The pathogenesis of autoimmune liver diseases is poorly understood. Animal models are necessary to investigate antigen presentation and priming of T-cells in the context of autoimmunity in the liver. Transgenic mouse models were generated in which the model antigen ovalbumin is expressed in hepatocytes (TF-OVA) or cholangiocytes (ASBT-OVA). A utoimmune hepatitis and cholangitis are triggered by autoreactive T-cells. Animal models are needed to study the early events in their pathogenesis, namely, the priming of autoreactive T-cells. The requirements for an immune-based animal model are restriction of the immune response to the liver, antigen specificity, and the potential to study the priming of CD8 and CD4 T-cells. Several animal models of autoimmune hepatitis have been developed, 1 none of which fulfills these criteria. Transgenic expression of foreign major histocompatibility complex (MHC) class I molecules in the liver has been widely used. [2][3][4] However, this model has a significant disadvantage: unlike the pathophysiology of an immune or autoimmune reaction, CD8 T cells recognize their antigen on hepatocytes but the antigen is not presented by professional antigen-presenting cells (APCs) in this model. Injection of the synthetic peptide ova p257-264 (SIINFEKL) into mice followed by transfer of antigenspecific CD8 T-cells has also been used, 5 but the possibility of peptide binding to MHC-I molecules on T-cells themselves and their activation by each other 6 or by unrelated cells is a possible concern. Infection with virus expressing ovalbumin 7 results in temporary expression of ovalbumin but also activation of innate immune mechanisms. No animal model exists that allows the simulta-