INVIVO TUMOR TARGETING OF A RECOMBINANT SINGLE-CHAIN ANTIGEN-BINDING PROTEIN
INVIVO TUMOR TARGETING OF A RECOMBINANT SINGLE-CHAIN ANTIGEN-BINDING PROTEIN
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DOI：
10.1093/jnci/82.14.1191
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发表时间：
1990-07-18
影响因子：
10.3
通讯作者：
SCHLOM, J
中科院分区：
文献类型：
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作者：
COLCHER, D;BIRD, R;SCHLOM, J
我们在这里描述的第一个在体内靶向肿瘤的单链抗原结合蛋白。该分子在大肠杆菌中构建和表达，是一种新型重组蛋白，由可变轻链（VL），免疫球蛋白的氨基酸序列通过设计的肽连接到可变重链（VH）序列组成。我们发现，这种蛋白质，来自抗肿瘤单克隆抗体B6.2的可变区的DNA序列，具有相同的体外抗原结合特性的B6.2 Fab“framgent。在无胸腺小鼠中的比较药代动力学研究表明，单链抗原结合蛋白的血浆清除的α和β相比FAb片段快得多，以及非常快速的全身清除。单链抗原结合蛋白清除的α和β相的半衰期值分别为2.4分钟和2.8小时，而Fab“为14.8分钟和7.5小时。此外，单链抗原结合蛋白分子没有显示出如Fab“分子或如前所示的F（ab”）2分子那样在肾中蓄积。尽管其快速清除，但单链抗原结合蛋白在人肿瘤异种移植物中的摄取与Fab“片段相当，导致肿瘤与正常组织的比率与Fab”片段相当或更高。因此，这些研究证明了重组单链抗原结合蛋白的体内稳定性及其在癌症和其他疾病的一些诊断和治疗临床应用中的潜力。
We describe here the first in vivo targeting of tumors with a single-chain antigen-binding protein. The molecule, which was constructed and expressed in Escherichia coli, is a novel recombinant protein composed of a variable light-chain (VL), amino acid sequence of an immunoglobulin tethered to a variable heavy-chain (VH) sequence by a designed peptide. We show that this protein, derived from the DNA sequence of the variable regions of the antitumor monoclonal antibody B6.2, has the same in vitro antigen-binding properties as the B6.2 Fab'' framgent. Comparative pharmacokinetic studies in athymic mice demonstrate much more rapid alpha and beta phases of plasma clearance for the single-chain antigen-binding protein than for the FAb'' fragment, as well as an extremely rapid whole-body clearance. Half-life values for alpha and beta phases of single-chain antigen-binding protein clearance were 2.4 minutes and 2.8 hours, respectively, versus 14.8 minutes and 7.5 hours for Fab''. Furthermore, the single-chain antigen-binding protein molecule did not show accumulation in the kidney as did the Fab'' molecule or, as previously shown, the F(ab'')2 molecule. Despite its rapid clearance, the single-chain antigen-binding protein showed uptake in a human tumor xenograft comparable to that of the Fab'' fragment, resulting in tumor to normal tissue ratios comparable to or greater than those obtained with the Fab'' fragment. These studies thus demonstrate the in vivo stability of recombinant single-chain antigen-binding proteins and their potential in some diagnostic and therapeutic clinical applications in cancer and other diseases.