Featured Research

from universities, journals, and other organizations

Hide and seek: Revealing camouflaged bacteria

Date:
April 16, 2014
Source:
University of Basel
Summary:
A protein family that plays a central role in the fight against the bacterial pathogen Salmonella within the cells has been discovered by researchers. The so called interferon-induced GTPases reveal and eliminate the bacterium's camouflage in the cell, enabling the cell to recognize the pathogen and to render it innocuous.

GTPases (green) attack Salmonella typhimurium (red).
Credit: University of Basel, Biozentrum

A research team at the Biozentrum of the University of Basel has discovered an protein family that plays a central role in the fight against the bacterial pathogen Salmonella within the cells. The so called interferon-induced GTPases reveal and eliminate the bacterium's camouflage in the cell, enabling the cell to recognize the pathogen and to render it innocuous. The findings are published in the current issue of the science magazine Nature.

Bacteria have developed countless strategies to hide themselves in order to evade attack by the immune system. In the body, Salmonella bacteria use macrophages as host cells to ensure their survival and to be able to spread within the body. Their survival strategy is to nestle into a vacuole within the cytoplasm of a macrophage, hiding there and multiplying. While they are hidden there, the immune cells cannot detect the bacteria and fight them.

Exposure: GTPases destroy Salmonella's hideout

The macrophages, in which the Salmonella hide, however, have also developed a strategy to unmask the disguise of the bacterium and uncover its hiding place. Prof. Petr Broz's research group at the Biozentrum of the University of Basel has discovered a protein family called interferon-induced GTPases in host cells invaded by Salmonella. "They are responsible for destroying the hiding place of the pathogen and to initiate the immune response of the cell," explains Etienne Meunier, first author of the publication.

Destruction: Kick-off for attacking the bacteria

Once the hiding place has been discovered, GTPases are transported to the vacuole and destabilize its membrane. The bacteria are left behind unprotected in the cytoplasm where their surface molecules are easily recognized by the intracellular defense. "The GTPases are the key to the hiding place of the bacteria. Once the door has been opened and the protective vacuole destroyed, there is no escape. The bacteria are immediately exposed to the defense machinery of the cell," says Meunier. Receptors in the cell identify the pathogen, which then activate special cellular enzymes to destroy the bacteria. In addition, the cells own proteases, so-called caspases, are activated and trigger cell death of the infected host cell.

Salmonella still remain a feared pathogenic agent, as they can cause life threatening diarrheal disease. The findings of Broz and his team enable the better understanding of the strategies of the immune cells and to perhaps model this in the future. The deeper understanding of the immune response of our cells also paves the way for new approaches in using drugs to support the body's fight against pathogens. In order to further elucidate the mechanisms of the immune response to Salmonella infections, the research team plans to investigate how cells detect the hiding place of the bacteria, the vacuole in the cytoplasm of the macrophages, and what initiates the recruitment of GTPases to the vacuole.


Story Source:

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


Journal Reference:

  1. Etienne Meunier, Mathias S. Dick, Roland F. Dreier, Nura Schόrmann, Daniela Kenzelmann Broz, Sψren Warming, Merone Roose-Girma, Dirk Bumann, Nobuhiko Kayagaki, Kiyoshi Takeda, Masahiro Yamamoto, Petr Broz. Caspase-11 activation requires lysis of pathogen-containing vacuoles by IFN-induced GTPases. Nature, 2014; DOI: 10.1038/nature13157

Cite This Page:

University of Basel. "Hide and seek: Revealing camouflaged bacteria." ScienceDaily. ScienceDaily, 16 April 2014. <www.sciencedaily.com/releases/2014/04/140416133338.htm>.
University of Basel. (2014, April 16). Hide and seek: Revealing camouflaged bacteria. ScienceDaily. Retrieved August 27, 2014 from www.sciencedaily.com/releases/2014/04/140416133338.htm
University of Basel. "Hide and seek: Revealing camouflaged bacteria." ScienceDaily. www.sciencedaily.com/releases/2014/04/140416133338.htm (accessed August 27, 2014).

Share This




More Health & Medicine News

Wednesday, August 27, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Predicting Heart Transplant Rejection With a Blood Test

Predicting Heart Transplant Rejection With a Blood Test

Ivanhoe (Aug. 27, 2014) — Now a new approach to rejection of donor organs could change the way doctors predict transplant rejection…without expensive, invasive procedures. Video provided by Ivanhoe
Powered by NewsLook.com
Better Braces That Vibrate

Better Braces That Vibrate

Ivanhoe (Aug. 27, 2014) — The length of time you have to keep your braces on could be cut in half thanks to a new device that speeds up the process. Video provided by Ivanhoe
Powered by NewsLook.com
Smartphone App Tracks Your Heart Rate

Smartphone App Tracks Your Heart Rate

Ivanhoe (Aug. 27, 2014) — A new app that can track your heart rate 24/7 is available for download in your app store and its convenience could save your life. Video provided by Ivanhoe
Powered by NewsLook.com
Stroke in Young Adults

Stroke in Young Adults

Ivanhoe (Aug. 27, 2014) — A stroke can happen at any time and affect anyone regardless of age. This mother chose to give her son independence and continue to live a normal life after he had a stroke at 18 years old. Video provided by Ivanhoe
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