Chemical Mediators of Acute Pulmonary Disorders

描述(由申请人提供)： 这是一项持续的合作努力，目的是了解肥大细胞(MC)相关效应器功能的调节以及这些过程与哮喘的相关性。在造血效应细胞中，MCs是独一无二的，因为它们在肺和其他血管组织中的组成性驻留，在先天性和获得性免疫反应的传入和传出阶段都有突出的贡献。该项目的中心假设是，MC通过其构成和诱导的效应通路，在先天性和获得性免疫反应与哮喘的临床表现之间形成功能桥梁。纯化的重组MC类胰蛋白酶的可获得性，以及缺乏合成丝氨酸蛋白多糖所需酶的小鼠菌株的发展，使得在体外和体内研究蛋白多糖在调节类胰蛋白酶的不同功能中的作用成为可能。一种新的体外方法将被用来确定GP49B1，一个带有基于免疫酪氨酸的抑制基序(ITIMs)的反向调节受体，通过机械上不同的受体来调节MC的激活，以限制过敏和天然免疫反应中MC依赖的病理反应。2号和6号染色体上与A/J小鼠内在MC依赖AHR相互作用的基因将被鉴定，这种表型对MC的依赖将通过过继转移MC到由于c-kit酪氨酸激酶突变而导致MC缺陷的A/J小鼠而得到证实。分别缺乏造血型PGD2合成酶(PGDS)和LTC4合成酶(LTC4S)的小鼠菌株，以及缺乏PGD2和LTC4受体的基因敲除菌株，将在体外和体内确定这些二十烷类化合物的互补和反向调节功能。采用一种新的体外培养方法，从具有良好特性的阿司匹林不耐受哮喘(AIA)供体中分离培养人巨噬细胞(HMCs)，研究支气管保护性二十聚糖、PGE2和诱导型PGE2合成酶在AIA中的作用。相关合成酶和PGE受体的异常将促使重新测序，以发现多态变异。PGE2在体外抑制HMC活化的受体和机制将被明确。这些研究共同提供了至关重要的信息，以了解关键的MC相关效应器功能的生化和遗传调节，并确定它们在控制内在AHR、炎症和组织修复中的作用，这些反应可能有助于哮喘的病理生理学。

DESCRIPTION (provided by applicant): This is a continuing, collaborative effort to understand the regulation of mast cell (MC)-associated effector functions and the relevance of these processes to asthma. MCs are unique among hematopoietic effector cells for their constitutive residence in the lung and other vascularized tissues, and their prominent contribution to both afferent and efferent phases of innate and adaptive immune responses. The central hypothesis of this Program Project is that MCs, by virtue of their constitutive and inducible effector pathways, form a functional bridge between innate and acquired immune responses and the clinical expression of asthma. The availability of purified recombinant MC tryptases and the development of mouse strains lacking the enzymes necessary to synthesize serglyin proteoglycans permits study of the role of proteoglycans in regulating the diverse functions of tryptases in vitro and in vivo. A novel in vitro approach will be used to define the mechanism by which GP49B1, a counterregulatory receptor bearing immunotyrosine-based inhibitory motifs (ITIMs), regulates MC activation through mechanistically diverse receptors to limit MC-dependent pathology in both allergic and innate immune esponses. The genes on mouse chromosomes 2 and 6 that interact to confer intrinsic MC-dependent AHR in A/J mice will be identified, and the MC-dependency of this phenotype will be confirmed with adoptive transfer of MCs into A/J mice rendered MC-deficient due to a mutation in the c-kit tyrosine kinase. Mouse strains lacking hematopoietic PGD2 synthase (PGDS) and LTC4synthase (LTC4S), respectively, as well as knockout strains lacking each receptor for PGD2 and LTC4, will be used to define the complementary and counterregulatory functions of these eicosanoids in vitro and in vivo. The role of the bronchoprotective eicosanoid, PGE2, and inducible PGE2 synthases in aspirin intolerant asthma (AIA) will be studied using a novel in vitro approach to the development of human MCs (hMCs) from well-characterized donors with AIA. Abnormalities in relevant synthases and PGE receptors will prompt resequencing for discovery of polymorphic variants. The receptors and mechanisms responsible for the inhibitory effects of PGE2 on hMC activation in vitro will be defined. These studies collectively provide information critical to understanding the biochemical and genetic regulation of key MC-associated effector functions, and defining their role in the control of intrinsic AHR, inflammation, and tissue repair subsequent to both allergic and innate immune responses that likely contribute to the pathophysiology of asthma.