Biology and regulation of Il-13 receptor alpha 2

描述(申请人提供)：哮喘是最常见的住院指征，也是最常见的儿童慢性病。在动物模型中，IL-13在哮喘和过敏性炎症的发生发展中起关键作用。我们已经在我们的初步数据中证明了IL-13Rα2是一种细胞内分子，其激活依赖的表面表达抑制了IL-13信号转导。这项建议描述了一项为期5年的指导培训计划，旨在发展基础科学研究的学术生涯。该提案将研究IL-13Rα2的表面表达调节、亚细胞定位、IL-13信号抑制的机制以及相关的关键结构基序。我们将研究广泛的调节细胞因子在调节其表面表达中的作用。亚细胞定位将通过共聚焦显微镜检查与已知的亚细胞隔间的共定位来研究。通过建立转基因模型，可以研究该受体过度表达的影响。我们已经建立了一个缺乏竞争的内源性IL-13受体的IL-13信号的体外模型。我们将研究IL-13在这些细胞中的依赖信号。我们将产生表达越来越多的IL-13Rα2的细胞，并确定是否存在这种分子表达增加的剂量反应。该模型还将用于确定哪些结构元件对IL-13Rα2调节IL-13信号重要。将产生IL-13Rα2突变体，截断蛋白质以删除细胞质区域，突变细胞质酪氨酸，或突变已被证明影响受体内化的三亮氨酸区域。我们将研究这些突变体与野生型IL-13Rα2相比的蛋白质稳定性、IL-13结合亲和力、表面表达以及对调节IL-13信号的影响。这一新的转染模型将确定IL-13Rα2中允许抑制IL-13信号的关键结构元件。这项应用代表了对IL-13Rα2细胞因子依赖的表面表达、其在调节IL-13信号中的作用以及所涉及的IL-13Rα2的结构元素的首次广泛研究。

DESCRIPTION (provided by applicant): Asthma is the most common indication for hospitalization and is the most common chronic disease of childhood. In animal models, IL-13 plays a key role in the development of asthma and allergic inflammation. We have demonstrated in our preliminary data that IL-13R alpha 2 is an intracellular molecule and its activation-dependent surface expression inhibits IL-13 signaling. This proposal describes a 5-year mentored training program for the development of an academic career in basic science research. The proposal will investigate surface expression regulation, subcellular localization, the mechanism of IL-13 signal suppression, and the related key structural motifs of IL-13R alpha 2. We will examine the role of a broad panel of regulatory cytokines in modulating its surface expression. Subcellular localization will be studied by confocal microscopy examining colocalization with known subcellular compartments. Transfection models will allow study of the effect of overexpression of this receptor. We have generated an in vitro model of IL-13 signaling that lacks competing endogenous IL-13 receptors. We will study IL-13 dependent signaling in these cells. We will generate cells expressing increasing amounts of IL-13R alpha 2 and determine if there is a dose-response of increasing expression of this molecule. This model will also be used to determine what structural elements are important to IL-13R alpha 2 modulating IL-13 signaling. IL-13R alpha 2 mutants will be created, truncating the protein to delete the cytoplasmic region, mutating the cytoplasmic tyrosine, or mutating the tri-leucine region that has been demonstrated to affect receptor internalization. We will study protein stability, IL-13 binding affinity, surface expression, and the effect on modulating IL-13 signaling in these mutants compared to wild type IL-13R alpha 2. This novel transfection model will determine the key structural elements in the IL-13R alpha 2 that allow inhibition of IL-13 signaling. This application represents the first extensive study of IL-13R alpha 2 cytokine dependent surface expression, its role in modulating IL-13 signaling, and the structural elements of IL-13R alpha 2 that are involved.