Featured Research

from universities, journals, and other organizations

How anthrax bacteria impair immune response

Date:
November 17, 2010
Source:
NIH/National Institute of Allergy and Infectious Diseases
Summary:
Researchers have determined a key mechanism by which Bacillus anthracis bacteria initiate anthrax infection despite being greatly outnumbered by immune system scavenger cells. The finding, made by studying genetically modified mice, adds new detail to the picture of early-stage anthrax infection and supports efforts to develop vaccines and drugs that would block this part of the cycle.

Researchers from the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, have determined a key mechanism by which Bacillus anthracis bacteria initiate anthrax infection despite being greatly outnumbered by immune system scavenger cells. The finding, made by studying genetically modified mice, adds new detail to the picture of early-stage anthrax infection and supports efforts to develop vaccines and drugs that would block this part of the cycle.

To start an infection, anthrax bacteria release a toxin that binds to immune cells through two receptors, TEM8 and CMG2, found on the cell surface. The binding allows two additional bacterial toxins to enter the cells, setting off a chain of events that impairs their ability to ingest and kill the bacteria.

In the new research, NIAID investigators Stephen Leppla, Ph.D., Shihui Liu, M.D., Ph.D., and colleagues bred mice that lacked CMG2 receptors on two kinds of immune cells, neutrophils and macrophages. These usually are the first cells to arrive at the site of an anthrax infection, where they engulf the invading bacteria and try to prevent the spread of infection.

Mice without CMG2 receptors on these immune cells were completely resistant to infection by B. anthracis bacteria, experiencing only a temporary swelling at the site of infection, and fully clearing the infection within two weeks. In contrast, in normal mice, the level of anthrax bacteria increased rapidly in the 48 hours following infection, and all the mice died within six days.

The researchers concluded that B. anthracis uses CMG2 receptors to impair the scavenging action of neutrophils and macrophages during early infection, giving the bacteria time to multiply to levels sufficient to overwhelm the body's defenses. Developing drugs and vaccines that block B. anthracis from establishing early infection via binding to the CMG2 receptor, say the study authors, may be crucial to success in treating and preventing anthrax disease.


Story Source:

The above story is based on materials provided by NIH/National Institute of Allergy and Infectious Diseases. Note: Materials may be edited for content and length.


Journal Reference:

  1. S Liu et al. Anthrax toxin targeting of myeloid cells through the CMG2 receptor is essential for establishment of Bacillus anthracis infections in mice. Cell Host and Microbe, 2010 DOI: 10.1016/j.chom.2010.10.004

Cite This Page:

NIH/National Institute of Allergy and Infectious Diseases. "How anthrax bacteria impair immune response." ScienceDaily. ScienceDaily, 17 November 2010. <www.sciencedaily.com/releases/2010/11/101117121759.htm>.
NIH/National Institute of Allergy and Infectious Diseases. (2010, November 17). How anthrax bacteria impair immune response. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2010/11/101117121759.htm
NIH/National Institute of Allergy and Infectious Diseases. "How anthrax bacteria impair immune response." ScienceDaily. www.sciencedaily.com/releases/2010/11/101117121759.htm (accessed October 20, 2014).

Share This



More Plants & Animals News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

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
Traditional Farming Methods Gaining Ground in Mali

Traditional Farming Methods Gaining Ground in Mali

AFP (Oct. 20, 2014) He is leading a one man agricultural revolution in Mali - Oumar Diatabe uses traditional farming methods to get the most out of his land and is teaching others across the country how to do the same. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
Goliath Spider Will Give You Nightmares

Goliath Spider Will Give You Nightmares

Buzz60 (Oct. 20, 2014) An entomologist stumbled upon a South American Goliath Birdeater. With a name like that, you know it's a terrifying creepy crawler. Sean Dowling (@SeanDowlingTV) has the details. Video provided by Buzz60
Powered by NewsLook.com
Adorable Video of Baby Rhino and Lamb Friend Playing

Adorable Video of Baby Rhino and Lamb Friend Playing

Buzz60 (Oct. 20, 2014) Gertjie the Rhino and Lammie the Lamb are teaching the world about animal conservation and friendship. TC Newman (@PurpleTCNewman) has the adorable video! Video provided by Buzz60
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