Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Hide and Seek: Revealing Camouflaged Bacteria

17.04.2014

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.


GTPases (green) attack Salmonella typhimurium (red).

(Figure: University of Basel, Biozentrum)

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.

Original Citation
Etienne Meunier, Mathias S. Dick, Roland F. Dreier, Nura Schürmann, Daniela Kenzelmann Broz, Søren Warming, Merone Roose-Girma, Dirk Bumann, Nobuhiko Kayagaki, Kiyoshi Takeda, Masahiro Yamamoto and Petr Broz
Caspase-11 activation requires lysis of pathogen-containing vacuoles by IFN-induced GTPases
Nature (2014); Advance Online Publication | doi: 10.1038/nature13157

Further Information
Prof. Petr Broz, University of Basel, Biozentrum, phone: +41 61 267 23 42, email: petr.broz@unibas.ch

Heike Sacher | Universität Basel
Further information:
http://www.unibas.ch

Further reports about: Biozentrum Salmonella drugs macrophage mechanisms pathogenic protein responsible strategies

More articles from Life Sciences:

nachricht Closing the carbon loop
08.12.2016 | University of Pittsburgh

nachricht Newly discovered bacteria-binding protein in the intestine
08.12.2016 | University of Gothenburg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Closing the carbon loop

08.12.2016 | Life Sciences

Applicability of dynamic facilitation theory to binary hard disk systems

08.12.2016 | Physics and Astronomy

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>