Viral-load-dependent effects of liver injury and regeneration on hepatitis B virus replication in mice.
Hepatitis B virus (HBV) is a hepatotropic virus that can cause severe liver diseases. By conducting studies using four different transgenic mouse lines that carry either the wild-type HBV genome or the HBV genome incapable of expressing the X gene, we found that liver injury and regeneration induced by a partial hepatectomy (PHx) could have different effects on HBV replication depending on the mouse lines. Further studies using hydrodynamic injection to introduce different amounts of the HBV genomic DNA into the mouse liver revealed that liver injury and regeneration induced by PHx enhanced HBV replication when viral load was low and suppressed HBV replication when viral load was high. These effects of liver injury and regeneration on HBV were independent of the HBV X protein and apparently due to alpha and beta interferons (IFN-α/β), as the effects could be abolished by the injection of anti-IFN-α/β antibodies. Further analysis indicated that PHx could induce the expression of hepatocyte nuclear factor 3 gamma (HNF3γ) when viral load was low and activate the signal transducer and activator of transcription 3 (Stat3) and suppress the expression of the suppressor of cytokine signaling 3 (SOCS3) irrespective of viral load. As both HNF3γ and Stat3 are required to activate the HBV enhancer I to stimulate HBV gene expression and replication, these results provided an explanation to the viral-load-dependent effect of liver injury and regeneration on HBV replication. Our studies thus revealed a novel interaction between HBV and its host and provided important information for understanding HBV replication and pathogenesis during liver injury.
Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
Yongjun
Y
Tian
Wen-ling
WL
Chen
Cheng-fu
CF
Kuo
Jing-hsiung James
JH
Ou
D000818:Animals; D001483:Base Sequence; D004279:DNA, Viral / Q000097:blood / Q000235:genetics; D006498:Hepatectomy; D006515:Hepatitis B virus / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D051543:Hepatocyte Nuclear Factor 3-gamma / Q000378:metabolism; D054884:Host-Pathogen Interactions / Q000502:physiology; D016898:Interferon-alpha / Q000037:antagonists & inhibitors / Q000502:physiology; D016899:Interferon-beta / Q000037:antagonists & inhibitors / Q000502:physiology; D008099:Liver / Q000293:injuries / Q000503:physiopathology / Q000821:virology*; D008115:Liver Regeneration / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D050796:STAT3 Transcription Factor / Q000378:metabolism; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics / Q000502:physiology; D019562:Viral Load; D054334:Viral Regulatory and Accessory Proteins; D014779:Virus Replication
D004279:DNA, Viral; C496506:Foxa3 protein, mouse; D016898:Interferon-alpha; D050796:STAT3 Transcription Factor; C491411:Socs3 protein, mouse; C494087:Stat3 protein, mouse; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins; D015534:Trans-Activators; D054334:Viral Regulatory and Accessory Proteins; C057628:hepatitis B virus X protein; D051543:Hepatocyte Nuclear Factor 3-gamma; D016899:Interferon-beta