Article Virology

Chinese Science Bulletin

, Volume 58, Issue 15, pp 1760-1766

Open Access This content is freely available online to anyone, anywhere at any time.

Polymerase mutations rtN238R, rtT240Y and rtN248H of hepatitis B virus decrease susceptibility to adefovir

  • Bo QinAffiliated withState Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of SciencesShaoxing Centre for Disease Control and PreventionInstitute of Virology, University Hospital of Essen
  • , RongJuan PeiAffiliated withState Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences
  • , TingTing HeAffiliated withShaoxing Centre for Disease Control and Prevention
  • , ZhaoHui HuangAffiliated withShaoxing Centre for Disease Control and Prevention
  • , GuoShao PanAffiliated withShaoxing Centre for Disease Control and Prevention
  • , ChunYu TuAffiliated withShaoxing Centre for Disease Control and Prevention
  • , MengJi LuAffiliated withState Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of SciencesInstitute of Virology, University Hospital of Essen
  • , XinWen ChenAffiliated withState Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences Email author 

Abstract

Long term antiviral therapy with nucleos(t)ide analogs (NAs) may lead to the emergence of drug-resistance viral mutants in chronic hepatitis B virus (HBV) patient. The purpose of this study was to identify adefovir dipivoxil (ADV) resistance mutations of HBV polymerase and determine effective drugs to replace ADV. The reverse transcriptase (RT) coding region was PCR-amplified using HBV DNA extracted from patient blood samples and sequenced. Nineteen substitution mutations were detected. Among them, rtN238R, rtT240Y and rtN248H were often observed in patients receiving ADV administration. These three potential drug resistant sites were introduced into HBV replication-competent plasmids. The in vitro susceptibility of both wild-type (WT) and mutant-type (MT) HBV to NAs was analyzed by Southern blotting and quantitative real-time PCR. The rtN238R, rtT240Y and rtN248H substitutions had no obvious effect on HBV DNA replication or gene expression. The in vitro susceptibility analysis showed that rtN238R, rtT240Y and rtN248H substitutions were responsible for the reduced susceptibility to ADV, and demonstrated a 5.42-, 2.89- and 5.72-fold increase in resistance towards ADV, respectively. However, HBV harbored these mutations retained normal susceptibility to LMV, LdT, ETV and TDF.

Keywords

hepatitis B virus resistance mutation adefovir dipivoxil (ADV)