Immune Responses of the Epithelium in Chronic Rhinosinusitis with Polyps

描述(由申请人提供)：慢性鼻窦炎合并息肉(CRSwNP)在美国是一个严重的健康问题。这种疾病通常对内科和外科治疗特别顽固，其特征是鼻窦粘膜持续的嗜酸性炎症，分泌物增厚，经常被细菌和/或真菌定植。CRSwNP背后的细胞和分子机制仍然知之甚少。鼻腔鼻道上皮细胞在上呼吸道的宿主免疫防御中起重要作用。它们表达模式识别受体，并产生抗微生物效应器，以应对吸入的病原体。鼻窦上皮细胞(SNECs)的固有免疫途径也促进针对细菌、病毒和真菌的Th1样炎症。然而，目前还没有发现SNECs的先天免疫程序会产生Th2样炎症。我们的初步研究有力地表明，这种先天免疫途径存在于SNECs中，重要的是，这一途径的激活下调了CRSwNP的先天抗微生物活性。我们假设CRSwNP中的SNECs受局部Th2细胞因子和特定的管腔病原体相关分子的影响，采取了一种“抗寄生虫”的先天免疫程序，其特征是表达嗜酸性粒细胞前介质，抑制抗微生物功能，从而促进CRSwNP的基本特征。为了进一步探索这一假设，在目标1中，我们首先将检查来自对照组和有鼻息肉和无鼻息肉的慢性鼻窦炎患者的组织样本，以充分表征体内抗寄生虫基因表达的模式。我们将在体外探索这种表型是否会导致SNECs对Toll样受体激动剂的抗微生物反应减少。在目标2中，我们将使用气液界面细胞培养系统通过暴露于Th2细胞因子和可能的寄生虫相关分子来驱动SNEC向抗寄生虫表型转变。我们将利用这一模型来描述其对先天抗微生物功能的影响，并确定潜在的分子机制。最后，在目标3中，我们将创建一种可诱导Th2鼻窦炎的转基因小鼠模型。我们将检查我们的小鼠模型是否概括了人类疾病的重要特征，并研究体内慢性鼻腔Th2炎症是否会导致先天抗微生物功能受损。该模型的发展将提供第一个慢性鼻窦炎转基因动物模型，这将为未来CRSwNP的广泛研究提供巨大的潜力。提案中描述的这些联合研究将极大地促进目前对CRSwNP的了解，并可能导致这种虚弱和昂贵的疾病的创新疗法。

DESCRIPTION (provided by applicant): Chronic rhinosinusitis with polyps (CRSwNP) is a significant health problem in the United States. This disorder, which is often particularly recalcitrant to medical and surgical therapy, is characterized by persistent eosinophilic inflammation of the sinonasal mucosa, with thickened secretions that are frequently colonized with bacteria and/or fungi. The cellular and molecular mechanisms that underlie CRSwNP remain poorly understood. Epithelial cells of the sinonasal tract play important roles in host immune defense of the upper airway. They express pattern recognition receptors and produce anti-microbial effectors in response to inhaled pathogens. Innate immune pathways of sinonasal epithelial cells (SNECs) also promote Th1-like inflammation to target bacteria, viruses, and fungi. However, there are no identified innate immune programs of SNECs that generate Th2-like inflammation. Our preliminary studies strongly suggest that such an innate immune pathway exists in SNECs and, importantly, that activation of this pathway down-regulates innate anti-microbial activity in CRSwNP. We hypothesize that SNECs in CRSwNP are influenced by local Th2 cytokines and particular lumenal pathogen-associated molecules to adopt an "anti-parasite" innate immune program, characterized by expression of pro-eosinophilic mediators and suppression of anti-microbial function, thus promoting the cardinal features of CRSwNP. To further explore this hypothesis, we will initially, in aim 1, examine tissue samples from control subjects and well-characterized patients with chronic rhinosinusitis with and without nasal polyps, to fully characterize the anti-parasite pattern of gene expression in vivo. We will explore in vitro whether this phenotype results in reduced anti-microbial responses by SNECs to toll-like receptor agonists. In aim 2, we will use an air-liquid interface cell culture system to drive SNECs to the anti-parasite phenotype through exposure to Th2 cytokines and putative parasite-associated molecules. We will utilize this model to characterize the effect on innate anti-microbial function and identify underlying molecular mechanisms. Finally, in aim 3 we will create a genetically-modified mouse model of inducible Th2 sinonasal inflammation. We will examine whether our mouse model recapitulates important features of the human disease, and study whether chronic sinonasal Th2 inflammation in vivo leads to impaired innate anti-microbial function. Development of this model will provide the first transgenic animal model of chronic rhinosinusitis, which will have great potential to further a wide range of future CRSwNP research. These combined studies described in the proposal will significantly advance current knowledge about CRSwNP and potentially lead to innovative therapies for this debilitating and costly medical condition.