Infection and uptake of duck hepatitis B virus by duck hepatocytes maintained in the presence of dimethyl sulfoxide

Primary duck hepatocytes maintained in serum-free culture medium containing dimethyl sulfoxide support efficient replication of duck hepatitis B virus following infection in vitro. Cells remain susceptible to infection for at least 2 weeks after plating, allowing spread of virus via repeat cycles of infection. Up to 100% of cultured hepatocytes can be infected by prolonged exposure to high titer virus inoculum at 37 degrees. We have identified a fraction of infecting virus which binds tightly to cells at 4 degrees, presumably due to association with high affinity receptors on the hepatocyte membrane. The rate at which tightly bound virus is internalized at 37 degrees appears slow, with uptake occurring over a period of at least 16 hr.