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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：
10414107
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/10414107
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 Interferons Invaded Investigation Knock-out Knockout Mice Lytic Mass Spectrum Analysis Mediating 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 activating transcription factor adaptive immune response adaptive immunity base cell type cytokine ds-DNA genomic RNA immunoregulation in vivo inhibitor innate immune pathways insight macrophage mutant novel pathogen pathogenic microbe prevent protein TDP-43 protein aggregation receptor reconstitution recruit response sensor tool transcription factor 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.

摘要先天免疫提供了宿主防御入侵病原体的第一道防线。模式识别受体（PRR）感测病毒和其它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，其检测双链RNA解旋酶。链RNA病毒基因组和激活线粒体衔接蛋白MAVS。DNA传感器cGAS 检测双链DNA并激活跨膜内质网接头STING。两 MAVS和STING激活经典（IKKa和IKKb）和非经典IKK激酶（TBK 1和IKKi），分别激活转录因子NF-κ B和IRF 3。IRF 3和NF-kB共同调控了 I型干扰素（IFN）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。NLRP 3炎性体也在炎症反应中起关键作用。通过触发caspase-1介导的pro-IL-1b裂解产生生物活性形式的IL-1b的反应 1b驱动炎症和适应性免疫。NLRP 3还诱导高度溶解形式的炎性细胞通过gasdermin-D裂解形成质膜孔而死亡，称为焦亡。RLR，CGAS- STING和NLRP 3炎性体通路是必须严格调控的炎症的有效诱导剂以避免过度炎症和组织损伤。TAX 1BP 1首次被鉴定为抗细胞凋亡蛋白。与锌指去泛素化酶A20/TNFAIP 3相互作用的蛋白质。我们以前的工作已经确定， TAX 1BP 1限制马槟榔诱导的NF-kB活化以及TLR诱导的I型IFN产生，凋亡TAX 1BP 1作为一种选择性自噬受体，通过募集泛素化的货物，通过两个LC 3相互作用区域（LIR）形成自噬体。然而，目前尚不清楚如何 TAX 1BP 1自噬功能受到调节，如果TAX 1BP 1抑制其他先天免疫信号通路。在我们的初步研究提供了实验证据，TAX 1BP 1是磷酸化的非典型的，和控制基础和病毒诱导的TAX 1BP 1自噬降解的经典IKK激酶分别使用TAX 1BP 1缺陷的巨噬细胞，我们已经证明TAX 1BP 1是一种新的抑制剂， cGAS-STING和NLRP 3通路的信号传导。此外，MAVS蛋白聚集体在TAX 1BP 1中积累。缺陷的细胞表明在先天免疫信号传导的调节中潜在的聚集吞噬功能。的推动拟议研究的中心假设是TAX 1BP 1抑制RLR、cGAS-STING和NLRP 3 通过自噬介导的信号蛋白聚集体的清除途径。我们将检验这一假设（1）确定TAX 1BP 1磷酸化在TAX 1BP 1磷酸化过程中的作用，自噬功能，（2）确定TAX 1BP 1抑制cGAS-STING途径的机制，和 (3)确定TAX 1BP 1抑制NLRP 3通路的机制。完成建议研究将为先天免疫调节和免疫稳态提供新的见解。