Transcripts from a single full-length cDNA clone of hepatitis C virus are infectious when directly transfected into the liver of a chimpanzee

Transcripts from a single full-length cDNA clone of hepatitis C virus are infectious when directly transfected into the liver of a chimpanzee

Hepatitis Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892

Abstract

We have succeeded in constructing a stable full-length cDNA clone of strain H77 (genotype 1a) of hepatitis C virus (HCV). We devised a cassette vector with fixed 5′ and 3′ termini and constructed multiple full-length cDNA clones of H77 in a single step by cloning of the entire ORF, which was amplified by long reverse transcriptase–PCR, directly into this vector. The infectivity of two complete full-length cDNA clones was tested by the direct intrahepatic injection of a chimpanzee with RNA transcripts. However, we found no evidence for HCV replication. Sequence analysis of these and 16 additional full-length clones revealed that seven clones were defective for polyprotein synthesis, and the remaining nine clones had 6–28 amino acid mutations in the predicted polyprotein compared with the consensus sequence of H77. Next, we constructed a consensus chimera from four of the full-length cDNA clones with just two ligation steps. Injection of RNA transcripts from this consensus clone into the liver of a chimpanzee resulted in viral replication. The sequence of the virus recovered from the chimpanzee was identical to that of the injected RNA transcripts. This stable infectious molecular clone should be an important tool for developing a better understanding of the molecular biology and pathogenesis of HCV.

Footnotes

↵ * To whom reprint requests should be addressed at: National Institutes of Health, National Institute of Allergy and Infectious Diseases, Laboratory of Infectious Diseases, Hepatitis Viruses Section, Building 7, Room 201, 7 Center Drive, MSC 0740, Bethesda, MD 20892-0740.
Robert H. Purcell
Data deposition: The sequences reported in this paper have been deposited in the GenBank database (accession nos. AF011751–AF011753).
↵ † Fourth International Meeting on Hepatitis C Virus and Related Viruses, March 6–10, 1997, Kyoto, Japan.
ABBREVIATIONS:

HCV,

hepatitis C virus;

UTR,

untranslated region;

RT-PCR,

reverse transcriptase–PCR;

GE,

genome equivalents;

p.i.,

postinoculation