Antiviral resistance mutations potentiate hepatitis B virus immune evasion through disruption of its surface antigen a determinant

Antivir Ther. 2008;13(3):439-47.


Background: The hepatitis B virus (HBV) pol gene overlaps the S gene encoding surface antigen (HBsAg). It has been reported previously that drug-induced changes in HBsAg alter its binding to sera from humans immunized against HBV. We investigate here the changes to specific epitopes in the a determinant (the major target of neutralizing antibody) caused by a number of drug-resistant mutations.

Methods: Recombinant HBsAgs, produced by transfection of Chinese hamster ovary cells with S gene plasmids into which lamivudine, adefovir and entecavir resistance and common antibody-escape mutations had been introduced, were probed with monoclonal antibodies to epitopes in the first and second loops of the a determinant.

Results: The mutations rtF166L/sF158Y (lamivudine-associated, compensatory) and rtl169T/sF161L (entecavir-associated, primary) acting alone, and the mutations rtV173L/sE164D (lamivudine-associated, compensatory) and rtSilent/sD144E (antibody escape-associated) each when combined with rtM204V/sl195M (lamivudine-associated, primary) led to decreases in antibody reactivity to epitopes in the first or second loop, or in both loops. The rtM204V/sl195M + rtV173L/sE164D mutations yielded an epitope-antibody profile similar to the rtR153Q/sG145R vaccine escape mutant. The rtM204V/sl195M mutation combined with the rtF166L/sF158Y or rtR153Q/sG145R mutation restored reactivity to second-loop epitopes previously abrogated by single mutations.

Conclusions: Mutations associated with resistance to nucleos(t)ide analogue therapy, singly or in combination with each other or antibody escape-associated mutations, alter HBsAg immunoreactivity through concomitant amino acid substitutions at codons within and downstream of the a determinant. The findings have implications for understanding the native structure of HBsAg, optimizing treatment of chronic hepatitis B and evaluating the success of immunization programmes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenine / analogs & derivatives
  • Adenine / pharmacology
  • Animals
  • Antibodies, Monoclonal / immunology
  • Antigen-Antibody Reactions
  • Antiviral Agents / pharmacology
  • CHO Cells
  • Cricetinae
  • Cricetulus
  • Drug Resistance, Multiple, Viral / genetics*
  • Enzyme-Linked Immunosorbent Assay
  • Epitope Mapping
  • Gene Expression Regulation, Enzymologic
  • Gene Expression Regulation, Viral* / drug effects
  • Gene Products, pol / genetics*
  • Guanine / analogs & derivatives
  • Guanine / pharmacology
  • Hepatitis B Antibodies / immunology*
  • Hepatitis B Surface Antigens / genetics*
  • Hepatitis B Surface Antigens / immunology
  • Hepatitis B virus / drug effects
  • Hepatitis B virus / enzymology
  • Hepatitis B virus / genetics*
  • Hepatitis B virus / immunology
  • Humans
  • Immunodominant Epitopes / genetics*
  • Lamivudine / pharmacology
  • Mutagenesis, Site-Directed
  • Mutation*
  • Organophosphonates / pharmacology
  • Transfection


  • Antibodies, Monoclonal
  • Antiviral Agents
  • Gene Products, pol
  • Hepatitis B Antibodies
  • Hepatitis B Surface Antigens
  • Immunodominant Epitopes
  • Organophosphonates
  • P protein, Hepatitis B virus
  • Lamivudine
  • entecavir
  • Guanine
  • adefovir
  • Adenine