There have been important advances in defining effector mechanisms for several human autoimmune diseases. However, for most human autoimmune diseases, the induction stage is less well defined and there are very few clues on etiology. Our laboratory has focused on defining the molecular basis of autoantibody recognition and epitope modification in primary biliary cirrhosis (PBC). Our work has demonstrated that antibodies to mitochondria (AMA), the hallmark of disease, are directed against a very conserved site of pyruvate dehydrogenase (PDCE2). We have also demonstrated that several chemical xenobiotics, chosen based on quantitative structural activity relationship analysis and rigorous epitope analysis, when coupled to the lysine residue that normally binds the lipoic acid co-factor of PDC-E2, reacts as well or better to PBC sera than native autoantigen. In the present studies, we immunized C57BL/6 mice with one such xenobiotic, 2-octynoic acid (2OA), coupled to bovine serum albumin (BSA) and followed mice for 24 weeks. Animals were studied for appearance of histologic lesions as well as appearance of antibodies to PDC-E2, serum levels of TNF-α and IFN-γ and splenic and liver lymphoid phenotyping by flow cytometry. Mice immunized with 2OA manifest autoimmune cholangitis, typical mitochondrial autoantibodies, increased liver lymphoid cell numbers, an increase in CD8+ liver infiltrating cells, particularly CD8+ T cells that co-express CD44, and finally an elevation of serum TNF-α and IFN-γ. In conclusion, these data provide a persuasive argument in favor of an environmental origin for human PBC.