Featured Research

from universities, journals, and other organizations

Scientists reveal natural process that blocks viruses

Date:
April 17, 2013
Source:
University of Southern California - Health Sciences
Summary:
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 hold promise for the development of therapies to fight a variety of viral infections.

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 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."


Story Source:

The above story is based on materials provided by University of Southern California - Health Sciences. Note: Materials may be edited for content and length.


Journal Reference:

  1. Samad Amini-Bavil-Olyaee, YounJung Choi, JunHan Lee, Mude Shi, I-Chueh Huang, Michael Farzan, JaeU. Jung. The Antiviral Effector IFITM3 Disrupts Intracellular Cholesterol Homeostasis to Block Viral Entry. Cell Host & Microbe, 2013; 13 (4): 452 DOI: 10.1016/j.chom.2013.03.006

Cite This Page:

University of Southern California - Health Sciences. "Scientists reveal natural process that blocks viruses." ScienceDaily. ScienceDaily, 17 April 2013. <www.sciencedaily.com/releases/2013/04/130417130744.htm>.
University of Southern California - Health Sciences. (2013, April 17). Scientists reveal natural process that blocks viruses. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2013/04/130417130744.htm
University of Southern California - Health Sciences. "Scientists reveal natural process that blocks viruses." ScienceDaily. www.sciencedaily.com/releases/2013/04/130417130744.htm (accessed October 22, 2014).

Share This



More Plants & Animals News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Cadaver Dogs Aid Search for More Victims of Suspected Indiana Serial Killer

Cadaver Dogs Aid Search for More Victims of Suspected Indiana Serial Killer

Reuters - US Online Video (Oct. 21, 2014) Police in Gary, Indiana are using cadaver dogs to search for more victims after a suspected serial killer confessed to killing at least seven women. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
White Lion Cubs Unveiled to the Public

White Lion Cubs Unveiled to the Public

Reuters - Light News Video Online (Oct. 21, 2014) Visitors to Belgrade zoo meet a pair of three-week-old lion cubs for the first time. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
'Cadaver Dog' Sniffs out Human Remains

'Cadaver Dog' Sniffs out Human Remains

AP (Oct. 21, 2014) Where's a body buried? Buster's nose can often tell you. He's a cadaver dog, specially trained to find human remains and increasingly being used by law enforcement and accepted in courts. These dogs are helping solve even decades-old mysteries. (Oct. 21) Video provided by AP
Powered by NewsLook.com
White Lion Cubs Born in Belgrade Zoo

White Lion Cubs Born in Belgrade Zoo

AFP (Oct. 20, 2014) Two white lion cubs, an extremely rare subspecies of the African lion, were recently born at Belgrade Zoo. They are being bottle fed by zoo keepers after they were rejected by their mother after birth. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins