Journal: Frontiers in Immunology

Article Title: Neutrophil Extracellular Traps Activate Proinflammatory Functions of Human Neutrophils

doi: 10.3389/fimmu.2021.636954

Figure Lengend Snippet: Activation of phagocytosis by NETs. Neutrophils were exposed to PMA, NETs, fNETs or left untreated and phagocytosis of fluorescent-labelled particles was assessed by microscopical examination and flow cytometry. (A) Phagocytosis of latex beads was visualized of Giemsa-stained neutrophils by fluorescence microscopy. Size bar=20 µm. (B–D) Representative histogram of neutrophils after phagocytosis of latex beads (B) , opsonized S. aureus bioparticles (C) or opsonized E. coli bioparticles (D) . Signals on the right side of the dashed line in panels B, C and D were considered as phagocytosing cells. Dotted line=neutrophils without particles; bold line=untreated neutrophils; orange=neutrophils exposed to fNETs; blue=neutrophils exposed to NETs. (E–H) Phagocytosis was assessed by analyzing the percent of neutrophils with ingested fluorescent beads (E) and mean fluorescence intensity (MFI) of cells that phagocytosed beads (F) S. aureus (G) or E. coli (H) by flow cytometry. Statistical analysis by ordinary one-way ANOVA with a post hoc Turkey’s test. Asterisks above the bars indicate significance compared to untreated cells. n=3 **=p ≤ 0,01, ***=p ≤ 0,001. n.s., not significant.

Article Snippet: The preparations contained >99% granulocytes, of which >96% were neutrophils and 1%–4% were eosinophils, as determined by Giemsa staining (Diff Quik ® Fix, Medion Diagnostics, Berlin, Germany) of cytocentrifuged (Shandon) samples ( ).

Techniques: Activation Assay, Flow Cytometry, Staining, Fluorescence, Microscopy