SARS-CoV-2 adherance is primarily mediated by sialylated glycans with α-(2,6)-sialic acids: Human milk oligosaccharides can block RBD

A group from Department of Chemistry, University of California, Davis, Davis, CA, USA, etc. has reported that the binding of SARS-CoV-2 to the cell membrane is primarily mediated by sialylated glycans with α-(2,6)-sialic acids on the termini positions.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8964299/

It was tested whether the Human milk oligosaccharides (HMOs) could block the RBD of SARS-CoV-2 by preincubating the RBD and the HMOs before introduction to HepG2 cells. Fluorescently labelled RBD was preincubated with 2′-FL, LNnT and 6′-SL separately, then allowed to interact with host cells HepG2. Quantitation of fluorescent signal intensity showed that HMOs blocked binding of RBD to cells presumably reflecting the behavior of the intact virus. The RBD was blocked only slightly by 2′FL (not statistically significant), more by LNnT (significant), and the most by 6′SL . Comparison of LNnT and 6′SL showed that latter one is more effective (significant).

The data suggest that HMOs can potentially function as “decoys” to affect SARS-CoV-2 adherence.