TY - JOUR
T1 - Ribavirin restores IFNα responsiveness in HCV-infected livers by epigenetic remodelling at interferon stimulated genes
AU - Testoni, Barbara
AU - Durantel, David
AU - Lebossé, Fanny
AU - Fresquet, Judith
AU - Helle, François
AU - Negro, Francesco
AU - Donato, Maria Francesca
AU - Levrero, Massimo
AU - Zoulim, Fabien
PY - 2016
Y1 - 2016
N2 - Objectives Caveats in the understanding of ribavirin (RBV) mechanisms of action has somehow prevented the development of better analogues able to further improve its therapeutic contribution in interferon (IFN)-based and direct antiviral agent-based regimens for chronic HCV or other indications. Here, we describe a new mechanism by which RBV modulates IFN-stimulated genes (ISGs) and contributes to restore hepatic immune responsiveness. Design RBV effect on ISG expression was monitored in vitro and in vivo, that is, in non-transformed hepatocytes and in the liver of RBV mono-treated patients, respectively. Modulation of histone modifications and recruitment of histone-modifying enzymes at target promoters was analysed by chromatin immunoprecipitation in RBV-treated primary human hepatocytes and in patients' liver biopsies. Results RBV decreases the mRNA levels of several abnormally preactivated ISGs in patients with HCV, who are non-responders to IFN therapy. RBV increases G9a histone methyltransferase recruitment and histone-H3 lysine-9 dimethylation/trimethylation at selected ISG promoters in vitro and in vivo. G9a pharmacological blockade abolishes RBV-induced ISG downregulation and severely impairs RBV ability to potentiate IFN antiviral action and induction of ISGs following HCV infection of primary human hepatocytes. Conclusions RBV-induced epigenetic changes, leading to decreased ISG expression, restore an IFN-responsive hepatic environment in patients with HCV, which may also prove useful in IFN-free regimens.
AB - Objectives Caveats in the understanding of ribavirin (RBV) mechanisms of action has somehow prevented the development of better analogues able to further improve its therapeutic contribution in interferon (IFN)-based and direct antiviral agent-based regimens for chronic HCV or other indications. Here, we describe a new mechanism by which RBV modulates IFN-stimulated genes (ISGs) and contributes to restore hepatic immune responsiveness. Design RBV effect on ISG expression was monitored in vitro and in vivo, that is, in non-transformed hepatocytes and in the liver of RBV mono-treated patients, respectively. Modulation of histone modifications and recruitment of histone-modifying enzymes at target promoters was analysed by chromatin immunoprecipitation in RBV-treated primary human hepatocytes and in patients' liver biopsies. Results RBV decreases the mRNA levels of several abnormally preactivated ISGs in patients with HCV, who are non-responders to IFN therapy. RBV increases G9a histone methyltransferase recruitment and histone-H3 lysine-9 dimethylation/trimethylation at selected ISG promoters in vitro and in vivo. G9a pharmacological blockade abolishes RBV-induced ISG downregulation and severely impairs RBV ability to potentiate IFN antiviral action and induction of ISGs following HCV infection of primary human hepatocytes. Conclusions RBV-induced epigenetic changes, leading to decreased ISG expression, restore an IFN-responsive hepatic environment in patients with HCV, which may also prove useful in IFN-free regimens.
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U2 - 10.1136/gutjnl-2014-309011
DO - 10.1136/gutjnl-2014-309011
M3 - Article
C2 - 26082258
AN - SCOPUS:84932625135
VL - 65
SP - 672
EP - 682
JO - Gut
JF - Gut
SN - 0017-5749
IS - 4
ER -