August 01, 2015

 

 Mutation protected mice in study against prion disease

Posted July 15, 2015 

A prion protein mutation gave laboratory mice protection against several prion diseases, according to one study’s results.

Those results, published online June 10 in the journal Nature, indicate transgenic mice that expressed a novel human prion protein variant were resistant to Creutzfeldt-Jakob disease, variant CJD, and kuru, all of which are degenerative neurologic diseases. The article, “A naturally occurring variant of the human prion protein completely prevents prion disease,” is available here

The researchers found the variant while studying survivors of a kuru epidemic that occurred in the 1950s among the Fore people of Papua New Guinea’s highlands, according to an announcement from the Medical Research Council Prion Unit at the University College London Institute of Neurology. All of the authors are affiliated with the Prion Unit. 

The Fore had eaten their dead as a sign of respect, leading to the epidemic. The researchers found the novel prion protein in some survivors and engineered the same genetic change in mice.

In the announcement, Dr. Emman­uel A. Asante, who led the team that produced the mice, said the genetic engineering was expected to provide some disease resistance.  

“However, we were surprised that the mice were completely protected from all human prion strains,” he said. “The result could not have been clearer or more dramatic.”  

John Collinge, MD, unit director and leader of the kuru research program, called the mutation “a striking example of Darwinian evolution in humans.” The epidemic selected for a genetic change that provided full protection against invariably fatal dementia, he said.

“Much work is now ongoing in the unit to understand the molecular basis of this effect, which we expect to provide key insights into how seeds of other misshapen proteins develop in the brain and cause the common forms of dementia, thereby guiding us to new treatments in the years ahead,” he said.