Regulation of cytosolic pattern recognition receptor signaling in macrophages

巨噬细胞胞质模式识别受体信号传导的调节

• 批准号: 8437829
• 负责人: Christian Stehlik
• 金额: $ 36.31万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-03-11 至 2018-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8437829
• 关键词: AIM2 gene; Acute; Adaptor Signaling Protein; Affect; Back; Bacterial Infections; Binding; Biological; Bone Marrow; Caspase; Caspase-1; Chronic; Communicable Diseases; Complex; Cytosol; Defect; Development; Disease; Equilibrium; Failure; Familial Mediterranean Fever; Family; Family member; Feedback; Francisella tularensis; Gene Transfer; Goals; Health; Homeostasis; Host Defense; Human; Immune; Immune System Diseases; Immune response; Immune system; In Vitro; Infection; Inflammation; Inflammatory; Inherited; Interleukin-1; Interleukin-18; Interleukins; Invaded; Leucine-Rich Repeat; Link; Mediating; Modeling; Molecular; Mus; Mutation; Natural Immunity; Nomenclature; Nucleotides; Pathway interactions; Patients; Pattern; Pattern recognition receptor; Positioning Attribute; Process; Production; Protein Family; Proteins; Receptor Signaling; Recruitment Activity; Regulation; Research; Role; Signal Transduction; Simulate; Small Interfering RNA; Sterility; Symptoms; Testing; Time; Tissues; Transgenic Mice; Vaccinia virus; Viral; Virus Diseases; Work; base; combat; cytokine; design; feeding; human CASP4 protein; improved; in vivo; inflammatory modulation; macrophage; marenostrin; member; mouse model; mutant; novel; novel therapeutics; pathogen; prevent; procaspase-1; public health relevance; receptor; research study; response; secretion process; tool; treatment strategy

DESCRIPTION (provided by applicant): Invading pathogens are recognized by pattern recognition receptors (PRRs) of the innate immune system as a first line of defense. Activation of PRRs from the Nucleotide-binding and leucine-rich repeat containing (NLR) protein family and Absent in melanoma 2 (AIM2) in macrophages results in inflammasome formation. Inflammasomes are protein platforms that are essential for the activation of inflammatory Caspases and subsequently for the maturation and release of the pro-inflammatory cytokines interleukin (IL)-1? and IL-18. Assembly of inflammasomes depends on PYRIN domain (PYD)-mediated recruitment of the adaptor protein ASC to activated PRRs, which then recruits pro-Caspase-1. In addition, Caspase-4, -5 and -8 participate. However, the molecular mechanism of inflammasome activation by cytosolic PRRs and in particular, regulation and termination of this process is poorly understood. We discovered a family of small proteins composed of only a PYD, called PYD-containing (PYDC or POP) proteins. We show that PYDCs function to inhibit inflammasome activation by blocking the PYD-PYD interactions essential for inflammasome formation. However, their precise role and contribution to in vivo host defense and inflammatory disease is still unknown. Inflammasomes are essential for host defense; however, inappropriate inflammasome activation also causes excessive and chronic inflammation, tissue destruction and the debilitating symptoms of the growing autoinflammatory diseases. Therefore, a balanced inflammasome response to allow pathogen clearance during acute infection, while preventing systemic inflammation through timely termination, is essential for homeostasis. We hypothesize that it is the role of the PYDC proteins to maintain this balanced inflammasome response through a negative feedback mechanism. Since PYDC proteins are lacking from mice, we generated novel mouse models to simulate the more complex inflammasome regulation evolved in humans. We propose to determine PYDC-mediated inflammasome regulation and termination during all known scenarios of inflammasome activation: pathogen infection/pathogen-associated molecular pattern (PAMP), tissue damage/damage associated molecular pattern (DAMP) and hereditary PRR mutation in macrophages and in vivo. We will focus on select inflammasome-activating PRRs. In aim 1 we will determine the molecular mechanism of inflammasome regulation and termination for each PYDC ex vivo in macrophages and in aim 2 we propose to determine PYDC-mediated inflammasome regulation in vivo. Collectively, our study is designed to establish the specific inflammasome regulatory function of the PYDC family during infection and inflammatory disease, which we expect will significantly advance our understanding of fundamental biological principles underlying innate immunity, host defense and inflammatory disease and the mechanism by which these responses are regulated.

描述（由申请人提供）：先天免疫系统的模式识别受体（PRR）识别入侵的病原体，作为第一道防线。巨噬细胞中核苷酸结合和富含亮氨酸重复序列 (NLR) 蛋白家族和黑色素瘤缺失 2 (AIM2) 中 PRR 的激活会导致炎性体形成。炎症小体是蛋白质平台，对于激活炎症性半胱天冬酶以及随后促炎细胞因子白细胞介素 (IL)-1 的成熟和释放至关重要？和IL-18。炎症小体的组装取决于 PYRIN 结构域 (PYD) 介导的接头蛋白 ASC 向激活的 PRR 的募集，然后 PRR 募集 pro-Caspase-1。此外，Caspase-4、-5和-8也参与其中。然而，人们对胞质 PRR 激活炎症小体的分子机制，特别是该过程的调节和终止知之甚少。我们发现了一个仅由 PYD 组成的小蛋白家族，称为含 PYD（PYDC 或 POP）蛋白。我们发现 PYDCs 通过阻断炎症小体形成所必需的 PYD-PYD 相互作用来抑制炎症小体激活。然而，它们对体内宿主防御和炎症疾病的确切作用和贡献仍然未知。炎症小体对于宿主防御至关重要；然而，不适当的炎症小体激活也会导致过度和慢性炎症、组织破坏以及日益严重的自身炎症性疾病的衰弱症状。因此，平衡的炎性体反应以允许在急性感染期间清除病原体，同时通过及时终止来预防全身炎症，对于体内平衡至关重要。我们推测 PYDC 蛋白的作用是通过负反馈机制维持这种平衡的炎症反应。由于小鼠缺乏 PYDC 蛋白，我们构建了新的小鼠模型来模拟人类进化出的更复杂的炎症小体调节。我们建议在所有已知的炎症小体激活情况下确定 PYDC 介导的炎症小体调节和终止：病原体感染/病原体相关分子模式（PAMP）、组织损伤/损伤相关分子模式（DAMP）以及巨噬细胞和体内的遗传性 PRR 突变。我们将重点关注选定的炎症小体激活 PRR。在目标 1 中，我们将确定巨噬细胞离体中每个 PYDC 炎症小体调节和终止的分子机制，在目标 2 中，我们建议确定体内 PYDC 介导的炎症小体调节。总的来说，我们的研究旨在建立 PYDC 家族在感染和炎症性疾病期间的特定炎症小体调节功能，我们期望这将显着增进我们对先天免疫、宿主防御和炎症性疾病的基本生物学原理以及这些机制的理解。反应受到监管。