Evaluation of a novel human IgG1 anti-claudin3 antibody that specifically recognizes its aberrantly localized antigen in ovarian cancer cells and that is suitable for selective drug delivery.
Evaluation of a novel human IgG1 anti-claudin3 antibody that specifically recognizes its aberrantly localized antigen in ovarian cancer cells and that is suitable for selective drug delivery.
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DOI：
10.18632/oncotarget.5315
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发表时间：
2015-10-27
期刊：
影响因子：
--
通讯作者：
Mitola S
中科院分区：
文献类型：
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作者：
Romani C;Cocco E;Bignotti E;Moratto D;Bugatti A;Todeschini P;Bandiera E;Tassi R;Zanotti L;Pecorelli S;Sartori E;Odicino FE;de Marco A;Santin AD;Ravaggi A;Mitola S
膜蛋白克劳丁3最近被认为是具有生物侵袭性肿瘤的标志物，以及活性抗癌化合物治疗性递送的可能靶点。克劳丁3结合分子，如产气荚膜梭菌肠毒素（CPE）、CPE相关分子以及鼠源和嵌合抗体，在临床前肿瘤学环境中已显示出有前景的抗肿瘤功效。我们首先通过将人IgG1 Fc结构域与先前从免疫前噬菌体展示文库中分离出的抗克劳丁3单链抗体片段（scFvH6）融合，构建了一种全人源抗克劳丁3 IgG1抗体（IgGH6）。该构建体在哺乳动物细胞中表达，并特异性靶向在不同人卵巢癌细胞系表面内源性表达的克劳丁3。未观察到与其他同源克劳丁蛋白的可检测交叉反应。IgGH6识别的表位位于克劳丁3的小细胞外结构域内，并且仅在连接形成不完全的肿瘤细胞中可及。共聚焦显微镜实验表明，IgGH6在与天然克劳丁3结合后在肿瘤细胞中被主动内化，并可能在细胞内囊泡内与C - CPE肽共定位。初步结果显示，IgGH6在体内在表达游离克劳丁3的卵巢癌异种移植物中积累。由于其在肿瘤细胞中的选择性摄取以及其人源特性，IgGH6是卵巢癌患者抗体 - 药物偶联物治疗应用的有价值候选者。
Membrane protein claudin3 has been recently suggested as a marker for biologically aggressive tumors and a possible target for the therapeutic delivery of active anti-cancer compounds. Claudin3-binding molecules such as the Clostridium perfringens enterotoxin (CPE), CPE-related molecules, and murine and chimeric antibodies have shown promising antitumor efficacy in preclinical oncological settings. We first engineered a fully human anti-claudin3 IgG1 antibody (IgGH6) by fusing the human IgG1 Fc-domain to the anti-claudin3 scFvH6 previously isolated from a pre-immune phage display library. The construct was expressed in mammalian cells and specifically targeted claudin3 endogenously expressed on the surface of different human ovarian cancer cell lines. No detectable cross-reactivity with other homologous claudins was observed. The epitope recognized by IgGH6 is located within the minor extracellular domain of claudin3 and becomes accessible only in tumor cells characterized by incomplete junction formation. Confocal microscopy experiments demonstrated that IgGH6 was actively internalized in tumor cells after binding to native claudin3 and co-localized, likely within intracellular vesicles, with the C-CPE peptide. Preliminary results indicate that IgGH6 accumulated in vivo in free claudin3 ovarian carcinoma xenografts. For its selective uptake in tumor cells and its human nature, IgGH6 represents a valuable candidate for antibody-drug conjugate therapeutic applications in ovarian cancer patients.