eoe sub articles

EoE Sub Articles

1. Polarization of HMDM
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	<li>Under sterile conditions, prepare the M1 priming media by adding interferon &#947; (IFN&#947;; 20 ng/mL) and lipopolysaccharide (LPS; 1 &#956;g/mL) to the complete RPMI-1640 culture media. Prepare the M2 priming media by adding interleukin 4 (IL-4; 20 ng/mL) to the complete RPMI-1640 culture media.</li>
	<li>Under sterile conditions, aspirate media from the tissue culture plate wells that contain the Human monocyte-derived macrophages, HMDM, which have been seeded and ...

in vitro stimulation and visualization of macrophage extracellular traps

Source: Zhang, Y., et al. <a href="https://app.jove.com/v/60541">In Vitro Stimulation and Visualization of Extracellular Trap Release in Differentiated Human Monocyte-derived Macrophages.</a> J. Vis. Exp. (2019).
This video demonstrates in vitro stimulation of macrophage extracellular traps (METs) in human monocyte-derive macrophages using different inflammatory stimuli such as TNF-alpha, PMA, and HOCL. The video also demonstrates the method of SYTOX dye staining of METs for visualization.

In Vitro Stimulation and Visualization of Macrophage Extracellular Traps

1. Polarization of HMDM

	Under sterile conditions, prepare the M1 priming media by adding interferon &#947; (IFN&#947;; 20 ng/mL) and lipopolysaccharide ...

Begin with an adherent macrophage culture.
Add pro-inflammatory cytokines.
The cytokine binds to the macrophage surface receptors, initiating a series of inflammatory events.
First, the cytokine signaling triggers the production of antimicrobial peptides.
Simultaneously, the chromatin within the macrophage nucleus undergoes decondensation.
This process, coupled with changes in membrane composition, disrupts the nuclear membrane, releasing decondensed chromatin into the cytoplasm.
In the cytoplasm, the antimicrobial peptide interacts with the released chromatin.
Cytokine signaling-mediated cell membrane permeabilization causes the decondensed chromatin to be released into the extracellular space, forming a Macrophage Extracellular Trap, or MET.
These web-like structures consist of DNA, histones, antimicrobial molecules, and enzymes.
Add SYTOX green, a fluorescent nucleic acid dye that selectively binds to the exposed DNA in the extracellular traps.
Under a fluorescence microscope, the MET appears as green streaks of extracellular DNA released from the stimulated macrophage.

in-vitro-stimulation-visualization-macrophage-extracellular

Research

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Immunology

Immunodiagnostics

Imaging and Visualization Techniques

Simplified Human Neutrophil Extracellular Traps (NETs) Isolation and Handling

Neutrophil Extracellular Traps (NETs) have been recently identified as part of the neutrophil&#8217;s antimicrobial armamentarium. Apart from their role in fighting infections, recent research has demonstrated that they may be involved in many other disease processes, including cancer progression. Isolating purified NETs is a crucial element to allow the study of these functions.
In this video, we demonstrate a simplified method of cell free NET isolation from human whole blood using readily available reagents. Isolated NETs can then be used for immunofluorescence staining, blotting or various functional assays. This enables an assessment of their biologic properties in the absence of the potential confounding effects of neutrophils themselves.
A density gradient separation technique is employed to isolate neutrophils from healthy donor whole blood. Isolated neutrophils are then stimulated by phorbol 12-myristate 13-acetate (PMA) to induce NETosis. Activated neutrophils are then discarded, and a cell-free NET stock is obtained.
We then demonstrate how isolated NETs can be used in an adhesion assay with A549 human lung cancer cells. The NET stock is used to coat the wells of a 96 well cell culture plate O/N, and after ensuring an adequate NET monolayer formation on the bottom of the wells, CFSE labeled A549 cells are added. Adherent cells are quantified using a Nikon TE300 fluorescent microscope. In some wells, 1000U DNAse1 is added 10 min before counting to degrade NETs

Simplified Human Neutrophil Extracellular Traps NETs Isolation and Handling

In the following protocol, we describe a very simple way to isolate Neutrophil Extracellular traps (NETs) from human whole blood using readily available reagents. We then demonstrate how the isolated NETs can be used in an in vitro adhesion assay with cancer cells.

Neutrophil Extracellular Traps (NETs) have been recently identified as part of the neutrophil&#8217;s antimicrobial armamentarium. Apart from their role ...

JoVE Journal

Immunology and Infection

Visualizing Macrophage Extracellular Traps Using Confocal Microscopy

A primary method used to define the presence of neutrophil extracellular traps (NETs) is confocal microscopy. We have modified established confocal microscopy methods to visualize macrophage extracellular traps (METs). These extracellular traps are defined by the presence of extracellular chromatin with co-expression of other components such as granule proteases, citrullinated histones, and peptidyl arginase deiminase (PAD). The expression of METs is generally measured after exposure to a stimulus and compared to un-stimulated samples. Samples are also included for background and isotype control. Cells are analyzed using well-defined image analysis software. Confocal microscopy may be used to define the presence of METs both in vitro and in vivo in lung tissue.

Macrophage extracellular traps are a newly described entity. This article will concentrate on confocal microscopy methods and how they are visualized in vitro and in vivo from lung samples.

A primary method used to define the presence of neutrophil extracellular traps (NETs) is confocal microscopy. We have modified established confocal ...

Morphological and Compositional Analysis of Neutrophil Extracellular Traps Induced by Microbial and Chemical Stimuli

Neutrophils function as the first line of cellular defense in an innate immune response by employing diverse mechanisms, such as the formation of neutrophil extracellular traps (NETs). This study analyzes the morphological and compositional changes in NETs induced by microbial and chemical stimuli using standardized in vitro methodologies for NET induction and characterization with human cells. The procedures described here allow the analysis of NET morphology (lytic or non-lytic) and composition (DNA-protein structures and enzymatic activity), and the effect of soluble factors or cellular contact on such characteristics. Additionally, the techniques described here could be modified to evaluate the effect of exogenous soluble factors or cellular contact on NET composition.
The applied techniques include the purification of polymorphonuclear cells from human peripheral blood using a double density gradient (1.079-1.098 g/mL), guaranteeing optimal purity and viability (&#8805; 95%) as demonstrated by Wright's staining, trypan blue exclusion, and flow cytometry, including FSC versus SSC analysis and 7AAD staining. NET formation is induced with microbial (Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans) and chemical (phorbol myristate acetate, HOCl) stimuli, and the NETs are characterized by DNA-DAPI staining, immunostaining for the antimicrobial peptide cathelicidin (LL37), and quantification of enzymatic activity (neutrophil elastase, cathepsin G, and myeloperoxidase). The images are acquired through fluorescence microscopy and analyzed with ImageJ.

Presented here is a protocol for the induction and analysis of in vitro neutrophil extracellular traps (NETs). Quantification of DNA, cathelicidin (LL37), and enzyme activity yielded data that show the variability in the composition and morphology of NETs induced by microbial and chemical stimuli under similar controlled conditions.

In Vitro Stimulation and Visualization of Macrophage Extracellular Traps

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