Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Overactive immune response blocks itself

26.07.2013
Too much of a good thing: In case of natural killer cells less is sometimes more

As part of the innate immune system natural killer cells (NK cells) play an important role in immune responses. For a long time they have been known as the first line of defense in the fight against infectious diseases.


When infected with Listeria monocytogenes (green) it is important to have the right immune cells present at the right time. Too many natural killer cells for example can block the recruitment of neutrophilic granulocytes (red) which are vital for the immune response.
© HZI / Jablonska

Therefore, researchers assumed that the body needs as many active NK cells as possible. However, scientists at the Helmholtz Centre for Infection Research (HZI) have now shown that the principle “the more the better” does not apply to this type of immune cells.

“During certain phases of the immune response it seems to be beneficial to have less active natural killer cells,” says Dr Jadwiga Jablonska-Koch, member of the research group “Molecular Immunology” at the HZI and responsible author of a new study published in the European Journal of Immunology. “This is particularly true during the beginning stages of an infection, which is precisely when they were assumed to be most important”.

Usually, Listeria monocytogenes infection leads to a deadly sepsis in mice and immune suppressed humans. Interestingly, researchers observed that removal of NK cells during the early stages of Listeria monocytogenes infection improves survival of the mice. These new findings could help to prevent sepsis in the future.

Until now it was believed that mice and humans die from listeriosis because their killer cells do not fight the infection effectively enough. However, the new results show the exact opposite. Even though the killer cells produce messenger substances that activate the immune system, the overproduction of the interferon IFN-ã causes problems. The large amounts of IFN-ã block the recruitment of neutrophilic granulocytes.

Those so-called scavenger cells are the most common white blood cells and are able to engulf bacteria and destroy them. If their migration to the site of infection is blocked in the initial phase, the bacteria can grow uncontrolled. This leads to fatal sepsis and death.

However, having no active NK cells could also lead to uninhibited bacteria proliferation. In later stages of an infection NK cells are crucial for the survival of both; mice and humans. “It is important to find the right balance for NK cell activity. It has to be high enough to activate other immune cells, but at the same time the migration and activation of scavenger cells shouldn’t be blocked,” says Jablonska-Koch.

Where exactly this balance lies is still not clear. At least, the scientists were able to show that in the later phases of infectious diseases it can be beneficial for the body to have large amounts of highly active NK cells. The discovery of HZI scientists could be relevant in the future, especially from a medical point of view. If these results prove to be true for humans and also for other bacteria, they could help to develop new treatment strategies. “If we know how exactly the killer cells function, we could use this information for treatment of bacterial infections. But it is still a long way to go,” says Jablonska-Koch.

Original Publication
Nuno Viegas, Lisa Andzinski, Ching-Fang Wu, Ronja-Melinda Komoll, Nelson Gekara,Kurt E. Dittmar, Siegfried Weiss, Jadwiga Jablonska
IFN-ã production by CD27+ NK cells exacerbates Listeria monocytogenes infection in mice by inhibiting granulocyte mobilization

European Journal of Immunology, 2013 DOI: 10.1002/eji.201242937

The focus of HZI's Department of Molecular Immunology is to investigate the role of signaling molecules used by the immune system. One of the primary research goals is to determine how immune cells communicate with each other during an infection and which messenger substances they use for this purpose.

The Helmholtz Centre for Infection Research:
At the Helmholtz Centre for Infection Research (HZI) in Braunschweig, scientists are studying microbial virulence factors, host-pathogen interactions and immunity. The goal is to develop strategies for the diagnosis, prevention and therapy of human infectious diseases.

http://www.helmholtz-hzi.de/en

Weitere Informationen:

http://dx.doi.org/10.1002/eji.201242937
- Link to the original publication
http://www.helmholtz-hzi.de/en/news_events/news/view/article/complete/
overactive_immune_response_blocks_itself/
- This press release on helmholtz-hzi.de

Dr. Jan Grabowski | Helmholtz-Zentrum
Further information:
http://www.helmholtz-hzi.de/en

More articles from Life Sciences:

nachricht Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY

nachricht NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

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....

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

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>