Researchers John Collinge and Giovanna Mallucci think that concentrating on “abnormal” prion levels in the brain is a wild goose chase. They created a strain of genetically mutated mice that lost their “normal” brain prions at 12 weeks of age.
When these mice and ordinary mice were both infected at birth with abnormal prions they all began to develop a CJD-like disease. But after 12 weeks, when the mutant mice lost their normal prions, the disease reversed – but continued to progress in the ordinary mice. Although abnormal prions carried on building up in their brains, the mutant mice recovered and remained healthy, whereas the control mice all died within two weeks.
These results suggest that abnormal prions themselves are not the problem – the problem is something to do with the conversion process between a normal prion and an abnormal prion. They conclude that there is a toxic intermediate stage that is the ultimate cause of CJD-like illnesses.
Coming next Halloween – Son of Prions!!! Hope you have a great time tonight Trick or Treating, everybody!
I heard a talk by Prusiner about prions back in 1993 or 94 or so (he won the 1997 Nobel prize for this). I have to say, he had a lot of energy and enthusiasm for the subject, but what he showed of data and evidence didn’t seem all that convincing. This is the sort of data that’s needed to really get into what’s going on here. It’s a very odd problem anyway…
…is that this article says the experimental mice all died in a matter of weeks. I was under the impression that prion infection took a LONG time to manifest – years, even. Maybe it’s different in mice?