Interferon regulatory factor 5 gene variants and pharmacological and clinical outcome of Interferonβ therapy in multiple sclerosis.
ABSTRACT Interferon-β (IFNβ) therapy is effective in approximately half of the patients with relapsing-remitting multiple sclerosis (RRMS). Clinical non-responders were characterized by an increased expression of IFN response genes before the start of therapy, and a lack of a pharmacologically induced increase in IFN response gene activity. Because Interferon Regulatory Factor 5 (IRF5) is a master regulator of IFN-activity, we carried out a candidate gene study of IRF5 gene variants in relation to the pharmacological and clinical response upon IFNβ treatment. We found that patients with the IRF5 rs2004640-TT and rs47281420-AA genotype exerted a poor pharmacological response to IFNβ compared with patients carrying the respective G-alleles (P=0.0006 and P=0.0023, respectively). Moreover, patients with the rs2004640-TT genotype developed more magnetic resonance imaging (MRI)-based T2 lesions during IFNβ treatment (P=0.003). Accordingly, an association between MRI-based non-responder status and rs2004640-TT genotype was observed (P=0.010). For the rs4728142-AA genotype a trend of an association with more T2 lesions during IFNβ treatment and MRI-based non-responder status was observed (P=0.103 and P=0.154, respectively). The clinical relevance of the rs2004640-TT genotype was validated in an independent cohort wherein a shorter time to first relapse was found (P=0.037). These findings suggest a role for IRF5 gene variation in the pharmacological and clinical outcome of IFNβ therapy that might have relevance as biomarker to predict the response to IFNβ in multiple sclerosis.
- Annals of Neurology 04/1983; 13(3):227-31. · 11.19 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: The efficient and regulated response to cellular stress is coordinated by a genetic regulatory network in which a given transcription factor controls the expression of diverse target genes depending on the cell type and/or nature of the stimuli. The tumor suppressor p53 is thought to preferentially regulate the balance between cell survival and death. The interferon regulatory factor 5 (IRF-5), known to be involved in the innate immune response to pathogens, is also a critical regulator of DNA damage-induced apoptosis. Here, we provide direct evidence that IRF-5 promotes apoptosis upon signaling through tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) death receptors (DR). We report that IRF-5 sensitizes tumor cells to TRAIL-induced apoptosis and cell death that is further enhanced by type I interferons. Cells deficient of IRF-5 gave a significantly diminished response to these agents. IRF-5 is involved in DR signaling upstream of caspase 8, in part because of an IRF-5-dependent increase in caspase 8 activation. We provide evidence that TRAIL induces a signaling cascade that leads to the phosphorylation and nuclear localization of IRF-5, resulting in transactivation of key DR signaling components. The results presented here identify IRF-5 as a new mediator of DR signaling and provides molecular insight into the mechanism of TRAIL-induced IRF-5 signaling.Journal of Biological Chemistry 12/2008; 284(5):2767-77. · 4.65 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: In recent years, the study of systemic lupus erythematosus (SLE) patients has revealed a central role for type I interferon (IFN) in disease pathogenesis. IFN induces the unabated activation of peripheral dendritic cells, which select and activate autoreactive T cells rather than deleting them, thus failing to induce peripheral tolerance. IFN also directly affects T cells and B cells. Furthermore, immune complexes binding to FcgammaR and Toll-like receptors provide an amplification loop for IFN production and B-cell activation in SLE. Polymorphisms in genes that control IFN production or its downstream signaling pathway, such as IRF5, might be responsible for some of these alterations. This novel information is leading to the development of IFN antagonists as a potential therapeutic intervention in SLE, thus bringing hope to SLE patients.Current Opinion in Immunology 01/2007; 18(6):676-82. · 8.77 Impact Factor