The mechanism underlying neutrophil function  

Neutrophils are the first line of cellular defense of the innate immune system. They kill microorganisms in the phagosome or by releasing microbicidal products into the extracellular space. In resting neutrophils, these microbicidal molecules are segregated in vesicles to protect the host from uncontrolled activation. Exocytosis in neutrophils is a crucial event in inflammation and innate immune response. Neutrophils contain four types of secretory organelles that hold a variety of specialized proteins which are essential for the microbicidal activity of these cells. The hierarchy that characterizes the secretory process of these granules correlates with the different roles of their cargo proteins in the processes of adhesion, migration, chemotaxis, phagocytosis and the production of reactive oxygen species and neutrophil extracellular traps (NETs). Tight regulation of the neutrophil function is essential in order to control both a proper response to infection and inflammation.