Visualizing the site and dynamics of IgG salvage by the MHC class I-related receptor, FcRn
Visualizing the site and dynamics of IgG salvage by the MHC class I-related receptor, FcRn
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DOI：
10.4049/jimmunol.172.4.2021
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发表时间：
2004-02-15
影响因子：
4.4
通讯作者：
Ward, ES
中科院分区：
文献类型：
--
作者：
Ober, RJ;Martinez, C;Ward, ES
MHC-I类相关受体FcRN在调节血清免疫球蛋白水平中起着重要作用。FERN在内皮细胞中表达，提示这些细胞可能参与维持免疫球蛋白水平。我们使用FcRN-绿色荧光蛋白转染的人内皮细胞的活细胞成像来分析控制免疫球蛋白稳态的细胞内事件。我们发现FcRN-Ig G复合体与未结合的Ig G在分选的内体中发生分离。FcRN或FcRN-Ig G复合体逐渐从内体分选中耗尽，最终产生内容注定要被溶酶体降解的多囊体。此外，尽管配体摄取的机制不同，FcRN和转铁蛋白受体采取的途径是重叠的。这些研究为FcRN及其配体的运输提供了一个动态的视角，并与理解FcRN如何发挥作用以维持免疫球蛋白稳态有关。
The MHC class I-related receptor, FcRn, plays a central role in regulating the serum levels of IgG. FeRn is expressed in endothelial cells, suggesting that these cells may be involved in maintaining IgG levels. We have used live cell imaging of FcRn-green fluorescent protein transfected human endothelial cells to analyze the intracellular events that control IgG homeostasis. We show that segregation of FcRn-IgG complexes from unbound IgG occurs in the sorting endosome. FcRn or FcRn-IgG complexes are gradually depleted from sorting endosomes to ultimately generate multivesicular bodies whose contents are destined for lysosomal degradation. In addition, the pathways taken by FcRn and the transferrin receptor overlap, despite distinct mechanisms of ligand uptake. The studies provide a dynamic view of the trafficking of FcRn and its ligand and have relevance to understanding how FcRn functions to maintain IgG homeostasis.