Galectin-9 mediates neutrophil capture and adhesion in a CD44 and ß2 integrin-dependent manner.
FASEB J
; 36(1): e22065, 2022 01.
Article
em En
| MEDLINE
| ID: mdl-34847625
ABSTRACT
Neutrophil trafficking is a key component of the inflammatory response. Here, we have investigated the role of the immunomodulatory lectin Galectin-9 (Gal-9) on neutrophil recruitment. Our data indicate that Gal-9 is upregulated in the inflamed vasculature of RA synovial biopsies and report the release of Gal-9 into the extracellular environment following endothelial cell activation. siRNA knockdown of endothelial Gal-9 resulted in reduced neutrophil adhesion and neutrophil recruitment was significantly reduced in Gal-9 knockout mice in a model of zymosan-induced peritonitis. We also provide evidence for Gal-9 binding sites on human neutrophils; Gal-9 binding induced neutrophil activation (increased expression of ß2 integrins and reduced expression of CD62L). Intra-vital microscopy confirmed a pro-recruitment role for Gal-9, with increased numbers of transmigrated neutrophils following Gal-9 administration. We studied the role of both soluble and immobilized Gal-9 on human neutrophil recruitment. Soluble Gal-9 significantly strengthened the interaction between neutrophils and the endothelium and inhibited neutrophil crawling on ICAM-1. When immobilized, Gal-9 functioned as an adhesion molecule and captured neutrophils from the flow. Neutrophils adherent to Gal-9 exhibited a spread/activated phenotype that was inhibited by CD18 and CD44 neutralizing antibodies, suggesting a role for these molecules in the pro-adhesive effects of Gal-9. Our data indicate that Gal-9 is expressed and released by the activated endothelium and functions both in soluble form and when immobilized as a neutrophil adhesion molecule. This study paves the way for further investigation of the role of Gal-9 in leukocyte recruitment in different inflammatory settings.
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Base de dados:
MEDLINE
Assunto principal:
Antígenos CD18
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Receptores de Hialuronatos
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Galectinas
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Migração Transendotelial e Transepitelial
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Células Endoteliais da Veia Umbilical Humana
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Neutrófilos
Limite:
Animals
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Humans
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article