Efficient Payload Delivery by a Bispecific Antibody-Drug Conjugate Targeting HER2 and CD63
Efficient Payload Delivery by a Bispecific Antibody-Drug Conjugate Targeting HER2 and CD63
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DOI：
10.1158/1535-7163.mct-16-0364
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发表时间：
2016-11-01
影响因子：
5.7
通讯作者：
Parren, Paul W. H. I.
中科院分区：
文献类型：
--
作者：
de Goeij, Bart E. C. G.;Vink, Tom;Parren, Paul W. H. I.
抗体-药物缀合物（ADC）被设计为在循环中稳定，并且在肿瘤细胞中抗原特异性结合、摄取和降解后在细胞内释放有效的细胞毒性药物。因此，有效的内化和路由到可以发生蛋白水解的溶酶体是必不可少的。然而，对于肿瘤细胞上的许多细胞表面蛋白和碳水化合物结构来说，这些过程的幅度不足以实现有效的ADC方法。我们假设我们可以通过双特异性抗体（bsAb）方法增强溶酶体ADC递送来克服这种限制，其中一个结合结构域将提供肿瘤特异性，而另一个结合结构域将促进靶向溶酶体区室。因此，我们设计了一种bsAb，其中一个结合臂特异性靶向CD 63，一种被描述为在质膜和细胞内区室之间穿梭的蛋白质，并将其与HER 2结合臂组合在bsAb中，HER 2结合臂被选为肿瘤特异性结合的模型抗原。所得到的bsHER 2xCD 63（his）在HER 2阳性肿瘤细胞中表现出强结合、内化和溶酶体积累，并且最小限度地内化到HER 2阴性细胞中。通过将bsHER 2xCD 63（his）与微管破坏剂多司他丁-3缀合，我们能够证明bsHER 2xCD 63（his）-ADC对HER 2阳性肿瘤的有效细胞毒性，这在单价HER 2和CD 63特异性ADC中未观察到。我们的数据首次证明，使用靶向溶酶体膜蛋白CD 63的bsAb方法可以改善ADC的细胞内运输，并为开发将联合收割机肿瘤特异性靶向与快速内化抗原靶向相结合的新型bsADC提供了理论基础。(C)2016年AACR。
Antibody-drug conjugates (ADC) are designed to be stable in circulation and to release potent cytotoxic drugs intracellularly following antigen-specific binding, uptake, and degradation in tumor cells. Efficient internalization and routing to lysosomes where proteolysis can take place is therefore essential. For many cell surface proteins and carbohydrate structures on tumor cells, however, the magnitude of these processes is insufficient to allow for an effective ADC approach. We hypothesized that we could overcome this limitation by enhancing lysosomal ADC delivery via a bispecific antibody (bsAb) approach, in which one binding domain would provide tumor specificity, whereas the other binding domain would facilitate targeting to the lysosomal compartment. We therefore designed a bsAb in which one binding arm specifically targeted CD63, a protein that is described to shuttle between the plasma membrane and intracellular compartments, and combined it in a bsAb with a HER2 binding arm, which was selected as model antigen for tumor-specific binding. The resulting bsHER2xCD63(his) demonstrated strong binding, internalization and lysosomal accumulation in HER2-positive tumor cells, and minimal internalization into HER2-negative cells. By conjugating bsHER2xCD63(his) to the microtubule-disrupting agent duostatin-3, we were able to demonstrate potent cytotoxicity of bsHER2xCD63(his)-ADC against HER2-positive tumors, which was not observed with monovalent HER2- and CD63-specific ADCs. Our data demonstrate, for the first time, that intracellular trafficking of ADCs can be improved using a bsAb approach that targets the lysosomal membrane protein CD63 and provide a rationale for the development of novel bsADCs that combine tumor-specific targeting with targeting of rapidly internalizing antigens. (C) 2016 AACR.