Cell-surface glycans act as attachment factors for porcine hemagglutinating encephalomyelitis virus

Porcine hemagglutinating encephalomyelitis virus (PHEV) is a neurotropic coronavirus and highly pathogenic in veterinary clinic. Spike (S) protein of PHEV interplays with host components to cross the plasma membrane of target cells, but characterization of its functional receptors is limited. Here, we discovered that cell-surface glycans, i.e., sialic acid (SA) and heparan sulfate (HS), act as critical interacting factors of PHEV, involving in viral attachment. As shown in glycans depletion assay, removing SA or HS from N2a cells inhibits PHEV infection. Soluble sugar monomers were utilized for competitive binding tests, and we found that both SA and HS could specifically bind to PHEV and affect the viral infectivity. Furthermore, the expression of heparan sulfate proteoglycans (HSPGs), including syndecans and glypicans, and endoglycosidase heparinase which cleaves HS were regulated by PHEV RNA replication. Together, we newly identified specificity recognition of cellular glycans and PHEV during infection, providing novel cellular targets for antiviral therapies and better understanding of pathogenesis.