Thursday, June 08, 2006

Transgenic chicken paradox

Maybe if I didn't spend a lot of time thinking about bird flu and chickens I wouldn't have noticed this. But I did, so I bring it to you.
Origen Therapeutics announced today that it has succeeded in developing a robust and versatile technology for genetically modifying chickens that, for the first time, puts avian transgenics on a par with transgenic mice. The company made the announcement in conjunction with the publication of an article this week by Origen scientists and a collaborator from the University of California, Davis on its transgenic technology in the journal Nature. Using the new technology, Origen can, in principle, make any genetic modification desired to the chicken genome, including the insertion of genetic elements for the production of human therapeutics and the modification of the chicken immune system to produce novel human sequence polyclonal antibodies. Moreover, the new technology opens up the possibility of producing chickens with enhanced agronomic traits, including resistance to avian flu. (Press release via rxpgnews)
The technology uses, interestingly enough, chicken embryonic stem cells. President Bush has yet to outlaw chicken stem cell research, so this is legal (so far; but you never know). The idea is to modify the chicken genome to produce drugs and biologicals.
"We believe a transgenic chicken system offers a number of advantages over either plant or other transgenic animal systems for protein production. Besides the ability to produce antibodies with enhanced cell killing properties, the time from antibody identification to production in eggs is a matter of months, the purification of proteins from eggs is relatively simple, and good manufacturing practices have long been established for vaccine production in chicken eggs. Moreover, the overall cost of facility and operations is a fraction of that associated with fermentation methods of manufacture. The ability to readily create transgenic chickens through this technology, and then to scale up production through conventional breeding further adds to the practicality of this technology for large-scale production of therapeutic proteins," [said Robert Kay, Ph.D., Origen Therapeutics president and chief executive officer].


"This work addresses a major biomedical issue -- how to produce antibody-based medicines in an easy, cost-effective way," said Matthew E. Portnoy, Ph.D., of the National Institute of General Medical Sciences, which partially funded the research.
The irony of this "breakthrough" is just too delicious. Consider. We are already terrified of one biological agent produced in chickens, H5N1 viral protein and its genetic material (in the form of a virus). We cannot rely on egg-based technology to make another badly needed biological, a vaccine against the first chicken-produced biological, so we are desperately trying to move to cell-culture techniques where the vaccine will be produced in large fermenters because it will be quicker and cheaper. Now we have the proposal to use transgenic chickens to make still other biologicals with an egg-based technology because using fermenters is too costly and not fast enough.

Go figure.