Mechanisms and Consequences of Eosinophil Integrin Activation

嗜酸性粒细胞整合素激活的机制和后果

• 批准号: 8044123
• 负责人: DEANE Fremont MOSHER
• 金额: $ 43.21万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8044123
• 关键词: Address; Adhesions; Adhesives; Allergic; Alpha Granule; Asthma; Blood; Blood Platelets; Blood specimen; Cell Membrane Proteins; Cells; Correlative Study; Endothelial Cells; Eosinophilia; Epitopes; Exhalation; Exposure to; Extracellular Matrix; Glycoproteins; Hand; ITGAM gene; In Vitro; Integrins; Interleukin-5; Lead; Learning; Ligands; Lung; Measurement; Measures; Mediating; Membrane; Metalloproteases; Movement; P-Selectin; Patients; Plasma; Proteolysis; Research; Role; Severities; Signal Pathway; Sputum; Structure; Surface; Testing; Time; Vascular Cell Adhesion Molecule-1; Weibel-Palade Bodies; Whole Blood; antigen challenge; asthmatic patient; cell motility; cell type; eosinophil; eosinophilic inflammation; trafficking; volunteer

This project focuses on the mechanism of activation of pi integrins on eosinophils (EOS) in the blood of patients with asthma; the role of such activation in selective movement of EOS into the airway; and'two phenomena that we hypothesize are important for movement of EOS within the airway, formation of podosomes and activation of aMp2 integrin. Aim 1 addresses the hypothesis'that interaction of blood EOS Pselectin glycoprotein ligand (PSGL) with P-selectin, which is normally sequestered in a-granules of platelets and Weibel-Palade bodies of endothelial cells, is responsible for enhanced p1 activation. This hypothesis will be tested by correlative studies of blood samples obtained from patients with asthma of varying severity and asthmatic volunteers studied after whole lung or segmental lung antigen challenge. Measurements will be made of the amounts of the N29 activation-sensitive epitope of pi on circulating EOS, P-selectin associated with circulating EOS, P-selectin on the surface of circulating platelets, and soluble P-selectin in plasma. In vitro studies will compare how the various forms of P-selectin enhance expression of the N29 epitope on EOS when added to blood and identify signaling pathways important for the increased expression. Aim 2 addresses the hypothesis that activation of a4p1, the major pi integrin on EOS, primes the EOS to arrest in vascular cell adhesion molecule (VCAM)-expressing vessels of asthmatic lung and thus enter the airway. We will correlate N29 epitope expression with various measures of eosinophilic inflammation in lung and relate the time course of changes of N29 expression after lung Ag challenge vis-a-vis changes in P-selectin. Parallel in vitro studies will test if P-selectin enhances EOS adhesion from whole blood under static and flow conditions and identify signaling pathways important for the increased adhesion. The podosome is a transient structure that mediates interaction with and proteolysis of adhesive ligands in extracellular matrix. The podosome of EOS, which forms when cells stimulated with IL-5 and/or TNF-a adhere via a4p1 to VCAM, has a distinctive set of associated cytoskeletal and cell membrane proteins when compared to podosomes of other cell types. Included within this set is the ADAMS membrane metalloproteinase. Aim 3 tests the hypotheses that podosomes and ADAMS contribute to the robust proteolytic capacity of adherent EOS; and that there is a "hand-off1 when the EOS enter the lung such that aMp2, which is activated upon exposure to IL-5, replaces a4p1, which is degraded in podosomes, as the principal adhesive integrin. The research will lead to a better understanding of trafficking of EOS in asthma and how trafficking may be modulated pharmacologically.

该项目侧重于在嗜酸性粒细胞（EOS）中激活Pi整合蛋白的机理（EOS） 哮喘患者；这种激活在EOS进入气道的选择性运动中的作用；和dotwo 我们假设的现象对于在气道中的EOS运动，足体形成很重要 和AMP2整联蛋白的激活。 AIM 1解决了血液EOS Pselectin的相互作用的假设 糖蛋白配体（PSGL）和P-选择蛋白通常在血小板的A颗粒中隔离 内皮细胞的微生甲状动物体负责增强P1激活。这个假设将会 通过对从严重程度不同的哮喘患者获得的血液样本的相关研究来测试 在整个肺或节肺抗原挑战之后，哮喘志愿者研究了。测量将是 由PI在循环EOS，P-选择蛋白相关的N29激活敏感性表位的量制成 带有循环的EOS，循环血小板表面上的P-选择素，以及血浆中的可溶性P-选择素。在 体外研究将比较各种形式的P-选择素如何增强N29表位的表达 EOS添加到血液中并识别信号通路对于增加表达很重要。目标2 解决了以下假设：EOS上的主要PI整合素A4P1激活EOS的素质 血管细胞粘附分子（VCAM）表达哮喘肺的血管，从而进入气道。我们 将将N29表位表达与肺中嗜酸性炎症的各种指标相关联 肺Ag挑战相对于p-选择素的肺Ag挑战后N29表达的变化的时间过程。 平行的体外研究将测试P-选择素是否增强静态和流动下全血的EOS粘附 条件并确定信号通路对于增加的粘附力很重要。小便是一个 瞬时结构，介导细胞外基质中粘合剂配体的相互作用和蛋白水解。 EOS的足迹，当用IL-5和/或TNF-A刺激细胞通过A4P1刺激细胞时形成 VCAM与相比具有独特的相关细胞骨架和细胞膜蛋白 其他细胞类型的足体。该组中包括Adams膜金属蛋白酶。目标3 测试了足体和亚当的假设，促进了粘附的稳健蛋白水解能力 eos;并且当EOS进入肺部时，有一个“移交1 接触IL-5，取代了A4P1，该A4P1作为主要粘合剂整合蛋白，降解在足体中。这 研究将使对哮喘中EOS的贩运以及贩运的方式更好地了解 在药理学上调节。