Cytokine signal transduction in immune system

免疫系统中的细胞因子信号转导

• 批准号: 6987818
• 负责人: Hodaka Fujii
• 金额: $ 33.01万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-12-01 至 2007-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6987818
• 关键词: biological signal transduction; cell differentiation; cytokine receptors; flow cytometry; genetic library; immunity; interferon gamma; interferon inducers; interleukin 2; interleukin 3; isozymes; laboratory mouse; protein tyrosine kinase; pyruvate kinase; reporter genes; transcription factor

DESCRIPTION (provided by applicant): Signal transduction from type I and type II cytokine receptors plays important roles in development and function of cells regulating immune system. Although accumulating evidence suggests importance of Jak-Stat pathways in cytokine signal transduction, our earlier studies and other reports demonstrated that lymphocytes can differentiate and function even in the absence of the activation of Stat proteins, leading to a hypothesis that Stat-independent signaling pathways may play important roles in lymphocyte differentiation and function. However, the molecular nature of Stat-independent pathways is still elusive. The objective of the present research is to elucidate these elusive signaling pathways by using a novel expression cloning system, inducible translocation trap (ITT). ITT is based on translocation of a fusion protein consisting of LexA DNA-binding domain, transactivation domain of a strong transcriptional activator and a test molecule. LexA-mediated reporter gene expression is detected by flow cytometry. This system will be employed to analyze Stat-independent pathways in interferon gamma, as well as interleukin (IL)-2 and IL-3 signaling. The initial screening of cDNA library revealed that an isoform of pyruvate kinase (M2-PK), a key enzyme in glycolysis, translocates into the nucleus following IL-3 stimulation. In addition, it was found that the nuclear M2-PK plays an important role in cell proliferation. Molecular mechanisms of IL-3-induced nuclear translocation of M2-PK and enhancement of cell proliferation by the nuclear M2-PK will be analyzed by using molecular and cell biological techniques. Detailed information gained from the proposed experiments will be valuable for elucidation of molecular mechanisms of oncogenesis and autoimmune diseases caused by dysregulation of cytokine signaling.

描述（申请人提供）：I型和II型细胞因子受体的信号转导在调节免疫系统的细胞发育和功能中起重要作用。尽管越来越多的证据表明Jak-Stat通路在细胞因子信号转导中的重要性，但我们早期的研究和其他报告表明，即使在没有Stat蛋白激活的情况下，淋巴细胞也可以分化和发挥功能，这导致了Stat独立信号通路可能在淋巴细胞分化和功能中发挥重要作用的假设。然而，stat独立通路的分子性质仍然是难以捉摸的。本研究的目的是通过一种新的表达克隆系统，诱导性易位陷阱（ITT）来阐明这些难以捉摸的信号通路。ITT是基于由LexA dna结合域、强转录激活子的反激活域和测试分子组成的融合蛋白的易位。流式细胞术检测lexa介导的报告基因表达。该系统将用于分析干扰素γ的stat独立通路，以及白细胞介素(IL)-2和IL-3信号传导。cDNA文库的初步筛选表明，糖酵解的关键酶丙酮酸激酶（M2-PK）的一个异构体在IL-3刺激下易位到细胞核中。此外，我们还发现细胞核中的M2-PK在细胞增殖中起着重要的作用。利用分子生物学和细胞生物学技术分析il -3诱导M2-PK核易位和细胞核M2-PK促进细胞增殖的分子机制。从所提出的实验中获得的详细信息将有助于阐明由细胞因子信号失调引起的肿瘤发生和自身免疫性疾病的分子机制。