Effect of the anti-receptor ligand-blocking 225 monoclonal antibody on EGF receptor endocytosis and sorting
Effect of the anti-receptor ligand-blocking 225 monoclonal antibody on EGF receptor endocytosis and sorting
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DOI：
10.1016/j.yexcr.2006.05.008
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发表时间：
2006-09-10
影响因子：
3.7
通讯作者：
McCourt, Maureen O'Connor
中科院分区：
文献类型：
--
作者：
Jaramillo, Maria L.;Leon, Zully;McCourt, Maureen O'Connor
已知抗受体抗体225 mAb可阻断配体与表皮生长因子受体（EGFR）的结合。然而，这种中和抗体对EGFR内吞、运输和降解的影响仍不清楚。在这里，我们证明了I-125-225 mAb的内吞作用发生，尽管速率比EGF慢。使用脉冲追踪测定，我们表明，内化的I-125-225单克隆抗体被回收到表面比内化的I-125-EGF更有效。此外，我们发现，与EGF相反，I-125-225 mAb的内化不依赖于受体酪氨酸激酶活性，这一点可以通过其对AG 1478（一种特异性EGFR酪氨酸激酶抑制剂）的不敏感性来证明。对细胞表面和总EGFR水平的分析显示，用225 mAb处理导致表面EGFR降低30-40%和总EGFR相对缓慢的下调。总之，这些数据表明，225 mAb通过与EGF诱导的EGFR内化和下调不同的机制诱导EGFR内化和下调。皇冠版权所有（c）2006由爱思唯尔公司出版。All rights reserved.
The anti-receptor antibody, 225 mAb, is known to block binding of ligand to the epidermal growth factor receptor (EGFR). However, the effect of this neutralizing antibody on EGFR endocytosis, trafficking and degradation remains unclear. Here, we demonstrate that endocytosis of I-125-225 mAb occurs, albeit with a slower rate than that of EGF. Using pulse chase assays, we show that internalized I-125-225 mAb is recycled to the surface much more efficiently than internalized I-125-EGF. Also, we found that internalization of I-125-225 mAb, in contrast to that of EGF, is independent of receptor tyrosine kinase activity, as evidenced by its insensitivity to AG1478, a specific EGFR tyrosine kinase inhibitor. Analysis of the levels of cell surface and total EGFR showed that treatment with 225 mAb results in a 30-40% decrease in surface EGFR and a relatively slow downregulation of total EGFR. Taken together, these data indicate that 225 mAb induces internalization and downregulation of EGFR via a mechanism distinct from that underlying EGF-induced EGFR internalization and downregulation. Crown Copyright (c) 2006 Published by Elsevier Inc. All rights reserved.