Abstract:
The cytotoxic T cell response to the protein encoded by the NS5 region of hepatitis C virus was determined using 28 peptides from NS5 which were selected by an amphipathicity algorithm as candidates for T cell epitopes. In BALB/c mice, a single relatively conserved epitope represented by a 16-residue synthetic peptide was presented by D. sup. d class I major histocompatibility complex (MHC) molecules to conventional CD4. sup. - CD8. sup. + CTL. An exemplary peptide, which represents amino acid residues 2422-2437 of the polyprotein of the Chiron HCV1 isolate, had the amino acid sequence MSYSWTGALVTPCAAE [SEQ ID NO: 1]. A CTL line specific for this peptide recognized the two known natural variants of this NS5 sequence, each with conservative substitutions. Thus, CTL can recognize the product of the HCV NS5 gene, the probable RNA polymerase, in association with class I MHC molecules on model target cells and may recognize the same epitope on hepatocytes or any other cells infected with the virus.