Swedish researchers recently offered the most conclusive evidence to date that diseases such as Creutzfeldt-Jakob, scrapie and BSE are caused when abnormally shaped prions attach themselves to normal prions and cause the normal prions to become misshapen as well.
Although this is the method by which such diseases were believed to develop, this process had never actually be observed in animals. Researcher at the University Hospital Zurich in Switzerland set out to demonstrate this process in mice.
First, they created a genetically modified strain of mice that expressed an artificial prion that was easily distinguishable from other tissues (distinguishing prions from other tissue is otherwise a very difficult task).
Then, they exposed the mice to prion proteins responsible for scrapie in sheep. As they expected, the diseases prions attached themselves to the artificial prions in the mice.
But here’s the real kicker — the diseased prions took much longer to transform the artificial prions into diseased prions. The genetically modified mice survived almost three months longer than a non-modified control group when exposed to the scrapie prions.
Current research into treating CJD and others such diseases is focused on antibodies to create an immune response to the misshapen prions, but this finding suggests that another area to investigate will be the possibility of altering normal prions so they resist the efforts of the diseased prions.
Source:
Study Hints at Way to Treat ‘Mad Cow,’ Related Ills. Reuters, April 3, 2003.
Prion principle proved. Helen Pearson, Nature, April 4, 2003.