Transcripts from a Single Full-Length cDNA Clone of Hepatitis C Virus are Infectious When Directly Transfected into the Liver of a Chimpanzee

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 94; no. 16; pp. 8738 - 8743
• Main Authors: Yanagi, Masayuki, Purcell, Robert H., Emerson, Suzanne U., Bukh, Jens
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 05.08.1997; National Acad Sciences; National Academy of Sciences; The National Academy of Sciences of the USA
• Subjects: Animals; Base Sequence; Biological Sciences; Cloning; Complementary DNA; Consensus sequence; DNA, Complementary - genetics; Five prime untranslated regions; Genetic Vectors; Genomes; Hepacivirus - genetics; Hepatitis; Hepatitis C; Hepatitis C - genetics; Hepatitis C - virology; Liver - virology; Medical research; Molecular Sequence Data; Monkeys & apes; Open reading frames; Pan troglodytes; Polymerase chain reaction; Reverse transcriptase polymerase chain reaction; RNA; RNA, Viral - genetics; Three prime untranslated regions; Transcription, Genetic; Transfection; Untranslated regions
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.94.16.8738

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.