Interactions of granulocyte-macrophage colony-stimulating factor (CSF), granulocyte CSF, and tumor necrosis factor alpha in the priming of the neutrophil respiratory burst.
Exposure of neutrophils to a range of cytokines augments their response to subsequent agonist-induced activation of the respiratory burst. We have examined the effects of several of these factors, both singly and in combination, on the priming of f-met-leu-phe (FMLP) and complement C5a-stimulated neutrophil H2O2 production, using a whole blood flow cytometric assay designed to minimize artefactual activation. Both granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor alpha (TNF alpha) produced a similar degree of priming of the FMLP-stimulated burst in vitro (558% +/- 86%, n = 41, and 581% +/- 95%, n = 21, of the response seen with FMLP alone, respectively), but with markedly different kinetics (half-maximal response 20 minutes and 7 minutes, respectively). Preincubation with granulocyte colony-stimulating factor (G-CSF) alone caused only modest priming (202% +/- 39%, n = 14). Priming with cytokine combinations of the FMLP-stimulated burst showed that the combinations of G-CSF and TNF alpha and GM-CSF and TNF alpha are highly synergistic, with recruitment of neutrophils unresponsive to priming by single agents. Priming with the combination of GM-CSF and G-CSF was not significantly different to priming with GM-CSF alone. Similar results were obtained using C5a as the respiratory burst stimulus. Significant priming of the FMLP-stimulated respiratory burst was seen in vivo in patients receiving an infusion of GM-CSF (332% +/- 50% of preinfusion response to FMLP, P less than .005, n = 8). Priming was also seen in patients receiving G-CSF (152% +/- 58%, n = 5), although this did not reach conventional significance levels (.05 less than P less than .1). Although GM-CSF infusion caused priming in vivo, this was 48% less than predicted by preinfusion in vitro responses. This result was not due to inadequate GM-CSF levels as addition of further GM-CSF ex vivo did not correct the response. However, these neutrophils were still able to respond appropriately to ex vivo priming with TNF alpha, with a doubling in H2O2 production.
Department of Haematology, University College and Middlesex School of Medicine, London, UK.
A
A
Khwaja
J E
JE
Carver
D C
DC
Linch
D015936:Complement C5a / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D016179:Granulocyte Colony-Stimulating Factor / Q000008:administration & dosage*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000008:administration & dosage*; D006801:Humans; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000502:physiology*; D016897:Respiratory Burst / Q000187:drug effects*; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000008:administration & dosage*
D014409:Tumor Necrosis Factor-alpha; D016179:Granulocyte Colony-Stimulating Factor; D009240:N-Formylmethionine Leucyl-Phenylalanine; D015936:Complement C5a; D016178:Granulocyte-Macrophage Colony-Stimulating Factor