MOLECULAR STUDIES OF FC RECEPTORS FOR IMMUNOGLOBULIN E

肥大细胞和嗜碱性粒细胞上的IgE受体(Fcepsilone R-I)是 直接参与IgE介导的这些细胞的激活。 近年来，大鼠氟西隆α-亚基的编码基因 R-I(Fcepsilone R-Ipha)已被克隆。RNA的异质性是 随后检测到，表明存在Fc的变种 Epsilone R-Ipha，包括可能存在的细胞内 Fc-epsilone R-Ipha的形式和分泌截断形式。一种新的 Ige结合蛋白，epsilone BP，被发现含有有趣的 结构特征，但其功能尚待界定。在……里面 本次研究计划，我们将继续我们对两个RC的研究 Epsilone R-I和epsilone BP。 一、啮齿动物氟硅酮R-I的构效关系 阿尔法将会成立。克隆的cDNAs在哺乳动物中的表达 通过基因转染法进行细胞培养。两者的表达 受体的表面膜结合型和可溶性型 将会被追查。正常大鼠肥大组织中突变型Fc-epsilone R-Iα 细胞。从cDNA克隆中预测的各种蛋白质产物 结果，包括胞内和区段截断形式 将为结构功能生成Fcepsilone R-I Alphs 分析鉴定FcepsiloneR-Ialphs中的结构元素 参与与IgE的结合。 其次，将鉴定各种形式的FcepsiloneR-Ipha。 核糖核酸酶保护分析与聚合酶链式反应方法学 将被用来鉴定与以下相关的各种RNA形式 FcepsiloneR-Ipha在正常大鼠肥大细胞中的表达。各种蛋白质 从cDNA克隆结果预测的产物，包括 细胞内和分泌截短形式的FcepsiloneR-Ipha 将在RBL细胞中检测到。小鼠基因组DNA编码 FCepsiloneR-Ipha将被克隆并用于扩展上述 对鼠标系统进行分析。 第三，新发现的IgE结合蛋白的功能 (EpsiloneBP)将被划定。表达epsilone的细胞类型 并将确定epsilone在细胞中的位置。如果它 已确定epsilone不是细胞表面受体，其 作为一种可溶性蛋白，调节IgE或组胺的合成 本课程将探讨肥大细胞和嗜碱性粒细胞的释放。 本研究的长期目标是：1)建立 免疫球蛋白E关键成分的结构、功能及其调控 系统；以及2)治疗方法的发展 人类过敏性疾病。

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.