Abstract
Chinese hamster ovary (CHO) cells are the most important host system used for monoclonal antibody (mAb) expression. Moreover, the fed-batch culture mode is the most widely used method to increase mAb expression in CHO cells by increasing the amount of feed. However, a high amount of culture feed results in the production of metabolic byproducts. In this work, we used a continuous feeding strategy to reduce metabolic byproducts and improve mouse–human chimeric anti-epidermal growth factor receptor vIII (EGFRvIII) antibody C12 expression in Chinese hamster ovary-K1 cells. Moreover, the effects of the feeding strategy on the cell culture and monoclonal antibody production were evaluated in chemically defined suspension cultures of recombinant CHO-K1 cells. Compared with bolus feeding methods, the continuous feeding method did not have any advantages when the feeding amount was low, but with a high feeding amount, the continuous feeding method significantly reduced the concentrations of lactate and NH4+ in the later culture stage. At the end of the culture stage, compared with bolus feeding methods, the lactate and NH4+ concentrations under the continuous feeding mode were reduced by approximately 45% and 80%, respectively. In addition, the antibody C12 expression level was also increased by almost 10%. Compared to the bolus feeding method, the antibody C12 produced by the continuous feeding method had a lower content of high-mannose glycoforms. Further analysis found that the osmolality of the continuous feeding method was lower than that of the typical fed-batch bolus feeding method. Conclusively, these results indicate that the continuous feeding method is very useful for reducing metabolic byproducts and achieving higher levels of mAb production.
Highlights
Since the approval of the first therapeutic antibody drug orthoclone OKT3 by the USA Food and Drug Administration (FDA) in 1986, antibody drugs have become the fastest growing sector of drug development in the world after more than 30 years of technological breakthroughs [1,2]
The two glutamine synthetase (GS) Chinese hamster ovary (CHO) cell lines used in this study to produce EGFRvIII antibody C12 were generated from CHO-K1 cells, as described previously [18], and were adapted to suspension culture, with have the ability to grow in serum-free medium
At a low feeding amount (Figure 1a,d), there were no significant difference in cell growth for both cell lines A and B among the three different feeding methods; these may be because the CHO cells did not produce many metabolic byproducts when the feeding amount was low [19], so the cell growth was similar under the three feeding methods
Summary
Since the approval of the first therapeutic antibody drug orthoclone OKT3 by the USA Food and Drug Administration (FDA) in 1986, antibody drugs have become the fastest growing sector of drug development in the world after more than 30 years of technological breakthroughs [1,2]. 70% of the postlaunch therapeutic proteins are expressed by CHO cells [4,5,6] In recent years, these biological agents have often been used by patients in large quantities, and their global demand is rapidly increasing. It is very urgent to increase the protein expression level of CHO cells and reduce the cost of production. It is very important to control metabolic byproducts at low concentration levels; controlling the lactate and NH4+ concentrations is a major challenge in cell culture technology [13]. A high feeding amount will cause more cell metabolism byproducts, which will eventually affect the stability of the process and even reduce the protein expression. Solving a series of problems caused by high feeding amounts is very important to reduce the cost of biopharmaceuticals
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
