title: Immunoregulation of hepatitis B virus infection--rationale and clinical application.
abstract: Hepatitis B virus (HBV) is susceptible to the cellular immune responses, especially to the signal of interferon (IFN)-gamma. The action of IFN-gamma is pleiotropic, and causes downregulation of HBV in protein, RNA, and possibly DNA levels. Therefore, therapeutic vaccination to induce cellular immune responses to HBV is a promising approach for controlling chronic HBV infection. A number of clinical trials with this approach have been conducted to date, however, they have not been as successful as initially expected. T-cell exhaustion induced by the excessive HBV antigens caused by persistent infection is thought to be one of the main causes of poor responses to therapeutic vaccination. In this review, the mechanisms behind immunoregulation of HBV replication and immunodysfunction during chronic HBV infection are summarized, and novel approaches to improve the efficacy of therapeutic vaccination, from basic research to clinical trials, are introduced.
authors.affiliation: Division of Pathophysiological Laboratory Sciences, Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Japan. ishikawa@met.nagoya-u.ac.jp
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Ishikawa
mesh_terms: D000818:Animals; D006509:Hepatitis B / Q000188:drug therapy / Q000276:immunology* / Q000378:metabolism / Q000517:prevention & control; D017325:Hepatitis B Vaccines / Q000627:therapeutic use; D006515:Hepatitis B virus / Q000187:drug effects / Q000276:immunology* / Q000472:pathogenicity; D006801:Humans; D007371:Interferon-gamma / Q000627:therapeutic use; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D017325:Hepatitis B Vaccines; D007371:Interferon-gamma