The effect of Ccnb1ip1 insulator on monoclonal antibody expression in Chinese hamster ovary cells

Background The increasing need for therapeutic monoclonal antibodies (mAbs) entails the development of innovative and improved expression strategies. Chromatin insulators have been utilized for the enhancement of the heterologous proteins in mammalian cells. Methods and results In the current study the Ccnb1ip1 gene insulator element was utilized to construct a novel vector system for the expression of an anti-CD52 mAb in Chinese hamster ovary (CHO) cells. The insulator containing (pIns-mAb) and control (pmAb) vectors were generated and stable cell pools were established using these constructs. The expression level in the cells created with pIns-mAb vector was calculated to be 233 ng/mL, and the expression rate in the control vector was 210 ng/mL, which indicated a 10.9% increase in mAb expression in pIns-mAb pool. In addition, analysis of mAb expression in clonal cells established from each pool showed a 10% increase in antibody productivity in the highest mAb producing clone derived from the pIns-mAb pool compared to the clone isolated from pmAb pool. Conclusions More studies are needed to fully elucidate the effects of Ccnb1ip1 gene insulator on recombinant therapeutic protein expression in mammalian cells. The combination of this element with other chromatin-modifying elements might improve its augmentation effect which could pave the way for efficient and cost-effective production of therapeutic drugs.