Inflammasome function and SJIA

炎症小体功能和 SJIA

基本信息

批准号：
8285388
负责人：
Elizabeth D Mellins
金额：
$ 21.33万
依托单位：
STANFORD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-08-01 至 2014-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8285388
关键词：
Accounting Adaptor Signaling Protein Affect Age Apoptosis Arthritis Biochemical Biology Blood C-reactive protein Candidate Disease Gene Caspase-1 Cell Aging Cell Death Cells Child Chronic Chronic Childhood Arthritis Cleaved cell Clinical Complex Complication Data Defect Disease Employee Strikes Evaluation Event Exanthema Fever Genes Genetic Genetic Screening Goals Hereditary Disease Immune Inflammation Inflammation Mediators Inflammatory Institutes Integration Host Factors Interleukin-1 Interleukin-18 Knowledge Laboratories Lead Light Macrophage Activation Measures Mediating Molecular Multiprotein Complexes Mutation Normal Cell Pathogenesis Pathway interactions Patients Peptide Signal Sequences Pericarditis Play Pleurisy Prevention approach Process Production Proteins Purinoceptor Regulation Relapse Resolution Rheumatoid Arthritis Role Small Interfering RNA Staging Stimulus Subcellular structure Syndrome Testing Work anakinra arthritis therapy base cell age cytokine driving force follow-up genome-wide inhibitor/antagonist innovation interest macrophage monocyte mortality novel porin response secretion process

项目摘要

DESCRIPTION (provided by applicant): Systemic juvenile idiopathic arthritis (SJIA) is a rheumatic condition characterized by arthritis, quotidian fever, evanescent rash, and sometimes other types of systemic inflammation. SJIA is currently thought to be a multigenic, autoinflammatory disease, but the molecular details of its pathogenesis are still unknown. A striking feature of SJIA is its association with macrophage activation syndrome (MAS), a complication that can be fatal. This clinical aspect, together with data from immunophenotypic studies of SJIA, points to the monocyte lineage as being important in disease pathogenesis. Activated monocytes express components of the inflammasome, a multiprotein complex that senses infectious or noxious stimuli and activates caspase-1, leading to maturation and secretion of IL-1beta and IL-18 and sometimes to host cell death IL-1beta and IL-18 have been implicated in SJIA. Based on our preliminary data, we hypothesize that monocytes from SJIA patients harbor a defect in the inflammasome pathway. The objective of this R21 proposal is to discover host pathways and genes that influence IL- 1beta maturation and release by monocytes and to test these as candidate disease associated factors. In Aim 1, we will take a candidate approach to characterize possible defects in SJIA monocytes by measuring known molecular events related to IL-1beta secretion in cells from SJIA patients compared to cells from age-matched immunologically normal children. Specifically, we will measure cytokine release, activation of caspase-1, caspase-1 regulated cell death, levels of expression of Rab 39a, the purinergic receptor P2X7R, and the pore-forming protein, pannexin-1. Findings will be followed up with sequencing of associated candidate genes in 35 SJIA patients. In Aim 2, we will take a less biased approach and conduct a forward genetic screen to identify host factors that influence IL-1beta secretion in normal cells. This screen will likely provide additional candidate factors potentially affecting IL-1beta biology in SJIA. Our results will delineate molecular components regulating IL-1 processing and secretion and, ultimately, could result in new and innovative approaches to the prevention and treatment of SJIA and other autoinflammatory diseases. PUBLIC HEALTH RELEVANCE: Systemic juvenile idiopathic arthritis (sJIA) is a chronic rheumatic condition in children characterized by remitting fever, transient rash, and relapsing arthritis. Although sJIA represents only 10-20% of the total cases of chronic inflammatory arthritis in children (JIA), it accounts for more than 2/3 of JIA mortality, due to complications o this disease and its treatment. The cause of sJIA is unknown, but recent evidence strongly suggests that a driving force is excessive activity of an endogenous inflammatory mediator called IL-1. This conclusion is based on the efficacy of anti-IL-1 therapy in a large subset of sJI patients, especially if this treatment approach is instituted early. We are interested in elucidatig the basis of uncontrolled IL-1 activity in sJIA. The Mellins laboratory has been studying the immune cells found in the blood of children with sJIA and has found evidence for abnormal regulation of IL-1 secretion in these cells. The Monack laboratory has been studying the basic cellular mechanisms that control IL-1 secretion in immune cells. While certain aspects of IL-1 control have been uncovered, such as the importance of a subcellular structure known as the "inflammasome," it is clear that more molecular events remain to be discovered. Using modern genetic and biochemical approaches, our laboratories will work to identify the molecular steps involved in production and secretion of active IL-1 from immune cells. We then will go on to determine at which step(s) the immune cells from sJIA patients are abnormal. This project will contribute important new knowledge on the fundamental processes involved in inflammation and will shed light on the mechanism of disease in a chronic, sometimes fatal illness of children, sJIA. The project also has the potential to identify approaches to treatments for sJIA and other inflammatory diseases where IL-1 plays a pathogenic role.

描述（由申请人提供）：全身少年特发性关节炎（SJIA）是一种风湿性疾病，其特征是关节炎，quotidian发烧，evan灭疹，有时以及其他类型的全身性炎症。目前，SJIA被认为是一种多基因自身炎性疾病，但其发病机理的分子细节仍然未知。 SJIA的一个惊人特征是它与巨噬细胞激活综合征（MAS）的关联，这可能是致命的。这一临床方面以及来自SJIA的免疫表型研究的数据表明，单核细胞谱系在疾病发病机理中很重要。活化的单核细胞表达炎性体的成分，炎症体是一种多动蛋白复合物，感知感染性或有害刺激并激活caspase-1，从而导致IL-1Beta和IL-18的成熟和分泌，有时甚至导致宿主细胞死亡IL-1Beta和IL-18。根据我们的初步数据，我们假设来自SJIA患者的单核细胞具有炎性途径中的缺陷。该R21提案的目的是发现影响IL-1Beta成熟并通过单核细胞释放的宿主途径和基因，并将其作为候选疾病相关的因素进行测试。在AIM 1中，我们将采用一种候选方法来表征SJIA单核细胞中可能的缺陷，通过测量与年龄匹配的免疫学正常儿童的细胞相比，SJIA患者细胞中与IL-1BETA分泌有关的已知分子事件。具体而言，我们将测量细胞因子释放，caspase-1的激活，caspase-1调节细胞死亡，RAB 39a的表达水平，嘌呤能受体P2X7R和孔形成蛋白Pannexin-1。在35名SJIA患者中，将通过对相关候选基因进行测序后跟踪发现。在AIM 2中，我们将采用较不偏见的方法，并进行正向遗传筛选，以识别影响正常细胞中IL-1BETA分泌的宿主因素。该屏幕可能会提供可能影响SJIA IL-1Beta生物学的其他候选因素。我们的结果将描述调节IL-1处理和分泌的分子成分，最终可能导致对SJIA和其他自发疾病的预防和治疗的新的和创新的方法。公共卫生相关性：全身少年特发性关节炎（SJIA）是一种慢性风湿病，其特征是恢复发烧，短暂性皮疹和复发性关节炎。尽管SJIA仅占儿童慢性炎性关节炎总病例（JIA）的10-20％，但由于这种疾病及其治疗的并发症，其占JIA死亡率的2/3以上。 SJIA的原因尚不清楚，但最近的证据表明，驱动力是内源性炎症介质的过度活性，称为IL-1。该结论基于抗IL-1治疗在大量SJI患者中的功效，尤其是在早期提出这种治疗方法的情况下。我们对Elucidatig感兴趣的是SJIA中不受控制的IL-1活性的基础。 Mellins实验室一直在研究SJIA儿童血液中发现的免疫细胞，并发现了这些细胞中IL-1分泌异常调节的证据。 Monack实验室一直在研究控制免疫细胞中IL-1分泌的基本细胞机制。尽管已经发现了IL-1控制的某些方面，例如称为“炎症体”的亚细胞结构的重要性，但很明显，更多的分子事件仍有待发现。使用现代的遗传和生化方法，我们的实验室将努力确定与免疫细胞中活性IL-1分泌有关的分子步骤。然后，我们将继续确定SJIA患者的免疫细胞在哪个步骤中是异常的。该项目将在涉及炎症的基本过程中贡献重要的新知识，并阐明儿童慢性，有时是致命的疾病SJIA的疾病机制。该项目还具有鉴定IL-1起致病作用的SJIA和其他炎症性疾病的治疗方法。