scholarly journals Activation of NADPH oxidase in human neutrophils permeabilized with Staphylococcus aureus alpha-toxin. A lower Km when the enzyme is activated in situ.

1992 ◽  
Vol 267 (1) ◽  
pp. 323-330
Author(s):  
S A Bauldry ◽  
V N Nasrallah ◽  
D A Bass
Keyword(s):  
Staphylococcus Aureus ◽  
Nadph Oxidase ◽  
Human Neutrophils ◽  
Alpha Toxin ◽  
Toxin A

CD18-dependent activation of the neutrophil NADPH oxidase during phagocytosis of Escherichia coli or Staphylococcus aureus is regulated by class III but not class I or II PI3Ks

Blood ◽  
2008 ◽  
Vol 112 (13) ◽  
pp. 5202-5211 ◽  
Author(s):  
Karen E. Anderson ◽  
Keith B. Boyle ◽  
Keith Davidson ◽  
Tamara A. M. Chessa ◽  
Suhasini Kulkarni ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Nadph Oxidase ◽  
Cell Line ◽  
Microbial Pathogens ◽  
Class I ◽  
Human Neutrophils ◽  
Class Iii ◽  
Single Class ◽  
E Coli

Abstract Phagocytosis and activation of the NADPH oxidase are important mechanisms by which neutrophils and macrophages engulf and kill microbial pathogens. We investigated the role of PI3K signaling pathways in the regulation of the oxidase during phagocytosis of Staphylococcus aureus and Escherichia coli by mouse and human neutrophils, a mouse macrophage-like cell line and a human myeloid-like cell line. Phagocytosis of these bacteria was promoted by serum, independent of serum-derived antibodies, and effectively abolished in mouse neutrophils lacking the β2-integrin common chain, CD18. A combination of PI3K isoform-selective inhibitors, mouse knock-outs, and RNA-interference indicated CD18-dependent activation of the oxidase was independent of class I and II PI3Ks, but substantially dependent on the single class III isoform (Vps34). Class III PI3K was responsible for the synthesis of PtdIns(3)P on phagosomes containing either bacteria. The use of mouse neutrophils carrying an appropriate knock-in mutation indicated that PtdIns(3)P binding to the PX domain of their p40phox oxidase subunit is important for oxidase activation in response to both S aureus and E coli. This interaction does not, however, account for all the PI3K sensitivity of these responses, particularly the oxidase response to E coli, suggesting that additional mechanisms for PtdIns(3)P-regulation of the oxidase must exist.

Chemical Inhibition of Alpha-Toxin, a Key Corneal Virulence Factor of Staphylococcus aureus

2009 ◽  
Vol 50 (6) ◽  
pp. 2848-2854 ◽  
Author(s):  
C. C. McCormick ◽  
A. R. Caballero ◽  
C. L. Balzli ◽  
A. Tang ◽  
R. J. O'Callaghan
Keyword(s):  
Staphylococcus Aureus ◽  
Virulence Factor ◽  
Alpha Toxin ◽  
Toxin A ◽  
Chemical Inhibition

scholarly journals Sex-dependent dysregulation of human neutrophil responses by bisphenol A

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Wioletta Ratajczak-Wrona ◽  
Marzena Garley ◽  
Malgorzata Rusak ◽  
Karolina Nowak ◽  
Jan Czerniecki ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Bisphenol A ◽  
Total Concentration ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Human Neutrophils ◽  
Boyden Chamber ◽  
No Production ◽  
Pathogen Elimination ◽  
Latex Beads

Abstract Background In the present study, we aimed to investigate selected functions of human neutrophils exposed to bisphenol A (BPA) under in vitro conditions. As BPA is classified among xenoestrogens, we compared its action and effects with those of 17β-estradiol (E2). Methods Chemotaxis of neutrophils was examined using the Boyden chamber. Their phagocytosis and nicotinamide adenine dinucleotide phosphate hydrogen (NADPH) oxidase activity were assessed via Park’s method with latex beads and Park’s test with nitroblue tetrazolium. To assess the total concentration of nitric oxide (NO), the Griess reaction was utilized. Flow cytometry was used to assess the expression of cluster of differentiation (CD) antigens. The formation of neutrophil extracellular traps (NETs) was analyzed using a microscope (IN Cell Analyzer 2200 system). Expression of the investigated proteins was determined using Western blot. Results The analysis of results obtained for both sexes demonstrated that after exposure to BPA, the chemotactic capacity of neutrophils was reduced. In the presence of BPA, the phagocytic activity was found to be elevated in the cells obtained from women and reduced in the cells from men. Following exposure to BPA, the percentage of neutrophils with CD14 and CD284 (TLR4) expression, as well as the percentage of cells forming NETs, was increased in the cells from both sexes. The stimulatory role of BPA and E2 in the activation of NADPH oxidase was observed only in female cells. On the other hand, no influence of E2 on the expression of CD14 and CD284, chemotaxis, phagocytosis, and the amount of NET-positive neutrophils was found for both sexes. The study further showed that BPA intensified NO production and iNOS expression in the cells of both sexes. In addition, intensified expression of all tested PI3K-Akt pathway proteins was observed in male neutrophils. Conclusions The study demonstrated the influence of BPA on neutrophil functions associated with locomotion and pathogen elimination, which in turn may disturb the immune response of these cells in both women and men. Analysis of the obtained data showed that the effect of this xenoestrogen on the human neutrophils was more pronounced than E2.

Effects of red grape juice polyphenols in NADPH oxidase subunit expression in human neutrophils and mononuclear blood cells

2009 ◽  
Vol 102 (8) ◽  
pp. 1125-1135 ◽  
Author(s):  
Alberto Dávalos ◽  
Gema de la Peña ◽  
Carolina C. Sánchez-Martín ◽  
M. Teresa Guerra ◽  
Begoña Bartolomé ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Red Wine ◽  
Grape Juice ◽  
Cell Types ◽  
Human Neutrophils ◽  
Superoxide Anion Production ◽  
Oxidase Subunit ◽  
Subunit Expression ◽  
Red Grape Juice ◽  
Red Grape

The NADPH oxidase enzyme system is the main source of superoxide anions in phagocytic and vascular cells. NADPH oxidase-dependent superoxide generation has been found to be abnormally enhanced in several chronic diseases. Evidence is accumulating that polyphenols may have the potential to improve cardiovascular health, although the mechanism is not fully established. Consumption of concentrated red grape juice, rich in polyphenols, has been recently shown to reduce NADPH oxidase activity in circulating neutrophils from human subjects. In the present work we studied whether red grape juice polyphenols affected NADPH oxidase subunit expression at the transcription level. For this, we used human neutrophils and mononuclear cells from peripheral blood, HL-60-derived neutrophils and the endothelial cell line EA.hy926.Superoxide production was measured with 2′7′-dichlorofluorescein diacetate or lucigenin, mRNA expression by real-time RT-PCR and protein expression by Western blot. Each experiment was performed at least three times. In all cell types tested, red grape juice, dealcoholised red wine and pure polyphenols decreased superoxide anion production. Red grape juice and dealcoholised red wine selectively reduced p47phox, p22phox and gp91phox expression at both mRNA and protein levels, without affecting the expression of p67phox. Pure polyphenols, particularly quercetin, also reduced NADPH oxidase subunit expression, especially p47phox, in all cell types tested. The present results showing that red grape juice polyphenols reduce superoxide anion production provide an alternative mechanism by which consumption of grape derivatives may account for a reduction of oxidative stress associated with cardiovascular and/or inflammatory diseases related to NADPH oxidase superoxide overproduction.

scholarly journals Staphylococcus aureus, phagocyte NADPH oxidase and chronic granulomatous disease

2016 ◽  
pp. fuw042 ◽  
Author(s):  
Helene Buvelot ◽  
Klara M. Posfay-Barbe ◽  
Patrick Linder ◽  
Jacques Schrenzel ◽  
Karl-Heinz Krause
Keyword(s):  
Staphylococcus Aureus ◽  
Nadph Oxidase ◽  
Chronic Granulomatous Disease ◽  
Granulomatous Disease ◽  
Phagocyte Nadph Oxidase
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