Immune Responses of the Epithelium in Chronic Rhinosinusitis with Polyps

描述（由申请人提供）：慢性鼻窦炎伴息肉（CRSwNP）在美国是一个重要的健康问题。这种疾病通常对药物和手术治疗特别难治，其特征是鼻窦粘膜持续的嗜酸性粒细胞炎症，伴有增厚的分泌物，经常有细菌和/或真菌定植。CRSwNP背后的细胞和分子机制仍然知之甚少。鼻窦上皮细胞在上呼吸道宿主免疫防御中起重要作用。它们表达模式识别受体，并在吸入病原体时产生抗微生物效应。鼻腔上皮细胞（snec）的先天免疫途径也促进th1样炎症靶向细菌、病毒和真菌。然而，目前还没有确定snc的先天免疫程序产生th2样炎症。我们的初步研究强烈表明，snec中存在这样的先天免疫途径，重要的是，该途径的激活下调了CRSwNP的先天抗微生物活性。我们假设CRSwNP中的snc受局部Th2细胞因子和特定管腔病原体相关分子的影响，采用“抗寄生虫”先天免疫程序，其特征是亲嗜酸性介质的表达和抗微生物功能的抑制，从而促进CRSwNP的基本特征。为了进一步探索这一假设，我们将首先在目标1中检查来自对照受试者和具有和不具有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模式。我们将在体外探索这种表型是否会导致snec对toll样受体激动剂的抗微生物反应降低。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细胞因子和假定的寄生虫相关分子，驱动snc达到抗寄生虫表型。我们将利用这个模型来描述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，我们将创建一个可诱导Th2鼻窦炎症的转基因小鼠模型。我们将检验我们的小鼠模型是否概括了人类疾病的重要特征，并研究体内慢性鼻窦Th2炎症是否会导致先天抗微生物功能受损。该模型的建立将为慢性鼻窦炎提供首个转基因动物模型，为进一步开展广泛的CRSwNP研究具有很大潜力。提案中描述的这些联合研究将显著推进当前关于CRSwNP的知识，并可能为这种使人衰弱且昂贵的医疗状况带来创新疗法。

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.