Adamko Darryl J, Wu Yingqi, Ajamian Farnam, Ilarraza Ramses, Moqbel Redwan, Gleich Gerald J
Department of Pediatrics, Pulmonary Research Group, University of Alberta, Edmonton, Alberta, Canada.
J Allergy Clin Immunol. 2008 Aug;122(2):383-90, 390.e1-4. doi: 10.1016/j.jaci.2008.03.020. Epub 2008 May 2.
In patients with atopic diseases, cationic-charged eosinophil proteins are deposited in inflamed tissues. Although the role of cytokines in cell activation is well established, the presence of cationic-charged tissue can also be an important factor in inflammatory cell function.
We sought to determine whether increased cationic charge seen in an atopic microenvironment plays a role in the activation of eosinophils.
Human eosinophils were incubated with Sepharose beads coated with cationic or anionic compounds in the presence and absence of a cytokine cocktail (IL-3, IL-5, and GM-CSF) to simulate the milieu of inflammation. Eosinophil peroxidase and eosinophil-derived neurotoxin (EDN) release were compared with eosinophil morphology and expression of CD18, as determined by means of confocal microscopy.
Cytokines with positively charged beads caused greater eosinophil peroxidase release (lysine coated, 44.2 nmol/L; compound 48/80, 40.0 nmol/L; or EDN coated, 49.1 nmol/L) than cytokines alone (14.9 nmol/L). Beads coated with heparin, dextran sulfate, and aspartic acid did not show this effect. EDN release was also induced by lysine-coated beads with cytokines (67.1 ng/100 microL) and blocked by heparin. Eosinophil incubation with wortmannin, genistein, and the src kinase inhibitor PP1 blocked cationic signaling. Eosinophils adherent to cationic-charged beads but not anionic-charged beads show polarization of CD18 expression toward the bead's surface.
Cationic-charged surfaces induce increased eosinophil mediator release by increasing the density of CD18 expression available at the target surface.
在特应性疾病患者中，带阳离子电荷的嗜酸性粒细胞蛋白沉积于炎症组织中。尽管细胞因子在细胞活化中的作用已得到充分证实，但带阳离子电荷的组织的存在也可能是影响炎症细胞功能的一个重要因素。
我们试图确定在特应性微环境中观察到的阳离子电荷增加是否在嗜酸性粒细胞的活化中起作用。
在存在和不存在细胞因子混合物（IL-3、IL-5和GM-CSF）的情况下，将人类嗜酸性粒细胞与包被有阳离子或阴离子化合物的琼脂糖珠一起孵育，以模拟炎症环境。通过共聚焦显微镜观察，比较嗜酸性粒细胞过氧化物酶和嗜酸性粒细胞衍生神经毒素（EDN）的释放情况以及嗜酸性粒细胞形态和CD18的表达。
带正电荷的珠子与细胞因子一起导致嗜酸性粒细胞过氧化物酶释放量增加（赖氨酸包被的，44.2 nmol/L；化合物48/80，40.0 nmol/L；或EDN包被的，49.1 nmol/L），高于单独使用细胞因子时（14.9 nmol/L）。包被有肝素、硫酸葡聚糖和天冬氨酸的珠子未显示出这种效应。赖氨酸包被的珠子与细胞因子一起也诱导了EDN释放（67.1 ng/100 μL），并被肝素阻断。用渥曼青霉素、染料木黄酮和src激酶抑制剂PP1孵育嗜酸性粒细胞可阻断阳离子信号传导。附着于带阳离子电荷珠子而非带阴离子电荷珠子的嗜酸性粒细胞显示CD18表达向珠子表面极化。
带阳离子电荷的表面通过增加靶表面可用的CD18表达密度诱导嗜酸性粒细胞介质释放增加。
