Gestur Vidarsson has been appointed professor of Immunoglobulin Biotherapeutics

Sanquin has a new professor: Gestur Vidarsson. He has been appointed professor of Immunoglobulin Biotherapeutics at Utrecht University, department of Pharmaceutical Sciences. One of his specializations is the crucial role of sugars in certain antibodies.

Antibodies, or immunoglobulins, are the proteins our blood makes to fight off germs. With their arms, they can cling to invaders, which results in their elimination. "Antibodies normally recognize anything foreign to the body," says Vidarsson. "There role is to stop bacteria and viruses, for instance."


But sometimes the body reacts too strongly due to an overactive immune response, making patients critically ill, as is the case in serious COVID-19. Vidarsson's goal is to understand how this overreaction occurs and in what type of patients. "In our work, we focus on the most common type of antibodies, Immunoglobulin G, or IgG. We want to recognize the characteristics of the antibodies that occur in high-risk groups of patients with diagnostic tests, enabling evidence-based treatment options. At the same time, Vidarsson wants to deploy his research for therapeutic purposes in other areas. For example, the pharmaceutical industry produces IgG antibodies as anti-inflammatory drugs for autoimmune diseases such as rheumatoid arthritis, or to kill tumor cells in certain types of cancer. By modulating the sugar composition of those antibodies we can better tailor immune responses."

Fucose determines the strength of immune responses

It turns out that the strength of the immune response does not always depend on the amount of antibodies a person makes, but mainly on the composition of the antibody. A crucial role is reserved for a - seemingly - simple component: the sugar fucose. Vidarsson: "In most immune reactions fucose is built into the antibodies, but sometimes it is lacking. This depends on the invader, but also on the individual. When fucose is lacking, this results in a stronger immune response."

Blood Groups

Vidarsson's research originates in the investigation into blood groups at Sanquin. About 15 years ago, Vidarsson and his colleagues discovered that antibodies lacking fucose play an important role in rhesus disease, when a rhesus negative woman is pregnant of a rhesus positive baby. "This overly strong type of defense breaks down the child's red blood cells, which is highly undesirable and even life-threatening for the (unborn) baby. And yet it has persisted throughout evolution," says Vidarsson. "The reason for that is probably that it does play an important role in combating dangerous infectious diseases. My group recently discovered that fucose is lacking in the antibodies our bodies make against malaria: to effectively fight that parasite - often multiple times - the human body needs that fierce immune response." 

According to Vidarsson, this knowledge can also be used in booster vaccines and against cancer cells. "If you take the fucose out of antibodies developed to kill cancer cells, then you can get a stronger effect." In the spring of 2020, Vidarsson and his colleagues also investigated the immune response of COVID-19. "There, too, fucose plays a role. People who build less fucose into their antibodies can become seriously ill from corona as a result of their strong immune response."


Gestur Vidarsson will combine his work at Sanquin with one day a week at Utrecht University. "Part of my lab activities will also take place in Utrecht. It's great that we can combine our specific knowledge. Together, we will be able to speed up our research." In addition to research, Vidarsson will also teach at the university. "I think it is important that we also involve the current and future generation of students in our work, to share our knowledge about the multifaceted world of antibodies."