Targeting Cellular Invaders

My colleague Sam Fahmy brings us this story today, from UGA researchers harnessing bacterial immune systems to fight infection and disease:

“Scientists study bacteria and other microorganisms to understand essential life processes as well as to improve their use in the safe production of foods, biofuels and pharmaceuticals, and to fight those that cause disease,” said Michael Terns, a professor in the departments of biochemistry and molecular biology, and genetics in the UGA Franklin College of Arts and Sciences. “And now we have a new way to engineer bacteria to decrease or even eliminate the expression of the genes of our choosing.”

The bacterial immune system consists of two components. The first is an RNA (a molecule that, like DNA, contains genetic information) that acts as a homing signal to target a virus or another cellular invader. The second component is a complex of proteins that cleaves the invader’s genetic material. In a 2009 paper published in the journal Cell, Terns, co-principal investigator Becky Terns and their colleagues were the first to describe how this pathway, known as the Cmr branch of the CRISPR-Cas immune system, works.

In their latest study, the researchers further their understanding of the system and use that in-depth knowledge to essentially hijack the bacterial immune system to direct its homing system to a target of their choosing. Using customized CRISPR RNAs with a modified homing signal, the scientists were able to destroy the message for a protein that is responsible for resistance to the most commonly prescribed family of antibiotics, the beta-lactam antibiotics (that includes, for example, amoxicillin).

Modified gene expression in bacteria is the kind of research that has an extraordinarliy wide range of potential uses, impacting the production of everything from biofuels to insulin. Scientists (and science writers) shy away from using words 'breakthrough' and 'discovery', and usually for good reason.  But it's becoming increasingly difficult to deny the impacts of the work going on at this campus and many others, with the support of federal agencies investing in the future health of the nation, the NIH and ARRA in this case.