Ahmadvand Davoud, Rasaee Mohammad J, Rahbarizadeh Fatemeh, Mohammadi Mohammad
Department of Clinical Biochemistry, School of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
Hybridoma (Larchmt). 2008 Oct;27(5):353-60. doi: 10.1089/hyb.2008.0014.
Abstract Antibodies or antibody fragments are almost exclusively applied in human therapy and diagnosis. The high affinity and specificity of antibodies makes them suitable for these applications. Nanobody, the variable domain of Camelidae heavy chain antibodies, have superior properties compared with conventional antibodies in that they are small, non-immunogenic, very stable, highly soluble, and easy to produce in large quantities. In the present study, we report the isolation and characterization of a high-affinity binder against human endoglin retrieved from camels' nanobody gene library. Endoglin (CD105), an accessory protein of the transforming growth factor beta receptor complex, has become an attractive molecule for the targeting of the tumor vasculature. Upregulation of endoglin on proliferating endothelial cells is associated with tumor neovascularization. Here, we generated two nanobody gene libraries displayed on phage particles. Some single-domain antibody fragments have been isolated that specifically recognize the recombinant extracellular domain of human endoglin. The other selected anti-endoglin nanobody (AR1-86) showed strong binding to human endoglin expressing endothelial cells (HUVECs), while no binding was observed with the endoglin-negative cell line (HEK293). This high-affinity single-domain antibody could be a good candidate for the generation of vascular or tumor targeting agents in cancer therapy.
摘要 抗体或抗体片段几乎仅应用于人类治疗和诊断。抗体的高亲和力和特异性使其适用于这些应用。纳米抗体是骆驼科动物重链抗体的可变结构域，与传统抗体相比具有卓越的特性，因为它们体积小、无免疫原性、非常稳定、高度可溶且易于大量生产。在本研究中，我们报告了从骆驼纳米抗体基因文库中筛选出的一种针对人内皮糖蛋白的高亲和力结合物的分离和表征。内皮糖蛋白（CD105）是转化生长因子β受体复合物的辅助蛋白，已成为靶向肿瘤血管系统的一个有吸引力的分子。增殖内皮细胞上内皮糖蛋白的上调与肿瘤新生血管形成有关。在此，我们构建了两个展示在噬菌体颗粒上的纳米抗体基因文库。已分离出一些特异性识别重组人内皮糖蛋白胞外结构域的单域抗体片段。另一个筛选出的抗内皮糖蛋白纳米抗体（AR1-86）与表达人内皮糖蛋白的内皮细胞（HUVECs）有强烈结合，而在内皮糖蛋白阴性细胞系（HEK293）中未观察到结合。这种高亲和力的单域抗体可能是癌症治疗中生成血管或肿瘤靶向药物的良好候选物。
