Breakthrough on body's anthrax immune response discovered

Researchers at the University of Texas Medical Branch at Galveston have found that  a part of the immune system known as natural killer cells attack bacteria such as anthrax during the body's immune response.
Janice Endsley, the lead author of the paper, and her colleagues profiled the NK cell response to anthrax and documented how the cells successfully detected and killed cells that had been infected.
"People become ill so suddenly from inhalational anthrax that there isn't time for a T cell response, the more traditional cellular immune response," Endsley, a UTMB assistant professor, said. "NK cells can do a lot of the same things, and they can do them immediately."
The researchers found that the NK cells were still able to detect and kill anthrax bacteria outside of human cells.
"Somehow these NK cells were able to recognize that there was something hostile there, and they actually caused the death of these bacteria," Endsley said.
In further experiments, the group compared the anthrax infection responses of normal mice and mice that were given a treatment to remove NK cells from the body. While all the mice died with equal rapidity when given a large dose of anthrax spores, the mice with NK cells intact had much lower levels of bacteria in their blood.
"This is a significant finding," Endsley said. "Growth of bacteria in the bloodstream is an important part of the disease process."
Endsley said that the next step is to apply an existing NK cell-augmentation technique to mice in an attempt to see if having more numerous and active NK cells can protect them from anthrax. Even if the cells don't provide enough protection by themselves, they might be able to give a crucial boost in combination with a treatment of antibiotics.
"We may not be able to completely control something just by modulating the immune response," Endsley said. "But if we can complement antibiotic effects and improve the efficiency of antibiotics, that would be of value as well."
NK cells are normally associated with eliminating tumor cells and cells that have been infected by viruses.