Polymorphonuclear neutrophils, besides their involvement in primary defense against
infections - mainly through phagocytosis, generation of toxic molecules, release of
enzymes, and formation of extracellular traps - are also becoming increasingly important for their contribution to the fine regulation in development of inflammatory and immune responses. These latter functions of neutrophils occur, in part, via their de novo production and release of a large variety of
cytokines, including
chemotactic cytokines (
chemokines). Accordingly, the improvement in technologies for molecular and functional cell analysis, along with concomitant advances in cell purification techniques, have allowed the identification of a continuously growing list of neutrophil-derived
cytokines, as well as the characterization of their biological implications in vitro and/or in vivo. This short review summarizes crucial concepts regarding the modalities of expression, release, and regulation of neutrophil-derived
cytokines. It also highlights examples illustrating the potential implications of neutrophil-derived
cytokines according to recent observations made in humans and/or in experimental animal models.