Gene transcription acceleration: main cause of hepatitis B surface antigen production improvement by dimethyl sulfoxide in the culture of Chinese hamster ovary cells

摘要

The production and specific productivity of hepatitis B surface antigen (HBsAg) in recombinant Chinese hamster ovary (CHO) cells were increased by 81% and threefold, respectively, when supplemented with 1.5% dimethyl sulfoxide (DMSO) in the culture medium. To investigate the mechanism of DMSO effect on HBsAg production improvement, HBsAg mRNA level was measured by real-time PCR. HBsAg mRNA was increased by about 1.5-fold at 1.5% DMSO. The increase could derive from the increase of HBsAg gene copy number, the improvement of HBsAg mRNA stability, or the acceleration of HBsAg gene transcription. It was found that HBsAg gene copy number was not significantly changed in the cells stimulated with DMSO. HBsAg mRNA stability of cells with DMSO treatment was also not obviously different from control, and the mRNA half-life of 5.58 h in the cells at 1.5% DMSO was comparable to that of 5.36 h in the control culture. DMSO resulted in 80% increase in HBsAg gene transcription activity assessed using a nuclear run-on transcription assay. It could be deduced that the acceleration of HBsAg gene transcription is the main cause of HBsAg production improvement. Biotechnol.