Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How do we see bacteria

13.10.2004


Understanding how the body’s immune system recognises and responds to microorganisms can be a major step in the development of new therapies against infectious diseases. Towards this aim, a paper just released in the October issue of Embo reports1 discusses the process used by mammals to respond to bacteria such as Helicobacter pylori, Listeria monocytogenes and Streptococcus pneumoniae which are responsible for ulcers, Listeriosis and pneumonia, respectively.
In order to protect against infection it is necessary to detect invading microorganisms/ microbes capable of inducing disease. This is done through the recognition by the immune system of molecules unique to these invading organisms. In bacteria for example, components of their cell walls such as peptidoglycan, a polymer of sugars and peptides which is involved in cells shape and wall integrity, is one such target. The innate immune system is the first line of defence as it can be mobilised almost immediately and have a crucial role in prevention of infection. But the molecules/receptors and the mechanism involved in the recognition and clearance of microrganisms by this part of the immune system are still poorly known. Toll-like receptors (TLRs) are a family of molecules which have recently emerged as key components in the recognition of infectious agents by the innate immune system.

Now, Leonardo Travassos and Ivo G Boneca from the Institute Pasteur, Paris, France together with colleagues from the Federal University of the Rio de Janeiro, Rio de Janeiro, Brasil and the University Paris-Sud, in Orsay, France, found that TLR2, a member of the TRL family seems to recognise lipoteichoic acid (LTA) an important component of the bacteria cell wall, but does not recognize peptidoglycans, a result in clear disagreement with previous work by other groups. The differences found are due, according to Travassos, Boneca and colleagues, to contamination of the bacteria used in earlier research.


Before Travassos, Boneca and colleagues’ work it was believed that peptidoglycans were recognised through two different type of receptors; TRL2, which is present on the surface of cells of the immune system and by a family of molecules found in the intracellular space called nucleotide-binding oligomerization domain (NOD) a redundancy of roles that did not make much sense. What the team of scientists’ results show is that in fact the immune system uses these two recognition systems to target different molecules on the bacteria wall, the recognition mechanisms probably acting synergistically and so leading to a more powerful immune response and higher probability of getting rid of infection.

These are important results as detailed knowledge of the molecules and pathways involved in the control of the immune system during infection and inflammation opens the door to new highly selective therapeutics. Furthermore, the discovery that TRL2 seems to recognise LTA is extremely interesting as LTA only exists in the cell wall of Gram-positive bacteria (so called because they become positively coloured with Gram stain) and the initial steps of the innate immune response against this type of bacteria are still poorly understood. This is of great significance as Gram-positive bacteria are extremely important in clinical infections, for example, just in America, two Gram-positive bacteria -Pneumococcus and Staphylococcus - are responsible for almost 75% of all the antibiotic usage. Piece researched and written by Catarina Amorim catarina.amorim@linacre.ox.ac.uk

Catarina Amorim | alfa
Further information:
http://emboreports.npgjournals.com
http://www.oct.mct.pt

More articles from Life Sciences:

nachricht Scientists coax proteins to form synthetic structures with method that mimics nature
15.01.2019 | University of Texas at Austin

nachricht DNA library of apoid wasps published
15.01.2019 | Staatliche Naturwissenschaftliche Sammlungen Bayerns

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Nanocellulose for novel implants: Ears from the 3D-printer

Cellulose obtained from wood has amazing material properties. Empa researchers are now equipping the biodegradable material with additional functionalities to produce implants for cartilage diseases using 3D printing.

It all starts with an ear. Empa researcher Michael Hausmann removes the object shaped like a human ear from the 3D printer and explains:

Im Focus: Elucidating the Atomic Mechanism of Superlubricity

The phenomenon of so-called superlubricity is known, but so far the explanation at the atomic level has been missing: for example, how does extremely low friction occur in bearings? Researchers from the Fraunhofer Institutes IWM and IWS jointly deciphered a universal mechanism of superlubricity for certain diamond-like carbon layers in combination with organic lubricants. Based on this knowledge, it is now possible to formulate design rules for supra lubricating layer-lubricant combinations. The results are presented in an article in Nature Communications, volume 10.

One of the most important prerequisites for sustainable and environmentally friendly mobility is minimizing friction. Research and industry have been dedicated...

Im Focus: Mission completed – EU partners successfully test new technologies for space robots in Morocco

Just in time for Christmas, a Mars-analogue mission in Morocco, coordinated by the Robotics Innovation Center of the German Research Center for Artificial Intelligence (DFKI) as part of the SRC project FACILITATORS, has been successfully completed. SRC, the Strategic Research Cluster on Space Robotics Technologies, is a program of the European Union to support research and development in space technologies. From mid-November to mid-December 2018, a team of more than 30 scientists from 11 countries tested technologies for future exploration of Mars and Moon in the desert of the Maghreb state.

Close to the border with Algeria, the Erfoud region in Morocco – known to tourists for its impressive sand dunes – offered ideal conditions for the four-week...

Im Focus: Programming light on a chip

Research opens doors in photonic quantum information processing, optical signal processing and microwave photonics

Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a new integrated photonics platform that can...

Im Focus: Physicists uncover new competing state of matter in superconducting material

A team of experimentalists at the U.S. Department of Energy's Ames Laboratory and theoreticians at University of Alabama Birmingham discovered a remarkably long-lived new state of matter in an iron pnictide superconductor, which reveals a laser-induced formation of collective behaviors that compete with superconductivity.

"Superconductivity is a strange state of matter, in which the pairing of electrons makes them move faster," said Jigang Wang, Ames Laboratory physicist and...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

11th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Aachen, 3-4 April 2019

14.01.2019 | Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

 
Latest News

Scientists coax proteins to form synthetic structures with method that mimics nature

15.01.2019 | Life Sciences

Next generation photonic memory devices are light-written, ultrafast and energy efficient

15.01.2019 | Information Technology

Viennese scientists develop promising new type of polymers

15.01.2019 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>