AIM: To explore the properties of hypervariable region 1 (HVR1) in the envelope 2 gene of hepatitis C virus by analyzing the reactivity of HVR1 fusion proteins from different Chinese HCV strains with sera of patients with chronic hepatitis C and by comparing their reactivity between interferon therapy responders and non-responders. METHODS: Gene fragments of HVR1 of four HCV strains (three genotype 1b and one genotype 2a) were amplified from pGEMT-E2 plasmids and sub-cloned into pQE40 vectors respectively to construct recombinant expression plasmids which expressed HVR1 fused downstream to DHFR in Escherichia coli strain TG1. The purified DHFR- HVR1 proteins were then used to detect the anti-HVR1 antibodies in 70 serum samples of patients with chronic hepatitis C. RESULTS: Four DHFR- HVR1 fusion proteins were successfully expressed in E.coli (320-800 ug fusion proteins per 100 ml culture). Each fusion protein (SH1b, BJ1b, SD1b and SD2a) reacted with 72.8 % (51/70), 60 % (42/70), 48.6 % (34/70), and 58.6 % (41/30) of the anti-HCV positive patients' sera respectively by ELISA. 57 % (4/7) of non responders reacted with all four HVR1 fusion proteins, while only 15.3 % (2/13) of responders reacted with all of them. The O.D. values of sera from IFN therapy responders were significantly higher than those of non responders (P<0.05). CONCLUSION: The selected HVR1 fusion proteins expressed in E. coli can broadly react with HCV-infected patients' sera. The intensity and/or quality of the immune response against HCV may be a critical factor determining the response to interferon treatment. With the evolution of virus strains, anti-HVR1 antibodies can not neutralize all the quasispecies. A polyvalent and high immunogenic vaccine comprising a mixture of several HVR1 sequences that cover the reactivity of most HCV isolates may be useful.
AIM: To explore the properties of hypervariable region 1 (HVR1) in the envelope 2 gene of hepatitis C virus by analyzing the reactivity of HVR1 fusion proteins from different Chinese HCV strains with sera of patients with chronic hepatitis C and by comparing their reactivity between interferon therapy responders and non-responders. METHODS: Gene fragments of HVR1 of four HCV strains (three genotype 1b and one genotype 2a) were amplified from pGEMT-E2 plasmids and sub-cloned into pQE40 vectors respectively to construct recombinant expression plasmids which expressed HVR1 fused downstream to DHFR in Escherichia coli strain TG1. The purified DHFR- HVR1 proteins were then used to detect the anti-HVR1 antibodies in 70 serum samples of patients with chronic hepatitis C. RESULTS: Four DHFR- HVR1 fusion proteins were successfully expressed in E.coli (320-800 ug fusion proteins per 100 ml culture). Each fusion protein (SH1b, BJ1b, SD1b and SD2a) reacted with 72.8 % (51/70), 60 % (42/70), 48.6 % (34/70), and 58.6 % (41/30) of the anti-HCV positive patients' sera respectively by ELISA. 57 % (4/7) of non responders reacted with all four HVR1 fusion proteins, while only 15.3 % (2/13) of responders reacted with all of them. The O.D. values of sera from IFN therapy responders were significantly higher than those of non responders (P<0.05). CONCLUSION: The selected HVR1 fusion proteins expressed in E. coli can broadly react with HCV-infectedpatients' sera. The intensity and/or quality of the immune response against HCV may be a critical factor determining the response to interferon treatment. With the evolution of virus strains, anti-HVR1 antibodies can not neutralize all the quasispecies. A polyvalent and high immunogenic vaccine comprising a mixture of several HVR1 sequences that cover the reactivity of most HCV isolates may be useful.
Authors: M U Mondelli; A Cerino; A Lisa; S Brambilla; L Segagni; A Cividini; M Bissolati; G Missale; G Bellati; A Meola; B Bruniercole; A Nicosia; G Galfrè; E Silini Journal: Hepatology Date: 1999-08 Impact factor: 17.425
Authors: J Goto; S Nishimura; M Esumi; K Makizumi; T Rikihisa; T Nishihara; K Mizuno; Y -H. Zhou; T Shikata; S Fujiyama; K Tomita Journal: Hepatol Res Date: 2001-03-26 Impact factor: 4.288
Authors: T Poynard; P Marcellin; S S Lee; C Niederau; G S Minuk; G Ideo; V Bain; J Heathcote; S Zeuzem; C Trepo; J Albrecht Journal: Lancet Date: 1998-10-31 Impact factor: 79.321