High-level Production Of Human TNFR-Fc Fusion Protein In CHO Cells

Based on these pharmacological advantages about 70% of therapeutically active proteins which are on the market or under clinical development are produced by mammalian cell cultures. Mammalian cell expression system has become the dominant system for biopharmaceutical production due to their capacity for proper protein folding and post-translational modifications. Chinese hamster ovary cell /DHFR~- (CHO/ DHFR~-) and the amplifiable marker DHFR(dihydrofolate reductase) are routinely used to established cell lines that produce useful amounts of protein because of genotypical stabilization of engineering cell line, stable and high expression level of heterogeneous genes, proper post-translational modifications, secretion of expressed proteins, adherent and suspension culture. The expressing level of heterogeneous genes mainly depends on the design of vector, heterogeneous gene, integraton site and copy of number of inserted gene, screening of positive cell line, hose cell and culture.To increase the expressed level of extracellular domain of human tumor necrosis factor receptor-II-IgG Fc(TNFR-Fc) fusion proein in CHO/ DHFR~- cells via weakening the transcription of DHFR gene. We modified the dual expression vector pTandem-1 to constructed two bicistronic expression vectors(pT-dhfr1-TRFc and pT-dhfr2-TRFc ), which were inserted by the TNFR-Fc fusion protein...