Researchers Discover Immunity-boosting Molecule To Fight Bacterial Attack

According to a study published in the Journal of Innate Immunity, a team of researchers, including one of Indian-origin, has discovered how a protein molecule in immune cells promotes the production of nitric oxide. It is a potent arsenal that helps defend the body from bacterial attack.

The protein molecule may offer a target for reining in the inflammatory response, which must be able to fight infection without damaging tissue.

Ravi Ranjan, an Indian-American research scientist at the University of Illinois, Chicago, said, “NFATc3 is one of several related protein molecules known to play a role in regulating genes in the T and B cells of the immune system.” Rajan is also the first author on the paper.

The Indian-American scientists and his collaborators wanted to know if NFATc3 also had any function in macrophages - specialised killer cells that hunt down, engulf and destroy marauding bacteria. Macrophages play a vital role in reducing an out-of-control reaction to infection that can cause organ failure and death. It is also important in lowering the inflammation in sepsis.

When the scientists exposed macrophages to chemicals that signal a bacterial infection, they noticed that NFATc3 increasingly bound to genes that boost the production of nitric oxide synthase — the enzyme that makes nitric oxide.

"Without the ability to synthesise inducible nitric oxide synthase, a macrophage would be missing a key element of its chemical weaponry. We would expect these cells to be much less effective at killing bacteria and attenuating sepsis," said Ranjan.

"An overproduction of nitric oxide can actually contribute to lung injury, even as it helps clear bacterial infections. An NFATc3 inhibitor, given as a drug to people in septic shock, may be a way to ease the harmful effects that come with an overproduction of nitric oxide," he concluded.
(Image: Thinkstock)