Featured Research

from universities, journals, and other organizations

How cells recognize viral toxins

Date:
March 26, 2010
Source:
McMaster University
Summary:
New research has identified how specific proteins on the surface of cells, known as class A scavenger receptors, bind to double-stranded RNA and bring it into the cell, jumpstarting the immune response to a virus.

For many years it's been known that the fever, achiness and other symptoms you feel during the flu are triggered by a viral molecule that travels through the body acting like a toxin.

Related Articles


But what scientists haven't understood is how this molecule -- known as double-stranded RNA -- is recognized and taken up by cells.

New research from McMaster University has identified how specific proteins on the surface of cells, known as class A scavenger receptors, bind to double-stranded RNA and bring it into the cell, jumpstarting the immune response to a virus.

This finding, published in the March 26 issue of the journal PLoS Pathogens, could lead to the development of new antiviral therapies.

"Since the 1950s and '60s, it's been known that double-stranded RNA is a viral toxin," said Karen Mossman, an associate professor in the Department of Pathology and Molecular Medicine in the Michael G. DeGroote School of Medicine. "But what we haven't known is how cells recognize double-stranded RNA outside of the cell. We know how they respond to it. We know they take it up. But we've never appreciated how that happens."

Mossman, an investigator with the Michael G. DeGroote Institute for Infectious Disease Research at McMaster University, led a research team to investigate the "gatekeeper" function of scavenger receptors in both human and mouse cells. Until now, it was thought that the role of scavenger receptors was limited to the removal of foreign substances and waste materials from the body.

The researchers examined the five members of the class A scavenger receptor family and discovered that they all had overlapping functions in mediating the response of a cell to double-stranded RNA. They also found that no matter what type of cell they looked at -- including those not thought to express scavenger receptors -- all had at least two or three scavenger receptor family members.

"We found that they are ubiquitously expressed," Mossman said. "But that make sense to us because nearly every cell type responds to double-stranded RNA."

Previously, scavenger receptors were thought to be found only on white blood cells, or macrophages, and a small population of other blood cells. The McMaster research has shown that scavenger receptors are also expressed on fibroblast cells, which play an important role in healing wounds and maintaining the structural framework of tissue.

By identifying these receptors, the researchers have uncovered an ideal target for antiviral drug therapies which could potentially decrease the side effects associated with viral infections.

"Now that we know what to manipulate, we can start looking at how we can manipulate it to be beneficial during a viral infection," Mossman said. "Since all viruses make double-stranded RNA, targeting these receptors should be effective against many different viral infections including influenza and other pandemic viruses."

The research was supported with funds from the National Institutes of Health (NIH) and the Canadian Institutes of Health Research (CIHR).

"Since double-stranded RNA is produced by many different viruses, Dr. Mossman's findings may have a significant impact on the treatment of a wide variety of infections," said Dr. Marc Ouellette, scientific director of the Institute of Infection and Immunity at the Canadian Institutes of Health Research. "Understanding the mechanism employed by viruses to infect surrounding cells is important if we are to develop more effective antiviral therapies, and prevent the spread of viral infections to a wider population."

Stephanie DeWitte-Orr, a postdoctoral fellow in the Mossman lab, was the lead author of the study. The research also involved other collaborators in the Michael G. DeGroote Institute for Infectious Disease Research at McMaster University.


Story Source:

The above story is based on materials provided by McMaster University. Note: Materials may be edited for content and length.


Journal Reference:

  1. DeWitte-Orr et al. An Accessory to the ‘Trinity’: SR-As Are Essential Pathogen Sensors of Extracellular dsRNA, Mediating Entry and Leading to Subsequent Type I IFN Responses. PLoS Pathogens, 2010; 6 (3): e1000829 DOI: 10.1371/journal.ppat.1000829

Cite This Page:

McMaster University. "How cells recognize viral toxins." ScienceDaily. ScienceDaily, 26 March 2010. <www.sciencedaily.com/releases/2010/03/100325214544.htm>.
McMaster University. (2010, March 26). How cells recognize viral toxins. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2010/03/100325214544.htm
McMaster University. "How cells recognize viral toxins." ScienceDaily. www.sciencedaily.com/releases/2010/03/100325214544.htm (accessed October 25, 2014).

Share This



More Plants & Animals News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Black Bear Cub Goes Sunday Shopping

Black Bear Cub Goes Sunday Shopping

Reuters - Light News Video Online (Oct. 23, 2014) Price check on honey? Bear cub startles Oregon drugstore shoppers. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Dances With Wolves in China's Wild West

Dances With Wolves in China's Wild West

AFP (Oct. 23, 2014) One man is on a mission to boost the population of wolves in China's violence-wracked far west. The animal - symbol of the Uighur minority there - is under threat with a massive human resettlement program in the region. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
Breakfast Debate: To Eat Or Not To Eat?

Breakfast Debate: To Eat Or Not To Eat?

Newsy (Oct. 23, 2014) Conflicting studies published in the same week re-ignited the debate over whether we should be eating breakfast. 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:

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