Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Autoimmunity and Infections: When the Body Fights Itself

06.01.2017

Basel-based doctors are on the trail of a possible connection between autoimmune diseases and infections: errors can occur when immune cells absorb certain proteins from pathogen cells. These findings were reported in the journal PNAS by researchers from the Department of Biomedicine at the University of Basel and University Hospital Basel, as well as colleagues in the USA.

It is already known that there is a connection between infections and autoimmunity – the inability of an organism to recognize parts of its own body as “self”. As a result, increasing hygiene is leading to a higher incidence of autoimmune diseases in the population.

It is also apparent that some autoimmune diseases are triggered by infections. However, the mechanism behind these connections is still not fully understood. One possible explanation is that the immune system confuses protein structures from pathogens with the body’s own proteins because they look structurally alike.

Errors in protein uptake

Together with colleagues from the Whitehead Institute in Cambridge (USA), the Basel-based team of researchers tested out a new hypothesis in experiments to investigate the special ability of immune cells to identify specific proteins on the surface of neighboring cells and capture them from the cell membrane. In certain cases, errors can occur in the uptake of these proteins, as the group led by Professor Tobias Derfuss has now demonstrated.

Their assumption is that certain immune cells, so-called B cells, capture not only the protein of an influenza virus for which they were specialized, but also small quantities of other neighboring membrane proteins. One example of this is a protein known as an autoantigen that originates from the cell membrane layer in the central nervous system. An immune response to this membrane protein results in an autoimmune inflammation in the brain in the animal model and may well also contribute to inflammation of this kind in humans.

Harmful immune cells

B cells cultivated with cells that had incorporated both the influenza virus protein and the membrane protein were not only able to activate other immune cells, specifically certain T cells, in order to combat the virus; they also activated T cells that had recognized the body’s own membrane protein – which can trigger autoimmune inflammation in the brain. Consequently, a viral infection could lead to the activation of autoaggressive T cells through an error in the protein uptake of B cells.

The researchers discovered this mechanism after conducting experiments using cells from genetically modified mice. “The next step would now be to examine whether similar errors occur in protein uptake by human B cells. We also want to clarify whether a viral infection in an animal can, under certain circumstances, lead to autoimmune inflammation in the brain,” says Derfuss. Corresponding follow-up projects are planned.

Original paper
Nicholas S.R. Sanderson, Maria Zimmermann, Luca Eilinger, Céline Osswald, Nicole Schaeren-Wiemers, Raija L.P. Lindberg, Stephanie K. Dougan, Hidde Ploegh, Ludwig Kappos, and Tobias Derfuss
“Co-capture of cognate and bystander antigens can activate autoreactive B cells”
PNAS, Early Edition, January 5, 2017 | doi: 10.1073/pnas.1612062114

Further information
Professor Tobias Derfuss, Department of Biomedicine at the University of Basel and University Hospital Basel, Tel. ++41 61 328 67 26; Email: tobias.derfuss@usb.ch

Weitere Informationen:

http://www.pnas.org/content/early/2017/01/04/1614472114 - Abstract

lic. phil. Christoph Dieffenbacher | Universität Basel
Further information:
http://www.unibas.ch

More articles from Health and Medicine:

nachricht Unique brain 'fingerprint' can predict drug effectiveness
11.07.2018 | McGill University

nachricht Direct conversion of non-neuronal cells into nerve cells
03.07.2018 | Universitätsmedizin der Johannes Gutenberg-Universität Mainz

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: 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....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

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

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Research finds new molecular structures in boron-based nanoclusters

13.07.2018 | Materials Sciences

Algae Have Land Genes

13.07.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>