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

阿司匹林急性呼吸道疾病（AERD）患者表现出选择性气道 对白三烯（LT）E4的高反应性，其机制尚不清楚。这个项目测试了一部小说的作用 LTE4受体GPR99介导LTE4对皮肤和肺血管渗漏的有效作用 在小鼠中，以及在介导尘螨诱导的肺炎症模型中， 通过涉及血小板、P2Y12受体和前列腺素类的途径引起病理学改变。我们发现缺乏 CysLT 1 R和CysLT 2 R（Cysltr1/Cysltr2-/-小鼠）均表现出显着增加和延长的血管 相对于野生型（WT）对照，对皮内施用的LTE4的渗透性反应，以及 增强的肺血管渗漏响应于LTE4。Cysltr1/Cysltr2-/-小鼠也显示皮肤和 肺血管渗漏至LTC4和LTD4，相当于WT小鼠中的那些。此外，委员会认为， Cysltr1/Cysltr2-/-小鼠在IgE依赖性血管通透性反应中表现出显著增强和延长。 PCA，表明CysLTER介导响应于半胱氨酰半胱氨酸引起的耳肿胀。 由活化的肥大细胞释放的白三烯（cys-LTs）。最后，鼻内致敏和激发 屋尘螨提取物在Cysltr1/Cysltr2-/-中激发大量cys-LT依赖性肺部炎症 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以独立于CysLT1R或CysLT2R发生。我们已经将GPR99确定为候选者 基于初步体外研究的LTE4受体。目的1是进一步在体外表征GPR99， 产生证明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适应性免疫应答。目的2 是为了确定GPR99对Cys-LT依赖性肥大细胞介导的血管渗漏的贡献， Cysltr1/Cysltr2-/-小鼠的皮肤。目的3是确定GPR99对cys-LT依赖性细胞凋亡的贡献。 Cysltr1/Cysltr2-/-小鼠中变应原诱导的Th2细胞介导的肺嗜酸性粒细胞炎症。我们将 还测定了来自AERD个体和阿司匹林耐受对照的细胞中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.