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。哮喘患者的一个亚组 产生类固醇抗药性，这成为一个主要的治疗挑战，并对 社会。了解类固醇耐药的机制很重要。哮喘是由2型糖尿病引起的 免疫反应。2型固有淋巴样细胞(ILC2s)是2型细胞因子的重要来源。二 上皮性细胞因子IL33和TSLP促进ILC2s的发育和功能。我们最近做了 报道称，与血液中的ILC2s相比，来自哮喘患者亚组的呼吸道ILC2s是类固醇 以TSLP(胸腺间质淋巴生成素)依赖的方式耐药。血液中的ILC2对类固醇产生抗药性 当暴露在TSLP而不是IL33时。我们已经发现了这种二分性效应的机制。类固醇 上调TSLP受体，但不上调IL33。通过上调受体类固醇水平降低 它们的激活阈值。类固醇仍然拮抗这些细胞中的许多炎症途径，但令人惊讶的是， 使直接干扰糖皮质激素受体抑制物形成的途径具体化 很复杂。因此，在类固醇存在的情况下，这些途径上调2型细胞因子的作用不会减弱， 这会导致类固醇耐药性。基于这些发现，我们假设类固醇的激活 激素化受体通过上调选择性信号通路诱导类固醇耐药 干扰糖皮质激素受体(GR)阻滞剂复合体的形成。我们提出了三个具体的测试目标 前述假设。在特定的目标1下，我们将研究TSLP诱导的分子机制 ILC2s的类固醇耐药性。我们将研究涉及MEK2-CBX7-PRC1， 在初步实验中发现，它阻碍了GR抑制物复合体的组织。我们将使用 人类血液和肺ILC2与维持人类疾病的相关性。具体目标2致力于机械论 以及在老鼠身上进行的临床前研究。我们将研究反复接触过敏原和鼻病毒是如何 有助于类固醇抗药性的发展。我们将使用转基因小鼠来验证 类固醇耐药途径的重要性。我们将用途径抑制剂进行临床前试验 类固醇抵抗型哮喘人源化小鼠模型。在具体目标3下，我们将确定 TSLP和TSLPR信号分子在激素抵抗中的作用 来自激素抵抗和激素敏感哮喘患者的细胞。我们将对途径抑制剂进行评估 逆转呼吸道淋巴样细胞对类固醇的耐药性。我们拥有所有必要的专业知识、资源和 完成此项目的合作者。这项提案很重要，因为它解决了一个悬而未决的临床问题 不仅影响哮喘，而且还影响许多慢性炎症、自身免疫和肿瘤的问题 类固醇耐药性是治疗挑战的疾病。这个项目的成功完成将会有所帮助。 开发针对类固醇耐药的新治疗方法。

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.