Please use this identifier to cite or link to this item:
Scopus Web of Science® Altmetric
Type: Journal article
Title: Differential binding of IL-3 and GM-CSF to human monocytes
Author: Elliott, M.
Moss, J.
Dottore, M.
Park, L.
Vadas, M.
Lopez, A.
Citation: Growth Factors, 1992; 6(1):15-29
Publisher: Taylor & Francis
Issue Date: 1992
ISSN: 0897-7194
Statement of
Michael J. Elliott, Jennifer Moss, Mara Dottore, Linda S. Park, Mathew A. Vadas, Angel F. Lopez
Abstract: Human monocytes respond to IL-3 and GM-CSF with a similar range of functional activities, and at similar cytokine concentrations. We have recently shown, however, that the rate of monocyte activation is greater in response to GM-CSF than to IL-3. In order to understand the basis of this phenomenon we investigated the interaction of IL-3 and GM-CSF with their surface receptors by means of kinetic binding experiments. 125I-GM-CSF showed very rapid association to monocytes at 37 degrees C, with a half-time of only 40 sec. The pattern of binding with this ligand was complex, with a decline in overall cell-associated radioactivity after 2 min of incubation. In contrast, 125I-IL-3 showed slower association, with a half-time at 37 degrees C of 2.5 min. The different rates of association correlated well with the different rates of cell activation induced by the two cytokines. On the other hand, rates of internalisation were similar for the two cytokines, with half-times of 14-15 min. Competition binding experiments performed under high affinity conditions showed that IL-3 and GM-CSF cross-competed for binding on the surface of monocytes. In contrast, under low affinity conditions IL-3 did not compete for 125I-GM-CSF binding while GM-CSF was a strong competitor of 125I-IL-3 binding. In quantitative inhibition experiments GM-CSF showed inhibitory effects on low affinity 125I-IL-3 binding at lower concentrations than those needed with unlabelled IL-3. It is suggested that current models of IL-3/GM-CSF receptor interactions need to be revised in order to accommodate the unique pattern of competition on human monocytes presented here.
Keywords: Monocytes; Granulocyte-Macrophage Colony-Stimulating Factor; Interleukin-3; Receptors, Colony-Stimulating Factor; Radioligand Assay; Cell Adhesion; Binding, Competitive; Kinetics
Rights: ©1992 Harwood Academic Publishers GmbH
RMID: 0030050948
DOI: 10.3109/08977199209008868
Appears in Collections:Medicine publications

Files in This Item:
There are no files associated with this item.

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.