‘Sugar coating on our cells may hold key to better vaccines, immunity’

To a layman, glycobiology may not make much sense. But what if we told you that each of our cells comes coated in sugar. And that some influenza viruses affect the upper airways and some infect deeper lungs because of their altered interaction with the kind and volume of sugar. This information is crucial to not only vaccine development but developing the right immunity-boosting diet.

Glycobiology is the study of the structure, biosynthesis and biology of glycans (carbohydrates). Can you decode it in simple terms?

Glycobiology, simply put, is the study of sugar in living systems. Sugar levels serve critical functions and there is not a single, free living cell that does not cover its surface with sugar. For instance, some influenza viruses affect the upper airways and some infect deeper lungs because of altered interaction with sugars. While it is likely that the heavily sugar-coated spike protein of SARS CoV2 will also have similar properties, it is inadequately studied. There has not been much active research in the country in the field of glycobiology, which has the potential to provide insights into immunology, virology, reproductive biology and drug development.

The proposed center for glycobiology at Ashoka University will study glycans that can provide deeper biological understanding and help predict and treat complex diseases. It can scientifically evaluate Indian traditional knowledge systems and beliefs about Indian foods.

What aspects can scientists explore?

At the core of health and many diseases is glycobiology — the role that 20 different simple sugars (mono-saccharides) and their complex combinations with proteins and lipids (glycans) plays in our physiology. The effort is to begin with establishing core capacity in glycan synthesis and measurement and extend to investigating Indian traditional knowledge systems for dietary wellness and susceptibility to diseases. For example, scientists can explore how cells and pathogens use glycans in immunity. Other experts can explore linkages of such insights with advice that is given for traditional diets, with special reference to the bacteria in our gut that digest the type of complex sugars these traditional diets contain.

Study applications of glycobiology can enhance food-based wellness, combating antibiotic resistance and targeting metastatic spread of triple negative breast cancer among other areas.

Can you give us an example?

Often questions are asked about what could be a healthy diet for an Indian from a scientific point of view and why particular foods should be consumed in specific ways. Unlike proteins and fats, many complex sugars can only be broken down after fermentation by environmental and gut bacteria. With 20 different kinds of simple sugar in the body — each sugar can bind another in five different ways — and further binding to amino acids, proteins and lipids, the combinations are too many for human enzymes.

For instance, there was an outbreak of severe gastrointestinal symptoms in a hospital that cooked red beans (rajma) without soaking them sufficiently. It turned out that those beans contained a lectin, glycan, which overactivated the immune system. Soaking is essential for bacteria to digest that glycan and change the nutritional value. We are trying to build such conversations across natural and social sciences and addressing difficult problems by answering biologically important questions that can have a wider societal impact. The final effect of most things we eat depends on our gut bacteria and food is digested by us and them. Even identical twins may react very differently to foods because of variation in gut microbiology/microbiome.

What is the role of glycobiology in making better vaccines?

During the pandemic, there has been a lot of conversation and discussion on different kinds of food to promote natural immunity. There is no simple yes or no to such suggestions but studies of these hidden aspects may offer insights. Research has found that every single cell found in nature is completely covered with sugar, even COVID spike proteins are covered with complex sugar. More combinations of such sugars binding with each other are also a possibility. Even antibodies bind with sugars (and not just with proteins) that are present on the cell surface. For example, Gp130 (Gp stands for glycoproteins). Many successful vaccines are targeted at glycans, not simple proteins alone. It will be important to look into how cells make and change the sugar on their surface to evade immunity.

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