MAST CELL DEVELOPMENT IN VIVO AND PULMONARY RESPONSIVENESS

肥大细胞体内发育和肺部反应

• 批准号: 6109815
• 负责人: KARL FRANK AUSTEN
• 金额: $ 28.57万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-01 至 1999-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6109815
• 关键词: cell differentiation; cholinergic agents; cytokine; endopeptidases; immunocytochemistry; in situ hybridization; inflammation; laboratory mouse; mast cell; molecular cloning; respiratory hypersensitivity

Through their activation-dependent release of preformed secretory granule mediators, membrane lipid-derived mediators, and proinflammatory cytokines, mast cells are likely to contribute to the pathogenesis of bronchial asthma. In contrast to most other cells of the hematopoietic system, mast cells leave the bone marrow as unrecognized progenitors, circulate through the bloodstream, and undergo essentially all of their further development at multiple tissue sites. Studies utilizing a limited number of late-expressed mast cell phenotypic characteristics such as histochemical staining indicate that the tissue microenvironment of the mast cell is likely to dictate the final mature phenotype, but there is little knowledge about the developmental stages between the bone marrow progenitor and mature tissue mast cells in vivo. The molecular cloning of seven murine mast cell-specific proteases, including several that are expressed preferentially by immature, bone marrow culture- derived mst cells, affords the means to identify early mast cell progenitors in situ and to elucidate the tissue-defined steps of mast cell development, so as to gain an appreciation of how mast cells acquire their phenotypic diversity in vivo. The first Specific Aim will use immunocytochemical and in situ hybridization assessments of mast cell protease gene expression to define the development of mast cells in mast cell-deficient WBB6F1-W/Wv mice that have been infused with bone marrow cells from congenic normal mice to elicit the development of mast cells from the donor progenitor cells. Because of the paucity of intestinal mucosal mast cells in mice, this approach may favor the recognition of mast cells of the micro-vascular connective tissue; therefore, we will also analyze in kinetic protocols the development of mast cells in helminth-infected normal mice, whose mast cell progenitors and mucosal mast cell numbers are elevated. The second Specific Aim will determine with a combination of in situ hybridization and immunochemical approaches the spectrum of cytokines that are expressed by mast cells developing at multiple tissue sites, including tracheobronchial mast cells, in the two models studied in the first Specific Aim. The third Specific Aim of this project will seek to determine which constituent(s) of mast cells causes the mast cell-dependent pulmonary hyperresponsiveness to methacholine that occurs in three mouse models: after intravenous infusion of anti- IgE, after inhalation of ozone, and after active sensitization to ragweed allergen followed by aerosolized challenge. To achieve this aim, we will assess pulmonary hyperresponsiveness in the three models with mice generated in Project 4 that fail to express one or more mast cell proteases through targeted gene disruption. By using inhibitors of LTC4 and receptor antagonists of 5-hydroxytryptamine, we will also determine if these mast cell mediators contribute to the development of hyperresponsiveness. Overall, the studies in this project are expected to generate new insights into the in vivo developmental biology of mast cells and the contribution of their mediators to pulmonary hyperresponsiveness, a hallmark of bronchial asthma.

通过它们的激活依赖性释放预先形成的分泌颗粒 介质、膜脂源性介质和促炎症介质 细胞因子，肥大细胞可能有助于发病机制 支气管哮喘 与大多数其他造血细胞相比， 系统，肥大细胞作为未识别的祖细胞离开骨髓， 通过血液循环，并经历基本上所有的 在多个组织部位进一步发育。 研究利用了 有限数量的晚期表达肥大细胞表型特征 例如组织化学染色表明组织微环境 肥大细胞的分化可能决定最终的成熟表型，但 关于骨骼的发育阶段， 骨髓祖细胞和成熟组织肥大细胞。 分子 克隆了七种鼠肥大细胞特异性蛋白酶，包括几种 它们优先在未成熟的骨髓培养中表达 衍生的MST细胞，提供了鉴定早期肥大细胞的方法， 原位祖细胞，并阐明肥大细胞的组织定义步骤 细胞发育，以便了解肥大细胞如何获得 它们在体内的表型多样性 第一个具体目标将使用 肥大细胞免疫细胞化学和原位杂交研究 蛋白酶基因表达来定义肥大细胞在肥大细胞中的发育 已输注骨髓的细胞缺陷型WBB 6 F1-W/Wv小鼠 从同类正常小鼠的细胞中诱导肥大细胞的发育 从捐赠者的祖细胞中分离出来 由于缺乏肠道 小鼠粘膜肥大细胞，这种方法可能有利于识别 肥大细胞的微血管结缔组织;因此，我们将 还分析了在动力学协议中肥大细胞的发展， 蠕虫感染的正常小鼠，其肥大细胞祖细胞和粘膜 肥大细胞数量增加。 第二个具体目标将决定 结合原位杂交和免疫化学方法 由肥大细胞表达的细胞因子谱， 多个组织部位，包括气管支气管肥大细胞，在两个 在第一个具体目标中研究的模型。 第三个具体目标 该项目将寻求确定肥大细胞的哪种成分导致 乙酰甲胆碱诱导肺肥大细胞高反应性 这发生在三种小鼠模型中：静脉输注抗- IgE，吸入臭氧后和对豚草主动致敏后 过敏原，然后雾化攻击。 为达致这个目标，我们会 用小鼠评估三种模型中的肺高反应性 在项目4中产生的，未能表达一个或多个肥大细胞 蛋白酶通过靶向基因破坏。 通过使用LTC 4抑制剂 和5-羟色胺受体拮抗剂，我们还将确定 如果这些肥大细胞介质有助于发展 高反应性 总体而言，本项目的研究是预期的 对肥大细胞的体内发育生物学产生新的见解， 细胞及其介质对肺动脉高压的作用 高反应性是支气管哮喘的标志