Edinburgh hatches new drug hopes in hen eggs

Edinburgh’s strong animal science sector has produced another innovation – genetically modified chickens that can lay eggs that contain human proteins used in drugs for arthritis and some cancers.

The Roslin Institute at Edinburgh University – where the world’s first cloned mammal, Dolly the sheep, was created – says that the drugs are 100 times cheaper to produce when laid than when manufactured in factories.

We are not yet producing medicines for people, but this study shows that chickens are commercially viable for producing proteins suitable for drug discovery studies and other applications in biotechnology,” says Professor Helen Sang.

The Roslin Institute is a world-leading institute for animal science research, part of Scotland’s leading knowledge hub in animal, veterinary, and biological sciences. Scotland has the largest cluster of animal bioscience/aquaculture researchers in Europe, with over 1,000 active researchers. The country is recognised as a leading player in animal health, particularly in the fields of genetics, genomics and proteomics, endemic disease research and ruminant parasitology.

The Roslin Institute has helped generate annual productivity gains of £247 million through its breeding and genetics research, while Scotland’s Easter Bush Research Consortium is one of the world’s largest animal health research groups.

While Scotland is renowned for vaccines developed for sheep and cattle, this latest discovery holds promise for human therapeutics in the future.

Many diseases are caused because the body does not naturally produce enough of a certain chemical or protein. Such diseases can be controlled with drugs that contain the deficient protein, but producing these drugs synthetically can be very expensive.

Dr Lissa Herron, Head of the Avian Biopharming Business Unit at Roslin Technologies, and her colleagues managed to reduce the costs by inserting a human gene – which normally produces the protein in humans – into the part of the chickens’ DNA involved with producing the white in the chickens’ eggs.

The team has focused on two proteins that are essential to the immune system: IFNalpha2a, which has powerful antiviral and anti-cancer effects; and macrophage-CSF, which is being developed as a therapy that stimulates damaged tissues to repair themselves.

Three eggs are enough to produce a dose of the drug, and chickens can lay up to 300 eggs per year. With enough chickens, the researchers believe they can produce drugs in commercial quantities. Dr Herron says the research observed no adverse effects on the chickens themselves, which lay eggs as normal.

Eggs are already used for growing viruses that are used as vaccines, such as the flu jab. This new approach is different because the therapeutic proteins are encoded in the chicken’s DNA and produced as part of the egg white. Scientists have previously shown that genetically modified goats, rabbits and chickens can be used to produce protein therapies in their milk or eggs. The researchers say their new approach is more efficient, produces better yields and is more cost-effective than these previous attempts.

The development of drugs for human health, and the regulation required, will take between 10 and 20 years.

The researchers are also hopeful of using chickens to develop drugs for animal health. These include: drugs which boost the immune systems of farm animals as an alternative to antibiotics; and using the healing properties of macrophage-CSF to treat pets, such as regenerating the liver or the kidneys of a pet that has suffered damage to these organs.


via: The Roslin Institute, Life Sciences Scotland, BBC News