Mechanism of Neutrophil Activation

中性粒细胞激活机制

• 批准号: 8621979
• 负责人: Kenneth R MCLEISH
• 金额: --
• 依托单位: LOUISVILLE VA MEDICAL MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-10-01 至 2016-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8621979
• 关键词: Acute; Acute Lung Injury; Address; Adult Respiratory Distress Syndrome; Affect; Aging; Animal Model; Antineutrophil Cytoplasmic Antibodies; Arteriosclerotic Cardiovascular Disease; Atherosclerosis; Bacteria; Biochemical Genetics; Biology; Cell membrane; Chemicals; Chronic; Cytoplasmic Granules; Data; Development; Disease; Event; Exocytosis; Exposure to; Gelatinases; Goals; Human; Immune response; In Vitro; Infection; Infection Control; Inflammation; Inflammation Mediators; Inflammatory; Injury; Intervention; Invaded; Knowledge; Laboratories; Lead; Leukocytes; MAP Kinase Gene; MAPK14 gene; Mediating; Membrane; Molecular; Molecular Target; NADPH Oxidase; Neutrophil Activation; Normal Cell; Oxidases; Patients; Peptidylprolyl Isomerase; Phosphorylation; Play; Poison; Population; Positioning Attribute; Process; Production; Proteins; Proteomics; Reagent; Relative (related person); Reperfusion Injury; Reporting; Rest; Rheumatoid Arthritis; Role; Secretory Vesicles; Signal Transduction Pathway; Testing; Therapeutic; Tissues; Toxin; Vasculitis; Veterans; Work; acute liver injury; bactericide; base; experience; extracellular; human CYBA protein; human disease; in vivo; killings; liver injury; lung vascular injury; microbial; neutrophil; novel; novel strategies; public health relevance; reactive oxygen intermediate; response; sound; therapeutic target; tool

DESCRIPTION (provided by applicant): Neutrophils are a critical component of both the innate and adaptive immune responses that control microbial invasion. Priming is an intermediate step by which resting neutrophils enhance their production of reactive oxygen intermediates (ROI) upon activation, and priming is necessary for optimal microbial killing. Although priming greatly enhances neutrophil bactericidal capability, primed neutrophils are also more dangerous to normal cells. Primed neutrophils participate in a number of diseases prominent in the aging Veteran population, including ANCA-associated vasculitis, ischemia- reperfusion injury, acute respiratory distress syndrome, rheumatoid arthritis, peridontitis, atherosclerosis, and acute inflammatory liver injury. Thus, manipulation of neutrophil priming is a potential therapeutic strategy for pharmacological intervention to restrain inflammation. Recent studies identified granule exocytosis and enhanced translocation of cytosolic components of the NADPH oxidase to the plasma membrane as possible mechanisms of neutrophil priming. However, many gaps in knowledge remain. The relative contribution of each of those events to priming has not been examined and whether both are necessary, or sufficient, for priming is unknown. The molecular events by which granule exocytosis contributes to priming and the molecular events that control enhanced translocation of cytosolic NADPH oxidase components are incompletely understood. Finally, the ability to manipulate neutrophil priming in vivo has not been established. The McLeish laboratory is in a unique position to address each of these gaps based on our extensive experience examining signal transduction pathways, our application of biochemical, genetic, and proteomic approaches to understand neutrophil biology, and our recent development of novel reagents that inhibit exocytosis in vitro and in vivo. The current proposal will address the central hypothesis that neutrophil priming results from the convergence of signal transduction pathways into two responses, an exocytose-dependent increase in plasma membrane expression of membrane components of NADPH oxidase and prolyl isomerase-dependent conformational changes in cytosolic components of NADPH oxidase. The following four specific objectives will be accomplished. Specific Objective 1 will test the working hypothesis that exocytosis of secretory vesicles and gelatinase granules results in increased plasma membrane expression of p91phox and p22phox, which is necessary, but not sufficient, for priming. Specific Objective 2 will test the working hypothesis that activation of the prolyl isomerase Pin1 contributes to priming of human neutrophils by multiple mechanisms, including enhanced p47phox translocation and increased granule exocytosis. Specific Objective 3 will test the working hypothesis that p38 MAPK phosphorylates multiple proteins that mediate events necessary for priming, including exocytosis and Pin1 activation. Specific Objective 4 will test the working hypothesis that neutrophil priming is a necessary component for neutrophil participation in inflammatory diseases and represents a viable therapeutic strategy, using an animal model of acute lung injury (ALI). The proposed work is expected to establish the molecular basis for neutrophil priming. The impact of the project is that molecular targets identified will permit therapeutic manipulation of neutrophil priming in inflammatory diseases. Thus, new approaches to treating Veteran patients with a number of acute and chronic inflammatory diseases are anticipated.

描述（由申请人提供）： 中性粒细胞是控制微生物入侵的先天性和适应性免疫反应的关键组成部分。启动是一个中间步骤，静息中性粒细胞在激活后增强其活性氧中间体 (ROI) 的产生，并且启动对于最佳微生物杀灭是必要的。虽然引发极大地增强了中性粒细胞的杀菌能力，但引发的中性粒细胞对正常细胞也更危险。活化的中性粒细胞参与了老年退伍军人群体中常见的许多疾病，包括 ANCA 相关血管炎、缺血再灌注损伤、急性呼吸窘迫综合征、类风湿性关节炎、牙周炎、动脉粥样硬化和急性炎症性肝损伤。因此，操纵中性粒细胞启动是药物干预抑制炎症的潜在治疗策略。最近的研究发现颗粒胞吐作用和 NADPH 氧化酶胞质成分向质膜的增强易位是中性粒细胞启动的可能机制。然而，知识方面仍然存在许多差距。这些事件中的每一个对启动的相对贡献尚未得到检验，并且这两个事件对于启动是否是必要的或充分的尚不清楚。颗粒胞吐作用促进启动的分子事件和控制胞质 NADPH 氧化酶成分增强易位的分子事件尚不完全清楚。最后，体内操纵中性粒细胞启动的能力尚未确定。麦克利什实验室在解决这些差距方面处于独特的地位，基于我们检查信号转导途径的丰富经验，我们应用生化、遗传和蛋白质组学方法来了解中性粒细胞生物学，以及我们最近开发的抑制中性粒细胞胞吐作用的新型试剂。体外和体内。目前的提案将解决以下核心假设：中性粒细胞启动是由信号转导途径汇聚成两种反应引起的，即NADPH氧化酶膜成分质膜表达的胞吐酶依赖性增加和NADPH胞质成分的脯氨酰异构酶依赖性构象变化氧化酶。将实现以下四个具体目标。 具体目标 1 将检验以下工作假设：分泌囊泡和明胶酶颗粒的胞吐作用导致 p91phox 和 p22phox 质膜表达增加，这对于启动是必要的，但还不够。具体目标 2 将检验以下工作假设：脯氨酰异构酶 Pin1 的激活有助于通过多种机制启动人类中性粒细胞，包括增强的 p47phox 易位和增加的颗粒胞吐作用。具体目标 3 将检验以下工作假设：p38 MAPK 磷酸化多种蛋白质，这些蛋白质介导启动所需的事件，包括胞吐作用和 Pin1 激活。具体目标 4 将测试 使用急性肺损伤（ALI）动物模型，假设中性粒细胞启动是中性粒细胞参与炎症性疾病的必要组成部分，并且代表了一种可行的治疗策略。拟议的工作预计将为中性粒细胞启动建立分子基础。该项目的影响在于，确定的分子靶点将允许对炎症性疾病中的中性粒细胞启动进行治疗操作。因此，预计会出现治疗患有多种急性和慢性炎症性疾病的退伍军人患者的新方法。