Negative regulation of innate immune signaling pathways by the selective autophagy receptor TAX1BP1

选择性自噬受体 TAX1BP1 对先天免疫信号通路的负调节

基本信息

批准号：
10622514
负责人：
EDWARD W HARHAJ
金额：
$ 62.73万
依托单位：
PENNSYLVANIA STATE UNIV HERSHEY MED CTR
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-06-01 至 2026-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10622514
关键词：
Acute Adaptor Signaling Protein Agonist Amyotrophic Lateral Sclerosis Apoptosis Apoptotic Automobile Driving Autophagocytosis Autophagosome CASP1 gene CRISPR/Cas technology Cell Death Cell membrane Cells DNA DNA Viruses Data Dinucleoside Phosphates Double-Stranded RNA Endoplasmic Reticulum Gene Expression Genes Goals Golgi Apparatus Herpesvirus 1 Homeostasis Host Defense Huntington Disease IRF3 gene Immune Immune response Immune signaling Inflammasome Inflammation Inflammatory Inflammatory Response Interferon Type I Interferon alpha Interferon-beta Invaded Investigation Knock-out Knockout Mice Lytic Macrophage Mass Spectrum Analysis Mediating Membrane Mitochondria Modeling Molecular Mus NF-kappa B Natural Immunity Pathogenicity Pathway interactions Pattern Pattern recognition receptor Periodicity Peritoneal Phosphorylation Phosphorylation Site Phosphotransferases Play Principal Investigator Production Proteins RNA Helicase RNA Viruses Reagent Receptor Signaling Regulation Reporting Research Personnel Role Signal Pathway Signal Transduction Signaling Protein Specificity Stimulator of Interferon Genes TBK1 gene Testing Tissues Transcriptional Activation Viral Genome Virus Work Zinc Fingers adaptive immune response adaptive immunity cell type cytokine ds-DNA genomic RNA immunoregulation in vivo inhibitor innate immune pathways insight mutant novel pathogen pathogenic microbe prevent protein TDP-43 protein aggregation receptor reconstitution recruit response sensor tool transcription factor ubiquitin isopeptidase viral genomics virology

项目摘要

ABSTRACT Innate immunity provides the first line of host defense in response to invading pathogens. Pattern recognition receptors (PRRs) sense pathogen-associated molecular patterns (PAMPs) in viruses and other pathogens. RIG-I/MDA-5 are DExD/H box RNA helicases in the RIG-I-like receptor (RLR) pathway that detect double stranded RNA viral genomes and activate the mitochondrial adaptor protein MAVS. The DNA sensor cGAS detects double stranded DNA and activates STING, a transmembrane endoplasmic reticulum adaptor. Both MAVS and STING activate canonical (IKKa and IKKb), and noncanonical IKK kinases (TBK1 and IKKi) to activate transcription factors NF-kB and IRF3 respectively. Together, IRF3 and NF-kB regulate the expression of type I interferon (IFN) and inflammatory genes that coordinate the innate response and initiate the adaptive immune response against pathogens. The NLRP3 inflammasome also plays a critical role in inflammatory responses by triggering caspase-1-mediated pro-IL-1b cleavage to yield the biologically active form of IL- 1b that drives inflammation and adaptive immunity. NLRP3 also induces a highly lytic form of inflammatory cell death termed pyroptosis via cleavage of gasdermin-D to form plasma membrane pores. The RLR, cGAS- STING and NLRP3 inflammasome pathways are potent inducers of inflammation that must be tightly regulated to avert overexuberant inflammation and tissue damage. TAX1BP1 was first identified as an anti-apoptotic protein that interacts with the zinc finger deubiquitinase A20/TNFAIP3. Our previous work has established that TAX1BP1 restricts cytokine-induced NF-kB activation as well as RLR-induced type I IFN production and apoptosis. TAX1BP1 functions as a selective autophagy receptor by recruiting ubiquitinated cargo to developing autophagosomes via two LC3 interaction regions (LIRs). However, it remains unclear how TAX1BP1 autophagy function is regulated and if TAX1BP1 inhibits other innate immune signaling pathways. In preliminary studies we provide experimental evidence that TAX1BP1 is phosphorylated by both noncanonical and canonical IKK kinases which controls both basal and virus-induced TAX1BP1 autophagic degradation respectively. Using TAX1BP1-deficient macrophages we have demonstrated that TAX1BP1 is a novel inhibitor of both cGAS-STING and NLRP3 pathways. Furthermore, MAVS protein aggregates accumulate in TAX1BP1- deficient cells suggesting a potential aggrephagy function in the regulation of innate immune signaling. The central hypothesis driving the proposed investigations is that TAX1BP1 inhibits RLR, cGAS-STING and NLRP3 pathways by autophagy-mediated clearance of signaling protein aggregates. We will test this hypothesis experimentally with the following Specific Aims: (1) determine the role of TAX1BP1 phosphorylation in its autophagy function, (2) determine the mechanisms of TAX1BP1 inhibition of the cGAS-STING pathway, and (3) determine the mechanisms of TAX1BP1 inhibition of the NLRP3 pathway. Completion of the proposed studies will provide new insights into innate immune regulation and immune homeostasis.

抽象的先天免疫提供了宿主防御的第一线，以应对入侵的病原体。模式识别受体（PRR）在病毒和其他病原体中感知病原体相关的分子模式（PAMP）。 RIG-I/MDA-5是DEXD/H BOX RNA HELICases中的RIG-I样受体（RLR）途径，可检测双重的途径滞留的RNA病毒基因组并激活线粒体衔接蛋白MAV。 DNA传感器CGA 检测双链DNA并激活STING，这是一种跨膜内质网适配器。两个都 Mavs和Sting激活的规范（IKKA和IKKB），以及非规范的IKK激酶（TBK1和IKKI）分别激活转录因子NF-KB和IRF3。 IRF3和NF-KB一起调节表达 I型干扰素（IFN）和炎症基因，以协调先天反应并启动适应性对病原体的免疫反应。 NLRP3炎性体在炎症中也起着至关重要的作用通过触发caspase-1介导的pro-IL-1B裂解来产生IL-的生物活性形式的反应 1B驱动炎症和适应性免疫。 NLRP3还诱导了炎症细胞的高溶解形式死亡称为通过裂解加油敏-d形成质膜孔的凋亡。 RLR，CGAS- STING和NLRP3炎性途径是必须严格调节的炎症的有效诱导者避免过度调查炎症和组织损伤。税务1BP1首先被确定为抗凋亡与锌指去泛素酶A20/TNFAIP3相互作用的蛋白质。我们以前的工作已经确定税务1BP1限制了细胞因子诱导的NF-KB激活以及RLR诱导的I型IFN产生和凋亡。税务1BP1通过招募泛素化货物来充当选择性自噬受体通过两个LC3相互作用区域（LIRS）开发自噬体。但是，尚不清楚如何税务1BP1自噬功能受到调节，如果税务1BP1抑制其他先天免疫信号通路。在初步研究我们提供了实验证据，表明税务1bp1均被两种非规范性磷酸化以及控制基底和病毒诱导的税务1BP1自噬降解的规范IKK激酶分别。使用税务1BP1缺乏巨噬细胞，我们已经证明了税务1BP1是一种新型抑制剂 CGAS-sting和NLRP3途径。此外，MAVS蛋白聚集物在税务1bp1-中积累缺乏细胞表明在调节先天免疫信号传导的调节中具有潜在的杂色功能。这驱动拟议调查的中央假设是税务1BP1抑制RLR，CGAS-STING和NLRP3 自噬介导的信号蛋白聚集体的清除途径。我们将检验这个假设实验以下特定目的：（1）确定税务1bp1磷酸化在其中的作用自噬函数，（2）确定CGAS刺激途径税务1BP1的机制，并确定（3）确定NLRP3途径的税务1BP1抑制的机制。拟议的完成研究将为先天免疫调节和免疫稳态提供新的见解。