Interleukin-4 (IL-4) and IL-13 bind to a shared heterodimeric complex on endothelial cells mediating vascular cell adhesion molecule-1 induction in the absence of the common gamma chain.

摘要: Interleukin-4 (IL-4) and IL-13 exert similar, nonadditive effects on endothelial cells, inducing vascular cell adhesion molecule-1 (VCAM-1) expression subsequent transmigration of eosinophils. The receptor for IL-4 was described as a shared heteromultimeric complex in which the common gamma-chain (gamma c) subunit essential activity. Endothelial bound both cytokines with high affinity; by flow cytofluorometry reverse transcription-polymerase chain reaction (RT-PCR), they expressed alpha (IL-4R alpha) but did not express gamma c IL-2R. Radioligand cross-linking experiments followed immunoprecipitation monoclonal antibody (MoAb) S697 to IL-4R showed IL-4-specific binding at 130 kD, alpha, minor extent double band coimmunoprecipitated 65 75 kD. [125 I]IL-13 predominantly 65- 75- kD trace amount However, no ligand-cross-linked precipitated MoAb S697, indicating cognate novel IL-13-binding subunit. Excess unlabeled completely displaced binding. Similarly, nonsignaling (Y124D)-mutant abolished IL-4- IL-13-mediated signal transduction. Unlabeled competed successfully unable displace Il-4 from its alpha. TUGh4, specific c, failed precipitate IL-13R. Therefore, structure functional receptors human cells does use or require