Regulation of Proinflammatory Cytokine Responses by a Caspase-8-N4BP1 Axis

Caspase-8-N4BP1 轴对促炎细胞因子反应的调节

基本信息

批准号：
10704065
负责人：
Alexander Gitlin
金额：
$ 44.25万
依托单位：
SLOAN-KETTERING INST CAN RESEARCH
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-09-13 至 2027-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10704065
关键词：
Adaptor Signaling Protein Affect Agonist Anti-Inflammatory Agents Apoptosis Apoptotic Appointment Area Autoimmunity Award Binding Proteins Biochemistry Biological Process Biology CASP8 gene CD95 Antigens Career Mobility Caspase Cell Culture Techniques Cell Death Cells Cellular Immunology Cessation of life Clinical Clinical Competence Clinical Pathology Clustered Regularly Interspaced Short Palindromic Repeats Communicable Diseases Competence Data Dedications Disease Disease Progression Endowment Evaluation Faculty Funding Gene Expression Genetic Genetic Transcription Genetically Engineered Mouse Goals Health High-Throughput Nucleotide Sequencing Human Image Immune Immune System Diseases Immunity Immunologic Deficiency Syndromes Immunologic Receptors Impairment In Vitro Inflammation Inflammatory Inflammatory Response Pathway Institution Knock-in Knowledge Laboratories Leadership Licensing Ligands Link Macrophage Malignant Neoplasms Mediating Medical Medicine Mentors Mentorship Molecular Mutation NF-kappa B Natural Immunity Nerve Degeneration Pathologic Pathology Pathway interactions Patients Peer Review Phase Phosphotransferases Physicians Positioning Attribute Postdoctoral Fellow Production Proteins Publications Regulation Research Research Personnel Research Proposals Residencies Resistance Role Rotation Scientist Series Signal Pathway Signal Transduction Source Students System T-Lymphocyte TBK1 gene TLR1 gene TLR3 gene TLR4 gene TLR7 gene TNF gene TNFSF6 gene Techniques Technology Therapeutic Intervention Toll-like receptors Training Transcript Transferable Skills United States National Institutes of Health Universities Visit Work adaptive immunity autoimmune lymphoproliferative syndrome autoinflammatory diseases career constriction cytokine expectation experience faculty support genome editing genome-wide immune activation in vivo insight instructor meetings new therapeutic target novel novel therapeutic intervention phosphoproteomics response senior faculty single cell analysis undergraduate student

项目摘要

Project Summary/Abstract Rare monogenic immune disorders have illuminated key aspects of inflammation, but many of the underlying mechanisms remain poorly understood. For example, autoimmune lymphoproliferative syndrome (ALPS), a disorder in which T cells fail to undergo apoptosis, is most often caused by genetic defects in the death receptor FAS or its ligand FASL. However, mutations in caspase-8 or its adaptor FADD – which mediate cell death downstream of FAS – cause a combination of ALPS plus severe immunodeficiency. Since immunodeficiency is not generally observed in patients with FAS or FASL mutations, I hypothesized that FADD-caspase-8 must have an apoptosis-independent function downstream of an immune receptor other than FAS. Indeed, I recently discovered that activation of multiple immune receptors elicits the caspase-8-mediated cleavage of Nedd4- binding protein 1 (N4BP1), a novel cytokine suppressor. This represents a critical point of regulation during inflammation. Notably, deletion of N4BP1 does not ordinarily affect the TRIF-dependent subset of toll-like receptors (TLRs) that activate caspase-8 (e.g., TLR3 and TLR4). However, the impaired cytokine production of caspase-8-deficient macrophages stimulated with a TLR4 agonist is restored to normal by co-deletion of N4BP1. In contrast, N4BP1 deletion leads to exorbitant cytokine responses by the TRIF-independent TLRs (e.g., TLR1/2, TLR7 and TLR9) that do not directly activate caspase-8. Thus, N4BP1 cleavage by caspase-8 inactivates the anti-inflammatory activity of intact, un-cleaved N4BP1. These findings offer a novel mechanistic explanation for immunodeficiency caused by FADD-caspase-8 mutations, whereby the inability to cleave N4BP1 results in its aberrant persistence and constriction of cytokine responses. Like TLR3 and TLR4 agonists, tumor necrosis factor (TNF) also leads to caspase-8 cleavage of N4BP1, endowing TNF with the ability to inactivate N4BP1 and thereby license cytokine production by the TRIF-independent TLRs. This latter finding highlights a key point of molecular crosstalk between the TNF and TLR systems that converges on caspase-8 cleavage of N4BP1. In the current proposal, I have linked the mechanism by which N4BP1 suppresses cytokine production to a series of proteins with both previously recognized and heretofore unknown roles in inflammation. In Aim 1, I will attempt to decipher the mechanism by which N4BP1 controls the activity of this novel kinase-dependent pathway that suppresses inflammation. In Aim 2, I will dissect how N4BP1 suppresses late phase inflammatory gene expression using genome-scale technologies. In Aim 3, I will explore the mechanisms and in vivo consequences of signal integration by the TNF-caspase-8-N4BP1 axis. Together, these aims will provide novel mechanistic insights explaining a key regulatory circuit underlying inflammation. They also will serve to launch my independent research career.

项目概要/摘要罕见的单基因免疫疾病阐明了炎症的关键方面，但许多潜在的原因例如，自身免疫性淋巴增殖综合征（ALPS）的机制仍知之甚少。 T 细胞无法凋亡的疾病通常是由死亡受体的遗传缺陷引起的 FAS 或其配体 FASL 然而，caspase-8 或其接头 FADD 的突变会介导细胞死亡。 FAS 下游 – 导致 ALPS 和严重免疫缺陷的结合，因为免疫缺陷是在具有 FAS 或 FASL 突变的患者中通常没有观察到，我认为 FADD-caspase-8 必须具有事实上，我最近发现了 FAS 以外的免疫受体下游的细胞凋亡独立功能。发现多种免疫受体的激活会引发 caspase-8 介导的 Nedd4- 裂解结合蛋白 1 (N4BP1)，一种新型细胞因子抑制因子，这代表了过程中的关键点。值得注意的是，N4BP1 的缺失通常不会影响 TRIF 依赖性的 Toll 样子集。激活 caspase-8 的受体 (TLR)（例如 TLR3 和 TLR4），但细胞因子的产生受损。用 TLR4 激动剂刺激的 caspase-8 缺陷型巨噬细胞通过 N4BP1 的共同删除而恢复正常。相反，N4BP1 缺失会导致不依赖 TRIF 的 TLR（例如 TLR1/2、 TLR7 和 TLR9) 不直接激活 caspase-8，因此，caspase-8 裂解 N4BP1 会使 caspase-8 失活。完整的、未裂解的 N4BP1 的抗炎活性为这一现象提供了新的机制解释。 FADD-caspase-8 突变引起的免疫缺陷，因此无法切割 N4BP1 导致其细胞因子反应的异常持续和收缩，如 TLR3 和 TLR4 激动剂、肿瘤坏死因子。 (TNF) 还会导致 N4BP1 的 caspase-8 裂解，赋予 TNF 灭活 N4BP1 的能力，后一发现强调了 TRIF 独立 TLR 产生细胞因子的许可。 TNF 和 TLR 系统之间的分子串扰集中在 N4BP1 的 caspase-8 裂解上。目前的提案中，我将 N4BP1 抑制细胞因子产生的机制与一系列在目标 1 中，我将尝试研究在炎症中具有先前已知和未知作用的蛋白质。破译 N4BP1 控制这种新型激酶依赖性途径活性的机制在目标 2 中，我将剖析 N4BP1 如何抑制晚期炎症基因。在目标 3 中，我将探讨其机制和体内后果。通过 TNF-caspase-8-N4BP1 轴进行信号整合，这些目标将提供新的机制。解释炎症背后的关键调节回路的见解它们也将有助于启动我的研究。独立的研究生涯。