Neutrophils: Discrete bacteria killers

Cambridge, Mass. -- U.S. biologists have discovered white blood cells known as neutrophils can distinguish among the bacteria or fungi they target for destruction.

Since neutrophils guard against bacteria and fungi infection, the Massachusetts Institute of Technology scientists said their discovery might lead to better drugs to fight pathogens.

The discovery was made by postdoctoral researcher Ifat Rubin-Bejerano and colleagues, who determined neutrophils recognize and respond to a specific form of sugar called beta-1,6-glucan on the surface of fungi. That sugar has a slightly different chemical conformation than a sugar called beta-1,3-glucan.

Because the scarce form of the sugar elicits a much stronger reaction from neutrophils than the abundant one, it appears the immune cells can distinguish between two nearly identical chemicals, the researchers said.

"These results show that engulfment and killing by neutrophils varies, depending on cell wall properties of the microbe," said Rubin-Bejerano. "We showed that neutrophils respond in a completely different way to slight changes in sugar composition. If we are able to use this unique sugar to excite the immune system, it may help the human body fight infection."

The research is reported in the journal Cell Host & Microbe.

Copyright 2007 by United Press International.