Artificial Prion Created

jabberjaw writes "Nature is reporting that researchers at the University of California San Diego have created a synthetic prion which, when injected into mice will bring about symptoms similar to those displayed by cattle suffering from bovine spongiform encephalopathy, aka mad cow disease. The researchers first crafted healthy prion proteins using bacteria. They then shook these proteins until they resembled the tangled structure of an unhealthy prion. Afterwords, these prions were injected into the brains of mice who fell ill two years later. Perhaps someone who is more familiar with this field of research would care to fill us in on the details as the article was rather light."

Comments

Wrong university...butu you've got it mostly right

[Anonymous Coward]

This was done at UCSF, not UCSD. Read the article

There are still a few people the dis-believe the prion theory of disease put forward by Pruisner. For those who aren't familiar with the subject, prions are essentially misfolded proteins that can induce their mis-folding by interacting with copies of themselves. So, if protein A become randomly misfolded into A', it can bump into other copies of A and induce them to form A'. In many of the disease cases, these misfolded proteins can form plaques or tangles which then disrupt or rupture and kill cells.

While Pruisner's evidence for such a mechanism is more or less overwhelming there were still a couple people who didn't buy the story. The experiment talked about here (and I haven't seen the actual paper yet, but look forward to reading it) is rather difficult to do and is pretty much the last nail in the coffin of those disagreeing with prion theory. They do complain that the protein activities of the mutants were really low and that the mice used were not of the ideal strain buut this is missing the forest through the trees. As far as all of us whose opinions matter are concerned, the case is no more than closed and the pro-Pruisner side has won.

BTW, I've heard Pruisner say that a lot of neurological diseases are really prion based...but that case is far from being closed...so keep your ears open for such discussions in the future.

-Devon (who should disclose that he's a neuro grad student at UCSF, but works on neurogenetic diseases and not prions)

A brief lesson on prions...

[theluckyleper]

Yes, I am a microbiologist, and I've done research on prions.

Basically, prions are proteins which are able to act upon other proteins and thereby create functional copies of themselves (identical copies are not needed). BSE (mad cow disease) and CJD (essentially the human version) are caused by 'rogue' prions which destroy tissue by converting large quantities of protein into more prions. Prions are basically the most elementary form of an infectious disease (as they are simply protein, no genetic material required).

Now, what these researchers have done is to prove that prions can spontaneously develop, without the need for viral or bacterial infection. Random changes in protein structure MAY result in prion creation. You needn't eat some mad cow (nor cannibalize some CJD gray matter) to contract CJD or some other prion-induced malady. Nor is a viral/bacterial infection required; the disease may develop spontaneously.

Hopefully this makes sense... I've had a few too many Schooners (beer).

Re:whoo hoo?

[mrfunnypants]

This is huge because it was still not very clear that Prions even existed. Many people in the field didn't agree with the very existence and this group has basically just proven that in fact proteins can cause disease. In the world if you had started sprouting off that proteins caused disease in as late as the 80's scientist would laugh and remove you from any future funding. Just to give you an idea, read this link at UCSD where Prions are discussed:

ucsd link

As for your question of how the disease works. Theories were made about how this was possible, dealing with stereochemistry of the prion proteins causing your natural protein to switch its stereochemistry to the unnatural state found within the Prions in a cascade effect resulting in death. It appears this group may have verified this theory.

Re:whoo hoo?

[BrokenHalo]

Am I way off base here?

Yes.

Prion diseases (to oversimplify a bit) are caused by incorrectly folded proteins that induce "correctly" folded proteins to assume the prion form. They are typically communicated by ingestion of meat (or meat products) from infected animals.

Bubonic plague is a bacterial infection by Yersinia pestis.