Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Reins and Spurs for the Immune System

16.08.2006
How Disruptions of T Cell Balance Induce Severe Intestinal Inflammation
A finely tuned equilibrium between aggressive and inhibitive immune cells ensures that the intestinal mucosa remains healthy and functional.

Scientists at the Helmholtz Centre for Infection Research in Braunschweig, however, have studied on mice what happens when the normal interaction between these cells is disrupted: severe intestinal inflammation, whose symptoms closely resemble human autoimmune diseases, such as Morbus Crohn or Colitis ulcerosa.

"The intestinal surfaces form a border between the insides of the human body and the outside world, and they present our immune system with a monumental task," explains Dr. Astrid Westendorf, a researcher at the Helmholtz center. "Bacteria and other disease-causing pathogens that attempt to penetrate the body must be vehemently repelled at this point," she says. "On the other hand, nutrients, as well as the body's own cells and molecules, must not induce an immune reaction. Otherwise, a severe inflammation could result which might, in the long term, cause serious damage, and in some cases, even destroy the intestinal mucosa."

Dramatic Symptoms

This is exactly what happens with so-called Villin HA-mice, which were studied by Westendorf and her colleagues. "These animals belong to a genetically altered strain that possess a molecule known as hemagglutinin, or HA, on the cells of their intestinal mucosa," she says. Westendorf injected these animals with immune cells from the blood of other mice strains that specifically produced immune cells targeting HA. The result: the immune cells attacked the intestinal surface and induced dramatic symptoms similar to those of patients with chronic intestinal inflammation.

A Surprising Tolerance

When these two strains of mice are cross-bred, however, they produce something astonishing: "The progeny have both the HA on the intestinal surface as well as the special immune cells against HA in their blood, and yet, they remain healthy," notes Westendorf. The reason for this phenomenon, known as "immune tolerance", is probably the so-called regulatory T cells, or TREG , which are specific inhibitors of the immune system that shut down other defense cells before they go too far with their attacks and cause harm to the body. "These TREG must have developed in the animals in the course of their lives," says Dr.

Westendorf. They keep the defense cells in check, most of which are the CD4+ or CD8+ type T cells, since these would otherwise attack the always present components of their own intestinal surface.

Complex Interaction

"The constant interaction between aggressive T cells and inhibiting TREG keeps the immunological balance of our intestinal mucosa intact," explains Prof. Dr. Jan Buer, work group leader at the Helmholtz Centre for Infection Research. "Many chronic, inflammatory intestinal ailments occur because this balance no longer functions," he says. Buer hopes that a better understanding of the processes involved could open up opportunities to selectively turn immune system responses up or down. "That," he says, "could lead to possible therapies for autoimmune diseases, like Morbus Crohn, but also tumors and infections in which the immune reaction needs to be selectively activated."

Manfred Braun | alfa
Further information:
http://www.gbf.de

More articles from Health and Medicine:

nachricht One gene closer to regenerative therapy for muscular disorders
01.06.2017 | Cincinnati Children's Hospital Medical Center

nachricht The gut microbiota plays a key role in treatment with classic diabetes medication
01.06.2017 | University of Gothenburg

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>