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Crocodile's Immune System Kills HIV

ASEville writes "In an ongoing effort to stop the spread of HIV, scientists in Australia have discovered that crocodiles can fight off HIV and kill the virus. This is a major boon to medicine because the crocodile serum can also fight things that are penicillin resistant such as staphylococcus aureus."

33 of 628 comments (clear)

  1. What a hack by Stickerboy · · Score: 5, Informative
    "The scientists hope to collect enough crocodile blood to isolate the powerful antibodies and eventually develop an antibiotic for use by humans."

    Antibiotics kill living bacteria. There isn't a single antibiotic that can disable a virus (like HIV), which isn't even alive.

    The scientists probably hope to use modified crocodile immunoglobulin the same way we use animal-developed immunoglobulin as a tetanus antitoxin for patients who haven't been immunized... kind of a booster shot for patients fighting an HIV infection. The problem with animal-developed antibodies is that the human body recognizes them as foreign, and soon starts to mount an immune response against them as well.

    --
    Light a fire for a man and he'll be warm for a day. Light a man on fire and he'll be warm for the rest of his life.
  2. not what it's cracked up to be by larry+bagina · · Score: 4, Informative
    I'll reserve a real judgement for when more information is published in Nature or Science, but it doesn't appear to be anything useful.

    The human immune system is fully capable of killing HIV. However (dumbed down enough for Reuters readers) HIV infects T4 Lymphocytes, so killing the virus means killing your own immune system, and you die of obscure diseases.

    The antibacterial angle sounds promising, though.

    --
    Do you even lift?

    These aren't the 'roids you're looking for.

    1. Re:not what it's cracked up to be by Anonymous Coward · · Score: 3, Informative

      How the hell is it promising ? HIV is a virus not a bacteria, antibiotics won't do shit against it. You need to kill CD4+ cells that harbor the virus but guess what Sherlock, they die in abot 1.5 days after infection anyway. And even if you figure out how to kill the cells you still don't know which ones to kill because memory T cell contain HIV in latent state ! Bwahahaha ! You better hope you got d32 mutation in your CCR5 receptors because crocodile 'serum' is a crock of shit

    2. Re:not what it's cracked up to be by Anonymous Coward · · Score: 4, Informative

      The body CAN indeed kill HIV however it can't completely eredicate it. But it comes closer than you seem to think.

      When a person becomes infected with HIV, the amount of virus in the blood explodes - it goes from 0 zero copies per mL to several million copies per mL. This triggers an immune reaction (which is why a large percentage of patients get flu-like symptoms during the earliest stages of infection). But guess what, after a few additional more weeks the body has sort of taken control and the viral load drops so low that it is undetectable (and we can measure down to a few hundred copies per mL). The initial symptoms go away and for some period of time it may be impossible to give any direct evidence of the infection. Note that this is what occurs with treatment of any kind!
      HIV-tests detect the body's own antibodies against HIV but it may not be possible to detect the virus itself.

      Replication must however continue to occur on a low level because over the years most HIV patients experience a steady decline of CD4+ cells, the cells that HIV most frequently infects. After some time this decline starts to accelerate until the CD4+ count is so low the patient gets sick from all kinds of diseases.

      It is not known exactly what is the cause of this decline. It seems weird that the body can fight off the virus at millions of copies per mL without suffering much damage while the last bit of replication (probably caused by latently infected cells) is so damaging. One thing that is known is that the CD4+ cells do not die as a direct result of being infected with HIV. In fact it is a very small percentage of CD4+ cells that are infected at any given time. CD4+ cells may be dying because of apoptosis (cellular suicide) triggered in some way by chemicals in the blood stream or actions of other cells infected with HIV. The hole flow from HIV infection to AIDS also involves certian mutations taking place in the virus' gene. It may be these mutation that causes the accelerated decline but the causation may also be the other way around.

    3. Re:not what it's cracked up to be by CrackedButter · · Score: 2, Informative

      You may not be a biologist but your post was put together coherently enough for me to read it because you made it sound so interesting. I hope you get modded as appropreiate.

  3. Mod down yet Another Misleading Slashdot commentor by Anonymous Coward · · Score: 5, Informative
    "There is nothing in the article to suggest that they have isolated the specific component that kills HIV, let alone determined that it is safe for human injection."

    I know the /. commentor's don't read the articles submitted all the way to the end, so here's a bit towards the end that really matters:

    "The scientists hope to collect enough crocodile blood to isolate the powerful antibodies and eventually develop an antibiotic for use by humans ... There is a lot of work to be done. It may take years before we can get to the stage where we have something to market," said Britton.
  4. Re:HIV-AIDS by FidelCatsro · · Score: 2, Informative

    To put it very simply.
    HIV is a retrovirus which attacks and weakens the immune system immensely , AIDS is a syndrome resulting from an acquired deficiency of the immune system.

    --
    The only things certain in war are Propaganda and Death. You can never be sure which is which though
  5. Re:HIV-AIDS by nietsch · · Score: 4, Informative

    The hypothesis that aids is not caused by hiv has been very thoroughly disproven AFAIK. The (probable) reason one 'scientist' kept claiming that was because it made him 'famous'. Other parties that wanted to deny AIDS for political resons kept supporting this guy or held on to his theories. I can't remember his name.

    As for funding: Would you give funding to 'scientists' that claimed the earth was flat or created in 7 days with no evolution? Lunatics don't get money because they are lunatics, not because their ideas need to be suppresed by gouvernment.

    There are more countries in the world doing AIDS research than the US, so any errors caused by your strange funding policy would be quickly corrected in the rest of the world. The first breaktrough successes were made in Europe(france) IIRC.

    As for the causes of death with AIDS: that is what you get when AIDS takes out your immune system: you die of the first petty illness that comes along.

    So this 'AIDS is not caused by HIV' meme is nothing but FUD, please don't spread it any further.

    --
    This space is intentionally staring blankly at you
  6. Re:Research Quality by Joel+from+Sydney · · Score: 2, Informative

    How many large academic institutions do you think would be happy to have crocodiles running around? Or perhaps the research centre is backed by a large (unnamed) academic institution!

    Don't be so quick to assume that things must be wrong because they seem unusual to you.

  7. Re:This research... by mister_tim · · Score: 2, Informative

    Informative?

    Silly mods need to watch more Monty Python, or do we need a sheep dip reference to get them to understand. Maybe if we mentioned that Prof Wilkins first name is Bruce...

  8. Re:Sing with me by Tmack · · Score: 3, Informative
    Too many people probly dont know the reference, so here is a link to all you need to know...
    Schnappie, das kleine Krokodil
    Amusing, even if you dont know german, more so if you do.

    Brief descript for the lazy non-clicker types: German kids webpage (tv show too?) with an animated crocodile as the main character that likes to sing/dance/etc. Think of an animated version of Barney the purple dinosaur where barney is a little green croc instead.

    tm

    --
    Support TBI Research: http://www.raisinhope.org
  9. Human immunity has been discovered before... by Gopal.V · · Score: 3, Informative
    > There are lots of known chemicals that kill HIV. The trick is finding one that leaves the patient alive.

    A study in 2000 proved that 3 South African prostitutes were resistant to HIV strains from the region. They also found a significant group of kenyan prostitutes with relative immunities to small doses of HIV virii. Interestingly as soon as the women started getting money from the researchers for co-operation with the studies, they lost their immunity.

    Should it come as a surprise that the Human immunodeficency virus is killed by something in crocodile serum ?. There are things in the human blood stream which can kill off HIV, but most of us lack these mutated T-cells (which are killed off by the normal cells) in sufficent quantity to beat the infection completely.
  10. Re:If I remember...... by Dunbal · · Score: 3, Informative

    HIV is a peculiar strand of virii not taking one specific form but that of multiple forms that are ever changing..

          You are correct. This retrovirus depends on an enzyme called reverse transcriptase to convert its RNA to DNA, which is then used by our cells to make more copies of the virus. Unfortunately this enzyme is not at all efficient and makes very poor copies. This means there is an extremely high mutation rate. The good side of this being HIV becomes a very slow infection and doesn't kill you in a matter of days wiping out your entire immune system. The bad side is that the mutation rate is phenomenal over time, and strains of HIV with drug resistant reverse transcriptase are becoming more and more common.

          Part of the problem with the actual AIDS illness is that the patient not only has a compromised immune system due to a low CD4 T-cell count, but the little bit of immune system s/he has left is busy making thousands of useless antibodies to all the different mutated proteins the virus made over the years. It gets you both coming AND going...

    --
    Seven puppies were harmed during the making of this post.
  11. Re:evolution by michaeldot · · Score: 2, Informative

    What do you mean? The croc is probably the closest thing to a dinosaur still alive today. (Birds, though descended from dinosaurs, have grown feathers and stuff.) That's less evolution, isn't it?

  12. Quick, damage control! by krayzkrok · · Score: 5, Informative

    Ho, never thought I'd be the subject of a Slashdot news report.
    Time to clarify things.
    TFA contains a number of errors. First the statement I made about HIV is true, but as others have pointed out it does not mean we've found the cure for AIDS. It simply means that we've compared alligator serum and human serum and found the former significantly more effective at killing the HIV virus than human serum. It was intended to illustrate the overall efficacy of the crocodile / alligator immune system, that was all.
    Second, these are not antibodies. Croc immune system works primarily through the innate or complement system, which does not involve antibodies. It's a simpler and more primitive immune response than the adaptive immune system that is key for mammals, but the advantage is that it's very direct and hence difficult for bacteria etc to evolve resistance to. It's "primitive" nature may be behind its effectiveness.
    The main finding here is that the alligator / crocodile immune system is far more effective at killing a wider range of bacteria (gram +ve and gram -ve), viruses and fungi than our own immune system. When you've evolved over 235 million years, and your daily social behaviour involves biting limbs off other crocs, you need a good immune system! It clearly has potential medical implications down the line, but that's a long way off yet. First we have to fully understand what makes croc immunity tick. We are still trying to purify a protein which we believe is an antimicrobial peptide, but hopefully that will happen very soon after this recent work.
    Eventually if anything does come of this, and we can isolate a "factor" that has human medical implications (and is safe for humans, unlike the far more effective chlorine bleach) it would indeed be synthesised. Adam Britton

    1. Re:Quick, damage control! by krayzkrok · · Score: 5, Informative

      This isn't my theory, and I can't seem to pull the appropriate citation up for you, but the gist of the paper was that the innate immune system is very much a secondary response in humans and hence has always been viewed as "primitive" (hence the quotes). Reptiles (and some other groups including fish) never developed a particularly effective adaptive immune response like mammals, but instead their innate immune system naturally evolved over time to become more effective than the innate system in mammals. The main advantage of the innate response seems to be its non-specificity. The results we're seeing in alligators, crocs, sharks etc seem to bear this out to a degree. Inferior? There's no such thing, in my opinion - each system is well-adapted for each user even though it's never perfect. If it was we'd never fall ill. So perhaps we can cheat a little and steal the good bits from our (very) distant relatives...?

      Adam Britton

  13. Re:Crocodile Spam by krayzkrok · · Score: 5, Informative

    This scam fed off our initial pilot study findings, back in 1998. There was worldwide media exposure at the time because of the demonstrated ability of the croc serum against antibiotic-resistant bacteria (S. aureus). They used this media coverage in a weak attempt to add credibility to their product.

    Yes, we have tried suing them (mainly for defamation, because they claim we endorse this crap) but it's very difficult to sue companies that apparently don't exist.

    Adam Britton

  14. Re:Yet Another Misleading Slashdot Summary by EvilSS · · Score: 3, Informative

    Odd phrasing aside, this research has been going on for a while. They have isolated one protein that has proven to be a very powerful antibiotic. My guess is they may have found or are trying to isolate another that functions as an anti-viral.

    Oddly enough, the research started when someone decided to look into why crocodiles, who get injured all the time in fights and live in muck, never seemed to get infections from their injuries.

    --
    I browse on +1 so AC's need not respond, I won't see it.
  15. Re:Research Quality by krayzkrok · · Score: 5, Informative

    Er, why is research only valid if it comes from an academic institution? Crocodylus Park (the name for the facility run by Wildlife Management International, of which I am an employee) is run by professional biologists who just happen to also run a tourism faclitity to get science across to the public. The fact that we're private doesn't have anything to do with the quality of our research - we still publish in peer-reviewed journals so it's open to international scrutiny like any other research.

    We're also collaborating with McNeese State University in Louisiana for this project.

    Adam Britton

  16. Re:Antibodies.... or not? by krayzkrok · · Score: 5, Informative

    Correct, this is what we're talking about primarily. The news article was wildly inaccurate and embarrassing to read quite frankly!

    We don't talk about defensins because we're not sure yet that defensins are involved. We suspect they are, but until we purify and sequence the proteins we're looking at we can't be sure. Hopefully this is only weeks away.

  17. Re:Yeah that cloaca is a two-way street too... by SteveAyre · · Score: 2, Informative

    Latin for 'Sewer' just to give a nice mental image...

  18. Re:Yet Another Misleading Slashdot Summary by krayzkrok · · Score: 5, Informative

    Well Mr Angostura, you're as bitter as your namesake aren't you?
    First of all, if it isn't clear that this news report is crammed full of factual errors, then perhaps it isn't obvious that what I said may have been completely misquoted? After all, the guy almost had me describing a new type of "crocodile antibodies"! This was "quoted" from a phone interview where I could hear the journalist typing in the background, so it's hardly a direct quote. The only part I definitely said word for word was the "gun to the head" line.
    And I'm not Australian, by the way (not yet at least) so I have no idea how to operate a sheep dip.
    Yes, we did discover an antimicrobial peptide (probably a defensin) several years ago. This is a continuation of that research.

    Adam Britton

  19. Yes it Does Matter by BioCS.Nerd · · Score: 2, Informative

    It matters. When you inject a foreign protein (or most anything for that matter) in your body you mount a defense to it. This can lead to flu-like symptoms and flat out rejection of the treatment. Even when you have HIV your immune system is still kicking around albeit in a weaker state. The last thing you need is to deal with HIV and some foreign protein.

    What will probably happen with this knowledge, assume it's viable, is the generation of chimeric antibodies, i.e. those with human and non-human components. What happens is you take the active bits of the non-human anbtibodies, find the gene, and then insert that into a human antibody gene. This gene is then expressed in some eukaryotic critter, e.g. yeast. The end result is that you can largely bypass the problems of the body mounting a defense against the antibody because it mostly looks natural. Pretty cool, eh?

    In case you're wondering, yes this approach could work. HIV attacks the part of your immune system that mounts a defense (the cells that say "Hey, I remember this. This is how we fixed the problem last time" -- the exact cell name escapes me at this point in time), not the antibodies themselves.

  20. I don't see why this is so special. by Andy+Dodd · · Score: 2, Informative

    HIV - HUMAN Immunodeficiency Virus

    There are a number of forms of *IV - Most of them have major trouble jumping species. Good immune system or not, a virus that affects humans is going to have serious troubles infecting another species, especially a reptile. Many such virii have trouble even jumping between closely related species. (HIV vs. SIV)

    This holds true for a number of other virii - Take Ebola Reston for example. Deadly to primates, but can't infect humans. Same for SIV (Simian Immunodeficiency Virus). Most of the time SIV can't take hold in a human. (Although once or twice it has, and HIV evolved from there.)

    --
    retrorocket.o not found, launch anyway?
    1. Re:I don't see why this is so special. by PakProtector · · Score: 2, Informative

      Ebola Reston can infect humans, and was found to circulate in the blood of atleast four humans who came into contact with it (two workers at the Monkey House and 2 workers at USAMRIID) several months after the event.

      It's not that Reston doesn't infect humans, it's just that Reston doesn't seem to do anything to humans.

      --

      Edward@Tomato - /home/Edward/ man woman
      man: no entry for woman in the manual.
      "Qua!?"

  21. Re:Yet Another Misleading Slashdot Summary by krayzkrok · · Score: 5, Informative

    One final comment on this - I need to vent! Bear in mind that these news reports are *way* off the mark in their reporting. The vast majority simply copied the Reuters article and diluted the facts yet further.

    It was Reuters who picked up on the HIV aspect and blew it out of proportion. It was never the goal of the study to combat HIV - it was just an interesting test. They even managed to misquote me almost completely. The main focus has been the antibacterial properties of the blood.

    Also, the part about the immune system being "too powerful" is something they pulled out of their cloaca. We're quite aware, as scientists, that it's far too early to start talking about marketable antibacterial drugs. The various factors that provide crocs with their powerful immune systems may not have any safe human medical use whatsoever. The fact that they *could*, however, is obviously interesting, but too many people here are taking this dodgy news report too literally. Don't get me wrong - this is exciting stuff and it could have health benefits down the line, but I don't like seeing this work getting misrepresented like this.

    There are peer-reviewed papers out there (check Merchant, principal author) and this work is being written up at the moment (check Merchant and Britton). They'll be far more informative than anything you'll read in the paper.

    Incidentally, we can't submit this to Nature because back in 1998 we did a pilot study, the lid of which was blown off from an unexpected source in a fit of excitement! So it's far too late for that - croc's out of the bag, etc...

    Adam Britton

  22. Re:This research... by IsoRashi · · Score: 2, Informative

    Some mods prefer to mod +1 Informative or +1 Insightful rather than +1 Funny. A funny moderation doesn't have any karma attached to it, so it's a way of working around the system to reward someone. I, myself, do it occasionally. Just an FYI.

    --
    This is not the greatest sig in the world, no. This is just a tribute.
  23. Re:Yet Another Misleading Slashdot Summary by bcwengerter · · Score: 4, Informative

    I apologize if I'm being redundant, but as of the time I'm writing this, there are 442 comments when browsing at -1, so I can't guarantee that I haven't missed something.

    In any event, I thought it might be helpful to post a link on PubMed to the abstract of the journal article to which the author of the Reuters article seems to be referring. At least, it's coming from the same lab and institution with which Dr. Britton (on his site) mentions having a collaboration. Any other references would be greatly appreciated.

    Here's the full text for those who are interested:

    1: Antiviral Res. 2005 Apr;66(1):35-8.

    Antiviral activity of serum from the American alligator (Alligator mississippiensis).

    Merchant ME, Pallansch M, Paulman RL, Wells JB, Nalca A, Ptak R.

    Department of Chemistry, McNeese State University, Box 90455, Lake Charles, LA 70609, USA. mmerchan@mcneese.edu

    Serum from wild alligators was collected and tested for antibiotic activity against three enveloped viruses using cell-based assays. Alligator serum demonstrated antiviral activities against human immunodeficiency virus type 1 (HIV-1; IC50=0.9%), West Nile virus (WNV; IC50=4.3%), and Herpes simplex virus type 1 (HSV-1; IC50=3.4%). The inhibitory concentration (IC50) is defined as the concentration of serum that inhibits 50% of viral activity. The antiviral effects of the alligator serum were difficult to evaluate at high concentrations due to the inherent toxicity to the mammalian cells used to assay viral activities. The TC50 (serum concentration that reduces cell viability to 50%) values for the serum in the HIV-1, WNV, and HSV-1 assays were 32.8, 36.3 and 39.1%, respectively. Heat-treated serum (56 degrees C, 30 min) displayed IC50 values of >50, 9.8 and 14.9% for HIV-1, WNV and HSV-1 viruses, respectively. In addition, the TC50 values using heat-treated serum were substantially elevated for all three assays, relative to untreated serum (47.3 to >50%). Alligator serum complement activity has been shown to be heat labile under these conditions. HIV-1 antiviral action was heat-sensitive, and thus possibly due to the action of serum complement, while the anti-WNV and anti-HSV-1 activities were not heat labile and thus probably not complement mediated.

    PMID: 15781130 [PubMed - indexed for MEDLINE]

  24. Re:Academic stranglehold tightens by badmammajamma · · Score: 3, Informative

    Private institutions don't do research simply for "the greater good". They do it to make money. Consequently, there's a conflict of interest. For example, if a drug company has the choice of coming up with a cure for AIDS or treatment for AIDS, you can bet your ass they will treat it and not cure it because there's no money in curing anything. An academic insitution doesn't have to worry about the profits of its research (or at least we'd like to think so).

    Perhaps that view is nieve but that's pretty much the way of things.

    --
    Any man who afflicts the human race with ideas must be prepared to see them misunderstood. -- H. L. Mencken
  25. Re:so I guess by EternityInterface · · Score: 1, Informative
    The interview mentions that? (Didn't know slashdot broke WBM)


    What about teenagers with AIDS?

    780 in the United States in the last ten years, so divided by year that's 78 per year in a country with 30 million teenagers. A third are hemophiliacs, another third are gay prostitutes, and another third are IV-drug users who started at 10 and 11. Those are your 780 American teenagers with AIDS. That's not a lot. The only significant number in people under 20 are the infants. One-or twoyear-old, possibly three-year-old babies born with AIDS in Europe and in America. A full 80 percent of them were born to mothers who were injecting drugs during pregnancy. These kids are intrauterine junkies. They have been on drugs since before they were born.

    What about the other 20 percent?

    Another 5 or 10 percent are congenital conditions like hemophilia. Some are simply infant mortality under a new name, "ghetto kids." Infant mortality is higher in this country than in all comparable industrialized nations. We have the suburbs, where you get every health care you want, and then we have places like Harlem, Richmond, Oakland, deep impoverished conditions, that you don't find in Europe where you have socialized medicine. Starvation, malnutrition, all these kinds of things. Teenage mothers who run away from the kids, or are working on the streets while the kids are alone at home. Those are the American AIDS babies.

    Is it really true that the death rate among hemophiliacs with HIV is identical to those without HIV?

    As far as we can tell from the few studies available, it's the same. In fact, the irony is, it is probably even lower. And I tell you how I arrived at that. There are 20,000 American hemophiliacs, 75 percent of them are HIV-positive. 75 percent-or 15,000-have HIV, for nearly ten years now, because as of 1984-85 they started AIDS testing, so they eliminated blood with HIV. Now, in the last 10 to 15 years, the median age of hemophiliacs has doubled. They are now twice as old as they were 10 to 15 years ago. The fact is, during that same 10 to 15 years, the Factor-VIII treatment has been developed and perfected and everybody gets it. That's the clotting factor that's missing in hemophiliacs, extracted out of blood donations and because they extract it, you extract viruses, too; that contaminated FactorVIII. But they are irrelevant, mostly harmless things, because a blood donor is typically not a terribly sick person-you wouldn't collect blood from somebody who's dying from a disease. So these are usually your ubiquitous little microbes that don't harm you. As a result, they picked up HIV. So the treatment that also brought them HIV has doubled their life.

    HIV didn't hurt them?

    No. In fact, it disproved the virus hypothesis in the largest human experiment ever done. 15,000 people infected with HIV. And now they live twice as long as hemophiliacs ever lived before in history. Better, longer.

    It's really an overwhelming point. It's not a minor experiment. We have a huge population: 15,000 people with HIV. Sure, it's true, some of them get what they call AIDS now. But they get less of it than they did before, and they get it because of transfusions. Because even now, they constantly get these transfusions. They need FactorVIII. It's not chemically clean, and that is immunosuppressive.
    --
    the sun is god
  26. Re:Money & AIDs by sampson7 · · Score: 2, Informative

    I think you have a fundamental misconception about how eminent domain works. The mega-corporation that discovers the cure for cancer is going to do an analysis and determine that in the first year, they are going to make $x, in year two, they are going to make $y, and so on until the patent expires.

    The government would look at the total value of the patent, adjust it for the time value of the money, and pay out a whopping big check.

    The whole concept of seizing something by eminent domain is that the company recieve FAIR compensation. This is in no way "government seizure" that is going to deprive the company of its money.

    Suppose your company had a brilliant invention. They think that they can make a total of $100 billion in the first 14 years of production. Would you object if the company were instead given a check up front for $100 billion minus the time value of the money? Hell no!

    I am not proposing to "disincent" private industry in any way. I am talking about taking a bold step that would pay the company its money, while at the same time ensuring that the world would have an adequate supply of the drug.

  27. Re:This research... by StikyPad · · Score: 2, Informative

    Ironically someone decided to mod you up without helping your karma by modding you funny...