MECHANISM OF ACTION OF A HUMAN GRANULOPOIETIN--GM-CSF

粒细胞-巨噬细胞集落刺激因子（GM-CSF）刺激 正常骨髓造血细胞增殖和成熟 祖细胞GM-CSF目前用于改善 化疗和放疗引起的骨髓抑制， 骨髓移植后的恢复。 最近，GM-CSF 被用作“收获激素”，以动员祖细胞到 外周血 这些策略为癌症提供了强大的新工具 治疗，以及未来的基因治疗策略。 研究的目标是 本竞争性续约申请中描述的是继续我们的 人GM-CSF作用机制的研究。 基于进度 在过去的资助期内取得的成就，提出了三个具体目标： L.为了定义阿尔法函数所需的关键区域， GM-CSF受体的β亚单位。 这些研究采用定点 和GM-CSF α和β亚基的截短突变体 受体以识别配体结合所需的分子区域， 内化和信号转导。 此外， 表达非功能性但中等亲和力的神经嵴起源 受体将被用来表征α和β的结构， 在这些细胞中发现的亚基。 2.鉴定和表征所需的其他分子组分 GM-CSF受体的功能。 战略概述， 鉴定推定酪氨酸激酶和其它细胞内组分 它可以与α和β亚基相互作用， GM-CSF受体。 来自神经嵴组织的细胞系将被 用作生物学背景以引入额外的推定受体 产生高亲和力功能性GM-CSF受体所需的组分。 3. 采用早期反应基因诱导作为终点， 介导GM-CSF作用的生化途径。 我们将继续 研究以确定早期的启动子中的顺式作用DNA序列， 反应基因EGFR-1，其对GM-CSF有反应。 蛋白 与这些序列的相互作用将被识别和检查， 对GM-CSF应答的翻译修饰。

Granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulates the proliferation and maturation of normal bone marrow hematopoietic progenitor cells. GM-CSF is currently employed to ameliorate myelosuppression caused by chemotherapy and radiation and to facilitate recovery following bone marrow transplantation. More recently, GM-CSF has been employed as a "harvest hormone" to mobilize progenitor cells to the peripheral blood. These strategies provide powerful new tools in cancer therapy, and for future gene therapy strategies. The goal of the studies described in this competitive renewal application is to continue our studies on the mechanism of action of human GM-CSF. Based on the progress achieved over the past funding period, three Specific Aims are proposed: l. To define the critical regions required for function of the alpha and beta subunits of the GM-CSF receptor. These studies employ site-directed and truncation mutants of both the alpha and beta subunits of the GM-CSF receptor to identify regions of the molecules required for ligand binding, internalization and signal transduction. In addition, cell lines of neural crest origin which express non-functional but intermediate-affinity receptors will be utilized to characterize the structure of alpha and beta subunits found in these cells. 2. To identify and characterize additional molecular components necessary for the function of the GM-CSF receptor. Strategies are outlined to identify putative tyrosine kinases and other intracellular components which can interact with the alpha and beta subunits to generate functional GM-CSF receptor. Cell lines derived from neural crest tissues will be used as a biological background to introduce additional putative receptor components required to generate high-affinity functional GM-CSF receptors. 3. Employ early response gene induction as an endpoint to define biochemical pathways mediating GM-CSF action. We will continue our studies to identify cis-acting DNA sequences in the promoter of the early response gene, EGR-l, which are responsive to GM-CSF. Proteins interacting with these sequences will be identified and examined for post- translational modification in response to GM-CSF.