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: 8634013
• 负责人: Christian Stehlik
• 金额: $ 38.63万
• 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/8634013
• 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; 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）：入侵病原体被先天免疫系统的模式识别受体（PRR）识别，作为第一道防线。在巨噬细胞中，来自核苷酸结合和富含亮氨酸重复序列（NLR）蛋白家族和黑素瘤中缺失2（AIM 2）的PRR的激活导致炎性小体形成。炎性小体是一种蛋白质平台，对炎症性半胱天冬酶的激活以及随后促炎细胞因子白细胞介素（IL）-1（IL-1）的成熟和释放至关重要。IL-18。炎性小体的组装依赖于PYRIN结构域（PYD）介导的衔接蛋白ASC向活化的PRR的募集，其然后募集胱天蛋白酶原-1。此外，Caspase-4、-5和-8也参与其中。然而，炎症小体激活的细胞溶质PRRs的分子机制，特别是，调节和终止这一过程是知之甚少。我们发现了一个由PYD组成的小蛋白家族，称为PYD-含（PYDC或POP）蛋白。我们发现PYDC通过阻断炎性小体形成所必需的PYD-PYD相互作用来抑制炎性小体活化。然而，它们在体内宿主防御和炎性疾病中的确切作用和贡献仍然未知。炎性小体对于宿主防御是必不可少的;然而，不适当的炎性小体激活也会导致过度和慢性炎症、组织破坏和日益增长的自身炎症性疾病的衰弱症状。因此，平衡的炎性小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性炎症，对于稳态是必不可少的。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性小体反应。由于小鼠缺乏PYDC蛋白，我们产生了新的小鼠模型来模拟人类进化的更复杂的炎性小体调节。我们建议确定PYDC介导的炎性小体调节和终止在所有已知的情况下的炎性小体激活：病原体感染/病原体相关的分子模式（PAMP），组织损伤/损伤相关的分子模式（DAMP）和遗传性PRR突变在巨噬细胞和体内。我们将集中于选择炎性小体激活PRR。在目标1中，我们将确定巨噬细胞中每种PYDC离体炎性小体调节和终止的分子机制，在目标2中，我们提出确定PYDC介导的体内炎性小体调节。总的来说，我们的研究旨在建立PYDC家族在感染和炎性疾病期间的特异性炎性小体调节功能，我们预计这将显著促进我们对先天免疫，宿主防御和炎性疾病的基本生物学原理以及调节这些反应的机制的理解。