Animal-free Antibodies

I just found this unpublished post in my list.  I wrote it three years ago, but I hope it tides you over for my next post.

Structure of an IgG2 antibody

Working in biology, especially biochemistry, one invariably has to run Western blots and/or immunoprecipitation. If these pan out, you might do an ELISA (or Enzyme-Linked Immunosorbent Assay if you never wrote it out). What all these depend on are antibodies. Something that still takes injecting a rabbit (or goat, or mouse) with something acting as the antigen, bleeding the rabbit a few times, and then eventually killing it. Not a very happy method for our mammalian buddies.

And it's often not a very effective method. You have to have many different rabbits to get one somewhat decent antibody. And even if you do eventually end up with a monoclonal antibody, it still isn't that reliable, as the existence of a antibody validation site like AntibodypediA shows.

Work is being undertaken to change both the unreliability and the animal welfare impact of antibodies. An article I read recently shows that while this research is still in early stages, it is getting results. The researchers vary a protein sequence using a computer database, and then select for binding efficiency with a column. The proteins are presented on a phage, which being a biological system can add to genetic variation on its own and thus improve selection.

It also reminded me of work being done with antivenoms (or antivenins depending on which flavor of English you speak). Currently antivenoms are obtained by raising poisonous animals, be they snakes, anthropods, or whatever. A dangerous occupation, as I saw first (severely scarred) hand on a recent trip to the สถานเสาวภา Queen Saovabha Memorial Institute snake farm. The venom is diluted and injected into large animals. In Thailand they mentioned using elephants, but outside of the tropics horses are often used, and more recently, sheep. The antivenom is basically an antibody to the venom.

Besides the above-mentioned issues with antibodies in general, antivenoms also have the trouble of causing immune responses in the afflicted individuals: Both to the antivenoms and to unrelated serum proteins in the antivenom dose.

The positive aspect of antivenoms-as-antibodies is that they generally do not change over time, as selective pressure is very low. That means that once one has a good antivenom, it will work for a long time before having to be re-engineered. Once you have a good binding site, you can make a synthetic antibody containing just the ends of the short and long chains, and replace the rest if the antivenom with something that doesn't produce anaphylaxis.






AntibodypediA
The Importance of Being Tyrosine: Lessons in Molecular Recognition from Minimalist Synthetic Binding Proteins. ACS Chem. Biol., 2009, 4 (5), pp 325–334; Publication Date (Web): March 19, 2009

French Stop Testing Oysters on Mice

Yes, you read that right. I heard this first on the radio, but there are better text versions here in English and here en français.

The gist is that since oysters are filter-feeders in the big wide ocean, and not raised in a closed system of a farm, and they can pick up pathogens pretty easy. So there are naturally food-safety concerns (ignoring the heavy metals and toxins). So many governments started testing digestive fluid from the oysters by injecting it into mice and seeing if they died (the mouse bioassay, or test de la souris). Very base test. Fast forward a few decades, and most governments find faster, cheaper, more reliable, less cruel ways to test the pathogenicity of oysters. Yet up until recently, France was shelling out money (yuk-yuk) for the old muricidal method. Finally, they have switched to the better-in-almost-every-way chemical test.

Why did this happen? Seems many French oyster farmers were upset that mice oftentimes die even if the oysters were 'clean.' This would mean whole regions of coast would be banned from selling oysters, and many people went bankrupt and so forth. So the oysterfolk complained, and eventually got the change they wanted. I can find no indication that any animal-rights groups were involved (they dropped the ball)

Now I am glad that more mice are living, but upset that perhaps more oysters will die. I am more glad that another unreliable animal test has been ditched in favor of a more reliable cruelty-free test. Though I can not find out precisely which test they are using now, it is a good point to bring up when people tell you that animal testing is 'needed.'