Medicina Molecular e Genética

The Effect and Possible Mechanism of Double-Stranded DNA on Replication of Hepatitis B Virus

Abstract

Yan Yang, Anding Liu, Shenpei Liu, Chunyan Zhang, Xiang Liu, Hongping Huang, Jingjiao Song, Yan Chen, Yuan Yu and Xuefeng Zhou

Liver is one of the target organs for double-stranded DNA (dsDNA)-vector mediated gene delivery due to the highly efficient uptake of gene therapy vectors. Recently dsDNA was described as a pathogen associated molecular pattern that could be recognized by intracellular DNA sensors. Herein, we explored the possibility that dsDNA may change the intracellular innate immune responses of hepatocyte-derived cell and therefore regulate the replication of hepatitis B virus (HBV). A hepatoma cell line HepG2.2.15 which derived from HepG2 with integrated HBV genome, were treated with poly (dA-dT), a synthetic double-stranded DNA molecule. Unexpectedly, HBV replication was up-regulated after poly (dA-dT) transfection in HepG2.2.15 despite the delayed activation of ISGs. There was no nuclear-plasma translocation of IRF3 or NF-κB observed at a early stage. Treatment of HepG2.2.15 cells with supernatant harvested from the cells transfected with poly (dA-dT) indicating that poly (dA-dT) -enhanced HBV replication was predominantly mediated by not secreted cytokines, but intracellular factors. By blocking the cellular signal pathways with inhibitors, we found that U0126, an inhibitor of ERK1/2, could abolish the poly (dA-dT) enhanced HBV replication. Pathway-scan results also indicated that phosphorylated MEK1/2 was enhanced after poly (dA-dT) transfection. Whether this HBV replicating enhancement is good for HBV infection disease outcome needs to be further investigated.