Allen J M, Seed B
Department of Molecular Biology, Massachusetts General Hospital, Boston 02114.
Science. 1989 Jan 20;243(4889):378-81. doi: 10.1126/science.2911749.
Human and murine mononuclear phagocytes express a high-affinity receptor for immunoglobulin G that plays a central role in macrophage antibody-dependent cellular cytotoxicity and clearance of immune complexes. The receptor (FcRI) may also be involved in CD4-independent infection of human macrophages by human immunodeficiency virus. This report describes the isolation of cDNA clones encoding the human FcRI by a ligand-mediated selection technique. Expression of the cDNAs in COS cells gave rise to immunoglobulin G binding of the expected affinity and subtype specificity. RNA blot analysis revealed expression of a 1.7-kilobase transcript in macrophages and in cells of the promonocytic cell line U937 induced with interferon-gamma. The extracellular region of FcRI consists of three immunoglobulin-like domains, two of which share homology with low-affinity receptor domains.
人和鼠单核吞噬细胞表达一种免疫球蛋白G的高亲和力受体，该受体在巨噬细胞抗体依赖性细胞毒性及免疫复合物清除中起核心作用。该受体（FcRI）也可能参与人类免疫缺陷病毒对人巨噬细胞的非CD4依赖性感染。本报告描述了通过配体介导的筛选技术分离编码人FcRI的cDNA克隆。cDNA在COS细胞中的表达产生了具有预期亲和力和亚型特异性的免疫球蛋白G结合。RNA印迹分析显示，在巨噬细胞以及用γ干扰素诱导的原单核细胞系U937细胞中存在1.7千碱基转录本的表达。FcRI的细胞外区域由三个免疫球蛋白样结构域组成，其中两个与低亲和力受体结构域具有同源性。
