Mechanisms and Receptors Responsible for Leukotriene E4 (LTE4)-dependant Pathobio

阿司匹林加重呼吸系统疾病(AERD)患者表现为选择性呼吸道 对白三烯(LT)E4的高反应性机制尚不清楚。这个项目测试了一部小说的角色 LTE4受体GPR99在介导LTE4对皮肤和肺血管渗漏中的作用 在小鼠中，以及在介导以Th2为主的尘肺模型的肺炎症中 通过涉及血小板、P2Y12受体和前列腺素类物质的途径进行病理。我们发现老鼠缺乏 CysLT1R和CysLT2R(Cysltr1/Cysltr2-/-小鼠)血管明显增多和延长 与野生型(WT)对照相比，皮内给药LTE4的通透性反应以及 对LTE4的反应增加肺血管渗漏。Cysltr1/Cysltr2-/-小鼠也表现出皮肤和 肺血管渗漏至LTC4和LTD4，与WT小鼠相当。此外， Cysltr1/Cysltr2-/-小鼠对IgE依赖的血管通透性反应显著增强并延长 PCA，表明CysLTER介导了对半胱氨酸基反应发生的耳肿胀 激活的肥大细胞释放白三烯(Cys-Lts)。最后，鼻腔敏化和挑战 屋尘螨提取物在Cysltr1/Cysltr2-/-细胞中诱导Cys-LT依赖的肺部炎症 小鼠，这意味着Cys-LT驱动的免疫细胞功能导致Th2细胞因子谱和肺 嗜酸性粒细胞增多症可独立于CysLT1R或CysLT2R发生。我们已将GPR99确定为候选人 基于初步体外研究的LTE4受体。目的1是进一步研究GPR99的体外特性和 产生需要证明GPR99是LTE4特异性受体所需的缺陷菌株 缺乏CysLT1R和CysLT2R的小鼠的血管和细胞先天性和获得性免疫反应。目标2 目的是确定GPR99在Cys-LT依赖的肥大细胞介导的血管渗漏中的作用。 Cysltr1/Cysltr2-/-小鼠的皮肤。目的3是确定GPR99对Cys-LT依赖的贡献 变应原诱导的Th2细胞介导的Cysltr1/Cysltr2-/-小鼠肺嗜酸性炎症。我们会 同时测定AERD患者和阿司匹林耐受对照组患者细胞中GPR99的表达。

Individuals with aspirin exacerbated respiratory disease (AERD) demonstrate selective airway hyperresponsiveness to leukotriene (LT)E4 by unclear mechanisms. This Project tests the role of a novel LTE4 receptor, GPR99, in mediating the potent effects of LTE4 on cutaneous and pulmonary vascular leak in mice, and in mediating Th2-dominated pulmonary inflammaton in a model of dust mite-induced pulmonary pathology by a pathway involving platelets, P2Y12 receptors, and prostanoids. We found that mice lacking both CysLT1R and CysLT2R (Cysltr1/Cysltr2-/- mice) show markedly increased and prolonged vascular permeability responses to intradermally administered LTE4 relative to wild-type (WT) controls, as well as an enhanced pulmonary vascular leak in response to LTE4. Cysltr1/Cysltr2-/- mice also show cutaneous and pulmonary vascular leak to LTC4 and LTD4 that are equivalent to those in WT mice. Moreover, Cysltr1/Cysltr2-/- mice show a markedly enhanced and prolonged vascular permeability response in IgE-dependent PCA, indicating that CysLTER mediates ear swelling occurring in response to the cysteinyl leukotrienes (cys-LTs) released by activated mast cells. Finally, intranasal sensitization and challenge with house dust mite extract elicits substantial cys-LT-dependent pulmonary inflammation in Cysltr1/Cysltr2-/- mice, implying that cys-LT-driven immune cell functions that lead to a Th2 cytokine profile and pulmonary eosinophilia can occur independently of CysLT1R or CysLT2R. We have identified GPR99 as a candidate receptor for LTE4 based on preliminary in vitro studies. Aim 1 is to further characterize GPR99 in vitro and to generate the deficient strains needed to prove that GPR99 is the LTE4-specific receptor that mediates vascular and cellular innate and adaptive immune responses in mice lacking CysLT1R and CysLT2R. Aim 2 is to determine the contribution of GPR99 to the cys-LT-dependent mast cell-mediated vascular leakage in the skin of Cysltr1/Cysltr2-/- mice. Aim 3 is to determine the contribution of GPR99 to the cys-LT-dependent allergen-induced Th2 cell mediated pulmonary eosinophilic inflammation in Cysltr1/Cysltr2-/- mice. We will also determine the expression of GPR99 in cells from individuals with AERD and aspirin-tolerant controls.