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 Not of Divided Mind
19.01.2017 | Hertie-Institut für klinische Hirnforschung (HIH)

nachricht CRISPR meets single-cell sequencing in new screening method
19.01.2017 | CeMM Forschungszentrum für Molekulare Medizin der Österreichischen Akademie der Wissenschaften

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland

19.01.2017 | Earth Sciences

Not of Divided Mind

19.01.2017 | Life Sciences

Molecule flash mob

19.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>