The effect of different media composition and temperatures on the production of recombinant human growth hormone by CHO cells

Abstract

Cell lines derived from mammalian are dominant systems for the production of recombinant therapeutic proteins because of their capacity for correct protein folding, assembly and post-translational modification. In the search of an efficient method for the production of a recombinant protein using animal cell culture, we investigated the effects of different treatment including fetal calf serum concentration, glycerol and culture temperature on a Chinese hamster ovary (CHO) cell line on the production of recombinant human growth hormone (rhGH) and recombinant Chinese hamster ovary (rCHO) viability. The GH production was assessed using ELISA and western blotting methods and cell viability was determined by flow cytometry. The production of recombinant protein increased by 2-fold when stimulatory chemical such as glycerol was added in two stages, first cells were cultured without glycerol for a period of time in order to obtain enough cell density and then glycerol was added to achieve high specific productivity.. Moreover, glycerol addition increased cell viability. Low culture temperature (below 37°C) led to enhanced cellular productivity of the rhGH by 3-fold but decreased cell viability. These findings indicate that quite simple factors such as culture temperature and addition of simple chemicals may lead to the improvement of industrial process for the production of recombinant proteins such as rhGH.

Keywords: Cell viability; Chinese hamster ovary; Culture temperature; FCS; Glycerol; rhGH productivity.

Fig. 1

The effect of different treatments on the concentration of rhGH, produced by CHO. In all treatments, at day 8, media were collected by centrifugation of the cells. The level of rhGH assayed by ELISA; A: effect of FCS concentration, B: effect of glycerol addition and C: effect of temperature.

Fig. 2

Effect of FCS concentration on the cell viability. After growth in different FCS concentration, cell pellet stained with propidium iodide and cell viability was measured on the FL-2 channel by flow cytometer.

Fig. 3

Effect of glycerol and different temperature on cell viability. After growth in different condition, cell pellet stained with Propidium iodide and cell viability was measured on the FL-2 channel by flow cytometer.