A new study by the group of Professor Sebastian Springer at Jacobs University helps explain how viruses manage to go undetected when they infect body cells. They have shown that the gp40 protein of the murine cytomegalovirus (mCMV) binds to cellular proteins that are essential for the antiviral immune defense and holds them back inside the cell. This blocks the immune response against mCMV.
Major histocompatibility complex (MHC) class I molecules play a pivotal role in the immune defense against intracellular parasites, such as viruses. Inside the cell, they selectively bind small pieces of the virus that are generated during infection and transport them to the cell surface to display the infection to the immune system, a process called antigen presentation.
Specialized immune cells, the cytotoxic T lymphocytes (CTL), can recognize those viral pieces and, in turn, kill the infected cell in order to fight the infection (see left part of figure).
It is not astonishing that many viruses aim to interfere with antigen presentation by MHC class I molecules to circumvent elimination. Herpesviruses are masters of immunoevasion and possess a series of multiple interfering proteins, the immunoevasins:
The gp40 protein of mCMV inhibits the transport of MHC class I molecules to the cell surface and thus viral recognition by CTL. Instead, MHC class I molecules are retained inside the cell (see right part of figure).
"We have shown for the first time that gp40 binds to MHC class I molecules", says Professor Springer. "We do not yet know how gp40 itself is kept inside the cell, but we believe that it uses another protein as some sort of anchor." The researchers identified a region in the gp40 protein, the linker, which probably binds to this unknown cellular retention factor (see right part of figure).
"It is an amazingly effective strategy for a virus to escape from the immune response", concludes Professor Springer. "Cytomegaloviruses and other herpesviruses infect humans and animals and cause many diseases. We need to understand more about immune escape so that effective treatments can be designed."
The findings will soon be published in the “Journal of Cell Science”. Linda Janßen, Venkat Raman Ramnarayan, Mohamed Aboelmagd, Maria Iliopoulou, Zeynep Hein, Irina Majoul, Susanne Fritzsche, Anne Halenius, and Sebastian Springer: “The murine cytomegalovirus immunoevasin gp40 binds MHC class I molecules to retain them in the early secretory pathway”, Journal of Cell Science, 2015. The study was financed in part by the Tönjes Vagt Foundation of Bremen.
Sebastian Springer | Professor of Biochemistry and Cell Biology
firstname.lastname@example.org | Tel.: +49 421 200- 3243
About Jacobs University:
Jacobs University is a private, independent, English-language university in Bremen. Young people from all over the world study there on Bachelor’s, Master’s and PhD courses. Jacobs University is international and trans-discipline: research and teaching do not pursue one single pathway, but instead approach issues from the viewpoints of different disciplines. This is what makes Jacobs’ graduates highly sought-after for employment in successful international careers.
Kristina Logemann | idw - Informationsdienst Wissenschaft
Nesting aids make agricultural fields attractive for bees
20.07.2017 | Julius-Maximilians-Universität Würzburg
The Kitchen Sponge – Breeding Ground for Germs
20.07.2017 | Hochschule Furtwangen
Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...
What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.
To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...
The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....
A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...
Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision
Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...
19.07.2017 | Event News
12.07.2017 | Event News
12.07.2017 | Event News
20.07.2017 | Information Technology
20.07.2017 | Materials Sciences
20.07.2017 | Physics and Astronomy