Researchers from Freiburg and Ulm discover mechanism through which bacteria attack white blood cells
A research team led by Prof. Dr. Winfried Römer and Dr. Elias Hobeika from the University of Freiburg and the University Medical Center in Ulm has discovered a mechanism with which bacteria activate white blood cells and attack an organism’s immune system. The scientists recently published the results in the journal Science Signaling.
Source: Ella Levit-Zerdoun
The bacterial species Burkholderia ambifaria belongs to a group of bacterial strains that can cause infections in immunocompromised hosts. These bacteria produce so-called lectins, proteins that bind to carbohydrates. Among other things, lectin BambL is able to bind to the B-cell antigen receptor (BCR).
This protein is located on the surface of B cells, which belong to the white blood cells. The antigen receptor consists of a variable and a constant region that also carries several carbohydrate residues.
With its variable region, it specifically binds antigens, which also include pathogens. Inside the cell, it serves as a docking site for further molecules that trigger signaling processes in the immune cell. B cells are activated and mature into effector cells, the so-called plasma cells, which produce large amounts of antibodies against pathogens.
The researchers found out that lectin BambL binds to the carbohydrate residues of the antigen receptor in a controlled and artificial environment and thus activates the B cells: “We were surprised that a bacterial lectin initiates the strictly regulated antigen receptor signaling pathway,” says Dr. Isabel Wilhelm, a first author of the study. Prolonged stimulation with BambL led to the rapid death of the white blood cells. The process was only possible in cells with an intact antigen receptor.
The lectin injection into mice led to an immune response within three days, which showed increased amounts of B-cells in the spleen and their decrease in the bone marrow. Symptoms decreased in animals with fully functional immune systems within seven days. “However, there may be a risk for immunocompromised patients if they are unable to build up an effective response to pathogens,” says Dr. Ella Levit-Zerdoun, another lead author of the study.
Researchers from the BIOSS and CIBSS clusters of excellence in biological signaling research, the Spemann Graduate School of Biology and Medicine at the University of Freiburg, the Max Planck Institute of Immunobiology and Epigenetics and the University Medical Center in Ulm were involved in the work. The discovery of the mechanism provides the team with the opportunity for further investigations. The focus will be on the effects of the Burkholderia ambifaria pathogen on humans, possible preventive measures and treatment methods.
Wilhelm, I., Levit-Zerdoun, E., Jakob, J., Villringer, S., Frensch, M., Übelhart, R., Landi, A., Müller, P., Imberty, A., Thuenauer, R., Claudinon, J., Jumaa, H., Reth, M., Eibel, H., Hobeika, E. & Römer, W. (2019): Carbohydrate-dependent B cell activation by fucose-binding bacterial lectins. In: Science Signaling. DOI: 10.1126/scisignal.aao7194
Prof. Dr. Winfried Römer
Faculty of Biology, BIOSS and CIBSS
University of Freiburg
Dr. Elias Hobeika
Institute of Immunology
Ulm University Medical Center
Nicolas Scherger | idw - Informationsdienst Wissenschaft
Rising water temperatures could endanger the mating of many fish species
03.07.2020 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
Moss protein corrects genetic defects of other plants
03.07.2020 | Rheinische Friedrich-Wilhelms-Universität Bonn
Solar cells based on perovskite compounds could soon make electricity generation from sunlight even more efficient and cheaper. The laboratory efficiency of these perovskite solar cells already exceeds that of the well-known silicon solar cells. An international team led by Stefan Weber from the Max Planck Institute for Polymer Research (MPI-P) in Mainz has found microscopic structures in perovskite crystals that can guide the charge transport in the solar cell. Clever alignment of these "electron highways" could make perovskite solar cells even more powerful.
Solar cells convert sunlight into electricity. During this process, the electrons of the material inside the cell absorb the energy of the light....
Empa researchers have succeeded in applying aerogels to microelectronics: Aerogels based on cellulose nanofibers can effectively shield electromagnetic radiation over a wide frequency range – and they are unrivalled in terms of weight.
Electric motors and electronic devices generate electromagnetic fields that sometimes have to be shielded in order not to affect neighboring electronic...
A promising operating mode for the plasma of a future power plant has been developed at the ASDEX Upgrade fusion device at Max Planck Institute for Plasma...
Live event – July 1, 2020 - 11:00 to 11:45 (CET)
"Automation in Aerospace Industry @ Fraunhofer IFAM"
The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM l Stade is presenting its forward-looking R&D portfolio for the first time at...
With an X-ray experiment at the European Synchrotron ESRF in Grenoble (France), Empa researchers were able to demonstrate how well their real-time acoustic monitoring of laser weld seams works. With almost 90 percent reliability, they detected the formation of unwanted pores that impair the quality of weld seams. Thanks to a special evaluation method based on artificial intelligence (AI), the detection process is completed in just 70 milliseconds.
Laser welding is a process suitable for joining metals and thermoplastics. It has become particularly well established in highly automated production, for...
02.07.2020 | Event News
19.05.2020 | Event News
07.04.2020 | Event News
03.07.2020 | Life Sciences
03.07.2020 | Studies and Analyses
03.07.2020 | Power and Electrical Engineering