ABSTRACT
Breast milk is generally accepted as the perfect source of nutrition for the health and development of infants. It also assists in infant innate and adaptive immunity through many proteins that are decorated with glycans. Examples of these glycoproteins include IgA, IgG, and innate immune lectins. Maternal diet and environmental exposure such as pathogens and pollutants affect human milk composition including its glycoprofile. Despite altered glycosylation can have a consequence on the nursing infant's health and immunity, the current knowledge is still emerging in this area of study. COVID-19 has gained attention in recent years by causing severe morbidity and mortality. Similar to other infectious diseases such as influenza, our lab recently revealed alterations in glycome of plasma and different tissue samples of COVID-19 infected patients. Inspired by these findings, we are interested in disclosing the effect of SARS-CoV-2 on glycosylation of breast milk proteins. Toward this, we performed a large-scale systematic study using our high-throughput lectin microarray analysis technology. We analyzed 132 control samples (breast milk collected pre- COVID) and breast milk from 78 COVID-19 infected mothers. Our data showed there is a 4-fold increase in -2,3 sialic acid on glycoproteins that is associated with SARS-CoV-2 infection in lactating mothers. Lectin pulldown experiments further testified to these findings. Given the significance of -2,3 sialic acid glycan signature in infectious diseases, our finding could provide valuable insight into therapeutic development.Copyright © 2023 The American Society for Biochemistry and Molecular Biology, Inc.