Sprouty-2 Regulation of Signaling in Asthma

Sprouty-2 哮喘信号传导的调节

• 批准号: 8892055
• 负责人: Rafeul Alam
• 金额: $ 39.63万
• 依托单位: NATIONAL JEWISH HEALTH
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-15 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8892055
• 关键词: Abbreviations; Address; Affect; Allergens; Asthma; CD28 gene; CD3 Antigens; CD4 Positive T Lymphocytes; Cell Differentiation process; Cell Proliferation; Cells; Chronic; Chronic Disease; Clinical; Defect; Development; Disease; Down-Regulation; Endocytosis; Epithelial Cells; Extrinsic asthma; Feedback; Health; Human; Impairment; In Vitro; Inflammation; Inflammatory; Knock-out; Knockout Mice; Knowledge; Ligands; MAPK3 gene; Maintenance; Mediating; Modeling; Mus; Outcome; Output; Patients; Phenotype; Play; Public Health; Recycling; Regulation; Reporting; Resolution; Role; Signal Pathway; Signal Transduction; Signaling Molecule; T-Lymphocyte; Testing; Th2 Cells; Tissues; Up-Regulation; airway hyperresponsiveness; airway inflammation; anergy; asthmatic patient; base; cell motility; cytokine; in vivo; mouse model; new therapeutic target; novel; prevent; receptor; response; signal processing; ubiquitin ligase

DESCRIPTION (provided by applicant): Asthma is a chronic inflammatory disease of the airways where T cells manifest a biased Th2/Th17 differentiation and a hyperactive phenotype. The latter is associated with sustained intracellular signaling. Signaling processes are usually transient due to negative homeostatic regulation. There is a knowledge gap in our understanding of mechanisms that induce sustained signaling. We propose to delineate the mechanism of induction of sustained signaling in T cells from asthma. We have reported that the signaling molecule sprouty 2 (spry 2) plays an essential role in establishing a self-sustained signaling mechanism for ERK1/2. To address this further we have generated CD4 targeted spry 2 knockout mice. Spry2-/- T cells have increased Cbl-b and decreased Nedd4. The foregoing ubiquitin ligases antagonistically regulate TCR ubiquitylation, endocytosis, degradation and thereby, control TCR signaling output. As a consequence of these receptor proximal abnormalities spry2-/-T cells have impaired signaling and proliferation. These impairments become more pronounced following CD28 engagement. Spry2-/- T cells have impaired Th2/Th17 differentiation. They are unable to mount airway inflammation, hyperreactivity and remodeling in a mouse model of asthma. Based upon these preliminary results we hypothesize that spry 2 amplifies and prolongs T cell signaling by forming a tripartite regulatory network where spry 2 and Nedd4 antagonize the signal terminating action of Cbl-b. Spry2- driven amplification and sustenance of signaling is important for co-stimulation, Th2/Th17 differentiation and development of asthma. Under specific aim 1 we will examine the role of spry 2 in generating sustained signaling in T cells. We will define the scope of CD3- and especially CD28-induced signaling pathways that are regulated by spry 2. We will examine the contribution of Cbl-b and Nedd4 to the spry2 knockout phenotype. Specific aim 2 will study the importance of spry 2 for Th2 and Th17 cell differentiation in vitro and in vivo in spry2-/- mice. We will delineae the signaling mechanism by which spry 2 regulates Th2/Th17 differentiation. Under specific aim 3 we will delineate the role of spry 2 in inducing and sustaining inflammation in a mouse model of chronic asthma. We will examine if Cbl-b knockout reverses the spry2 knockout phenotype. Under specific aim 4 we will study the expression of spry 2 in CD4 T cells from asthmatic patients and examine its contribution to the hyperactive T cell phenotype and biased differentiation in asthma. These studies are important because they have uncovered a hitherto unknown regulatory network involving spry2, Cbl-b and Nedd4, which controls Th2/Th17 differentiation and development of asthma.

描述（由申请人提供）：哮喘是一种慢性气道炎症性疾病，其中 T 细胞表现出偏向的 Th2/Th17 分化和过度活跃的表型。后者与持续的细胞内信号传导有关。由于负稳态调节，信号传导过程通常是短暂的。我们对诱导持续信号传导的机制的理解存在知识差距。我们建议描述哮喘 T 细胞持续信号传导的诱导机制。我们报道了信号分子 sprouty 2 (spry 2) 在建立 ERK1/2 自我维持信号传导机制中发挥着重要作用。为了进一步解决这个问题，我们生成了 CD4 靶向 spry 2 基因敲除小鼠。 Spry2-/- T 细胞增加了 Cbl-b 并减少了 Nedd4。上述泛素连接酶拮抗地调节TCR泛素化、内吞作用、降解，从而控制TCR信号输出。由于这些受体近端异常，spry2-/-T 细胞的信号传导和增殖受损。 CD28 参与后这些损伤变得更加明显。 Spry2-/- T 细胞的 Th2/Th17 分化受损。他们无法在哮喘小鼠模型中建立气道炎症、高反应性和重塑。基于这些初步结果，我们假设 spry 2 通过形成三方调节网络来放大和延长 T 细胞信号传导，其中 spry 2 和 Nedd4 拮抗 Cbl-b 的信号终止作用。 Spry2 驱动的信号放大和维持对于共刺激、Th2/Th17 分化和哮喘的发展很重要。在具体目标 1 下，我们将研究 spry 2 在 T 细胞中产生持续信号传导的作用。我们将定义由 spry 2 调节的 CD3 诱导的信号通路（尤其是 CD28 诱导的信号通路）的范围。我们将检查 Cbl-b 和 Nedd4 对 spry2 敲除表型的贡献。具体目标 2 将研究 spry2-/- 小鼠体外和体内 spry 2 对 Th2 和 Th17 细胞分化的重要性。我们将描述 spry 2 调节 Th2/Th17 分化的信号机制。在具体目标 3 下，我们将描述 spry 2 在慢性哮喘小鼠模型中诱导和维持炎症的作用。我们将检查 Cbl-b 敲除是否会逆转 spry2 敲除表型。在具体目标 4 下，我们将研究哮喘患者 CD4 T 细胞中 spry 2 的表达，并检查其对哮喘中过度活跃的 T 细胞表型和偏向分化的贡献。这些研究很重要，因为它们揭示了一个迄今为止未知的涉及 spry2、Cbl-b 和 Nedd4 的调控网络，该网络控制着 Th2/Th17 分化和哮喘的发展。