Innate immune signal transduction specificity in inflammatory disease

炎症性疾病中的先天免疫信号转导特异性

• 批准号: 8126597
• 负责人: Derek W Abbott
• 金额: $ 7.14万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8126597
• 关键词: Applications Grants; Asthma; Atherosclerosis; Bacteria; Biochemical; Cardiovascular system; Crohn' s disease; Cytokine Activation; Data; Disease; Down-Regulation; Elderly; Exposure to; Failure; Functional disorder; Genes; Genetic; Gram-Negative Bacteria; Grant; Human; Immune; Immune response; Immune system; Infant; Inflammatory; Inflammatory Bowel Diseases; Inflammatory Response; Intervention; Lead; Link; Lysine; MAP Kinase Signaling Pathways; MAPK14 gene; Morbidity - disease rate; Multiple Sclerosis; Organism; Pathology; Pathway interactions; Pharmacologic Substance; Phosphorylation; Phosphorylation Site; Polyubiquitination; Population; Post-Translational Protein Processing; Process; Proteins; Receptor Signaling; Regulation; Role; Sarcoidosis; Scaffolding Protein; Serine; Signal Pathway; Signal Transduction; Site; Specificity; Syndrome; System; Toll-like receptors; Ubiquitination; Vascular Diseases; Virus; Work; cytokine; design; early onset; extracellular; fungus; immune activation; insight; mortality; novel; pathogen; public health relevance; response

DESCRIPTION (provided by applicant): The innate immune system recognizes and responds to pathogenic organisms. In doing so, this system is responsible for initiating a cytokine response designed to tailor the adaptive immune system to eradicate the offending organism. This process must be tightly regulated as too much activity can lead to inflammatory disease. Because inflammatory diseases are characterized by prolonged innate immune activation and cytokine release, the mechanisms controlling downregulation of the innate immune response are paramount in limiting inflammatory pathology. This grant application aims to study the mechanisms of this downregulation by focusing on the signal transduction mechanisms of NOD2 protein (CARD15 gene) and on NOD2's role in initiating and maintaining the cytokine response. The NOD2 protein is responsible for a number of inflammatory disorders including Blau Syndrome (a familial granulomatosis disease), a subset of Early Onset Sarcoidosis and for 15-20% of genetic Crohn's Disease. NOD2 is activated in response to intracellular exposure to both gram-positive and gram-negative bacteria after which it helps to coordinate NF-?B activation and cytokine release through the lysine-63 (K63)-linked polyubiquitination of a novel site (K285) on the IKK scaffolding protein NEMO. We have recently extended this finding to show that the major extracellular innate immune signaling receptors, the Toll-like Receptors (TLRs), also require K285 NEMO ubiquitination to properly signal through NF-?B. This work suggests that regulation of the post-translational modifications on the IKK scaffolding protein, NEMO, helps to coordinate cross-talk between intracellular and extracellular innate immune pathways and also helps to regulate the identity, the amount and the duration of cytokines that are released. These findings also suggest that for NF-?B signaling, multiple innate immune signaling pathways converge on NEMO and that the post-translational modifications on NEMO serve as a rheostat to control NF-?B activity. As such, these post-translational modifications may also be targets for molecules aimed at downregulating the NF-?B response activated by NOD2 and other innate immune signaling pathways. The central hypothesis of this grant is that downregulation of NOD2 and TLR-stimulated NF-?B activation is paramount in avoiding inflammatory pathology. Failure to properly downregulate the NF-?B response and coordinate between alternative (MAP kinase) signaling pathways may underlie the pathophysiology of inflammatory disorders. Study of these pathways of downregulation could lead both to novel insight regarding the pathophysiology of these diseases and to novel druggable target to help treat these diseases. To begin to tackle this important problem, we have generated significant preliminary data. We have identified a novel innate immune-induced phosphorylation site on NEMO that controls NEMO ubiquitination and therefore, controls ultimate NF-?B activation. We have also identified a signaling pathway operating through an unexpected MAP3K which inhibits NEMO ubiquitination and shifts innate immune signaling from NF-?B activity toward p38 activity. The Specific Aims of this grant application aim to determine the biochemical mechanisms by which innate immune-induced NF-?B activity can be downregulated, to determine the function of MEKK4 in dictating signal specificity downstream of innate immune system activation and to determine the role of these signaling pathways in the pathophysiology of inflammatory disease. Public Health Relevance: As humans, we are constantly exposed to bacteria, fungi and viruses, and we must respond to these pathogens so that we do not become infected. After responding to these pathogens, if our immune systems do not deactivate, we develop inflammatory disorders such as asthma, inflammatory bowel disease, multiple sclerosis and atherosclerosis (heart and vascular disease). Inflammatory diseases such as these are a significant cause of morbidity and mortality across a wide range of populations (infants to elderly). Due to the importance of downregulating the inflammatory response, our bodies have developed sophisticated mechanisms to dampen the inflammatory response. This grant application aims to study the mechanisms that dampen this inflammatory response and the mechanisms by which this dampening is faulty in inflammatory disease. This work aims to help determine the causes of inflammatory disease and aims to identify novel targets for pharmaceutical intervention in these debilitating disorders.

描述（由申请人提供）：先天免疫系统识别并响应病原微生物。在这样做的时候，这个系统负责启动细胞因子反应，旨在调整适应性免疫系统，以消除冒犯生物体。这个过程必须严格调节，因为过多的活动可能导致炎症性疾病。由于炎性疾病的特征在于延长的先天免疫激活和细胞因子释放，因此控制先天免疫应答下调的机制在限制炎性病理学中是至关重要的。该基金申请旨在通过关注NOD 2蛋白（CARD 15基因）的信号转导机制以及NOD 2在启动和维持细胞因子应答中的作用来研究这种下调的机制。NOD 2蛋白导致许多炎性疾病，包括Blau综合征（一种家族性肉芽肿病），早发性结节病的一个子集和15-20%的遗传性克罗恩病。NOD 2被激活，以响应细胞内暴露于革兰氏阳性和革兰氏阴性细菌后，它有助于协调NF-？通过IKK支架蛋白NEMO上新位点（K285）的赖氨酸-63（K63）-连接的多聚泛素化，B激活和细胞因子释放。我们最近扩展了这一发现表明，主要的细胞外先天性免疫信号受体，Toll样受体（TLR），也需要K285 NEMO泛素化，通过NF-？B。这项工作表明，IKK支架蛋白NEMO上的翻译后修饰的调节有助于协调细胞内和细胞外先天免疫途径之间的串扰，也有助于调节释放的细胞因子的身份、数量和持续时间。这些研究结果还表明，NF-？B信号，多种先天免疫信号通路汇聚在NEMO上，NEMO上的翻译后修饰充当变阻器来控制NF-？B活性。因此，这些翻译后修饰也可能是目标分子的目的是下调NF-？由NOD 2和其他先天免疫信号传导途径激活的B应答。这项研究的中心假设是NOD 2和TLR刺激的NF-？B活化在避免炎症病理学方面是至关重要的。不能正确下调NF-？B反应和交替（MAP激酶）信号通路之间的协调可能是炎症性疾病的病理生理学基础。对这些下调途径的研究可能会导致对这些疾病的病理生理学的新见解，以及帮助治疗这些疾病的新药物靶点。为了开始解决这一重要问题，我们已经获得了重要的初步数据。我们已经确定了一个新的先天免疫诱导的磷酸化网站NEMO控制NEMO泛素化，因此，控制最终NF-？B激活。我们还确定了一个信号通路，通过一个意想不到的MAP 3 K，抑制NEMO泛素化和转移先天免疫信号从NF-？B活性对p38活性。本申请的具体目的是确定先天免疫诱导NF-？可以下调B活性，以确定MEKK 4在决定先天免疫系统激活下游的信号特异性中的功能，并确定这些信号传导途径在炎性疾病的病理生理学中的作用。 公共卫生相关性：作为人类，我们不断暴露于细菌，真菌和病毒，我们必须对这些病原体做出反应，这样我们就不会被感染。在对这些病原体作出反应后，如果我们的免疫系统没有失活，我们就会患上炎症性疾病，如哮喘、炎症性肠病、多发性硬化症和动脉粥样硬化（心脏和血管疾病）。诸如这些的炎性疾病是广泛人群（婴儿到老年人）的发病率和死亡率的重要原因。由于下调炎症反应的重要性，我们的身体已经发展出复杂的机制来抑制炎症反应。这项拨款申请旨在研究抑制这种炎症反应的机制，以及这种抑制在炎症性疾病中存在缺陷的机制。这项工作旨在帮助确定炎症性疾病的原因，并旨在确定药物干预这些衰弱性疾病的新靶点。