Cellular Basis of Hypersensitivity Diseases in Humans

描述（由申请人提供）：该合作和协同计划项目的中心焦点针对肥大细胞（MC）的发育生物学和功能以及半胱氨酰白三烯生成途径的调节和功能，现在与先天性和适应性免疫炎症交叉。正在进行的方法是扩大了研究的配体培养衍生的人MC（hMCs），小鼠与有针对性的破坏的关键蛋白质参与的表达或功能的效应器通路的过敏/哮喘炎症，并通过比较细胞从哮喘捐助者与那些从正常人看到失调的反应。白细胞免疫球蛋白样受体（LIR）家族由嗜碱性粒细胞、嗜酸性粒细胞、嗜中性粒细胞和MC祖细胞（MCp）上的活化性LIR 7和抑制性LIR 3代表。 激活LIR 7的共连接释放来自嗜酸性粒细胞的预先形成的介质、半胱氨酰白三烯（cysLT）和细胞因子，并且LIR 3在嗜碱性粒细胞上的同时共连接防止这种应答。因此，项目1在慢性哮喘患者的特定效应细胞的表达和功能水平上寻求这种先天途径的失调。溶血磷脂酸（LPA）在其生理浓度下在谱系定向细胞因子的存在下不仅替代血清，而且还驱动脐带血祖细胞增殖和成熟为组成型表型的认识揭示了具有基于炎症的扩增潜力的血管周围MC的可能的稳态信号。人和小鼠之间三种公认的LPA受体（LPAR）的高度同源性表明，可以在小鼠品系中研究配体的皮肤和肺部效应，最初在项目2中的LPA 1 R无效品系中评估靶向破坏。 在项目3中，LTC 4合酶（LTC 4S）和半胱氨酰白三烯1受体（CysLT 1 R）无效菌株、正在开发的CysLT 2 R无效菌株和人LTC 4S基因转基因菌株的产生允许在急性和慢性免疫性肺损伤模型中评估cysLT途径产物。用培养衍生的hMC观察到的LTC 4S的IL-4诱导可以用小鼠MC复制，这一发现允许使用无效菌株来剖析调节信号。MCp的跨内皮运动和迁移对其基于组织的分布、成熟和表型表达至关重要，需要CXCR 2和C4 J37来归巢到肠而不是肺。在项目4中，气溶胶抗原诱导的肺部和肠道炎症模型将再次使用空菌株和阻断mAb来揭示每个器官中MCp池扩增所需的共同或独特途径。两者合计，这些研究将提供新的信息的滋补控制的效果或细胞功能的竞争LIR，对先天性调节的MC表型的血清LPA，对MC LTC 4S基因的表达调控，和组织特异性归巢和招募MCp的分布和表型成熟。

DESCRIPTION (provided by applicant): The central focus of this collaborative and synergic program project directed to the developmental biology and function of the mast cell (MC) and the regulation and function of the cysteinyl leukotriene-generating pathway now intersects with both innate and adaptive immune inflammation. The ongoing approach is broadened by studies of ligands for culture-derived human MCs (hMCs), of mice with targeted disruptions of the key proteins involved in expression or function of the effector pathways of allergic/asthmatic inflammation, and by a capacity to compare cells from asthmatic donors with those from normal individuals to see dysregulated responses. The leukocyte immunoglobulin-like receptor (LIR) family is represented by an activating LIR7 and an inhibitory LIR3 on basophils, eosinophils, neutrophils, and MC progenitors (MCp). Coligation to activate LIR7 releases preformed mediators, cysteinyl leukotrienes (cysLTs), and cytokines from eosinophils and simultaneous coligation of LIR3 on basophils prevent this response. Thus, Project 1 seeks dysregulation of this innate pathway at the expression and function levels for particular effector cells of patients with chronic asthma. The recognition that lysophosphatidic acid (LPA) at its physiologic concentration in the presence of lineage-directed cytokines not only replaces serum, but also drives proliferation and maturation of cord blood progenitors into a constitutive phenotype reveals a possible homeostatic signal for the perivascular MC with potential for inflammation-based amplification. The high homology of the three recognized LPA receptors (LPARs) between human and mouse suggests that the ligand can be studied for cutaneous and pulmonary effects in the mouse strains with targeted disruptions initially assessed in the LPA1R null strain in Project 2. In Project 3, the generation of LTC4 synthase (LTC4S) and cysteinyl leukotriene 1 receptor (CysLT1R) null strains, the CysLT2R null strain under development, and a strain transgenic for the human LTC4S gene allows assessment of the cysLT pathway products in models of acute and chronic immunologic pulmonary injury. The finding that IL-4 induction of LTC4S observed with culture-derived hMCs can be replicated with mouse MCs allows dissection of the regulatory signals using null strains. The transendothelial movement and migration of MCp essential to their tissue-based distribution, maturation, and phenotypic expression requires (_4J37 and CXCR2 for homing to intestine but not lung. In Project 4, a model of aerosol antigen-induced pulmonary and intestinal inflammation will again use null strains and blocking mAbs to reveal the common or unique pathways required for expansion of the MCp pool in each organ. Taken together, these studies will provide new information on the tonic control of effect or cell functions by competing LIRs, on the innate regulation of the MC phenotype by serum LPA, on the regulated expression of the MC LTC4S gene, and on the tissue-specific homing and recruitment of MCp for distribution and phenotypic maturation.