Glycans can teach us a lot about infections and vaccines

Scientific publishing. Research into sugar chains known as glycans could provide an increased understanding of viral infections and pave the way for new types of vaccines. This is the opinion of virology researchers in Gothenburg, who wrote a general article on the topic.

Much of the work that forms the basis of the overall article in the Annual Review of Virology has been carried out here, at Virologien in Gothenburg. Glycan research has a long history at the University of Gothenburg, and today has led to a widespread impact on biomedical research at the university.

First contact

Almost all viruses use sugar structures called glycans as their first contact with the cells they are going to infect. Glycans are found on the cell surface and on the envelope of many viruses, including the viruses that cause Covid, influenza and herpes. However, common cold viruses are not surrounded by such a membrane sac.

The virus steals its membrane from infected cells. The proteins in the virus envelope then bind to new cells and also ensure that the virus can enter the cell, says Sigvard Olofsson.

Sigvard Olofsson is a former assistant professor at the University of Gothenburg. In his 1980 thesis, he made fundamental contributions to the field of glycan research by comprehensively mapping their role in herpes infection.

sustainable interest

There are two different types of glycans, both of which are involved in the infection process.

N-glycans, which are attached to the protein via nitrogen, enable the infection of new cells. These glycans were actually discovered in the 1960s and have been well explored.

O-glycans, attached to proteins with oxygen bonds, are important for virus replication. Regarding these glycans, there is still much to discover, which may increase understanding of viral infections and potentially lead to new types of vaccines, the researchers note in their review article.

We see that there is continuing interest in studies on the role of O-glycans in infection. Works generate low frequency of citations, but they persist long after publications, says Thomas Bergstrom, a senior professor of clinical microbiology.

Great complexity

There is great diversity among glycans. They were created under seemingly chaotic conditions, making it difficult to create a good overview.

– In human cells there are more than a hundred different genes that code for each enzyme, which then compete with each other and can also cooperate to assemble glycans. This provides diversity that cannot be read from the genetic code, but the formation of glycans depends on how the enzymes are used and how they are controlled, says Siegvard Olofsson sympathetically.

– The sugar structure varies greatly, and this large variation may be a disadvantage for enveloped viruses. But no matter what it looks like on the cell, there always seems to be some virus that has the right constellation on its surface to be able to find its way into the cell and infect it, believes Thomas Bergström.

The Gothenburg virologists are also co-authors of a new paper in Nature Communications, which presents a library of skin cells where individual glycans could be affected. This library could serve as an important tool in ongoing research on the function of glycans at different stages of herpes infection.

long history

Glycans have a broad meaning to how cells function – from receptors on the cell surface to determining the function of proteins. These sugar structures therefore remain of great interest to basic researchers in a range of medical fields, from infections to cancer.

There is also a long tradition of research on glycans at the University of Gothenburg, which actually began in the 1960s. Biochemists and professors Stina and Einar Steinhagen then developed new methods for the structural analysis of glycans and lipids using gas chromatography and mass spectrometry. These methods have been used by researchers in various fields, and have been important for many groups that today conduct successful carbohydrate-related research on Medicinareberget. One example of this is mucin biology, where the work of Professor Gunnar C. Hansson has paved the way for many successful research groups.

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Written by: Ellen Lindstrom