Neutrophils are a type of white blood cell that make up the front line of the body’s defences against infection. Here, we can see a central living neutrophil amongst a cluster of neutrophils that have expelled their DNA – a dramatic death by “NETosis”.
In chronic inflammation, neutrophils initiate NETosis by relaxing their supercoiled DNA into a mass that fills the cell and becomes coated with intracellular enzymes. The cells then erupt, just like a star going supernova.
Neutrophils have a short life-span, but the enzyme-studded mass of expelled DNA can continue to kill bacteria long after neutrophils die. These large net-like structures can help to limit the spread of pathogens.
In this image, the membranes of these cells are stained in red and DNA is stained in blue, showing the characteristic lobulated nuclear structure of the intact cell. In green is signal from our NAP SmartProbe (Neutrophil Activation Probe), showing a key neutrophilic enzyme called “human neutrophil elastase”.