Transgenic Tobacco Produces Cheap, Effective Anthrax Vaccine
Enough anthrax vaccine to inoculate everyone in the United States could be grown with only one acre of tobacco plants, a University of Central Florida molecular biologist has found.
In his lab at the University of Central Florida Professor Henry Daniell and his team have found a safe and effective method of producing large quantities of vaccine for anthrax, one of the top bioterrorism threats facing the United States. The results of the NIH-funded study are featured in the December issue of the “Infection & Immunity Journal.”
“Anthrax vaccine is very much in need, primarily because of bioterrorism concerns,” Daniell said. “But in the United States, only one company has the capacity to produce the vaccine, and it is made in very small quantities by fermentation. We can provide enough doses of a safe and effective vaccine for all Americans from just one acre of tobacco plants.”
The scientists found that one acre of tobacco plants can produce 360 million doses in a year.
Daniell and his colleagues injected the vaccine gene into the chloroplast genome of tobacco cells, partly because those plants grow much faster than carrots, tomatoes and coffee.
They grew the cells for several weeks in Daniell’s laboratory. Tests showed the vaccine taken from the plants was just as potent as the one produced through fermentation but lacks the bacterial toxin that can cause harmful side effects.
Then the researchers injected the tobacco-grown vaccine into mice to immunize them against anthrax. They sent the mice to labs at the National Institutes of Health (NIH), where the animals survived doses of anthrax several times stronger than the amounts to which humans have been exposed.
The team includes Vijay Koya, a graduate student in Daniell’s lab, and Mahtab Moayeri and Stephen Leppla of the Microbial Pathogenesis Section of the National Institute of Allergy and Infectious Diseases at NIH.
Current production of the anthrax vaccine involves an expensive fermentation process that can cause harmful side effects such as inflammation, flu-like symptoms and rashes. This has prompted some people to refuse to be vaccinated.
The next step for the new tobacco-grown anthrax vaccine would involve a company working with NIH to conduct clinical trials. Human subjects would be injected only with the vaccine and not with anthrax itself, and scientists would then check the subjects’ immunity levels.
The vaccine later could be mass produced and stockpiled for emergencies.
Daniell conducted his study with part of a $1 million NIH grant and a $2 million U.S. Department of Agriculture grant that covers research related to genetic engineering in plants as a way to produce therapies for several diseases. His sponsors recognize that this work holds promise for dealing with other diseases such as diabetes and hepatitis, and improving vaccines for plague, cholera and other bioterrorism agents.
Daniell is developing a new technology that would enable vaccines to be administered orally and allow effective and less expensive treatments to be more accessible worldwide. He believes fruits and vegetables such as carrots and tomatoes are the keys to figuring out a way for people to take anthrax vaccines orally in capsules of dried plant cells that contain correct doses of the protective antigen.
If that research is successful, the need for doctors to administer the shots and the need to ship vaccines in refrigerated trucks would be eliminated. Doctors and refrigeration can be especially difficult in poorer nations.
The military now administers the vaccine with three shots in the first four weeks, three more in the next 17 months and then annual booster shots, according to the Pentagon.
Daniell, who is the first UCF Trustee Chair in Life Sciences, began teaching at UCF in 1998. He has formed a biotechnology company called Chlorogen to apply his work in chloroplast genetic engineering. In 2004, he won UCF’s Pegasus Professor Award, the top honor given to a faculty member who excels in teaching, research and service. Last year, he also became only the 14th American in the last 222 years to be elected to the Italian National Academy of Sciences
Provided by the Environmental News Service.
