To bind or not to bind. A study into FcRn interactions

Thesis defense Nigel Stapleton

On  21 February 2020 (11:00) Nigel Stapleton will defend his thesis at the University of Amsterdam, Aula oude lutherse kerk. He studied FcRn interactions.

Immunoglobuline G (IgG) is one of the most important molecules in our immune system. It plays a pivotal role in protecting us from bacteria, viruses and cancers. IgG interacts with many receptors within the complex network that is our immune system to ensure that our immune responses are adequately used and controlled. Four distinct subclasses of IgG are found in humans, IgG1-4, each of which interacts with the immune system in its own unique way.

Long half-life

One receptor with which IgG interacts is FcRn, the neonatal Fc receptor. This interaction enables IgG to have its characteristic long serum half-life of 21-28 days, to be transported across tissue layers and to enhance IgG mediated phagocytosis. The long serum half life of IgG enables it to be the most abundant protein in our serum, which, considering the breadth required of our IgG repertoire to potentially bind any invading pathogen our body encounters, is important to our ability to mount an effective immune response rapidly when required.

The transport function allows IgG to be present where it is required, including in the circulation of newborn babies before they can produce their own IgG. And when a ligand is encountered, FcRn enhances our ability to phagocytose of invading microorganisms.

This thesis describes our research into the functioning of FcRn in the context of various IgG subclasses, endeavouring to add to the body of knowledge available about this unique receptor.

Promotor: prof. dr. C.E. van der Schoot
copromotor dr. G. Vidarsson