Airway Th2Th17 Cells in Refractory Asthma

摘要 治疗无效是哮喘相关发病率和死亡率的主要原因。难治性哮喘 占哮喘直接成本的大部分。人们普遍认为哮喘是 不同的人，同样的待遇不会适用于所有人。在一般哮喘中失败的治疗 发现对哮喘的特定内源型（例如嗜酸性粒细胞中的抗IL 5抗体）有益。 哮喘）。出于这个原因，基于机制的哮喘亚型（内源性）的鉴定， 机制靶向治疗的发展至关重要。使用基于流式细胞术的 支气管肺泡灌洗（BAL）细胞的表征，我们最近报道了一种新的鉴定， 哮喘的内源型，其特征在于气道中双阳性Th 2/Th 17细胞占优势。这 Th 2/Th 17优势内型将其自身与Th 2优势和Th 2/Th 17低内型区分开 更严重的哮喘和更难治的治疗，包括类固醇。的目的 建议研究严重难治性哮喘的Th 2/Th 17优势内型。我们提出4个具体的 目标。在具体目标1下，我们将表征哮喘患者气道中的双阳性Th 2/Th 17细胞 明确Th 2/Th 17优势型哮喘的表型。我们会进行支气管肺泡灌洗， 支气管内活检和刷检在难治性哮喘患者中的应用。我们将描述细胞因子的特征， 通过流式细胞术和RNA-seq.通过对组织的分析 组织病理学、肺生理学、免疫学和临床特征，我们将鉴定独特的表型 这些特征与Th 2/Th 17细胞产生Th 17细胞因子相关。具体目标2将 探讨哮喘气道Th 2/Th 17细胞的发生机制。我们将研究IL-1 β的作用 以及Th 2细胞转分化为Th 2/Th 17细胞中的CD 4-相关分子模式。下 具体目标3：阐明Th 2/Th 17细胞类固醇抵抗的信号转导机制。细胞因子 诱导Th 2/Th 17细胞也激活MEK和p38 MAPK信号通路。我们将研究 这些信号分子在诱导类固醇抗性中的作用。我们将研究MEK调节 糖皮质激素受体相关辅阻遏物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抗性的后果。具体目标4将审查 IL-1 α和IL-8在另一种类固醇抵抗型难治性哮喘--嗜中性粒细胞哮喘发病机制中的作用 哮喘我们还将研究Th 2细胞因子在防止中性粒细胞流入气道中的作用， Th 2/Th 17优势型哮喘。这项研究很重要，因为它确定和描述了一部小说 严重难治性哮喘的内型。我们将进行侵入性操作并检查支气管肺泡 灌洗液细胞和支气管组织用于绝大多数实验，这与哮喘直接相关。的 阐明Th 2/Th 17细胞发育及其类固醇抗性的分子机制将为研究Th 2/Th 17细胞的免疫调节机制奠定基础。 Th 2/Th 17内型重症难治性哮喘的现有治疗药物的临床试验的方式。

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.