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 Hopkins researchers ID neurotransmitter that helps cancers progress
25.04.2019 | Johns Hopkins Medicine

nachricht Trigger region found for absence epileptic seizures
25.04.2019 | RIKEN

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Full speed ahead for SmartEEs at Automotive Interiors Expo 2019

Flexible, organic and printed electronics conquer everyday life. The forecasts for growth promise increasing markets and opportunities for the industry. In Europe, top institutions and companies are engaged in research and further development of these technologies for tomorrow's markets and applications. However, access by SMEs is difficult. The European project SmartEEs - Smart Emerging Electronics Servicing works on the establishment of a European innovation network, which supports both the access to competences as well as the support of the enterprises with the assumption of innovations and the progress up to the commercialization.

It surrounds us and almost unconsciously accompanies us through everyday life - printed electronics. It starts with smart labels or RFID tags in clothing, we...

Im Focus: Energy-saving new LED phosphor

The human eye is particularly sensitive to green, but less sensitive to blue and red. Chemists led by Hubert Huppertz at the University of Innsbruck have now developed a new red phosphor whose light is well perceived by the eye. This increases the light yield of white LEDs by around one sixth, which can significantly improve the energy efficiency of lighting systems.

Light emitting diodes or LEDs are only able to produce light of a certain colour. However, white light can be created using different colour mixing processes.

Im Focus: Quantum gas turns supersolid

Researchers led by Francesca Ferlaino from the University of Innsbruck and the Austrian Academy of Sciences report in Physical Review X on the observation of supersolid behavior in dipolar quantum gases of erbium and dysprosium. In the dysprosium gas these properties are unprecedentedly long-lived. This sets the stage for future investigations into the nature of this exotic phase of matter.

Supersolidity is a paradoxical state where the matter is both crystallized and superfluid. Predicted 50 years ago, such a counter-intuitive phase, featuring...

Im Focus: Explosion on Jupiter-sized star 10 times more powerful than ever seen on our sun

A stellar flare 10 times more powerful than anything seen on our sun has burst from an ultracool star almost the same size as Jupiter

  • Coolest and smallest star to produce a superflare found
  • Star is a tenth of the radius of our Sun
  • Researchers led by University of Warwick could only see...

Im Focus: Quantum simulation more stable than expected

A localization phenomenon boosts the accuracy of solving quantum many-body problems with quantum computers which are otherwise challenging for conventional computers. This brings such digital quantum simulation within reach on quantum devices available today.

Quantum computers promise to solve certain computational problems exponentially faster than any classical machine. “A particularly promising application is the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

Fraunhofer FHR at the IEEE Radar Conference 2019 in Boston, USA

09.04.2019 | Event News

 
Latest News

High-efficiency thermoelectric materials: New insights into tin selenide

25.04.2019 | Materials Sciences

Salish seafloor mapping identifies earthquake and tsunami risks

25.04.2019 | Earth Sciences

Using DNA templates to harness the sun's energy

25.04.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>