Specific inhibition of interleukin-13 activity by a recombinant human single-chain immunoglobulin domain directed against the IL-13 receptor alpha1 chain.
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.
Knackmuss
Stefan
S
Affimed Therapeutics AG, Im Neuenheimer Feld 582, D-69120 Heidelberg, Germany.
Krause
Sebastian
S
Engel
Kathrin
K
Reusch
Uwe
U
Virchow
J Christian
JC
Mueller
Thomas
T
Kraich
Michael
M
Little
Melvin
M
Luttmann
Werner
W
Friedrich
Karlheinz
K
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
D007136:Immunoglobulins; D018793:Interleukin-13; D053661:Interleukin-13 Receptor alpha1 Subunit; D011994:Recombinant Proteins