Ly6G ligation blocks recruitment of neutrophils via a beta 2-integrin-dependent mechanism

作者:Wang Jun Xia; Bair Angela M; King Sandra L; Shnayder Ruslan; Huang Ya Fang; Shieh Chi Chang; Soberman Roy J; Fuhlbrigge Robert C; Nigrovic Peter A*
来源:Blood, 2012, 120(7): 1489-1498.
DOI:10.1182/blood-2012-01-404046

摘要

Ly6G is a glycosylphosphatidylinositol (GPI)-anchored protein of unknown function that is commonly targeted to induce experimental neutrophil depletion in mice. In the present study, we found that doses of anti-Ly6G Abs too low to produce sustained neutropenia remained capable of inhibiting experimental arthritis, leaving joint tissues free of infiltrating neutrophils. Thioglycollate-stimulated peritonitis was also attenuated. No alteration in neutrophil apoptosis was observed, implicating impaired recruitment. Indeed, Ly6G ligation abrogated neutrophil migration toward LTB4 and other chemoattractants in a transwell system. Exploring the basis for this blockade, we identified colocalization of Ly6G and beta 2-integrins by confocal microscopy and confirmed close association by both coimmunoprecipitation and fluorescence lifetime imaging microscopy. Anti-Ly6G Ab impaired surface expression of beta 2-integrins in LTB4-stimulated neutrophils and mimicked CD11a blockade in inhibiting both ICAM-1 binding and firm adhesion to activated endothelium under flow conditions. Correspondingly, migration of beta 2-integrin-deficient neutrophils was no longer inhibited by anti-Ly6G. These results demonstrate that experimental targeting of Ly6G has functional effects on the neutrophil population and identify a previously unappreciated role for Ly6G as a modulator of neutrophil migration to sites of inflammation via a beta 2-integrin-dependent mechanism. (Blood. 2012;120(7):1489-1498)

  • 出版日期2012-8-16