Pre-acute hepadnaviral infection is associated with activation-induced apoptotic death of lymphocytes in the woodchuck (Marmota monax) model of hepatitis B

Woodchucks (Marmota monax) infected with woodchuck hepatitis virus (WHV) represent a highly valuable immunopathogenic model of hepatitis B virus (HBV) infection. Both WHV and HBV are noncytopathic hepadnaviruses which induce a strong but delayed virus-specific cellular immune response believed to be a cause of hepatitis. The reason behind this postponement is not well understood and its dissection in the woodchuck model has been hampered by the lack of appropriate research tools. In this study, we applied an assay for the simultaneous detection of cell apoptosis and proliferation to determine the fate of T lymphocytes after WHV infection leading to acute hepatitis. The results revealed that pre-acute WHV infection is associated with the significantly heightened susceptibility of T lymphocytes to activation-induced apoptotic death. This suggests that T lymphocyte function is compromised very early in the course of hepadnaviral infection and this may directly contribute to the postponement of virus-specific T cell response.