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Autoimmune Cholangitis (autoimmune + cholangitis)

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Medical Sciences	100%

Selected Abstracts

Deletion of interleukin-6 in mice with the dominant negative form of transforming growth factor , receptor II improves colitis but exacerbates autoimmune cholangitis,

HEPATOLOGY, Issue 1 2010
Weici Zhang
The role of interleukin-6 (IL-6) in autoimmunity attracts attention because of the clinical usage of monoclonal antibodies to IL-6 receptor (IL-6R), designed to block IL-6 pathways. In autoimmune liver disease, activation of the hepatocyte IL-6/STAT3 (signal transducer and activator of transcription 3) pathway is associated with modulating pathology in acute liver failure, in liver regeneration, and in the murine model of concanavalin A,induced liver inflammation. We have reported that mice expressing a dominant negative form of transforming growth factor , receptor II (dnTGF,RII) under control of the CD4 promoter develop both colitis and autoimmune cholangitis with elevated serum levels of IL-6. Based on this observation, we generated IL-6,deficient mice on a dnTGF-,RII background (dnTGF,RII IL-6,/,) and examined for the presence of antimitochondrial antibodies, levels of cytokines, histopathology, and immunohistochemistry of liver and colon tissues. As expected, based on reports of the use of anti,IL-6R in inflammatory bowel disease, dnTGF,RII IL-6,/, mice manifest a dramatic improvement in their inflammatory bowel disease, including reduced diarrhea and significant reduction in intestinal lymphocytic infiltrates. Importantly, however, autoimmune cholangitis in dnTGF,RII IL-6,/, mice was significantly exacerbated, including elevated inflammatory cytokines, increased numbers of activated T cells, and worsening hepatic pathology. Conclusion: The data from these observations emphasize that there are distinct mechanisms involved in inducing pathology in inflammatory bowel disease compared to autoimmune cholangitis. These data also suggest that patients with inflammatory bowel disease may not be the best candidates for treatment with anti,IL-6R if they have accompanying autoimmune liver disease and emphasize caution for therapeutic use of anti,IL-6R antibody. HEPATOLOGY 2010 [source]

Experimental autoimmune cholangitis: a mouse model of immune-mediated cholangiopathy

LIVER INTERNATIONAL, Issue 5 2000
David E. J. Jones
Abstract:Background: Primary biliary cirrhosis (PBC) is characterised by intra-hepatic immune-mediated cholangiopathy (non-suppurative destructive cholangitis (NSDC)). Although auto-reactive immune responses against pyruvate dehydrogenase complex (PDC) have been characterised in PBC, the lack of an animal model of the disease has limited study of the mechanisms of disease induction and the development of novel approaches to therapy. Aims: To develop and validate a mouse model of immune-mediated cholangiopathy relevant for future use in the study of the aetio-pathogenesis and therapy of PBC. Methods: Female SJL/J, C57BL/6, NOD and BALB/c mice were sensitised with PDC, its purified E2/E3BP component, and a PDC-E2 derived peptide p163 (a dominant T-cell epitope in humans) in complete Freund's adjuvant (CFA). Morphological changes were assessed under light microscopy by a hepatic histopathologist blinded to the experimental details. Antibody responses to PDC were studied by ELISA and PDC inhibition assay. Results: An initial series of experiments was performed to survey the susceptibility of female mice of a range of strains to the induction of NSDC by i.p. sensitisation with PDC, PDC-E2/E3BP or p163 in CFA. Although each animal showed a specific antibody response following sensitisation, it was found that NSDC development (assessed at 30 weeks post-sensitisation) was restricted to SJL/J mice following sensitisation with any of the mitochondrial antigen preparations. A subsequent series of experiments was performed to examine the specificity and aetiology of this disease. Significant bile duct lesions were only seen in SJL/J animals following sensitisation with CFA containing PDC, and were absent from CFA only and un-sensitised controls. Kinetic analysis revealed that this pathology developed slowly, but a high incidence of animals with severe lesions was observed after 30 weeks. Conclusions: We have described a model of experimental autoimmune cholangitis (EAC) with immunological (anti-PDC antibodies) and histological (immune-mediated cholangiopathy) features suggestive of PBC. This model may be useful in further defining the role of self-tolerance breakdown in the development of this condition. [source]