Highly specific in vivo tumor targeting by monovalent and divalent forms of 741F8 anti-c-erbB-2 single-chain Fv.
Highly specific in vivo tumor targeting by monovalent and divalent forms of 741F8 anti-c-erbB-2 single-chain Fv.
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发表时间：
1993-09
期刊：
影响因子：
11.2
通讯作者：
Gregory P. Adams;J. Mccartney;M. Tai;Hermann Oppermann;James S. Huston;W. Stafford;M. Bookman;I. Fand;L. Houston;L. Weiner
中科院分区：
文献类型：
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作者：
Gregory P. Adams;J. Mccartney;M. Tai;Hermann Oppermann;James S. Huston;W. Stafford;M. Bookman;I. Fand;L. Houston;L. Weiner
在带有 SK-OV-3 肿瘤异种移植物的 scid 小鼠中检查了具有抗 c-erbB-2 单克隆抗体 741F8 特异性的单价和二价单链 Fv (sFv) 分子的体内特性。 741F8 sFv 单体表现出快速、双相的血液清除能力，而二价 741F8 (sFv')2 则观察到清除速度稍慢，该二价 741F8 (sFv')2 包含一对 741F8 sFv'，C 端 Gly4Cys 通过二硫键连接。静脉注射后注射后，741F8 sFv单体选择性保留在c-erbB-2过表达的SK-OV-3肿瘤中，24小时内肿瘤与正常器官的比例均超过10:1。通过生物分布研究、伽马相机成像和冷冻宏观放射自显影研究评估，抗地高辛 26-10 sFv 单体缺乏保留，证明了这种效应的特异性。 741F8 单体结合的特异性指数（741F8 sFv 保留/26-10 sFv 保留）通过每克组织注射剂量的百分比测量，对于肿瘤为 13.2:1，对于所有测试的正常器官为 0.8 至 2.1，肿瘤:器官比率的特异性指数范围为 7.0（肾脏）至 16.7（肠）。将二价 741F8 (sFv')2 与 26-10 (sFv')2 进行比较，出现相似的模式，Gly4Cys 连接的 (sFv')2 保留在肿瘤中的特异性指数为 16.9。这些数据表明，在静脉注射后。给药后，741F8 sFv 的单价和二价形式均被 SK-OV-3 肿瘤特异性保留。这种抗原特异性结合与 26-10 sFv 对照相结合，排除了肿瘤间质中的被动扩散和聚集对长期肿瘤定位有显着贡献的可能性。与 741F8 sFv 单体相比，具有肽间隔基的 741F8 (sFv')2 物种表现出二价结合并增加了在肿瘤中的保留。由于 (sFv')2 的血液保留时间比单体稍长，因此有必要证明肽连接的 (sFv')2 的肿瘤定位增加是由于其二价性质。与大约相同大小的单价 741F8 Fab 片段相比，二价双马来酰亚胺己烷连接的 741F8 (sFv')2 的定位明显更高，这表明 (sFv')2 的亲和力增加是其改善肿瘤保留的一个因素。这是通过二价形式的 sFv 分子成功体内特异性靶向肿瘤的第一份报告。肿瘤对特定二价 (sFv')2 的保留的改善可能对靶向诊断或治疗策略产生重要影响。
The in vivo properties of monovalent and divalent single-chain Fv (sFv)-based molecules with the specificity of the anti-c-erbB-2 monoclonal antibody 741F8 were examined in scid mice bearing SK-OV-3 tumor xenografts. 741F8 sFv monomers exhibited rapid, biphasic clearance from blood, while a slightly slower clearance was observed with the divalent 741F8 (sFv')2 comprising a pair of 741F8 sFv' with a C-terminal Gly4Cys joined by a disulfide bond. Following i.v. injection, the 741F8 sFv monomer was selectively retained in c-erbB-2-overexpressing SK-OV-3 tumor, with excellent tumor:normal organ ratios uniformly exceeding 10:1 by 24 h. The specificity of this effect was demonstrated by the lack of retention of the anti-digoxin 26-10 sFv monomer, as evaluated by biodistribution studies, gamma camera imaging, and cryomacroautoradiography studies. The specificity index (741F8 sFv retention/26-10 sFv retention) of 741F8 monomer binding, measured by the percentage of injected dose per g of tissue, was 13.2:1 for tumor, and 0.8 to 2.1 for all tested normal organs, with specificity indices for tumor:organ ratios ranging from 7.0 (kidneys) to 16.7 (intestines). Comparing divalent 741F8 (sFv')2 with the 26-10 (sFv')2, similar patterns emerged, with specificity indices for retention in tumor of 16.9 for the Gly4Cys-linked (sFv')2. These data demonstrate that, following their i.v. administration, both monovalent and divalent forms of 741F8 sFv are specifically retained by SK-OV-3 tumors. This antigen-specific binding, in conjunction with the 26-10 sFv controls, precludes the possibility that passive diffusion and pooling in the tumor interstitium contributes significantly to long-term tumor localization. 741F8 (sFv')2 species with peptide spacers exhibited divalent binding and increased retention in tumors as compared with 741F8 sFv monomers. Since the blood retention of the (sFv')2 is slightly more prolonged than that of the monomer, it was necessary to demonstrate that the increased tumor localization of the peptide-linked (sFv')2 was due to its divalent nature. The significantly greater localization of the divalent bismalimidohexane-linked 741F8 (sFv')2 as compared with a monovalent 741F8 Fab fragment of approximately the same size suggests that the increased avidity of the (sFv')2 is a factor in its improved tumor retention. This is the first report of successful specific in vivo targeting of tumors by divalent forms of sFv molecules. The improved retention of specific divalent (sFv')2 by tumors may have important consequences for targeted diagnostic or therapeutic strategies.