Scientists genetically modify hens to produce illness-curing protein
Scientists in Japan may have found a way to produce cheaper drugs that could be used to treat a range of diseases from chicken eggs.
They have successfully genetically modified hens to produce eggs containing large amounts of interferon beta protein, a protein used to treat various illnesses, including multiple sclerosis and cancer.
The protein is very expensive, costing between US$300-US$1000 for just one microgram, according to pharmaceutical company, Cosmo Bio who co-led the research.
For treating MS, for example, the interferon dosage can start at 30 micrograms and increase from there.
The research was jointly conducted by scientists from the National Institute of Advanced Industrial Science and Technology (AIST), the National Agriculture and Food Research Organization and Cosmo Bio.
According to Mika Kitahara, a spokesperson for Cosmo Bio, this technology will reduce the price of cancer drugs at least by 90% if proven successful in further trials.
The conventional production of interferon needs large aseptic (sterile) facilities, but eggs work as a protein-producing aseptic system, said Kitahara.
Isao Oishi, chief researcher from the cell and molecule mechanism research group at AIST said the research was conducted to test whether the eggs from genetically modified chickens can be used for cheap production of these proteins.
A range of biological systems can be used to try and create drugs, such as bacteria, yeast and some mammalian cells, but “some proteins just don’t suit these systems,” said Professor Helen Sang from the Roslin Institute at the University of Edinburgh in the UK. For those that don’t quite work, “making protein from egg-white is relatively easy,” she told CNN.
“Interferon was discovered as a cell-signaling protein molecule in the body which acts against viruses,” said Dr. Robert Bermel, director of the Mellen Center for Multiple Sclerosis at the Cleveland Clinic Neurological Institute. Later it was used to treat auto-immune diseases — where a person’s immune system attacks their body — like multiple sclerosis, he adds.
Multiple Sclerosis (MS) affects the brain, spinal cord and eyes, resulting in a range of symptoms, such as vision problems, numbness and difficulties walking.
Bermel explained that interferon protein molecule is expensive because manufacturing it is a tedious process requiring strict quality control.
“Interferon for MS can be manufactured from bacteria like insulin or from Chinese hamster ovary cells.” The quantity of interferon produced this way, however, is very little. “(The new research) sounds like a relatively inexpensive way to mass produce it,” he says.
Previously, the Japanese scientists tried to produce the modified protein by inserting the required genes into chicken chromosomes using a virus as a vector, but said this produced an “irregular result.” The new method aims to more accurately and stably produce the protein by knocking in edited genes, using a gene-editing tool called CRISPR. The researchers are currently writing up their findings for academic publication.
More research is needed and the interferon beta protein will need safety clearance through trials before it can be used to treat patients.
However, Sang explained it’s not as simple as modifying these chickens to get endless supplies of the drug at a lower cost.
“You’ll have to show (the drug) is exactly the same as the drugs that have gone through all the clinical trials,” said Sang, whose own team has been working on transgenic chickens for over a decade. As well as simply making the drugs in the eggs, they will also need to be purified and validated through additional research, she said.
If this new source of interferon is shown to be the same, structurally, “then there is a lot of advantage in terms of scale,” said Sang. You can start with a few hens then scale up quickly, she said.
One drug, Kanuma, produced using modified chickens has already been approved by the US Food and Drug Administration to treat Lysosomal Acid Lipase Deficiency, a rare inherited condition where the body does not produce enough of a protein that helps the body break down fatty material.
The immediate hope is for the cancer-battling medicine to result in affordable medical products. The team is looking forward as well, with research underway to produce human antibodies using the same method.
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