Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Investigating the immune system

07.01.2013
Immune cells undergo complex processes during their development. If errors occur, the consequences for those who are affected can be fatal. Scientists from the University of Würzburg have now uncovered new details of what happens. These could be a target for new therapies.
As recently as a few decades ago, the following response was feared: following an organ transplant, the patient’s immune system recognizes the transplanted organ as “foreign” and therefore attacks and rejects it. It was not until the discovery, nearly 30 years ago, that the mycotoxin cyclosporin A can prevent the rejection of a transplanted organ that this response lost its capacity to terrify.

“In T cells, which are important cells in the immune system, cyclosporin A inhibits the activation of a group of transcription factors called NFAT factors,” explains Professor Edgar Serfling, a researcher at the University of Würzburg’s Institute of Pathology. At the time, this finding was tantamount to a “revolution in transplantation medicine”. “Thousands of patients owe their lives to cyclosporin A and the inhibition of NFAT factors,” says Serfling.

Now Serfling, his Research Associate Amiya K. Patra, and other scientists at the University of Würzburg have uncovered new details of the interaction between transcription factors and immune cells. Their work has just been published online in the journal Nature Immunology.

The development of T cells

To enable T cells to recognize transplanted organs or pathogenic viruses and bacteria as foreign material, they first have to be “educated”. This education takes place in the thymus – hence the name T cells. There, the immigrant progenitor cells of the cells later known as thymocytes are subjected to various selection processes in which NFAT factors also play an important role. “If errors occur in these processes, this often leads to autoimmune diseases, such as multiple sclerosis, psoriasis, and rheumatism,” explains Serfling. In multiple sclerosis, for example, autoreactive T cells in the brain attack the myelin sheaths of nerve cells, causing the fatal symptoms of this disease.

In the thymus, thymocyte progenitors develop special receptors on their surface where the body’s own transmitter interleukin 7 (IL-7) can dock. After it has docked, IL-7 transmits signals that activate or deactivate numerous genes in the cells. The progenitor cells subsequently divide and evolve into mature thymocytes.
New insights into the development process

As Amiya Patra has now revealed, NFAT factors also play a significant part in these processes: “If a specific NFAT factor is deactivated in mice, the thymocytes remain in their earliest stage of development and no thymus is created,” explains Serfling. However, if the early steps of thymocyte development that are controlled by IL-7 proceed without disruption, the cell soon forms other receptors that are important to its development and the IL-7 receptor disappears.

Though it is not just the absence of the NFAT factor that disrupts cell development; an excess also messes up the process: the development of thymocytes stops, but at a later stage in this case, and again with fatal consequences: “Specific progenitor receptors are created in an uncontrolled manner, with the result that the person affected develops leukemia, and NFAT factors play a critical role in this too,” explains Serfling.

Approach for new therapies

Through their work the Würzburg team has demonstrated that NFAT factors are critically involved not only in the recognition of the body’s own tissue and in immune responses, but also in the “education” of T cells in the thymus. They therefore represent a target structure that will play a key role in therapies for autoimmune diseases and leukemia in the future.

“An alternative NFAT-activation pathway mediated by IL-7 is critical for early thymocyte development”. Amiya K Patra, Andris Avots, René P Zahedi, Thomas Schüler, Albert Sickmann, Ursula Bommhardt & Edgar Serfling; Nature Immunology, doi:10.1038/ni.2507

Contact

Prof. Dr. Edgar Serfling, T: +49 (0)931 31-81207,
e-mail: serfling.e@mail.uni-wuerzburg.de

Robert Emmerich | idw
Further information:
http://www.uni-wuerzburg.de

More articles from Life Sciences:

nachricht About injured hearts that grow back - Heart regeneration mechanism in zebrafish revealed
10.02.2016 | Universität Ulm

nachricht Chemical cages: New technique advances synthetic biology
10.02.2016 | Arizona State University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: The most accurate optical single-ion clock worldwide

Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock which attains an accuracy which had only been predicted theoretically so far. Their optical ytterbium clock achieved a relative systematic measurement uncertainty of 3 E-18. The results have been published in the current issue of the scientific journal "Physical Review Letters".

Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock...

Im Focus: Goodbye ground control: autonomous nanosatellites

The University of Würzburg has two new space projects in the pipeline which are concerned with the observation of planets and autonomous fault correction aboard satellites. The German Federal Ministry of Economic Affairs and Energy funds the projects with around 1.6 million euros.

Detecting tornadoes that sweep across Mars. Discovering meteors that fall to Earth. Investigating strange lightning that flashes from Earth's atmosphere into...

Im Focus: Flow phenomena on solid surfaces: Physicists highlight key role played by boundary layer velocity

Physicists from Saarland University and the ESPCI in Paris have shown how liquids on solid surfaces can be made to slide over the surface a bit like a bobsleigh on ice. The key is to apply a coating at the boundary between the liquid and the surface that induces the liquid to slip. This results in an increase in the average flow velocity of the liquid and its throughput. This was demonstrated by studying the behaviour of droplets on surfaces with different coatings as they evolved into the equilibrium state. The results could prove useful in optimizing industrial processes, such as the extrusion of plastics.

The study has been published in the respected academic journal PNAS (Proceedings of the National Academy of Sciences of the United States of America).

Im Focus: New study: How stable is the West Antarctic Ice Sheet?

Exceeding critical temperature limits in the Southern Ocean may cause the collapse of ice sheets and a sharp rise in sea levels

A future warming of the Southern Ocean caused by rising greenhouse gas concentrations in the atmosphere may severely disrupt the stability of the West...

Im Focus: Superconductivity: footballs with no resistance

Indications of light-induced lossless electricity transmission in fullerenes contribute to the search for superconducting materials for practical applications.

Superconductors have long been confined to niche applications, due to the fact that the highest temperature at which even the best of these materials becomes...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Travel grants available: Meet the world’s most proficient mathematicians and computer scientists

09.02.2016 | Event News

AKL’16: Experience Laser Technology Live in Europe´s Largest Laser Application Center!

02.02.2016 | Event News

From intelligent knee braces to anti-theft backpacks

26.01.2016 | Event News

 
Latest News

About injured hearts that grow back - Heart regeneration mechanism in zebrafish revealed

10.02.2016 | Life Sciences

The most accurate optical single-ion clock worldwide

10.02.2016 | Earth Sciences

Absorbing acoustics with soundless spirals

10.02.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>