Identification of Antiviral Host Factors by Functional Gene Expression Analysis using HBV Infection Assay Systems

The in vitro HBV infection assay system was established in primary human hepatocytes (PXB cells) infected with HBV derived from the plasmid containing 1.3-mer HBV genome. Comprehensive and functional studies were performed by small interfering RNA knockdown and vector transfection experiments of the related genes and analyzed using microarray to reveal the host factors related to HBV regulation. Knockdown of STAT1 increased viral products in HBV-transfected HepG2 cells, but unexpectedly decreased in HBV-infected PXB cells. In RNA microarray analysis, STAT1 knockdown induced changes in intracellular molecules related to metabolism and protein synthesis in PXB cells, but not in HepG2 cells. RNA microarray was performed in HBV-infected PXB cells and HepG2.D11 cells with STAT1 knockdown and HBV-infected PXB cells with IRF2 knockdown. siRNA was transfected into the PXB cells on day 0 and HBV was added on day 4 and PXB cells were collected on day 13. HepG2.D11 cells were seeded on day 0 and siRNA was transfected at medium change on day 1. HepG2.D11 cells were collected on day 5. The comparison combinations used in this analysis were 1) PXB_si-Non Target and PXB_si-STAT1, 2) HepG2_si-Non Target and HepG2_si-STAT1, and 3) PXB_si-Non Target (PXB Non E077) and PXB_si-IRF2 (PXB IRF2 E077).