Immune Reactivity of Synthetic Peptides Originated from Hypervariable Region 1 of Hepatitis C Synthetic Consensuses with Egyptian Sera Infected with Hepatitis C Virus Type 4.

We have studied the immune reactivity of hypervariable region 1 (HVR1) of hepatitis C virus (HCV) against HCV immune positive and negative sera. Two published HVR1 consensus nucleotide sequences (Italian and Chinese) were synthesized, and with both of them, a splicing by overlap extension polymerase chain reaction, cloning and sequencing were performed. From the corresponding amino acid sequences, 3 Italian and 1 Chinese HVR1 peptides were selected for synthesis. The 4 peptides (MB1-MB4; GenBank No.: HQ846888-HQ846891) were used to screen 47 and 31 HCV (type 4) immune positive and negative sera, respectively, by enzyme-linked immunosorbent assay (ELISA). The 3 Italian HVR1 peptides (MB1, MB2, MB3) showed reactivities of 83, 68 and 76.6%, respectively, while the Chinese HVR1 peptide (MB4) showed a reactivity of 80.8%. Our results supported that the HVR1 is an attractive target for a peptide-based vaccine as it contains neutralizing epitopes, and all of the HCV patients' sera used in this study have anti-HVR1 antibodies. Interestingly, the amino acid sequence of peptide MB1 has a close sequence similarity with the published mimotope R9, and it shows a high ELISA reactivity. So, MB1 could be tested in combination with other HCV-related peptides as a supplemental assay for HCV diagnosis.