Characterization of resistance to non-obligate chain-terminating ribonucleoside analogs that inhibit hepatitis C virus replication in vitro.
The urgent need for efficacious drugs to treat chronic hepatitis C virus (HCV) infection requires a concerted effort to develop inhibitors specific for virally encoded enzymes. We demonstrate that 2'-C-methyl ribonucleosides are efficient chain-terminating inhibitors of HCV genome replication. Characterization of drug-resistant HCV replicons defined a single S282T mutation within the active site of the viral polymerase that conferred loss of sensitivity to structurally related compounds in both replicon and isolated polymerase assays. Biochemical analyses demonstrated that resistance at the level of the enzyme results from a combination of reduced affinity of the mutant polymerase for the drug and an increased ability to extend the incorporated nucleoside analog. Importantly, the combination of these agents with interferon-alpha results in synergistic inhibition of HCV genome replication in cell culture. Furthermore, 2'-C-methyl-substituted ribonucleosides also inhibited replication of genetically related viruses such as bovine diarrhea virus, yellow fever, and West African Nile viruses. These observations, together with the finding that 2'-C-methyl-guanosine in particular has a favorable pharmacological profile, suggest that this class of compounds may have broad utility in the treatment of HCV and other flavivirus infections.
Migliaccio
Giovanni
G
Department of Biochemistry, Istituto di Ricerche di Biologia Molecolare P. Angeletti (IRBM), 00040 Pomezia, Italy.
Tomassini
Joanne E
JE
Carroll
Steven S
SS
Tomei
Licia
L
Altamura
Sergio
S
Bhat
Balkrishen
B
Bartholomew
Linda
L
Bosserman
Michele R
MR
Ceccacci
Alessandra
A
Colwell
Lawrence F
LF
Cortese
Riccardo
R
De Francesco
Raffaele
R
Eldrup
Anne B
AB
Getty
Krista L
KL
Hou
Xiaoli S
XS
LaFemina
Robert L
RL
Ludmerer
Steven W
SW
MacCoss
Malcolm
M
McMasters
Daniel R
DR
Stahlhut
Mark W
MW
Olsen
David B
DB
Hazuda
Daria J
DJ
Flores
Osvaldo A
OA
D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D002460:Cell Line; D024882:Drug Resistance, Viral; D016174:Hepacivirus / Q000502:physiology*; D008297:Male; D015394:Molecular Structure; D051381:Rats; D017207:Rats, Sprague-Dawley; D012263:Ribonucleosides / Q000737:chemistry / Q000494:pharmacology*; D014779:Virus Replication / Q000187:drug effects*
D000998:Antiviral Agents; D012263:Ribonucleosides