Interplay between LTE4/LTE4 receptors and IFN-y with mast cells and eosinophils i

描述（由申请人提供）：这些研究将侧重于哮喘（和鼻窦炎）的细胞和免疫机制，因为它们与阿司匹林加重的呼吸道疾病（AERD）有关。我们的假设是AERD与阿司匹林耐受性哮喘形成对比，通过特异性受体作用的白三烯E4（LTE 4）的过度产生以及与白细胞介素（IL）-4和干扰素（IFN）-3的促炎相互作用。我们还假设阿司匹林直接诱导AERD中的细胞活化。AERD是一种综合征，由严重持续性哮喘、侵袭性气道重塑、广泛增生性嗜酸性鼻窦炎伴鼻息肉（NP）形成、嗅觉丧失和阿司匹林不耐受组成，其特征在于从鼻塞、鼻溢和喘息到危及生命的哮喘发作的症状。阿司匹林不耐受部分反映了白三烯C4合酶（LTC 4S）和半胱氨酰白三烯（CysLT）受体表达的增加，因此，这些患者具有组成性过度产生和对CysLT（特别是LTE 4）的反应性提高，其中在摄入阿司匹林后CysLT产生爆炸性增加。我们假设识别LTE 4的新受体与AERD的病理生理学相关。我们目前的研究利用了从AERD供体产生的永生化肥大细胞系（“LUVA”细胞）。这些细胞保留肥大细胞的相关特征，包括具有含有组胺的分泌颗粒和Fc 5 RI 1的表面表达。LUVA细胞提供了一种新的模型，用于研究阿司匹林直接激活肥大细胞的先前未探索的分子基础，它们响应于释放颗粒内容物，Ca+2通量，花生四烯酸产物和从头合成的趋化因子。这些细胞产生的分泌蛋白不是任何其他目前表征的嗜酸性粒细胞活化因子，其作用是促进嗜酸性粒细胞造血、存活和LTC 4S表达。我们将研究LUVA条件培养基（LCM）与嗜酸性粒细胞的相互作用，以进一步确定AERD病理生理学的核心机制。提出了三个具体目标：具体目标1将表征LTE 4通过LTE 4特异性受体在AERD中发挥作用的影响。具体目标2将阐述IL-4和IFN-3在AERD中的重要性。虽然特征在于严重的嗜酸性粒细胞增多，但通常与嗜酸性粒细胞增多相关的细胞因子（例如，IL-5）在AERD中仅适度和不稳定地表达，而AERD显示混合的Th 1（IFN-3）/Th 2（IL-4）细胞因子“特征”。我们将重点关注IFN-3在促进嗜酸性粒细胞增多和增强的LTC 4S表达和CysLT分泌中相对未探索的作用，这些是AERD的核心。我们将研究IFN-3使嗜酸性粒细胞对LTE 4应答的能力。最后，具体目标3将表征LUVA细胞及其对阿司匹林的响应活化。此外，我们将确定LUVA细胞分泌的因子，增强嗜酸性粒细胞造血和上调LTC 4S。 公共卫生相关性：阿司匹林加重的呼吸道疾病（AERD）占成人哮喘患者的5-20%，在严重哮喘患者中占比过高。AERD的许多特征知之甚少，包括白三烯产生和反应性的特异性上调的基础以及阿司匹林摄入后发生的细胞活化的机制。我们建议，这些白三烯通过独特的AERD受体的行为，他们与以前未开发的肥大细胞衍生的蛋白质和IFN-3，功能，可能被证明是治疗调制的目标相互作用。

DESCRIPTION (provided by applicant): These studies will focus on cellular and immune mechanisms of asthma (and sinusitis) as they pertain to aspirin-exacerbated respiratory disease (AERD). Our hypothesis is that AERD contrasts with aspirin tolerant asthma through excessive production of leukotriene E4 (LTE4) acting through specific receptors and a pro- inflammatory interplay with both interleukin (IL)-4 and interferon (IFN)-3. We also hypothesize that aspirin directly induces cellular activation in AERD. AERD is a syndrome consisting of severe persistent asthma, aggressive airway remodeling, extensive hyperplastic eosinophilic sinusitis with nasal polyp (NP) formation, anosmia, and an intolerance to aspirin characterized by symptoms ranging from nasal congestion, rhinorrhea, and wheezing to life-threatening asthma attacks. Aspirin intolerance reflects, in part, increased expression of leukotriene C4 synthase (LTC4S) and cysteinyl leukotriene (CysLT) receptor expression and, as a result, these patients have constitutive overproduction and heightened responsiveness to CysLTs (especially LTE4) with an explosive increase in CysLT production following ingestion of aspirin. We hypothesize that novel receptor(s) recognizing LTE4 are relevant to the pathophysiology of AERD. Our current studies take advantage of having generated an immortalized mast cell line ("LUVA" cells) derived from an AERD donor. These cells preserve relevant features of mast cells including possessing secretory granules containing histamine and surface expression of Fc5RI1. LUVA cells provide a novel model for investigating the previously unexplored molecular basis for direct mast cell activation by aspirin, to which they respond with release of granule contents, Ca+2 fluxes, arachidonate products, and de novo synthesized chemokines. These cells produce a secreted protein that is not any other currently characterized eosinophil-activating factor that acts to promote eosinophil hematopoiesis, survival, and LTC4S expression. We will investigate the interaction of LUVA conditioned medium (LCM) with eosinophils to further define mechanisms central to the pathophysiology of AERD. Three specific aims are proposed: Specific Aim 1 will characterize influences of LTE4 acting through LTE4-specific receptors in AERD. Specific Aim 2 will address the importance of IL-4 and IFN-3 in AERD. Although characterized by profound eosinophilia, cytokines typically associated with eosinophilia (e.g., IL-5) are only modestly and variably expressed in AERD, which instead displays a mixed Th1 (IFN-3)/Th2 (IL-4) cytokine "signature". We will focus on the relatively unexplored role of IFN-3 in promoting eosinophilia and the enhanced LTC4S expression and CysLT secretion that are central to AERD. We will investigate the ability of IFN-3 to render eosinophils responsive to LTE4. And finally, specific aim 3 will characterize LUVA cells and their activation in response to aspirin. In addition, we will define the factor secreted by LUVA cells that enhances eosinophil hematopoiesis and upregulation of LTC4S. PUBLIC HEALTH RELEVANCE: Aspirin-exacerbated respiratory disease (AERD) comprises 5-20% of adult asthmatics and is over-represented among severe asthmatics. Many features of AERD are poorly understood, including the basis for the pathognomonic upregulation of leukotriene production and responsiveness and the mechanism for the cellular activation that occurs after aspirin ingestion. We propose that these leukotrienes act through receptors unique to AERD and they interact with a previously unexplored mast cell-derived protein and IFN-3, features that may prove to be targets for therapeutic modulation.