NETs: a new strategy for using old weapons

Abstract

As key players in the host innate immune response, neutrophils are recruited to sites of infection and constitute the first line of defense. They employ three strategies to eliminate invading microbes: microbial uptake, the secretion of antimicrobials, and the recently described release of Neutrophil Extracellular Traps (NETs). Composed of decondensed chromatin and antimicrobial proteins, NETs bind and kill a variety of microbes including bacteria, fungi, and parasites. In addition to using a repertoire of known antimicrobials, NETs incorporate histones into the antimicrobial arsenal. Furthermore, NETs may contribute to microbial containment by forming a physical barrier and a scaffold, to enhance antimicrobial synergy while minimizing damage to host tissues. Their role in innate immunity is only now being uncovered. © 2009 Elsevier Ltd. All rights reserved.