单链抗体的制备及其在肿瘤诊疗中的应用

Production of Single-chain Fragment Variable and Its Application in Tumor Diagnosis and Treatment

单链抗体(single-chain fragment variable,scFv)是由可变重链(VH)和可变轻链(VL)通过柔性肽接头连接在一起的小分子重组抗体。从杂交瘤中分离单链抗体的mRNA,逆转录成cDNA作为单链抗体基因扩增的模板,可得到包含大量不同VH和VL片段的单链抗体的基因文库。利用展示技术完成单链抗体亲和力和特异性筛选及鉴定,得到的单链抗体可通过各种表达系统成功表达单链抗体的蛋白质。虽然单链抗体分子量小,但已包含了完整抗体的抗原结合域,对抗原具有高特异性、高亲和力及低免疫原性,还具有较好的肿瘤组织穿透和扩散能力。因此,单链抗体已成为肿瘤诊疗方法开发中的研究热点。详细介绍了单链抗体的制备方法和问题,重点阐述了单链抗体在肿瘤诊断和治疗中的研究进展,以期为单链抗体制备及其治疗和诊断肿瘤提供理论依据。

Single-chain fragment variable(scFv)is a small molecule recombinant antibody consisting of a variable heavy chain(VH)and a variable light chain(VL)linked together by a flexible peptide junction.The mRNA of single chain antibodies is isolated mainly from hybridomas and reverse transcribed into cDNA as a template for scFv gene amplification,resulting in a gene library containing a large number of different VH and VL fragments of scFv.Screening and identification of the affinity and specificity of the scFv is accomplished using different display techniques,and the resulting scFv can be used to successfully express its proteins through various expression systems.Despite its small molecular weight,scFv contains the antigen-binding domain of intact antibodies and has high specificity and affinity for antigens,as well as low immunogenicity,and also has a strong ability to penetrate and spread through tumor tissue.Therefore,scFv has become a hot research topic in the development of oncology therapeutic approaches.This review details the methods and problems in the preparation of scFv and focuses on the research progress of scFv in tumor diagnosis and treatment,with a view to providing a theoretical basis for the preparation of scFv and its application in diagnosis and treatment of tumors.