title: Inhibitory effect of the combination of CpG-induced cytokines with lamivudine against hepatitis B virus replication in vitro.
abstract: BACKGROUND
  Currently approved antiviral monotherapies against chronic hepatitis B fail to eradicate hepatitis B virus (HBV), to overcome the defects in HBV-specific immune responses and to prevent HBV relapse after cessation of therapy. CpG oligodesoxynucleotides (CpG ODN) are synthetic agonists of Toll-like receptor 9 and potent inducers of innate and acquired immunity. Our aim was to establish the proof of concept of the antiviral benefit of combining a nucleoside analogue with CpG-induced cytokines on HBV replication in vitro.
  
  
  METHODS
  Peripheral blood mononuclear cells from HBV-negative individuals were stimulated with CpG ODN to generate CpG-induced cytokine supernatants. Proliferating HepaRG and HepG2 cells were transduced with recombinant HBV baculovirus and differentiated HepaRG cells were inoculated with HBV virions. Antiviral effects of CpG-induced cytokine with or without lamivudine were evaluated by analysing HBV DNA, HBV RNA and antigen secretion (hepatitis B surface antigen [HBsAg] and hepatitis B e antigen [HBeAg]).
  
  
  RESULTS
  Following transduction or HBV inoculation, CpG-induced cytokines strongly inhibited HBV viral intermediates of replication, as well as HBsAg and HBeAg secretion from infected cells. Strikingly, in transduced HepaRG cells, the combination of CpG-induced cytokines with lamivudine reduced the 50% effective concentration of lamivudine by 100-fold. Importantly, the treatment of CpG-induced cytokines prior to HBV inoculation conferred a partial protection against infection to hepatocytes.
  
  
  CONCLUSIONS
  CpG-induced cytokines associated with polymerase inhibitors represent a promising combination to suppress HBV replication. Such an immunotherapeutic strategy should be evaluated in vivo to assess restoration and duration of anti-HBV-specific immune responses.
authors.affiliation: INSERM U871, Lyon, France.
authors.forename: Isabelle E
authors.initials: IE
authors.lastname: Vincent
authors.forename: Julie
authors.initials: J
authors.lastname: Lucifora
authors.forename: David
authors.initials: D
authors.lastname: Durantel
authors.forename: Olivier
authors.initials: O
authors.lastname: Hantz
authors.forename: Isabelle
authors.initials: I
authors.lastname: Chemin
authors.forename: Fabien
authors.initials: F
authors.lastname: Zoulim
authors.forename: Christian
authors.initials: C
authors.lastname: Trepo