title: Specific inhibition of interleukin-13 activity by a recombinant human single-chain immunoglobulin domain directed against the IL-13 receptor alpha1 chain.
abstract: Interleukin-13 (IL-13) is a T-cell-derived pleiotropic cytokine of particular medical importance because of its critical role in the development of allergic asthma. The effects of IL-13 on its target cells are mediated through a dimeric transmembrane receptor (IL-13R), which shares the IL-4Ralpha subunit with the IL-4R system, but contains as a specific component the IL-13Ralpha1 chain. We have generated a set of single-chain Fv fragments with specific binding capacity to the extracellular domain of the human IL-13Ralpha1 receptor. Bacteriophage clones displaying receptor-binding antibody domains were selected from both naive and synthetic libraries by repetitive panning on recombinant and cell surface-expressed recombinant IL-13Ralpha1. Their specific reactivity with native human IL-13Ralpha1 expressed on the surface of transfected cells was demonstrated by flow cytometry. One binder that specifically interfered with cell activation by IL-13 was extensively characterized. This scFv inhibited IL-13-driven gene transcription and cell proliferation in test cell lines, as well as IL-13-induced activation of primary human monocytes in a dose-dependent manner, with an IC(50) below 300 nM. This novel reagent thus constitutes a valuable tool for the further elucidation of IL-13 function in disease and offers potential therapeutic perspectives.
authors.affiliation: Affimed Therapeutics AG, Im Neuenheimer Feld 582, D-69120 Heidelberg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Knackmuss
authors.forename: Sebastian
authors.initials: S
authors.lastname: Krause
authors.forename: Kathrin
authors.initials: K
authors.lastname: Engel
authors.forename: Uwe
authors.initials: U
authors.lastname: Reusch
authors.forename: J Christian
authors.initials: JC
authors.lastname: Virchow
authors.forename: Thomas
authors.initials: T
authors.lastname: Mueller
authors.forename: Michael
authors.initials: M
authors.lastname: Kraich
authors.forename: Melvin
authors.initials: M
authors.lastname: Little
authors.forename: Werner
authors.initials: W
authors.lastname: Luttmann
authors.forename: Karlheinz
authors.initials: K
authors.lastname: Friedrich
mesh_terms: D002478:Cells, Cultured; D006801:Humans; D007136:Immunoglobulins / Q000276:immunology* / Q000494:pharmacology; D018793:Interleukin-13 / Q000037:antagonists & inhibitors*; D053661:Interleukin-13 Receptor alpha1 Subunit / Q000276:immunology*; D011485:Protein Binding; D011994:Recombinant Proteins / Q000276:immunology* / Q000494:pharmacology
chemical_list: D007136:Immunoglobulins; D018793:Interleukin-13; D053661:Interleukin-13 Receptor alpha1 Subunit; D011994:Recombinant Proteins