New research has updated our understanding of how sugars, known as glycans, help immune cells move into skin in the inflammatory disease, psoriasis.

The paper entitled “Leukocytes have a heparan sulfate glycocalyx that regulates recruitment during psoriasis-like skin inflammation” is published in the journal Science Signaling. The lead authors are Dr Amy Saunders from Lancaster University and Dr Douglas Dyer from the University of Manchester, with their joint PhD student, Dr Megan Priestley (now at MIT) as the first author.

Cells in our bodies, particularly those lining the blood vessel walls, are coated in a thick layer called the glycocalyx. This is a gel-like layer of complex sugars molecules on the outer surface of a cell membrane. The glycocalyx has many roles, including providing protection for the blood vessel wall from mechanical and chemical damage. More recently, the glycocalyx has been identified as playing in a role in controlling how immune cells move through our body.

Researchers identified that immune cells, which have their own cell surface glycocalyx, shed this layer to help them move from the blood and into tissues in inflammatory skin disease, changing the previous understanding that it was only the blood vessel wall that altered its glycocalyx layer to aid this process.

This glycocalyx shedding is an important response to inflammation, as it promotes immune cell movement from the blood into tissues, which is a crucial process in fighting infections. Immune cell recruitment can also be harmful for example, driving inflammatory diseases such as psoriasis, which affects skin.

Dr Saunders said: “It is really exciting to discover how important the glycocalyx layer is on immune cells, and I hope that this research will help to lay the foundations for future advances in inflammatory disease treatment.”

Dr Dyer said: “It has been a pleasure working collaboratively on this project to redefine our understanding of immune cell recruitment to try and better treat inflammatory disease.”

Dr Priestley said: “This was a really fun project to work on in my PhD, and I hope this research brings more attention to the importance of sugars in the immune system.”

Other members of the team included Dr Max Nobis at the University of Manchester (previously VIB-KU Leuven), and Professor Olga Zubkova of the Victoria University of Wellington in New Zealand.

Designing drugs to alter the movement of immune cells between the blood and tissues is a potential way to treat both infections and inflammatory diseases. Therefore, this research may alter the approach taken to develop drugs targeting the movement of immune cells into tissues.

The research was mainly funded by The Wellcome Trust and Royal Society.