Improvement of IVCC and Increase of Productivity by Over-expression of bcl-xl Gene in Recombinant Cell Line

Abstract: Serum-free medium and chemical-defined medium are widely used for large-scale commercial production of therapeutic proteins. However， recombinant glycoproteins like coagulation factors and glycoprotein hormones are not expressed efficiently in these media. One of the most important reasons for this low productivity is due to apoptosis of cells during the cell culture process， which subsequently causes the low viable cell concentration and the short culture longevity. Over-expression of anti-apoptotic gene in the recombinant cells can improve IVCC (integral viable cell concentration)， and therefore， increase the productivity. In this study， bcl-xl gene was transferred into an established CHO-FSH cell line. CHO-FSH/Bcl-xL， a stable clone expressing Bcl-xL protein and the interested protein， was developed by screening high-producing clone and investigating its anti-apoptosis ability. Compared with the parental cell line， IVCC of the cell line over-expressing bcl-xl gene was 150%， and its productivity increased over 200%. These results demonstrated that expression of anti-apoptotic gene bcl-xl could alleviate apoptosis， enhance culture performance and increase productivity under serum-free suspension cell culture， which suggested that this strategy could be used for large-scale producing trace glycoproteins including coagulation factors and glycoprotein hormones in serum-free suspension conditions.

CSTR: 32200.14.cjcb.2012.07.0006