Expression and modulation of IL-3 and GM-CSF receptors in human growth factor dependent leukaemic cells.
From the interleukin-3 (IL-3) responsive human myeloid cell line M-07 we derived a subclone, named M-07e, which is fully dependent for growth and survival on either granulocyte-macrophage colony stimulating factor (GM-CSF) or IL-3. In this paper the expression, specificity and modulation of GM-CSF and IL-3 receptors on M-07e cells are described. The specificity of the binding was demonstrated by the failure of other cytokines to compete, at 4 degrees C, with GM-CSF or IL-3 receptors. In addition, IL-3 was found to compete as well as GM-CSF for GM-CSF receptors while GM-CSF was a weak competitor for IL-3 receptors. Quantitative binding studies and Scatchard plot analysis revealed the presence of a single class of high-affinity GM-CSF binding sites (405 +/- 27.4 sites per cell, dissociation constant at the equilibrium 52 +/- 20 pM) and the presence of high and low-affinity regions for IL-3 binding sites (27 +/- 12 and 416 +/- 92 sites per cell for the high and low affinity regions respectively, dissociation constant at the equilibrium, 58 +/- 22 pM and 5.7 +/- 2.0 nM respectively). Finally, in agreement with the hierarchical down-modulation model, we found that IL-3 can down-modulate both IL-3 and GM-CSF receptors while GM-CSF can down-modulate only its own receptors. The present results suggest that M-07e cells, in spite of their neoplastic nature, share, with murine bone marrow cells, similar growth factor receptor regulatory mechanisms. This cell line may be regarded as a candidate model to investigate the physiological events triggered by growth factors binding to human haemopoietic cells.
Brizzi
M F
MF
Istituto di Medicina Interna, Universitá di Torino, Italy.
Avanzi
G C
GC
Veglia
F
F
Clark
S C
SC
Pegoraro
L
L
D002460:Cell Line; D004261:DNA Replication / Q000187:drug effects; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000378:metabolism* / Q000494:pharmacology; D006133:Growth Substances / Q000494:pharmacology*; D006801:Humans; D007377:Interleukin-3 / Q000378:metabolism* / Q000494:pharmacology; D007700:Kinetics; D007938:Leukemia; D016187:Receptors, Granulocyte-Macrophage Colony-Stimulating Factor / Q000096:biosynthesis / Q000378:metabolism*; D016185:Receptors, Interleukin-3 / Q000096:biosynthesis / Q000378:metabolism*; D013816:Thermodynamics
D006133:Growth Substances; D007377:Interleukin-3; D016187:Receptors, Granulocyte-Macrophage Colony-Stimulating Factor; D016185:Receptors, Interleukin-3; D016178:Granulocyte-Macrophage Colony-Stimulating Factor