agar and Hepatitis

The central role of T cell activation in hepatocellular injury has been well documented. In this article, we provide evidence suggesting that T cells may also play a protective role in liver disease by releasing interleukin-22 (IL-22), a recently identified T cell-derived cytokine whose biological significance is unclear. IL-22 messenger RNA and protein expression are significantly elevated in T cell-mediated hepatitis induced by concanavalin A (ConA) but are less extensively elevated in the carbon tetrachloride-induced liver injury model. Activated CD3(+) T cells are likely responsible for the production of IL-22 in the liver after injection of ConA. The IL-22 receptor is normally expressed at high levels by hepatocytes and further induced after ConA injection. IL-22 blockade with a neutralizing antibody reduces signal transducer and activator of transcription factor 3 (STAT3) activation and worsens liver injury in T cell-mediated hepatitis, whereas injection of recombinant IL-22 attenuates such injury. In vitro treatment with recombinant IL-22 or overexpression of IL-22 promotes cell growth and survival in human hepatocellular carcinoma HepG2 cells. Stable overexpression of IL-22 in HepG2 cells constitutively activates STAT3 and induces expression of a variety of antiapoptotic (e.g., Bcl-2, Bcl-xL, Mcl-1) and mitogenic (e.g., c-myc, cyclin D1, Rb2, CDK4) proteins. Blocking STAT3 activation abolishes the antiapoptotic and mitogenic actions of IL-22 in hepatic cells. In conclusion, the T cell-derived cytokine IL-22 is a survival factor for hepatocytes; this suggests that T cell activation may also prevent and repair liver injury by releasing hepatoprotective cytokine IL-22 in addition to its previously documented central role in hepatocellular injury.

Topics: Agar; Animals; Carcinoma, Hepatocellular; Cell Division; Cell Line, Tumor; Cell Survival; Chemical and Drug Induced Liver Injury; Concanavalin A; DNA-Binding Proteins; Hepatitis; Hepatocytes; Humans; Interleukin-22; Interleukins; Liver Neoplasms; Mice; Mice, Nude; Neoplasm Transplantation; Receptors, Interleukin; STAT3 Transcription Factor; T-Lymphocytes; Trans-Activators

Topics: Agar; Chemical and Drug Induced Liver Injury; Colorimetry; Electrophoresis; Hepatitis; Hepatitis A; Humans; Isoenzymes; L-Lactate Dehydrogenase

Topics: Agar; Alleles; Arthritis, Rheumatoid; Diabetes Mellitus; Electrophoresis; Gels; Hepatitis; Humans; Hyperlipidemias; Leprosy; Phenotype; Polymorphism, Genetic; Serologic Tests

Topics: Agar; Animals; Biopsy; Carbon Tetrachloride Poisoning; Chemical and Drug Induced Liver Injury; Electrophoresis; Gels; Hepatitis; Histocytochemistry; Humans; Liver Cirrhosis; Liver Diseases; Proteins; Rabbits; Rats; Thioacetamide

Topics: Acyltransferases; Agar; Bile Duct Neoplasms; Biliary Tract Diseases; Cholelithiasis; Electrophoresis; Glutamates; Hepatitis; Humans; Isoenzymes; Jaundice; Liver Cirrhosis; Liver Diseases; Liver Neoplasms; Pancreatic Diseases; Pancreatic Neoplasms; Pancreatitis

A matrix gel diffusion (MGD) procedure with a sensitivity comparable to the complement fixation test (CF) has been developed for detecting Australia antigen in serum. The test utilizes a thin layer of agar (0.1 mm) with an applied plastic matrix. Reactants are introduced directly onto the surface of the agar through wells in the plastic matrix. End points obtained by CF with a panel of 11 sera varied from 1:8 to 1:512. When these sera were tested by MGD, end points for detection of antigen were within one dilution of that obtained by CF.

Topics: Agar; Animals; Complement Fixation Tests; Erythrocytes; Haplorhini; Hepatitis; Hepatitis B virus; Hepatitis, Animal; Humans; Immune Sera; Immunodiffusion; Methods; Plastics; Sheep; Staining and Labeling; Tannins; Thiazines

Topics: Acute Disease; Agar; Alanine; Alkaline Phosphatase; Amides; Aminohydrolases; Anilides; Cholestasis; Chronic Disease; Electrophoresis; Hepatitis; Humans; Isoenzymes; Leucine; Liver Cirrhosis; Liver Diseases; Liver Neoplasms; Naphthalenes; Nitro Compounds; Pancreatic Diseases; Pancreatitis

Topics: Agar; Cellulose; Cholestasis; Diabetes Mellitus; Electrophoresis; Follow-Up Studies; Gels; Hepatitis; Humans; Lipoproteins; Liver Cirrhosis; Medical Records; Methods; Nephrosis

Topics: Agar; Alcoholism; Diabetes Complications; Fatty Liver; gamma-Globulins; Hepatitis; Humans; Immunodiffusion; Immunoglobulin G; Immunoglobulin M; Liver Cirrhosis; Liver Diseases; Liver Function Tests; Methods; Time Factors

Topics: Agar; Antibodies; Antibody Formation; Blood Transfusion; Electrophoresis; Hemophilia A; Hepatitis; Hepatitis B Antigens; Hepatitis B virus; Humans; Immune Sera; Methods; Precipitin Tests; Thalassemia

Topics: Agar; Antigen-Antibody Reactions; Hepatitis; Hepatitis A; Immune Sera; Liver Diseases

Topics: Agar; Antigen-Antibody Reactions; Clinical Laboratory Techniques; Communicable Diseases; Hepatitis; Hepatitis A; Humans; Immunologic Tests

Topics: Agar; Antigen-Antibody Reactions; Bilirubin; Blood Chemical Analysis; Communicable Diseases; Hemagglutination; Hepatitis; Hepatitis A; Humans; Hyperbilirubinemia; Immunologic Tests

Topics: Agar; Epidemics; Hepatitis; Hepatitis A; Humans; Lipoproteins; Lipoproteins, LDL