One advantage of using sheep to produce alpha-1-antitrypsin is that the product is produced in milk in large amounts.

• A. The product is produced in milk in large amounts
• B. It requires no ethical considerations
• C. It has no regulatory hurdles
• D. It is cheaper than all other methods

Answer: (A)

Using sheep as bioreactors for therapeutic proteins leverages the mammary gland to secrete the product directly into milk. Milk is produced in large volumes during lactation, so the amount of protein that can be harvested from a single animal is substantial. This setup makes it possible to scale up production more efficiently than many other methods, because you can obtain large quantities from the animals without resorting to expensive cell culture runs or complex downstream processing for each dose. The secreted protein in milk also allows relatively straightforward purification workflows from a single liquid source.

Additionally, expressing a human protein in a mammalian system helps support proper folding and post-translational modifications, which can be crucial for activity and stability of alpha-1-antitrypsin. Of course, there are ethical and regulatory considerations with animal-based production, and cost dynamics can vary with methods, but the hallmark advantage here is the ability to produce large amounts in milk.