Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Immune system molecule with hidden talents

22.01.2013
Fending off pathogens isn't all antibodies do - they also help to convey messages between immune cells

Dendritic cells, or DCs for short, perform a vital role for the immune system: They engulf pathogens, break them down into their component parts, and then display the pieces on their surface.


Dendritic cells, shown here in an electron microscopic picture, need antibodies produced by B cells for their maturation

HZI / Rohde

This in turn signals other immune cells capable of recognizing these pieces to help kick-start their own default program for fighting off the invaders. In order to do their job, the DCs are dependent upon the support from a class of immune system molecules, which have never before been associated with dendritic cells:

Antibodies, best known for their role in vaccinations and diagnostics. Now, scientists at the Helmholtz Centre for Infection Research (HZI) and the Hannover Medical School (MHH) were able to show that antibodies are essential for dendritic cell maturation. The researchers' findings have been published in the renowned scientific journal, Proceedings of the National Academy of Sciences (PNAS).

The human immune system is made up of some half a dozen different cell types that are all working in tandem. Team work is key since each cell type has a single unique job to perform, which is central to its ability to help defend the body against invaders and ward off disease. If one of these players is taken out of commission, the entire system is thrown out of whack.

This is precisely what Dr. Siegfried Weiss, head of HZI Department of Molecular Immunology, and his team of researchers observed when they looked at immunodeficient mice. "Our 'RAG' mice are lacking adaptive, or acquired immunity," explains Weiss. "Basically, what this means is they are missing their antibody-producing B cells, among others."

The dendritic cells belong to a different branch of the immune system - innate immunity, which, although far less pliable, is capable of a fairly rapid response. Which is why these cells should not be affected by a defect in acquired immunity. Still, the scientists noticed that DCs obtained from this particular murine strain were not working properly - their maturation process was faulty and instead of breaking down a pathogen into small pieces, they ended up destroying the pathogen altogether. "The broken down pieces are called antigens. Presenting antigen is the dendritic cells' main job," explains Dr. Natalia Zietara, one of the scientists who worked on this study. "In fact, it is one of the most important points of intersection between the immune system's innate and acquired branches. If it goes missing, any subsequent immune responses don't ever get triggered," adds her colleague, Dr. Marcin Lyszkiewicz. The cells' normally highly precise interplay comes to a standstill and the acquired immune response becomes largely ineffective at a targeted defense against invading pathogens.
Starting with this observation, the immunologists were interested in identifying the cause behind the defect in the DCs' function. To this end, they initially examined the dendritic cells' surface markers for any potential deviation from the norm - albeit to no avail. Only once they began studying the transcriptome, the sum total of genes that are active in the cells that were being examined, the researchers found what it was they were looking for: The activity of a select few genes, among them those encoding a family of receptors capable of binding antibodies, had been altered. Through a series of subsequent experiments, the researchers were able to show that it was these very molecules, which stimulated dendritic cell maturation.

Antibodies, also called immunoglobulins, are proteins made by B cells. Their normal job is one of neutralizing toxins or viruses and labeling bacteria for destruction by other immune cells. The concept of vaccination is based on artificially prompting the organism to make antibodies, which, at a later stage - specifically, upon contact with the actual pathogen - helps the body ward off disease. Until now, this new role for antibodies was completely unknown. "We had no idea that B cells and dendritic cells use immunoglobulins to communicate with each other. It just goes to show you how complex the immune system really is and how we are a long way from truly grasping the full scope of its complexity," says Dr. Andreas Krueger, head of the Lymphocyte Biology research group at the MHH's Institute of Immunology. In a way, you might say the researchers discovered a 'hidden talent' of antibodies.

Natalia Zietara and Marcin Lyszkiewicz are both named as the study's primary co-authors. They initially kicked off their investigation during the time of their doctoral work in Siegfried Weiss' department at HZI and, upon earning their PhDs, transferred to the MHH where they were able to see the project to its conclusion working in Andreas Krueger's lab. According to Weiss, "this is a prime example of a genuine scientific collaborative." Two other HZI research groups, along with scientists from Freiburg University and the Max Planck Institute of Immunobiology and Epigenetics, were also part of the research project.

Original publication:
Natalia Zietara, Marcin Lyszkiewicz, Jacek Puchalka, Gang Pei, Maximiliano Gabriel Gutierrez, Stefan Lienenklaus, Elias Hobeika, Michael Reth, Vitor A. P. Martins dos Santos, Andreas Krueger, Siegfried Weiss
Immunoglobulins drive terminal maturation of splenic dendritic cells
Proceedings of the National Academy of Sciences, 2013

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

The Lymphocyte Biology research group at the MHH's Cluster of Excellence REBIRTH and Institute of Immunology is working towards a better understanding of the fundamental processes underlying immune system development and using that understanding to develop strategies for returning the immune system to its original state of efficiency following a bone marrow transplant.

The Hannover Medical School (MHH) is one of Germany's most productive universities. Whether research, the provision of medical care, or teaching: through the focused support of individual key aspects, the MHH has claimed its stake among Germany's top university hospitals.

Joint release of HZI and MHH

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

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 >>>