管良好的是细胞质mtDNA增强了抗病毒防御能力，但是否是否 Mercs调节病毒感染期间mtDNA释放尚不清楚。某些DNA病毒（HSV-1和EBV） 直接损坏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，用于测试MERC是否介导 感染过程中受损的mtDNA。另外，RNA病毒破坏了ER和MERC的复制。释放 线粒体中的mtDNA发生在几种RNA病毒（例如造成薄膜）感染期间。所以， Mercs还可以响应RNA病毒感染而介导mtDNA释放。中心假设是 MERCS调节mtDNA释放并坐标DSRNA和DNA先天免疫回报以扩增细胞 抗病毒防御。 AIM＃1考试Mercs是在HSV-1期间刺激mtDNA释放还是EBV感染， MTDNA是否释放到细胞质中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MFN1的初步数据增强了对细胞质DNA的先天免疫反应， 并测试MFN1是否具有两个先天免疫适配器，可以感知DNA（sting）和dsRNA （MAV）在Mercs中调节抗病毒防御。最后，AIM＃3检查了RNA病毒是否（流感）是否 和SARS-COV-2）破坏Mercs，导致杂乱的mtDNA复制和释放，以及这是否增强 抗病毒防御。成功完成任何目标将为监管的重要见解 抗病毒防御，可能告知新的治疗靶标，以限制病毒感染。这项研究也将 向候选人提供病毒学培训，并将对病毒性相互作用进行研究 到她自己的实验室。该奖项将使纽曼博士通过 她的咨询委员会（O'Shea和Kaech博士），以及 萨尔克学院。这将有助于她过渡到专门从事线粒体角色的独立科学家 在先天的免疫病中，这是科学研究的快速扩展和重要领域。