concanavalin-a and Hepatitis--Chronic

Autoimmune chronic active hepatitis is a disease of unknown aetiology in which a dense mononuclear cell infiltrate in the portal areas of the liver is associated with ongoing necrosis of periportal hepatocytes. The finding of autoantibodies in serum, an increased frequently of HLA B8 DR3, a female predominance, an association with autoimmune diseases and the histological features all suggest a role for immunological reactions in the pathogenesis. Various immunological reactions have been demonstrated in vitro which could be of relevance to pathogenesis, including antibodies in serum directed against antigens expressed on the liver cell membrane, antibody-dependent cell-mediated cytotoxicity for autologous hepatocytes. T cell sensitisation to undefined hepatocyte antigen(s) and both antigen- and non-antigen-specific suppressor T cell defects. However, it is still unclear how these various phenomena interact in vivo and further studies are required to clarify their exact role in pathogenesis.

Topics: Antibody-Dependent Cell Cytotoxicity; Autoantibodies; Autoimmune Diseases; Cell Membrane; Concanavalin A; Female; Hepatitis, Chronic; Histocompatibility Antigens Class II; HLA Antigens; HLA-B8 Antigen; HLA-DR3 Antigen; Humans; Immunity, Cellular; Liver; Male; T-Lymphocytes, Regulatory

Chronic inflammation is strongly associated with an increased risk for hepatocellular carcinoma (HCC) development. The multidrug resistance 2 (Mdr2)-knockout (KO) mouse (adenosine triphosphate-binding cassette b4(-/-) ), a model of inflammation-mediated HCC, develops chronic cholestatic hepatitis at an early age and HCC at an adult age. To delineate factors contributing to hepatocarcinogenesis, we compared the severity of early chronic hepatitis and late HCC development in two Mdr2-KO strains: Friend virus B-type/N (FVB) and C57 black 6 (B6). We demonstrated that hepatocarcinogenesis was significantly less efficient in the Mdr2-KO/B6 mice versus the Mdr2-KO/FVB mice; this difference was more prominent in males. Chronic hepatitis in the Mdr2-KO/B6 males was more severe at 1 month of age but was less severe at 3 months of age in comparison with age-matched Mdr2-KO/FVB males. A comparative genome-scale gene expression analysis of male livers of both strains at 3 months of age revealed both common and strain-specific aberrantly expressed genes, including genes associated with the regulation of inflammation, the response to oxidative stress, and lipid metabolism. One of these regulators, galectin-1 (Gal-1), possesses both anti-inflammatory and protumorigenic activities. To study its regulatory role in the liver, we transferred the Gal-1-KO mutation (lectin galactoside-binding soluble 1(-/-) ) from the B6 strain to the FVB strain, and we demonstrated that endogenous Gal-1 protected the liver against concanavalin A-induced hepatitis with the B6 genetic background but not the FVB genetic background.. Decreased chronic hepatitis in Mdr2-KO/B6 mice at the age of 3 months correlated with a significant retardation of liver tumor development in this strain versus the Mdr2-KO/FVB strain. We found candidate factors that may determine strain-specific differences in the course of chronic hepatitis and HCC development in the Mdr2-KO model, including inefficient anti-inflammatory activity of the endogenous lectin Gal-1 in the FVB strain.

Topics: Animals; ATP Binding Cassette Transporter, Subfamily B; ATP-Binding Cassette Sub-Family B Member 4; Carcinoma, Hepatocellular; Cell Transformation, Neoplastic; Chemical and Drug Induced Liver Injury; Concanavalin A; Galectin 1; Hepatitis, Chronic; Liver; Liver Neoplasms; Male; Methionine Adenosyltransferase; Mice; Mice, Inbred Strains; Mice, Knockout

Nephronectin (Npnt) is an extracellular matrix protein known to play a critical role in kidney development; however, its physiological role in the liver remains elusive. Here we show that Npnt expression is upregulated in mouse models of both acute and chronic hepatitis induced by Concanavalin A (Con A) and 3,5-diethocarbonyl-1,4-dihydrocollidine (DDC), respectively. In both models, Npnt was localized in inflammatory foci and was mainly secreted from mesenchymal cells and in part by cholangiocytes. Interestingly, ectopic expression of Npnt in hepatocytes induced the development of granuloma-like cell clusters mainly composed of CD4(+) T cells or NKT cells but did not induce apparent hepatitis. Furthermore, we found that Npnt exacerbated the Con A-induced acute hepatitis. These results indicate that Npnt plays an important role in the initiation of hepatitis by recruiting CD4(+) T cells or NKT cells into the foci of inflammation. In addition, we reveal that Npnt expression is also upregulated in human hepatitis. Therefore, Npnt may be a potential therapeutic target for acute and chronic hepatitis.

Topics: Acute Disease; Animals; CD4-Positive T-Lymphocytes; Cell Movement; Concanavalin A; Disease Models, Animal; Disease Progression; Extracellular Matrix Proteins; Gene Expression Regulation; Granuloma; Hepatitis; Hepatitis, Chronic; Liver; Male; Mice; Mice, Inbred C57BL; Up-Regulation

Tenascin-C (TNC), an extracellular matrix glycoprotein, is upregulated in chronic liver disease. Here, we investigated the contribution of TNC to liver fibrogenesis by comparing immune-mediated hepatitis in wild-type (WT) and TNC-null (TNKO) mice. Eight-week-old BALB/c mice received weekly intravenous injections of concanavalin A to induce hepatitis, and were sacrificed one week after the 3rd, 6th, 9th, and 12th injections. In WT livers, immunohistochemical staining revealed a gradual increase in TNC deposition. TNC mRNA levels also increased sequentially and peaked after the 9th injection. Collagen deposition, stained with picrosirius red, was significantly less intense in TNKO mice than in WT mice, and procollagen I and III transcripts were significantly upregulated in WT mice compared with TNKO mice. Inflammatory infiltrates were most prominent after the 3rd-6th injections in both groups and were less intense in TNKO mice than in WT mice. Interferon-gamma, tumour necrosis factor-alpha, and interleukin-4 mRNA levels were significantly higher in WT mice than in TNKO mice, while activated hepatic stellate cells (HSCs) and myofibroblasts, a cellular source of TNC and procollagens, were more common in WT livers. Transforming growth factor (TGF)-beta1 mRNA expression was significantly upregulated in WT mice, but not in TNKO mice. In conclusion, TNC can promote liver fibrogenesis through enhancement of inflammatory response with cytokine upregulation, HSC recruitment, and TGF-beta expression during progression of hepatitis to fibrosis.

Topics: Animals; Concanavalin A; Female; Hepatitis, Chronic; Immunohistochemistry; Interferon-gamma; Interleukin-4; Liver Cirrhosis; Lymphocytes; Mice; Mice, Inbred BALB C; Mice, Knockout; Procollagen; Reverse Transcriptase Polymerase Chain Reaction; RNA; Tenascin; Transforming Growth Factor beta1

Patients with hepatitis have multiple immunologic abnormalities, which may be related to cytokine production.. We examined the in vitro production of interleukins (IL-2, IL-4, IL-6), tumor necrosis factor-alpha (TNF-alpha), and interferon-gamma (IFN-gamma) in purified peripheral blood mononuclear cells (PBMCs) of patients with hepatitis B virus positive (HBV), acute viral hepatitis (A-HBV), HBV + chronic active hepatitis (HBV-CAH), and autoimmune-type chronic active hepatitis (AI-ACH).. IFN-gamma and TNF-alpha production were characteristically higher in patients with A-HBV than in healthy control subjects (p < 0.001). However, patients with AI-CAH produced highly elevated levels of IL-4 and IL-6 compared with patients with A-HBV and HBV-CAH and healthy control subjects. The cytokine profile (PBMC-induced IL-2, IL-4, IL-6, IFN-gamma, and TNF-alpha production) is different in A-HBV, HBV-CAH, and AI-CAH disease. The increased cytokine secretion (IFN-gamma and TNF-alpha in A-HBV and IL-4 and IL-6 in AI-CAH) could reflect altered relative frequencies of different cell phenotypes in these diseases.. Specific cytokine production may be important in the pathophysiology associated with diverse inflammatory states in patients with hepatitis.

Topics: Adult; Autoimmune Diseases; Calcimycin; Concanavalin A; Cytokines; Female; Hepatitis B; Hepatitis, Chronic; Humans; In Vitro Techniques; Interferon-gamma; Interleukin-2; Interleukin-4; Interleukin-6; Leukocytes, Mononuclear; Male; Tetradecanoylphorbol Acetate; Tumor Necrosis Factor-alpha

Isozymic alteration of serum cholinesterase (ChE) was investigated in patients with chronic liver diseases using affinity electrophoresis with concanavalin A (Con A) or wheat germ agglutinin (WGA). On Con A-containing agarose gel electrophoresis, three bands with enzyme activity (named bands I to III, from the anodic side to the cathodic) were observed in sera of normal controls. Disappearance of band II was observed in 50% (15/30) of cirrhotic patients, but only one of 20 patients with chronic hepatitis lacked band II of the serum ChE isozymes. Meanwhile, WGA-containing agarose gel electrophoresis revealed that normal controls had four ChE isozymes (named bands I to IV from the anodic side to the cathodic). These four isozymes were also observed in patients with chronic hepatitis. However approximately 67% (20/30) of cirrhotic patients lacked band II of ChE isozymes. When these two affinity electrophoreses were used in combination, 22 (73%) of 30 cirrhotic patients had isozymic alteration of their serum ChE on either Con A-containing or WGA-containing agarose gel electrophoresis, or both. Thus, affinity electrophoreses with Con A and WGA seemed to be useful methods in differentiating liver cirrhosis from chronic hepatitis.

Topics: Cholinesterases; Clinical Enzyme Tests; Concanavalin A; Diagnosis, Differential; Electrophoresis, Agar Gel; Hepatitis, Chronic; Humans; Isoenzymes; Liver Cirrhosis; Wheat Germ Agglutinins

Suppressor T-cell activity and allogeneic T-cell response to concanavalin A (ConA) were investigated in 46 patients chronically infected with hepatitis B virus (HBV). Thirty-eight patients had chronic active hepatitis, seven of whom were superinfected with Delta virus, and eight were healthy chronic HBV carriers. T-cell suppressor activity was in the normal range in healthy carriers and in patients negative for serum HBV-DNA, independent of the e antigen status. In contrast, the group of patients positive for HBV-DNA exhibited a significant reduction in suppressor activity. Longitudinal studies in patients who cleared serum HBV-DNA demonstrated that suppressor T-cell activity became normal thereafter. These results suggest a relationship between suppressor T-cell function and the stage of viral replication in individuals with chronic HBV infection.

Topics: Adult; Aged; Carrier State; Chronic Disease; Concanavalin A; DNA Replication; DNA, Viral; Female; Hepatitis B; Hepatitis B virus; Hepatitis, Chronic; Humans; Immunity, Cellular; Longitudinal Studies; Lymphocyte Activation; Male; Middle Aged; T-Lymphocytes, Regulatory; Virus Replication

Concanavalin A-activated T-lymphocyte suppression of IgG production was found to be significantly impaired in patients with untreated active autoimmune chronic hepatitis when compared to normals or patients with inactive disease. When the dose-response effect of TP-1, a calf thymic extract, on in vitro suppressor cell activity was assessed, lymphocytes from six out of eight patients with previously reduced suppressor cell function showed a significant improvement, while over a similar range the suppressor cell activity of most normal controls declined. These results support the possibility that defective immunoregulation in patients with autoimmune chronic active hepatitis may be related to a deficiency in thymic hormone levels.

Topics: Adjuvants, Immunologic; Adult; Aged; Autoimmune Diseases; Concanavalin A; Female; Hepatitis, Chronic; Humans; Immunoglobulin G; In Vitro Techniques; Male; Middle Aged; T-Lymphocytes, Regulatory; Thymus Extracts

In autoimmune chronic active hepatitis (aCAH), autoaggression is believed to derive from a defect in immunoregulation. Antigen non-specific Concanavalin A (Con A) induced suppressor cell function has been reported to be impaired. In 11 children with aCAH we have investigated inhibition of production of a specific antibody (anti-tetanus toxoid, anti-TT) by suppressor cells induced either by a non-specific stimulus (Con A) or by the specific antigen (tetanus toxoid, TT). Con A induced suppression of anti-TT was significantly lower in patients (15.7 +/- 2.5%) than in controls (46.7 +/- 4.4%; P less than 0.01). In contrast, high dose tetanus toxoid induced suppression was similar in patients and controls (69.8 +/- 4.2, 72.0 +/- 3.6%, respectively). Both groups had similar serum anti-TT levels and in vitro production of anti-TT in response to optimal dose of TT. Our data indicate that antibody production to a T cell-dependent antigen is under the control of at least two regulatory mechanisms, one antigen specific and one antigen non-specific, only the latter being defective in aCAH.

Topics: Adolescent; Antibodies, Bacterial; Autoimmune Diseases; Child; Concanavalin A; Epitopes; Female; Hepatitis, Chronic; Humans; Male; T-Lymphocytes, Regulatory; Tetanus Toxoid

To investigate the relationship between liver damage and immune regulation in hepatitis B virus (HBV) infection, 68 patients with HBsAg in serum and a spectrum of liver damage have been studied and compared with 25 controls. In HBsAg carriers, spontaneous IgG production was elevated only in those with chronic active hepatitis (P less than 0.05) whilst those with less severe inflammation had values comparable to normals. Concanavalin A (Con A) induced suppressor cell regulation of IgG producing cells was impaired in those with chronic active hepatitis (P less than 0.01) and those with chronic persistent hepatitis (P = 0.05) and there was a correlation in both groups of patients with the severity of portal tract inflammation (P less than 0.05). In contrast those with minimal liver damage had values in the normal range. Patients presenting with acute hepatitis B also had elevated spontaneous IgG production (P less than 0.01) and impaired Con A induced suppressor cell regulation of IgG production (P less than 0.01). Sequential study of three patients prior to the detection of HBsAg in serum and subsequently during and after acute hepatitis B showed that such abnormalities were transient and closely related to the onset of liver damage.

Topics: Adult; Antibody-Producing Cells; Concanavalin A; Female; Hepatitis B; Hepatitis B Antigens; Hepatitis delta Antigens; Hepatitis, Chronic; Humans; Immunoglobulin G; In Vitro Techniques; Liver; Lymphocyte Activation; Male; Middle Aged; T-Lymphocytes, Regulatory; Time Factors; Transaminases

Topics: Adult; Concanavalin A; Female; Hepatitis B; Hepatitis, Chronic; Humans; Interferon Type I; Interferon-gamma; Male; Newcastle disease virus; T-Lymphocytes

Con A stimulated suppressor cell function and the proportion of suppressor T cells were reduced in children with untreated chronic active hepatitis (CAH) but were normal in corticosteroid treated CAH patients, patients with severe acute hepatitis and inactive chronic liver disease. Adults with CAH also have defective suppressor function but a normal proportion of T suppressor cells. This difference may account for the observation that relapse after treatment withdrawal is less frequent in children than in adults.

Topics: Adolescent; Child; Child, Preschool; Concanavalin A; Female; Hemolytic Plaque Technique; Hepatitis; Hepatitis, Chronic; Humans; Immunoglobulin G; Immunoglobulin M; Leukocyte Count; Liver Diseases; Male; Pokeweed Mitogens; T-Lymphocytes, Cytotoxic; T-Lymphocytes, Helper-Inducer; T-Lymphocytes, Regulatory

Mitogen-induced suppressor T lymphocyte function was evaluated in patients with chronic active hepatitis (CAH). The in vitro effect of the biological response modifier, thymosin fraction 5, on the suppressive activity of peripheral blood mononuclear cells (PBM) was also assessed. Suppressor cell activity was significantly decreased in patients with CAH when compared to controls (P less than 0.001). In the absence of the inducing mitogen, thymosin-treated PBM from both patients and controls promoted enhancement of tritiated thymidine uptake by cocultured allogeneic lymphocytes. When thymosin-treated mononuclear cells were mitogen-activated; patients, but not the controls, showed a marked increase in suppressor activity (P less than 0.001). These results indicate that the polypeptides contained in thymosin fraction 5 can promote a helper effect in patients and controls. Furthermore, PBM from patients with CAH contain a subset of lymphocytes that can express a suppressive function following thymosin treatment. We conclude that thymosin fraction 5 can promote an in vitro restoration of suppressor T cell function in patients with CAH.

Topics: Adolescent; Adult; Concanavalin A; Dose-Response Relationship, Drug; Female; Hepatitis, Chronic; Humans; Liver Cirrhosis; Liver Function Tests; Male; Middle Aged; Mitogens; Monocytes; Prednisone; T-Lymphocytes, Helper-Inducer; T-Lymphocytes, Regulatory; Thymosin; Thymus Hormones

Peripheral blood B cell response to staphylococcus aureus (SpA) Cowan I was evaluated in 8 healthy subjects, 8 patients with liver cirrhosis (LC), and 2 patients with chronic active hepatitis (CAH) with hypergammaglobulinemia (greater than 2 g/dl). In control studies it was shown that stimulation by SpA Cowan I was much less T cell-dependent than that induced by pokeweed mitogen (PWM) or con-canavalin A (ConA) when the amounts of immunoglobulins (Ig) secreted into culture supernatants were measured by radioimmunoassay (RIA) and the blastogenic response was measured by incorporation of tritiated thymidine. B cells from only 2 patients revealed increased Ig synthesis by SpA Cowan I stimulation. In the study of blastogenic response, increased DNA synthesis of B cells by SpA Cowan I stimulation was observed in 2 patients and decreased DNA synthesis in 3 patients. The remaining patients demonstrated normal range response. There was no correlation between B cell response to SpA Cowan I and clinical data such as gammaglobulin level in the patients studied. These studies indicate that B cell function remains intact in many patients with chronic liver disease with hypergammaglobulinemia.

Topics: Adult; Aged; B-Lymphocytes; Chronic Disease; Concanavalin A; Female; Hepatitis, Chronic; Humans; Immunoglobulin G; Immunoglobulin M; Liver Cirrhosis; Lymphocyte Activation; Male; Middle Aged; Pokeweed Mitogens; Staphylococcus aureus