Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Invasion without a stir

21.12.2009
HZI researchers redefine the invasion mechanism of Salmonella

"Based on our data, the molecular mechanism of infection employed by Salmonella has to be revised," says Klemens Rottner, head of the HZI research group "Cytoskeleton Dynamics". The group's results have now been published in the current issue of the scientific journal "Cellular Microbiology".

Salmonella are highly adaptive bacteria. They can live in the presence and absence of oxygen and thus propagate in the gut. The ingestion by humans occurs mainly via contaminated egg dishes such as mayonnaise or raw milk products as well as meat or sausages. Infections with Salmonella lead to severe diarrhea and fever, particularly in patients harbouring a compromised immune system.

Although Salmonella are long-known pathogens, the precise mechanisms of infection are incompletely understood. The bacteria inject a protein cocktail using a "molecular syringe" into host cells, leading to dramatic rearrangements of cytoskeletal filaments below the cell membrane. As a result, membrane waves are formed, which enclose the bacteria, and apparently facilitate their invasion. Those characteristic membrane waves are called "ruffles", the process is known as "ruffling". Until now, researchers regarded the formation of these ruffles as absolutely essential for bacterial entry.

In a collaborative effort, HZI research groups "Cytoskeleton dynamics" and "Signalling and Motility" now succeeded in shedding new light on the infection strategy of Salmonella. "We wanted to improve our mechanistic understanding of how Salmonella invade their host cells," says Jan Hänisch, who performed most experiments in the course of his PhD-thesis. Cells that were engineered to lack those membrane ruffles normally induced during Salmonella infection still engulfed the bacteria. "We showed for the first time that membrane ruffles are not essential for the bacteria to penetrate the host cell membrane." Since ruffling was used so far as signature of successful host cell invasion by this pathogen, the usefulness of such methods has to be reconsidered.

Finally, the researchers discovered a new piece in the puzzle of Salmonella entry, called WASH. This novel factor promotes bacterial invasion by contributing to the formation of host cell cytoskeletal filaments important for entry. "Our results have significant impact on the molecular and mechanistic understanding of the infection strategy used by this pathogen," says Rottner, "and on the development of novel strategies to screen for potential inhibitors of the entry process in the future."

Original article: Molecular dissection of Salmonellen-induced membrane ruffling versus invasion. Hänisch J, Ehinger J, Ladwein M, Rohde M, Derivery E, Bosse T, Steffen A, Bumann D, Misselwitz B, Hardt WD, Gautreau A, Stradal TE, Rottner K. Cell Microbiol. (2010) 12(1), 84. doi:10.1111/j.1462-5822.2009.01380.x

Dr. Bastian Dornbach | EurekAlert!
Further information:
http://www.helmholtz-hzi.de

Further reports about: HZI Invasion Salmonella cell membrane cytoskeleton host cells

More articles from Life Sciences:

nachricht Scientists unlock ability to generate new sensory hair cells
22.02.2017 | Brigham and Women's Hospital

nachricht New insights into the information processing of motor neurons
22.02.2017 | Max Planck Florida Institute for Neuroscience

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

Microhotplates for a smart gas sensor

22.02.2017 | Power and Electrical Engineering

Scientists unlock ability to generate new sensory hair cells

22.02.2017 | Life Sciences

Prediction: More gas-giants will be found orbiting Sun-like stars

22.02.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>