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Granulocyte Biology & its Disorders
Src family kinase-mediated vesicle trafficking is critical for neutrophil basement membrane penetration
Ferrata Storti Foundation
Haematologica 2020 Volume 105(7):1845-1856
Ina Rohwedder,1 Angela R.M. Kurz,1 Monika Pruenster,1 Roland Immler,1 Robert Pick,1 Tanja Eggersmann,1 Sarah Klapproth,1 Jennifer L. Johnson,2 Sergi Masgrau Alsina,1 Clifford A. Lowell,3 Attila Mócsai,4 Sergio D. Catz2 and Markus Sperandio1
1Walter-Brendel-Center of Experimental Medicine, Institute of Cardiovascular Physiology and Pathophysiology, Klinikum der Universität, Ludwig-Maximilians-University Munich, Planegg-Martinsried, Germany; 2Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA; 3Department of Laboratory Medicine, University of California, San Francisco, CA, USA and 4Department of Physiology, Semmelweis University School of Medicine, Budapest, Hungary
ABSTRACT
Leukocyte recruitment into inflamed tissue is highly dependent on the activation and binding of integrins to their respective ligands, followed by the induction of various signaling events within the cell referred to as outside-in signaling. Src family kinases (SFK) are the central players in the outside-in signaling process, assigning them a critical role for proper immune cell function. Our study investigated the role of SFK on neutrophil recruit- ment in vivo using Hck-/- Fgr-/- Lyn-/- mice, which lack SFK expressed in neu- trophils. We show that loss of SFK strongly reduces neutrophil adhesion and post-arrest modifications in a shear force dependent manner. Additionally, we found that in the absence of SFK, neutrophils display impaired Rab27a- dependent surface mobilization of neutrophil elastase, VLA3 and VLA6 con- taining vesicles. This results in a defect in neutrophil vascular basement membrane penetration and thus strongly impaired extravasation. Taken together, we demonstrate that SFK play a role in neutrophil post-arrest mod- ifications and extravasation during acute inflammation. These findings may support the current efforts to use SFK-inhibitors in inflammatory diseases with unwanted neutrophil recruitment.
Introduction
Chronic inflammatory diseases are an increasing problem in western industrial- ized countries. A hallmark of these disorders is the recruitment of leukocytes from the circulation into affected tissues. This process follows a well-defined cascade of activation and adhesion events starting with the initial capture of leukocytes from the blood stream, followed by rolling along inflamed endothelium.1 Both steps are mediated by selectins interacting with glycosylated ligands on leukocytes.2 Through binding of the leukocyte specific integrin LFA1 (αLβ2) to ICAM-1 on endothelial cells, leukocytes slow down their rolling velocity, and in combination with chemokine stimulation, firmly arrest on the endothelial surface. This is fol- lowed by post-arrest modifications, a process characterized by cell spreading, cytoskeleton rearrangements and crawling along the endothelium, that is critical for tight adhesion to the substrate and allows an appropriate spot for extravasation into tissue. Transmigration involves the crossing of the venular wall and the under- lying vascular basement membrane (BM), two steps which are still incompletely understood. Several reports suggest a role for the integrins VLA3 (α3β1) and VLA6 (α6β1) along with neutrophil elastase (NE) in this process.3-5 Recently, our group has shown that neutrophils translocate VLA3, VLA6 and NE from internally stored vesicles to the cell surface, to subsequently cross the vascular BM.6 The release of these vesicles is initiated by interactions of neutrophils with the inflamed endothe- lium in a PECAM-1/ICAM-1- and CXCL1-dependent manner. Vesicle transport is
Correspondence:
MARKUS SPERANDIO
markus.sperandio@lmu.de
Received: April 29, 2019. Accepted: November 5, 2019. Pre-published: November 7, 2019.
doi:10.3324/haematol.2019.225722
Check the online version for the most updated information on this article, online supplements, and information on authorship & disclosures: www.haematologica.org/content/105/7/1845
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