Mohammadian Omid, Rajabibazl Masoumeh, Pourmaleki Es'hagh, Bayat Hadi, Ahani Roshanak, Rahimpour Azam
a Department of Clinical Biochemistry, School of Medicine, Shahid Beheshti University of Medical Sciences , Tehran , Iran.
b Nano-Technology and Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences , Tehran , Iran.
Prep Biochem Biotechnol. 2019;49(8):822-829. doi: 10.1080/10826068.2019.1621893. Epub 2019 Jun 1.
Therapeutic monoclonal antibodies (mAbs) have become the dominant products in biopharmaceutical industry. Mammalian cell expression systems including Chinese hamster ovary (CHO) cells are the most commonly used hosts for the production of complex recombinant proteins. However, development of stable, high producing CHO cell lines suffers from the low expression level and instability of the transgene. The increasing efforts in the development of novel therapeutic antibodies and the advent of biosimilars have revealed the necessity for the development of improved platforms for rapid production of products for initial characterization and testing. In line with this premise, vector design and engineering has been applied to improve the expression level and stability of the transgene. This study reports the application of an improved lentiviral vector system containing the human interferon-β scaffold attachment region (IFN-SAR) for the development of antibody producing stable CHO cells. mAb expressing clones producing 1100 µg/L of IgG1 monoclonal antibody were isolated without extensive screening of a large number of clones. Our results here indicate the positive effects of IFN-SAR on stable mAb expression using lentiviral based expression vectors. We also observed that although IFN-SAR can improve light chain (LC) and heavy chain (HC) gene copy numbers in stable cell pools, mAb expression in single cell clones was not affected by the transgene copy number.
治疗性单克隆抗体（mAb）已成为生物制药行业的主导产品。包括中国仓鼠卵巢（CHO）细胞在内的哺乳动物细胞表达系统是生产复杂重组蛋白最常用的宿主。然而，稳定高产CHO细胞系的开发面临着转基因表达水平低和不稳定的问题。新型治疗性抗体开发的不断努力以及生物类似药的出现，凸显了开发改进平台以快速生产用于初步表征和测试的产品的必要性。基于这一前提，载体设计和工程已被应用于提高转基因的表达水平和稳定性。本研究报道了一种含有人类干扰素-β支架附着区域（IFN-SAR）的改进慢病毒载体系统在开发产生抗体的稳定CHO细胞中的应用。无需对大量克隆进行广泛筛选，就分离出了产生1100μg/L IgG1单克隆抗体的mAb表达克隆。我们的结果表明IFN-SAR对使用慢病毒表达载体的稳定mAb表达具有积极作用。我们还观察到，尽管IFN-SAR可以提高稳定细胞库中轻链（LC）和重链（HC）基因的拷贝数，但单细胞克隆中的mAb表达不受转基因拷贝数的影响。
