Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Waiting for the right moment

26.08.2010
Bacterial pathogens delay their entry into cells

Pathogens make themselves feel at home in the human body, invading cells and living off the plentiful amenities on offer. However, researchers at the Max Planck Institute for Infection Biology, Berlin, together with colleagues at Harvard University, reveal an opposite strategy used to ensure infection success. Pathogens can actually delay their entry into cells to ensure their survival. Upon cell contact, bacteria trigger a local strengthening of the cellular skeleton with the aid of signalling molecules, allowing them to remain outside the cell. The researchers also show that this strategy, unknown until now, is used by certain intestinal pathogens as well. (PLoS Biology, 24th of August 2010)


Neisseria gonorrhoeae bacteria, forming micro-colonies on the surface of a human cell, stimulate signals to stabilize their extracellular life style. Image: Max Planck Institute for Infection Biology

Infection with the sexually transmitted bacterium Neisseria gonorrhoeae can lead to an inflammation of the urogenital tract, the uterus and ovaries. By means of thread-shaped proteins on its surface called pili, the bacterium attaches itself to the cell membrane. Once attached, the bacteria undergo rapid changes of their surface structure to avoid recognition by the host’s immune system. Only during the later stages of infection will the pathogens penetrate cells and occasionally advance into deeper tissues to find further breeding ground.

Until now scientists were firmly focused on understanding the tricks used by these pathogens to enter cells. The results of the Berlin-based researchers suggest, however, that bacteria may spend as much effort in resisting cell entry. Host cells tend to generate tiny vesicles by which they transport bacteria inadvertently into the interior. The researchers have now shed some light on the signals which prevent the bacteria from being ‘swallowed’. Upon fastening themselves to the cell surface, the bacteria induce a sequence of events that results in the strengthening of the cell skeleton directly beneath the point of attachment. The structural protein Actin is transported to attachment sites, where it forms a strong, supportive chain. In tandem, another structural protein Caveolin-1 and the signalling proteins VAV2 and RhoA are recruited to the cell membrane where they play a central role in effectively maintaining N. gonorrhoeae in the extracellular milieu.

Better outside than inside

These results have opened up new perspectives in understanding the course of infections: "For a long time it was thought that most pathogens strive to enter cells quickly. However, the opposite may be the case. It seems the bacteria prolong their extracellular existence in order to survive", declares Thomas F. Meyer of the Max Planck Institute of Infection Biology. By anchoring to the cell via pili proteins and assembling an underlying support skeleton, the pathogen is buffered against the often inhospitable conditions of the extracellular environment.

By extrapolating their findings to the intestinal bacteria Escherichia coli, the scientists have indicated that the strategy of delaying entry into cells to ensure survival may be widespread among pathogens, possibly even the bacterial agents of meningitis and pneumonia. These newly discovered signalling pathways may therefore have exciting implications for the prevention of infection.

Original work:

Jan Peter Boettcher, Marieluise Kirchner, Yuri Churin, Alexis Kaushansky, Malvika Pompaiah, Hans Thorn, Volker Brinkmann, Gavin MacBeath, Thomas F. Meyer
Tyrosine-phosphorylated caveolin-1 blocks bacterial uptake by inducing Vav2-RhoA-mediated cytoskeletal rearrangements

PLoS Biology, August 24, 2010

Contact:

Prof. Dr. Thomas F. Meyer
Max Planck Institute for Infection Biology, Berlin
Tel.: +49 30 28 460-400
E-mail: meyer@mpiib-berlin.mpg.de

Barbara Abrell | EurekAlert!
Further information:
http://www.mpg.de/english/

More articles from Life Sciences:

nachricht New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg

nachricht Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>