| Virus Name | Hepatitis B virus |
| Virus Short Name | HBV |
| Order | Unassigned |
| Virus Family | Hepadnaviridae |
| Virus Subfamily | N.A. |
| Genus | Orthohepadnavirus |
| Species | Hepatitis B virus |
| Host | Human, mammals |
| Cell Tropism | Hepatocytes |
| Associated Disease | Hepatitis, hepatocellular carcinoma(chronic infections), cirrhosis |
| Mode of Transmission | Sexual contact, blood, maternal-neonatal |
| VIPR DB link | N.A. |
| ICTV DB link | https://talk.ictvonline.org/ictv-reports/ictv_9th_report/reverse-transcribing-dna-and-rna-viruses-2011/w/rt_viruses/155/hepadnaviridae |
| Virus Host DB link | N.A. |
| Paper Title | The Hepatitis B Virus (HBV) HBx protein activates AKT To simultaneously regulate HBV replication and hepatocyte survival |
| Author's Name | Siddhartha Rawat, Michael J. Bouchard |
| Journal Name | Journal Of Virology |
| Pubmed ID | 25355887 |
| Abstract | Chronic infection with hepatitis B virus (HBV) is a risk factor for developing liver diseases such as hepatocellular carcinoma (HCC). HBx is a multifunctional protein encoded by the HBV genome HBx stimulates HBV replication and is thought to play an important role in the development of HBV-associated HCC. HBx can activate the phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway in some cell lines however, whether HBx regulates PI3K/AKT signaling in normal hepatocytes has not been evaluated. In studies described here, we assessed HBx activation of PI3K/AKT signaling in an ex vivo model of cultured primary hepatocytes and determined how this HBx activity affects HBV replication. We report that HBx activates AKT in primary hepatocytes and that the activation of AKT decreases HBV replication and HBV mRNA and core protein levels. We show that the transcription factor hepatocyte nuclear factor 4alpha (HNF4alpha) is a target of HBx-regulated AKT, and we link HNF4alpha to HBx-regulated AKT modulation of HBV transcription and replication. Although we and others have shown that HBx stimulates and is likely required for HBV replication, we now report that HBx also activates signals that can diminish the overall level of HBV replication. While this may seem counterintuitive, we show that an important effect of HBx activation of AKT is inhibition of apoptosis. Consequently, our studies suggest that HBx balances HBV replication and cell survival by stimulating signaling pathways that enhance hepatocyte survival at the expense of higher levels of HBV replication. |
| Used Model | Primary rat hepatocyte cells |
| DOI | 10.1128/JVI.02440-14 |
