Comparison of different transient gene expression systems for the production of a new humanized anti-HER2 monoclonal antibody (Hersintuzumab)

Background Producing therapeutic proteins can be done quickly and on a large scale through Transient Gene Expression (TGE). Chinese hamster ovary (CHO) cell lines are commonly used to achieve this. Although there are few comparative studies, TGE has been observed in suspension-adapted CHO cells. Objectives We tested TGE’s effectiveness in DG-44, CHO-S, and ExpiCHO-S cell lines with four transfection reagents. Methods A design of experiments (DoE) was followed to optimize transfection using a recombinant monoclonal antibody (mAb) construct. To evaluate the efficacy, flow cytometry and ELISA were used. Feeding strategies and temperature shifts were implemented to enhance transfection effectiveness. The quality of the mAb was assessed through ELISA, SDS-PAGE, and proliferation inhibition assays. Results We adapted all cell lines to grow in suspension using a serum-free medium. Our findings from flow cytometry and ELISA tests indicate that PEI and Pmax reagents had a higher rate of transfection and mAb production than the ExpiCHO commercial transfection reagent. While DG-44 cells had better transfection efficiency than CHO-S and ExpiCHO-S, there was no significant difference between CHO-S and ExpiCHO-S. Our TGE system was more productive at 32 °C than at 37 °C. In the optimized TGE of Pmax-based transfection in DG-44 at 37 and 32 °C, the production level of mAb was more than half of the amount of the commercial ExpiCHO-S expression system. Still, the number of transfected cells was three times higher, making it more efficient. The purified mAb from all transfected cell lines had similar structural and functional properties under different conditions. Conclusion Our research shows that using Pmax and DG-44 cells in the TGE system is a cost-effective and efficient way to produce humanized monoclonal antibodies. We discovered that this method outperforms the ExpiCHO-S kit. Graphical abstract