What Happens Once the Neutrophils Arrive?
A neutrophil will engulf the bacterium, ingesting it, and then digest it by injecting chemicals that will break it down. Most of those chemicals are enzymes that break down many of the chemicals that make up the bacteria. Neutrophils can kill only a few things – about 20 – before they start to die. Once a neutrophil has started to die, it will send out a signal of its imminent death by making characteristic signalling proteins, which it displays on its surface. These proteins attract another sort of cell known as a macrophage, which will arrive to ‘eat’ the neutrophils and the remnants of the bacterium contained in the neutrophil. Most of the chemicals are recycled. If a large number of neutrophils are dying in one place, the macrophages sometimes can’t recycle them fast enough, which is how abscesses are formed. An abscess is a crust of neutrophils containing a clear fluid, which consists of bacteria and dead neutrophils. It is sealed so bacteria can’t get out and more neutrophils can
