Recombinant Expression of Complex Proteins in Human Cell Lines

Coagulation factors, as factor VII, VIII, and IX, are complex proteins which are very difficult to express. Blood coagulation factor IX is a vitamin K-dependent protein, and it has become a valuable biopharmaceutical in the treatment of hemophilia B. Here, we describe the techniques used to generate human cell lines producing human recombinant factor IX, as an example of complex protein, as well as in vitro characterization of this coagulation factor.To produce the FIX human adherent 293T SK-Hep-1 cells were used and stably modified by a lentiviral vector carrying the hFIX and the eGFP genes. The eGFP was employed as a reporter protein.