When bacteria, viruses, injuries, or other threats are detected, neutrophils can produce neutrophil extracellular traps (NETs) — sticky webs made of long nucleosome strings that trap and immobilize pathogens to stop the threat from spreading around the body. NETs are composed of microbicidal components that include DNA, histones, and granule proteins such as myeloperoxidase (MPO) and neutrophil elastase (NE).

NETs are released from neutrophils in a mechanism of cell death, termed NETosis, that is independent from apoptosis and necrosis. NETosis can be activated by the presence of pathogens or induced by immune components such as antibodies and cytokines. During NETosis, nuclear membranes are destructed, histones are modified, and chromatin is decondensated. The cell plasma membrane then ruptures leading to the release of NETs containing nucleosomes and bactericidal proteins into the extracellular space.  Read more…