101. Ribavirin improves the IFN-γ response of natural killer cells to IFN-based therapy of hepatitis C virus infection.
- Author
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Werner JM, Serti E, Chepa-Lotrea X, Stoltzfus J, Ahlenstiel G, Noureddin M, Feld JJ, Liang TJ, Rotman Y, and Rehermann B
- Subjects
- Adult, Antiviral Agents pharmacology, Drug Therapy, Combination, Female, Hepatitis C metabolism, Hepatitis C pathology, Humans, In Vitro Techniques, Interferon-alpha metabolism, Interferon-alpha pharmacology, Killer Cells, Natural drug effects, Killer Cells, Natural pathology, Male, Middle Aged, Polyethylene Glycols pharmacology, Prospective Studies, Recombinant Proteins pharmacology, Recombinant Proteins therapeutic use, Ribavirin pharmacology, STAT1 Transcription Factor metabolism, STAT4 Transcription Factor metabolism, Signal Transduction drug effects, Treatment Outcome, Antiviral Agents therapeutic use, Hepacivirus, Hepatitis C drug therapy, Interferon-alpha therapeutic use, Interferon-gamma metabolism, Killer Cells, Natural metabolism, Polyethylene Glycols therapeutic use, Ribavirin therapeutic use
- 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-α/β receptor signaling, as NK cell cytotoxicity and IFN-γ 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-γ production decreases in response to endogenous, virus-induced IFN-α and during IFN-α-based therapy. To assess whether RBV has a direct effect on NK cells and/or improves the IFN-γ response of NK cells in the presence of IFN-α, 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-γ decreased (P = 0.049 and P = 0.001, respectively). In vitro or in vivo exposure of NK cells to RBV improved the pSTAT4 (P < 0.01) but not pSTAT1 response of NK cells to subsequent stimulation with IFN-α. This was associated with an increase in IFN-γ production but not cytotoxicity of NK cells during subsequent IFN-α-based therapy. The frequency of IFN-γ-producing NK cells was greater in fast second-phase virological responders than in slow responders., Conclusion: RBV enhances the pSTAT4 and IFN-γ response of NK cells to IFN-α-stimulation., (Published 2014. This article is a U.S. Government work and is in the public domain in the USA.)
- Published
- 2014
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