Induction of intercellular adhesion molecule-1 (CD54) on human hepatoma cell line HepG2: influence of cytokines and hepatitis B virus-DNA transfection.
Human hepatocyte expression of intercellular adhesion molecule-1 (ICAM-1) (CD54) was studied in vitro by exposing the well differentiated human hepatoblastoma cell line HepG2 to various cytokines. In addition, hepatitis B virus (HBV)-DNA transfected HepG2 cells were also analysed. Expression of ICAM-1 on HepG2 cells was then revealed with an immunohistochemical procedure. Untreated HepG2 cells were unreactive, but showed strong cytoplasmic ICAM-1 immunoreactivity after treatment with interferon-gamma (IFN-gamma). This induction was completely inhibited by addition of a neutralizing antibody directed to IFN-gamma. IL-1, IL-6, tumour necrosis factor-alpha (TNF-alpha) and IFN-alpha, used alone or in combination, did not induce ICAM-1 expression, neither did they inhibit the IFN-gamma-induced expression of this adhesion molecule on HepG2 cells. Untreated hepatitis B virus-DNA transfected HepG2 cells expressed membranous ICAM-1. These results indicate that IFN-gamma is the main cytokine trigger for ICAM-1 expression on HepG2 cells, suggesting that in areas of liver inflammation this adhesion molecule is up-regulated on hepatocytes by locally released IFN-gamma. In addition, expression of ICAM-1 by hepatitis B virus-DNA transfected HepG2 cells suggests other, still unknown, triggering mechanisms in the induction of such adhesion molecules, for instance gene activation by viral genome, or autocrine virus-induced hepatocellular cytokine production.
Department of Pathology, University Hospital Sint-Rafaël, Leuven, Belgium.
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R
Volpes
J J
JJ
van den Oord
V J
VJ
Desmet
S H
SH
Yap
D006528:Carcinoma, Hepatocellular / Q000378:metabolism*; D015815:Cell Adhesion Molecules / Q000096:biosynthesis*; D016207:Cytokines / Q000494:pharmacology*; D004279:DNA, Viral; D006515:Hepatitis B virus / Q000235:genetics*; D006801:Humans; D018799:Intercellular Adhesion Molecule-1; D007371:Interferon-gamma / Q000494:pharmacology; D008113:Liver Neoplasms / Q000378:metabolism*; D014162:Transfection; D014407:Tumor Cells, Cultured
D015815:Cell Adhesion Molecules; D016207:Cytokines; D004279:DNA, Viral; D018799:Intercellular Adhesion Molecule-1; D007371:Interferon-gamma