Abstract: Neutrophils make up approximately 50%～70% of all mammalian leukocytes and are considered a part of the body’s first line of defense against pathogen invasion. Neutrophils play an important role in the innate immune response of the animal body, suppressing or eliminating a variety of invading pathogens through phagocytosis, degranulation and the formation of extracellular traps. Neutrophil extracellular traps (NETs) are fibrous network consist of DNA, granulins and histones that are secreted extracellularly by neutrophils after stimulated by activators, including pathogens. Initially, researchers found that NETs played an important role in fighting bacterial infections by confining bacteria to the site of infection and inhibiting or killing them. As research gradually progressed and developed, it is found that NETs not only played an antibacterial role in bacterial infections, but also had an important role in defending against fungal, parasitic and viral infections. However, pathogens have evolved various evasion strategies to inhibit the resistance of NETs. Some pathogens even utilize NETs to promote infection, making it difficult for patients to recover. This review focuses on the formation of NETs, inducing factors and roles of NETs during pathogenic infections, with a view to providing new ideas for the study of pathogenic infection mechanisms and new ways to prevent and control infections by various pathogens.

Key words: neutrophils, extracellular traps, pathogenic infection