Featured Research

from universities, journals, and other organizations

How mast cells set immune defense on the right track

Date:
June 7, 2010
Source:
Helmholtz Association of German Research Centres
Summary:
Researchers in Germany have now been able to show that previously underrated immune cells, so-called mast cells, decide at a very early stage of an infection which way the defense has to go. They only produce the crucial messenger substance beta-interferon during a viral infection, not during a bacterial infection.

Mast cells with Salmonella bacteria.
Credit: Manfred Rohde, HZI

In the event of an infection, the immune system releases messenger substances. These molecules can either activate immune cells to defeat invading pathogens, or inhibit them to prevent an excessive immune reaction. For this, the immune system has to decide very quickly what mixture of activating and inhibiting messenger molecules leads to a successful defence.

Researchers from the Helmholtz-Centre for Infection Research in Braunschweig, Germany, have now been able to show that hitherto underrated immune cells, so-called mast cells, decide at a very early stage of an infection which way the defence has to go. They only produce the crucial messenger substance beta-interferon during a viral infection, not during a bacterial infection. The reason for this: While on the one hand the molecule always helps to defeat viruses, it hinders on the other hand important immune cells to kill bacteria -- and thus impairs the defence. The group's results have now been published in the Proceedings of the National Academy of Sciences.

Mast cells play a central role during allergic reactions, a function researchers have concentrated on until now. They reside directly under the skin and mucosae, and react immediately when an allergenic substance enters the body. As a result, reddened mucosae, swelling, runny eyes and a runny nose occur. However, mast cells also seem to have a crucial, but only superficially understood, function during pathogenic defence. "They wait precisesly at that position where pathogens enter the body," says Nelson O. Gekara, researcher in the group "Molecular Immunology" at the HZI, "and thus belong to the very first line of immune defence."

To investigate how mast cells react when they come in contact with bacteria and viruses, the HZI-researchers incubated mast cells and pathogens together in a petri dish. Then, they measured what messenger substances the cells produced. As soon as a virus infection occurred, the scientists were then able to detect beta-interferon, produced by the mast cells. Conversely, during a bacterial infection, no beta-interferon was found. "Until now it has been unknown that mast cells can virtually decide whether they produce beta-interferon or not," says Nicole Dietrich who did research on the mast cells. "During a viral infection, beta-interferon helps because it activates mechanisms in surrounding cells that support the virus defence."

The researchers found the reason for why mast cells do not produce beta-interferon during bacterial infections in the defence line that follows mast cells: "Beta-interferon inhibits precisely those cells that quickly eliminate invading bacteria," says Nicole Dietrich. Thus, mast cells determine very early which direction the immune defence is taking.

Important for this decision making are receptors on the surface of all immune cells: So-called "Toll-like receptors" activate mast cells as soon as a pathogen enters the body. When the receptors are triggered, mast cells produce a number of messenger substances that attract cells or keep them at distance, activate or inhibit them and thus regulate an optimised immune response.

"To produce beta-interferon, immune cells have to absorb the receptors and transport them into the cell interior. During a bacterial infection, mast cells refuse to incorporate the receptor and thus do not produce beta-interferon," says Nelson O. Gekara. This is another step towards understanding the complex network of messenger substances, immune cell and pathogen defence. "It seems as if every line of defence can precisely decide which step will be the next and best."


Story Source:

The above story is based on materials provided by Helmholtz Association of German Research Centres. Note: Materials may be edited for content and length.


Journal Reference:

  1. N. Dietrich, M. Rohde, R. Geffers, A. Kroger, H. Hauser, S. Weiss, N. O. Gekara. Mast cells elicit proinflammatory but not type I interferon responses upon activation of TLRs by bacteria. Proceedings of the National Academy of Sciences, 2010; 107 (19): 8748 DOI: 10.1073/pnas.0912551107

Cite This Page:

Helmholtz Association of German Research Centres. "How mast cells set immune defense on the right track." ScienceDaily. ScienceDaily, 7 June 2010. <www.sciencedaily.com/releases/2010/06/100607111308.htm>.
Helmholtz Association of German Research Centres. (2010, June 7). How mast cells set immune defense on the right track. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2010/06/100607111308.htm
Helmholtz Association of German Research Centres. "How mast cells set immune defense on the right track." ScienceDaily. www.sciencedaily.com/releases/2010/06/100607111308.htm (accessed April 23, 2014).

Share This



More Health & Medicine News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Big Pharma Braces for M&A Wave

Big Pharma Braces for M&A Wave

Reuters - Business Video Online (Apr. 22, 2014) Big pharma on the move as Novartis boss, Joe Jimenez, tells Reuters about plans to transform his company via an asset exchange with GSK, and Astra Zeneca shares surge on speculation that Pfizer is looking for a takeover. Joanna Partridge reports. Video provided by Reuters
Powered by NewsLook.com
How Smaller Plates And Cutlery Could Make You Feel Fuller

How Smaller Plates And Cutlery Could Make You Feel Fuller

Newsy (Apr. 22, 2014) NBC's "Today" conducted an experiment to see if changing the size of plates and utensils affects the amount individuals eat. Video provided by Newsy
Powered by NewsLook.com
How to Master Motherhood With the Best Work/Life Balance

How to Master Motherhood With the Best Work/Life Balance

TheStreet (Apr. 22, 2014) In the U.S., there are more than 11 million couples trying to conceive at any given time. From helping celebrity moms like Bethanny Frankel to ordinary soon-to-be-moms, TV personality and parenting expert, Rosie Pope, gives you the inside scoop on mastering motherhood. London-born entrepreneur Pope is the creative force behind Rosie Pope Maternity and MomPrep. She explains why being an entrepreneur offers the best life balance for her and tips for all types of moms. Video provided by TheStreet
Powered by NewsLook.com
Catching More Than Fish: Ugandan Town Crippled by AIDS

Catching More Than Fish: Ugandan Town Crippled by AIDS

AFP (Apr. 22, 2014) The village of Kasensero on the shores of Lake Victoria was where HIV-AIDS was first discovered in Uganda. Its transient population of fishermen and sex workers means the nationwide programme to combat the virus has had little impact. Duration: 02:30 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:
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