T lymphocyte priming by neutrophil extracellular traps links innate and adaptive immune responses

K Tillack, P Breiden, R Martin… - The Journal of …, 2012 - journals.aai.org
K Tillack, P Breiden, R Martin, M Sospedra
The Journal of Immunology, 2012journals.aai.org
Polymorphonuclear neutrophils constitute the first line of defense against infections. Among
their strategies to eliminate pathogens they release neutrophil extracellular traps (NETs),
being chromatin fibers decorated with antimicrobial proteins. NETs trap and kill pathogens
very efficiently, thereby minimizing tissue damage. Furthermore, NETs modulate
inflammatory responses by activating plasmacytoid dendritic cells. In this study, we show
that NETs released by human neutrophils can directly prime T cells by reducing their …
Abstract
Polymorphonuclear neutrophils constitute the first line of defense against infections. Among their strategies to eliminate pathogens they release neutrophil extracellular traps (NETs), being chromatin fibers decorated with antimicrobial proteins. NETs trap and kill pathogens very efficiently, thereby minimizing tissue damage. Furthermore, NETs modulate inflammatory responses by activating plasmacytoid dendritic cells. In this study, we show that NETs released by human neutrophils can directly prime T cells by reducing their activation threshold. NETs-mediated priming increases T cell responses to specific Ags and even to suboptimal stimuli, which would not induce a response in resting T cells. T cell priming mediated by NETs requires NETs/cell contact and TCR signaling, but unexpectedly we could not demonstrate a role of TLR9 in this mechanism. NETs-mediated T cell activation adds to the list of neutrophil functions and demonstrates a novel link between innate and adaptive immune responses.
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