Antineoplastic effect of anti-erbB-2 intrabody is not correlated with scFv affinity for its target
Antineoplastic effect of anti-erbB-2 intrabody is not correlated with scFv affinity for its target
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DOI：
10.1038/sj.cgt.7700228
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发表时间：
2000-09-01
影响因子：
6.4
通讯作者：
Curiel, DT
中科院分区：
文献类型：
--
作者：
Arafat, W;Gómez-Navarro, J;Curiel, DT
细胞内单链抗体（scFvs）已经成为敲除癌蛋白表达的有力方法。我们先前已经证明针对多种分子靶点的scfvs在肿瘤细胞中诱导特异性毒性。最近，抗erbB-2单链抗体的效用已经预测了其在I期基因治疗临床试验中的评价。scFv作为胞内抗体的效用与其与靶标的相互作用密切相关，限制了后者对肿瘤表型的贡献。在这项研究中，我们试图确定scFv对其同源靶标的亲和力的提高是否可以提高胞内抗体介导的癌蛋白敲除的效率。我们在erbB-2阳性和阴性肿瘤细胞中比较了编码新开发的C6.5抗erbB-2 scFv的质粒的功能，该scFv与我们的原始e23抗erbB-2 scFv具有1000倍的亲和力。发现细胞内scFv表达、靶结合和肿瘤细胞毒性在所有测试条件下相似，包括用scFv的有限稀释的剂量-反应研究。在此基础上，我们得出结论，抗erbB-2胞内抗体的抑制作用与scFv对其靶标的亲和力无关。
Intracellular single-chain antibodies (scFvs) have emerged as a powerful method to knock out expression of oncoproteins. We have demonstrated previously that scfvs directed against a variety of molecular targets induce specific toxicity in tumor cells. Recently, the utility of an anti-erbB-2 scFv has predicated its evaluation in a phase I gene therapy clinical trial. The utility of scFv as an intrabody is closely linked to its interaction with a target, Limiting the contribution of the latter to the neoplastic phenotype. In this study, we sought to determine whether improvement in the affinity of the scFv far its cognate target could improve the efficiency of intrabody-mediated oncoprotein knockout. We compared in erbB-2-positive and -negative tumor cells the function of plasmids encoding a newly developed C6.5 anti-erbB-2 scFv, which has a 1000-fold higher affinity, with our original e23 anti-erbB-2 scFv. Intracellular scFv expression, target binding, and tumor cell cytotoxicity were found to be similar in all conditions tested, including dose-response studies with limiting dilutions of the scFv. On this basis, we have concluded that the antineoplastic effect of anti-erbB-2 intrabody is not correlated with scFv affinity for its target.