Researchers identify key molecular step to fighting off viruses

Apr 21, 2010

UT Southwestern Medical Center researchers have determined how a protein that normally latches onto molecules inside cells and marks them for destruction also gives life to the body's immune response against viruses.

The researchers discovered that a certain form of the "death" ubiquitin interacts with another protein, called RIG-I, but does not mark it for destruction. Instead, this form of ubiquitin binds to and activates RIG-I, which is known to trigger the body's when a virus invades a cell.

Dr. Zhijian "James" Chen, professor of molecular biology at UT Southwestern, is senior author of the study, which is available online and in the journal Cell.

Dr. Chen and his colleagues reconstituted key elements of the human innate immune system in laboratory test tubes and found ubiquitin forms a unique chain-like structure that associates with RIG-I before RIG-I can get to work fighting viruses. The innate immune system is the body's first generic response against invading pathogens.

"Activation of RIG-I is the first line of our immune defenses against ," said Dr. Chen, an investigator for the Howard Hughes Medical Institute at UT Southwestern. "Understanding how it comes to life is a key step in developing new approaches to antiviral therapies. Having this test-tube system could help us identify substances that enhance the body's antiviral immunity."

Dr. Chen said his team's experiments mark the first time innate immunity has been recapitulated in a test tube. The findings provide one of the missing pieces in the complex puzzle of how the body fights off infection, he added.

Dr. Chen is now focusing on how activated RIG-I interacts with another protein called MAVS, also essential for .

Explore further: Ultrasound enhancement provides clarity to damaged tendons, ligaments

Related Stories

Flick of a protein switches immune response

Jul 27, 2006

A single protein can turn on and off a key component of the immune system by changing partners in an elegant genomic dance, said researchers at the University of Southern California and Harvard Medical School.

Recommended for you

A better way to track emerging cell therapies using MRIs

Sep 19, 2014

Cellular therapeutics – using intact cells to treat and cure disease – is a hugely promising new approach in medicine but it is hindered by the inability of doctors and scientists to effectively track the movements, destination ...

User comments : 0