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 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

NASA eyes Pineapple Express soaking California

24.02.2017 | Earth Sciences

New gene for atrazine resistance identified in waterhemp

24.02.2017 | Agricultural and Forestry Science

New Mechanisms of Gene Inactivation may prevent Aging and Cancer

24.02.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>