DERIVATION OF MODEL SYSTEMS FOR HEMATOPOIETIC GROWTH FACTOR RECEPTOR FUNCTION

造血生长因子受体功能模型系统的推导

• 批准号: 6239205
• 负责人: BERNARD MATHEY-PREVOT
• 金额: $ 12.97万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-05 至 1998-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6239205
• 关键词: PC12 cells; biological models; biological signal transduction; cell differentiation; cell type; chimeric proteins; embryonic stem cell; erythropoietin; gene induction /repression; gene mutation; growth factor receptors; hematopoiesis; hematopoietic growth factor; interleukin 3; laboratory mouse; laboratory rabbit; model design /development; northern blottings; phosphorylation; protein structure function; tissue /cell culture

Hematopoietic growth factor (HGF) receptors are the first link in the relay of signals that culminate in proliferation or differentiation of a progenitor hematopoietic cell. Recent advances in signal transduction suggest that the majority of receptors interact with overlapping sets of secondary effectors inside the cell. It is therefore remarkable that seemingly opposite responses -proliferation and differentiation- can be signaled through shared effector proteins, and that specificity in response to a given HGF can be maintained. How this is achieved is unknown. Two model systems will be developed to address these questions. In the first model, the rat pheochromocytoma cell line PC12 will be used to study the function of the mouse interleukin-3 receptor (IL-3R). Preliminary data suggest that introduction of the IL-3R components into PC12 cells, and stimulation with IL-3 leads to neuronal differentiation. Thus, structure-function relationship of the IL-3R and the role of other HGF and HGF chimeric receptors can be assessed in the absence of interfering endogenous receptors, and in the context of differentiation rather than proliferation. Chimeric receptors have been used to define critical regions in HCF receptors mediating specificity in the differentiation response. For instance, an EPO-R/betaIL-3R chimeric receptor can induce limited differentiation of a progenitor cell line, even though it lacks the cytoplasmic region of the EPO-R. One potential caveat in these experiments is the fact that the indicator cell line is only permissive to limited differentiation, and may already be precommitted to a given lineage. Thus, the observed differentiation may not reflect a physiological response. To circumvent this limitation and address the question of specificity, embryonic stem (ES) cell clones will be obtained in which the wild-type erythropoietin (EPO) receptor has been replaced by an EPO-R/betaIL-3R chimeric receptor. The contribution of this chimeric receptor to blood formation and more specifically to erythropoiesis will be monitored in vivo in mice homozygous for the chimeric receptor, and, in vitro, in colony assay with progenitor cells derived from embryoid bodies. These two model systems described above represent a novel approach to assay HGF-R function, and complement or improve existing models that rely primarily on proliferation.

造血生长因子（HGF）受体是第一个联系 信号的继电器在增殖或分化中达到顶点 祖细胞造血细胞。信号转导的最新进展 建议大多数受体与重叠集相互作用 细胞内的次要效应子。因此，非常了不起 看似相反的反应 - 增殖和差异化可能是 通过共享效应子蛋白发出信号，并在 可以维持对给定的HGF的响应。这是如何实现的 未知。将开发两个模型系统来解决这些问题。 在第一个模型中，将使用大鼠嗜铬细胞瘤细胞系PC12 研究小鼠白介素3受体（IL-3R）的功能。 初步数据表明，将IL-3R组件引入 PC12细胞和IL-3刺激导致神经元分化。 因此，IL-3R的结构功能关系与其他的作用 HGF和HGF嵌合受体可以在没有的情况下进行评估 干扰内源性受体，并在分化的背景下 而不是扩散。嵌合受体已用于定义 HCF受体中介导特异性的关键区域 分化响应。例如，epo-r/betail-3r嵌合 受体可以诱导祖细胞系的有限分化， 即使它缺乏EPO-R的细胞质区域。一个潜力 这些实验中的注意事实是指标细胞系是 仅允许差异化，并且可能已经是 预先提交给给定的血统。因此，观察到的分化可能 不反映生理反应。避免这种限制和 解决特异性问题，胚胎茎（ES）细胞克隆将 可以获得野生型红细胞生成素（EPO）受体已成为 由EPO-R/Betail-3R嵌合受体取代。这个贡献 嵌合受体形成血液，更具体地 红细胞生成的小鼠将在体内监测纯合的小鼠 嵌合受体，并在体外与祖细胞的菌落测定法 源自胚胎体。上面描述的这两个模型系统 代表一种新颖的方法来测定HGF-R功能，并补充或 改善主要依赖于增殖的现有模型。