Involvement of guanine nucleotide binding proteins in neutrophil activation and priming by GM-CSF

Abstract

Pre-incubation of human neutrophils with pertussis toxin significantly inhibited the neutrophil-directed biologic actions of granulocyte- macrophage colony-stimulating factor (GM-CSF) in three separate assays: the induction of c-fos mRNA, the enhancement of both platelet- activating factor-induced mobilization of intracellular calcium, and stimulation of leukotriene synthesis by the calcium ionophore A23187. Cholera toxin did not have an effect on the latter two assays. Pre- treatment of human neutrophils with pertussis toxin did not affect the binding of GM-CSF to its surface receptor. These results provide the first evidence that a pertussis toxin substrate plays an important mediatory role in the mechanism of action of GM-CSF.

The regulation of neutrophil phospholipase A2 by granulocyte‐macrophage colony‐stimulating factor and its role in priming superoxide production

“…We showed that PT did not inhibit the priming of PLA 2 by GM-CSF, indicating that a PT-sensitive heterotrimeric G-protein, such as Gi, was not involved. Our data are in accord with those of DiPersio et al (1988), who found no effect of PT on GM-CSF-mediated priming of leukotriene production, but contrast with other studies (Gomez-Cambronero et al, 1989;Corey & Rossoff, 1989;McColl et al, 1989), showing that other effects of GM-CSF were inhibited by PT. Whilst the PLA 2 activity of unprimed cells was not inhibited by genestein, in confirmation of previous work (Atluru et al, 1992), it specifically blocked the GM-CSF primed response, suggesting the involvement of a tyrosine kinase in the GM-CSF-mediated Phospholipase A 2 and Neutrophil Priming # 1996 Blackwell Science Ltd, British Journal of Haematology 92: 804-814 priming of PLA 2 .…”

“…Role of a Bordatella pertussis toxin sensitive G-protein. It was previously reported that effects of GM-CSF in several systems is regulated by a Bordatella pertussis toxin sensitive GTPbinding protein (G protein) (Gomez-Cambronero et al, 1989;Corey & Rossoff, 1989;McColl et al, 1989) although other workers found no such effect (DiPersio et al, 1988). To investigate whether pertussis toxin (PT) inhibited GM-CSFmediated priming of PLA 2 , neutrophils were preincubated with concentrations of PT that ranged from 0 to 1 g/ml for 90 min before addition of GM-CSF or diluent followed by stimulation with calcium ionophore (A23187) and measurement of AA release.…”

Granulocyte macrophage-colony stimulating factor stimulates both association and activation of phosphoinositide 3OH-kinase and src-related tyrosine kinase(s) in human myeloid derived cells.

“…Several features of this response suggest that, unlike many reported effects of GM-CSF on signalling reactions (e.g. Corey and Rossoff, 1989;McColl et al, 1989) in Ptdlns(3,4,5)P3 (lower panels) or Ptdlns(4,5)P2 (upper panels), the ranges of the individual data points are indicated by error bars. The data for neutrophils incubated with or without staurosporine were reproduced in one further experiment for GM-CSF and three further experiments for FMLP.…”

In vitro – transcriptional response of polymorphonuclear leukocytes following contact with different antigens

“…In PMN performing 'frustrated' phagocytosis we did not find significant differences in the NF-κB pathway, however, FOS and JUN (the proteins c-fos and c-jun form the transcriptional regulator AP-1) were both increasingly expressed. PMN have been reported to constitutively express family members of FOS and JUN on transcriptional as well as c-fos and c-jun on translational level [32][33][34][35] with the steady state level of their RNA transcripts being rapidly up-regulated in response to several stimuli [36,37]. However, neither the proteins c-jun and c-fos nor the protein AP-1 has been shown to be up-regulated in PMN after exposure to diverse stimuli as indicated by our results and as reported by others [34,35].…”