Regulation of T cell-derived cytokines in allergic airway inflammation

T 细胞衍生细胞因子在过敏性气道炎症中的调节

• 批准号: 10410348
• 负责人: Jennifer S Chen
• 金额: $ 3.08万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-01 至 2023-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10410348
• 关键词: 3' Untranslated Regions; Affect; Affinity; Allergens; Allergic Disease; Alternaria; Antibodies; Antibody Affinity; Asthma; B-Lymphocytes; Basophils; Binding; Binding Sites; Cell Survival; Complementary DNA; Data; Development; Disease; Event; Extrinsic asthma; Genetic Transcription; Helper-Inducer T-Lymphocyte; HuR protein; IgE; Immune response; Immunization; Immunoglobulin Class Switching; Immunologics; Immunoprecipitation; Inflammation; Interleukin-4; Internal Ribosome Entry Site; Length; Lipopolysaccharides; Lung Inflammation; Maps; Mediating; Mediator of activation protein; Messenger RNA; Modeling; Molecular; Mus; Mutate; Mutation; Pathogenesis; Pathogenicity; Patients; Play; Population; Post-Transcriptional Regulation; Prevalence; Production; Protein Isoforms; Proteins; Public Health; RNA-Binding Proteins; Regulation; Reporter; Role; Signal Transduction; Source; Structure of germinal center of lymph node; Surface; T cell regulation; T-Lymphocyte; Th2 Cells; Training; Transcript; Translations; airborne allergen; allergic airway disease; allergic airway inflammation; anti-IgE; asthma exacerbation; chemical release; crosslink; cytokine; improved; insight; mRNA Expression; mRNA Stability; mast cell; microbial; mouse model; prevent; response; targeted treatment; therapeutically effective

Project Summary The increasing prevalence of asthma over the past few decades signals an urgent need to understand disease pathogenesis and to develop more effective therapeutics. High affinity IgE plays a central role in the disease by mediating mast cell and basophil degranulation, which releases chemical mediators responsible for asthma exacerbation. T follicular helper (Tfh) cells promote the relevant high affinity antibodies for a given immune response through the cytokines they secrete. Tfh cell-derived IL-4 is required to induce high affinity IgE in response to allergens. However, IL-4 has also been considered a canonical Tfh cell cytokine, produced even during microbial immunizations that do not elicit IgE. Such studies largely rely on the use of an IL-4 cytokine reporter that indicates activation of Il4 transcription but not necessarily transcript stability or translation. Our lab has established murine models of Alternaria-induced allergic airway inflammation (AAI), which involves high affinity IgE production, as well as lipopolysaccharide (LPS)-induced lung inflammation, which does not. Using these two models, I observed Il4 mRNA expression in Tfh cells from both conditions; in contrast, I found that only Tfh cells in AAI produce IL-4 protein. My preliminary data suggest that Il4 mRNA in Tfh cells from AAI is more stable than that from LPS-induced inflammation, uncovering a post-transcriptional regulatory mechanism that governs IL-4 production in Tfh cells. My overall hypothesis is that post-transcriptional regulation of Il4 is a checkpoint dictating the high affinity IgE-promoting capacity of Tfh cells. My proposal therefore suggests a new paradigm for the regulation of IL-4 protein production in Tfh cells and the molecular basis of IgE-mediated AAI. My first aim is to identify the mRNA regulatory sequences responsible for Il4 post-transcriptional regulation in Tfh cells during AAI versus LPS-induced lung inflammation. To accomplish this, I will clone Il4 expression constructs mutated in regulatory sequences to determine the effect on Il4 mRNA stability, IL-4 protein production, and high affinity IgE responses. My second aim is to evaluate the role of an RNA-binding protein (RBP) on IL-4 production in Tfh cells during AAI. To do this, I will map RBP-Il4 binding sites, mutate these binding sites in Il4 expression constructs, and evaluate the effect of such mutations on Il4 mRNA stability, IL-4 protein production, and high affinity IgE responses. If successful, this project will define a previously undescribed mechanism of IgE regulation in asthma while also elucidating the immunologic rules that prevent the inappropriate induction of IgE in non-allergic responses. Such findings will offer valuable insight into new strategies for blocking IgE development in asthma and other allergic diseases.

项目摘要 在过去的几十年中，哮喘的患病率不断增加，这表明迫切需要了解疾病 发病机理并开发更有效的治疗剂。高亲和力IgE在疾病中起着核心作用 介导肥大细胞和嗜嗜碱性脱粒，释放负责哮喘的化学介质 恶化。 T卵泡辅助器（TFH）细胞促进给定免疫的相关高亲和力抗体 他们分泌的细胞因子反应。需要TFH细胞衍生的IL-4才能诱导高亲和力IgE 对过敏原的反应。但是，IL-4也被认为是典型的TFH细胞因子，甚至会产生 在不引起IgE的微生物免疫接种期间。这样的研究在很大程度上依赖于IL-4细胞因子的使用 指示激活IL4转录但不一定是转录本稳定性或翻译的记者。我们的实验室 已经建立了替代诱导的过敏气道炎症（AAI）的鼠模型，涉及高 亲和力IgE产生以及脂多糖（LPS）诱导的肺部炎症，但没有。使用 我从两种情况下观察到这两个模型在TFH细胞中观察到IL4 mRNA的表达。相反，我发现 AAI中只有TFH细胞产生IL-4蛋白。我的初步数据表明，来自AAI的TFH细胞中的IL4 mRNA是 比LPS引起的炎症更稳定，揭示了转录后调节机制 控制TFH细胞中IL-4的产生。我的总体假设是，IL4的转录后调节是 检查点决定了TFH细胞的高亲和力IgE促进能力。因此，我的建议暗示了一个新的 调节TFH细胞中IL-4蛋白产生的范例和IgE介导的AAI的分子基础。 我的第一个目的是确定负责IL4后转录后的mRNA调节序列 AAI与LPS诱导的肺部炎症期间TFH细胞的调节。为此，我会克隆 IL4表达构建在调节序列中突变，以确定对IL4 mRNA稳定性的影响，IL-4 蛋白质产生和高亲和力IgE反应。我的第二个目的是评估RNA结合的作用 AAI期间TFH细胞中IL-4产生的蛋白质（RBP）。为此，我将映射RBP-IL4结合位点，突变 IL4表达构建体中的这些结合位点，并评估此类突变对IL4 mRNA稳定性的影响， IL-4蛋白质产生和高亲和力IgE反应。如果成功，该项目将定义以前的 哮喘中IgE调节的未描述的机制，同时还阐明了防止免疫学规则 非过敏性反应中IgE的不当诱导。这样的发现将为新的洞察力提供宝贵的见解 阻止哮喘和其他过敏性疾病中IGE发展的策略。