Featured Research

from universities, journals, and other organizations

Protein 'Tubules' Free Avian Flu Virus From Immune Recognition

Date:
November 11, 2008
Source:
Baylor College of Medicine
Summary:
A protein found in the virulent avian influenza virus strain called H5N1 forms tiny tubules in which it "hides" the pieces of double-stranded RNA formed during viral infection, which otherwise would prompt an antiviral immune response from infected cells, researchers report.

A protein found in the virulent avian influenza virus strain called H5N1 forms tiny tubules in which it "hides" the pieces of double-stranded RNA formed during viral infection, which otherwise would prompt an antiviral immune response from infected cells, said Baylor College of Medicine researchers in an online report in the journal Nature.

Two domains or portions of the protein NS1 combine to form tiny tubules where double-stranded RNA is hidden from the immune system, said Dr. B. V. Venkataram Prasad, professor of biochemistry and molecular biology, molecular virology and microbiology at BCM and his student, Dr. Zachary A. Bornholdt (now of the Scripps Research Institute in La Jolla, California).

"Once we confirm the importance of this structural information, we should be able to design drugs to block this action," said Prasad. "There are other things the protein could do to interfere with different immune mechanisms. We don't know if this is the only mechanism or if there are others that also come into play during influenza virus infection."

The two researchers had already recognized the importance of the protein NS1 in the virulence of influenza viruses and particularly, H5N1, a form of avian flu associated with more than half the deaths in a 2004 "bird flu" outbreak that resulted in 50 human cases and 36 deaths in Vietnam, China and Thailand. In all but one case, experts ruled out human-to-human spread of the virus. In a previous report, Prasad and Bornholdt described the structure of an area of the protein called the effector domain. In this report, a series of elegant experiments designed and carried out over eight months by Bornholdt allowed the two scientists to "crystallize" the entire protein.

By doing this, they were able to determine its structure using a technique called X-ray crystallography. This technique enables scientists to determine the three-dimensional structure of proteins and other bio-molecules by scattering X-rays through a crystal of the molecule. They substantiated their structure with cryo-electron microscopy, which makes images of tiny frozen structures using an extremely powerful electron microscope.

That structure revealed a previously unsuspected idiosyncrasy of NS1 in H5N1 that could explain the virus' virulence. In most cases, when an infected cell is exposed to a virus, double-stranded RNA molecules are formed triggering a potent anti-viral response that involves production of interferon.

However, the two domains of NS1 in this H5N1 interact to form tiny tubules. The double-stranded RNA is hidden or sequestered in these structures. The cell never sees a significant length of the RNA and does not marshal its immune forces to the fight the virus. Prasad and Bornholdt believe also that cellular factor binding sites found on the surface of the tubules also play a role in fooling the immune system.

"This is only one structure," said Prasad. "We need to see if this holds up with other NS1 structures from other influenza viruses."

Bornholdt's technique for crystallizing the protein will prove valuable in pursuing this work, said Prasad.

"Is this a common mechanism for eluding the immune system?" he said. He said hopes to build a library to NS1 structures to facilitate future studies designed to fight influenza worldwide.

While H5N1 is not usually transmitted from human-to-human at this point, a small change in its genetic structure – perhaps an exchange of genes with a more easily transmitted flu virus – could change that, he said. Developing drugs to fight the virus could prove life-saving in a pandemic.

Funding for this work came from the National Institutes of Health and the Robert Welch Foundation.


Story Source:

The above story is based on materials provided by Baylor College of Medicine. Note: Materials may be edited for content and length.


Cite This Page:

Baylor College of Medicine. "Protein 'Tubules' Free Avian Flu Virus From Immune Recognition." ScienceDaily. ScienceDaily, 11 November 2008. <www.sciencedaily.com/releases/2008/11/081105135235.htm>.
Baylor College of Medicine. (2008, November 11). Protein 'Tubules' Free Avian Flu Virus From Immune Recognition. ScienceDaily. Retrieved September 15, 2014 from www.sciencedaily.com/releases/2008/11/081105135235.htm
Baylor College of Medicine. "Protein 'Tubules' Free Avian Flu Virus From Immune Recognition." ScienceDaily. www.sciencedaily.com/releases/2008/11/081105135235.htm (accessed September 15, 2014).

Share This



More Plants & Animals News

Monday, September 15, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Conservationists Face Uphill PR Battle With New Shark Rules

Conservationists Face Uphill PR Battle With New Shark Rules

Newsy (Sep. 14, 2014) — New conservation measures for shark fishing face an uphill PR battle in the fight to slow shark extinction. Video provided by Newsy
Powered by NewsLook.com
Shocker: Journalists Are Utterly Addicted To Coffee

Shocker: Journalists Are Utterly Addicted To Coffee

Newsy (Sep. 13, 2014) — A U.K. survey found that journalists consumed the most amount of coffee, but that's only the tip of the coffee-related statistics iceberg. Video provided by Newsy
Powered by NewsLook.com
'Magic Mushrooms' Could Help Smokers Quit

'Magic Mushrooms' Could Help Smokers Quit

Newsy (Sep. 11, 2014) — In a small study, researchers found that the majority of long-time smokers quit after taking psilocybin pills and undergoing therapy sessions. Video provided by Newsy
Powered by NewsLook.com
Spinosaurus Could Be First Semi-Aquatic Dinosaur

Spinosaurus Could Be First Semi-Aquatic Dinosaur

Newsy (Sep. 11, 2014) — New research has shown that the Spinosaurus, the largest carnivorous dinosaur, might have been just as well suited for life in the water as on land. Video provided by Newsy
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:
from the past week

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