Perez Lincidio, Ayala Marta, Pimentel Gilmara, Bell Hanssel, Canaán-Haden Leonardo, Bequet Mónica, González Luis Javier, Miranda Marlen, Ravelo Rolando, Roque Lourdes, Acevedo Boris, Oliva Juan P, Gavilondo Jorge V
Recombinant Antibody Group, Cancer Research Department, Center for Genetic Engineering and Biotechnology, Havana 10600, Cuba.
Biotechnol Appl Biochem. 2006 Jan;43(Pt 1):39-48. doi: 10.1042/BA20050073.
In the present paper we report the development of a bivalent scFv (single-chain Fv) antibody fragment, starting from a mouse mAb (monoclonal antibody) specific for CEA (carcinoembryonic antigen) that has received approval for in vivo radioimmunodiagnosis in humans. The diabody is well expressed in Escherichia coli, is easily purified by a combination of immobilized metal ion affinity chromatography and gel filtration and exhibits high affinity and specificity for CEA, comparable with those of the original mAb. Biodistribution experiments in athymic nude mice transplanted with human CEA+ cancer cells showed that the 125I-labelled diabody preferentially localizes in the tumour tissue and that retention is still high 48 h after injection. The diabody can be advantageous for some in vivo tumour targeting applications, due to the faster clearance derived from its smaller molecular mass.
在本论文中，我们报道了一种二价单链抗体片段（scFv）的研发情况，其起始于一种对癌胚抗原（CEA）具有特异性的小鼠单克隆抗体（mAb），该抗体已获批用于人体体内放射免疫诊断。双抗体在大肠杆菌中表达良好，通过固定化金属离子亲和色谱法和凝胶过滤法相结合可轻松纯化，并且对CEA表现出高亲和力和特异性，与原始单克隆抗体相当。在用人类CEA阳性癌细胞移植的无胸腺裸鼠中进行的生物分布实验表明，125I标记的双抗体优先定位于肿瘤组织，并且在注射后48小时仍保持高滞留率。由于其较小的分子量导致清除速度更快，双抗体对于某些体内肿瘤靶向应用可能具有优势。
