The role of neutrophils in the immune system: an overview

Abstract

Neutrophils, also known as polymorphonuclear leukocytes (PMNs), have long been considered as the short-lived, nonspecific white cells that form pus-and also happen to kill invading microbes. Indeed, neutrophils were often neglected (and largely not considered) as immune cells. This historic view of neutrophils has changed considerably over the past several decades, and we know now that, in addition to playing the predominant role in the clearance of bacteria and fungi, they play a major role in shaping the host response to infection and immune system homeostasis. The change in our view of the role of neutrophils in the immune system has been due in large part to the study of these cells in vitro. Such work has been made possible by new and/or improved methods and approaches used to investigate neutrophils. These methods are the focus of this volume.

Fig. 1

Illustration of key neutrophil functions. Note that, for production reactive oxygen species, secretion of granule components, and production of cytokines and chemokines, only a few representative molecules are shown. HNE human neutrophil elastase, IL-8 interleukin-8, IL-4 interleukin-4, LF lactoferrin, MPO myeloperoxidase, TNF-α tumor nectosis factor-α