Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Fine-tuning for intestinal immune cells

17.05.2016

An international team of researchers under the leadership of the LIMES Institute and the excellence cluster ImmunoSensation of the University of Bonn unraveled a new regulatory mechanism how food components and environmental factors influence the immune system. Various substances present in the intestines can bind to an important controller, the Ah receptor. This system is in turn regulated by the Ah receptor repressor and as a result, it influences the degree of the immune response. If the controller is not properly adjusted during bacterial infections, there can be life-threatening septic shock, for example. The results are now being published in the journal “Scientific Reports".

The intestines’ primary role is digestion but they must also achieve high performance around the clock defending against pathogens and environmental pollutants. This is because everything taken up with food ultimately ends up in the digestive tract.


Decoded the mode of operation of an important controller for immune response: Jessica Koenig, Dr. Julia Vorac, associate professor Dr. Heike Weighardt, Prof. Dr. Irmgard Foerster and Oliver Schanz.

© Photo: Volker Lannert/University of Bonn

“The intestines assume an important barrier function so that, to the greatest extent possible, no harmful organisms and substances are able to overcome this bastion,” says Prof. Dr. Irmgard Foerster, who is researching the connection between immunology and the environment at the Life and Medical Sciences (LIMES) Institute and in the excellence cluster ImmunoSensation of the University of Bonn.

The immune system in the intestines must be continually rebalanced. If its response is weak, pathogens and noxious substances have an easy job. If the immune reaction is excessive, there can be harmful inflammation – for example, colitis – to the point of life-threatening septic shock.

The “Ah receptor” (aryl hydrocarbon receptor) plays an important role in this fine-tuning of the immune system in the intestines. A receptor is a protein onto which certain molecules latch – similarly to how a key fits into a lock. A large variety of substances can bind to the Ah receptor and thus trigger certain signal chains: aromatic hydrocarbons as they develop, for example, through the breakdown of food components, but also environmental toxins such as dioxins.

Ah receptor and its repressor control the immune response together

The Ah receptor has a counterpart: the Ah receptor repressor which partially inhibits the effect of the Ah receptor. “Together, both ensure that there is an appropriate immune response,” says Dr. Heike Weighardt from Prof. Foerster’s team. Up to now, it was largely unknown how the Ah receptor repressor worked.

Together with scientists from the IUF Leibniz Research Institute for Environmental Medicine in Duesseldorf and the Waseda University in Tokyo (Japan), the researchers at the LIMES Institute and the excellence cluster ImmunoSensation of the University of Bonn have now researched how the interaction of the Ah receptor and its repressor works.

Using a mouse model, the team of scientists replaced the gene for the Ah receptor repressor with one for a protein which fluoresces green. “Whenever the gene for the Ah receptor repressor is to actually become active, the fluorescing protein glows,” says Oliver Schanz from the University of Bonn, one of the lead authors of the study.

It was demonstrated that the repressor in the intestinal immune cells is always particularly active when the Ah receptor is also operating at full speed. “Our data show that for a balanced immune response, both counterparts are necessary,” says Prof. Foerster.

The Ah receptor repressor increases the risk of septic shock

If the immune system mounts an excessive response, this can result in impending life-threatening septic shock through cardiovascular failure and organ damage. The team of researchers mutated the gene in mice for the Ah receptor repressor and the animals were then protected from such a hazardous shock.

By contrast, a malfunction of the Ah receptor repressor as well as of the Ah receptor itself led to increased sensitivity for chronic bowel inflammation. Both antagonists affect the production of immunostimulating substances, which include, for example, interleukin-1 beta or interferon gamma. “There is an appropriate immune response only if the Ah receptor and the Ah receptor repressor are in balance,” Dr. Weighardt concludes from these findings.

According to the scientists, the study shows that food can have a significant influence on the immune system. When vegetables – such as broccoli, for example – contain many substances which bind to the Ah receptor and thus activate the associated repressor, this may stabilize the immune system in the intestines. “The degree to which the results investigated in a model approach in animals can be transferred to humans must still be researched further,” says Prof. Foerster.

Publication: Balancing intestinal and systemic inflammation through cell type-specific expression of the aryl hydrocarbon receptor repressor, Scientific Reports, DOI: 10.1038/srep26091

Media contact information:

Prof. Dr. Irmgard Foerster
Immunology and Environment
LIMES Institute
ImmunoSensation Excellence Cluster
University of Bonn
Tel. ++49-(0)228-7362780 or 7362789
E-Mail: irmgard.foerster@uni-bonn.de

Johannes Seiler | idw - Informationsdienst Wissenschaft
Further information:
http://www.uni-bonn.de

More articles from Life Sciences:

nachricht What happens in the cell nucleus after fertilization
06.12.2016 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Researchers uncover protein-based “cancer signature”
05.12.2016 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Simple processing technique could cut cost of organic PV and wearable electronics

06.12.2016 | Materials Sciences

3-D printed kidney phantoms aid nuclear medicine dosing calibration

06.12.2016 | Medical Engineering

Robot on demand: Mobile machining of aircraft components with high precision

06.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>