Heparin inhibits plaque formation by cell-free Marek's disease viruses in vitro

The mechanisms of Marek's disease virus (MDV) entry to host cells have not yet been analyzed. Heparan sulfate (HS) on the cell surface serves as a receptor for several herpesviruses in mammalian species. In this study, we demonstrated that plaque formation by cell-free MDV is inhibited by the addition of soluble heparin to the cell culture. Moreover, pretreatment of susceptible cells, chicken embryo fibroblasts, with heparinase, partially reduced infectivity of the cell-free MDV. From these results, it was suggested that the MDV entry, at least in the case of cell-free MDV, is dependent on the presence of cell surface glycosaminoglycans, principally HS.