title: Soluble IL-1 receptor type I binds to human dermal fibroblasts and induces calcium flux.
abstract: Soluble cytokine receptors appear to modify ligand concentrations by stabilizing ligands or by specifically inhibiting interactions of ligands with their membrane-bound receptors. Here we describe a new function of the soluble interleukin-1 receptor type I (IL-1sR I). This receptor induced a transient rise of intracellular free calcium concentration in human dermal fibroblasts in a dose-dependent fashion. Mobilization of calcium by IL-1sR I was abolished in the presence of an equimolar concentration of IL-1 receptor antagonist (IL-1ra). Neutralizing antibodies against IL-1beta also abolished calcium mobilization stimulated with IL-1sR I indicating that IL-1beta is involved. IL-1sR I bound with high affinity (Kd 1-2 nM) to the fibroblasts. In addition, IL-1sR I enhanced expression of IL-6 and IL-8 mRNA. The observation that IL-1sR I can act as a ligand and agonist for membrane IL-1 extends the concept of the ligand-receptor functions of both IL-1 and IL-1sR I and adds a new dimension to the cytokine network.
authors.affiliation: Laboratory of Oral Cell Biology, Bern, Switzerland.
authors.forename: B
authors.initials: B
authors.lastname: Spörri
authors.forename: U N
authors.initials: UN
authors.lastname: Wiesmann
authors.forename: R M
authors.initials: RM
authors.lastname: Ochsenbein
authors.forename: M
authors.initials: M
authors.lastname: Loetscher
authors.forename: E R
authors.initials: ER
authors.lastname: Waelti
authors.forename: D
authors.initials: D
authors.lastname: Lottaz
authors.forename: M
authors.initials: M
authors.lastname: Bickel
mesh_terms: D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D007375:Interleukin-1 / Q000378:metabolism; D015850:Interleukin-6 / Q000235:genetics; D016209:Interleukin-8 / Q000235:genetics; D017136:Ion Transport; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics; D017472:Receptors, Interleukin-1 / Q000378:metabolism*; D012867:Skin / Q000166:cytology / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D007375:Interleukin-1; D015850:Interleukin-6; D016209:Interleukin-8; D012333:RNA, Messenger; D017472:Receptors, Interleukin-1; D002118:Calcium