This is what regularly happens in the targeted immunological attack on the myelin sheaths of the nerve cells, as shown experimentally for the first time by researchers from Würzburg and Zürich.
Living tissue from the cerebral cortex of mice: Nerve cells are shown in green, their nuclei in blue. If you add T cells specialized in destroying myelin-generating cells, significant amounts of nerve cells also die off within six hours. They are displayed in red or yellow in the picture. The arrows point to the dead nerve cells. Picture: Heinz Wiendl
Inflammations in the central nervous system can be triggered by viruses or by the immune system. The latter is the case in multiple sclerosis. With drastic consequences: The cells responsible for building and maintaining an insulating sheath around the nerve fibers die off. The sheaths degenerate as well and often even the nerve cells are destroyed eventually.
"In the example of multiple sclerosis, not only the loss of the myelin sheaths but particularly the death of the nerve cells is thought to be decisive for the permanent disabilities that many patients have to deal with," says Professor Heinz Wiendl at the Department of Neurology of the University of Würzburg. Such disabilities include paralysis or impaired vision.
Now, for the first time, two study groups have simultaneously shown that certain T cells of the immune system not only directly affect the myelin-generating cells but also cause "collateral damage" to the nerve cells or their extensions. The research has been published in the journals Glia and American Journal of Pathology.
T cells: Indirect effect causes nerve cells to die
Wiendl's team at the Department of Neurology of the University of Würzburg was able to demonstrate this with brain tissue cultures: T cells exclusively targeting a specific structure on the surface of the myelin-generating cells also caused a significant loss of nerve cells within just a few hours. How this indirect effect might be accounted for is explained by Würzburg researcher Sven Meuth: "Possibly, the T cells release some soluble factors, such as perforin or granzyme B, which in turn migrate to and damage the nerve cells."
Serial murder: Each T cell strikes many times
The aggressive T cells act just like serial killers: "Every single one of them can kill off up to 30 myelin-generating cells and - at the same time - destroy up to ten nerve cells," says Heinz Wiendl.
These T cells virtually cut through the extensions of the nerve cells. This has been established by the team headed by Professor Norbert Goebels of the University of Zürich (now Düsseldorf) in a similar experimental approach by means of video analysis.
Possible target for new therapies
"These results help us to better understand the development of acute and chronic damage in inflammations of the central nervous system," explains Professor Wiendl. In future, the patients might also benefit from the findings - after all, the aggressive T cells are an attractive target for new therapies. Therefore, the Würzburg scientists are eager to find out as much as possible about these serial killers.
Multiple sclerosis: about the disease
Globally, approximately 2.5 million people are affected by multiple sclerosis; in Germany, there are about 122,000 patients according to current estimates. Here, approximately 2,500 new cases of the disease are diagnosed per year. Women aquire the disease almost twice as often as men.
In MS patients, the immune system mistakenly attacks the components of the nervous system, most prominently the nerve sheaths eventually destructing neural cells. Most often, the onset of the disease starts in early adulthood with relapsing remitting neurological symptoms. Initially people affected perceive tingling sensations in arms and legs, have walking disturbances or encounter visual problems. In the course of disease patients often acquire permanent disability. Some of them need a wheel-chair at later stages.
At the moment, there is no cure for multiple sclerosis; however, medical treatment can alleviate the symptoms of the patients and improve their quality of life. The Department of Neurology in Würzburg accommodates more than 2000 MS patients.
Prof. Dr. Heinz Wiendl, Department of Neurology of the University of Würzburg, T ++ 49 (931) 201-23755 or ++ 49 (931)201-23756, email@example.com
Prof. Dr. Norbert Goebels, Department of Neurology of the University of Düsseldorf, firstname.lastname@example.org
"Collateral neuronal apoptosis in CNS gray matter during an oligodendrocyte-directed CD8(+) T cell attack", Göbel K, Melzer N, Herrmann AM, Schuhmann MK, Bittner S, Ip CW, Hünig T, Meuth SG, Wiendl H, Glia 2009, online publiziert am 24. September
"Collateral bystander damage by myelin-directed CD8+ T cells causes axonal loss", Sobottka B, Harrer MD, Ziegler U, Fischer K, Wiendl H, Hünig T, Becher B, Goebels N, American Journal of Pathology 2009; 175(3):1160-6, online publiziert am 21. August
"CD8+ T cells and neuronal damage: direct and collateral mechanisms of cytotoxicity and impaired electrical excitability", Melzer N, Meuth SG, Wiendl H, FASEB Journal 2009, online publiziert am 30. Juni
Robert Emmerich | idw
Atomic-level motion may drive bacteria's ability to evade immune system defenses
24.04.2017 | Indiana University
Two-dimensional melting of hard spheres experimentally unravelled after 60 years
24.04.2017 | University of Oxford
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
24.04.2017 | Physics and Astronomy
24.04.2017 | Materials Sciences
24.04.2017 | Life Sciences