Chronic Hepatitis B Genotype C Mouse Model with Persistent Covalently Closed Circular DNA

Area of Science:

• Hepatology
• Virology
• Molecular Biology

Background:

• Chronic Hepatitis B virus (HBV) infection poses significant mortality risks due to cirrhosis and hepatocellular carcinoma (HCC).
• Covalently closed circular DNA (cccDNA) is a persistent viral DNA reservoir in hepatocytes, driving continuous HBV replication and treatment resistance.
• Existing animal models inadequately replicate cccDNA dynamics, hindering research into HBV pathogenesis and therapeutics.

Purpose of the Study:

• To develop and validate a novel mouse model for investigating Hepatitis B virus cccDNA formation and maintenance.
• To establish a platform for evaluating therapeutic strategies targeting the HBV cccDNA reservoir.

Main Methods:

• Infection of C57BL/6 mice with recombinant adeno-associated virus (rAAV) carrying a 1.3-overlength HBV genome (genotype C).
• Assessment of cccDNA levels and viral replication markers (HBsAg, HBeAg, HBV DNA) at various time points.
• Quantitative PCR (qPCR) with selective DNase treatment and Southern blot analysis for cccDNA detection.

Main Results:

• Successful establishment of a chronic HBV mouse model with persistent cccDNA expression in hepatocytes.
• Sustained elevation of serum HBsAg and HBeAg for up to 12 weeks with normal alanine transaminase (ALT) levels.
• Confirmation of HBV DNA expression and detection of cccDNA using qPCR and Southern blot analysis.

Conclusions:

• The rAAV-HBV1.3 mouse model effectively recapitulates key aspects of chronic HBV infection, including cccDNA persistence.
• This model serves as a valuable tool for studying long-term cccDNA maintenance and for preclinical testing of novel anti-HBV therapies targeting cccDNA.