Featured Research

from universities, journals, and other organizations

Timing, duration of biochemical bugle call critical for fighting viruses

Date:
June 13, 2012
Source:
Washington University School of Medicine
Summary:
Researchers have identified the primary player of the biochemical bugle call that musters the body's defenders against viral infection.

Researchers have identified the primary player of the biochemical bugle call that musters the body's defenders against viral infection.

Scientists at Washington University School of Medicine in St. Louis have shown that a key molecule, MDA5, is essential for producing enough interferon (the bugle call) to rally virus-fighting cells during certain viral infections. In mice, the lack of MDA5 forces the immune system to rely on less effective defenders, which may give the virus opportunities to establish or expand a chronic infection.

Like the cavalry charge in classic movies, timing is critical in fighting a viral infection. If a surge of interferon comes early enough, the immune system can limit or clear a virus. If the boost is too late, though, the defenses may already be overwhelmed.

"If an injection of interferon is given within a certain time frame in the infectious process, we found that it was possible to decrease viral spread and bolster antiviral CD8 T cell responses in our mouse model," says first author Yaming Wang, a predoctoral trainee in immunobiology. "Adding interferon may also boost the power of antiviral vaccines that are being designed to help the immune system recognize and attack chronic viral infections such as HIV."

The research appears June 14 in Cell Host and Microbe.

Viruses can cause both temporary and chronic infections. In chronic infections, the virus goes into periods of relative quiescence that limit its spread and diminish conflicts with the immune system. Those periods are often interrupted by flare-ups when the virus shifts gears and becomes more active again.

Interferon, which is made by the body in many forms, is named for its ability to interfere with viral replication. It is currently used with antiviral medications to treat patients with hepatitis C who are having flare-ups.

"Interferon puts cells into an antiviral state," says senior author Marco Colonna, MD, professor of medicine and of pathology and immunology. "This prevents viruses from infecting cells or reproducing in them."

Some forms of interferon also summon critical immune CD8 T cells to infection sites, where the T cells either fight the infection directly or store information about the virus to speed recognition if it returns.

Wang and his colleagues showed that MDA5 is the major source of interferon during a meningitis-type infection known as lymphocytic choriomeningitis virus.

Interferon production by a specialized immune cell, the plasmacytoid dendritic cell, dropped off rapidly within the first day of infection, but MDA5 continued to boost interferon production for three to four days.

Prolonging interferon production allows infection-fighting cells to stay in the battle longer, but also increases the risk that those same cells could cause autoimmune damage. The results suggest that timing and balance are critical, according to co-author Melissa Swiecki, PhD, a postdoctoral research associate.

"As we consider the implications of these results for expanding or refining our use of interferon in the clinic, timing and magnitude are going to be the key words. Can we find ways to get patients interferon when they need it and in just the right amount?" Swiecki says.

Colonna and his colleagues are planning follow-up studies in humans.


Story Source:

The above story is based on materials provided by Washington University School of Medicine. The original article was written by Michael C. Purdy. Note: Materials may be edited for content and length.


Journal Reference:

  1. Yaming Wang, Melissa Swiecki, Marina Cella, Gottfried Alber, RobertD. Schreiber, Susan Gilfillan, Marco Colonna. Timing and Magnitude of Type I Interferon Responses by Distinct Sensors Impact CD8T Cell Exhaustion and Chronic Viral Infection. Cell Host & Microbe, 2012; 11 (6): 631 DOI: 10.1016/j.chom.2012.05.003

Cite This Page:

Washington University School of Medicine. "Timing, duration of biochemical bugle call critical for fighting viruses." ScienceDaily. ScienceDaily, 13 June 2012. <www.sciencedaily.com/releases/2012/06/120613133349.htm>.
Washington University School of Medicine. (2012, June 13). Timing, duration of biochemical bugle call critical for fighting viruses. ScienceDaily. Retrieved September 16, 2014 from www.sciencedaily.com/releases/2012/06/120613133349.htm
Washington University School of Medicine. "Timing, duration of biochemical bugle call critical for fighting viruses." ScienceDaily. www.sciencedaily.com/releases/2012/06/120613133349.htm (accessed September 16, 2014).

Share This



More Health & Medicine News

Tuesday, September 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

President To Send 3,000 Military Personnel To Fight Ebola

President To Send 3,000 Military Personnel To Fight Ebola

Newsy (Sep. 16, 2014) President Obama is expected to send 3,000 troops to West Africa as part of the effort to contain Ebola's spread. Video provided by Newsy
Powered by NewsLook.com
Man Floats for 31 Hours in Gulf Waters

Man Floats for 31 Hours in Gulf Waters

AP (Sep. 16, 2014) A Texas man is lucky to be alive after he and three others floated for more than a day in the Gulf of Mexico when their boat sank during a fishing trip. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

AFP (Sep. 16, 2014) Since the arrival of Ebola in Ivory Coast, Ivorians have been abandoning their pets, particularly monkeys, in the fear that they may transmit the virus. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com
Study Links Male-Pattern Baldness To Prostate Cancer

Study Links Male-Pattern Baldness To Prostate Cancer

Newsy (Sep. 16, 2014) New findings suggest men with a certain type of baldness at age 45 are 39 percent more likely to develop aggressive prostate cancer. 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