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 Norovirus evades immune system by hiding out in rare gut cells
12.10.2017 | University of Pennsylvania School of Medicine

nachricht Flexible sensors can detect movement in GI tract
11.10.2017 | Massachusetts Institute of Technology

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: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Ocean atmosphere rife with microbes

17.10.2017 | Life Sciences

Neutrons observe vitamin B6-dependent enzyme activity useful for drug development

17.10.2017 | Life Sciences

NASA finds newly formed tropical storm lan over open waters

17.10.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>