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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.

摘要先天免疫为宿主提供了应对入侵病原体的第一道防线。模式识别受体(PRRs)感知病毒和其他病原体中的病原体相关分子模式(PAMP)。 RIG-I/MDA-5是RIG-I样受体(RLR)途径中的DExD/H盒RNA解旋酶，可检测到阻断RNA病毒基因组并激活线粒体适配蛋白MAVS。DNA传感器cGAS 检测双链DNA并激活跨膜内质网适配器STING。两者都有 MAV和STING激活规范的(IKA和IKKB)，以及非规范的IKK激酶(TBK1和IKKI)，以分别激活转录因子NF-kB和IRF3。IRF3和NF-kB共同调控该基因的表达 I型干扰素(干扰素)和炎症基因，协调先天性反应并启动适应性对病原体的免疫反应。NLRP3炎症体也在炎症性疾病中发挥关键作用通过触发caspase-1介导的前-IL-1b裂解产生生物活性形式的IL-1b来进行反应推动炎症和适应性免疫的1B蛋白。NLRP3还可以诱导一种高度溶解的炎症细胞通过裂解Gasdermin-D形成质膜孔，死亡称为上睑下垂。RLR，cGAS- 刺痛和NLRP3炎症小体通路是炎症的有效诱因，必须严格调控以避免过度的炎症和组织损伤。TAX1BP1首次被鉴定为抗细胞凋亡与锌指脱泛素酶A20/TNFAIP3相互作用的蛋白质。我们之前的工作已经确立了 TAX1BP1抑制细胞因子诱导的核因子-kB活化以及RLR诱导的I型干扰素的产生和细胞凋亡。TAX1BP1作为一种选择性自噬受体，通过招募泛素化的Cargo来通过两个LC3相互作用区(LIR)发育自噬小体。然而，目前还不清楚是如何 TAX1BP1的自噬功能受到调节，如果TAX1BP1抑制其他先天免疫信号通路。在……里面初步研究我们提供了TAX1BP1被两种非正则基因磷酸化的实验证据和控制基础和病毒诱导的TAX1BP1自噬降解的典型IKK激酶分别进行了分析。利用TAX1BP1缺陷的巨噬细胞，我们证明了TAX1BP1是一种新的抑制物 CGAS-STING和NLRP3通路的表达。此外，MAVS蛋白聚集体在TAX1BP1- 缺乏细胞提示在调节先天免疫信号中有潜在的吞噬功能。这个推动这项研究的中心假设是TAX1BP1抑制RLR、cGAS-STING和NLRP3 自噬介导的清除信号蛋白聚集体的途径。我们将检验这一假设实验的具体目的如下：(1)确定TAX1BP1磷酸化在ITS中的作用自噬功能，(2)确定TAX1BP1抑制cGAS-STING途径的机制，以及 (3)探讨TAX1BP1抑制NLRP3途径的机制。完成拟议的研究将为先天免疫调节和免疫动态平衡提供新的见解。