Scientists have successfully managed to produce human proteins, which could one day be used in medicines, in a rather unconventional way – they got chickens to lay eggs containing them.
Publishing their findings in BMC Biotechnology, a team from the University of Edinburgh genetically modified hens so that they produced two kinds of human protein in their eggs. The proteins were IFNalpha2a, which has both anti-cancer and anti-viral properties, and macrophage-CSF, which is being developed as a therapy to trigger damaged tissue to repair itself. The pig version of the latter was also produced.
A sufficient dose of protein was produced in the white of just three eggs – hens can lay up to 300 a year.
Certain kinds of drugs rely on human proteins, which, unsurprisingly, can be both costly and time-consuming to artificially produce. At the moment, these proteins are produced by mammalian cells that have been cultured in the lab, so a simpler solution is very desirable.
"You need a living system to manufacture them because proteins are very large molecules, very complex and they need all of the machinery of a cell to make them and fold them properly," lead author Dr Lissa Herron told BBC News.
Scientists have already managed to produce human proteins in eggs – for example, a Japanese team got chickens to lay eggs containing a protein that can be used to treat MS last year, but the researchers behind the latest study say their approach is more efficient, produces better yields, and is cheaper than previous techniques.
Right now, the proteins produced by the hens won’t actually be used in medicines given to patients, but in future, they could be. The current study just proves that the idea is feasible, and that the design works, but more research will be needed before the proteins produced by these GM chickens can actually be used clinically. They could also be used to create veterinary drugs to treat livestock and for research purposes too.
The researchers also keep cockerels, allowing their GM hens to reproduce and create the next generations of transgenic chickens.
"If you want more eggs you just need more birds," Herron told BBC News. "So we can produce a lot of hens in a short period if we want to bulk up the supply of the drug."
If you’re worried about the chickens’ welfare – the genetic modification has no impact on their health or wellbeing, and they live in nicer conditions than much of the poultry we farm for meat and eggs.
"We are excited to develop this technology to its full potential, not just for human therapeutics in the future but also in the fields of research and animal health," Herron said in a statement.