Process development for production of recombinant antibody by rCHO cells

Abstract

A serum-free medium (SFM-MDM) without any animal-driven protein was developed for the production of recombinant antibody in suspension cultures of recombinant Chinese hamster ovary (CHO) cell line, CS*13-1.00. Even though small amount of medium components were added to the basal medium, their inhibitory effect on cell aggregation made single-cell suspension cultures possible. Through fortification of several vitamins, final recombinant antibody concentration and specific antibody productivity were considerably enhanced. Srum-free formulation for a rCHO cell line can be used as a starting or basal serum-free medium for the development of highly effective cell culture bioprocess using recombinant CHO cells to produce recombinant pharmaceutical proteins. To modify basal protein-free medium, two statistical methods was utilized. Concentrations of vitamins and protein hydrolysates were optimized by using the experimental design method including the Plackett-Burman method. Through computer software, $Design-Expert^®$, optimal ratio of two components was predicted. 33 % of A and 67% of B were decided as proper ratio to enhance cell growth and recombinant antibody production. Effects of various culture temperature and pH on cell growth and protein production were investigated in the cultivation of $CS^*13-1.00$ cells. When culture temperature was shifted periodically between 37 ℃ and 33 ℃ every 24 hour, integral of viable cell density was increased significantly compared to the control at 37 ℃ at given pH conditions, resulting in increase of final concentration of recombinant antibody. Glucose uptake rate and lactate production rate increased in pH dependent manner as pH set value increased in a range of 6.8 to 7.2. When the pH was adjusted at pH 7.0 and 7.2 with a periodic shift of temperature, final antibody concentrations were 3.5 and 3.9-fold higher than the control, respectively. Also, When culture pH was shifted from 7.0 to 6.8, integral of viable cell density ...