TY - JOUR

T1 - Hypervariable region 1 differentially impacts viability of hepatitis C virus strains of genotypes 1 to 6 and impairs virus neutralization

AU - Prentø, Jannick Cornelius

AU - Jensen, Tanja Bertelsen

AU - Meuleman, Philip

AU - Serre, Stephanie

AU - Scheel, Troels Kasper Høyer

AU - Leroux-Roels, Geert

AU - Gottwein, Judith

AU - Bukh, Jens

PY - 2011

Y1 - 2011

N2 - Hypervariable region 1 (HVR1) of hepatitis C virus (HCV) E2 envelope glycoprotein has been implicated in virus neutralization and persistence. We deleted HVR1 from JFH1-based HCV recombinants expressing Core/E1/E2/p7/NS2 of genotypes 1 to 6, previously found to grow efficiently in human hepatoma Huh7.5 cells. The 2a(¿HVR1), 5a(¿HVR1), and 6a(¿HVR1) Core-NS2 recombinants retained viability in Huh7.5 cells, whereas 1a(¿HVR1), 1b(¿HVR1), 2b(¿HVR1), 3a(¿HVR1), and 4a(¿HVR1) recombinants were severely attenuated. However, except for recombinant 4a(¿HVR1), viruses eventually spread, and reverse genetics studies revealed adaptive envelope mutations that rescued the infectivity of 1a(¿HVR1), 1b(¿HVR1), 2b(¿HVR1), and 3a(¿HVR1) recombinants. Thus, HVR1 might have distinct functional roles for different HCV isolates. Ultracentrifugation studies showed that deletion of HVR1 did not alter HCV RNA density distribution, whereas infectious particle density changed from a range of 1.0 to 1.1 g/ml to a single peak at ~1.1 g/ml, suggesting that HVR1 was critical for low-density HCV particle infectivity. Using chronic-phase HCV patient sera, we found three distinct neutralization profiles for the original viruses with these genotypes. In contrast, all HVR1-deleted viruses were highly sensitive with similar neutralization profiles. In vivo relevance for the role of HVR1 in protecting HCV from neutralization was demonstrated by ex vivo neutralization of 2a and 2a(¿HVR1) produced in human liver chimeric mice. Due to the high density and neutralization susceptibility of HVR1-deleted viruses, we investigated whether a correlation existed between density and neutralization susceptibility for the original viruses with genotypes 1 to 6. Only the 2a virus displayed such a correlation. Our findings indicate that HVR1 of HCV shields important conserved neutralization epitopes with implications for viral persistence, immunotherapy, and vaccine development.

AB - Hypervariable region 1 (HVR1) of hepatitis C virus (HCV) E2 envelope glycoprotein has been implicated in virus neutralization and persistence. We deleted HVR1 from JFH1-based HCV recombinants expressing Core/E1/E2/p7/NS2 of genotypes 1 to 6, previously found to grow efficiently in human hepatoma Huh7.5 cells. The 2a(¿HVR1), 5a(¿HVR1), and 6a(¿HVR1) Core-NS2 recombinants retained viability in Huh7.5 cells, whereas 1a(¿HVR1), 1b(¿HVR1), 2b(¿HVR1), 3a(¿HVR1), and 4a(¿HVR1) recombinants were severely attenuated. However, except for recombinant 4a(¿HVR1), viruses eventually spread, and reverse genetics studies revealed adaptive envelope mutations that rescued the infectivity of 1a(¿HVR1), 1b(¿HVR1), 2b(¿HVR1), and 3a(¿HVR1) recombinants. Thus, HVR1 might have distinct functional roles for different HCV isolates. Ultracentrifugation studies showed that deletion of HVR1 did not alter HCV RNA density distribution, whereas infectious particle density changed from a range of 1.0 to 1.1 g/ml to a single peak at ~1.1 g/ml, suggesting that HVR1 was critical for low-density HCV particle infectivity. Using chronic-phase HCV patient sera, we found three distinct neutralization profiles for the original viruses with these genotypes. In contrast, all HVR1-deleted viruses were highly sensitive with similar neutralization profiles. In vivo relevance for the role of HVR1 in protecting HCV from neutralization was demonstrated by ex vivo neutralization of 2a and 2a(¿HVR1) produced in human liver chimeric mice. Due to the high density and neutralization susceptibility of HVR1-deleted viruses, we investigated whether a correlation existed between density and neutralization susceptibility for the original viruses with genotypes 1 to 6. Only the 2a virus displayed such a correlation. Our findings indicate that HVR1 of HCV shields important conserved neutralization epitopes with implications for viral persistence, immunotherapy, and vaccine development.

U2 - http://dx.doi.org/10.1128/JVI.01594-10

DO - http://dx.doi.org/10.1128/JVI.01594-10

M3 - Journal article

VL - 85

SP - 2224

EP - 2234

JO - Journal of Virology

JF - Journal of Virology

SN - 0022-538X

IS - 5

ER -