Researchers Discover Biological Basis of 'Bacterial Immune System'

Athens, Ga. – Bacteria don’t have easy lives. In addition to mammalian immune systems that besiege the bugs, they have natural enemies called bacteriophages, viruses that kill half the bacteria on Earth every two days. 

Still, bacteria and another class of microorganisms called archaea (first discovered in extreme environments such as deep-sea volcanic vents) manage just fine, thank you, in part because they have a built-in defense system that helps protect them from many viruses and other invaders.

A team of scientists led by researchers at the University of Georgia has now discovered how this bacterial defense system works, and it could lead to new classes of targeted antibiotics, new tools to study gene function in microorganisms and more stable bacterial cultures used by food and biotechnology industries to make products such as yogurt and cheese.

The research was published in the journal Cell.

“Understanding how bacteria defend themselves gives us important information that can be used to weaken bacteria that are harmful and strengthen bacteria that are helpful,” said Michael Terns, a professor of biochemistry and molecular biology in UGA’s Franklin College of Arts and Sciences. “We also hope to exploit this knowledge to develop new tools to speed research on microorganisms.”
           

Other authors on the Cell paper include Rebecca Terns, a senior research scientist in biochemistry and molecular biology at UGA; Caryn Hale, a graduate student in the Terns lab at UGA; Lance Wells, an assistant professor of biochemistry and molecular biology and Georgia Cancer Coalition Scholar at UGA and his graduate student Peng Zhao; and research associate Sara Olson, assistant professor Michael Duff and associate professor Brenton Graveley of the University of Connecticut Health Center.

The system, whose mechanism of action was uncovered in the Terns lab (Michael and Rebecca Terns are a husband-wife team), involves a “dynamic duo” made up of a bacterial RNA that recognizes and physically attaches itself to a viral target molecule, and partner proteins that cut up the target, thereby “silencing” the would-be cell killer. 

Read the full story at UGA.