Slashdot is powered by your submissions, so send in your scoop


Forgot your password?
Medicine Biotech

Prions Observed Jumping Species Barrier 214 writes "Nature is reporting on new findings that prions jump species barriers. Believed to be responsible for ailments such as Creutzfeld-Jakob disease and 'mad cow' disease, prions are thought to disrupt biological processes by causing normal proteins to fold abnormally. Researchers at the University of Texas Medical Branch in Galveston have observed infectious prions from hamsters causing abnormal protein development in mice, along with a range of other observations on prion actions in test tube environments. From the article: '... they also found that when a prion jumps species, it produces a new kind of prion. "This is very worrisome," says Claudio Soto, who led the research, published in Cell. "The universe of possible prions could be much larger than we thought."' Sounds like another good reason to donate your spare CPU cycles to projects like Folding@home."
This discussion has been archived. No new comments can be posted.

Prions Observed Jumping Species Barrier

Comments Filter:
  • Rudimentary (Score:1, Interesting)

    by retech ( 1228598 ) on Sunday September 07, 2008 @09:47PM (#24915413)
    Considering that we force feed cows and chickens the meat bi-products of the industry, we're actually causing a great deal of this to happen. In a perfect world we'd not feed herbivores rudiments and accelerate this type of process. But then again, garbage in garbage out, we deserve what we get.
  • The science of fear. (Score:2, Interesting)

    by Anonymous Coward on Sunday September 07, 2008 @10:25PM (#24915635)

    I work for one of Claudio Soto's former PhD students. From my brief skimming of this paper, it seems to be a simple proof-of-concept transmission between mice and hampsters. The discussion section, like a lot of science, is pure speculation - logical, but no need for slashdotters to scream "OMG we're all going to die!"

    I'm an avid MN deer hunter (and consumer...) and I've done a significant amount of work with PrP infected mice. While not worried about going crazy and having my brain melt in 15 years, I have quit giving blood to the Red Cross. In my opinion, nobody has any "28 days" type fears to raise.

  • by Anonymous Coward on Sunday September 07, 2008 @10:31PM (#24915673)

    i may have read the article wrong, but i'll give this a shot.

    you're right that we know that prions from cows can cause problems in humans. but i think what the article said is that it creates a new kind of prion as well. so where there used to be just one mis-folded protein messing with you, now there are two mis-folded proteins messing with you, and each is mis-folded in a different way and can do a different thing to you. so while you used to just have apples, now you have apples and oranges to deal with. two different fruits, with two different tastes. and you have to think that for every one instance where they caught this, they missed ten other instances. thinking of it that way, this could be huge.

    again, i haven't read the full article, and i may have read the synopsis wrong, but that's the impression i got out of it

  • by transporter_ii ( 986545 ) on Sunday September 07, 2008 @10:44PM (#24915767) Homepage

    I couple of years back, I did a lot of reading on Mad Cow. There were so many examples of it jumping the species barrier...and some of them many, many years old.

    Here is an example from 18 years ago:

    -=-=-= []

      WASHINGTON -- Eighteen years before last week's first confirmed case of mad cow disease in the United States, investigators concluded that an epidemic of a brain-wasting disease on a Wisconsin mink farm was probably caused by a malady similar to mad cow disease.

    The Wisconsin farmer had fed his mink a steady supply of "downer" cows -- too sick or injured to move on their own -- like the one that tested positive for mad cow disease in Washington state last week. On Tuesday, the Department of Agriculture banned such animals for human consumption.

    Long before the USDA action, the mink industry began discouraging farmers ..


    It is basically that anyone who did a little study would know that it could jump the species barrier...but it just can't do that until some people in white coats tell us it can do that...then it can.


  • Scary (Score:5, Interesting)

    by Pedrito ( 94783 ) on Sunday September 07, 2008 @10:53PM (#24915813)

    It made me wonder, if it changes when it jumps species, maybe prion diseases are something new, so I did some quick checking on Wikipedia. I didn't track down more stuff yet, but I plan on following up. I didn't realize this, but it appears that a lot of prion diseases are fairly recent developments. Scrapie showed up in 1732, Bovine Spongiform Encephalopathy in the 1800s, CJD showed up around 1920, Kuru in 1957, Chronic Wasting Disease in 1967, Feline Spongiform Enecephalopathy 1990.

    And these are more than half of the diseases caused by prions, I believe. That's more than a bit disconcerting.

  • by nido ( 102070 ) <{moc.oohay} {ta} {65odin}> on Sunday September 07, 2008 @10:53PM (#24915817) Homepage

    ... Mark Purdey [] was, of course, the British beef farmer who had a different theory about Mad Cow. In the 80's the British government required all cattle to be dosed with an Organo-phostate pesticide, to combat a warble fly epidemic (these bugs punch holes in cattle skin, making the hides less suitable for leather seats).

    Purdey was an organic farmer, and sued to protect his right to keep synthetic pesticides away from his herd. He won. A few years later Chernobyl went off, and some time after that the first Mad Cow epidemic occured. Purdey's cows were mostly immune. He had a few mad cows, but these were mostly transplants to his herd which had, presumably, been dosed with the pestacide.

    As the years went by, Purdey turned into a scientist himself, doing the research that the british government wouldn't do because of their potential liability in having caused the mad-cow epidemic (by require farmers to poison their herds).

    Basically, the pesticide used chellated (removed) copper from the treated body. Somehow manganese substitutes for copper, but it isn't a good subsitute. The radioactive fallout from Chernobyl didn't help things either. It's been years since I first read Purdey's site, so I don't remember the details.

    He commented that the Mad Cow in Washington (the northwest state) came from a copper-deficient pasture in Canada, into an area where quite a bit of nuclear weapons research had been done in decades past. The mad deer in Colorado also occupy a site with extensive radiologic environmental poisoning.

    So basically, Purdey's theory is that prions are an effect of environmental poisoning, not the cause of Mad-Cow-esque disease.

    Purdey is deceased now (brain cancer?), but his site's still live. Definitely recommended reading.

  • by jd ( 1658 ) <imipak AT yahoo DOT com> on Sunday September 07, 2008 @11:01PM (#24915861) Homepage Journal
    Prions appear to exist in a space somewhere between crystals (they "multiply" in a way mot dissimilar to crystals growing and do not make anything "new" the way a virus would) and the lower end of what is considered "true" life. This suggests to me that there is a continuum and that the terms "living" and "non-living" are not descriptive of anything fundamental. If that is correct, then I suspect we will find that prions were an important stage in getting to what we call "life". However, it is not obvious as to how you'd get from a free-floating RNA/DNA strand and a prion to a living cell, so there must be other stages in between, if that indeed was the sequence. I suspect that a study of prions could yield such an additional step, but only if the researchers are willing to accept such a stage could exist.
  • Is that surprising ? (Score:3, Interesting)

    by aepervius ( 535155 ) on Sunday September 07, 2008 @11:20PM (#24915939)
    Many of the proteins of the mammals are qu7ite in common except sometimes for a few details. If those few details make no difference to the attack site of the prion, it ain't that surprising that other similar brain protein can similarly badly in other mammals. Sooooo we should simply ban utterly to feed other dead mammals protein to other specy which are for human consumption (cue the sales of meat carcass into pet food....).
  • Re:Folding@Home (Score:3, Interesting)

    by Hal_Porter ( 817932 ) on Sunday September 07, 2008 @11:25PM (#24915963)

    It's like every /. article is an opportunity to espouse the same posts in a previous article. Let me save all the future posters their breathe...

    Dirty energy is bad.
    Global Warming.
    Creationists are dumb.
    DMCA is stoopid.
    OMG zero day is here!

    There, someone e-mail me when there's a comment worth reading.

    I think there's some inherent vulnerability of internet discussion sites to virulent memes. If you look at Digg at the moment it's got to the point where 50% of the stories on the front page are some dubious looking slur on Palin. A few months ago 50% of them where dubious looking slurs on Hilary. And a few months before that they were all posts containing that 09 F9 magic key. 4chan is plagued by self replicating javascripts because it doesn't have a CAPTCHA, but digg and slashdot get a different sort of replicator, one which needs human interaction to spread.

    It's like someone posts a meme, people mod/digg it up, there is a backlash, then more people digg it up and post it. People that disagree are eventually forced out. Eventually the meme uses up 50% of the bandwidth.

  • by Reziac ( 43301 ) * on Sunday September 07, 2008 @11:25PM (#24915967) Homepage Journal

    Yes, but now I'm wondering... DNA can be damaged/mutated by environmental factors; proteins can be damaged by chemicals (when I was in college, we used the crude method of boiling proteins in a saturated lye solution to break them down into their various amino acids); why should prions be immune?

    Which says nothing pro or con re this Purdey fellow's theory of the origin of BSE; he could be dead-wrong on that, yet correct as applied elsewhere. Or he may be completely off-base in every way, yet we should still look at *what* causes prions to "fold wrong"; who knows what we'll learn?

  • by vrjim ( 1287740 ) on Sunday September 07, 2008 @11:49PM (#24916103)
    Become a vegetarian and loose the risk of contracting a scary prion disease from your food. Prion diseases are awful- I'd take an STD or physical handicap any day over one of those. Now I understand that the USA only randomly checks 1% of cattle for mad cow disease. Since we HAVE had cattle found with it before that stands to reason that cattle with prion diseases have made it into the food supply. The scariest part is these prion diseases can have incubation periods in both cattle and humans for many years. If a cow does not show symptoms it is not likely to be checked for the disease even if it carries it. A tainted burger your parents bought you from McDonald's (containing meat from who knows how many different cows) when you were 10 might not show symptoms till you're 40+ and at that point how could anyone ever trace it to any particular time/place/meal? No- I'm not a vegetarian, but I am seriously considering dropping all animals from my diet except birds and fish.
  • by tfoss ( 203340 ) on Sunday September 07, 2008 @11:58PM (#24916147)

    Purdey's theory is that prions are an effect of environmental poisoning, not the cause of Mad-Cow-esque disease.

    First off, those two statements are unrelated. Prions can cause TSEs regardless of if copper or manganese from the environment causes them. Secondly, it is pretty well accepted by the scientific community that prions are the cause of TSEs. You can infect animals with PrP-Sc (the misfolded form of the prion protein (PrP-C being the normally folded version) and cause TSE. If you knock out the PrP protein, mice are not susceptible to PrP-Sc.

    What causes the first misfolding of PrP-C to PrP-Sc is unknown (unfortunately), and it is clear that PrP-C has copper-binding repeats, so an effect of Cu on the protein is a very likely possibility.


  • by Hal_Porter ( 817932 ) on Monday September 08, 2008 @12:16AM (#24916229)

    Have you heard of Cairn's-Smith's clay theory of abiogenesis []
    In simplified form, clay theory runs as follows: Clays form naturally from silicates in solution. Clay crystals, as other crystals, preserve their external formal arrangement as they grow, snap and grow further. Masses of clay crystals of a particular external form may happen to affect their environment in ways which affect their chances of further replication â" for example, a 'stickier' clay crystal is more likely to silt a stream bed, creating an environment conducive to further sedimentation. It is conceivable that such effects could extend to the creation of flat areas likely to be exposed to air, dry and turn to wind-borne dust, which could fall at random in other streams. Thus by simple, inorganic, physical processes, a selection environment might exist for the reproduction of clay crystals of the 'stickier' shape.

    There follows a process of natural selection for clay crystals which trap certain forms of molecules to their surfaces (those which enhance their replication potential). Quite complex proto-organic molecules can be catalysed by the surface properties of silicates. The final step occurs when these complex molecules perform a 'Genetic Takeover' from their clay 'vehicle', becoming an independent locus of replication - an evolutionary moment that might be understood as the first exaptation.

    Richard Dawkins said of this that he doesn't believe this particular theory of abiogenesis but something like this must have happened.

    He memorably said that one day a robot equivalent of Cairns Smith may note wryly that silicon based machines like him eventually took over from carbon based life like us that built them as tools in the same way that carbon based replicators took over from silicon based clay lifeforms that built them as tools.

  • by tloh ( 451585 ) on Monday September 08, 2008 @12:34AM (#24916313)
    mod parent up. I did some reading last year on Cronic Wasting Disease (CWD was mentioned in the article) for my infectious disease class and examples like the outbreak at the mink farm just mentioned was very prevalent in available literature. I think most people are getting the wrong idea because the article is badly written for a non-technical audience. The novelty seems *not* to be that prions can cause cross-species infections, but that it has been demonstrated in vitro (by way of "protein misfolding cyclic amplification (PMCA) protocol") in such a way that elucidated some details (multiple forms as revealed by novel strain properties) that were not apparent before. This is interesting *not* because it is a ground breaking new discovery, but because it serves as a starting point for further studying cross-species prion interaction from a different perspective using different techniques.
  • by vrjim ( 1287740 ) on Monday September 08, 2008 @10:47AM (#24919897)
    Since the incubation period in humans can be 50 years with an average 30 years (according to June 21, 2001 Wisconsin State Journal and some other sources I looked at) we likely have yet to see the extent of how many people were affected by the outbreak in the 80s. It's also easy to misdiagnose without proper testing- I imagine many doctors writing certain cases off as encephalitis or meningitis or a rapid onset of Alzheimer's (remember it sets in later in life due to the long incubation period) Yes, there are diseases you can get from vegetables, like salmonella, but unlike prion diseases you can destroy salmonella simply by cooking it. Prions aren't inactivated even by BOILING them. And though you can get Hepatitis A from consuming foods many of us have been vaccinated against it- not to mention the vast majority will fully recover from it in as little as 2 weeks with no permanent damage to the liver. Prion diseases on the other hand have no vaccine, no cure, and when they damage your brain you're damaged till death (which probably wont take much longer after).

"So why don't you make like a tree, and get outta here." -- Biff in "Back to the Future"