Vitamin K-dependent protein production in transgenic animals.

Vitamin K-dependent proteins are currently purified from pooled human plasma or produced in mammalian cell culture systems by recombinant DNA technology. Transgenic animals may provide an additional expression system for the production of these therapeutic proteins. Mice have been used to test hybrid genes which direct the expression of recombinant factor IX and Protein C to the mammary gland. Transgenic livestock have also been created that secrete into milk fully active Protein C at 0.3 mg/mL, and factor IX at 0.2 mg/mL. Thus, it is feasible to develop genetically manipulated livestock for the industrial production of vitamin K-dependent proteins.