earticle

영어

Due to the need for a faster and cheaper approach for therapeutic protein production, Transient gene expression (TGE) system has been highlighted. TGE can also serve as a rapid mammalian protein expression system for the evaluation of therapeutic protein candidates and subsequent high-throughput screening, without the lengthy time periods and resources required for stable cell line development. While CHO cells have been the most widely used mammalian host in the field of biotechnology industry, TGE in CHO cells has been hampered by low titers. In this report, episomal plasmid replication in CHO cells was accomplished by the use of polyomavirus large T-antigen (PyLT)/ori system. CHO DG44 cell line was stably tranasfected with the PyLT gene and Polyomavirus origin was inserted to expression vector for autonomous replication. Also, Epstein-Barr Virus nuclear antigen-1 and OriP were encoded in expression vector for plasmid retention. With PyLT/ori system, CHO cells were engineered to inducibly overexpress anti apoptotic protein Bcl-xL using the doxycycline Tet-off system. Culture longevity was enhanced by overexpression of Bcl-xL in fed-batch culture and under NaBu added condition causing enhancement of a recombinant protein production. The results demonstrate the use of Bcl-xL was combined with the PyLT/ori system can enhance the production of recombinant protein by transient expression in CHO cells.