LIVER IVM · Imaging liver immunopathology by intravital microscopy

The objective of this proposal is to take advantage of recently developed technological progresses in the field of live imaging to elucidate the pathogenesis of hepatitis B virus (HBV) infection.CD8 T cells play a major part in the development of liver disease and the resolution of HBV infection. A number of important issues pertaining to HBV pathogenesis remain unresolved and they include the way in which CD8 T cells traffic and recognize antigen within the liver and the way in which the diseased liver influences these processes. Our rationale is based on the notion that - at last - we can address these and other related issues experimentally.Single- and two-photon intravital microscopy will be carried out in un-inflamed or fibrotic/cirrhotic livers from mouse models that include transgenic mice that express all of the viral polypeptides and replicate HBV in the hepatocyte and normal mice infected with HBV-replicating, hepatotropic, fluorescent adenoviruses. The spatial and temporal constraints of naïve or effector HBV-specific CD8 T cells recognizing viral antigens and interacting intrahepatically with platelets, endothelial cells or Kupffer cells will be visualized thanks to experimental systems created specifically for this purpose.These studies will shed new light on previously unknown aspects of HBV pathogenesis, paving the road to new immunotherapeutic strategies aimed at terminating chronic HBV infection. Results from this proposal may also have far-reaching implications, not only in related liver infections (i.e. hepatitis C virus), but also in other T cell-mediated pathological conditions of the liver such as autoimmunity, graft rejection or cancer.