Virulence Factors of Ebola, Anthrax Elucidated
Modified Ebola virus safer, can be studied outside of biosafety level-4 facility
WEDNESDAY, Jan. 23 (HealthDay News) -- Anthrax bacteria require production of their own nitric oxide (NO) to be virulent, one group of researchers has found, while another research group has generated a modified Ebola virus that can be safely handled outside a biosafety level-4 facility, according to two studies published online Jan. 22 in the Proceedings of the National Academy of Sciences Early Edition.
In the first study, Konstantin Shatalin, from New York University School of Medicine in New York City, and colleagues investigated the role of endogenous NO in defending Bacillus anthracis from oxidative stress. The investigators found that the bacteria's survival in vivo was critically dependent on its own NO-synthase activity, which was necessary for virulence and survival within macrophages.
"Our results demonstrate that pathogenic bacteria use their own NO as a key defense against the immune oxidative burst, thereby establishing Bacillus anthracis NO synthase as an essential virulence factor," Shatalin and colleagues conclude.
In the second study, Peter Halfmann, from the University of Wisconsin-Madison, and colleagues generated an Ebola virus lacking an essential transcription factor. The virus grew to similar titers as wild-type virus, had indistinguishable morphology and was genetically stable. This modified virus was only able to replicate in cells stably producing the missing factor.
"We propose that this system provides a safe means to handle Ebola virus outside a biosafety level-4 facility and will stimulate critical studies on the Ebola virus life cycle as well as large-scale screening efforts for compounds with activity against this lethal virus," Halfmann and colleagues conclude.