Characterization of the human granulocyte-macrophage colony-stimulating factor receptor.

J Dipersio,P Billing,S Kaufman,P Eghtesady,R E Williams,J C Gasson

doi:10.1016/s0021-9258(19)77952-6

Abstract

Human granulocyte-macrophage colony-stimulating factor (GM-CSF) is a cytokine derived from activated T cells, endothelial cells, fibroblasts, and macrophages. It stimulates myeloid and erythroid progenitors to form colonies in semisolid medium in vitro, as well as enhancing multiple differentiated functions of mature neutrophils, macrophages, and eosinophils. We have examined the binding of human GM-CSF to a variety of responsive human cells and cell lines. The most mature myelomonocytic cells, specifically human neutrophils, macrophages, and eosinophils, express the highest numbers of a single class of high affinity receptors (Kd approximately 37 pM, 293-1000 sites/cell). HL-60 and KG-1 cells exhibit an increase in specific binding at high concentrations of GM-CSF; computer analysis of the data is nonetheless consistent with a single class of high affinity binding sites with a Kd approximately 43 pM and 20-450 sites/cell. Dimethyl sulfoxide induces a 3-10-fold increase in high affinity receptors expressed in HL-60 cells, coincident with terminal neutrophilic differentiation. Finally, binding of 125I-GM-CSF to fresh peripheral blood cells from six patients with chronic myelogenous leukemia was analyzed. In three of six cases, binding was similar to the nonsaturable binding observed with HL-60 and KG-1 cells. GM-CSF binding was low, or in some cases, undetectable on myeloblasts obtained from eight patients with acute myelogenous leukemia. The observed affinities of the receptor for GM-CSF are consistent with all known biological activities. Affinity labeling of both normal neutrophils and dimethyl sulfoxide-induced HL-60 cells with unglycosylated 125I-GM-CSF yielded a band of 98 kDa, implying a molecular weight of approximately 84,000 for the human GM-CSF receptor.

Highlights

From the Division of Hematology-Oncology, Department of Medicine,UCLA School of Medicine and $Departmenotf Microbiology, Molecular Biology Institute, UCLA, Los Angeles, California 90024
Cross-linking'"I-GM-CSFtoNormal Human Neutrophils and functional activities [1,2,3,4,5,6,7,8,9,10].We were interested in comparing Me,SO-induced HL-60 Cells: Immunoprecipitation of lZ5Z-GM- the number of GM-CSF receptors on these three types of CSFReceptor Complex peripheral blood cells as well as the presence or absence of Peripheral blood neutrophils were isolated from normal donors low affinity binding sites
There are no known biological effects on human neutrophils, bone marrow CFU-GM, or cell lines which are increased or initiated at concentrations of GM-CSF in excess of 100 PM. Consistent with these observations are theresults presented inthis paper, which clearly demonstrate the presence of high affinity binding sites on normal neutrophils, eosinophils, and human bone marrow

Summary

Introduction

Cross-linking'"I-GM-CSFtoNormal Human Neutrophils and functional activities [1,2,3,4,5,6,7,8,9,10].We were interested in comparing Me,SO-induced HL-60 Cells: Immunoprecipitation of lZ5Z-GM- the number of GM-CSF receptors on these three types of CSFReceptor Complex peripheral blood cells as well as the presence or absence of Peripheral blood neutrophils were isolated from normal donors low affinity binding sites. Saturable binding (data not shown),witha low number of Characterization of the Human GM-CSF Receptor high affinity sites (Table I).

Results

Conclusion