The intriguing host innate immune response: novel anti-parasitic defence by neutrophil extracellular traps.
The capacity of polymorphonuclear neutrophils (PMN) and other leucocytes of the innate immune system to expel their DNA in a controlled process into the extracellular environment to trap and kill pathogenic microorganisms led to a paradigm shift in our comprehension of host leucocyte-pathogen interactions. Formation of neutrophil extracellular traps (NETs) has recently been recognized as a novel effector mechanism of the host innate immune response against microbial infections. Meanwhile evidence has arisen that NET formation is a widely spread mechanism in vertebrates and invertebrates and extends not only to the entrapment of microbes, fungi and viruses but also to the capture of protozoan and metazoan parasites. PMN produce NETs after stimulation with mitogens, cytokines or pathogens in a controlled process which depends on reactive oxygen species (ROS) and the induction of the Raf-MEK-ERK-mediated signalling pathway cascade. NETs consist of nuclear DNA as a backbone decorated with histones, antimicrobial peptides, and PMN-specific granular enzymes thereby providing an extracellular matrix capable of entrapping and killing invasive pathogens. This review is intended to summarize parasite-related data on NETs. Special attention will be given to NET-associated mechanisms by which parasites, in particular apicomplexa, might be hampered in their ability to reproduce within the host cell and complete the life cycle.
Institute of Parasitology,Justus Liebig University Giessen,Giessen,Germany.
Carlos
C
Hermosilla
Institute of Parasitology,Justus Liebig University Giessen,Giessen,Germany.
Tamara Muñoz
TM
Caro
ICAAM - Instituto Ciências Agrárias e Ambientais Mediterrânicas,IIFA/Universidade de Évora,Portugal.
Liliana M R
LM
Silva
Department of Animal Pathology, Parasitology Unit,University of Las Palmas de Gran Canaria,Spain.
Antonio
A
Ruiz
Institute of Parasitology,Justus Liebig University Giessen,Giessen,Germany.
Anja
A
Taubert
D000818:Animals; D065206:Extracellular Traps; D054884:Host-Pathogen Interactions; D007113:Immunity, Innate; D009504:Neutrophils / Q000276:immunology*; D010273:Parasitic Diseases, Animal / Q000517:prevention & control*; D017382:Reactive Oxygen Species / Q000378:metabolism
D017382:Reactive Oxygen Species