Inflammatory diseases: Scientists identify antiviral defense

Jun 15, 2010

Canadian researchers have discovered a new way the body combats respiratory viral infections. In the prestigious journal PLoS Pathogens, scientists from the University of Montreal and the University of Montreal Hospital Research Center explain how the NOX2 molecule, an enzyme that generates a burst of highly reactive oxygen derivatives (or free radicals), activates defense genes and molecules when viruses invade lung cells.

"The expression 'free radicals' is often associated with nasty molecules we've been told to guard against by eating fruits and vegetables that are high in so-called antioxidants - molecules that can neutralize these free radicals. It turns out that our own cells generate free radicals when invaded by viruses; these serve a critical role when our cells mount an immune response to viral invasions," says senior author and biochemistry professor Nathalie Grandvaux of the University of Montreal and a scientist at the University of Montreal Hospital Research Center.

The University of Montreal study builds on previous research that shows human cells contain key sensor molecules that detect virus invasions. Sensor molecules, including RIG-I and Mda-5, were found to bind to a molecule called MAVS when they sense a virus. This process unleashes a signaling cascade, or a series of , which turns on antiviral genes. Until now, however, it was unclear how the process occurs.

Dr. Grandvaux and her colleagues were able to show that airway cells contain an enzyme called NOX2 that snatches oxygen from the surrounding air and converts it into highly reactive free radicals. Instead of ravaging cells, these free radicals react with other molecules to drive production and maintain the stability of MAVS molecule to essential levels. This leads to a chemical cascade that activates genes needed to mount an antiviral response.

Although the research team did find that free radicals are beneficial, they can sometimes be too much of a good thing. "In the presence of a virus, NOX2 also controls inflammation in our airways, which when excessive causes virus-associated respiratory problems, including bronchiolitis or on a long-term basis, asthma," says Dr. Grandvaux. "NOX2 is a prime target for drugs being developed to combat such inflammatory diseases. Indeed, a related enzyme called NOX1 is also being targeted against inflammatory diseases of the digestive tract."

Explore further: US scientists make embryonic stem cells from adult skin

More information: PLoS Pathogens article: www.plospathogens.org/article/info%3Adoi%2F10.1371%2Fjournal.ppat.1000930

add to favorites email to friend print save as pdf

Related Stories

Antioxidant to retard wrinkles discovered

Aug 30, 2007

A new method for fighting skin wrinkles has been developed at the Hebrew University Faculty of Agriculture, Food and Environmental Quality Sciences.

New agent strikes at respiratory syncytial virus replication

May 05, 2008

University of Texas Medical Branch at Galveston researchers have achieved promising results with a potential new weapon against respiratory syncytial virus, the most common cause of infant hospitalization in the United States.

Recommended for you

Leeches help save woman's ear after pit bull mauling

Apr 18, 2014

(HealthDay)—A pit bull attack in July 2013 left a 19-year-old woman with her left ear ripped from her head, leaving an open wound. After preserving the ear, the surgical team started with a reconnection ...

New pain relief targets discovered

Apr 17, 2014

Scientists have identified new pain relief targets that could be used to provide relief from chemotherapy-induced pain. BBSRC-funded researchers at King's College London made the discovery when researching ...

User comments : 0

More news stories

Treating depression in Parkinson's patients

A group of scientists from the University of Kentucky College of Medicine and the Sanders-Brown Center on Aging has found interesting new information in a study on depression and neuropsychological function in Parkinson's ...

Airbnb rental site raises $450 mn

Online lodging listings website Airbnb inked a $450 million funding deal with investors led by TPG, a source close to the matter said Friday.

Health care site flagged in Heartbleed review

People with accounts on the enrollment website for President Barack Obama's signature health care law are being told to change their passwords following an administration-wide review of the government's vulnerability to the ...