Steroid resistance of airway ILC2s

摘要： 糖皮质激素类类固醇是哮喘治疗的主要药物。哮喘患者亚组 产生类固醇抗性，这成为主要的治疗挑战，并给患者带来高成本。 社会了解类固醇耐药的机制是重要的。哮喘是由2型 免疫反应2型先天淋巴样细胞（ILC2）是2型细胞因子的重要来源。两 上皮细胞因子-IL 33和TSLP促进ILC2的发育和功能。我们最近 报道，与血液ILC2相比，来自哮喘患者亚组的气道ILC2是类固醇 以TSLP（胸腺基质淋巴细胞生成素）依赖性方式抵抗。血液ILC2成为类固醇耐药 当暴露于TSLP而不是IL 33时。我们已经发现了这种二分效应的机制。类固醇 上调（活化）TSLP的受体，但不上调IL 33。通过上调受体类固醇降低 激活阈值。类固醇仍然拮抗这些细胞中的许多炎症通路，但令人惊讶的是， 使直接干扰糖皮质激素受体阻遏物形成的途径活跃 复杂.因此，这些途径上调2型细胞因子在类固醇存在下不减弱， 导致类固醇抵抗。基于这些发现，我们假设类固醇的激活 活化的受体通过上调选择的信号传导途径诱导类固醇抗性， 破坏糖皮质激素受体（GR）阻遏物复合物的形成。我们提出了3个具体的目标来测试 上述假设。在具体目标1下，我们将研究TSLP诱导的细胞凋亡的分子机制。 ILC2的类固醇抗性。我们将研究一种涉及MEK 2-CBX 7-PRC 1的新型信号通路， 在初步实验中鉴定，阻碍GR阻遏物复合物的组织。我们将使用 人血液和肺ILC2以维持人类疾病相关性。具体目标2致力于机械化 和小鼠的临床前研究。我们将研究如何重复暴露于过敏原和鼻病毒 有助于类固醇耐药性的发展。我们将使用转基因小鼠来验证 类固醇耐药途径的重要性。我们将进行临床前试验与途径抑制剂在一个 类固醇抵抗性哮喘的人源化小鼠模型。在具体目标3下，我们将确定以下方面的相关性： 通过研究支气管肺泡灌洗液ILC和T细胞研究激素抵抗的TSLP和TSLPR信号分子 来自类固醇抗性和类固醇敏感性哮喘患者的细胞。我们将评估通路抑制剂， 逆转气道淋巴细胞的类固醇抵抗。我们拥有所有必要的专业知识、资源和 合作者来完成这个项目。该提案很重要，因为它解决了一个悬而未决的临床问题。 这个问题不仅影响哮喘，而且影响许多慢性炎症，自身免疫和肿瘤 类固醇耐药性是治疗挑战的疾病。这个项目的成功完成将有助于 开发针对类固醇耐药性的新型治疗方法。

Abstract: The glucocorticoid-type steroids are the mainstay of asthma therapy. A subgroup of asthmatic patients develops steroid resistance, which becomes a major therapeutic challenge and imposes a high cost to the society. An understanding the mechanism of steroid resistance is important. Asthma is driven by the type 2 immune response. Type 2 innate lymphoid cells (ILC2s) are an important source of type 2 cytokines. Two epithelial cytokines—IL33 and TSLP promote the development and function of ILC2s. We have recently reported that airway ILC2s, as compared to blood ILC2s, from a subgroup of asthmatic patients are steroid resistant in a TSLP (thymic stromal lymphopoietin)-dependent manner. Blood ILC2s become steroid resistant when exposed to TSLP but not IL33. We have uncovered a mechanism for this dichotomous effect. Steroids upregulate (protagonize) the receptors for TSLP but not IL33. By upregulating the receptors steroids lower their activation threshold. Steroids still antagonize many inflammatory pathways in these cells but, surprisingly, protagonize the pathways that directly interfere with the formation of the glucocorticoid receptor repressor complex. Consequently, these pathways upregulate type 2 cytokines unabated in the presence of steroids, which results in steroid resistance. Based upon these findings we hypothesize that activation of steroid protagonized receptors induces steroid resistance through upregulation of select signaling pathways that disrupt the formation of the glucocorticoid receptor (GR) repressor complex. We propose 3 specific aims to test the foregoing hypothesis. Under specific aim 1 we will study the molecular mechanism of TSLP-induced steroid resistance of ILC2s. We will examine how a novel signaling pathway involving MEK2-CBX7-PRC1, identified in preliminary experiments, hinders the organization of the GR repressor complex. We will use human blood and lung ILC2s to maintain human disease relevance. Specific aim 2 is devoted to mechanistic and preclinical studies in mice. We will examine how repetitive exposure to allergens and rhinovirus contributes to the development of steroid resistance. We will use genetically modified mice to validate the importance of steroid resistant pathways. We will perform preclinical trials with pathway inhibitors in a humanized mouse model of steroid resistant asthma. Under specific aim 3 we will establish the relevance of TSLP and TSLPR signaling molecules for steroid resistance by studying bronchoalveolar lavage ILCs and T cells from steroid resistant and steroid sensitive asthmatic patients. We will evaluate pathway inhibitors for reversal of steroid resistance of airway lymphoid cells. We have all the necessary expertise, resources and collaborators to accomplish this project. The proposal is important because it addresses an unresolved clinical problem that affects not only asthma but also many chronic inflammatory, autoimmune and neoplastic diseases where steroid resistance is a therapeutic challenge. A successful completion of this project will help develop novel therapeutic modalities targeting steroid resistance, in general.