Eosinophil trafficking in fungal allergic asthma

描述(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，真菌致敏是一种难以治疗的严重临床情况，占急救中心就诊和住院的不成比例的大量。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的背景下的有益和有害影响。这项应用的目的是将嗜酸性粒细胞在肺腔内的募集和运输与一种名为血管活性肠肽(VIP)的神经肽的信号传递联系起来。我们的中心假设是，VIP通过自分泌机制，通过其VPAC2受体发出信号，调节嗜酸性粒细胞的募集(趋化运动)和MMP9产生(侵袭)，促进它们进入肺腔。这一假设是基于我们之前发表的工作，该工作表明VPAC2缺陷小鼠在真菌攻击后肺腔中的嗜酸性粒细胞显着减少。确定引导嗜酸性粒细胞运输的分子机制将提供靶点来调节这些细胞，以帮助促进它们的潜在益处并限制它们的病理影响，这是这项工作的主要内容。我们将用两个具体目标来检验我们的中心假设。我们将确定：1)VIP/VPAC2自分泌信号控制嗜酸性粒细胞进入肺腔的程度；2)VPAC2信号是嗜酸性粒细胞MMP9从头表达所必需的。这些目标将利用VPAC2野生型(C57BL/6)和基因敲除小鼠在我们的研究小组开发的烟曲霉过敏性哮喘吸入模型中。目的一将提供证据表明VIP/VPAC2的自分泌循环激活了嗜酸性粒细胞中对肺招募至关重要的化学遗传学程序。目的二通过在MMP9启动子上重组染色质结构使其处于允许状态，诱导其表达和分泌，从而建立嗜酸性粒细胞侵入肺腔的分子机制。这项建议的创新之处在于通过连接神经肽信号来解释体内真菌过敏性哮喘模型中的嗜酸性粒细胞增多，以改善对南大学生在分子(Dorsam博士)和全身模型(Scheh博士)方面的培训，并通过在好时医学院嗜酸性粒细胞技术的临床实验室主持的培训合作和Sinisa Dovat博士(好时医学院染色质重塑)开展合作。

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).