scholarly journals Natural Variation in Clinical Isolates of Candida albicans Modulates Neutrophil Responses

mSphere ◽  
2020 ◽  
Vol 5 (4) ◽  
Author(s):  
Madhu Shankar ◽  
Tricia L. Lo ◽  
Ana Traven
Keyword(s):  
Reactive Oxygen Species ◽  
Candida Albicans ◽  
Reactive Oxygen ◽  
Neutrophil Extracellular Traps ◽  
Prototype Strain ◽  
Human Neutrophils ◽  
Oxygen Species ◽  
Content Type ◽  
Extracellular Traps ◽  
Strain Sc5314

ABSTRACT Neutropenia predisposes patients to life-threatening infection with Candida albicans, a commensal and opportunistic fungal pathogen. How phenotypic variation in C. albicans isolates dictates neutrophil responses is poorly understood. By using a panel of clinical C. albicans strains, here we report that the prototype strain SC5314 induces the most potent accumulation of reactive oxygen species (ROS) and neutrophil extracellular traps (NETs) by human neutrophils of all tested isolates. ROS and NET accumulation positively correlated with the degree of hyphal formation by the isolates, the hypha being the fungal morphotype that promotes pathogenesis. However, there was no correlation of ROS and NET accumulation with fungal killing by neutrophils. Fungal killing was also not correlated with phagocytosis levels or oxidative stress susceptibility of the isolates. The bloodstream isolate P94015 cannot make hyphae and was previously shown to be hyperfit in the murine gut commensalism model. Our results show that P94015 displays poor phagocytosis by neutrophils, the least ROS and NET accumulation of all tested isolates, and resistance to neutrophil-mediated killing. Our data suggest that reduced susceptibility to neutrophils is likely to be independent from a previously described genetic mutation in P94015 that promotes commensalism. Reduced clearance by neutrophils could benefit commensal fitness of C. albicans and could also have promoted the virulence of P94015 in the human patient in the absence of hyphal morphogenesis. Collectively, our study provides new insights into neutrophil interactions with C. albicans and suggests that studying diverse isolates informs knowledge of the relevant aspects of this key immune interaction. IMPORTANCE Neutrophils are the key immune cell type for host defenses against infections with Candida albicans. C. albicans strains isolated from patients display large phenotypic diversity, but how this diversity impacts host-pathogen interactions with neutrophils is incompletely defined. Here, we show that important neutrophil responses, such as accumulation of reactive oxygen species and neutrophil extracellular traps, as well as the levels of phagocytosis and killing of the pathogen, differ when comparing diverse C. albicans isolates. A bloodstream patient isolate previously described as more suited to commensalism than pathogenesis in animal models is relatively “silent” to neutrophils and resistant to killing. Our findings illuminate the relationships between fungal morphogenesis, neutrophil responses, and C. albicans survival. Our findings suggest that host phenotypes of a commensally adapted strain could be driven by resistance to immune clearance and indicate that we should extend our studies beyond the “prototype” strain SC5314 for deeper understanding of Candida-neutrophil interactions.

Cisplatin Fails To Stimulate Production Of Reactive Oxygen Species and Release Of Neutrophil Extracellular Traps By Human Neutrophils In Vitro

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4714-4714
Author(s):  
Leonardo Pasalic ◽  
Campbell Heather ◽  
Shane Thomas ◽  
Vivien M Chen
Keyword(s):  
Reactive Oxygen Species ◽  
Fluorescent Microscopy ◽  
Neutrophil Extracellular Traps ◽  
Vehicle Control ◽  
Human Neutrophils ◽  
Oxygen Species ◽  
Extracellular Traps ◽  
Spontaneous Production ◽  
Confocal Fluorescent Microscopy

Background Cisplatin is a commonly used antineoplastic agent for treatment of a broad range of cancers. Cisplatin-based treatment has been associated with a significant risk of venous thromboembolism. The mechanisms through which cisplatin contributes to a prothrombotic state remain unclear. Neutrophil extracellular traps (NETs) consist of web-like DNA–histone core decorated with granule proteins and are released from activated neutrophils in a process dependent on reactive oxygen species (ROS), in particular hypochlorous acid (HOCl). Recently, NETs have been shown to play an important role in initiation and propagation of venous thrombus in a number of animal models of deep vein thrombosis. The aim of this study was to investigate whether NETs may provide a potential link between cisplatin and venous thromboembolism. Methods and Results To assess the effect of cisplatin on release of NETs by ex vivo human neutrophils isolated by positive immunomagnetic selection we visualised NETs release by confocal fluorescent microscopy and performed fluorimetric quantification of cell-free DNA (CFDNA) using either SYTOX Green nucleic acid stain (10 µM) or an ultrasensitive fluorescent assay Picogreen Quant IT (Invitrogen). In contrast to stimulation with phorbol 12-myristate 13-acetate (PMA) (25 nM),which resulted in 22 ng/104neutrophils of detectable CFDNA, neither of these two assays could detect any significant release of CFDNA by human neutrophils exposed to cisplatin (15 µM) for 2 or 4 hours above baseline similar with vehicle control. Furthermore, confocal fluorescent microscopy imaging of neutrophils stained with non-cell permeable DNA dye SYTOX Red (Invitrogen) demonstrated no difference in NET formation between control and cisplatin treated human neutrophils. Thus we could not demonstrate that NETS are produced in response to cisplatin treatment. In view of consistent reports that NET formation is ROS dependent we decided to investigate whether cisplatin exposure leads to production of ROS by human neutrophils. Few published studies into the effects of cisplatin on the production of ROS by human neutrophils in vitro offer conflicting results. We used flow cytometry and fluorescent probe hydroethidine (HE) for detection of intercellular superoxide anion radical in HL60 granulocytic cells in the presence of cisplatin (up to 50 µM). Differentiation down the granulocytic lineage after stimulation with ATRA was confirmed by light microscopy and by flow cytometry. Capacity of differentiated HL60 cells to generate NET formation after PMA stimulation was confirmed by fluorescence microscopy. Cisplatin failed to augment the spontaneous production of ROS by ATRA differentiated HL60 cells. The number of viable ethidium-high cells in cisplatin treated group did not differ from the vehicle control indicating no detectable production of ROS in response to cisplatin. In contrast, positive control treatment with PMA (25 nM) and menadione (40 µM) resulted in 4- and 20-fold increase in viable ethidium-high population respectively. ROS generation by human neutrophils was measured by a colorimetric assay for chlorination of extracellular taurine to determine if exposure to cisplatin results in the production of HOCl by human neutrophils in vitro. Treatment of resting neutrophils with cisplatin (15 µM) for 30 min or 120 min was not associated with an increase in the spontaneous production of HOCl above the baseline. Furthermore, the PMA (25 nM)-activated generation of HOCl production was not increased by pre-treating neutrophils with cisplatin indicating that there was no potentiation of ROS by pre-treatment with cisplatin. Discussion and Conclusion Our results suggest that cisplatin fails to induce release of NETs or HOCl from human neutrophils in vitro. These negative findings seem to be at odds with the well described pro-oxidative actions of cisplatin. One possible explanation centres on reported findings that the pro-oxidative effects of cisplatin are dependent on the mitochondrial generation of ROS whilst the mitochondria-generated ROS appear not to be instrumental to NET formation. Therefore, we postulate that cisplatin may not be able to induce NET formation by human neutrophils, which are known to contain few mitochondria, due to a sub-threshold ROS signal. Therefore it appears that cisplatin-associated increased risk of venous thrombosis is unlikely to be mediated through NETs. Disclosures: No relevant conflicts of interest to declare.

scholarly journals β-Glucan Induces Reactive Oxygen Species Production in Human Neutrophils to Improve the Killing of Candida albicans and Candida glabrata Isolates from Vulvovaginal Candidiasis

PLoS ONE ◽  
2014 ◽  
Vol 9 (9) ◽  
pp. e107805 ◽  
Author(s):  
Patricia de Souza Bonfim-Mendonça ◽  
Bianca Altrão Ratti ◽  
Janine da Silva Ribeiro Godoy ◽  
Melyssa Negri ◽  
Nayara Cristina Alves de Lima ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Candida Albicans ◽  
Candida Glabrata ◽  
Reactive Oxygen Species Production ◽  
Reactive Oxygen ◽  
Vulvovaginal Candidiasis ◽  
Human Neutrophils ◽  
Oxygen Species ◽  
Species Production

scholarly journals Effects of Gambogic Acid on the Production of Reactive Oxygen Species and Neutrophil Extracellular Traps

2019 ◽  
Vol 33 (S1) ◽  
Author(s):  
Julia Grace Reinke ◽  
Cole Gardner ◽  
Alexandria Jackson ◽  
Shaili Kumar ◽  
Melissa Petreaca
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Neutrophil Extracellular Traps ◽  
Gambogic Acid ◽  
Oxygen Species ◽  
Extracellular Traps

scholarly journals Candida albicans Induces Arginine Biosynthetic Genes in Response to Host-Derived Reactive Oxygen Species

2012 ◽  
Vol 12 (1) ◽  
pp. 91-100 ◽  
Author(s):  
Claudia Jiménez-López ◽  
John R. Collette ◽  
Kimberly M. Brothers ◽  
Kelly M. Shepardson ◽  
Robert A. Cramer ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Candida Albicans ◽  
Amino Acid ◽  
Reactive Oxygen ◽  
Single Amino Acid ◽  
Dependent Manner ◽  
Oxygen Species ◽  
Biosynthetic Genes ◽  
Content Type

ABSTRACTThe interaction ofCandida albicanswith phagocytes of the host's innate immune system is highly dynamic, and its outcome directly impacts the progression of infection. While the switch to hyphal growth within the macrophage is the most obvious physiological response, much of the genetic response reflects nutrient starvation: translational repression and induction of alternative carbon metabolism. Changes in amino acid metabolism are not seen, with the striking exception of arginine biosynthesis, which is upregulated in its entirety during coculture with macrophages. Using single-cell reporters, we showed here that arginine biosynthetic genes are induced specifically in phagocytosed cells. This induction is lower in magnitude than during arginine starvationin vitroand is driven not by an arginine deficiency within the phagocyte but instead by exposure to reactive oxygen species (ROS). Curiously, these genes are induced in a narrow window of sublethal ROS concentrations.C. albicanscells phagocytosed by primary macrophages deficient in thegp91phoxsubunit of the phagocyte oxidase do not express theARGpathway, indicating that the induction is dependent on the phagocyte oxidative burst.C. albicans argpathway mutants are retarded in germ tube and hypha formation within macrophages but are not notably more sensitive to ROS. We also find that theARGpathway is regulated not by the general amino acid control response but by transcriptional regulators similar to theSaccharomyces cerevisiaeArgR complex. In summary, phagocytosis induces this single amino acid biosynthetic pathway in an ROS-dependent manner.

scholarly journals Microfluidic device for simultaneous analysis of neutrophil extracellular traps and production of reactive oxygen species

2016 ◽  
Vol 8 (2) ◽  
pp. 243-252 ◽  
Author(s):  
S. F. Moussavi-Harami ◽  
K. M. Mladinich ◽  
E. K. Sackmann ◽  
M. A. Shelef ◽  
T. W. Starnes ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Microfluidic Device ◽  
Reactive Oxygen ◽  
Neutrophil Extracellular Traps ◽  
Simultaneous Analysis ◽  
Oxygen Species ◽  
Extracellular Traps

Simultaneous analysis of the production of reactive oxygen species and formation of extracellular traps from neutrophils isolated from a drop of blood using a novel microfluidics based approach.

scholarly journals Trypanosoma brucei Lipophosphoglycan Induces the Formation of Neutrophil Extracellular Traps and Reactive Oxygen Species Burst via Toll-Like Receptor 2, Toll-Like Receptor 4, and c-Jun N-Terminal Kinase Activation

2021 ◽  
Vol 12 ◽  
Author(s):  
Kai Zhang ◽  
Ning Jiang ◽  
Xiaoyu Sang ◽  
Ying Feng ◽  
Ran Chen ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Trypanosoma Brucei ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Reactive Oxygen ◽  
Neutrophil Extracellular Traps ◽  
Oxygen Species ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Extracellular Traps ◽  
Toll Like Receptor 2

Trypanosoma brucei brucei is the causative agent of African animal trypanosomosis, which mainly parasitizes the blood of the host. Lipophosphoglycan (LPG), a polymer anchored to the surface of the parasites, activates the host immune response. In this study, we revealed that T. brucei LPG stimulated neutrophils to form neutrophil extracellular traps (NETs) and release the reactive oxygen species (ROS). We further analyzed the involvement of toll-like receptor 2 (TLR2) and toll-like receptor 4 (TLR4) and explored the activation of signaling pathway enzymes in response to LPG stimulation. During the stimulation of neutrophils by LPG, the blockade using anti-TLR2 and anti-TLR4 antibodies reduced the phosphorylation of c-Jun N-terminal kinase (JNK), the release of DNA from the NETs, and the burst of ROS. Moreover, the addition of JNK inhibitor and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor exhibited similar effects. Our data suggest that T. brucei LPG activates the phosphorylation of JNK through TLR2 and TLR4 recognition, which causes the formation of NETs and the burst of ROS.

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