In the human hepatoma cell line Huh7, the coexpression of the coactivators peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α), cyclic AMP-responsive element binding protein binding protein (CBP), steroid receptor coactivator 1 (SRC1), and protein arginine methyltransferase 1 (PRMT1) only modestly increase hepatitis B virus (HBV) biosynthesis. However, by utilizing the human embryonic kidney cell line HEK293T, it was possible to demonstrate that PGC1α alone can support viral biosynthesis independently of the expression of additional coactivators or transcription factors. In contrast, additional coactivators failed to support robust HBV replication in the absence of PGC1α. These observations indicate that PGC1α represents a novel adaptor molecule capable of recruiting the necessary transcriptional machinery to the HBV nucleocapsid promoter to modestly enhance viral pregenomic 3.5-kb RNA synthesis. Although this change in transcription is associated with a similar modest change in hepatitis B virus core antigen polypeptide (HBcAg/p21) synthesis, it mediates a dramatic increase in viral capsid production and robust viral replication. Therefore, it is apparent that the synthesis of cytoplasmic HBcAg/p21 above a critical threshold level is required for the efficient assembly of HBV replication-competent viral capsids. Hepatitis B virus (HBV) is a major human pathogen, and novel targets for the development of additional therapeutic agents are urgently needed. Here we demonstrate that the coactivator peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) serves as a unique adaptor molecule for the recruitment of additional coactivator proteins, which can finely regulate HBV transcription. The consequence of this precise regulation of viral RNA levels by PGC1α is a subtle increase in cytoplasmic HBcAg/p21 polypeptide translation, which shifts the equilibrium from dimer formation dramatically in favor of viral capsid assembly. These findings suggest that both PGC1α and capsid assembly may represent attractive targets for the development of antiviral agents against chronic HBV infection.

No abstract

OBJECTIVE The purpose of this study was to evaluate the relationship of IL28B rs12979860 and rs8099917 polymorphisms with the clinical, histological, and virological outcomes of patients with chronic hepatitis B (CHB) also the treatment responses of patients who received Nucleos(t)ide analogs (NAs) therapy. METHODS This study included 152 CHB patients who were underwent liver parenchymal biopsy. The IL28B rs12979860 and rs8099917 polymorphism were genotyped using the TaqMan assay. RESULTS The IL28B rs12979860 CC and IL28B rs8099917 TT were identified as the genotypes with the highest frequency in all patients. On the other hand, IL28B rs12979860 TT and IL28B rs8099917 GG were the genotypes with the lowest frequency. The frequency of IL28B rs8099917 TG genotype was significantly different between patients with hepatitis B, who has histologically defined liver cirrhosis and no-fibrosis (p=0.02). In addition, a statistically significant correlation was found between the presence of IL28B rs8099917 G allele and virological unresponsiveness to NAs treatments in CHB patients (p=0.028). CONCLUSION The presence of the IL28B rs8099917 G allele in CHB patients might be associated with the risk of developing cirrhosis and virological unresponsiveness to NAs treatments.

No abstract

No abstract