Binding of monomeric immunoglobulins to Fc receptors of mouse macrophages.
Binding of monomeric immunoglobulins to Fc receptors of mouse macrophages.
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DOI：
10.1084/jem.142.6.1520
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发表时间：
1975-12-01
影响因子：
15.3
通讯作者：
Eisen, H N
中科院分区：
文献类型：
--
作者：
Unkeless, J C;Eisen, H N
用小鼠骨髓瘤蛋白和正常腹腔巨噬细胞、巯基乙酸盐刺激的巨噬细胞和巨噬细胞系P388 D1研究了小鼠巨噬细胞上免疫球蛋白表面受体的结合特性。小鼠胚胎成纤维细胞的原代培养物作为对照。IgG 2a蛋白结合强烈; IgG 2b结合较弱（IgG 2a的二十分之一）;IgM、伊加和IgG 1未显著结合。巯基乙酸盐刺激的细胞中，每个细胞的IgG 2a结合位点数为4 × 10（5），正常细胞和P388 D1细胞中为1 × 10（5）。结合表现为：随着温度的降低，平衡（缔合）常数增加，解离速率常数降低（在37 ℃时，相应的值为2 × 10（7）M-1和0.26 min-1，后者的值对应于解离的半衰期为2.6 min）。从缔合和解离的快速性来看，似乎巨噬细胞的表面与细胞的直接微环境中的IgG 2a分子处于动态平衡。IgG 2a的受体对免疫球蛋白恒定结构域中的决定簇具有明确的特异性：两种等电点差异很大的IgG 2a蛋白（通过等电聚焦测定）以相同的亲和力与相同的受体结合;此外，Fc片段结合而Fab片段不结合。IgG 2a蛋白的Fc受体通过将巨噬细胞短暂暴露于胰蛋白酶而容易地消除。受体在随后的无血清培养基培养过程中再生，再生被放线菌酮完全抑制，部分被放线菌素D抑制。
The binding properties of surface receptors of immunoglobulins on mouse macrophages were studied with mouse myeloma proteins and normal peritoneal macrophages, thioglycollate-stimulated macrophages, and a macrophage cell line, P388D1. Primary cultures of mouse embryo fibroblasts served as controls. IgG2a proteins were bound strongly;IgG2b was bound weakly (one-twentieth as well as IgG2a);IgM, IgA, and IgG1 were not bound significantly. The number of binding sites per cell for IgG2a was 4 X 10(5) for thioglycollate-stimulated cells and 1 X 10(5) for normal and P388D1 cells. Binding was exothermal: with decreasing temperature the equilibrium (association) constants increased and dissociation rate constants decreased (at 37degreesC the respective values were 2 X 10(7) M-1 and 0.26 min-1, the latter value corresponds to a half time for dissociation of 2.6 min). From the rapidity of association and dissociation, it appears that the surface of the macrophage is in a dynamic equilibrium with IgG2a molecules in the cell's immediate microenvironment. The receptors for IgG2a are clearly specific for determinants in the immunoglobulin constant domain: two IgG2a proteins with greatly different isoelectric points (determined by isoelectric focusing) were bound with the same affinity to the same receptors; moreover, the Fc fragment was bound and Fab fragments were not. The Fc receptors for IgG2a proteins were readily eliminated by exposing macrophages briefly to trypsin. The receptors were regenerated during subsequent cultivation in serum-free medium; regeneration was inhibited totally by cycloheximide and partially by actinomycin D.