Sequence-specific inhibition of duck hepatitis B virus reverse transcription by peptide nucleic acids (PNA).
OBJECTIVE
Peptide nucleic acids (PNAs) appear as promising new antisense agents, that have not yet been examined as hepatitis B virus (HBV) inhibitors. Our aim was to study the ability of PNAs targeting the duck HBV (DHBV) encapsidation signal epsilon to inhibit reverse transcription (RT) and to compare their efficacy with phosphorothioate oligodeoxynucleotides (S-ODNs).


METHODS
The effect of two partly overlapping PNAs targeting epsilon and of analogous S-ODNs was tested in cell-free transcription and translation system for DHBV RT expression. In addition their antiviral effect was investigated in primary duck hepatocytes (PDH).


RESULTS
Both PNAs reproducibly inhibited DHBV RT in a dose-dependent manner with IC(50) of 10nM, whereas up to 600-fold higher concentration of S-ODNs was required for similar inhibition. The PNA targeting the bulge and upper stem of epsilon appeared as more efficient RT inhibitor than the PNA targeting only the bulge. Importantly, the inhibition was highly sequence-specific since double-mismatched PNA had no effect on the RT reaction. Moreover, in PDH the PNA coupled to Arg(7) cationic delivery peptide decreased DHBV replication.


CONCLUSIONS
We provide the first evidence that PNAs targeting the bulge and upper stem of epsilon can efficiently and in a sequence-specific manner inhibit DHBV RT.
Robaczewska
Magdalena
M
INSERM U271, 151 Cours Albert Thomas, F-69424 Lyon Cedex 03, France.
Narayan
Ramamurthy
R
Seigneres
Beatrice
B
Schorr
Olivier
O
Thermet
Alexandre
A
Podhajska
Anna J
AJ
Trepo
Christian
C
Zoulim
Fabien
F
Nielsen
Peter E
PE
Cova
Lucyna
L
D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D004372:Ducks; D004625:Embryo, Nonmammalian; D015611:Hepatitis B Virus, Duck / Q000201:enzymology / Q000235:genetics*; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000494:pharmacology; D020135:Peptide Nucleic Acids / Q000494:pharmacology*; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism*; D048348:Reverse Transcription / Q000235:genetics*
D017931:DNA Primers; D009838:Oligodeoxyribonucleotides; D020135:Peptide Nucleic Acids; D012194:RNA-Directed DNA Polymerase