Fc receptor-mediated binding and endocytosis by human mononuclear phagocytes: monomeric IgG is not endocytosed by U937 cells and monocytes.
Fc receptor-mediated binding and endocytosis by human mononuclear phagocytes: monomeric IgG is not endocytosed by U937 cells and monocytes.
复制标题
FC受体介导的人类单核吞噬细胞的结合和内吞作用：单体IgG不受U937细胞和单核细胞的内吞。
DOI：
10.1083/jcb.100.2.558
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发表时间：
1985-02
影响因子：
7.8
通讯作者：
Anderson, C L
中科院分区：
文献类型：
--
作者：
Jones, D H;Nusbacher, J;Anderson, C L
在聚集的IgG和胰岛素容易发生受体介导的内化的条件下，评价了Fc受体介导的人单核吞噬细胞对单体IgG 1的内吞作用。将U937细胞或正常人外周血单核细胞在0 ℃下首先结合125 I-IgG 1后，在37 ℃下在不存在游离放射性配体的情况下孵育。为了测定在37 ℃孵育不同时间后内化的细胞相关IgG 1的量，通过将细胞在0 ℃下连续暴露于非特异性蛋白酶1小时并暴露于pH 3.2的乙酸3分钟来去除表面结合的IgG 1。类似于在37 ℃下用125 I-胰岛素和125 I-聚集的IgG进行的平行实验中随时间观察到的，并且随着时间的推移从相同细胞释放到培养基中的IgG 1缺乏降解，这表明这些细胞不内吞和降解单体IgG，Fc受体特异性机制，并表明，组成性回收没有降解是不可能发生的。这些数据满足受体-受体相互作用触发Fc受体介导的内吞作用的假设的一个预测。
Fc receptor-mediated endocytosis of monomeric IgG1 by human mononuclear phagocytes was evaluated under conditions where aggregated IgG and insulin readily undergo receptor-mediated internalization. U937 cells or normal human peripheral blood monocytes were incubated at 37 degrees C in the absence of free radioligand after having first bound 125I-IgG1 at 0 degrees C. To determine the amount of cell-associated IgG1 internalized after varying periods of 37 degrees C incubation, surface- bound IgG1 was removed by sequential exposure of cells at 0 degrees C to a nonspecific proteinase for 1 h and to acetic acid at pH 3.2 for 3 min. The failure to develop a proteinase- and acid-resistant fraction, similar to that seen over time at 37 degrees C in parallel experiments with 125I-insulin and 125I-aggregated IgG, and the lack of degradation of the IgG1 released into the medium from the same cells over time show that these cells do not endocytose and degrade monomeric IgG by an Fc receptor-specific mechanism and suggest that constitutive recycling without degradation is unlikely to be occurring. These data fulfill one prediction of the hypothesis that receptor-receptor interaction triggers Fc receptor-mediated endocytosis.