TRANSCRIPTS OF A CHIMERIC CDNA CLONE OF HEPATITIS-C VIRUS GENOTYPE 1BARE INFECTIOUS IN-VIVO

We constructed a chimeric cDNA clone of hepatitis C virus (HCV) that i s infectious. The chimeric genome encodes the polyprotein of a genotyp e Ib strain (HC-J4) of HCV and replicates via 5' and 3' untranslated r egions of a genotype la strain. The infectivity of three full-length c DNA clones was tested by direct injection of RNA transcripts into the liver of a chimpanzee. The chimpanzee became infected with HCV and the viral titer increased over time from 10(2) genome equivalents (GE)/ml at week 1 postinoculation (p.i.) to 10(4)-10(5) GE/ml during weeks 3- 11 p.i. Antibodies to HCV were detected from week 18 p.i. However, the chimpanzee did not develop hepatitis. Sequence analysis of PCR produc ts amplified from the serum of the chimpanzee demonstrated that only o ne of the three clones was infectious. Sequence comparisons with the c loning source, an acute-phase infectious plasma pool derived from an e xperimentally infected chimpanzee, showed that this infectious clone h ad three amino acids that differed from the consensus sequence of HC-J 4, whereas the two noninfectious clones had seven and nine amino acid differences, respectively. Together, genotype Ib, represented by the i nfectious molecular clone described herein, and genotype la, represent ed by the two cDNA clones previously shown to be infectious for chimpa nzees, account for the majority of HCV infections in the United States , Europe, and Japan. (C) 1998 Academic Press.