Transcellular Communication in Airway Inflammation and Airway Hyperresponsiveness

气道炎症和气道高反应性中的跨细胞通讯

• 批准号: 7571603
• 负责人: ALAN Richard LEFF
• 金额: $ 38.38万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-04-01 至 2011-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7571603
• 关键词: Acute; Adhesions; Allergens; Asthma; Binding; Bone Marrow; Cell Adhesion Molecules; Cell membrane; Cells; Chronic; Coculture Techniques; Communication; Cultured Cells; Cytosolic Phospholipase A2; Data; Enzymes; Epithelial Cells; FPR1 gene; GTP-Binding Proteins; Generations; Human; Hydrolysis; ITGAM gene; Immune; Inflammatory; Integrins; Intercellular adhesion molecule 1; Knock-out; Knockout Mice; Lecithin; Left; Leukotriene C4; Lysophosphatidylcholines; Lysophospholipids; Mediating; Mediation; Membrane; Modeling; Mus; Nonesterified Fatty Acids; Pathway interactions; Phospholipase A2; Phosphorylation; Physiological; Production; Protein Isoforms; Protein Tyrosine Kinase; Proteins; Research Personnel; Reverse Transcriptase Polymerase Chain Reaction; Role; Signal Induction; Signal Transduction; Smooth Muscle Myocytes; Specificity; Surface; Testing; Up-Regulation; airway hyperresponsiveness; airway inflammation; base; cell motility; chemokine; cysteinyl-leukotriene; cytokine; eosinophil; extracellular; granulocyte; group V phospholipase A2; in vitro Model; in vivo; macrophage; methacholine; migration; mouse model; mutant; neutralizing monoclonal antibodies; novel; overexpression; programs; respiratory smooth muscle; uptake

DESCRIPTION (provided by applicant): Studies are proposed to examine the mechanisms by which epithelial cells (EPI), macrophages (MO) and airway smooth muscle cells (ASMC) are activated to communicate signals for granulocyte a) adhesion /migration, b) generation of LTC4, and c) conversion of normally reactive airways into hyperresponsive airways. The central hypothesis is that the endogenous 14 kDa group V PLA2 (gVPLA2) secreted from stimulated EPI, MO or ASMC serves as an intercellular messenger protein that is highly expressed in asthmatic human airways and is inducible during immune sensitization in mouse EPI, MO and ASMC. It is hypothesized that gVPLA2 hydrolyzes the phosphatidylcholine-rich outer plasma membrane of eosinophils to cause subsequent LTC4 secretion by a novel mechanism that is independent of cPLA2 activation. In Aim 1, studies are proposed to examine the hypothesis that [32-integrin-mediated eosinophil adhesion is regulated by gVPLA2 by a novel mechanism independent of MAPK-mediated cPLA2 phosphorylation. Studies are proposed to demonstrate that gVPLA2 secreted from airway resident cells transmits the signal for induction of (32-integrin adhesion in eosinophils. Further studies are proposed to elucidate the potential pathway by which adhesion is induced under physiological conditions by gVPLA2. In Aim 2, studies are proposed to examine the cellular entry and intracellular action of endogenous gVPLA2 in mediating augmented secretion of LTC4 during transcellular communication. Further studies are proposed to test the specificity of gVPLA2 by using a neutralizing mAb against gVPLA2 or TAT-dn-cPLA2. In Aim 3, studies are proposed to examine the mechanisms of gVPLA2 and cPLA2 in the mediation of airway inflammation and airway hyperresponsiveness (AHR) in acute and chronic murine models of asthma. Based upon preliminary data, studies are proposed to test the hypothesis that endogenous secretion of gVPLA2 mediates AHR in immune sensitized mice. The effect of MCL-3G1, a mAb against gVPLA2, in blocking AHR to methacholine or gVPLA2 challenge in pre/post OA-challenge mice will be assessed. Further studies using immune-sensitized gVPLA2-knockout and cPLA2-knockout mice will be generated to establish the specific role of these enzymes in AHR and inflammatory cell migration in vivo. Data derived from these studies should elucidate a new endogenous mechanism of transcellular communication that initiates airway inflammation and AHR.

描述（由申请方提供）：拟定研究旨在检查上皮细胞（EPI）、巨噬细胞（MO）和气道平滑肌细胞（ASMC）被激活以传递粒细胞信号的机制a）粘附/迁移，B）生成LTC 4，和c）正常反应性气道转化为高反应性气道。中心假设是从刺激的EPI、MO或ASMC分泌的内源性14 kDa V组PLA 2（gVPLA 2）充当细胞间信使蛋白，其在哮喘人气道中高度表达，并且在小鼠EPI、MO和ASMC中的免疫致敏期间是可诱导的。假设gVPLA 2水解嗜酸性粒细胞的富含磷脂酰胆碱的外质膜，通过独立于cPLA 2活化的新机制引起随后的LTC 4分泌。在目的1中，提出了研究来检验这样的假设，即β 2-整合素介导的嗜酸性粒细胞粘附由gVPLA 2通过独立于MAPK介导的cPLA 2磷酸化的新机制来调节。提出研究以证明从气道驻留细胞分泌的gVPLA 2传递诱导嗜酸性粒细胞中β 2-整联蛋白粘附的信号。提出进一步的研究来阐明在生理条件下由gVPLA 2诱导粘附的潜在途径。在目的2中，提出了研究来检查内源性gVPLA 2在跨细胞通讯期间介导增加的LTC 4分泌中的细胞进入和细胞内作用。建议进一步研究通过使用针对gVPLA 2或TAT-dn-cPLA 2的中和mAb来测试gVPLA 2的特异性。在目的3中，提出研究在急性和慢性哮喘小鼠模型中检查gVPLA 2和cPLA 2在气道炎症和气道高反应性（AHR）的介导中的机制。基于初步的数据，提出了研究来检验免疫致敏小鼠中gVPLA 2的内源性分泌介导AHR的假设。将评估MCL-3G 1（一种抗gVPLA 2的mAb）在OA激发前/后小鼠中阻断乙酰甲胆碱或gVPLA 2激发的AHR的作用。使用免疫致敏的gVPLA 2敲除和cPLA 2敲除小鼠的进一步研究将产生，以确定这些酶在体内AHR和炎性细胞迁移中的特定作用。从这些研究中获得的数据应该阐明一个新的内源性跨细胞通讯机制，启动气道炎症和AHR。