[PDF][PDF] Distinct compartmentalization of the chemokines CXCL1 and CXCL2 and the atypical receptor ACKR1 determine discrete stages of neutrophil diapedesis

T Girbl, T Lenn, L Perez, L Rolas, A Barkaway, A Thiriot… - Immunity, 2018 - cell.com
T Girbl, T Lenn, L Perez, L Rolas, A Barkaway, A Thiriot, C Del Fresno, E Lynam, E Hub…
Immunity, 2018cell.com
Neutrophils require directional cues to navigate through the complex structure of venular
walls and into inflamed tissues. Here we applied confocal intravital microscopy to analyze
neutrophil emigration in cytokine-stimulated mouse cremaster muscles. We identified
differential and non-redundant roles for the chemokines CXCL1 and CXCL2, governed by
their distinct cellular sources. CXCL1 was produced mainly by TNF-stimulated endothelial
cells (ECs) and pericytes and supported luminal and sub-EC neutrophil crawling …
Summary
Neutrophils require directional cues to navigate through the complex structure of venular walls and into inflamed tissues. Here we applied confocal intravital microscopy to analyze neutrophil emigration in cytokine-stimulated mouse cremaster muscles. We identified differential and non-redundant roles for the chemokines CXCL1 and CXCL2, governed by their distinct cellular sources. CXCL1 was produced mainly by TNF-stimulated endothelial cells (ECs) and pericytes and supported luminal and sub-EC neutrophil crawling. Conversely, neutrophils were the main producers of CXCL2, and this chemokine was critical for correct breaching of endothelial junctions. This pro-migratory activity of CXCL2 depended on the atypical chemokine receptor 1 (ACKR1), which is enriched within endothelial junctions. Transmigrating neutrophils promoted a self-guided migration response through EC junctions, creating a junctional chemokine "depot" in the form of ACKR1-presented CXCL2 that enabled efficient unidirectional luminal-to-abluminal migration. Thus, CXCL1 and CXCL2 act in a sequential manner to guide neutrophils through venular walls as governed by their distinct cellular sources.
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