Prof. Thomas Gramberg – Fuel for reproduction
Discovery of mechanism that enables herpes viruses to access cellular building blocks
Around 60 to 90 percent of all adults carry the human cytomegalovirus, or human betaherpesvirus 5. In healthy people, an infection with the virus usually has very few or no symptoms. However, the virus can have serious complications for pregnant women, newborn babies and people whose immune system is suppressed by medication. Teams of researchers at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) and Universitätsklinikum Tübingen have now discovered how the virus’ genome manages to reproduce in human cells and why it is not stopped by the body’s immune system. They have now published their results in two studies in the renowned journal ‘Nature Microbiology’.
Viruses such as the human cytomegalovirus (CMV) can only reproduce in the body if they have a constant supply of nucleotides, the building blocks of DNA. In the cell, an enzyme called SAMHD1 ensures that it contains enough, but not too many nucleotides. In this way, the cell defends itself from pathogens, allowing the DNA to replicate and be repaired without errors, which in turn, prevents tumours from forming.
During an infection with CMV, however, the virus entering the cells blocks the enzyme, which means that nucleotides are continuously produced in the cell and the virus can replicate freely. The mechanism was investigated by working groups led by Janina Deutschmann, a doctoral candidate at the Professorship for Antiviral Native Immunity of Prof. Dr. Thomas Gramberg (FAU), and Dr. Ramona Businger at the laboratory of Prof. Dr. Michael Schindler (Tübingen) on cells from humans and mice. The results not only form an important basis for new treatments for CMV infections. The researchers hope that their work will take them a step further in the fight against tumours as well as other acute viral infections. Previous studies have shown that not only other viruses but presumably also tumours also have to block the SAMHD1 enzyme in order to replicate effectively.
Prof. Dr. Thomas Gramberg