Ribavirin improves the IFN-? response of natural killer cells to IFN-based therapy of hepatitis C virus infection.

ABSTRACT: UNLABELLED:Ribavirin (RBV) is an important component of interferon (IFN)-based and direct antiviral treatment regimens for hepatitis C virus (HCV) infection. Immunomodulation, in particular improvement of the host IFN response, has been proposed as RBV's mechanism of action. Natural killer (NK) cells are sensitive biomarkers for IFN-?/? receptor signaling, as NK cell cytotoxicity and IFN-? production are regulated by signal transducer and activator of transcription (STAT)1- and STAT4-phosphorylation, respectively. Specifically, pSTAT1-dependent NK cell cytotoxicity increases and pSTAT4-dependent IFN-? production decreases in response to endogenous, virus-induced IFN-? and during IFN-?-based therapy. To assess whether RBV has a direct effect on NK cells and/or improves the IFN-? response of NK cells in the presence of IFN-?, we prospectively studied 22 HCV patients with and 32 patients without 4 weeks of RBV pretreatment, who all received subsequent pegylated (Peg)IFN/ribavirin combination therapy. During RBV pretreatment, both the frequency of CD56(dim) NK cells with cytotoxic effector functions and the frequency of CD56(bright) NK cells with the capacity to produce IFN-? decreased (P?=?0.049 and P?=?0.001, respectively). In vitro or in vivo exposure of NK cells to RBV improved the pSTAT4 (P?

SUBMITTER: Werner JM 

PROVIDER: S-EPMC4469648 | biostudies-literature | 2014 Oct

REPOSITORIES: biostudies-literature