scholarly journals Involvement of tyrosine kinases in the activation of human peripheral blood neutrophils by granulocyte-macrophage colony-stimulating factor

Blood ◽  
1991 ◽  
Vol 78 (7) ◽  
pp. 1842-1852 ◽  
Author(s):  
SR McColl ◽  
JF DiPersio ◽  
AC Caon ◽  
P Ho ◽  
PH Naccache

Abstract The aim of the present study is to evaluate the involvement of human neutrophil tyrosine kinase(s) in the signal transduction mechanism of granulocyte-macrophage colony-stimulating factor (GM-CSF). Stimulation of neutrophils with GM-CSF resulted in a time- and dose-dependent phosphorylation of several proteins having estimated molecular weights of approximately 40, 55, 74, 97, 118, and 155 Kd, detected by immunoblot using a monoclonal antibody directed against phosphotyrosine. GM-CSF-induced tyrosine phosphorylation was inhibited in a dose- and time-dependent manner by the tyrosine kinase inhibitor erbstatin. Using this inhibitor, we were able to correlate tyrosine phosphorylation with several functional effects of GM-CSF on human neutrophils. Pretreatment of neutrophils with erbstatin before incubation with GM-CSF completely inhibited the GM-CSF-induced intracellular alkalinization, downregulation of the leukotriene B4 receptor, enhancement of fMet-Leu-Phe-induced intracellular calcium mobilization, as well as the accumulation of mRNA for the proto- oncogene c-fos. Taken together, these data suggest that tyrosine kinase activation in human neutrophils plays a critical regulatory role in both the stimulation and priming of neutrophil function by GM-CSF.

Blood ◽  
1991 ◽  
Vol 78 (7) ◽  
pp. 1842-1852
Author(s):  
SR McColl ◽  
JF DiPersio ◽  
AC Caon ◽  
P Ho ◽  
PH Naccache

The aim of the present study is to evaluate the involvement of human neutrophil tyrosine kinase(s) in the signal transduction mechanism of granulocyte-macrophage colony-stimulating factor (GM-CSF). Stimulation of neutrophils with GM-CSF resulted in a time- and dose-dependent phosphorylation of several proteins having estimated molecular weights of approximately 40, 55, 74, 97, 118, and 155 Kd, detected by immunoblot using a monoclonal antibody directed against phosphotyrosine. GM-CSF-induced tyrosine phosphorylation was inhibited in a dose- and time-dependent manner by the tyrosine kinase inhibitor erbstatin. Using this inhibitor, we were able to correlate tyrosine phosphorylation with several functional effects of GM-CSF on human neutrophils. Pretreatment of neutrophils with erbstatin before incubation with GM-CSF completely inhibited the GM-CSF-induced intracellular alkalinization, downregulation of the leukotriene B4 receptor, enhancement of fMet-Leu-Phe-induced intracellular calcium mobilization, as well as the accumulation of mRNA for the proto- oncogene c-fos. Taken together, these data suggest that tyrosine kinase activation in human neutrophils plays a critical regulatory role in both the stimulation and priming of neutrophil function by GM-CSF.


Blood ◽  
1992 ◽  
Vol 79 (9) ◽  
pp. 2446-2454
Author(s):  
RL Berkow

Human neutrophils treated with chemotactic peptides or phorbol esters demonstrate tyrosine phosphorylation of a subset of proteins. Granulocyte-macrophage colony-stimulating factor (GM-CSF) induced a time- and concentration-dependent increase in the tyrosine phosphorylation of at least seven proteins. Three of these proteins with approximate molecular weights of 150, 95, and 70 Kd were unique to neutrophils treated with GM-CSF, and were not seen to be phosphorylated on tyrosine in neutrophils treated with the agonists FMLP or PMA, or the cytokines G-CSF and tumor necrosis factor. We found the 150-Kd protein to be localized within the cell particulate fraction and the 95- Kd protein within the cell cytosol. The 70-Kd phosphotyrosine protein was found in both fractions. When the neutrophils were treated with Triton X-100 (Sigma Chemical Co, St Louis, MO) to evaluate cytoskeletal associations of proteins, the 150 phosphotyrosine protein partitioned with the Triton X-100 insoluble cytoskeleton (TICS), and the 70-Kd protein partitioned with both the TICS and Triton X-100 soluble proteins. The GM-CSF-induced tyrosine phosphorylation was inhibited by the tyrosine kinase inhibitor ST638. This was not seen with the putative C-kinase inhibitor, H-7. However, staurosporine was seen to inhibit tyrosine phosphorylation of neutrophil proteins by GM-CSF and in vitro tyrosine kinase activity of isolated neutrophil cytosol and particulate fractions. These data indicate that the three unique GM-CSF- induced phosphotyrosine-containing proteins may be responsible for the unique actions of GM-CSF and that staurosporine inhibits a tyrosine kinase responsible for the phosphorylation of these proteins.


Blood ◽  
1992 ◽  
Vol 79 (9) ◽  
pp. 2446-2454 ◽  
Author(s):  
RL Berkow

Abstract Human neutrophils treated with chemotactic peptides or phorbol esters demonstrate tyrosine phosphorylation of a subset of proteins. Granulocyte-macrophage colony-stimulating factor (GM-CSF) induced a time- and concentration-dependent increase in the tyrosine phosphorylation of at least seven proteins. Three of these proteins with approximate molecular weights of 150, 95, and 70 Kd were unique to neutrophils treated with GM-CSF, and were not seen to be phosphorylated on tyrosine in neutrophils treated with the agonists FMLP or PMA, or the cytokines G-CSF and tumor necrosis factor. We found the 150-Kd protein to be localized within the cell particulate fraction and the 95- Kd protein within the cell cytosol. The 70-Kd phosphotyrosine protein was found in both fractions. When the neutrophils were treated with Triton X-100 (Sigma Chemical Co, St Louis, MO) to evaluate cytoskeletal associations of proteins, the 150 phosphotyrosine protein partitioned with the Triton X-100 insoluble cytoskeleton (TICS), and the 70-Kd protein partitioned with both the TICS and Triton X-100 soluble proteins. The GM-CSF-induced tyrosine phosphorylation was inhibited by the tyrosine kinase inhibitor ST638. This was not seen with the putative C-kinase inhibitor, H-7. However, staurosporine was seen to inhibit tyrosine phosphorylation of neutrophil proteins by GM-CSF and in vitro tyrosine kinase activity of isolated neutrophil cytosol and particulate fractions. These data indicate that the three unique GM-CSF- induced phosphotyrosine-containing proteins may be responsible for the unique actions of GM-CSF and that staurosporine inhibits a tyrosine kinase responsible for the phosphorylation of these proteins.


Blood ◽  
1994 ◽  
Vol 84 (1) ◽  
pp. 94-103
Author(s):  
D Linnekin ◽  
OM Howard ◽  
L Park ◽  
W Farrar ◽  
D Ferris ◽  
...  

The human myeloid cell line HL-60 expresses approximately 300 high- affinity granulocyte-macrophage colony-stimulating factor receptors (GM- CSFRs), yet treatment of these cells with GM-CSF does not result in enhanced cellular proliferation or increases in protein tyrosine phosphorylation. In contrast, GM-CSF induces rapid increases in protein tyrosine phosphorylation and proliferative responses in HL-60 cells pretreated for 3 days in dimethyl sulfoxide (DMSO). Similarly, HL-60 cells pretreated with retinoic acid or 1,25 dihydroxyvitamin D3 were also capable of responding to GM-CSF. Interestingly, each of these treatments resulted in increased expression of the src-like tyrosine kinase hck. Stimulation with GM-CSF increased hck autophosphorylation in DMSO-treated HL-60 cells, suggesting that hck is a component of the GM-CSF signal transduction pathway. To determine if hck has a role in the DMSO-induced recoupling of the GM-CSFR, we overexpressed hck in HL- 60 cells. The resulting cell line (HL-60/hck) expresses hck mRNA and protein at levels comparable with DMSO-treated HL-60 cells. Stimulation of HL-60/hck cells with GM-CSF results in activation of hck, increases in protein tyrosine phosphorylation, and increased proliferation. These results show that cytokine receptors can exist in an uncoupled form and suggest that in HL-60 cells, appropriate levels of the src-like tyrosine kinase hck are critical for functional coupling of the GM-CSFR to biologic responses.


Blood ◽  
1992 ◽  
Vol 79 (12) ◽  
pp. 3350-3354 ◽  
Author(s):  
MA Raines ◽  
DW Golde ◽  
M Daeipour ◽  
AE Nel

Receptors of the hematopoietin superfamily, including the granulocyte- macrophage colony-stimulating factor (GM-CSF) receptor, lack a tyrosine kinase domain as well as other sequences indicative of a known signaling mechanism. In this report, we identify the serine/threonine kinase, microtubule-associated protein 2 (MAP2) kinase, as an intermediate in the GM-CSF signal transduction pathway. Treatment of peripheral blood neutrophils or terminally differentiated HL-60 cells with GM-CSF induced a rapid and dose-dependent increase in MAP2 kinase activity. Maximal activity occurred within 5 minutes and the kinetics of the response varied depending on the target cell (prolonged in neutrophils and transient in neutrophilic HL-60 cells). MAP2 kinase activity in these cells correlates with the induction of a 42-Kd tyrosine phosphoprotein. Furthermore, tyrosine phosphorylation is necessary for MAP2 kinase activation since its activity is inhibited by treatment with the tyrosine kinase inhibitor, erbstatin analog. These data suggest that tyrosine phosphorylation is important in GM-CSF- mediated signal transduction and that MAP2 kinase activation may be a central biochemical event involved in its signaling.


Blood ◽  
1994 ◽  
Vol 84 (1) ◽  
pp. 94-103 ◽  
Author(s):  
D Linnekin ◽  
OM Howard ◽  
L Park ◽  
W Farrar ◽  
D Ferris ◽  
...  

Abstract The human myeloid cell line HL-60 expresses approximately 300 high- affinity granulocyte-macrophage colony-stimulating factor receptors (GM- CSFRs), yet treatment of these cells with GM-CSF does not result in enhanced cellular proliferation or increases in protein tyrosine phosphorylation. In contrast, GM-CSF induces rapid increases in protein tyrosine phosphorylation and proliferative responses in HL-60 cells pretreated for 3 days in dimethyl sulfoxide (DMSO). Similarly, HL-60 cells pretreated with retinoic acid or 1,25 dihydroxyvitamin D3 were also capable of responding to GM-CSF. Interestingly, each of these treatments resulted in increased expression of the src-like tyrosine kinase hck. Stimulation with GM-CSF increased hck autophosphorylation in DMSO-treated HL-60 cells, suggesting that hck is a component of the GM-CSF signal transduction pathway. To determine if hck has a role in the DMSO-induced recoupling of the GM-CSFR, we overexpressed hck in HL- 60 cells. The resulting cell line (HL-60/hck) expresses hck mRNA and protein at levels comparable with DMSO-treated HL-60 cells. Stimulation of HL-60/hck cells with GM-CSF results in activation of hck, increases in protein tyrosine phosphorylation, and increased proliferation. These results show that cytokine receptors can exist in an uncoupled form and suggest that in HL-60 cells, appropriate levels of the src-like tyrosine kinase hck are critical for functional coupling of the GM-CSFR to biologic responses.


1994 ◽  
Vol 179 (4) ◽  
pp. 1225-1232 ◽  
Author(s):  
M Pouliot ◽  
P P McDonald ◽  
P Borgeat ◽  
S R McColl

The synthesis of leukotrienes in human blood neutrophils chiefly relies on the activity of two enzymes, phospholipase A2 and 5-lipoxygenase (5-LO). In turn, the activation of the 5-LO requires the participation of a recently characterized membrane-bound protein, the 5-LO-activating protein (FLAP). In this study, we have investigated conditions under which FLAP expression in neutrophils may be modulated. Of several cytokines tested, only granulocyte/macrophage colony-stimulating factor (GM-CSF) (and to a lesser extent tumor necrosis factor alpha) significantly increased expression of FLAP. GM-CSF increased FLAP mRNA steady-state levels in a time- and dose-dependent manner. The stimulatory effect of GM-CSF on FLAP mRNA was inhibited by prior treatment of the cells with the transcription inhibitor, actinomycin D, and pretreatment of the cells with the protein synthesis inhibitor, cycloheximide, failed to prevent the increase in FLAP mRNA induced by GM-CSF. The accumulation of newly synthesized FLAP, as determined by immunoprecipitation after incorporation of 35S-labeled amino acids, was also increased after incubation of neutrophils with GM-CSF. In addition, the total level of FLAP protein was increased in GM-CSF-treated neutrophils, as determined by two-dimensional gel electrophoresis, followed by Western blot. GM-CSF did not alter the stability of the FLAP protein, indicating that the effect of GM-CSF on FLAP accumulation was the consequence of increased de novo synthesis as opposed to decreased degradation of FLAP. Finally, incubation of neutrophils with the synthetic glucocorticoid dexamethasone directly stimulated the upregulation of FLAP mRNA and protein, and enhanced the effect of GM-CSF. Taken together, these data demonstrate that FLAP expression may be upmodulated after appropriate stimulation of neutrophils. The increase in FLAP expression induced by GM-CSF in inflammatory conditions could confer upon neutrophils a prolonged capacity to synthesize leukotrienes.


Blood ◽  
1992 ◽  
Vol 79 (12) ◽  
pp. 3350-3354 ◽  
Author(s):  
MA Raines ◽  
DW Golde ◽  
M Daeipour ◽  
AE Nel

Abstract Receptors of the hematopoietin superfamily, including the granulocyte- macrophage colony-stimulating factor (GM-CSF) receptor, lack a tyrosine kinase domain as well as other sequences indicative of a known signaling mechanism. In this report, we identify the serine/threonine kinase, microtubule-associated protein 2 (MAP2) kinase, as an intermediate in the GM-CSF signal transduction pathway. Treatment of peripheral blood neutrophils or terminally differentiated HL-60 cells with GM-CSF induced a rapid and dose-dependent increase in MAP2 kinase activity. Maximal activity occurred within 5 minutes and the kinetics of the response varied depending on the target cell (prolonged in neutrophils and transient in neutrophilic HL-60 cells). MAP2 kinase activity in these cells correlates with the induction of a 42-Kd tyrosine phosphoprotein. Furthermore, tyrosine phosphorylation is necessary for MAP2 kinase activation since its activity is inhibited by treatment with the tyrosine kinase inhibitor, erbstatin analog. These data suggest that tyrosine phosphorylation is important in GM-CSF- mediated signal transduction and that MAP2 kinase activation may be a central biochemical event involved in its signaling.


Blood ◽  
1996 ◽  
Vol 88 (4) ◽  
pp. 1206-1214 ◽  
Author(s):  
RL Rosen ◽  
KD Winestock ◽  
G Chen ◽  
X Liu ◽  
L Hennighausen ◽  
...  

Granulocyte-macrophage colony-stimulating factor (GM-CSF) induces immediate effects in monocytes by activation of the Janus kinase (JAK2) and STAT transcription factor (STAT5) pathway. Recent studies have identified homologues of STAT5, STAT5A, and STAT5B, as well as lower molecular weight variants of STAT5. To define the activation of the STAT5 homologues and lower molecular weight variant in human monocytes and monocytes differentiated into macrophages by culture in macrophage- CSF (M-CSF), we measured the GM-CSF induced tyrosine phosphorylation of STAT5A, STAT5B, and any lower molecular weight STAT5 isoforms. Freshly isolated monocytes expressed 94-kD STAT5A, 92-kD STAT5B, and an 80-kD STAT5A molecule. Whereas 94-kD STAT5A was clearly tyrosine phosphorylated and bound to the enhancer element, the gamma response region (GRR), of the Fc gamma RI gene, substantially less tyrosine phosphorylated STAT5B bound to the immobilized GRR element. Macrophages lost their ability to express the 80-kD STAT5A protein, but retained their ability to activate STAT5A. STAT5A-STAT5A homodimers and STAT5A- STAT5B heterodimers formed in response to GM-CSF. Therefore, activation of STAT5A predominates compared to STAT5B when assayed by direct immunoprecipitation and by evaluation of bound STATs to immobilized GRR. Selective activation of STAT5 homologues in addition to generation of lower molecular isoforms may provide specificity and control to genes expressed in response to cytokines such as GM-CSF.


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