Serum-Free Suspension Cultured Human Cells Can Produce A High-Level Of Recombinant Human Erythropoietin

Currently, the majority of commercial recombinant therapeutic proteins are produced in nonhuman expression systems. Human cells are capable of producing recombinant proteins with post-translational modifications that are more similar to native proteins which reduce immunogenicity. This article describes the potential of the human cell lines Sk-Hep-1, HKB-11, and Huh-7, cultured in serum-free suspension conditions, to produce a complex recombinant glycoprotein, human erythropoietin (EPO). Recombinant cell lines were generated by lentiviral transduction and sorted by flow cytometry. All the recombinant cells presented high-specific cell growth rates and a high level of rhEPO production. Maximum rhEPO concentrations achieved by Sk-Hep-1, HKB-11, and Huh-7 cells were 112.5 mu g/mL, 112.7 mu g/mL, and 571 mu g/mL, respectively. The levels of rhEPO production by Huh-7 cells were higher than the levels commonly reported in the literature for serum-free suspension cultures. The rhEPO produced demonstrated biological activity measured through in vitro differentiation of CD34+ cells. In view of this, we demonstrate that Sk-Hep-1, HKB-11, and Huh-7 cell lines have good characteristics to be used as host cells for the production of complex recombinant glycoproteins, with special emphasis on Huh-7 due to enhanced EPO production.