Genetic variants and disease-associated factors contribute to enhanced interferon regulatory factor 5 expression in blood cells of patients with systemic lupus erythematosus
2010 (English)In: Arthritis and Rheumatism, ISSN 0004-3591, E-ISSN 1529-0131, Vol. 62, no 2, 562-573 p.Article in journal (Refereed) Published
OBJECTIVE: Genetic variants of the interferon (IFN) regulatory factor 5 gene (IRF5) are associated with susceptibility to systemic lupus erythematosus (SLE). The contribution of these variants to IRF-5 expression in primary blood cells of SLE patients has not been addressed, nor has the role of type I IFNs. The aim of this study was to determine the association between increased IRF-5 expression and the IRF5 risk haplotype in SLE patients. METHODS: IRF-5 transcript and protein levels in 44 Swedish patients with SLE and 16 healthy controls were measured by quantitative real-time polymerase chain reaction, minigene assay, and flow cytometry. Single-nucleotide polymorphisms rs2004640, rs10954213, and rs10488631 and the CGGGG insertion/deletion were genotyped in these patients. Genotypes of these polymorphisms defined both a common risk haplotype and a common protective haplotype. RESULTS: IRF-5 expression and alternative splicing were significantly up-regulated in SLE patients compared with healthy donors. Enhanced transcript and protein levels were associated with the risk haplotype of IRF5; rs10488631 displayed the only significant independent association that correlated with increased transcription from the noncoding first exon 1C. Minigene experiments demonstrated an important role for rs2004640 and the CGGGG insertion/deletion, along with type I IFNs, in regulating IRF5 expression. CONCLUSION: This study provides the first formal proof that IRF-5 expression and alternative splicing are significantly up-regulated in primary blood cells of patients with SLE. Furthermore, the risk haplotype is associated with enhanced IRF-5 transcript and protein expression in patients with SLE.
Place, publisher, year, edition, pages
2010. Vol. 62, no 2, 562-573 p.
IRF5, type I IFN, interferon, lupus, SLE
Medical and Health Sciences
Research subject Medicine
IdentifiersURN: urn:nbn:se:uu:diva-121253DOI: 10.1002/art.27223ISI: 000279432100035PubMedID: 20112383OAI: oai:DiVA.org:uu-121253DiVA: diva2:304799