What’s your research about?
'Fundamentally, we want to understand the principles of human coexistence with trillions of bacteria in our intestines. We as humans are deeply dependent on bacteria, the gut microbiota, for our health. Paradoxically, the same bacteria can turn into vicious enemies if they are not kept in check. Our way of controlling the microbiota is to establish various biological and physical barriers between our tissues and the bacteria. My lab studies the function of membrane mucins that cover the whole length of our small and large intestines. The first membrane mucins were described almost 50 years ago, but their function is still an enigma. We have recently shown that membrane mucins play an important role in protecting our intestinal cells against bacteria. Now, we are starting to realize that they play a much broader role in our coexistence with bacteria. For example, membrane mucins are also present in breast milk, where they present thousands of sugar molecules to the gut microbiota of the infant. These sugar molecules could help select beneficial bacteria or capture and eliminate harmful microbes.
How did you become interested in this topic?
'Rather late during my undergraduate studies in the Pharmaceutical Biosciences Program, I learned about mucins. Mucins are ancient and conserved proteins that emerged first in early vertebrates. But since they have complex genetics, and are very large and carry hundreds of sugar molecules, we have just started to understand their function. This huge knowledge gap was what drew me into research.
What's your scientific background?
'After my Master's degree, I got admitted to the PhD program at the Sahlgrenska Academy. My fascination for how biological processes occur at the molecular level led me to investigate how membrane proteins are transported within epithelial cells. Later during my postdoc at Cornell University, I had the opportunity to combine cell biology with enzyme chemistry to discover how proteins and membrane lipids cooperate to assemble finger-like protrusions (microvilli). These microvilli cover many types of epithelial cells and are vital for uptake and molecular exchange with the cells’ surroundings. Microvilli also provide structural support to membrane mucins. That was a lot of fun!
Who do you collaborate with?
'My lab is part of the Mucin Biology Groups (MBG). We are a research cluster of seven independent labs specializing on mucin biology at the interface between the microbiota and our immune system. MBG consist of nearly 30 researchers (postdocs, PhD students and undergrads), and we are probably the largest constellation of mucin researchers in the world. We are world-leading which is evident whenever you read the litterature. Naturally, there are a lot of nice collaborations taking place within MBG. Moreover, I have collaboration with Professor Magnus Simrén concerning the role of the bacterial pathogen Brachyspira in Irritable Bowel Syndrome (IBS). We believe that the pathogen has evolved to establish a very strong interaction with human mucins, which allows it to survive in the human colon, even after antibiotic treatment. I am also collaborating with Mikael Sellin, Uppsala University, on the kinetics of Salmonella infection in human intestine. And I am part of larger cluster of European researchers who study how the surface of epithelial cells, such as those in the intestine, are organized at a molecular level. These topic are very close to my heart, because I really love cell biology and I am very fascinated by the intricate molecular mechanism that rule cell morphology and function.
May, 2022
Interview by Niclas Lundh
More information can be found on Thaher Pelaseyed's research page at gu.se.
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