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 Study tracks inner workings of the brain with new biosensor
16.08.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht Foods of the future
15.08.2018 | Georg-August-Universität Göttingen

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: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Smallest transistor worldwide switches current with a single atom in solid electrolyte

17.08.2018 | Physics and Astronomy

Robots as Tools and Partners in Rehabilitation

17.08.2018 | Information Technology

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>