Transgenic cows making myelin basic protein
Myelin basic protein (MBP) is damaged in patients with multiple sclerosis. Transgenic cows, expressing the human myelin basic protein in their milk, may provide a large source of this protein. The protein would be extracted and purified from the milk before being given to patients as a therapeutic medicine.
Update: Dr Goetz Laible notes that funding for AgResearch’s biomedical research projects has finished. Dr Laible’s colleague, Medhat Al-Ghobashy, is continuing with the MBP research at Cairo University. In a paper published in 2017, Dr Al-Ghobashy reports that rhMBP from transgenic cow milk may have potential as a vaccine for MS. The research used mice and is still in preclinical applications.
Transcript
DR GOETZ LAIBLE The myelin basic protein is a protein that is only found in the central nervous system, and that has a role in insulating nerve fibres which conduct electrical signals. Now the application or the relevance of myelin basic protein is it is a major target when this insulation layer is coming under attack in some diseases. And, for example, in multiple sclerosis, patients are developing antibodies that attack their own insulating layers, and the main target is their… this myelin basic protein. And so if this insulating layer is destroyed, that destroys the conduction of these electrical signals in our nervous system. It has been shown, when this is given orally, it can lead to the suppression of the production of these specific antibodies that are responsible for attacking this particular protein in the nervous system.
Our project is really at the first step trying to provide a source for large quantities of this protein. Our strategy is to produce this protein in milk, because the mammary gland of a dairy cow can produce large amounts of protein, and it is easily accessible in large quantities. Now to do that, we are using regulatory sequences from bovine milk protein and just swap the core information for the actual protein for the human myelin basic protein. In that way, this myelin basic protein is now produced in the mammary gland and then is secreted into the milk and ends up with a new milk that now contains human myelin basic protein. In most instances, we would isolate this new protein out of the milk, so make it very pure, and then it can be used as a stand-alone drug to treat human diseases. That is the main approach. There might be opportunities to keep it in the context of the milk as a delivery system, but that is not an area that we are currently involved in.
Acknowledgements: Ann Lehman, Electron Microscope Facility, Trinity College Christchurch Radiology Group
