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Interleukin‐1 receptor accessory protein interacts with the type II interleukin‐1 receptor
Author(s) -
Malinowsky David,
Lundkvist Johan,
Layé Sophie,
Bartfai Tamas
Publication year - 1998
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(98)00467-0
Subject(s) - interleukin 1 receptor , transfection , receptor , microbiology and biotechnology , complementary dna , chemistry , extracellular , hek 293 cells , biology , gene , interleukin , cytokine , biochemistry , immunology
Stably transfected HEK‐293 cells express on their surface the murine type II IL‐1 receptor (mIL‐1RII) as demonstrated by FACS analysis using the mAb 4E2, however binding of [ 125 I]‐hrIL‐1β to these cells is nearly absent. Saturable high affinity binding of [ 125 I]‐hrIL‐1β is observed when the murine IL‐1 receptor accessory protein (mIL‐1RAcP) is coexpressed with mIL‐1RII. Binding of [ 125 I]‐hrIL‐1β to mIL‐1RII‐mIL‐1RAcP complex can be inhibited either with antibodies to mIL‐1RII (mAb 4E2), or by antibodies to mIL‐1RAcP (mAb 4C5). The number of high affinity binding sites in cells stably transfected with the cDNA for mIL‐1RII is dependent on the dose of cDNA for mIL‐1RAcP used to transfect the cells. The high affinity complex between mIL‐1RII and mIL‐1RAcP is not preformed by interaction between the intracellular domains of these two transmembrane proteins, rather it appears to require the extracellular portions of mIL‐1RII and mIL‐1RAcP and the presence of a ligand. We suggest that in addition to its earlier described decoy receptor role, IL‐1RII may modulate the responsiveness of cells to IL‐1 by binding the IL‐1RAcP in unproductive/non‐signalling complexes and thus reducing the number of signalling IL‐1RI‐IL‐1RAcP‐agonist complexes when IL‐1 is bound.