ACS Washington 2009: Antibodies for weapons
In the spirit of this year's theme at ACS, "Chemistry and Global Security", I decided to stop by the symposium "Sensing and Destroying Chemical Warfare Agents and Pesticides", where Kim Janda from Scripps was giving a talk about simple solutions to detecting weapons.
It's a pretty cool and important topic, and Janda's a big name, so I was pretty excited — but my excitement dropped when Janda began his talk with a disclaimer:
"The coolest stuff I've got I'm not allowed to talk about, and the really interesting stuff I'm doing with therapeutics doesn't fit with this symposium."
So it goes at big conferences. Janda ended up giving a review some of his work in this area, which was fine for me because I didn't know much about it.
Janda's developing antibodies to detect some of the nastier chemicals that could be turned into weapons: sarin, soman and vx. It turns out these all have the same "chemical signature", in that they all naturally degrade to methylphosphonic acid (MPA). The idea is this might translate into lab-based or even portable assays for detecting minuscule quantities of toxin.
Apparently MPA isn't the easiest target for antibody development, so Janda did some tweaking — modifying the protein to make it better at inducing an immune response, and eventually ditching the "classic" method of producing antibodies (using hybridoma cells) in favor of screening massive libraries in vitro. The library method uses viruses, which all display a different variant of antibody or other peptide on their surface.
Using this technique, Janda found antibodies not only to MPA, but also to anthrax, abrin and botulinum toxin. Using the MPA antibodies he could detect 1 pg/ml, while the "gold standard" (feeding it to a mouse and seeing how much time passes before it dies) can only detect if it's more than 10-20 ng/ml.
To screen for antibodies to botulinum toxin, he mentioned that he "used SPR [a type of biosensor] because a certain group that gives us money wants us to use it".
