Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists discover kill-switch controls immune-suppressing cells

15.07.2013
Scientists have uncovered the mechanism that controls whether cells that are able to suppress immune responses live or die.

The discovery of the cell death processes that determine the number of 'regulatory T cells' an individual has could one day lead to better treatments for immune disorders.

Regulatory T cells are members of a group of immune cells called T cells. Most T cells actively respond to clear the body of infections. By contrast, regulatory T cells are considered to be immune suppressing cells because they can 'switch off' an immune response to a particular molecule. This immune suppression is important for preventing inappropriate immune attack of the body's own tissues, which is the underlying cause of autoimmune diseases such as lupus and type 1 diabetes.

A shortage of regulatory T cells is linked with the development of autoimmune and inflammatory conditions, while some people with higher than normal numbers of regulatory T cells cannot fight infections properly.

Dr Daniel Gray and Ms Antonia Policheni from the Walter and Eliza Hall Institute's Molecular Genetics of Cancer and Immunology divisions made the discovery about how regulatory T cell numbers are controlled as part of an international team of researchers jointly led by Dr Gray and Dr Adrian Liston who is head of the Flanders Institute for Biotechnology (VIB) Laboratory for Autoimmune Genetics at the University of Leuven, Belgium. They found that regulatory T cells are constantly being produced in the body, but their numbers are held steady by a process of cell death. The findings are published today in the journal Nature Immunology.

Cell death, or apoptosis, is important in many immune cell types for the removal of excess, defective or damaged cells. The decision of these cells on whether to live or die is controlled by a family of proteins called the 'Bcl-2 protein family'. This includes proteins that can either promote cell survival or trigger cell death, in response to many different stimuli.

Dr Gray said the team had discovered that Bcl-2 family proteins were important determinants of regulatory T cell numbers. "Regulatory T cell death is highly dependent on the activity of two opposing Bcl-2 family proteins, called Mcl-1 and Bim," he said. "Mcl-1 is required for regulatory T cell survival, allowing them to suppress unhealthy immune responses, while Bim triggers the death of regulatory T cells. Without Mcl-1 activity, regulatory T cell numbers fall, provoking lethal autoimmune disease. Conversely, if Bim activity is lost, regulatory T cells accumulate in abnormally high numbers."

Dr Liston said the finding was exciting, because it opened up new ways to control regulatory T cell numbers in disease. "Already, there is considerable interest in a new class of agents, called 'BH-3 mimetics' that target Bcl-2-like molecules including Mcl-1," he said. "If agents that can influence regulatory T cell survival can be developed, we could see new ways to suppress autoimmune disease, by boosting regulatory T cell numbers, or to enhance beneficial immune responses, by silencing regulatory T cells."

The research was funded by the Australian National Health and Medical Research Council, the Victorian government, the European Union, the Belgian Government, and the VIB.

Liz Williams | EurekAlert!
Further information:
http://www.wehi.edu.au

More articles from Life Sciences:

nachricht World’s Largest Study on Allergic Rhinitis Reveals new Risk Genes
17.07.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Plant mothers talk to their embryos via the hormone auxin
17.07.2018 | Institute of Science and Technology Austria

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Microscopic trampoline may help create networks of quantum computers

17.07.2018 | Information Technology

In borophene, boundaries are no barrier

17.07.2018 | Materials Sciences

The role of Sodium for the Enhancement of Solar Cells

17.07.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>