Airway Th2Th17 Cells in Refractory Asthma

摘要 治疗难治是哮喘相关发病率和死亡率的主要原因。难治性哮喘 占哮喘的直接成本的大部分。人们普遍认为哮喘是 不同的是，同样的治疗方法不会对所有人都起作用。治疗全面性哮喘失败的方法 发现人群对哮喘的特定内型有利(例如，嗜酸性粒细胞中的抗IL5抗体 哮喘)。为此，确定基于机制的哮喘亚型(内型)和 机制靶向治疗的发展是至关重要的。使用基于流式细胞术的 支气管肺泡灌洗(BAL)细胞的特性我们最近报道了一种新的鉴定 哮喘的一种内型，其特征是呼吸道中双阳性的Th2/Th17细胞占优势。这 Th2/Th17占优势的内型不同于Th2占优势和Th2/Th17较低的内型 有更严重的哮喘和对包括类固醇在内的治疗更难治。这样做的目的是 建议对这种以Th2/Th17为主的严重难治性哮喘内型进行研究。我们提出4个具体的建议 目标。在特定目标1下，我们将鉴定哮喘患者呼吸道中双阳性的Th2/Th17细胞。 明确以Th2/Th17为主的哮喘的表型。我们将进行支气管肺泡灌洗， 难治性哮喘患者的支气管镜活检和刷检。我们将描述细胞因子和 流式细胞仪和RNA-seq法检测BAL Th2/Th17细胞表面标志物。通过对组织的分析 组织病理学，肺生理，免疫学和临床特征，我们将确定独特的表型 与Th2/Th17细胞产生Th17细胞因子有关的特征。特定目标2将 探讨哮喘患者呼吸道Th2/Th17细胞的发育机制。我们将研究IL1β的作用 Th2细胞转分化为Th2/Th17细胞的危险相关分子模式。在……下面 具体目的3我们将阐明Th2/Th17细胞类固醇耐药的信号机制。细胞因子 诱导Th2/Th17细胞也激活了MEK和p38MAPK信号通路。我们将研究这一角色 在诱导类固醇耐药的信号分子中。我们将研究MEK对 糖皮质激素受体相关辅阻遏子SMRT、p38对糖皮质激素受体的调节 磷酸化，以及这些事件对类固醇耐药性的后果。《特定目标4》将考察 白细胞介素1α和白细胞介素8在中性粒细胞哮喘发病机制中的作用 哮喘。我们还将研究Th2细胞因子在阻止中性粒细胞流入呼吸道中的作用。 哮喘以Th2/Th17为主。这项研究之所以重要，是因为它确定了一部小说的特征 重症难治性哮喘的内型。我们将实施侵入性手术并检查支气管肺泡 为绝大多数实验灌洗细胞和支气管组织，这与哮喘有直接关系。这个 阐明Th2/Th17细胞发育的分子机制及其对类固醇的耐药性将为 已有的治疗重症难治性哮喘Th2/Th17内型药物的临床试验方法。

ABSTRACT Refractoriness to treatment is a major cause of asthma-related morbidity and mortality. Refractory asthma accounts for the bulk of the direct cost for asthma. There is a general consensus that asthma is heterogeneous and that the same treatment will not work for all. Treatments that failed in general asthma population were found beneficial to a specific endotype of asthma (e.g. anti-IL5 antibody in eosinophilic asthma). For this reason identification of mechanism-based subtypes (endotypes) of asthma and development of mechanism-targeted treatment are of paramount importance. Using flow cytometry-based characterization of bronchoalveolar lavage (BAL) cells we have recently reported the identification of a novel endotype of asthma that is characterized by the dominance of dual positive Th2/Th17 cells in the airways. This Th2/Th17 predominant endotype distinguishes itself from the Th2 predominant and Th2/Th17 low endotypes with more severe asthma and greater refractoriness to treatment including steroids. The objective of this proposal is to study this Th2/Th17 predominant endotype of severe refractory asthma. We propose 4 specific aims. Under specific aim 1 we will characterize dual positive Th2/Th17 cells in airways from asthmatic patients and define the phenotype of Th2/Th17 predominant asthma. We will perform bronchoalveolar lavage, endobronchial biopsy and brushing in refractory asthmatic patients. We will characterize the cytokine and surface marker profile of BAL Th2/Th17 cells by flow cytometry and RNA-seq. Through analyses of tissue histopathologic, pulmonary physiologic, immunologic & clinical features we will identify unique phenotypic characteristics that are associated with the production of Th17 cytokines by Th2/Th17 cells. Specific aim 2 will examine the mechanism of development of airway Th2/Th17 cells in asthma. We will examine the role of IL1β and danger-associated molecular patterns in transdifferentiation of Th2 cells into Th2/Th17 cells. Under specific aim 3 we will delineate the signaling mechanism of steroid resistance of Th2/Th17 cells. The cytokines that induce Th2/Th17 cells also activate the MEK and p38 MAPK signaling pathways. We will examine the role of these signaling molecules in induction of steroid resistance. We will examine MEK regulation of the glucocorticoid receptor-associated co-repressor SMRT, p38 regulation of glucocorticoid receptor phosphorylation, and the consequences of these events for steroid resistance. Specific aim 4 will examine the role of IL1α and IL8 in the pathogenesis of neutrophilic asthma, another steroid resistant form of refractory asthma. We will also examine the role of Th2 cytokines in preventing neutrophil influx into the airways in Th2/Th17 predominant asthma. The study is important because it identifies and characterizes a novel endotype of severe refractory asthma. We will perform invasive procedures and examine bronchoalveolar lavage cells and bronchial tissue for vast majority of experiments, which has direct relevance for asthma. The delineation of the molecular mechanism of Th2/Th17 cell development and its steroid resistance will pave the way for clinical trials of already existing therapeutic agents in Th2/Th17 endotype of severe refractory asthma.