Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Stroke: When Helper Cells Become Harmful

16.11.2012
In case of strokes, the immune system contributes to the brain injury. In the prestigious journal BLOOD, scientists of the Universities of Würzburg and Münster now show for the first time in which way certain T helper cells are involved in the process.

The course of a stroke was previously described by scientists as follows: A blood vessel supplying the brain with oxygen and vital nutrients is suddenly blocked by a blood clot. This leads to a stroke, causing injury to the brain. As a result, many patients suffer from neurological dysfunctions, such as severe paralysis or speech disorders.


After a stroke, regulatory T cells (green) can be mainly identified in the cerebral vessels (red), where they interact with the vessel wall, clotting the respective blood vessel in the process (upper row of pictures). Accordingly, the cerebral blood flow (lower row of pictures) after a stroke is significantly higher in mice without regulatory T cells (right) than in normal mice (left). For measuring the cerebral blood flow, the animals were examined in an MRI scanner.
Picture: Christoph Kleinschnitz / Heinz Wiendl

"This picture must be supplemented by another important factor, namely the immune system," says Professor Christoph Kleinschnitz, head of stroke medicine at the University of Würzburg's Department of Neurology. He verified this in a joint project with the study group of Professor Heinz Wiendl at the University Hospital of Münster.

Regulatory T cells as culprits

The new insight was discovered in mice the immune system of which lacks regulatory T cells due to a genetic defect: The brain damage sustained by these mice after a stroke is reduced by about 75 percent as compared to normal mice. Furthermore, these mice develop significantly fewer neurological dysfunctions.

Regulatory T helper cells are an important part of the immune system and usually have the task of suppressing excessive immune responses of the body. Due to their regulatory properties, they play a protective role in many diseases, such as multiple sclerosis or rheumatism.

Paradigm shift in immunology

"The fact that regulatory T cells aggravate the brain damage to this extent in acute stroke cases came as a complete surprise to us," reports Heinz Wiendl, Director of the Department of Neurology, Division for Inflammatory Diseases of the Nervous System and Neuro-Oncology at the University Hospital of Münster: "We can say without exaggeration that this constitutes a paradigm shift from the perspective of immunology."

In their research, the immunologists also investigated with which mechanisms the regulatory T cells exacerbate the harmful effect of a stroke. They found out that this cell type interacts with platelets and blood vessel walls, especially in the early stages after a stroke. This worsens the clotting of the cerebral vessels, further reducing the cerebral blood flow.

The next studies

The scientists are now going to determine whether the results can be applied to humans. Should this be the case, strokes might be treated in future with drugs that affect regulatory T cells.

"This would represent a small medical revolution," says Kleinschnitz, for stroke is a widespread disease, having become the second leading cause of death worldwide. Effective therapies are scarce. "It will still take a series of further studies, however, to translate the discovery into an effective drug treatment," Kleinschnitz emphasizes.

Sponsors of the research

The studies were funded by the German Research Foundation (DFG) and by the Else Kröner-Fresenius Foundation. The DFG supported the research via the excellence cluster "Cells in motion" in Münster and the collaborative research center 688 in Würzburg.

"Regulatory T cells are strong promoters of acute ischemic stroke in mice by inducing dysfunction of the cerebral microvasculature", Christoph Kleinschnitz, Peter Kraft, Angela Dreykluft, Ina Hagedorn, Kerstin Göbel, Michael K Schuhmann, Friederike Langhauser, Xavier Helluy, Tobias Schwarz, Stefan Bittner, Christian T Mayer, Marc Brede, Csanad Varallyay, Mirko Pham, Martin Bendszus, Peter Jakob, Tim Magnus, Sven G Meuth, Yoichiro Iwakura, Alma Zernecke, Tim Sparwasser, Bernhard Nieswandt, Guido Stoll, Heinz Wiendl. Blood, published ahead of print November 15, 2012, doi:10.1182/blood-2012-04-426734

Contact persons

Prof. Dr. Christoph Kleinschnitz, Department of Neurology at the University Hospital of Würzburg, T (0931) 201-23756, christoph.kleinschnitz@uni-wuerzburg.de

or Prof. Dr. Heinz Wiendl, Department of Neurology – Division for Inflammatory Diseases of the Nervous System and Neuro-Oncology, University Hospital of Münster, T (0251) 83-46810, heinz.wiendl@ukmuenster.de

Robert Emmerich | Uni Würzburg
Further information:
http://www.ukmuenster.de

More articles from Health and Medicine:

nachricht Study suggests possible new target for treating and preventing Alzheimer's
02.12.2016 | Oregon Health & Science University

nachricht The first analysis of Ewing's sarcoma methyloma opens doors to new treatments
01.12.2016 | IDIBELL-Bellvitge Biomedical Research Institute

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: 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...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

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

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>