HBV HBV T1719G mutation reduced HBV HBV replication through mutant Enh II II and HB HB x protein in vitro

摘要

Summary It was repeatedly reported that the hepatitis B virus ( HBV ) T1719G mutation was very common and related to progression and malignancy of liver disease. However, its effect on viral replication efficiency remains unclear. In this study, we aimed to evaluate the function and mechanisms of the T1719G mutation on viral replication capacity. Wild‐type and T1719G mutation‐bearing HBV 1.2× plasmids were transfected into Huh7 and HepG2 cells, respectively, and HBV total RNA , 3.5?kb RNA and supernatant HBV DNA were assessed using real‐time PCR , hepatitis B surface antigen ( HB sAg) and hepatitis B e antigen ( HB eAg) levels were measured by time‐resolved fluoroimmunoassay. In order to assess Enh II activity and the binding capacity of HNF 3β to Enh II sequence, dual‐luciferase assay and Chromatin immunoprecipitation (Ch IP )‐ PCR were employed, respectively. Simultaneously, the HB x or HB x‐mut (T1719G) plasmid was co‐transfected to evaluate the effect of HB x on viral replication. Our results showed that the T1719G mutation impaired viral replication efficacy compared with the wild type both by reducing Enh II activity and binding capacity of HNF 3β with Enh II . And such reduction caused by T1719G mutation could be rescued by HB x protein. Our results show that the T1719G mutation decreases HBV viral replication capacity possibly by mutant HB x protein and altered Enh II activity.