Look at them Choppers!

August 16, 2005 10:12 AM

Crocodile Immune System Kills HIV
Because crocodiles fight amonst themselves and get seriously wounded from time to time they developed incredibly strong immune systems and natural antibiotics. So strong that they, well, let's hear from one of the scientists.... "The crocodile has an immune system which attaches to bacteria and tears it apart and it explodes. It's like putting a gun to the head of the bacteria and pulling the trigger," said Australian scientist Adam Britton.
Sounds like good news to me.
posted by fenriq (45 comments total)

And bad news for crocodiles.
posted by agregoli at 10:18 AM on August 16, 2005

So is this how humans eventually evolve into the lizard people time travelers.

Man, this tin foil itches.
posted by Pollomacho at 10:18 AM on August 16, 2005

"The crocodile has an immune system which attaches to bacteria and tears it apart and it explodes. It's like putting a gun to the head of the bacteria and pulling the trigger,"

Sounds like somebody had better call the hyperbolyyyyyaaambulance
posted by delmoi at 10:19 AM on August 16, 2005

Problems with this article: antibiotics don't kill viruses, viruses aren't considered life (organisms), and your body's immune system would forcibly reject any croc antibodies injected into you, assuming you had collected enough natural supply to reduce HIV counts to begin with...

Well, at least the scientist didn't throw "crikey" into the description.
posted by Rothko at 10:20 AM on August 16, 2005

Also, I doubt that the human imune system would have many problems dispatching a virus that had evolved to infect a totaly diffrent Animal.
posted by delmoi at 10:21 AM on August 16, 2005

No wonder the lizards in Gilliam's adaptation of Fear and Loathing were so promiscuous!
posted by cavalier at 10:23 AM on August 16, 2005

I wonder how often crocodiles suffer from autoimmune disease?
posted by Grimgrin at 10:26 AM on August 16, 2005

Rothko, from the bottom of the article,
However, the crocodile's immune system may be too powerful for humans and may need to be synthesized for human consumption.

Damn, I wish I'd thrown a crikey into the post now.
posted by fenriq at 10:28 AM on August 16, 2005

Now..let..me..just..get...my...thumb..in..there...
(/southpark)

Between aligator immune system injections, shark cartalidge tablets, and eating monkey brains, I feel like a whole new person!
posted by Balisong at 10:30 AM on August 16, 2005

Um, kinda cool, but you know, the human immune system also kills HIV, and quite effectively. That's why it takes 10 years (on average) to progress from HIV infection to AIDS (as defined by a CD4 count of less than 200). If HIV did not attack the immune system itself, eventually weakening it, the virus would be controlled quite well by the human system.
posted by OmieWise at 10:32 AM on August 16, 2005

Problems with this article...

Well the reporter obviously has very little idea what he's talking about, but that doesn't mean that the scientists don't as well.

your body's immune system would forcibly reject any croc antibodies injected into you,

There is a long history of using neutralizing antibodies from other organisms therapeutically. Antivenom produced in horses for human use is the first thing I can think of.

Unfortunately, previous studies have shown that using neutralizing antibody mechanisms alone will not neutralize an HIV infection.
posted by grouse at 10:33 AM on August 16, 2005

This is cool.

I'm also looking forward to crocodillin to treat antibiotic-resistant bugs, and the synthetic human blood made from crocodile hemoglobin.
posted by selfmedicating at 10:34 AM on August 16, 2005

Grimgrin writes "I wonder how often crocodiles suffer from autoimmune disease?"

This is a really good question, unfortunately, there are several human autoimmune diseases that have common names that derive from crocodile (crocodile tears (associated with Bell's Palsy) and crocodile skin), so googling crocodile & autoimmune returns no hits about the actual animals.
posted by OmieWise at 10:35 AM on August 16, 2005

attaches to bacteria and tears it apart and it explodes

Crikey, that's a reeeeally agressive macrophage!
posted by CynicalKnight at 10:36 AM on August 16, 2005

Now I feel so much better about eating all those crocodiles. You can't just stop at one!
posted by maxsparber at 10:44 AM on August 16, 2005

Between alligator immune system injections, shark cartalidge tablets, and eating monkey brains, I feel like a whole new person!

I can't tell if it's the rhino horn or the tiger penis soup, but my wife and I look like we belong in an Enzyte commercial!
posted by Pollomacho at 11:03 AM on August 16, 2005

I hope this doesn't turn into a repeat of Ol' Doc Connors.
posted by The Cardinal at 11:04 AM on August 16, 2005

This is actually kinda old news.

Well, REM wrote a song alluding to it anyway, back in '96'.

'Course, Michael Stipe may have been a bit closer to it than mainstream media at the time.
posted by elendil71 at 11:17 AM on August 16, 2005

Man, those Australian scientists love their descriptions.

I can only assume the mixed scientific language (antibiotics being linked with viruses as well as bacteria, etc) is due to the reporter writing the article, not the scientists themselves.

Even though the crocodile's immune system is much stronger than the human one and we can't just port over what we need, I still would have hope that this information and research could be used to speed along a vaccine of some types (although with a retrovirus like HIV, that's a difficult prospect). Either that or the drug from Japan that was mentioned on here about a month ago.

I'll leave without a "Crikey" joke, although it seems to be the price of admission to this thread.
posted by Drylnn at 11:18 AM on August 16, 2005

Now I feel so much better about eating all those crocodiles. You can't just stop at one!

Yeah, and I feel so much safer about screwing them, now that I know I won't get HIV!
posted by Kickstart70 at 11:29 AM on August 16, 2005

Bring on the Visitors
posted by LinemanBear at 11:30 AM on August 16, 2005

By the way, fenriq, props for the Romancing the Stone post title.
posted by OmieWise at 11:50 AM on August 16, 2005

The crocodile has an immune system which attaches to bacteria and tears it apart and it explodes

1. What does this have to do with HIV?

2. People have this functionality too, it's called the Membrane Attack Complex.
posted by rxrfrx at 12:16 PM on August 16, 2005

(And by cranky comment #1, I mean why did they bring up bacteria)
posted by rxrfrx at 12:17 PM on August 16, 2005

I feel like copy & pasting the whole friggin' article here.

rxrfrx:
Initial studies of the crocodile immune system in 1998 found that several proteins (antibodies) in the reptile's blood killed bacteria that were resistant to penicillin, such as Staphylococcus aureus or golden staph, Australian scientist Adam Britton told Reuters on Tuesday. It was also a more powerful killer of the HIV virus than the human immune system.

"If you take a test tube of HIV and add crocodile serum it will have a greater effect than human serum. It can kill a much greater number of HIV viral organisms," Britton said from Darwin's Crocodylus Park, a tourism park and research center.

Obviously there's hope in these results. The real crux of it is in whether it prevents HIV attacking the immune system, as earlier posters have said.
posted by dash_slot- at 12:28 PM on August 16, 2005

Does anyone know of links to a more scientific presentation of this information?

The description of the immune system tearing apart bacteria and making it explode just sounds like a dramatic description of the human complement cascade. (rxrfrx astutely referenced the final step of the cascade, attachment of the Membrane Attack Complex).
posted by corranhorn at 12:41 PM on August 16, 2005

I can't find it on the net now, but I read a year or two ago that AIDS is rampant in lions, that basically they're swimming in it. But their immune system is so overpowered that they can handle it (evidently they adapted to AIDS some time ago).

I would have thought that hippos would have even better immune systems than crocs, insofar as they wallow in their own filth. (Nothing quite like it for cooling the blood!)
posted by Aknaton at 12:56 PM on August 16, 2005

OmieWise, thanks, I was wondering if anyone would notice or get it.
posted by fenriq at 1:06 PM on August 16, 2005

I would have thought that hippos would have even better immune systems than crocs, insofar as they wallow in their own filth. (Nothing quite like it for cooling the blood!)

I really need to try that sometime.
posted by grouse at 1:27 PM on August 16, 2005

Now, it's been a while since I took immunology, and I'm being lazy and not looking things up, but I don't think we're even talking about antibodies here. Fish, reptiles, and amphibians, last I knew, use chemical antibiotics as their primary defense systems rather than the "flag-and-call-in-a-response" approach of mammalian antibodies. The antibiotics should be of use against bacteria, and there very well could be antiviral molecules as well, but they won't be the same chemicals and won't have universal applicability.

I wonder what the actual original studies were? Merchant has done works with croc blood for its anti-amebal (neither bacteria nor viruses) qualities, and he and Britton have studied anti-bacterials (always called antibiotics in those sources), but no anti-virals that I can find (although there appears to be a Mark Merchant that works with computer viruses). This looks like a reporter who, typically, has no clue of the differences between antibiotic and antibody or bacteria and virus, and is extrapolating based on ignorance.
posted by DarbyMac at 1:55 PM on August 16, 2005

Waitasecond. Some Crocodiles are gay? Huh.
posted by monkeyboy_socal at 2:27 PM on August 16, 2005

I agree with those who say this article makes no sense. If the crocodile is producing antibodies to HIV then he is being challenged with HIV or a part of it. Those antibodies are supposed to be more powerful than human HIV antibodies? The problem with human infection doesn't lie in weak human antibodies in the first place. If it's not antibodies what are they comparing it to for human antiviral serum response? Are crocodiles supposed to be making a natural antiviral compound that works non-specifically (unlike antibodies which have a specificity)? That's hard to imagine given the extreme diversity of viruses out there. It just happens to act on HIV -- which is an extremely diverse virus in itself.
It's not just the reporter who seems unclear. "If you take a test tube of HIV and add crocodile serum it will have a greater effect than human serum. It can kill a much greater number of HIV viral organisms." This statement is wincingly bad. Human serum without antibodies doesn't kill HIV. Human serum with antibodies doesn't kill HIV either, it would present it to the leukocytes for the killing which aren't present in serum. Of course HIV isn't considered alive.
posted by dances_with_sneetches at 3:07 PM on August 16, 2005

The most dubious part of this is that it's science by Reuters. Journalists are far from being the most qualified group of people for evaluating scientific work. Has any other doctor/scientist sort of person looked at their results, or was it just Michael Perry? It's not that hard for scientists to get press in the nonscience media if they want it, especially regarding big-news issues like HIV.

Adam Britton's publication list also doesn't indicate any background in immunology, virology, microbiology or medicine.
posted by shoos at 7:08 PM on August 16, 2005

Now let's kill all the crocodiles and get all the cure at once!

Does that remind anyone of a certain fable?
posted by clevershark at 7:39 PM on August 16, 2005

Here also is Mark Merchant's page at McNeese State University.

It's strange, I tried looking up his three most recent listed publications on PubMed, and none of them was there. And the only references to them I could find using Google were from his own web page.
posted by shoos at 7:44 PM on August 16, 2005

Kinda OT, but I just love it when scientists explain things in everyday English. The quote from the OP, reminded me of an article on building an exoskeleton for soldiers I read a few years ago. One of the developers was talking about the efficiency and power of human muscle: "Muscle is so damn good at this stuff. If you took all of the muscles off of a healthy adult male and put them in full contraction, they would lift 20 tons. And they run on carrots."
posted by snwod at 7:47 PM on August 16, 2005

Reuters publishes a lot of good science articles. This isn't one of them.
posted by dances_with_sneetches at 7:58 PM on August 16, 2005

shoos, I think his page is a bit out of date, according to this PubMed search.
posted by gsb at 4:27 AM on August 17, 2005

Here's a chap who applied his croc externally. Unfortunately, it was still alive.
posted by emf at 4:33 AM on August 17, 2005

I can't find it on the net now, but I read a year or two ago that AIDS is rampant in lions, that basically they're swimming in it. But their immune system is so overpowered that they can handle it (evidently they adapted to AIDS some time ago).

Just a couple of clarifications, since the terminology is fairly important here:

1) If the lion immune systems are killing the virus, then the lions do not have AIDS. AIDS comes after the body's defenses have been overwhelmed.

2) In any case, no animal need worry about HIV, which is a Human virus, hence the H. There may be a FIV, for feline, just as there is an SIV for chimpanzees (simian).
posted by OmieWise at 7:33 AM on August 17, 2005

It was also a more powerful killer of the HIV virus than the human immune system.


I shall go to the ATM machine and get money to contribute to this research! I hope I can remember my PIN number. Can I get the study information in PDF format?
posted by norm at 9:33 AM on August 17, 2005

gsb, true, but it should raise a little concern that the only citations or mentions of his work are from himself and Reuters. Look him up at Science Citation Index.
posted by shoos at 2:53 PM on August 17, 2005

This is not an endorsement.

There's a long history of articles that receive very few or no citations, initially, because the research was not 'trendy/useful/applicable/good for grant writing/nice for high-impact journals' instantly. In some cases, science takes time to be heavily cited... etc. As a useful metric, citations are good, but one needs more than a single measure for these things.
posted by gsb at 4:05 PM on August 17, 2005

There's also a much more vast history of articles that received little or no attention because they didn't merit it.
posted by shoos at 5:58 PM on August 17, 2005

shoos, of course there's a vast history of shite, and I understood that from your earlier comment. And I guess this comment is further equivocation to your equivocation, ad nauseum.
posted by gsb at 2:37 AM on August 18, 2005