title: The human IL-23 receptor rs11209026 A allele promotes the expression of a soluble IL-23R-encoding mRNA species.
abstract: The human IL23R gene single nucleotide polymorphism rs11209026 A allele confers protection against inflammatory diseases. However, although this difference has been associated with reductions in IL-23-induced IL-17A production and STAT3 phosphorylation, the molecular mechanism underlying these changes remains undefined. Th17 cell maturation depends on IL-23 signaling. Multiple splice forms of the human IL23R transcript exist, and one, Δ9, encodes a soluble form of the receptor. In this study, we asked whether this protective allele was associated with mRNA splicing. Using mini-gene constructs and competitive oligonucleotide binding, we showed that the A allele alters IL-23R α-chain mRNA splicing and favors exon 9 skipping by reducing the binding of the splicing enhancer SF2. This enhances expression of the Δ9 mRNA and consequently diminishes IL-23 signaling. Thus, the presence of the A allele increases expression of the soluble form of IL23R mRNA (which then functions as a decoy receptor) and lowers the ability to develop a Th17 phenotype upon IL-23 stimulation. We further showed that antisense oligonucleotides targeting the SF2 binding site could efficiently induce exon 9 skipping in the presence of the G allele, and thereby replicate the effect of the A allele. Antisense oligonucleotide treatment caused dose-responsive induction of the IL23RΔ9 mRNA and interfered with in vitro differentiation of human Th17 cells, reducing their expression of the signature Th17 cytokines IL-17A and IL-17F. This may represent a novel approach to therapy of Th17-mediated diseases by elevating soluble IL-23R while simultaneously reducing the remaining cell surface receptor density.
authors.affiliation: Genetic Immunology Laboratory, HUMIGEN, The Institute for Genetic Immunology, Genesis Biotechnology Group, Hamilton, NJ 08690.
authors.forename: Raymond Y
authors.initials: RY
authors.lastname: Yu
authors.affiliation: Genetic Immunology Laboratory, HUMIGEN, The Institute for Genetic Immunology, Genesis Biotechnology Group, Hamilton, NJ 08690.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Brazaitis
authors.affiliation: Genetic Immunology Laboratory, HUMIGEN, The Institute for Genetic Immunology, Genesis Biotechnology Group, Hamilton, NJ 08690 G.Gallagher@Humigen.org.
authors.forename: Grant
authors.initials: G
authors.lastname: Gallagher
mesh_terms: D000483:Alleles; D017398:Alternative Splicing; D001665:Binding Sites; D005786:Gene Expression Regulation; D006801:Humans; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D020320:Oligoribonucleotides, Antisense / Q000235:genetics / Q000378:metabolism; D020641:Polymorphism, Single Nucleotide; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D018123:Receptors, Interleukin / Q000235:genetics* / Q000378:metabolism; D000068103:Serine-Arginine Splicing Factors; D058504:Th17 Cells / Q000276:immunology / Q000378:metabolism
chemical_list: C515500:IL23R protein, human; D009687:Nuclear Proteins; D020320:Oligoribonucleotides, Antisense; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D018123:Receptors, Interleukin; D000068103:Serine-Arginine Splicing Factors