Anti-IFI27 (full length) polyclonal antibody

The cytokine, Interferon (IFN)-alpha, induces a wide spectrum of anti-viral mediators, via the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway. STAT1 and STAT2 are well characterised to upregulate IFN-stimulated gene (ISG) expression; but even though STAT3 is also activated by IFN-alpha, its role in anti-viral ISG induction is unclear. Several viruses, including Hepatitis C and Mumps, reduce cellular STAT3 protein levels, via the promotion of ubiquitin-mediated proteasomal degradation. This viral immune evasion mechanism suggests an undiscovered anti-viral role for STAT3 in IFN-alpha signalling. To investigate STAT3's functional involvement in this Type I IFN pathway, we first analysed its effect upon the replication of two viruses, Influenza and Vaccinia. Viral plaque assays, using Wild Type (WT) and STAT3-/- Murine Embryonic Fibroblasts (MEFs), revealed that STAT3 is required for the inhibition of Influenza and Vaccinia replication. Furthermore, STAT3 shRNA knockdown also enhanced Influenza replication and hindered induction of several, well characterised, anti-viral ISGs: PKR, OAS2, MxB and ISG15; while STAT3 expression had no effect upon induction of a separate ISG group: Viperin, IFI27, CXCL10 and CCL5. These discoveries reveal, for the first time, an anti-viral role for STAT3 in the IFN-alpha pathway and characterise a requirement for STAT3 in the expression of specific ISGs. These findings also identify STAT3 as a therapeutic target against viral infection and highlight it as an essential pathway component for endogenous and therapeutic IFN-alpha responsiveness.

The aim of our study was to evaluate the significance of IL-28B single-nucleotide polymorphism and hepatic expression of IFI27, SOCS3 and miR-122 in order to predict early virological response (EVR) in patients infected with HCV genotype 1 or 4. The study group consisted of 65 patients: 46 with HCV mono- and 19 with HIV/HCV co-infection. Analyses of IL-28B single-nucleotide polymorphism C/T (rs12979860) in the blood and expression of SOCS3, IFI27 and miR-122 in liver biopsy samples obtained before PegIFN and ribavirin treatment were performed by the RT-PCR method. EVR was defined as a > 2log decline in HCV viremia at week 12. EVR was associated with a lower expression of IFI27 and a more frequent presence of the IL28BCC genotype. IFI27 expression was lower in patients with the CC genotype, irrespective of EVR. In multivariate logistic regression, only IL28B CC genotype and age above 40 years influenced EVR (OR =5.09 and 0.29 respectively). In contrast to IFI27, expression of miR-122 and SOCS3 in patients with different IL28B genotypes was not statistically significantly different. A correlation between miR-122 and SOCS3 was found (Rho =0.495094 p < 0.0001). Analysis of IFI27, SOCS3 and miR-122 hepatic expression does not provide substantial benefits for the prognosis of EVR. The only independent prognostic factors for EVR are age and IL28B genotype. The prognostic significance of IFI27 expression for EVR is dependent on the genetic polymorphism of IL28B.