title: The impact of interleukin-6 promoter -597/-572/-174genotype on interleukin-6 production after lipopolysaccharide stimulation.
abstract: Interleukin (IL)-6 is a pleiotropic cytokine, produced by different cells. There is accumulating evidence that IL-6 promoter polymorphisms impact substantially on various diseases and we identified kidney transplant recipients carrying the IL-6 GGG/GGG (-597/-572/-174)genotype to have superior graft survival. To prove a functional impact on gene expression, we analysed systematically IL-6 production in healthy individuals with respect to the IL-6 (-597/-572/-174)genotype. IL-6 was determined in 100 healthy blood donors at protein and mRNA levels upon specific stimulation in monocytes and T lymphocytes under whole blood conditions. GGG/GGG individuals showed a lower IL-6 secretion upon lipopolysaccharide (LPS)-stimulation versus all others (P = 0.039). This link was even stronger when (-597) and (-174)GG genotypes were reanalysed separately (P = 0.008, P = 0.017). However, we found neither a difference at the mRNA level or percentage of CD14(+) cells nor after T cell stimulation. We found evidence for the IL-6 (-597/-572/-174)genotype to affect IL-6 synthesis, i.e. lower levels of IL-6 protein upon LPS-stimulation in GGG/GGG individuals. Further studies are needed in kidney transplant recipients to investigate the potential link between the GGG/GGG genotype and graft survival. In line with this, determination of the genetic risk profiles might be promising to improve the transplant outcome in the individual patient.
authors.affiliation: Institute of Transfusion Medicine and Immunology, Faculty of Medicine Mannheim, University of Heidelberg, Germany. m.mueller-steinhardt@blutspende.de
authors.forename: M
authors.initials: M
authors.lastname: Müller-Steinhardt
authors.forename: B
authors.initials: B
authors.lastname: Ebel
authors.forename: C
authors.initials: C
authors.lastname: Härtel
mesh_terms: D005434:Flow Cytometry / Q000379:methods; D015870:Gene Expression; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D015850:Interleukin-6 / Q000096:biosynthesis* / Q000235:genetics*; D016030:Kidney Transplantation / Q000276:immunology; D018950:Lipopolysaccharide Receptors / Q000032:analysis; D008070:Lipopolysaccharides / Q000096:biosynthesis*; D008213:Lymphocyte Activation / Q000276:immunology; D009000:Monocytes / Q000276:immunology; D016133:Polymerase Chain Reaction / Q000379:methods; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D015850:Interleukin-6; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D012333:RNA, Messenger