Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A glimpse into the nanoworld of lymphocyte cell membranes

16.09.2015

University of Freiburg researchers have applied super-resolution methods to study the organization of receptors on B lymphocytes

Antigen receptors on B lymphocytes sense foreign molecules, such as pathogens or vaccines, and activate the B cells to produce antibodies that protect humans against many diseases. Prof. Dr. Michael Reth, Scientific Director of BIOSS Centre for Biological Signalling Studies, and his group have applied three different super-resolution methods to study the distribution of the two major classes of antigen receptors on mature B lymphocytes:


Researchers previously assumed that receptors such as the antigen receptors of class Immunoglobulin M (IgM) and Immunoglobulin D (IgD) are freely diffusing and equally distributed molecules on the membrane (image above). However, the new study shows that these antigen receptors are organized in different membrane compartments, also called "protein islands", with diameters of 150-200 nanometers (image below). This finding is another indication that, at nanoscale distance, the proteins on cellular membranes are highly organized. Credit: Research Group Reth

Immunoglobulin M (IgM) and Immunoglobulin D (IgD). It had been previously assumed that all proteins on the membrane, including receptors, are freely diffusing molecules that only become organized upon binding to specific ligands. Reth’s group found out that IgM and IgD receptors are organized in protein islands.

The researchers from the University of Freiburg collaborated with Prof. Dr. Hassan Jumaa from the University of Ulm/Germany and Prof. Dr. Björn F. Lillemeier from the Salk Institute in La Jolla/USA. The imaging analysis was conducted in collaboration with Dr. Olaf Ronneberger’s group, computer scientist at the University of Freiburg.

The team has published their research findings in the journal Science Signaling. The researchers hope that these new insights into the nanoscale organization of antigen receptors will support the design of more efficient vaccines or better treatments for B cell tumors where membrane organization is often altered.

Using two-color direct stochastical optical reconstruction microscopy (dSTORM), the researchers found that IgM and IgD reside on the plasma membrane of resting B cells in separated protein islands of approximately 150 and 240 nanometers (nm), respectively.

This class-specific compartmentalization of the antigen receptors is also detected by transmission electron microscopy (TEM) and Fab-based proximity-ligation assay (Fab-PLA) studies. Upon B cell activation, the IgM and IgD protein islands became smaller and the two classes of receptors are now found in close proximity to each other.

These studies provide direct evidence for the nanoscale compartmentalization of the lymphocyte membrane. Furthermore, they suggest that upon B cell activation, the different IgM and IgD protein islands form nano-synapses which allow the exchange of lipids and proteins. This could explain how the IgM class antigen receptors find contact to Raft-associated lipids and proteins. The association of IgM with these lipids is a well-known hallmark of B cell activation.

Michael Reth is professor of molecular immunology at the Institute of Biology III at the University of Freiburg and speaker of the Cluster of Excellence BIOSS Centre for Biological Signalling Studies. Palash Maity, lead author of the study, is a postdoc at BIOSS and at the Max Planck Institute of Immunobiology and Epigenetics in Freiburg.

Olaf Ronneberger is working at the Institute of Computer Science. Ronneberger and Hassan Jumaa are both members of BIOSS Centre for Biological Signalling Studies. This study is part of the BIOSS nanoscale explorer program (BiNEP), which is a focus topic in the BIOSS-2 research program. In this program, BIOSS is developing methods to better understand the nanoworld of signaling processes, beyond the 250 nm diffraction limit of visible light.

Original publication:
Palash Chandra Maity, Amy Blount, Hassan Jumaa, Olaf Ronneberger, Björn F. Lillemeier and Michael Reth (2015). B cell antigen receptors of the IgM and IgD classes are clustered in different protein islands that are altered during B cell activation. Science Signaling 8, Issue 394. DOI: 10.1126/scisignal.2005887

Contact:
Prof. Dr. Michael Reth
Institute of Biology III and BIOSS Centre for Biological Signalling Studies
University of Freiburg
Phone: +49 (0)761 / 203 - 97663
E-Mail: michael.reth@bioss.uni-freiburg.de

Weitere Informationen:

http://www.pr.uni-freiburg.de/pm/2015/pm.2015-09-16.128-en

Rudolf-Werner Dreier | idw - Informationsdienst Wissenschaft

More articles from Life Sciences:

nachricht A novel socio-ecological approach helps identifying suitable wolf habitats
17.02.2017 | Universität Zürich

nachricht New, ultra-flexible probes form reliable, scar-free integration with the brain
16.02.2017 | University of Texas at Austin

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Biocompatible 3-D tracking system has potential to improve robot-assisted surgery

17.02.2017 | Medical Engineering

Real-time MRI analysis powered by supercomputers

17.02.2017 | Medical Engineering

Antibiotic effective against drug-resistant bacteria in pediatric skin infections

17.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>