PLANT vs. PATHOGEN: Enlisting Tobacco in the Fight Against Anthrax

Abstract

Just weeks after the September 11 terrorist attacks in New York and Washington, letters containing anthrax spores were mailed to newspapers and television stations in New York and to two U.S. senators on Capitol Hill. Although only a few letters were sent, 22 people were infected and 5 died. More importantly, the bioterror attacks fueled fears that future attacks might be more extensive. Now researchers at the University of Central Florida are helping to prepare for the possibility of anthrax attacks by developing a new technique that can quickly produce hundreds of millions of doses of a potentially safer anthrax vaccine. Since the 1960s American microbiologists have produced a vaccine for anthrax from the very microbe itself, Bacillus anthracis. The microbe’s toxin is made up of three key parts: edema factor (EF), lethal factor (LF), and protective antigen (PA). EF causes fluid to build up in the area of infection, while LF kills cells or prevents them from working. However, both of these factors require PA to create a passageway into the cells—the PA bonds to protein receptors, creating a new complex to which the other two factors attach. According to Stephen Leppla, a senior researcher at the National Institute of Allergy and Infectious Diseases (NIAID), anthrax bacteria that don’t have PA cannot cause an infection. “In essence,” he says, “they are inactivated and become much less virulent.” The current anthrax vaccine works on this very antibodies are created. PA introduced in the event of a future anthrax exposure would be inactivated by these antibodies, stopping the infection in its tracks.