Eosinophil trafficking in fungal allergic asthma

描述（由申请人提供）：哮喘是一种慢性肺部疾病，影响3410万美国人，每年花费197亿美元。在哮喘的背景下，真菌致敏呈现出难以治疗的严重临床情况，导致不成比例的大量急诊中心就诊和住院。我们研究的长期目标是了解嗜酸性粒细胞在过敏性肺和真菌暴露背景下的有益和有害作用。本申请的目的是将肺腔中嗜酸性粒细胞的募集和运输与称为血管活性肠肽（VIP）的神经肽的信号传导联系起来。我们的中心假设是VIP通过自分泌机制，通过其VPAC 2受体发出信号，以调节嗜酸性粒细胞的募集（化学运动）和MMP 9的产生（侵袭），促进其进入肺腔。这一假设是基于我们先前发表的工作，显示真菌攻击后VPAC 2缺陷小鼠肺腔中嗜酸性粒细胞显著减少。明确引导嗜酸性粒细胞运输的分子机制将提供调节这些细胞的靶点，以帮助促进其潜在的益处并限制其病理作用，这是这项工作的基础。我们将以两个具体目标来检验我们的中心假设。我们将确定：1）VIP/VPAC 2自分泌信号传导控制嗜酸性粒细胞流出到肺腔的程度和2）VPAC 2信号传导对于嗜酸性粒细胞中MMP 9从头表达是必需的。这些目标将利用VPAC 2野生型（C57 BL/6）和敲除小鼠在烟曲霉过敏性哮喘的吸入模型，这是由我们的研究小组开发的。目的一是提供证据表明VIP/VPAC 2的自分泌回路激活了对肺募集至关重要的嗜酸性粒细胞中的趋化因子程序。目的二是通过MMP 9启动子诱导嗜酸性粒细胞的表达和分泌，将嗜酸性粒细胞的染色质结构重组到允许状态，从而建立嗜酸性粒细胞侵入肺腔的分子机制。该提案的创新之处在于将神经肽信号传导与解释体内真菌过敏性哮喘模型中的嗜酸性粒细胞增多症联系起来，以改善NDSU学生在分子（Dorsam博士）和全身建模（Schuh博士）方面的培训，并通过Hirohito Kita博士（嗜酸性粒细胞技术，马约诊所）和Sinisa Dovat博士（染色质重塑，好时医学院）的临床实验室举办的培训合作。

DESCRIPTION (provided by applicant): Asthma is a chronic pulmonary condition affecting 34.1 million Americans with an annual cost of $19.7 billion. Sensitization to fungi in the context of asthma presents a severe clinical scenario that is difficult to treat, accounting for a disproportionately large number of emergency center visits and hospitalizations. The long term goal of our research is to understand the beneficial and detrimental effects of eosinophils in the context of the allergic lung and fungal exposure. The objective of this application is to link recruitment and trafficking of eosinophils in the lung lumen to signaling by a neuropeptide called vasoactive intestinal peptide (VIP). Our central hypothesis is that VIP, through an autocrine mechanism, signals through its VPAC2 receptor to regulate recruitment (chemokinesis) and MMP9 production (invasion) of eosinophils, facilitating their entry to the lumen of the lung. This hypothesis is based on our previously published work showing a significant reduction of eosinophils in the lung lumen of VPAC2 deficient mice after fungal challenge. Defining the molecular mechanisms that guide eosinophil trafficking will provide targets to regulate these cells to help facilitate their potential benefits and limit their pathologic effects and is the ratonale for this work. We will test our central hypothesis with two specific aims. We will determine the extent to which: 1) VIP/VPAC2 autocrine signaling controls eosinophil egression into the pulmonary lumen and 2) VPAC2 signaling is necessary for MMP9 de novo expression in eosinophils. These aims will utilize VPAC2 wild type (C57BL/6) and knockout mice in an inhalation model of Aspergillus fumigatus allergic asthma that was developed by our research team. Aim one will provide evidence that an autocrine loop of VIP/VPAC2 activates a chemokenetic program in eosinophils critical for lung recruitment. Aim two will establish a molecular mechanism for eosinophil invasion into lung lumen by restructuring the chromatin architecture to a permissive state at the MMP9 promoter inducing its expression and secretion. The innovation for this proposal is connecting neuropeptide signaling to explain eosinophilia in an in vivo fugal allergic asthma model to improve training of NDSU students in molecular (Dr. Dorsam) and whole-body modeling (Dr. Schuh) and through training collaborations hosted in the clinical laboratories of Dr. Hirohito Kita (eosinophil techniques, Mayo Clinic) and Dr. Sinisa Dovat (chromatin remodeling, Hershey Medical School).