Neutrophil breaching of the blood vessel pericyte layer during diapedesis requires mast cell-derived IL-17A
Nov 17, 2022·,,,,,,,,,,,·
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Regis Joulia
Idaira María Guerrero-Fonseca
Tamara Girbl
Jonny Coates
Monja Stein
Laura Vázquez-Martínez
Eleanor Lynam
James Whiteford
Michael Schnoor
David Voehringer
Axel Roers
Sussan Nourshargh
Mathieu-Benoit Voisin
Abstract
Neutrophil diapedesis is an immediate step following infections and injury and is driven by complex interactions between leukocytes and various components of the blood vessel wall. Here, we show that perivascular mast cells (MC) are key regulators of neutrophil behaviour within the sub-endothelial space of inflamed venules. Using confocal intravital microscopy, we observe directed abluminal neutrophil motility along pericyte processes towards perivascular MCs, a response that created neutrophil extravasation hotspots. Conversely, MC-deficiency and pharmacological or genetic blockade of IL-17A leads to impaired neutrophil sub-endothelial migration and breaching of the pericyte layer. Mechanistically, identifying MCs as a significant cellular source of IL-17A, we establish that MC-derived IL-17A regulates the enrichment of key effector molecules ICAM-1 and CXCL1 in nearby pericytes. Collectively, we identify a novel MC-IL-17A-pericyte axis as modulator of the final steps of neutrophil diapedesis, with potential translational implications for inflammatory disorders driven by increased neutrophil diapedesis.
Type
Publication
Nature Communications