Recombinant human factor IX produced from transgenic porcine milk

Area of Science:

• Biotechnology
• Biopharmaceutical Production
• Transgenic Animal Technology

Background:

• Conventional biopharmaceutical production faces challenges with complex proteins.
• Transgenic animal milk offers a promising alternative for cost-effective biomanufacturing.
• Recombinant human factor IX (rhFIX) is a critical therapeutic protein.

Purpose of the Study:

• To evaluate the production and purification of rhFIX from transgenic porcine milk.
• To characterize the physiological activity and properties of milk-derived rhFIX.
• To assess the potential of transgenic animals as bioreactors for biopharmaceutical manufacturing.

Main Methods:

• Utilized transgenic pigs with the bovine α-lactalbumin promoter to drive rhFIX expression in milk.
• Developed a three-column purification scheme following casein precipitation.
• Analyzed rhFIX characteristics including specific activity, Gla residue occupancy, isoelectric point, sialic acid content, and glycosylation/phosphorylation sites.

Main Results:

• Achieved rhFIX yields of 0.25 mg/mL from transgenic porcine milk.
• Purified rhFIX exhibited high specific activity and near-complete Gla domain occupancy (11.9/12 sites).
• Milk-derived rhFIX showed distinct properties from plasma-derived FIX (pdFIX) but retained similar glycosylation and phosphorylation patterns, with higher specific activity.

Conclusions:

• rhFIX produced in transgenic porcine milk is physiologically active.
• Transgenic animals serve as effective bioreactors for industrial-scale biopharmaceutical production.
• This method provides a viable and cost-effective approach for complex protein manufacturing.