Porcine epidemic diarrhea virus uses cell-surface heparan sulfate as an attachment factor

It is well known that many viruses use heparan sulfate as the initial attachment factor. In the present study, we determined whether porcine epidemic diarrhea virus (PEDV), an emerging veterinary virus, infects Vero cells by attaching to heparan sulfate. Western blot analysis, real-time PCR, and plaque formation assay revealed that PEDV infection was inhibited when the virus was pretreated with heparin (an analogue of heparan sulfate). There was no inhibitory effect when the cells were pre-incubated with heparin. We next demonstrated that enzymatic removal of the highly sulfated domain of heparan sulfate by heparinase I treatment inhibited PEDV infection. We also confirmed that sodium chlorate, which interferes with heparan sulfate biosynthesis, also inhibited PEDV infection. Furthermore, we examined the effect of two heparin derivatives with different types of sulfation on PEDV infection. The data suggested de-N-sulfated heparin, but not N-acetyl-de-O-sulfated heparin, inhibits PEDV infection. In summary, our studies revealed that heparan sulfate acts as the attachment factor of PEDV in Vero cells.