scholarly journals Enhancement of neutrophil function by granulocyte-macrophage colony- stimulating factor involves recruitment of a less responsive subpopulation

Blood ◽  
1988 ◽  
Vol 71 (3) ◽  
pp. 652-658 ◽  
Author(s):  
MP Fletcher ◽  
JC Gasson

Abstract Human granulocyte-macrophage colony-stimulating factor (GM-CSF) enhances numerous functions of mature neutrophils (PMN) including phagocytosis, superoxide responses to chemotaxins, antibody-dependent cellular cytotoxicity, and expression of complement receptors. A central question concerns whether the mechanism of enhancement involves quantitative increases in the response of all cells v subpopulation recruitment. The effects of GM-CSF on individual cell light scatter changes, membrane potential, and oxidant responses induced by the chemoattractant N-formyl-methionyl-leucyl-phenylalanine (FMLP) were assessed by flow cytometry and by scoring individual cells for nitroblue tetrazolium dye (NBT) reduction. GM-CSF produced a dose- and time-dependent shift in forward light scatter that was very similar in character to that seen with FMLP or leukotriene B4 stimulation. Although not capable of depolarizing the cells directly, GM-CSF primed PMNs for enhanced membrane potential responses to FMLP by significantly increasing the proportion of depolarizing cells when compared with diluent-treated controls after a 60-minute incubation at 37 degrees C (79.4% +/- 3.4% v 29.5% +/- 4.7% GM-CSF v diluent, mean +/- SE, P less than .005, n = 11). Subpopulation recruitment by GM-CSF treatment was also demonstrated by the FMLP-elicited NBT test. Taken together, these results indicate that GM-CSF can modulate the function of mature PMN by enhancing the proportion of responsive cells.

Blood ◽  
1988 ◽  
Vol 71 (3) ◽  
pp. 652-658
Author(s):  
MP Fletcher ◽  
JC Gasson

Human granulocyte-macrophage colony-stimulating factor (GM-CSF) enhances numerous functions of mature neutrophils (PMN) including phagocytosis, superoxide responses to chemotaxins, antibody-dependent cellular cytotoxicity, and expression of complement receptors. A central question concerns whether the mechanism of enhancement involves quantitative increases in the response of all cells v subpopulation recruitment. The effects of GM-CSF on individual cell light scatter changes, membrane potential, and oxidant responses induced by the chemoattractant N-formyl-methionyl-leucyl-phenylalanine (FMLP) were assessed by flow cytometry and by scoring individual cells for nitroblue tetrazolium dye (NBT) reduction. GM-CSF produced a dose- and time-dependent shift in forward light scatter that was very similar in character to that seen with FMLP or leukotriene B4 stimulation. Although not capable of depolarizing the cells directly, GM-CSF primed PMNs for enhanced membrane potential responses to FMLP by significantly increasing the proportion of depolarizing cells when compared with diluent-treated controls after a 60-minute incubation at 37 degrees C (79.4% +/- 3.4% v 29.5% +/- 4.7% GM-CSF v diluent, mean +/- SE, P less than .005, n = 11). Subpopulation recruitment by GM-CSF treatment was also demonstrated by the FMLP-elicited NBT test. Taken together, these results indicate that GM-CSF can modulate the function of mature PMN by enhancing the proportion of responsive cells.


Blood ◽  
1991 ◽  
Vol 77 (12) ◽  
pp. 2694-2700 ◽  
Author(s):  
RA Warringa ◽  
L Koenderman ◽  
PT Kok ◽  
J Kreukniet ◽  
PL Bruijnzeel

Eosinophilia and eosinophil function are regulated by cytokines such as granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin- 3 (IL-3), and IL-5. We have investigated the modulatory role of GM-CSF and IL-3 on the platelet-activating factor (PAF)-, neutrophil- activating factor (NAF/IL-8)-, leukotriene B4 (LTB4)-, N-formyl- methionyl-leucyl-phenylalanine (FMLP)-, and human complement factor C5a- induced chemotaxis of eosinophils from normal individuals. These eosinophils show a chemotactic response toward PAF, LTB4, and C5a, but not to NAF/IL-8 and FMLP. Preincubation of the eosinophils with picomolar concentrations of GM-CSF caused a significant increase in the response toward LTB4 and induced a significant chemotactic response toward NAF/IL-8 and FMLP. Preincubation of the eosinophils with picomolar concentrations of IL-3 also induced a chemotactic response toward NAF/IL-8 and FMLP, and enhanced the PAF-induced chemotaxis response toward C5a was not influenced by both cytokines. Nanomolar concentrations of GM-CSF or IL-3 caused a significant inhibition of the C5a-induced chemotaxis. The LTB4-induced chemotaxis was also significantly inhibited in case of GM-CSF. At these concentrations both GM-CSF and IL-3 acted as chemotaxins for eosinophils were washed after pretreatment with GM-CSF and IL-3 the potentiation of the chemotactic response remained, whereas the inhibitory mode of action disappeared. Our data indicate that at picomolar concentrations the cytokines GM-CSF and IL-3 can modulate eosinophil chemotaxis and at nanomolar concentrations these cytokines can act as chemotaxins for eosinophils.


2002 ◽  
Vol 13 (2) ◽  
pp. 350-358
Author(s):  
A. Richard Kitching ◽  
Xiao Ru Huang ◽  
Amanda L. Turner ◽  
Peter G. Tipping ◽  
Ashley R. Dunn ◽  
...  

ABSTRACT. Proliferative glomerulonephritis in humans is characterized by the presence of leukocytes in glomeruli. Granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) can potentially stimulate or affect T cell, macrophage, and neutrophil function. To define the roles of GM-CSF and G-CSF in leukocyte-mediated glomerulonephritis, glomerular injury was studied in mice genetically deficient in either GM-CSF (GM-CSF −/− mice) or G-CSF (G-CSF −/− mice). Two models of glomerulonephritis were studied: neutrophil-mediated heterologous-phase anti-glomerular basement membrane (GBM) glomerulonephritis and T cell/macrophage-mediated crescentic autologous-phase anti-GBM glomerulonephritis. Both GM-CSF −/− and G-CSF −/− mice were protected from heterologous-phase anti-GBM glomerulonephritis compared with genetically normal (CSF WT) mice, with reduced proteinuria and glomerular neutrophil numbers. However, only GM-CSF −/− mice were protected from crescentic glomerular injury in the autologous phase, whereas G-CSF −/− mice were not protected and in fact had increased numbers of T cells in glomeruli. Humoral responses to the nephritogenic antigen were unaltered by deficiency of either GM-CSF or G-CSF, but glomerular T cell and macrophage numbers, as well as dermal delayed-type hypersensitivity to the nephritogenic antigen, were reduced in GM-CSF −/− mice. These studies demonstrate that endogenous GM-CSF plays a role in experimental glomerulonephritis in both the autologous and heterologous phases of injury.


Blood ◽  
1991 ◽  
Vol 77 (12) ◽  
pp. 2694-2700 ◽  
Author(s):  
RA Warringa ◽  
L Koenderman ◽  
PT Kok ◽  
J Kreukniet ◽  
PL Bruijnzeel

Abstract Eosinophilia and eosinophil function are regulated by cytokines such as granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin- 3 (IL-3), and IL-5. We have investigated the modulatory role of GM-CSF and IL-3 on the platelet-activating factor (PAF)-, neutrophil- activating factor (NAF/IL-8)-, leukotriene B4 (LTB4)-, N-formyl- methionyl-leucyl-phenylalanine (FMLP)-, and human complement factor C5a- induced chemotaxis of eosinophils from normal individuals. These eosinophils show a chemotactic response toward PAF, LTB4, and C5a, but not to NAF/IL-8 and FMLP. Preincubation of the eosinophils with picomolar concentrations of GM-CSF caused a significant increase in the response toward LTB4 and induced a significant chemotactic response toward NAF/IL-8 and FMLP. Preincubation of the eosinophils with picomolar concentrations of IL-3 also induced a chemotactic response toward NAF/IL-8 and FMLP, and enhanced the PAF-induced chemotaxis response toward C5a was not influenced by both cytokines. Nanomolar concentrations of GM-CSF or IL-3 caused a significant inhibition of the C5a-induced chemotaxis. The LTB4-induced chemotaxis was also significantly inhibited in case of GM-CSF. At these concentrations both GM-CSF and IL-3 acted as chemotaxins for eosinophils were washed after pretreatment with GM-CSF and IL-3 the potentiation of the chemotactic response remained, whereas the inhibitory mode of action disappeared. Our data indicate that at picomolar concentrations the cytokines GM-CSF and IL-3 can modulate eosinophil chemotaxis and at nanomolar concentrations these cytokines can act as chemotaxins for eosinophils.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jani Lappalainen ◽  
Nicolas Yeung ◽  
Su D. Nguyen ◽  
Matti Jauhiainen ◽  
Petri T. Kovanen ◽  
...  

AbstractIn atherosclerotic lesions, blood-derived monocytes differentiate into distinct macrophage subpopulations, and further into cholesterol-filled foam cells under a complex milieu of cytokines, which also contains macrophage-colony stimulating factor (M-CSF) and granulocyte–macrophage-colony stimulating factor (GM-CSF). Here we generated human macrophages in the presence of either M-CSF or GM-CSF to obtain M-MØ and GM-MØ, respectively. The macrophages were converted into cholesterol-loaded foam cells by incubating them with acetyl-LDL, and their atheroinflammatory gene expression profiles were then assessed. Compared with GM-MØ, the M-MØ expressed higher levels of CD36, SRA1, and ACAT1, and also exhibited a greater ability to take up acetyl-LDL, esterify cholesterol, and become converted to foam cells. M-MØ foam cells expressed higher levels of ABCA1 and ABCG1, and, correspondingly, exhibited higher rates of cholesterol efflux to apoA-I and HDL2. Cholesterol loading of M-MØ strongly suppressed the high baseline expression of CCL2, whereas in GM-MØ the low baseline expression CCL2 remained unchanged during cholesterol loading. The expression of TNFA, IL1B, and CXCL8 were reduced in LPS-activated macrophage foam cells of either subtype. In summary, cholesterol loading converged the CSF-dependent expression of key genes related to intracellular cholesterol balance and inflammation. These findings suggest that transformation of CSF-polarized macrophages into foam cells may reduce their atheroinflammatory potential in atherogenesis.


Neonatology ◽  
2021 ◽  
pp. 1-7
Author(s):  
Verena Schulte ◽  
Alexandra Sipol ◽  
Stefan Burdach ◽  
Esther Rieger-Fackeldey

<b><i>Background:</i></b> The granulocyte-macrophage-colony-stimulating factor (GM-CSF) plays an important role in surfactant homeostasis. β<sub>C</sub> is a subunit of the GM-CSF receptor (GM-CSF-R), and its activation mediates surfactant catabolism in the lung. β<sub>IT</sub> is a physiological, truncated isoform of β<sub>C</sub> and is known to act as physiological inhibitor of β<sub>C</sub>. <b><i>Objective:</i></b> The aim of this study was to determine the ratio of β<sub>IT</sub> and β<sub>C</sub> in the peripheral blood of newborns and its association with the degree of respiratory failure at birth. <b><i>Methods:</i></b> We conducted a prospective cohort study in newborns with various degrees of respiratory impairment at birth. Respiratory status was assessed by a score ranging from no respiratory impairment (0) to invasive respiratory support (3). β<sub>IT</sub> and β<sub>C</sub> expression were determined in peripheral blood cells by real-time PCR. β<sub>IT</sub> expression, defined as the ratio of β<sub>IT</sub> and β<sub>C</sub>, was correlated with the respiratory score. <b><i>Results:</i></b> β<sub>IT</sub> expression was found in all 59 recruited newborns with a trend toward higher β<sub>IT</sub> in respiratory ill (score 2, 3) newborns than respiratory healthy newborns ([score 0, 1]; <i>p</i> = 0.066). Seriously ill newborns (score 3) had significantly higher β<sub>IT</sub> than healthy newborns ([score 0], <i>p</i> = 0.010). Healthy preterm infants had significantly higher β<sub>IT</sub> expression than healthy term infants (<i>p</i> = 0.019). <b><i>Conclusions:</i></b> β<sub>IT</sub> is expressed in newborns with higher expression in respiratory ill than respiratory healthy newborns. We hypothesize that β<sub>IT</sub> may have a protective effect in postnatal pulmonary adaptation acting as a physiological inhibitor of β<sub>C</sub> and, therefore, maintaining surfactant in respiratory ill newborns.


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