In most autoimmune diseases the serologic hallmarks of disease precede clinical pathology by years. Therefore the use of animal models in defining early disease events becomes critical. Herein we have taken advantage of a “designer” mouse with dysregulation of interferon gamma (IFNγ) characterized by prolonged and chronic expression of IFNγ through deletion of the IFNγ 3′ UTR AU-rich element. These mice develop primary biliary cholangitis (PBC) with a female predominance that mimics human disease and is characterized by upregulation of total bile acids, spontaneous production of AMA, and portal duct inflammation. Transfer of CD4 T cells from ARE-Del−/− to B6/Rag1−/− mice induced moderate portal inflammation, and parenchymal inflammation, RNA-sequencing of liver gene expression revealed that upregulated genes potentially define early stages of cholangitis. Interestingly, upregulated genes specifically overlap with the gene expression signature of biliary epithelial cells in PBC, implying that IFNγ may play a pathogenic role in biliary epithelial cells (BEC) in the initiation stage of PBC. Moreover, differentially expressed genes in female mice have stronger Type I and II interferon signaling and lymphocyte-mediated immune responses and thus may drive the female bias of the disease. In conclusion, changes in IFNγ expression are critical for the pathogenesis of PBC.

Immunotherapy with IL-2 and anti-CD40 induces the expression of NOS2 in tumor-associated macrophages, and its expression is required for the inhibition of tumor metastasis.