Global Transcriptional Profiling Demonstrates the Combination of Type I and Type II Interferon Enhances Antiviral and Immune Responses at Clinically Relevant Doses

Abstract

A role for type II interferon (IFN-gamma) in resolving viral infection is suggested by the correlation of hepatitis C virus (HCV) clearance with enhancement of IFN-gamma-producing activated T cells in the resolution of acute HCV infection. Using vesicular stomatitis virus (VSV), a synergistic direct antiviral effect was documented using IFN-gamma1b and a potent, consensus type I IFN (IFN alfacon-1). Global expression profiling following EC50 exposure to IFN alfacon-1, IFN-gamma1b, or a cocktail of the two allowed the antiviral state to be correlated with induction of a subset of IFN-stimulated genes (ISGs). Genes identified through this analysis corresponded to classic antiviral components, ISGs more recently associated with direct antiviral functions, as well as expressed sequence tags (ESTs) and hypothetical proteins. The magnitude of these antiviral EC50-correlated expression events in human hepatoma (Huh7) cells exposed to clinically relevant doses of IFN alfacon-1, IFN-gamma1b, or a cocktail of the two was also probed because the standard of care for patients with chronic hepatitis C is type I IFN-containing regimens. Relative to type I IFNs used alone, the addition of type II IFN caused enhanced expression not only of many of the genes correlated with the direct antiviral state but also of genes involved in (1) antigen presentation to cytotoxic T lymphocytes (CTLs), (2) macrophage, natural killer (NK), and T helper 1 (Th1) cell recruitment and activation, (3) complement system function, (4) apoptosis, and (5) ISGs with unknown functions. As many of these processes are correlated clinically with resolution of chronic HCV infection, the combined use of these IFNs could display a beneficial effect on viral clearance in patients infected with HCV and other viruses through enhancement of one of these processes or of the direct antiviral state.

Changes in Gene Expression during Pegylated Interferon and Ribavirin Therapy of Chronic Hepatitis C Virus Distinguish Responders from Nonresponders to Antiviral Therapy

“…However, it is puzzling that AA had higher numbers of genes induced and slightly higher levels of gene expression at day 1 than others. Alpha interferon is known to act through induction of a large number of genes, the exact number and pattern of which have only been partially identified (33,34). In this study, 801 genes were found to be increased during peginterferon and ribavirin therapy; many, but not all, of these were known interferon-induced genes (see Tables S1 and S2 in the supplemental material).…”

Final results of a double-blind, placebo-controlled trial of the antifibrotic efficacy of interferon-γ1b in chronic hepatitis C patients with advanced fibrosis or cirrhosis

“…These results do not suggest there would be synergistic antiviral effects of IFN-␣ and IFN-␥1b; however, 3 publications suggest synergy exists in vitro. [22][23][24] Furthermore, other synergistic effects, both positive (antifibrotic) and nega- tive (hematological or systemic toxicities), could occur. A pilot dose-escalated, phase 2 trial evaluating the safety and tolerability of combination of IFN-␥1b and daily dosing of consensus IFN is currently in progress.…”

Preclinical Characteristics of the Hepatitis C Virus NS3/4A Protease Inhibitor ITMN-191 (R7227)

“…Huh7 cells harboring HCV replicon were grown under standard conditions (43). Serially diluted ITMN-191 was added to K2040 replicon cells 1 day after cell plating.…”

“…Huh7 cells harboring HCV replicon were grown under standard conditions (43), and HCV replicon levels were determined by quantification of a replicon-borne neomycin gene product (NPT II) using a commercially available enzyme-linked immunosorbent assay kit (Agdia, Elkhart,…”