Scientists Bring Salmonella’s Immune Trickery to Light

Salmonella bacteria

Researchers have identified a molecular trick that may explain part of the fierceness of Salmonella, the rod-shaped bacterium that causes misery for millions of people. In research recently published in PloS One, a Medical Center team led by Jun Sun, Ph.D., identified a protein that allows the bacteria to maintain a low profile in the body, giving the bacteria crucial time to quietly gain a foothold in an organism before the immune system is roused to fight the invader. It’s an important new finding about an ancient nemesis, in an area of strategic importance for the Medical Center – learning more about how immune system repels dangerous invaders.

Sun’s team found that a virulence protein known as AvrA dampens the body’s inflammatory response. That helps the bacteria avoid the wrath of the immune system and gives the infection crucial time to grow and develop before it needs to expend energy to fight off immune cells like neutrophils, which would attack the intruder more quickly if the bacteria attacked the body in a more clear-cut fashion.

“AvrA allows Salmonella to make peace with you, buying the bacteria a little time to survive in the body,” said Sun, assistant professor of Gastroenterology and Hepatology. “That’s bad news for the body, because then the bacteria spreads. AvrA allows the bacteria to do harm in the body without the body realizing it. Bacteria have been evolving for millions of years. That gives them some tricks that perhaps we don’t understand yet.”

Click here to read more about Dr. Sun’s research project.