Abstract
Con A administration results in dose-dependent immune-mediated liver injury. Cytokines are important to determine the outcome of liver failure in this model, and especially TNF-alpha and IFN-gamma directly contribute to hepatocyte damage. The intracellular pathways of these two cytokines, which eventually result in tissue destruction, are not well defined. Here we used anti-IFN-gamma Abs and adenoviral vectors that express molecules inhibiting distinct TNF-alpha-dependent pathways in hepatocytes to better understand the relevance of specific intracellular signaling cascades for Con A-induced liver failure. We show that activation of TNF-alpha- and IFN-gamma-dependent intracellular pathways occurs prior to the influx of immune-activated cells into the liver and that anti-TNF-alpha and anti-IFN-gamma neutralizing Abs cannot block infiltration of these cells. Blocking experiments with Abs and adenoviral vectors showed that NF-kappaB activation and the Fas-associated death domain protein/caspase 8 cascade in hepatocytes during Con A-induced liver failure have no impact on tissue injury. Additionally, STAT1 activation alone after Con A injection in liver cells does not result in liver damage. In contrast, IFN-gamma-dependent expression of IFN regulatory factor-1 and TNF-alpha-dependent activation of c-Jun N-terminal kinase in liver cells correlates with liver cell damage after Con A injection. Therefore, our experiments indicate that 11418690
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Adaptor Proteins, Signal Transducing*
-
Animals
-
CD4-Positive T-Lymphocytes / pathology
-
Carrier Proteins / metabolism
-
Cell Movement / immunology
-
Concanavalin A / administration & dosage*
-
Concanavalin A / pharmacology
-
DNA-Binding Proteins / antagonists & inhibitors
-
DNA-Binding Proteins / metabolism
-
DNA-Binding Proteins / physiology*
-
Fas-Associated Death Domain Protein
-
Hepatocytes / enzymology*
-
Hepatocytes / immunology
-
Hepatocytes / metabolism
-
Hepatocytes / pathology
-
Humans
-
Immune Sera / administration & dosage
-
Injections, Intravenous
-
Interferon Regulatory Factor-1
-
Interferon-gamma / antagonists & inhibitors
-
Interferon-gamma / immunology
-
Interferon-gamma / physiology*
-
Intracellular Fluid / enzymology*
-
Intracellular Fluid / immunology
-
JNK Mitogen-Activated Protein Kinases
-
Leukocyte Common Antigens / biosynthesis
-
Liver Failure / enzymology*
-
Liver Failure / immunology*
-
Liver Failure / pathology
-
Liver Failure / prevention & control
-
Male
-
Mice
-
Mice, Inbred BALB C
-
Mitogen-Activated Protein Kinases / physiology*
-
NF-kappa B / metabolism
-
Phosphoproteins / antagonists & inhibitors
-
Phosphoproteins / metabolism
-
Phosphoproteins / physiology*
-
STAT1 Transcription Factor
-
Signal Transduction / immunology
-
Trans-Activators / antagonists & inhibitors
-
Trans-Activators / metabolism
-
Tumor Cells, Cultured
-
Tumor Necrosis Factor-alpha / pharmacology
-
fas Receptor / metabolism
Substances
-
Adaptor Proteins, Signal Transducing
-
Carrier Proteins
-
DNA-Binding Proteins
-
FADD protein, human
-
Fadd protein, mouse
-
Fas-Associated Death Domain Protein
-
IRF1 protein, human
-
Immune Sera
-
Interferon Regulatory Factor-1
-
Irf1 protein, mouse
-
NF-kappa B
-
Phosphoproteins
-
STAT1 Transcription Factor
-
STAT1 protein, human
-
Stat1 protein, mouse
-
Trans-Activators
-
Tumor Necrosis Factor-alpha
-
fas Receptor
-
Concanavalin A
-
Interferon-gamma
-
JNK Mitogen-Activated Protein Kinases
-
Mitogen-Activated Protein Kinases
-
Leukocyte Common Antigens