Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Choice between two evils

13.06.2012
Multiple sclerosis continues to puzzle scientists in all sorts of ways. Now researchers from the University of Würzburg have managed to make some progress in the search for the causes of this disease. They have revealed that in order to avoid greater damage the brain accepts a lesser evil.

The “disease with 1000 faces” is how multiple sclerosis (MS) is sometimes described. The reason for this name is that the clinical picture can differ dramatically from patient to patient – in terms of both the progression of the disease and the symptoms suffered.

However, there is one finding that is the same in principle for everyone: multiple sclerosis is an autoimmune disease where one particular type of brain cell, known as an oligodendrocyte, is destroyed by the immune system. Oligodendrocytes form an insulating layer around the extensions of nerve cells that is required for efficient impulse conduction.

If this conduction is disturbed as a consequence of damage to the insulating layer, the nerves cannot transfer relevant “messages” as effectively as before. This is why multiple sclerosis sufferers often feel a tingling sensation in their extremities. Patients stumble more or have difficulties seeing. In extreme cases, they become incapable of moving around on their own and are confined to a wheelchair. According to the Multiple Sclerosis Society of Germany, around 2.5 million people worldwide have MS. The latest projections indicate that some 130,000 sufferers live in Germany; around 2,500 people are diagnosed with the disease each year.

Killer T cells are suspected of being a cause

The full details of what triggers the onset of the disease are not yet known. “Based on tests done on the brains of deceased MS patients, it has long been suspected that a certain type of lymphocyte, the killer T cell, is involved in destroying oligodendrocytes,” says Professor Thomas Hünig from the Institute of Virology and Immunobiology at the University of Würzburg. Together with scientists from Cologne and Dresden, Hünig and his colleague, Dr. Shin-Young Na, have now taken a closer look at this process and have made a surprising discovery. This is reported in the latest issue of the journal Immunity. They found that the brain itself allows the T cells to attack the myelin sheath under specific conditions – because by doing so it may be able to prevent greater damage to the sufferer.

Even though the findings from the brains of deceased MS patients point to a strong involvement by killer T cells, scientists have always had a problem with this: “In animal experiments, which are unavoidable for the development of new treatment strategies, there has been no convincing demonstration of an attack on the nerve sheaths that is mediated by killer T cells,” explains Hünig. For this reason, the research group made their search a little more complicated.

They infected mice in the laboratory with a specific species of bacteria – listeria –, which shares a protein with oligodendrocytes, and observed the consequences when peripheral parts of the body were infected and when the infection was confined to the brain.

The brain decides

The outcome: “With an infection in the periphery, the killer cells search for the pathogen all over the body, including the brain,” says Hünig. However, in this case the immune system is able to identify those killer cells that mistake the myelin sheaths for something alien because they recognize the protein the sheaths share with listeria and so attack. It fights the killer cells and destroys them. It is a different story when the infection is in the brain itself: “Then the attack is allowed, which destroys the protective myelin sheath and leads to the formation of the plaques you see with multiple sclerosis,” explains the scientist.

A kind of “trade-off” seems to be responsible for the difference in progression. The brain’s “decision” to allow the attack helps combat the pathogen. It would appear that the brain is applying the motto: better that a few infected cells are destroyed and nerve cell extensions are demyelized than that the pathogen spreads and may therefore kill the sufferer. However, in the absence of an infection with menacing pathogens, the brain “recognizes” that this is a misguided attack by killer T cells and destroys them. It is possible, though, that the brain may sometimes “overestimate” the threat posed by a microbial pathogen and may sacrifice the protective myelin sheath unnecessarily.

Next steps

“These findings could form the basis for future therapies focused on combating microbial pathogens in the brain as well as reducing the local inflammation they cause,” hopes Hünig. Since many researchers are convinced that viruses can trigger certain forms of multiple sclerosis, he believes it makes sense to continue to conduct research in this direction.

Oligodendrocytes Enforce Immune Tolerance of the Uninfected Brain by Purging the Peripheral Repertoire of Autoreactive CD8+ T Cells; Shin-Young Na, Andreas Hermann, Monica Sanchez-Ruiz, Alexander Storch, Martina Deckert and Thomas Hünig; Immunity, Published online: June 7, DOI: 10.1016/j.immuni.2012.04.009

Contact
Prof. Dr. Thomas Hünig, Department of Immunology, T: +49 (0)931 201-49951, e-mail: huenig@vim.uni-wuerzburg.de

Gunnar Bartsch | idw
Further information:
http://www.uni-wuerzburg.de

Further reports about: T cells immune system immunity killer T cells multiple sclerosis nerve cell

More articles from Health and Medicine:

nachricht Satellites, airport visibility readings shed light on troops' exposure to air pollution
09.12.2016 | Veterans Affairs Research Communications

nachricht Oxygen can wake up dormant bacteria for antibiotic attacks
08.12.2016 | Penn State

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: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

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...

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

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>