Peptide prophylactic for a plague
August 23, 2005 1:57 PM   Subscribe

Building a better bug Scientists at a top US vaccine research lab have announced the creation of a new form of Eschericia coli, the endemic and (usually) harmless bacteria, that colonises the mucal membranes of mice and secretes a custom-built peptide. The goal? A novel method of blocking the sexual transmission of HIV in humans.
posted by docgonzo (27 comments total)
 
this is good.
posted by rxrfrx at 2:04 PM on August 23, 2005


Maybe I've watched too much science fiction, but all I can think of is scenarios in which this all goes horribly wrong.
posted by aubilenon at 2:11 PM on August 23, 2005


If you're wondering why they chose E Coli, it's because it's a 'model' bacteria, one that has been used extensively (like mice and drosphila) in genetic research. Much is known about it in comparison to other bacteria.
posted by delmoi at 2:12 PM on August 23, 2005


The researchers believe this microbial microbicide should be safe in humans because it is based on a commensal strain of bacteria (Nissle 1917) that has already been used as an over-the-counter probiotic "with an excellent biosafety record." Administration of these bacteria to mice had no inflammatory effects in the GI tract or vagina.

You can walk into any drug store and get GMO E. Coli? Wow.
posted by delmoi at 2:15 PM on August 23, 2005


I'm not sure Nissle 1917 is GMO. This new version is, to be sure, but the over-the-counter might be unmodified.
posted by docgonzo at 2:22 PM on August 23, 2005


but all I can think of is scenarios in which this all goes horribly wrong.

Such as?

Science fiction is not science.
posted by docgonzo at 2:24 PM on August 23, 2005


But if they do that, how will God punish people for having sex?
posted by mondo dentro at 2:27 PM on August 23, 2005


FYI - they've been releasing genetically engineered bacteria into nature (eg: by spraying them on crops, using them to clean up pollution in the soil) for over 2 decades now. This is by far NOT the first example of GMO microbe release. If you want PDFs, I can provide them (it's harder to find HTML sites).
posted by Moral Animal at 2:39 PM on August 23, 2005


This will exceed expectations.

So will the next project.

And the next.

And then the one after that will go horribly wrong, because everyone at Germtech starts slacking off after the budget cuts.
posted by CynicalKnight at 2:43 PM on August 23, 2005


Now I don't feel so silly about using ptomaine poisoning to cure my case of the crabs.
posted by maxsparber at 2:55 PM on August 23, 2005


Well, this looks promising. Much better than the crocodile immune system bit the other day.

It seems to me though that this would only work to help prevent new infections, not cure existing infections. Even if that is true it would be a hell of an accomplishment. I wonder if the same trick would work with Lactobacillus Acidopholus? That's a very vagina-friendly bacteria and boosting levels of it would help ward off yeast infections as well as helping prevent HIV transmission.

This new work is certainly not without its potential dangers, but an interesting new step forward regardless. I hope it bears fruit soon.
posted by afflatus at 3:21 PM on August 23, 2005


This is kinda like replacement therapy for cavity prevention. Only better, if it works...

/on preview, Metafilter: Vagina-friendly bacteria.
posted by greatgefilte at 3:23 PM on August 23, 2005


...what could possibly go wrong?

Bacteria froze the Earth, researchers say:

The Caltech team argues that 2.3 billion years ago, cyanobacteria, or blue-green algae, gained the ability to break down water, which in turn released a flood of oxygen into the atmosphere.

That oxygen reacted with the atmospheric methane, which insulated the Earth at the time, and broke it down. While the oxygen-methane reaction created the greenhouse gas carbon dioxide, the protective nature of the barrier cracked.

Temperatures plunged to minus 50 degrees Celsius, and ice at the equator grew to 1 mile thick.


Until they catch a cold, I, for one, welcome our new microscopic underlords...
posted by cenoxo at 3:23 PM on August 23, 2005


I wonder if the same trick would work with Lactobacillus acidophilus? That's a very vagina-friendly bacteria and boosting levels of it would help ward off yeast infections as well as helping prevent HIV transmission.

Same basic idea, but this new version on E.coli works by secreting antiviral peptides, and acidophilus works by producing lactic acid (and other bi-products, such as hydrogen peroxide) as it digests whatever it is that it eats, which makes the environment hostile for undesired organisms. Acidophilus won't scare the HIV, not even close.

Anyway, I hope this really is going somewhere.
posted by Specklet at 3:36 PM on August 23, 2005


"A novel method of blocking the sexual transmission of HIV in humans."

Yeah, 'cause condoms are for sailors, baby.

Damn scientists. Wasn't fire enough?
posted by Smedleyman at 4:13 PM on August 23, 2005


This is the kind of GMO work I can stand behind, I have to say. I'm not wild about fiddling with plants or animals that we eat, but for some reason I'm not quite as grossed out by the thought of GMO bacteria. Not sure why...
posted by Deathalicious at 4:39 PM on August 23, 2005


Yeah, 'cause condoms are for sailors, baby.

It has long been recognised that the heterosexual spread of the virus, especially in Africa, has been aided by the refusal of men to use condoms and the inability of women, especially commercial sex workers, to insist on their use. Thus an effective biocide -- especially one that a woman could apply before sex and would be imperceptible to her partner -- tops the priority list of many public health officials.
posted by docgonzo at 4:42 PM on August 23, 2005


Y'know, just because this could be released into the environment, doesn't mean that it has to in order to be effective. For example, they could make an inhaler for it. That would be a lot less risky then large-scale environmental deployment.
posted by afroblanca at 4:46 PM on August 23, 2005


This is the kind of GMO work I can stand behind, I have to say. I'm not wild about fiddling with plants or animals that we eat, but for some reason I'm not quite as grossed out by the thought of GMO bacteria. Not sure why...

Because GreenPeace told you so.

That's the scary thing - the GMOs we should be more careful with, no one cares about (how do you control microbes??), but GreenPeace and others like them tell you that - OMG! You're eating FRANKENFOOD! - and everyone shits their pants.

Plants and animals seem more "natural" and something we can handle and relate to, whereas microbes are less real. But the fear most people have isn't based on rational thought, but rather fabricated ideas and facts. There are real fears regarding this science, but most of us don't know about them because of the unrelenting propaganda of the anti-GMO groups.

/soapbox
posted by Moral Animal at 4:54 PM on August 23, 2005


afroblanca: I don't imagine they would release it indiscriminately but as some sort of topical cream of something.
posted by docgonzo at 5:03 PM on August 23, 2005


What I'm worried about is, these are bacteria - they're subject to pretty high rates of mutation and mutations that result in happier bacteria = those bacteria are going to take over.

So, how much does producing a viricide require from the bacteria or are they happy chruning this stuff out? (Yes, there are systems to ensure that whatever it is that you make the bacteria produce is maintained but ... the world's a big place)

Also,with L. acidophilus - why couldn't they produce the same viricide as E. coli? Taking care of yeast and HIV with only one microorganism - hooray!

And didn't Sterling (or Stephenson) envision this a long time ago - using modified commensal microorganisms to outcompete microbes that produce undesireable body odour? Now if they can only come up with one that outcompetes with Propionibacterium acnes without growing too fast. Heck, maybe just break down sebum so it can't be eaten or something. Please?
posted by PurplePorpoise at 5:15 PM on August 23, 2005


afroblanca: ...they could make an inhaler for it. That would be a lot less risky then large-scale environmental deployment.

True, but what happens when the user exhales? (We inhale and exhale about a half liter of air wih every breath.) All of those modified bacteria aren't going to grab onto something on the way out.
posted by cenoxo at 5:23 PM on August 23, 2005


What I'm worried about is, these are bacteria - they're subject to pretty high rates of mutation and mutations that result in happier bacteria = those bacteria are going to take over.

No matter their inherant rates of mutation and substitution -- which shouldn't, afaik, be any higher in the modified MOs than the originals -- they are still bound by the same general ecological principles, especially: too many bacteria + not enough food = decline in populations
posted by docgonzo at 5:56 PM on August 23, 2005


I think eucaryotes are more suseptable to mutation then bacteria, with all the crazy recombination going on. But I could be wrong. It's viruses that mutate all the time.
posted by delmoi at 6:27 PM on August 23, 2005


delmoi - bacteria have much more recombination - and gene exchange (think bacterial mating) - than eukaryotes. They don't have the complex gene repair mechanisms we do and environmental mutagens affect them more than they do us. Conjugation (bacterial mating) is one of the things that worries me about GE bacteria - they can exchange their genes with related bacteria and have the gene propagate through many strains of bacteria. Just one of the many ways scientists can lose control of their creations.

And docgonzo is right - the mutation rate wouldn't change, but if the GE bacteria are "more fit" in whatever environment they are put in, they will dominate, for better or for worse.
posted by Moral Animal at 7:15 PM on August 23, 2005


I doubt they could be more fit -- after all, some of their cellular machinery is being co-opted to produce a protein that doesn't benefit them in any way. I'd guess that you'd have to reapply them every so often.
posted by breath at 7:58 PM on August 23, 2005


Very interesting, but also very preliminary. What the articles do not say is whether the levels of the fusion inhibitor is known to be sufficient to inhibt fusion. I understand that you can't test HIV fusion in mice, but just because they acheived "micromolar" levels of the peptide does not mean that fusion would be significantly inhibited. It seems a strange bit to leave out.
posted by OmieWise at 5:56 AM on August 24, 2005


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