Production of recombinant human growth hormone by rCHO cells in a depth filter perfusion system

Human growth hormone is a single-chain polypeptide produced commercially from recombinant animal cells as well as recombinant microorganisms. Its increased applications have requested development of highly efficient production systems using particularly animal cells. Depth filter perfusion system (DFPS) has been developed and successfully used for production of recombinant proteins such as antibodies from recombinant Chinese hamster ovary (rCHO) cells. In this study, rCHO cells expressing recombinant human growth hormone (rhGH) were successfully cultivated in the DFPS for 2,200 h. Parameters affecting the performance of the DFPS for rhGH production were investgated. The depth filter with 40 µm pores was selected for stable operation. The shifts of culture temperature and pH were tested at 37 and 33℃, and 7.2 and 7.0, respectively. In the begining of the culture, more than 80% of the seeded cells were immobilized in 200 min by medium/cell circulation. When the culture temperature was lowered from 37 to 33℃, about 50% increase of the volumetric productivity (VP) at a perfusion rate of 2.0/day was achieved, and the VP reached 168 mg/L/d at perfusion rate of 3.0/day, showing the benefit of cultures in low temperature. In contrast, when pH was shifted from 7.2 to 7.0, maintaining rhGH concentration at about 60 mg/L and decreased perfusion rate from 2.0 to 1.0/day, the VP dropped to 50%. As the DFPS showed stable and efficient production of rhGH for long-term periods from this study, it can be an attractive choice for production of rhGH from recombinant animal cells.