Local microvascular leakage promotes trafficking of activated neutrophils to remote organs
Charlotte Owen-Woods, … , Mathieu-Benoit Voisin, Sussan Nourshargh
Charlotte Owen-Woods, … , Mathieu-Benoit Voisin, Sussan Nourshargh
Published January 23, 2020
Citation Information: J Clin Invest. 2020;130(5):2301-2318. https://doi.org/10.1172/JCI133661.
View: Text | PDF
Research Article Inflammation Vascular biology

Local microvascular leakage promotes trafficking of activated neutrophils to remote organs

Abstract

Increased microvascular permeability to plasma proteins and neutrophil emigration are hallmarks of innate immunity and key features of numerous inflammatory disorders. Although neutrophils can promote microvascular leakage, the impact of vascular permeability on neutrophil trafficking is unknown. Here, through the application of confocal intravital microscopy, we report that vascular permeability–enhancing stimuli caused a significant frequency of neutrophil reverse transendothelial cell migration (rTEM). Furthermore, mice with a selective defect in microvascular permeability enhancement (VEC-Y685F-ki) showed reduced incidence of neutrophil rTEM. Mechanistically, elevated vascular leakage promoted movement of interstitial chemokines into the bloodstream, a response that supported abluminal-to-luminal neutrophil TEM. Through development of an in vivo cell labeling method we provide direct evidence for the systemic dissemination of rTEM neutrophils, and showed them to exhibit an activated phenotype and be capable of trafficking to the lungs where their presence was aligned with regions of vascular injury. Collectively, we demonstrate that increased microvascular leakage reverses the localization of directional cues across venular walls, thus causing neutrophils engaged in diapedesis to reenter the systemic circulation. This cascade of events offers a mechanism to explain how local tissue inflammation and vascular permeability can induce downstream pathological effects in remote organs, most notably in the lungs.

Authors

Charlotte Owen-Woods, Régis Joulia, Anna Barkaway, Loïc Rolas, Bin Ma, Astrid Fee Nottebaum, Kenton P. Arkill, Monja Stein, Tamara Girbl, Matthew Golding, David O. Bates, Dietmar Vestweber, Mathieu-Benoit Voisin, Sussan Nourshargh

×

Figure 5

Vascular leakage induction promotes trafficking of tissue chemokine through venular walls.

Options: View larger image (or click on image) Download as PowerPoint
Vascular leakage induction promotes trafficking of tissue chemokine thro...
Cremaster muscles were injected locally with IL-1β (50 ng) and human CXCL8 (hCXCL8, 500 ng) for 1 hour, followed by i.s. injection of vehicle (control) or histamine for an additional 1 hour. (A) Representative confocal images of postcapillary venules stained for hCXCL8 within an EC (labeled by anti-CD31) isosurface mask with an enlarged image of the boxed region. Scale bars: 2 μm. (B) Quantification of hCXCL8 MFI on EC body and junctions (n = 8 mice/group). (C–F) Plasma levels of locally applied hCXCL8 in WT mice (C), VEC-WT and VEC-Y685F mice (D), in mice treated with a control or anti–VE-PTP Ab (200 μg, i.v.) (E), or treated with an anti–VE-cadherin mAb (i.s. BV13, 100 μg), or a control mAb (nonblocking anti–CD31 mAb, 100 μg) for 3 hours before local administration with hCXCL8 for 1 hour (n = 4–8 mice/group) (F). Data are represented as mean ± SEM (each symbol represents 1 mouse/independent experiment). Statistically significant differences between cell body vehicle versus cell body histamine and EC junction (Jn) vehicle versus Jn histamine groups were analyzed by 1-way ANOVA followed by Bonferroni’s post hoc test (*P < 0.05; **P < 0.01). Differences between the other indicated groups are shown by *P < 0.05; **P < 0.01; ***P < 0.001 analyzed by 2-way ANOVA followed by Bonferroni’s post hoc test (B and D) or 2-tailed paired (B) or unpaired Student’s t test (C, E, and F). NS, not significant.