MOLECULAR STUDIES OF FC RECEPTORS FOR IMMUNOGLOBULIN E

免疫球蛋白 E FC 受体的分子研究

• 批准号: 2061010
• 负责人: FU-TONG LIU
• 金额: $ 22.34万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-08-01 至 1995-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2061010
• 关键词: RNase protection assay; antibody formation; antibody receptor; basophils; binding proteins; chemical structure function; gene expression; genetic manipulation; genetic recombination; histamine release; hypersensitivity; immunoglobulin E; immunoregulation; laboratory mouse; laboratory rabbit; mast cell; membrane proteins; messenger RNA; molecular cloning; protein structure; site directed mutagenesis; tissue /cell culture; transfection

The IgE receptor on mast cells and basophils (Fcepsilone R-I) is directly involved in the IgE-mediated activation of these cells. Recently, cDNA coding for the alpha-subunit of the rat Fcepsilone R-I (Fcepsilone R-Ialpha) has been cloned. RNA heterogeneity was subsequently detected, suggesting the presence of variants of Fc epsilone R-Ialpha, including the possible presence of intracellular forms and secretory truncated forms of Fc epsilone R-Ialpha. A new IgE-binding protein, epsilone BP, was found to contain interesting structural features, but its function is yet to be defined. In this research program, we will continue our studies of both Rc epsilone R-I and epsilone BP. First, structure-function relationship of rodent Fcepsilone R-I alpha will be established. Expression of cloned cDNA in mammalian cells by gene transfection will be conducted. Expression of both the surface membrane-bound form and soluble form of the receptor will be pursued. Mutant Fc epsilone R-I alpha in normal rat mast cells. Various protein products predicted from the cDNA cloning results, including the intracellular and secetory truncated forms of Fcepsilone R-I alphs will be generated for structure-function analysis to identify structural elements in FcepsiloneR-Ialphs that are involved in binding to IgE. Second, various forms of FcepsiloneR-Ialpha will be identified. RNase protection analysis and polymerase chain reaction methodology will be employed to identify various RNA forms related to FcepsiloneR-Ialpha in normal rat mast cells. Various protein products predicted from the cDNA cloning results, including the intracellular and secretory truncated forms of FcepsiloneR-Ialpha will be detected in RBL cells. Genomic DNA coding for mouse FCepsiloneR-Ialpha will be cloned and used to extend the above analysis to the mouse system. Third, function of the newly defiend IgE-binding protein (epsiloneBP) will be delineated. Cell types expressing epsilone and the location of epsilone in cells will be identified. If it is established that epsilone is not a cell suface receptor, its role as a soluble protein, regulating IgE synthesis or histamine release form mast cells and basophils will be explored. The long-term goals of this research are: 1) establishment of structure, function and regulation of key components of the IgE system; and 2) development of therapeutic methods for the treatment of human allergic disorders.

肥大细胞和嗜碱性粒细胞（fcepsilone r-i）上的IgE受体是 直接参与了这些细胞的IgE介导的激活。 最近，编码大鼠fcepsilone的α-亚基的cDNA R-I（fcepsilone r-ialpha）已克隆。 RNA异质性是 随后检测到，表明存在FC的变体 Epsilone r-ialpha，包括可能存在细胞内 FC Epsilone r-ialpha的形式和分泌截断形式。 一个新 发现IgE结合蛋白Epsilone BP包含有趣的 结构特征，但其功能尚未定义。 在 该研究计划，我们将继续研究两个RC Epsilone R-I和Epsilone BP。 首先，啮齿动物Fcepsilone R-I的结构功能关系 将建立Alpha。 克隆cDNA在哺乳动物中的表达 将通过基因转染进行细胞。 两者的表达 受体的表面膜结合形式和可溶性形式 将被追捕。 正常大鼠桅杆中的突变FC Epsilone R-Iα 细胞。 通过cDNA克隆预测的各种蛋白质产物 结果，包括细胞内和截断形式 将生成fcepsilone r-i alphs的结构功能 分析以识别fcepsiloner-ialphs中的结构元素 参与与IgE结合。 其次，将确定各种形式的fcepsiloner-ialpha。 RNase保护分析和聚合酶链反应方法 将使用与 正常大鼠肥大细胞中的fcepsiloner-ialpha。 各种蛋白质 cDNA克隆结果预测的产品，包括 fcepsiloner-ialpha的细胞内和分泌截断形式 将在RBL细胞中检测到。 小鼠编码的基因组DNA Fcepsiloner-ialpha将被克隆并用来扩展上述 分析鼠标系统。 第三，新的Defiend IgE结合蛋白的功能 （EpsiloneBP）将被描述。 表达Epsilone的细胞类型 并且将鉴定出Epsilone在细胞中的位置。 如果是 确定epsilone不是细胞suface受体，而是 作为可溶性蛋白的作用，调节IgE合成或组胺 将探索释放形式的肥大细胞和嗜碱性细胞。 这项研究的长期目标是：1）建立 IgE关键组成部分的结构，功能和调节 系统; 2）开发治疗方法 人类过敏性疾病。