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）受体是造血干细胞的第一个环节。 信号的传递，最终导致细胞的增殖或分化， 造血祖细胞信号转导研究进展 表明大多数受体与重叠的 细胞内的次级效应器。因此，值得注意的是， 看似相反的反应-增殖和分化-可以是 通过共享的效应蛋白发出信号， 可以维持对给定HGF的应答。如何做到这一点是 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PC 12 目的：研究小鼠白细胞介素3受体（IL-3R）的功能。 初步数据表明，将IL-3 R成分引入 PC 12细胞，并且用IL-3刺激导致神经元分化。 因此，IL-3R的结构-功能关系和其他调节因子的作用可能与IL-3受体的结构和功能有关。 HGF和HGF嵌合受体可以在不存在HGF的情况下评估。 干扰内源性受体，并在分化的背景下， 而不是扩散。嵌合受体已被用于定义 HCF受体中介导特异性的关键区域 分化反应。例如，EPO-R/β IL-3R嵌合体 受体可以诱导祖细胞系的有限分化， 尽管它缺少EPO-R的胞质区域。一个潜在 这些实验中的警告是指示细胞系是 仅允许有限的分化，并且可能已经 预先确定的血统。因此，观察到的分化可能 不是生理反应为了规避这一限制， 为了解决特异性问题，胚胎干细胞克隆将 其中野生型促红细胞生成素（EPO）受体已被 被EPO-R/β IL-3R嵌合受体取代。这一贡献 嵌合受体，更具体地说， 红细胞生成将在体内在对于所述抗体纯合的小鼠中进行监测。 嵌合受体，并在体外用祖细胞进行集落测定 源自胚状体。上述两个模型系统 代表了一种新的方法来测定HGF-R功能，并补充或 改进主要依赖扩散的现有模式。