Neutrophil extracellular traps

A scanning electron microscope image of NETs engulfing fungal cells (Candida albicans) in an infected mouse lung. (Click on image for more details.)[1]
Fluorescent image of cultivated neutrophils isolated from venous blood of human with Alzheimer Disease. Sample was treated with Hoechst 33342 dye that is used to stain DNA. The picture shows the release of DNA by a neutrophil as foggy area in the center of the view field indicating the spontaneous activation of neutrophil extracellular traps (NETs) formation in AD patients that is not usually observed in healthy mates. Magnification x40.

Neutrophil extracellular traps (NETs) are networks of extracellular fibers, primarily composed of DNA from neutrophils, which bind pathogens.[2] Neutrophils are the immune system's first line of defense against infection and have conventionally been thought to kill invading pathogens through two strategies: engulfment of microbes and secretion of anti-microbials. In 2004, a novel third function was identified: formation of NETs. NETs allow neutrophils to kill extracellular pathogens while minimizing damage to the host cells.[3] Upon in vitro activation with the pharmacological agent phorbol myristate acetate (PMA), Interleukin 8 (IL-8) or lipopolysaccharide (LPS), neutrophils release granule proteins and chromatin to form an extracellular fibril matrix known as NET through an active process.[2]

  1. ^ Urban, Constantin F.; Ermert, David; Schmid, Monika; Abu-Abed, Ulrike; Goosmann, Christian; Nacken, Wolfgang; Brinkmann, Volker; Jungblut, Peter R.; Zychlinsky, Arturo; Levitz, Stuart M. (30 October 2009). "Neutrophil Extracellular Traps Contain Calprotectin, a Cytosolic Protein Complex Involved in Host Defense against Candida albicans". PLOS Pathogens. 5 (10): e1000639. doi:10.1371/journal.ppat.1000639. PMC 2763347. PMID 19876394.
  2. ^ a b Brinkmann, Volker; Ulrike Reichard; Christian Goosmann; Beatrix Fauler; Yvonne Uhlemann; David S. Weiss; Yvette Weinrauch; Arturo Zychlinsky (2004-03-05). "Neutrophil Extracellular Traps Kill Bacteria". Science. 303 (5663): 1532–1535. Bibcode:2004Sci...303.1532B. doi:10.1126/science.1092385. PMID 15001782. S2CID 21628300.
  3. ^ Nirmala GJ and Lopus M (2020) Cell death mechanisms in eukaryotes. Cell Biol Toxicol, 36, 145–164. doi: /10.1007/s10565-019-09496-2. PMID 31820165