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Wistar Science Synergy Through Fostering International Collaborations 

Inaugural graduate students from Leiden University Medical Center speak to their Wistar experience.

The Wistar-Schoemaker International Postdoctoral Fellowship is a special exchange of postdoctoral fellows between our two institutes. We sat down with Katarina Madunić and Tamas Pongracz to hear more about this important science interchange and what is next in their research careers

What is your scientific expertise and how is it connected to Wistar?

Katarina Madunić: My mentor Dr. Manfred Wuhrer got to know Dr. Mohamed Abdel-Mohsen during a collaborative seminar that we organized together with Wistar and LUMC to exchange current research results. We learned very early on that we have mutual interests and might benefit from each other’s expertise. Dr. Abdel-Mohsen’s work is focused on various aspects of HIV biology and glycoimmunology. My Ph.D. was in cancer research where I studied glycosylation of colorectal cancer – specifically a largely unexplored type of glycosylation called mucin type O-glycosylation.

In my research at Leiden University Medical Center (LUMC), I discovered that sugar molecules attached to proteins (glycans) are specifically expressed by tumors, yet never appear in normal tissue of the patient. This makes glycans promising targets for antibody-based immunotherapy. At LUMC, our focus is on structural glycomics where we explore which glycans are expressed in different tissues and cells in different diseases. This is complementary to Dr. Abdel-Mohsen’s lab, which has more of a focus on the role of different glycans in the immune system, and in diseases like HIV.

In HIV infection, there is an interplay between gut tissue, its glycosylation, and microbiota. Translocation of the microbiota during HIV infection causes long term inflammation leading to health complications. The key question this work is trying to answer is whether glycosylation of the gut cells is linked to the diversity of the microbiota and their translocation during HIV infection. At Wistar, I am exposed to different techniques such as lectin array and mass spectrometry to analyze gut glycosylation. My expertise is in mass spectrometry, so when I observed the data, I brought a different perspective to its interpretation.

Tamas Pongracz: Our antibodies – crucial in the fight against the SARS-CoV-2 virus – are coated with sugars in a process called glycosylation. Part of my Ph.D. research focused on antibody glycosylation signatures in COVID-19 infection. Using mass spectrometry, I identified these antibody-linked sugars and found specific coating patterns that are associated with disease severity at hospitalization. Based on these patterns, we could predict how a patient’s disease would progress. The study took place within the framework of a multi-disciplinary collaboration at LUMC, turning the pandemic into a scientifically fruitful period. This is a complementary time to be at Wistar and observing the research taking place Mohamed Abdel Mohsen’s lab. Interestingly, sugars can modify their inflammatory potential depending on how antibodies are coated —Mohamed’s lab specializes in this topic. During my time, I got to see how specific sugars affect antibody function

We are so grateful to be here and supported through this Fellowship that brings researchers from Leiden to Wistar to nurture new scientific collaborations. While we are here, the visit also has a diplomatic flavor because we are the first visitors from Leiden. We are pioneering the collaboration between the two labs.

What are some next steps for you both – scientifically and professionally?

KM: I accepted a postdoctoral fellowship in Copenhagen, Denmark on the team of Dr. Adnan Halim. There, my work will be more focused on understanding what specific function glycans have on a particular protein.  My long-term plan is to come back to the Netherlands after the postdoctoral fellowship. Colon glycosylation and it’s interplay with the gut microbiota in the context of different inflammatory diseases as well as cancer is a subject that sparks my interest the most, and I would like to continue working on this subject in the future.

TP: Once we are back at Leiden, both of us will spread the news about how great Wistar is and that international collaboration is key for both institutes. I feel very much attached to glycobiology. In the future, I would like to be part of an interdisciplinary team studying the mechanistic aspects of glycosylation, a field currently gaining more and more attention.

Anything to add about your experience?

KM: Dr. Abdel-Mohsen and members of his lab welcomed us very warmly here. Samson, Ferlina, and Shalini gave us a thorough understanding of the assays they utilize. They also organized a lab night out where we went bowling and got to know each other better.

TP: Leadership has welcomed us so warmly. We dined with Anne Schoemaker—her late husband Hubert is who this Fellowship has been named after, and we heard how supportive and brilliant he was as a scientist and how human he was. That was touching, and we are very privileged to be supported by this Program. I think that this has been a great kickstart of the collaboration. We already have ideas on what to explore when we return home and it’s going to be fruitful for everyone.