Navigation Links
University of Southern California scientists reveal natural process that blocks viruses

The human body has the ability to ward off viruses by activating a naturally occurring protein at the cellular level, setting off a chain reaction that disrupts the levels of cholesterol required in cell membranes to enable viruses to enter cells. The findings, discovered by researchers in molecular microbiology and immunology at the Keck School of Medicine of USC, hold promise for the development of therapies to fight a variety of viral infections.

"Previous studies have shown that our bodies are already equipped to block viruses such as Ebola, influenza, West Nile, and SARS," said Jae U. Jung, principal investigator and distinguished professor and chair of the Molecular Microbiology and Immunology Department. The study, "The antiviral effector IFITM3 disrupts intracellular cholesterol homeostasis to block viral entry," was published in the journal Cell Host & Microbe on April 17, 2013.

"We showed how this occurs," Jung said. "When a virus tries to enter, the immune system gets stimulated by interferon, which produces almost 300 host proteins, including IFITM3. This protein then disrupts the interaction between two other proteins, which, in turn, significantly increases the level of cholesterol in cells, and thereby blocks the virus."

Jung added that the increase in cholesterol is only within the endosome compartment of cells and has no impact on or effect from the level of cholesterol in the bloodstream.

Joining Jung in the study were Samad Amini-Bavil-Olyaee, Keck School postdoctoral research associate and first author of the paper, as well as Youn Jung Choi, Keck School graduate student and second author, and researchers from the University of California, Riverside and Scripps Research Institute. The research was funded by the National Institutes of Health (grants CA082057, CA31363, CA115284, DE019085, AI073099, AI083025, HL110609) and the Fletcher Jones Foundation.

Scientists long have known that interferon, a protein released by the body's cells and named after its ability to "interfere" with viral replication, can inhibit the spread of viruses, but didn't understand how. The Keck School investigators found that interferon-inducible transmembrane protein 3 (IFITM3) can disrupt the interaction between Vesicle-membrane-associated protein (VAPA) and oxysterol-binding protein (OSBP) that regulates the transport and stability of cholesterol, which are required for many viruses to take hold.

One of the main goals of his lab, Jung said, is to understand how the immune system recognizes viruses and blocks entry. In previous research, he and his colleagues have shown that a specific immune protein recognizes genetic information of the virus and then sets off an alarm signal in the host immune system.

Jung explained that in the most recent investigation, the rise in cholesterol was found to occur in the endosome compartment within the cell membrane. "The membrane is usually very flexible," he said. "With an increase in cholesterol it becomes rigid, and doesn't allow viruses to pass through the endosome compartment into cytosol, the fluid portion inside cells. We were surprised to find that changing the balance of cholesterol concentration affects viral entry."

The next step, he said, "will be to identify a therapeutic molecule that activates the expression and function of the IFITM3 protein, which potentially can be used to create an anti-viral therapy. It could target the endosome compartment in order to control, combat, or prevent the spread of viral infection."


Contact: Leslie Ridgeway
University of Southern California - Health Sciences

Related biology news :

1. University of Houston engineering researchers theories to be tested in space
2. University of Tennessee professors research shows Gulf of Mexico resilient after spill
3. Mercyhurst Universitys new DNA sequencer to accelerate scientific research in region
4. Student named universitys first Lawrence scholar, researching at national laboratory
5. University of Tennessee professor links massive prehistoric bird extinction to human colonization
6. University of Montreal researchers discover how drug prevents aging and cancer progression
7. University of Californias unofficial favorite sea slug poised to make a comeback
8. University of Maryland School of Medicine finds depression stems from miscommunication between brain cells
9. Columbia University Medical Center/NY-Presbyterian experts at AAN
10. Eurofins MWG Operon and Queen Mary, University Of London commence genome sequencing analysis of Ash
11. University of Maryland School of Medicine discovers adaptations to explain strategies for survival on Mars
Post Your Comments:
(Date:10/29/2015)... Oct. 29, 2015  Connected health pioneer, Joseph ... explosion of technology-enabled health and wellness, and the business ... The Internet of Healthy Things . ... smartphones even existed, Dr. Kvedar, vice president, Connected Health, ... care delivery, moving care from the hospital or doctor,s ...
(Date:10/27/2015)... , Oct. 27, 2015 In the ... issues of concern for various industry verticals such as ... due to the growing demand for secure & simplified ... various ,sectors, such as hacking of bank accounts, misuse ... electronic equipment such as PC,s, laptops, and smartphones are ...
(Date:10/26/2015)... , October 26, 2015 /PRNewswire/ ... --> adds Biometrics ... to 2021 as well as Emerging ... research reports to its collection of ... . --> ...
Breaking Biology News(10 mins):
(Date:12/1/2015)... 2015 ) ... U.K. Virology and Bacteriology Testing Market: Sales ... Supplier Shares by Test, Innovative Technologies, Competitive ... --> ) has announced ... and Bacteriology Testing Market: Sales and Volume ...
(Date:11/30/2015)... ... November 30, 2015 , ... Global Stem Cells ... stages of a new closed system for isolating adipose-derived stem cells. The announcement starts ... (SVF) of adipose tissue. SVF is a component of the lipoaspirate obtained from liposuction ...
(Date:11/30/2015)... ... 2015 , ... Global Stem Cells Group announced the opening of a new core ... and Iquique in northern Chile. The facilities are part of GSCG’s expansion efforts in Latin ... techniques in stem cell medicine to patients from around the world. , The clinics will ...
(Date:11/30/2015)... (NYSE: BIOA ), a leader in renewable materials, today ... Climate Pledge, alongside more than 140 companies from across the ... demonstrate an ongoing commitment to climate action and to voice ... Paris climate negotiations. Sarnia, Canada ... --> BioAmber uses biotechnology to convert renewable sugars ...
Breaking Biology Technology: