Characterization of nonprimate hepacivirus and construction of a functional molecular clone

TY - JOUR

T1 - Characterization of nonprimate hepacivirus and construction of a functional molecular clone

AU - Scheel, Troels K H

AU - Kapoor, Amit

AU - Nishiuchi, Eiko

AU - Brock, Kenny V

AU - Yu, Yingpu

AU - Andrus, Linda

AU - Gu, Meigang

AU - Renshaw, Randall W

AU - Dubovi, Edward J

AU - McDonough, Sean P

AU - Van de Walle, Gerlinde R

AU - Lipkin, W Ian

AU - Divers, Thomas J

AU - Tennant, Bud C

AU - Rice, Charles M

PY - 2015/2/17

Y1 - 2015/2/17

N2 - Nonprimate hepacivirus (NPHV) is the closest known relative of hepatitis C virus (HCV) and its study could enrich our understanding of HCV evolution, immunity, and pathogenesis. High seropositivity is found in horses worldwide with ∼ 3% viremic. NPHV natural history and molecular virology remain largely unexplored, however. Here, we show that NPHV, like HCV, can cause persistent infection for over a decade, with high titers and negative strand RNA in the liver. NPHV is a near-universal contaminant of commercial horse sera for cell culture. The complete NPHV 3'-UTR was determined and consists of interspersed homopolymer tracts and an HCV-like 3'-terminal poly(U)-X-tail. NPHV translation is stimulated by miR-122 and the 3'-UTR and, similar to HCV, the NPHV NS3-4A protease can cleave mitochondrial antiviral-signaling protein to inactivate the retinoic acid-inducible gene I pathway. Using an NPHV consensus cDNA clone, replication was not observed in primary equine fetal liver cultures or after electroporation of selectable replicons. However, intrahepatic RNA inoculation of a horse initiated infection, yielding high RNA titers in the serum and liver. Delayed seroconversion, slightly elevated circulating liver enzymes and mild hepatitis was observed, followed by viral clearance. This establishes the molecular components of a functional NPHV genome. Thus, NPHV appears to resemble HCV not only in genome structure but also in its ability to establish chronic infection with delayed seroconversion and hepatitis. This NPHV infectious clone and resulting acute phase sera will facilitate more detailed studies on the natural history, pathogenesis, and immunity of this novel hepacivirus in its natural host.

AB - Nonprimate hepacivirus (NPHV) is the closest known relative of hepatitis C virus (HCV) and its study could enrich our understanding of HCV evolution, immunity, and pathogenesis. High seropositivity is found in horses worldwide with ∼ 3% viremic. NPHV natural history and molecular virology remain largely unexplored, however. Here, we show that NPHV, like HCV, can cause persistent infection for over a decade, with high titers and negative strand RNA in the liver. NPHV is a near-universal contaminant of commercial horse sera for cell culture. The complete NPHV 3'-UTR was determined and consists of interspersed homopolymer tracts and an HCV-like 3'-terminal poly(U)-X-tail. NPHV translation is stimulated by miR-122 and the 3'-UTR and, similar to HCV, the NPHV NS3-4A protease can cleave mitochondrial antiviral-signaling protein to inactivate the retinoic acid-inducible gene I pathway. Using an NPHV consensus cDNA clone, replication was not observed in primary equine fetal liver cultures or after electroporation of selectable replicons. However, intrahepatic RNA inoculation of a horse initiated infection, yielding high RNA titers in the serum and liver. Delayed seroconversion, slightly elevated circulating liver enzymes and mild hepatitis was observed, followed by viral clearance. This establishes the molecular components of a functional NPHV genome. Thus, NPHV appears to resemble HCV not only in genome structure but also in its ability to establish chronic infection with delayed seroconversion and hepatitis. This NPHV infectious clone and resulting acute phase sera will facilitate more detailed studies on the natural history, pathogenesis, and immunity of this novel hepacivirus in its natural host.

KW - 3' Untranslated Regions

KW - Cloning, Molecular

KW - DNA, Complementary

KW - Hepacivirus

KW - Molecular Sequence Data

KW - Protein Biosynthesis

KW - Viral Load

KW - Virus Replication

U2 - 10.1073/pnas.1500265112

DO - 10.1073/pnas.1500265112

M3 - Journal article

C2 - 25646476

SN - 0027-8424

VL - 112

SP - 2192

EP - 2197

JO - Proceedings of the National Academy of Sciences of the United States of America

JF - Proceedings of the National Academy of Sciences of the United States of America

IS - 7

ER -