Modification of infection pattern of Duck hepatitis B virus by immuno regulatory durgs in both carrier and non-carrier ducks

点击翻译按钮获取中文摘要

To investigate the relationship among the time of viral infection, infection pattern and lever diseases experimental transmission of Duck hepatitis B virus (DHBV) was performed. Inoculation of DHBV into ducks on 1 day and 3 day posthatch revealed persistent infection, whereras inoculation into those on and after 5 day posthatch showed transient viremia. Hepatitis activity was seen in ducks inoculated with DHBV on and after 3 day posthatch and was very weak compared with HBV associated liver diseases. Second, alteration of infection pattern of DHBV by immuno regulatory drugs was investigated. Immunosuprresive treatment with cyclophosphamide extended viremic period and showed almost no hepatic inflammation. Treatment of steroid did not suppress the hepatitis and moreover increased viral replication and extended viremic period. Immuno stimmulation treatment with OK-432 showed increase in hepatic inflammation but did not increase viral replication. Alterations of infection pattern of DHBV with these drugs were quite similar to that of HBV. Host immune response seems to have a considerable role on determination of infection pattern and activity of hepatic inflammation. With these results DHBV can be a helpful model of HBV for studying host-viral interaction and immunological mechanism of viral hepatitis.