title: Technical advance: soluble OX40 molecule mimics regulatory T cell modulatory activity on FcεRI-dependent mast cell degranulation.
abstract: Tregs play a central role in modulating FcεRI-dependent MC effector functions in the course of the allergic response. Cellular interaction depends on the constitutive expression of OX40 on Tregs and the OX40L counterpart on MCs. Study of OX40L signaling on MCs is hampered by the need of a highly purified molecule, which triggers OX40L specifically. We now report that sOX40 mimics the physiological activity of Treg interaction by binding to activated MCs. When treated with sOX40, activated MCs showed decreased degranulation and Ca(++) influx, whereas PLC-γ2 phosphorylation remained unaffected. Once injected into experimental animals, sOX40 not only located within the endothelium but also in parenchyma, where it could be found in close proximity and apparently bound to MCs. This soluble molecule triggers MC-OX40L without the requirement of Tregs, thus allowing study of OX40L signaling pathways in MCs and in other OX40L-expressing cell populations. Importantly, as sOX40 inhibits MC degranulation, it may provide an in vivo therapeutic tool in allergic disease.
authors.affiliation: Department of Biomedical Science and Technology, University of Udine, Udine, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Sibilano
authors.forename: Giorgia
authors.initials: G
authors.lastname: Gri
authors.forename: Barbara
authors.initials: B
authors.lastname: Frossi
authors.forename: Claudio
authors.initials: C
authors.lastname: Tripodo
authors.forename: Ryo
authors.initials: R
authors.lastname: Suzuki
authors.forename: Juan
authors.initials: J
authors.lastname: Rivera
authors.forename: Andrew S
authors.initials: AS
authors.lastname: MacDonald
authors.forename: Carlo E
authors.initials: CE
authors.lastname: Pucillo
mesh_terms: D000818:Animals; D015550:Cell Degranulation / Q000187:drug effects* / Q000235:genetics / Q000276:immunology; D006967:Hypersensitivity / Q000188:drug therapy / Q000276:immunology / Q000378:metabolism; D008407:Mast Cells / Q000276:immunology / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000819:agonists* / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D053278:OX40 Ligand; D051966:Phospholipase C gamma / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects / Q000235:genetics / Q000276:immunology; D017455:Receptors, IgE / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D053262:Receptors, OX40 / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology*; D012995:Solubility; D050378:T-Lymphocytes, Regulatory / Q000276:immunology / Q000378:metabolism; D048069:Tumor Necrosis Factors / Q000819:agonists* / Q000235:genetics / Q000276:immunology / Q000378:metabolism
chemical_list: D008562:Membrane Glycoproteins; D053278:OX40 Ligand; D017455:Receptors, IgE; D053262:Receptors, OX40; C505717:Tnfrsf4 protein, mouse; C504586:Tnfsf4 protein, mouse; D048069:Tumor Necrosis Factors; D051966:Phospholipase C gamma