Distinct Compartmentalization of the Chemokines CXCL1 and CXCL2 and the Atypical Receptor ACKR1 Determine Discrete Stages of Neutrophil Diapedesis

Immunity. 2018 Dec 18;49(6):1062-1076.e6. doi: 10.1016/j.immuni.2018.09.018. Epub 2018 Nov 13.

Abstract

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.

Keywords: ACKR1; CXCR2; chemokines; endothelium; extravasation; inflammation; neutrophils; pericytes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abdominal Muscles / drug effects
  • Abdominal Muscles / immunology
  • Abdominal Muscles / metabolism
  • Animals
  • Chemokine CXCL1 / genetics
  • Chemokine CXCL1 / immunology*
  • Chemokine CXCL1 / metabolism
  • Chemokine CXCL2 / genetics
  • Chemokine CXCL2 / immunology*
  • Chemokine CXCL2 / metabolism
  • Duffy Blood-Group System / genetics
  • Duffy Blood-Group System / immunology*
  • Duffy Blood-Group System / metabolism
  • Endothelial Cells / drug effects
  • Endothelial Cells / immunology
  • Endothelial Cells / metabolism
  • Gene Expression Profiling
  • Gene Expression Regulation
  • Intercellular Junctions / drug effects
  • Intercellular Junctions / immunology
  • Intercellular Junctions / metabolism
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Mice, Transgenic
  • Neutrophils / cytology
  • Neutrophils / immunology*
  • Neutrophils / metabolism
  • Receptors, Cell Surface / genetics
  • Receptors, Cell Surface / immunology*
  • Receptors, Cell Surface / metabolism
  • Transendothelial and Transepithelial Migration / drug effects
  • Transendothelial and Transepithelial Migration / genetics
  • Transendothelial and Transepithelial Migration / immunology*
  • Tumor Necrosis Factor-alpha / pharmacology

Substances

  • Chemokine CXCL1
  • Chemokine CXCL2
  • Dfy protein, mouse
  • Duffy Blood-Group System
  • Receptors, Cell Surface
  • Tumor Necrosis Factor-alpha