New findings by a team of Montana State University microbiologists shed light on how bacteria successfully protect themselves from viruses using their clustered regularly-interspaced short palindromic repeats (CRISPRs), which is key to the recent advancements in genetic modification.
"Bacteria get viral infections just like humans do," Blake Wiedenheft, coauthor of the paper, said in a press release. "Recently we discovered that bacteria have sophisticated immune systems, called CRISPRs, and our work aims to understand how these immune systems work."
The new research gives scientists a better understanding of how CRISPRs separate virus DNA from its own genetic material, allowing it to effectively fight off the virus without damaging the host cell with its own anti-viral measures.
"Targeting the foreign DNA stored in the bacterial genome would result in an auto-immune reaction that would kill or at least make the bacteria very sick," Wiedenheft said. "The work in this paper explains how the immune system in 'Escherichia coli' differentiates between the bacteria's own genetic material and that of the virus."
In order to reach their conclusions, the team used a technique called X-ray crystallography to create a blueprint of the immune systems' surveillance system through the analysis of foreign DNA.
"These blueprints, which are conceptually similar to a builder's blueprint, explain how these biological machines work," Wiedenheft said. "We are now trying to use these blueprints to engineer this system for novel applications that Mother Nature never expected."
Understanding these processes in bacteria will help transform the use of CRISPR systems in human medicine and biotechnology, allowing scientists to better cut and repair human DNA.
"CRISPR systems have now been moved into human cells, and we can now program these systems to cut out and repair defective DNA in human cells," Wiedenheft concluded.
The findings were published in the Feb. 10 issue of Nature.
