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

• 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
• 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

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.

项目摘要/摘要 罕见的单基因免疫疾病具有炎症的关键方面，但许多基础 机制仍然很少理解。例如，自身免疫性淋巴增生综合征（ALP），A T细胞无法发生凋亡的疾病，最常见于死亡接收器中的遗传缺陷引起 FAS或其配体FASL。但是，caspase-8或其适配器FADD中的突变 - 介导细胞死亡 FAS的下游 - 导致阿尔卑斯山和严重的免疫缺陷的组合。由于免疫缺陷是 在FAS或FASL突变的患者中，通常不观察到，我假设FADD-Caspase-8必须具有 除了FAS以外的免疫受体下游的凋亡非依赖性功能。确实，我最近 发现多种免疫接收器的激活引起了caspase-8介导的NEDD4-- 结合蛋白1（N4BP1），一种新型的细胞因子抑制剂。这代表了调节期间的关键点 炎。值得注意的是，N4BP1的缺失并不会影响类似TOLL的TRIF依赖性子集 激活caspase-8（例如TLR3和TLR4）的受体（TLR）。但是，细胞因子产生的受损 用TLR4激动剂刺激的caspase-8缺陷巨噬细胞通过N4BP1的共删除恢复到正常状态。 相反，N4BP1缺失导致非依赖性TLR的过高细胞因子反应（例如TLR1/2， 不直接激活caspase-8的TLR7和TLR9）。那就是caspase-8裂解N4BP1使 完整，未切换的N4BP1的抗炎活性。这些发现为 由FADD-Caspase-8突变引起的免疫缺陷，从而无法清除N4BP1导致其 细胞因子反应的异常持久性和收缩。像TLR3和TLR4激动剂一样，肿瘤坏死因子 （TNF）还导致N4BP1的caspase-8裂解，使TNF具有失活N4BP1和 因此，独立于TRIF的TLR的许可细胞因子生产。后来发现这突出了一个关键点 TNF和TLR系统之间的分子串扰在N4BP1的caspase-8裂解上收敛。在 当前的提案，我已将N4BP1抑制细胞因子产生的机制联系起来 具有先前认可的蛋白质和迄今为止未知在炎症中的作用。在AIM 1中，我会尝试 解释了N4BP1控制这种新型激酶依赖性途径的活性的机制 抑制注射。在AIM 2中，我将剖析N4BP1如何抑制后期炎症基因 使用基因组规模技术表达。在AIM 3中，我将探索机制和体内后果 TNF-Caspase-8-N4BP1轴的信号积分。这些目标在一起将提供新颖的机械 洞察力解释了炎症基础的关键调节电路。他们还将发起我的 独立研究职业。