抄録
We isolated cDNA of the whole genome of hepatitis C virus (HCV) from a single Japanese patient. HCV genome was about 9.4 kb in length, and encoded a single polyprotein consisting of 3010 to 3014 aa. The hydropathic profile of HCV polyprotein was similar to those of flaviviruses and pestiviruses, and the ccnsensus sequences of serine protease, helicase and RNA-dependent RNA polymerase of these viruses were also found in HCV polyprotein. Thus HCV is a member of new virus family related to flaviviruses and pestiviruses.
Our isolated cDNA clone, HCV-N, had 78% of nucleotide sequence homology and 84% of amino acid sequence homology with an American isolate, HCV-1, but 91-92% and 93-94% with other Japanese isolates, respectively. Thus Japanese isolates belong to a different type of HCV from an American isolate. However, the nucleotide sequence of 5'-non-coding region was so conserved among these isolates by 99-100% of homology that this region was useful to detect HCV RNA sequence beyond viral heterogeneity.
Using our isolated cDNA clones of HCV, we expressed several viral peptides in Escherichia coli and used to detect anti-HCV antibodies in patients' sera. Anticore peptide antibody was the most efficiently detected in hepatitis C patients. The combined use of anti-core and anti-NS 3/NS 4/NS 5 antibody assays was more efficient for the diagnosis of hepatitis C and the screening of blood donors.
