title: Characterization of signaling pathways activated by the interleukin 1 (IL-1) receptor homologue T1/ST2. A role for Jun N-terminal kinase in IL-4 induction.
abstract: T1/ST2 is a member of the interleukin (IL)-1 receptor superfamily, possessing three immunoglobulin domains extracellularly and a Toll/IL1R (TIR) domain intracellularly. The ligand for T1/ST2 is not known. T1/ST2 is expressed on Type 2 T helper (Th2) cells, and its role appears to be in the regulation of Th2 cell function. Here, we have investigated T1/ST2 signal transduction, using either transient overexpression of T1/ST2 or a cross-linking monoclonal antibody to activate cells. We demonstrate that T1/ST2 does not activate the transcription factor NF-kappaB when overexpressed in murine thymoma EL4 cells, or in the mast cell line P815 treated with the anti-T1/ST2 antibody. However, a chimera comprising the extracellular domain of the type 1 IL-1 receptor and the intracellular domain of T1/ST2 activates NF-kappaB both by overexpression and in response to IL-1. This artificial activation requires the IL1RAcP recruited via the extracellular portion (IL1R1) of the chimera. T1/ST2 is, however, able to activate the transcription factor activator protein-1 (AP-1), increase phosphorylation of c-Jun, and activate the MAP kinases c-Jun N-terminal kinase (JNK), p42/p44 and p38. Anti-T1/ST2 also induces the selective expression of IL-4 but not IFN-gamma in naive T cells. Importantly, this effect is blocked by prior treatment with the JNK inhibitor SP600125 confirming that JNK as a key effector in T1/ST2 signaling. The lack of effect on NF-kappaB when T1/ST2 is homodimerized identifies T1/ST2 as the first member of the IL-1 receptor superfamily so far studied that is apparently unable to activate NF-kappaB, consistent with evidence indicating the lack of a role for NF-kappaB in Th2 cell function.
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D000943:Antigens, Differentiation / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D003432:Cross-Linking Reagents / Q000494:pharmacology; D016207:Cytokines / Q000378:metabolism; D019281:Dimerization; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D005260:Female; D005434:Flow Cytometry; D017930:Genes, Reporter; D005822:Genetic Vectors; D006801:Humans; D015151:Immunoblotting; D007371:Interferon-gamma / Q000378:metabolism; D000072179:Interleukin-1 Receptor-Like 1 Protein; D015847:Interleukin-4 / Q000378:metabolism*; D048031:JNK Mitogen-Activated Protein Kinases; D008024:Ligands; D008156:Luciferases / Q000378:metabolism; D048670:MAP Kinase Kinase 4; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D053594:Myeloid Differentiation Factor 88; D016328:NF-kappa B / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic / Q000378:metabolism; D018123:Receptors, Interleukin; D017472:Receptors, Interleukin-1 / Q000737:chemistry / Q000378:metabolism*; D015398:Signal Transduction; D018418:Th2 Cells / Q000378:metabolism; D014162:Transfection; D014407:Tumor Cells, Cultured; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D000943:Antigens, Differentiation; D003432:Cross-Linking Reagents; D016207:Cytokines; C079241:IL1RL1 protein, human; C486189:Il1rl1 protein, mouse; D000072179:Interleukin-1 Receptor-Like 1 Protein; D008024:Ligands; C507779:MYD88 protein, human; D008565:Membrane Proteins; C507780:Myd88 protein, mouse; D053594:Myeloid Differentiation Factor 88; D016328:NF-kappa B; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; D018123:Receptors, Interleukin; D017472:Receptors, Interleukin-1; D015847:Interleukin-4; D007371:Interferon-gamma; D008156:Luciferases; D048031:JNK Mitogen-Activated Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D020929:Mitogen-Activated Protein Kinase Kinases