Human myeloid cells possessing high-affinity receptors for granulocyte-macrophage colony stimulating factor

Granulocyte-macrophage colony-stimulating factor (GM-CSF) plays a critical role in growth and differentiation of myeloid cells. We previously reconstituted high-affinity human GM-CSF receptor (hGM-CSFR) in a pro-B cell line, BA/F3, by cotransfecting alpha- and beta-chain cDNA clones and showed that the reconstituted receptor could transduce growth-promoting signals. The high-affinity hGM-CSFR was also reconstituted in mouse NIH 3T3 cells, but its ability to transduce signals in fibroblasts remained undetermined. In the present study, we further characterized signal transduction by the reconstituted hGM-CSFR in both NIH 3T3 cells and BA/F3 cells. We found that the reconstituted hGM-CSFR transduces signals in NIH 3T3 fibroblasts and BA/F3 cells in response to hGM-CSF to activate transcription of the c-fos, c-jun, and c-myc proto-oncogenes. hGM-CSF also induces protein tyrosine phosphorylation and DNA synthesis in both cell types. These results indicated that hGM-CSFR is functional in fibroblasts, that signal transduction via hGM-CSFR in fibroblasts involves tyrosine kinase(s), and that association of hGM-CSFR with a factor(s) specific to hematopoietic cell lineage is not essential to transduce growth-promoting signals.

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A Truncated Isoform of the Human β Chain Common to the Receptors for Granulocyte-Macrophage Colony-Stimulating Factor, Interleukin-3 (IL-3), and IL-5 With Increased mRNA Expression in Some Patients With Acute Leukemia

Blood ◽

10.1182/blood.v91.1.54.54_54_63 ◽

1998 ◽

Vol 91 (1) ◽

pp. 54-63 ◽

Cited By ~ 4

Author(s):

Rosemary E. Gale ◽

Robin W. Freeburn ◽

Asim Khwaja ◽

Rajesh Chopra ◽

David C. Linch

Keyword(s):

Amino Acids ◽

Acute Leukemia ◽

Myeloid Cells ◽

Colony Stimulating Factor ◽

Interleukin 3 ◽

Gm Csf ◽

Macrophage Colony Stimulating Factor ◽

Macrophage Colony ◽

Β Chain ◽

Stimulating Factor

We report here a naturally occurring isoform of the human β chain common to the receptors for granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and IL-5 (GMRβC) with a truncated intracytoplasmic tail caused by deletion of a 104-bp exon in the membrane-proximal region of the chain. This β intracytoplasmic truncated chain (βIT) has a predicted tail of 46 amino acids, instead of 432 for βC, with 23 amino acids in common with βC and then a new sequence of 23 amino acids. In primary myeloid cells, βIT comprised approximately 20% of the total β chain message, but was increased up to 90% of total in blast cells from a significant proportion of patients with acute leukemia. Specific anti-βITantibodies demonstrated its presence in primary myeloid cells and cell lines. Coexpression of βIT converted low-affinity GMRα chains (KD 2.5 nmol/L) to higher-affinity αβ complexes (KD 200 pmol/L). These could bind JAK2 that was tyrosine-phosphorylated by stimulation with GM-CSF. βITdid not support GM-CSF–induced proliferation when cotransfected with GMRα into CTLL-2 cells. Therefore, it may interfere with the signal-transducing properties of the βC chain and play a role in the pathogenesis of leukemia.

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Differential activation of leukotriene biosynthesis by granulocyte- macrophage colony-stimulating factor and interleukin-5 in an eosinophilic substrain of HL-60 cells

Blood ◽

10.1182/blood.v86.9.3507.bloodjournal8693507 ◽

1995 ◽

Vol 86 (9) ◽

pp. 3507-3516 ◽

Cited By ~ 10

Author(s):

KA Scoggan ◽

AW Ford-Hutchinson ◽

DW Nicholson

Keyword(s):

Binding Sites ◽

Affinity Binding ◽

Colony Stimulating Factor ◽

High Affinity Binding ◽

Interleukin 5 ◽

Gm Csf ◽

High Affinity ◽

Macrophage Colony Stimulating Factor ◽

Macrophage Colony ◽

Stimulating Factor

Cytokines can stimulate eosinophils to produce cysteinyl leukotrienes (LTs) in the lung that provoke tissue destruction associated with asthma. Priming of an eosinophilic substrain of HL-60 cells (HL-60#7) with recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) before ionophore challenge was found to produce an apparent 45% increase in total LT production in a dose-dependent manner (ED50 = 150 pmol/L) that could be accounted for by a decrease in the time required for maximal formation of LTs. GM-CSF had no effect on the kinetic parameters of LTC4 synthase and therefore probably acts upstream of this catalytic event. Incubation with interleukin-5 (IL-5), however, had no effect on LT biosynthesis. This differential priming ability was not a consequence of different receptor populations or differences in the affinity or stability of the ligand-receptor complexes of GM-CSF and IL-5. GM-CSF and IL-5 each displayed similar populations of high-affinity binding sites and neither GM-CSF nor IL-5 were able to cross-compete for the other's receptor binding sites. Analysis of phosphotyrosine patterns suggest that IL-5 is incapable of transducing a signal in eosinophilic HL-60#7 cells even though IL-5 and GM-CSF receptors mediate signal transduction via a common beta-chain component that is also necessary for high-affinity binding. Overall, this unique system may permit the dissection of distinct events responsible for specific intracellular signals transduced separately by GM-CSF or IL-5.

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Simultaneous Antagonism of Interleukin-5, Granulocyte-Macrophage Colony-Stimulating Factor, and Interleukin-3 Stimulation of Human Eosinophils by Targetting the Common Cytokine Binding Site of Their Receptors

Blood ◽

10.1182/blood.v94.6.1943 ◽

1999 ◽

Vol 94 (6) ◽

pp. 1943-1951 ◽

Cited By ~ 46

Author(s):

Q. Sun ◽

K. Jones ◽

B. McClure ◽

B. Cambareri ◽

B. Zacharakis ◽

...

Keyword(s):

Affinity Binding ◽

Colony Stimulating Factor ◽

High Affinity Binding ◽

Receptor Dimerization ◽

Interleukin 5 ◽

Gm Csf ◽

High Affinity ◽

Macrophage Colony Stimulating Factor ◽

Macrophage Colony ◽

Stimulating Factor

Abstract Human interleukin-5 (IL-5), granulocyte-macrophage colony-stimulating factor (GM-CSF), and IL-3 are eosinophilopoietic cytokines implicated in allergy in general and in the inflammation of the airways specifically as seen in asthma. All 3 cytokines function through cell surface receptors that comprise a ligand-specific  chain and a shared subunit (βc). Although binding of IL-5, GM-CSF, and IL-3 to their respective receptor  chains is the first step in receptor activation, it is the recruitment of βc that allows high-affinity binding and signal transduction to proceed. Thus, βc is a valid yet untested target for antiasthma drugs with the added advantage of potentially allowing antagonism of all 3 eosinophil-acting cytokines with a single compound. We show here the first development of such an agent in the form of a monoclonal antibody (MoAb), BION-1, raised against the isolated membrane proximal domain of βc. BION-1 blocked eosinophil production, survival, and activation stimulated by IL-5 as well as by GM-CSF and IL-3. Studies of the mechanism of this antagonism showed that BION-1 prevented the high-affinity binding of125I–IL-5, 125I–GM-CSF, and125I–IL-3 to purified human eosinophils and that it bound to the major cytokine binding site of βc. Interestingly, epitope analysis using several βc mutants showed that BION-1 interacted with residues different from those used by IL-5, GM-CSF, and IL-3. Furthermore, coimmunoprecipitation experiments showed that BION-1 prevented ligand-induced receptor dimerization and phosphorylation of βc, suggesting that ligand contact with βc is a prerequisite for recruitment of βc, receptor dimerization, and consequent activation. These results demonstrate the feasibility of simultaneously inhibiting IL-5, GM-CSF, and IL-3 function with a single agent and that BION-1 represents a new tool and lead compound with which to identify and generate further agents for the treatment of eosinophil-dependent diseases such as asthma.

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A Truncated Isoform of the Human β Chain Common to the Receptors for Granulocyte-Macrophage Colony-Stimulating Factor, Interleukin-3 (IL-3), and IL-5 With Increased mRNA Expression in Some Patients With Acute Leukemia

Blood ◽

10.1182/blood.v91.1.54 ◽

1998 ◽

Vol 91 (1) ◽

pp. 54-63 ◽

Cited By ~ 24

Author(s):

Rosemary E. Gale ◽

Robin W. Freeburn ◽

Asim Khwaja ◽

Rajesh Chopra ◽

David C. Linch

Keyword(s):

Amino Acids ◽

Acute Leukemia ◽

Myeloid Cells ◽

Colony Stimulating Factor ◽

Interleukin 3 ◽

Gm Csf ◽

Macrophage Colony Stimulating Factor ◽

Macrophage Colony ◽

Β Chain ◽

Stimulating Factor

Abstract We report here a naturally occurring isoform of the human β chain common to the receptors for granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and IL-5 (GMRβC) with a truncated intracytoplasmic tail caused by deletion of a 104-bp exon in the membrane-proximal region of the chain. This β intracytoplasmic truncated chain (βIT) has a predicted tail of 46 amino acids, instead of 432 for βC, with 23 amino acids in common with βC and then a new sequence of 23 amino acids. In primary myeloid cells, βIT comprised approximately 20% of the total β chain message, but was increased up to 90% of total in blast cells from a significant proportion of patients with acute leukemia. Specific anti-βITantibodies demonstrated its presence in primary myeloid cells and cell lines. Coexpression of βIT converted low-affinity GMRα chains (KD 2.5 nmol/L) to higher-affinity αβ complexes (KD 200 pmol/L). These could bind JAK2 that was tyrosine-phosphorylated by stimulation with GM-CSF. βITdid not support GM-CSF–induced proliferation when cotransfected with GMRα into CTLL-2 cells. Therefore, it may interfere with the signal-transducing properties of the βC chain and play a role in the pathogenesis of leukemia.

Download Full-text

Simultaneous Antagonism of Interleukin-5, Granulocyte-Macrophage Colony-Stimulating Factor, and Interleukin-3 Stimulation of Human Eosinophils by Targetting the Common Cytokine Binding Site of Their Receptors

Blood ◽

10.1182/blood.v94.6.1943.418k04_1943_1951 ◽

1999 ◽

Vol 94 (6) ◽

pp. 1943-1951 ◽

Cited By ~ 1

Author(s):

Q. Sun ◽

K. Jones ◽

B. McClure ◽

B. Cambareri ◽

B. Zacharakis ◽

...

Keyword(s):

Affinity Binding ◽

Colony Stimulating Factor ◽

High Affinity Binding ◽

Receptor Dimerization ◽

Interleukin 5 ◽

Gm Csf ◽

High Affinity ◽

Macrophage Colony Stimulating Factor ◽

Macrophage Colony ◽

Stimulating Factor

Human interleukin-5 (IL-5), granulocyte-macrophage colony-stimulating factor (GM-CSF), and IL-3 are eosinophilopoietic cytokines implicated in allergy in general and in the inflammation of the airways specifically as seen in asthma. All 3 cytokines function through cell surface receptors that comprise a ligand-specific  chain and a shared subunit (βc). Although binding of IL-5, GM-CSF, and IL-3 to their respective receptor  chains is the first step in receptor activation, it is the recruitment of βc that allows high-affinity binding and signal transduction to proceed. Thus, βc is a valid yet untested target for antiasthma drugs with the added advantage of potentially allowing antagonism of all 3 eosinophil-acting cytokines with a single compound. We show here the first development of such an agent in the form of a monoclonal antibody (MoAb), BION-1, raised against the isolated membrane proximal domain of βc. BION-1 blocked eosinophil production, survival, and activation stimulated by IL-5 as well as by GM-CSF and IL-3. Studies of the mechanism of this antagonism showed that BION-1 prevented the high-affinity binding of125I–IL-5, 125I–GM-CSF, and125I–IL-3 to purified human eosinophils and that it bound to the major cytokine binding site of βc. Interestingly, epitope analysis using several βc mutants showed that BION-1 interacted with residues different from those used by IL-5, GM-CSF, and IL-3. Furthermore, coimmunoprecipitation experiments showed that BION-1 prevented ligand-induced receptor dimerization and phosphorylation of βc, suggesting that ligand contact with βc is a prerequisite for recruitment of βc, receptor dimerization, and consequent activation. These results demonstrate the feasibility of simultaneously inhibiting IL-5, GM-CSF, and IL-3 function with a single agent and that BION-1 represents a new tool and lead compound with which to identify and generate further agents for the treatment of eosinophil-dependent diseases such as asthma.

Download Full-text