Development of cell internalizing antibody as a safe and nontoxic imaging tool

为了开发抗死亡蛋白抗体在诊断和递送方面的应用，我们产生了新的抗体并进行了鉴定。我们发现细胞内化抗体和非内化抗体具有明显不同的表位。采用多重抑制法确定内化机制。我们发现制霉菌素对抗体内化的抑制作用最强，这意味着它参与了脂筏介导的内吞作用。接下来，我们使用了三种筏子通路的特定抑制剂。内化作用可被动力蛋白抑制剂强烈抑制。而小窝蛋白-1抑制剂和CdC42抑制剂的作用较弱。结论：新的内化抗死亡蛋白抗体的内化主要是由动力蛋白和小窝蛋白依赖的内吞作用介导的。

In order to develop application of anti-mortalin antibody for diagnostics and delivery, we generated new antibodies and performed a characterization. We found that the cell internalizing and non-internalizing antibodies possess distinctly different epitopes. Mechanism of internalization was determined by adopting multiple inhibitor approach. We found that the antibody internalization was inhibited most strongly by Nystatin, implying that it involves lipid raft mediated endocytosis. We next used specific inhibitors of three raft pathways. The internalization was strongly inhibited by dynamin inhibitor. On the other hand, caveolin-1 inhibitor and CDC42 inhibitor showed weak effect. It was concluded that the internalization of new internalizing anti-mortalin antibodies is mostly mediated by Dynamin and Caveolin dependent endocytosis.