Navigation Links
Molecular ‘On/Off Switch’ Controls Immune Defenses Against Viruss

Much like flipping a light switch, the hepatitis C virus turns on human immune defenses upon entering the body //but also turns off those defenses by manipulating interaction of key cellular proteins, UT Southwestern Medical Center researchers have found.

This same molecular “on/off switch” controls immunity against many viruses, highlighting a potential new target for novel therapeutics to fight viruses, the researchers report.

In a study available online this week and in an upcoming issue of the Proceedings of the National Academy of Sciences, UT Southwestern scientists describe how the proteins RIG-I and LGP2 normally interact to turn on and off immune response to hepatitis C.

It’s known that when a virus invades a cell, the RIG-I protein triggers the body to generate an immune response. Once the virus has been cleared out, the LGP2 protein turns off the RIG-I signals.

This interaction between RIG-I and LGP2 is vital for properly regulating immunity, but viruses such as hepatitis C can disrupt the normal process to shut down immune defenses early, the research team found.

“This knowledge will help us design drugs that mimic the viral effects on these proteins to either activate a host’s immune response or shut it down,” said Dr. Michael Gale, associate professor of microbiology and the study’s senior author. “This holds great potential in developing new disease therapies, because the tactics employed by hepatitis C to trigger immune response are similar to those employed by other viruses such as West Nile, influenza and the common cold.”

Dr. Gale’s research centers on studying the mechanisms viruses use to evade immune defenses. Of particular interest is the hepatitis C virus, a blood-borne infection transmitted by intravenous drug use, blood transfusions and sexual contact. It affects 4 million U.S. residents and is the nation’s leading cause of cirrhosis and liver cancer.

In 2005 Dr. Gale and his team completed several breakthrough studies on hepatitis C, discovering that the RIG-I protein binds to viral genetic material. Then, RIG-I changes its shape and sends signals to other proteins that spur production of interferon, a molecule that stops viral replication. The researchers also found that the virus launches a counterattack on RIG-I, producing a protein called a protease to disrupt the signaling process, preventing interferon production and allowing viral replication.

Just how RIG-I signaling is normally regulated, however, hadn’t been known.

In the current study, UT Southwestern researchers found that RIG-I and LGP2 each contain a repressor domain, a sort of docking site that controls the actions of each protein. The domain is the key site that regulates the ability of RIG-I to bind to its signaling partners, including LGP2, acting as a switch for controlling immune response, Dr. Gale said.

“Hepatitis C and others viruses hijack this signaling pathway to stop immune defenses,” he said.

His research team and others are working to design novel therapeutics and drugs that could mimic viral effects on RIG-I to spur antiviral response or, conversely, mimic viral effects on LGP2 to shut down RIG-I activity. RIG-I shutdown would be necessary in cases when the immune system’s response to a virus is dangerously overactive, which happened in many flu cases during the 1918 pandemic.

“Fine-tuning immune response to infection is where antiviral or immune regulatory drugs are headed,” said Dr. Gale.


Related medicine news :

1. Molecular markers for early diagnosis of breast and ovarian cancer
2. Scientists Developed Map For Brain Molecular Communities
3. Molecular Mechanism Of HIV Infecting The Healthy Cells Discovered.
4. Molecular Flaw Detected in Aggressive Breast Cancers
5. Molecular Computer Developed To perform Calculations From Within Human Body
6. Molecular Imaging Of Cancer Now Possible, New Hybrid Virus Produced
7. Molecular Basis Of ALS Found
8. New Molecular Treatment Identified To Treat Blood Cell Cancers
9. Researchers Find Molecular "Brake" to Cell Death
10. Solitons Could Power Molecular Electronics, Artificial Muscles
11. Discovery of Agile Molecular Motors Could Aid in Treating Motor Neuron Diseases
Post Your Comments:

(Date:6/25/2016)... ... ... As a lifelong Southern Californian, Dr. Omkar Marathe earned his Bachelors in ... School of Medicine at UCLA. He trained in Internal Medicine at Scripps Green Hospital ... at the UCLA-Olive View-Cedars Sinai program where he had the opportunity to train in ...
(Date:6/25/2016)... ... June 25, 2016 , ... On Friday, June 10, Van Mitchell, ... at Work award to iHire in recognition of their exemplary accomplishments in worksite health ... annual Maryland Workplace Health & Wellness Symposium at the BWI Marriott in Linthicum Heights. ...
(Date:6/24/2016)... CA (PRWEB) , ... June 24, 2016 , ... A ... procedures that most people are unfamiliar with. The article goes on to state that ... but also many of these less common operations such as calf and cheek reduction. ...
(Date:6/24/2016)... ... 24, 2016 , ... June 19, 2016 is World Sickle Cell Observance Day. ... the benefits of holistic treatments, Serenity Recovery Center of Marne, Michigan, has ... , Sickle Cell Disease (SCD) is a disorder of the red blood cells, which ...
(Date:6/24/2016)... ... June 24, 2016 , ... ... Sessions in Dallas that it will receive two significant new grants to support ... as PHA marked its 25th anniversary by recognizing patients, medical professionals and scientists ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... BOGOTA, Colombia , June 23, 2016  Astellas today announced the establishment of Astellas Farma Colombia (AFC), a ... second affiliate in Latin America . ... ... ... ...
(Date:6/23/2016)... , June 23, 2016  Guerbet announced today ... Inc.,s Supplier Horizon Award . One ... Guerbet was recognized for its support of Premier members ... through clinical excellence, and commitment to lower costs. ... receive this recognition of our outstanding customer service from ...
(Date:6/23/2016)... 23, 2016 Research and Markets ... Volumes: Global Analysis (United States, China, Japan, Brazil, United ... to their offering. ... healthcare business planners, provides surgical procedure volume data in ... with an in-depth analysis of growth drivers and inhibitors, ...
Breaking Medicine Technology: