Owens R J, Young R J
Calltech, Ltd., Berkshire, UK.
J Immunol Methods. 1994 Feb 10;168(2):149-65. doi: 10.1016/0022-1759(94)90051-5.
A number of recent technological developments have greatly facilitated the genetic engineering of immunoglobulins. The use of PCR has permitted the variable regions to be rapidly cloned either from a specific hybridoma source or as a gene library from non-immunised cells. The conversion of the rodent antibody into a humanized version is now well established. To develop these antibodies for clinical use has required the development of high level expression systems. For the expression of large multimeric glycoproteins, mammalian cell systems generally provide the highest levels of secreted product and therefore are the methods of choice for producing whole recombinant antibodies. Novel antigen-binding units have been developed by joining the two variable domains of an antibody into single-chain polypeptides. Such fragments can be produced in high yield by secretion from E. coli raising the prospect of bulk preparation of these antibody fragments for the development of low-cost immunopurification and assay reagents. Finally, the ability to screen for antigen binding by displaying immunoglobulin variable regions on the surface of filamentous bacteriaphages has opened up the possibility of bypassing the immune system to generate novel antibody specificities in vitro.
最近的一些技术发展极大地促进了免疫球蛋白的基因工程。聚合酶链反应（PCR）的应用使得可变区能够迅速从特定的杂交瘤来源克隆出来，或者作为来自未免疫细胞的基因文库进行克隆。将啮齿动物抗体转化为人源化版本的技术现已成熟。为了将这些抗体开发用于临床，需要开发高水平表达系统。对于大型多聚体糖蛋白的表达，哺乳动物细胞系统通常能提供最高水平的分泌产物，因此是生产完整重组抗体的首选方法。通过将抗体的两个可变结构域连接成单链多肽，已开发出新型抗原结合单元。通过大肠杆菌分泌可高产这些片段，这为大规模制备这些抗体片段以开发低成本免疫纯化和检测试剂带来了希望。最后，通过在丝状噬菌体表面展示免疫球蛋白可变区来筛选抗原结合的能力，为绕过免疫系统在体外产生新型抗体特异性开辟了可能性。
