Ly6G ligation blocks recruitment of neutrophils via a β2-integrin-dependent mechanism
Ly6G ligation blocks recruitment of neutrophils via a β2-integrin-dependent mechanism
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DOI：
10.1182/blood-2012-01-404046
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发表时间：
2012-08-16
期刊：
影响因子：
20.3
通讯作者：
Nigrovic, Peter A.
中科院分区：
文献类型：
--
作者：
Wang, Jun-Xia;Bair, Angela M.;Nigrovic, Peter A.
Ly 6 G是一种功能未知的糖基磷脂酰肌醇（GPI）锚定蛋白，通常靶向诱导小鼠实验性中性粒细胞耗竭。在本研究中，我们发现，剂量过低的抗Ly 6 G抗体产生持续的中性粒细胞减少症仍然能够抑制实验性关节炎，使关节组织无浸润性中性粒细胞。巯基乙酸盐刺激的腹膜炎也减弱。没有观察到中性粒细胞凋亡的改变，暗示招募受损。事实上，Ly 6 G连接废除了中性粒细胞向LTB 4和transwell系统中的其他化学引诱物的迁移。探索这种封锁的基础上，我们确定共定位Ly 6 G和β 2-整联蛋白的共聚焦显微镜，并确认密切相关的免疫共沉淀和荧光寿命成像显微镜。抗Ly 6 G抗体损害LTB 4刺激的中性粒细胞中β 2-整合素的表面表达，并模拟CD 11 a阻断，在流动条件下抑制ICAM-1结合和与活化内皮的牢固粘附。相应地，抗Ly 6 G不再抑制β 2整合素缺陷型中性粒细胞的迁移。这些结果表明，Ly 6 G的实验靶向对中性粒细胞群体具有功能性作用，并确定了Ly 6 G作为中性粒细胞通过β 2-整联蛋白依赖性机制迁移至炎症部位的调节剂的先前未被认识的作用。（血。2012;120（7）：1489-1498）
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)