A replicon-based shuttle vector system for assessing the phenotype of HCV NS5B polymerase genes isolated from patient populations.
Middleton T,
He Y,
Pilot-Matias T,
Tripathi R,
Lim BH,
Roth A,
Chen CM,
Koev G,
Ng TI,
Krishnan P,
Pithawalla R,
Mondal R,
Dekhtyar T,
Lu L,
Mo H,
Kati WM,
Molla A.
Abbott Laboratories, Global Pharmaceutical Research and Development, Department R4CQ, AP52N, 200 Abbott Park Road, Abbott Park, IL 60064, USA. timothy.middleton@abbott.com
Hepatitis C virus (HCV) replicon-based shuttle vectors that permit phenotypes of NS5B polymerase genes from a large number of patient isolates to be rapidly assessed when transiently expressed in cultured cells were designed. When used to test responses to an inhibitor of HCV RNA-dependent RNA polymerase, IC(50) values for inhibition covered a several hundred-fold range among 47 patient samples tested. This observation highlights the variability that can be found by testing isolates derived from HCV-infected subjects. Partial suppression with a polymerase inhibitor of the most sensitive species permitted detection of minor quasispecies that were 7-200-fold more resistant than the bulk population in approximately half of the samples. Sequence analysis showed a wide range of amino acid changes not detected by conventional selection methods using laboratory-derived strains. This approach provides a means to assess variation in antiviral efficacy, and to predict possible responses in a clinical setting.
PMID: 17604129 [PubMed - indexed for MEDLINE]