HEPATITIS B VIRUS QUASISPECIES EVOLUTION AND HBEAG - NEGATIVE VIRAL REACTIVATION

Abstract

AIMS: TO EXAMINE THE VIRAL EVOLUTION PATTERNS IN HBEAG-NEGATIVE REACTIVATION PATIENTS AND INVESTIGATE WHETHER MUTATIONS COULD LEAD TO CHANGES IN HBV REPLICATION. METHODS: PATIENTS WERE ANALYSED FOR THEIR EVOLUTION PATTERNS. FULL-LENGTH HBV DNAS WERE TRANSFECTED INTO HUH7 CELLS FOR FUNCTIONAL ANALYSIS OF THEIR REPLICATION FITNESS. POINT MUTATIONS IDENTIFIED IN PROMOTER/ENHANCER REGIONS WERE ANALYSED USING SITE-DIRECTED MUTAGENESIS. RESULTS: VIRAL GENETIC DIVERSITY AND EVOLUTION RATES OF REACTIVATION PATIENTS WERE NOT STATISTICALLY DIFFERENT FROM INACTIVE CONTROLS. IN TRANSFECTED CELLS, HBV CLONES ISOLATED DURING REACTIVATION SHOWED HIGHER HBV PRODUCTION THAN THE CLONES ISOLATED BEFORE REACTIVATION. MUTATIONS OF HNF-3 BINDING SITES IN CORE PROMOTER/ENHANCERII AND X PROMOTER/ENHANCERI REGIONS WERE DEMONSTRATED TO ACCOUNT FOR SOME OF THE CHANGES IN HBV REPLICATION. CONCLUSIONS: GENETIC DIVERSITY AND EVOLUTION RATES OF REACTIVATION PATIENTS WERE SIMILAR TO INACTIVE CONTROLS. HOWEVER, RE