Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Immune peacekeepers discovered

18.10.2011
How our skin says, 'Don't worry, these are good guys,' revealed today in PNAS

Sydney: Tuesday 18 October 2011 -- There are more bacteria living on our skin and in our gut than cells in our body. We need them. But until now no-one knew how the immune system could tell that these bacteria are harmless.

Centenary Institute researchers in Sydney have discovered a set of peacekeepers—immune cells in the outer layers of our skin that stop us from attacking friendly bacteria.

The work will open the way to new therapeutic options for immune-mediated diseases such as inflammatory bowel disease, of which Australia has some of the world's highest rates.

In a paper published today in the Proceedings of the National Academy of Sciences (PNAS), Professor Barbara Fazekas de St Groth and her team have shown that the immune cells in the outer layer of the skin constantly act as peacekeepers to stop the immune system from reacting the way it normally would. Known as Langerhans cells, they resisted every attempt by the researchers to get them to generate an immune response.

The researchers worked with a group of mice in which only the Langerhans cells could stimulate the immune system. They then activated the Langerhans cells and measured the response.

"No matter what we threw at them to get them to activate a long-term immune response, the Langerhans cells always induced immune tolerance," Prof Fazekas says.

This result seems to go against the prevailing wisdom in immunology about the workings of dendritic cells, the class of immune cell to which Langerhans cells belong.

Dendritic cells engulf bacteria, viruses or other invaders and put a marker from that invader, known as an antigen, on a protein that can bind to other immune cells.

The antigen reprograms passing T cells, the workhorses of the immune system, which then set off a cascade of responses that eventually lead to the destruction of anything displaying that antigen.

However, the Centenary team (which is affiliated with the University of Sydney and RPA Hospital) found Langerhans cells are very different from other dendritic cells: after turning on the helper T cells, they tell them to self-destruct instead.

"This is the opposite of what you'd usually expect. In previous studies of immune cells, if there was a flurry of activity, we assumed it was the start of a long-term immune response," Prof Fazekas says.

However, the immune system is a layered defence¬—the next layer of skin has different kinds of dendritic cells, which program on-going responses against bacteria. So if bacteria penetrate deep enough to meet these cells, the immune response will kill them.

In inflammatory bowel disease, which afflicts thousands of Australians, the immune system is activated against the gut bacteria, which are usually left alone.

This discovery opens up possible ways to figure out why this disorder occurs and to find treatments to a range of diseases of the immune system.

"There is so much we don't know about the immune system, but sometimes just mimicking what the system does, like we do with vaccines, can work very well" Prof Fazekas says,

"If we do manage to mimic what Langerhans cells do, then we could develop treatments that would precisely tolerise against specific antigens – just like the immune system of the skin does now."

Centenary Institute executive director Professor Mathew Vadas says this latest paper comes just weeks after Centenary researcher Patrick Bertolino made the front cover of PNAS for his paper on immune response in the liver.

"The Centenary Institute is interested in understanding how the immune system works—these discoveries and others already in the pipeline here are a major step forward towards that goal," Prof Vadas says.

For interviews contact: Barbara Fazekas de St Groth:+61 2 9565 6137

For hi-res images, backgrounder, paper and full release go to: http://www.scienceinpublic.com.au/centenary or call Andrew Wight on (03) 9398 1416, +61 422 982.

Suzie Graham | EurekAlert!
Further information:
http://www.centenary.org.au

More articles from Life Sciences:

nachricht New photocatalyst speeds up the conversion of carbon dioxide into chemical resources
29.05.2017 | DGIST (Daegu Gyeongbuk Institute of Science and Technology)

nachricht Copper hydroxide nanoparticles provide protection against toxic oxygen radicals in cigarette smoke
29.05.2017 | 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: Strathclyde-led research develops world's highest gain high-power laser amplifier

The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.

The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

New insights into the ancestors of all complex life

29.05.2017 | Earth Sciences

New photocatalyst speeds up the conversion of carbon dioxide into chemical resources

29.05.2017 | Life Sciences

NASA's SDO sees partial eclipse in space

29.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>