Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Flesh-eaters make skin creep

06.12.2001


Bacteria (red) persuade skin cells (green)to let them in.
© Nature


Bacteria give skin cells their marching orders.

Bacteria that cause potentially lethal ’flesh-eating’ infections make their entrance by telling skin cells to step aside. The bugs hijack the body’s signal for skin cells to become mobile.

Group A streptococci (GAS) normally infect the surface lining of the throat. But occasionally they penetrate skin or the tissues lining the airways, invading deep into the body and causing life-threatening disease.



Finding out how streptococci enter tissues doesn’t reveal why merely troublesome bacteria sometimes turn lethal. But it may lead to treatments for severe infections, called necrotizing fasciitis, and sore throats.

Michael Wessels and Colette Cywes at Harvard Medical School in Boston find that GAS are covered with a cloak of molecules that mimic a signal that is normally sent to mobilize cells1. "Cells don’t know any better - they think this is a signal to get up and move," says Wessels.

Like mortar being removed from a brick wall, the impenetrable layer of skin cells dissolves, allowing the bacteria in.

"This generates a new dogma," says Lukas Huber, a cell biologist at the Molecular Pathology Research Institute in Vienna, Austria. Invading bacteria normally infect and destroy individual cells. "Clearly [GAS] are much smarter than that," he says.

GAS’ deceitful cloak resembles a signalling chemical called hyaluronic acid. This is released when cells must be rearranged - to heal wounded skin, for example. "The bacteria subvert this normal function," says Wessels.

Hyaluronic acid - or its bacterial doppelganger - binds to a receptor on the cell surface called CD44. When this happens " the junctions [between the cells] just open," says Huber.

Wolf in sheep’s clothing

Wessels and Cywes infected laboratory cultures of human skin with GAS. They saw the skin-cell membranes ’ruffling’, a sign that they had let go of their neighbours. A mutant form of GAS unable to produce the deceptive molecular coat was unable to penetrate skin.

Wessels and Cywes are now working to prevent GAS infection by blocking the CD44 receptors on cells, or interfering with GAS binding. They hope to gain an understanding of why GAS turn nasty, although that may have more to do with the infected individual than the bacteria, Wessels suspects.

"There are host issues that play a big role in who’s going to get the disease," says Elaine Tuomanen, an infectious disease expert at St Jude’s Children’s Research Hospital in Memphis, Tennessee.

In the meantime, Wessel’s team hopes to develop a treatment to prevent throat infections with GAS.

"That’s certainly where the money is," comments Tuomanen.

References

  1. Cywes, C. & Wessels, M. R. Group A Streptococcus tissue invasion by CD44-mediated cell signalling. Nature, 414, 648 - 652, (2001).


TOM CLARKE | © Nature News Service
Further information:
http://www.nature.com/nsu/011206/011206-12.html

More articles from Life Sciences:

nachricht Transport of molecular motors into cilia
28.03.2017 | Aarhus University

nachricht Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Researchers shoot for success with simulations of laser pulse-material interactions

29.03.2017 | Materials Sciences

Igniting a solar flare in the corona with lower-atmosphere kindling

29.03.2017 | Physics and Astronomy

As sea level rises, much of Honolulu and Waikiki vulnerable to groundwater inundation

29.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>