The flavonoid ellagic acid from a medicinal herb inhibits host immune tolerance induced by the hepatitis B virus-e antigen.

Abstract

The aim of this study is to characterize the role of ellagic acid, a flavonoid from a medicinal herb which blocks HBeAg secretion in a HBV infected cell line and in HBeAg transgenic mice, in immune tolerance in chronic HBV infection. Using the mouse strain C57ML/6, HBeAg-producing transgenic mice (HBeAg-Tg), under the control of metal ion-inducible promoter were generated. The effect on immune tolerance of HBeAg-Tg and the release of immune tolerance by the inhibitor of HBeAg secretion, ellagic acid, was tested using T/B cell proliferation, HBeAg/HBeAb production, cytotoxic T-lymphocyte (CTL) and cytokine assays. C57ML/6 based HBeAg-producing HBeAg-Tg mice were tolerant to HBeAg at the T and B-cell level, did not produce antibodies to HBeAg in vivo and in vitro, produced minimal levels of cytokines (IL-4 and IFN-gamma) and decreased CTL responses, while feeding mice with ellagic acid (5mg/kg body weight) blocked the immune tolerance caused by HBeAg. Our results suggest that host immune tolerance induced by HBeAg during HBV infection, a viral strategy to guarantee HBV infection, can be overcome by ellagic acid, thus it can be used as a therapeutic for HBV-carriers.

• Authors: Eun Hwa Kang, Tae Young Kown, Goo Taeg Oh, Weung Feel Park, Sung-Il Park, Sung Kyu Park, Young Ik Lee
• Journal: Antiviral research (Antiviral Res) Vol. 72 Issue 2 Pg. 100-6 (Nov 2006) ISSN: 0166-3542 [Print] Netherlands
• PMID: 16720052 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Hepatitis B Antibodies
• Hepatitis B e Antigens
• Immunologic Factors
• Ellagic Acid
• Interleukin-4
• Interferon-gamma

Topics

• Animals
• B-Lymphocytes (immunology)
• Cells, Cultured
• Cytotoxicity Tests, Immunologic
• Ellagic Acid (administration & dosage, pharmacology)
• Hepatitis B Antibodies (biosynthesis, blood)
• Hepatitis B e Antigens (immunology)
• Hepatitis B virus (immunology)
• Immune Tolerance (drug effects)
• Immunologic Factors (pharmacology)
• Interferon-gamma (biosynthesis)
• Interleukin-4 (biosynthesis)
• Lymphocyte Activation
• Mice
• Mice, Transgenic
• Plants, Medicinal
• T-Lymphocytes (immunology)
• T-Lymphocytes, Cytotoxic (immunology)