TY - JOUR
T1 - DDX60L is an interferon-stimulated gene product restricting hepatitis C virus replication in cell culture
AU - Grunvogel, O
AU - Esser-Nobis, K
AU - Reustle, Anna
AU - Shult, P
AU - Muller, B
AU - Metz, Philippe
AU - Trippler, Martin
AU - Windisch, Marc
AU - FRESE, Michael
AU - Binder, Marco
AU - Fackler, Oliver
AU - Bartenschlager, Ralf
AU - Ruggieri, Alessia
AU - Lohmann, Volker
N1 - Copyright © 2015, American Society for Microbiology. All Rights Reserved.
PY - 2015/10
Y1 - 2015/10
N2 - All major types of interferon (IFN) efficiently inhibit hepatitis C virus (HCV) replication in vitro and in vivo. Remarkably, HCV replication is not sensitive to IFN-¿ in the hepatoma cell line Huh6, despite an intact signaling pathway. We performed transcriptome analyses between Huh6 and Huh-7 cells to identify effector genes of the IFN-¿ response and thereby identified the DExD/H box helicase DEAD box polypeptide 60-like (DDX60L) as a restriction factor of HCV replication. DDX60L and its homolog DEAD box polypeptide 60 (DDX60) were both induced upon viral infection and IFN treatment in primary human hepatocytes. However, exclusively DDX60L knockdown increased HCV replication in Huh-7 cells and rescued HCV replication from type II IFN as well as type I and III IFN treatment, suggesting that DDX60L is an important effector protein of the innate immune response against HCV. In contrast, we found no impact of DDX60L on replication of hepatitis A virus. DDX60L protein was detectable only upon strong ectopic overexpression, displayed a broad cytoplasmic distribution, but caused cytopathic effects under these conditions. DDX60L knockdown did not alter interferon-stimulated gene (ISG) induction after IFN treatment but inhibited HCV replication upon ectopic expression, suggesting that it is a direct effector of the innate immune response. It most likely inhibits viral RNA replication, since we found neither impact of DDX60L on translation or stability of HCV subgenomic replicons nor additional impact on assembly of infectious virus. Similar to DDX60, DDX60L had a moderate impact on RIG-I dependent activation of innate immunity, suggesting additional functions in the sensing of viral RNA.
AB - All major types of interferon (IFN) efficiently inhibit hepatitis C virus (HCV) replication in vitro and in vivo. Remarkably, HCV replication is not sensitive to IFN-¿ in the hepatoma cell line Huh6, despite an intact signaling pathway. We performed transcriptome analyses between Huh6 and Huh-7 cells to identify effector genes of the IFN-¿ response and thereby identified the DExD/H box helicase DEAD box polypeptide 60-like (DDX60L) as a restriction factor of HCV replication. DDX60L and its homolog DEAD box polypeptide 60 (DDX60) were both induced upon viral infection and IFN treatment in primary human hepatocytes. However, exclusively DDX60L knockdown increased HCV replication in Huh-7 cells and rescued HCV replication from type II IFN as well as type I and III IFN treatment, suggesting that DDX60L is an important effector protein of the innate immune response against HCV. In contrast, we found no impact of DDX60L on replication of hepatitis A virus. DDX60L protein was detectable only upon strong ectopic overexpression, displayed a broad cytoplasmic distribution, but caused cytopathic effects under these conditions. DDX60L knockdown did not alter interferon-stimulated gene (ISG) induction after IFN treatment but inhibited HCV replication upon ectopic expression, suggesting that it is a direct effector of the innate immune response. It most likely inhibits viral RNA replication, since we found neither impact of DDX60L on translation or stability of HCV subgenomic replicons nor additional impact on assembly of infectious virus. Similar to DDX60, DDX60L had a moderate impact on RIG-I dependent activation of innate immunity, suggesting additional functions in the sensing of viral RNA.
KW - Cell Line, Tumor
KW - Cell Survival
KW - DEAD Box Protein 58
KW - DEAD-box RNA Helicases/antagonists & inhibitors
KW - Gene Expression Regulation
KW - Genes, Reporter
KW - Genotype
KW - Hepacivirus/drug effects
KW - Hepatitis A virus/drug effects
KW - Hepatocytes/drug effects
KW - Host-Pathogen Interactions
KW - Humans
KW - Immunity, Innate
KW - Interferon-gamma/pharmacology
KW - Luciferases/genetics
KW - Primary Cell Culture
KW - Protein Isoforms/antagonists & inhibitors
KW - RNA, Small Interfering/genetics
KW - Replicon
KW - Signal Transduction
KW - Transcriptome
KW - Virus Replication/genetics
UR - http://www.scopus.com/inward/record.url?scp=84942155960&partnerID=8YFLogxK
U2 - 10.1128/JVI.01297-15
DO - 10.1128/JVI.01297-15
M3 - Article
C2 - 26269178
SN - 0022-538X
VL - 89
SP - 10548
EP - 10568
JO - Journal of Virology
JF - Journal of Virology
IS - 20
ER -