The asialoglycoprotein receptor mediates hepatic binding and uptake of natural hepatitis B virus particles derived from viraemic carriers.

As a putative mechanism of hepatitis B virus (HBV) uptake into hepatocytes the interaction between HBV and the hepatic, human-derived asialoglycoprotein receptor (ASGPR) was investigated. Sera from patients with different variations of hepatitis B surface antigen-(HBsAg) positive chronic hepatitis, HBV particles isolated from HBV carriers with high-titre viraemia and commercial HBsAg served as sources of HBV. ASGPR was affinity-purified from human liver. HBV that had bound to isolated ASGPR was either detected by radio-immunoassay using solid-phase bound ASGPR or enzyme immunoassay with biotin-ASGPR bound to immobilized HBV. Furthermore, binding and uptake of purified, 125I-labelled HBV par…

Autoantibodies against the human asialoglycoprotein receptor: Effects of therapy in autoimmune and virus-induced chronic active hepatitis

The hepatic asialoglycoprotein receptor (ASGPR) was recently identified as a target antigen for both humoral and cellular immune response in inflammatory liver diseases. Thereby anti-ASGPR autoantibodies directed against human substrate were closely associated with autoimmune chronic active hepatitis. The present study compares the occurrence, titer and immunoglobulin classification of anti-human(h-)-ASGPR antibodies in 23 patients with newly diagnosed autoimmune chronic hepatitis before and after initiation of immunosuppressive therapy to 22 patients with autoimmune hepatitis in remission. Additionally, 1-year follow-up examinations of 42 patients with HBsAg-positive chronic hepatitis and …

Liver Membrane Autoantibodies

Publisher Summary This chapter includes the intensive efforts to standardize the assay, define associations with disease or clinical presentation, and characterize antigenic and biological properties of anti-liver membrane antibodies. The characterization of different target antigens on the hepatic plasma membrane shows a polyvalent and heterogenous humoral immune response against the liver surface. Liver membrane antibodies can induce liver cell damage in vitro, including dysfunction of the target antigen. Among the established liver membrane-related autoantigens, the asialoglycoprotein receptor (ASGPR) represents the only component of the hepatic plasma membrane that is fully characterize…

Anti-neutrophil cytoplasmic antibodies in a rat model of trinitrobenzenesulphonic acid-induced liver injury

Background In sera from patients with autoimmune liver diseases, e.g. primary sclerosing cholangitis (PSC) and autoimmune hepatitis, anti-neutrophil cytoplasmic antibodies (ANCAs) can be found. Until now, no animal model of ANCA induction in liver disease has been described. In this study, we describe a novel rat model of acute liver injury and subsequent ANCA production. Materials and methods The hapten reagent 2,4,6-trinitrobenzenesulphonic acid (TNBS) was injected into the portal vein of female Lewis rats. Two experimental groups were studied: group A (TNBS/ethanol) received different TNBS concentrations; control animals of group B (ethanol) were injected with 10% (v/v) ethanol/0.9% (w/v…

The asialoglycoprotein receptor as target structure in autoimmune liver diseases.

Human asialoglycoprotein receptor as an autoantigen in chronic hepatitis.

ASGPR may play a role in the pathogenesis of autoimmune chronic liver diseases. Several lines of evidence support this hypothesis. Antibodies to rabbit ASGPR could be found in various inflammatory liver diseases. In contrast, ASGPR preparations derived from human liver (h-ASGPR) were recognized predominantly by sera from patients with ai-CAH. Moreover, anti-h-ASGPR showed a close correlation to the inflammatory activity of ai-CAH both in terms of prevalence (88% in histologically proven active diseases), immunoglobulin class (IgM antibodies restricted to active inflammation) and behavior during treatment. Anti-h-ASGPR secretion could also be found in vitro, when PBL of patients were stimula…

Liver-infiltrating T helper cells in autoimmune chronic active hepatitis stimulate the production of autoantibodies against the human asialoglycoprotein receptor in vitro.

SUMMARYAutoantibodies against the human asialoglycoprotein receptor (ASGPR) occur in the sera orpaticnts with autoimmune liver disorders. Live-nfiltrating T cell clones that specifically recognize the ASGPR have been described in patients with autoimmune chronic active hepatitis (A-AH) and primary biliary cirrhosis (PBC). Recently, we have shown that peripheral blood mononuclcar cells (PBMC) from patients with A-AH or PBC but not chronic viral hepatitis secreted ant-SGPR antibodies in vitro. In this study we characterized the influence of live-nfiltrating T cells on the secretion of ASGP-pecific autoantibodies by autologous B cells in cell culture supernatants. T cell clones from liver biop…

Hepatitic C virus infection and autoimmunity : clinical features, diagnostic tools and therapeutical aspects

Summary Since the genom of the hepatitis C virus (HCV) was detected the pathogenesis of a distinct group of chronic liver disease and some non-hepatic disorders of sofar unknown origin could be newly established. A wide variety of clinical features including vasculitis, glomerulonephritis, porphyria and rheumatoid-like symptoms may become apparant separately or in combination. HCV can be precipitated in cryoglobulins and tissue-related HCV was found in liver and kidney specimen, for instance. HCV-related cryoglobulinemia or circulating immune complexes often occur with vasculitis. Hematological changes may be present such as thrombocytopenia. A considerable amount of patients show circulati…

Effects of cytokines on synthesis and function of the hepatic asialoglycoprotein receptor

In this study we have investigated whether cytokines, critical mediators of the immune response, might have a direct effect on the expression and/or function of the human hepatic asialoglycoprotein receptor (ASGPR). Binding and uptake of asialoglycoproteins by the human hepatoma cell line, HepG2, and by freshly isolated rat hepatocytes were inhibited by 50% after 3-6 hours and completely abolished following a 24 hour exposure to tumor necrosis factor (TNF) alpha, interferon (INF) alpha or gamma, or interleukin-2 (IL-2). The loss of ASGPR binding activity mediated by IL-2 was reversible up to 4 hours of exposure and accompanied by the selective phosphorylation of the cell-surface receptor. S…

Soluble E-Selectin Enhances Intercellular Adhesion Molecule-1 (ICAM-1) Expression in Human Tumor Cell Lines

E-selectin mediates neovascularization via its soluble form, while its membrane-bound form initiates binding of tumor cells to vascular endothelium. Therefore, it was studied whether soluble E-selectin regulates further adhesion molecules on tumor cells. In tumor cells but not in related nonmalignant cells, intercellular adhesion molecule (ICAM)-1 expression was strikingly increased from 5 to 68% positive cells by in vitro inoculation of a recombinant E-selectin-IgG1 within 24 h, as analyzed by flow cytometry. The absence of changes in the expression of vascular cell adhesion molecule, integrin ligands (CD11a, CD18, integrin alpha 4), and sialyl-Lewis X indicates a specific effect of solubl…

HCV-associated cryoglobulinaemia presenting with vasculitis, hepatitis, and glomerulonephritis—a therapeutic dilemma

treated by diet. One year prior to presentation the patient suffered a transitory ischaemic brain attack concomitant with the onset of arterial hypertension, which was subsequently treated with calcium antagonists and beta blockers. Purpura-like skin lesions were noted which were reported to have occurred intermittently over a period of 5 years on both legs and occasionally on the arms. Proteinuria and haematuria were noted during periods with skin lesions.

Autoantibodies to human asialoglycoprotein receptor in autoimmune-type chronic hepatitis.

Autoantibodies to the human asialoglycoprotein receptor (anti-h-ASGPR) were studied with a solid-phase ELISA in the sera of 421 patients with inflammatory liver diseases, 288 patients with various other disorders and 31 controls. Anti-h-ASGPR were found predominantly in autoimmune chronic active hepatitis (44 of 88, 50%) and were closely related to inflammatory activity. In a subpopulation of these patients with untreated, biopsy-proven active disease or relapse, 15 of 17 were positive (88%). In contrast, only 11 of 204 patients (5.3%) with viral hepatitis were anti-h-ASGPR receptors-positive (chi 2 analysis; p less than 0.001). We also compared the occurrence of anti-h-ASGPR with antibodie…

The human hepatic asialoglycoprotein receptor is a target antigen for liver-infiltrating T cells in autoimmune chronic active hepatitis and primary biliary cirrhosis.

Autoantibodies to the human hepatic asialoglycoprotein receptor have been found in nearly 50% of the sera of patients with autoimmune chronic active hepatitis and in 15% of patients with primary biliary cirrhosis. In this study we demonstrate that the human hepatic asialoglycoprotein receptor is also a target antigen for T cell-mediated immune responses. Peripheral blood lymphocytes of 37% (7 of 19) of patients with autoimmune chronic active hepatitis and 33% (2 of 6) of patients with primary biliary cirrhosis showed a proliferative response to highly purified human hepatic asialoglycoprotein receptor, whereas no proliferation was found with peripheral blood lymphocytes of patients with chr…

Complete congenital heart block in autoimmune hepatitis (SLA-positive).

Complete congenital heart block is a serious complication of neonatal lupus erythematosus which most often occurs in children of mothers suffering from connective tissue disease. We report the occurrence of complete congenital heart block associated with autoimmune hepatitis (SLA-positive). A 32-year-old woman was treated for more than 10 years for autoimmune hepatitis (SLA-/ANA-positive) and remained in clinical remission under immunosuppressive therapy. She showed an MHC-haplotype typical for autoimmune hepatitis (A1, B8, DR3). After a normal first pregnancy, an emergency caesarean section was performed in the 32nd week of her second pregnancy because of fetal bradycardia. The child died …