Suppression of immune-mediated liver injury after vaccination with attenuated pathogenic cells

Regulatory T Cells in Autoimmune Hepatitis: Unveiling Their Roles in Mouse Models and Patients

Autoimmune hepatitis (AIH) is a severe and chronic liver disease, and its incidence has increased worldwide in recent years. Research into the pathogenesis of AIH remains limited largely owing to the lack of suitable mouse models. The concanavalin A (ConA) mouse model is a typical and well-established model used to investigate T cell-dependent liver injury. However, ConA-induced hepatitis is acute and usually disappears after 48 h; thus, it does not mimic the pathogenesis of AIH in the human body. Several studies have explored various AIH mouse models, but as yet there is no widely accepted and valid mouse model for AIH. Immunosuppression is the standard clinical therapy for AIH, but patient side effects and recurrence limit its use. Regulatory T cells (Tregs) play critical roles in the maintenance of immune homeostasis and in the prevention of autoimmune diseases, which may provide a potential therapeutic target for AIH therapy. However, the role of Tregs in AIH has not yet been clarified, partly because of difficulties in diagnosing AIH and in collecting patient samples. In this review, we discuss the studies related to Treg in various AIH mouse models and patients with AIH and provide some novel insights for this research area.

Emerging opportunities for site-specific molecular and cellular interventions in autoimmune hepatitis

Current corticosteroid-based treatments of autoimmune hepatitis frequently have incomplete or unsatisfactory outcomes, side effects, and excessive immune suppression. The goal of this review is to describe the advances in developing animal models of autoimmune hepatitis and in treating diverse immune-mediated diseases that make pursuit of site-specific molecular and cellular inventions in autoimmune hepatitis feasible. Prime source and review articles in English were selected by a Medline search through October 2009. A murine model infected with an adenovirus expressing human CYP2D6 is a resource for evaluating new therapies because of its histological and serological features, persistence, and progressive hepatic fibrosis. Synthetic analog peptides that block autoantigen expression, a dimeric recombinant human fusion protein of cytotoxic T lymphocyte antigen-4, monoclonal antibodies against tumor necrosis factor-alpha, recombinant interleukin 10, tolerization techniques for disease-triggering autoantigens, T regulatory cell transfer, vaccination against antigen-specific cytotoxic CD8+ T cells, and gene silencing methods using small inhibitory RNAs are feasible interventions to explore. Treatments directed at dampening immunocyte activation with soluble cytotoxic T lymphocyte antigen-4, inhibiting immunocyte differentiation with recombinant interleukin 10, and improving immunosuppressive activity with regulatory T cell modulation have the most immediate promise. Progress in the development of an animal model of autoimmune hepatitis and experiences in other immune-mediated diseases justify the evaluation of site-specific molecular and cellular interventions in this disease.

Synergistic hepatoprotective effect of Schisandrae lignans with Astragalus polysaccharides on chronic liver injury in rats

The aim of this study was to investigate the synergistic hepatoprotective effect of lignans from Fructus Schisandrae chinensis (LFS) with Astragalus polysaccharides (APS) on chronic liver injury in male Sprague-Dawley rats. Subcutaneous injection of 10% CCl(4) twice a week for 3 months resulted in significantly (p<0.001) elevated serum alanine aminotransferase (ALT), asparate aminotransferase (AST), alkaline phosphatase (ALP) activities compared to controls. In the liver, significantly elevated levels (p<0.001) of malondialdehyde (MDA), lowered levels of reduced glutathione (GSH) (p<0.05) and catalase (CAT) (p<0.001), superoxide dismutase (SOD) (p<0.01)were observed following CCl(4) administration. 'LFS+ASP' treatment of rats at doses of 'LFS (45mg/kg)+APS (150mg/kg)' and 'LFS (135mg/kg)+APS (450mg/kg)' displayed hepatoprotective and antioxidative effects than the administration of either LFS or APS, as evident by lower (p<0.005 or 0.001) levels of serum ALT, AST, ALP and hepatic MDA (p<0.001) concentration, as well as higher SOD (p<0.05 or 0.005), CAT activities(p<0.01 or 0.005), GSH concentration (p<0.05 or 0.005) compared to the toxin treated group. Histopathological examinations revealed severe fatty degeneration in the toxin group, and mild damage in groups treated with 'LFS+APS' were observed. The coefficients drug interaction (CDI) between each individual drug and their combination (at the same dose of their single treatment) of these foregoing parameters were all less than 1, indicating that LFS and APS display hepatoprotective and antioxidant properties and act in a synergistic manner in CCl(4) induced liver injury in rats.