A nucleosome switch primes hepatitis B virus infection

Area of Science:

• Hepatology
• Virology
• Molecular Biology

Background:

• Chronic hepatitis B virus (HBV) infection is a leading cause of liver disease and hepatocellular carcinoma.
• HBV establishes an episomal minichromosome (cccDNA) upon infection, requiring viral X gene expression to overcome host silencing.
• The interplay between cccDNA chromatin structure and X gene transcription remains unclear.

Purpose of the Study:

• To investigate the role of cccDNA chromatinization in regulating HBV X gene transcription.
• To explore potential therapeutic strategies targeting cccDNA structure for HBV treatment.

Main Methods:

• Development of a reconstituted HBV minichromosome platform.
• In situ validation of findings in primary human hepatocytes.
• Assessment of the impact of the chromatin-destabilizing molecule CBL137.

Main Results:

• Nucleosome occupancy on the HBV cccDNA minichromosome was found to regulate X gene transcription.
• The chromatin-destabilizing agent CBL137 effectively inhibited full-length X transcription.
• CBL137 demonstrated inhibition of HBV infection in primary human hepatocytes.

Conclusions:

• cccDNA chromatin structure is a critical regulator of HBV X gene expression.
• Targeting cccDNA chromatin offers a promising therapeutic avenue for chronic HBV infection.
• Inhibition of X gene transcription via chromatin modulation presents a novel strategy against HBV.