Yousefi S, Hemmann S, Weber M, Hölzer C, Hartung K, Blaser K, Simon H U
Swiss Institute of Allergy and Asthma Research, Davos.
J Immunol. 1995 May 15;154(10):5481-90.
Eosinophils possess the capacity to synthesize various cytokines. We demonstrate that IL-8 mRNA and protein are constitutively expressed by freshly isolated resting human eosinophils. Most of the patients with bronchial asthma or atopic dermatitis show evidence for up-regulated IL-8 protein expression in eosinophils but not in neutrophils, suggesting that an eosinophil-specific cytokine may act in these patients. To investigate whether the intracellular IL-8 can be released, eosinophils were stimulated by different cytokines and platelet-activating factor. Priming with granulocyte-macrophage CSF and a subsequent 25-min stimulation with RANTES or platelet-activating factor resulted in release of IL-8 from highly purified human eosinophils in vitro. As the eosinophil is the predominant cell in asthmatic inflammation, we determined IL-8 concentrations in bronchoalveolar lavage fluids from normal individuals and asthmatic patients. Bronchoalveolar lavage fluids from patients with bronchial asthma consistently demonstrated high IL-8 concentration compared with the controls. This suggests that IL-8 is released in vivo by inflammatory bronchial cells in asthma.
嗜酸性粒细胞具有合成多种细胞因子的能力。我们证明，白细胞介素-8（IL-8）的信使核糖核酸（mRNA）和蛋白质由新鲜分离的静息人嗜酸性粒细胞组成性表达。大多数支气管哮喘或特应性皮炎患者显示嗜酸性粒细胞中IL-8蛋白表达上调，但中性粒细胞中未上调，这表明一种嗜酸性粒细胞特异性细胞因子可能在这些患者中起作用。为了研究细胞内的IL-8是否能够释放，用不同的细胞因子和血小板活化因子刺激嗜酸性粒细胞。先用粒细胞-巨噬细胞集落刺激因子（granulocyte-macrophage CSF）致敏，随后用调节激活正常T细胞表达和分泌的趋化因子（RANTES）或血小板活化因子刺激25分钟，可导致高度纯化的人嗜酸性粒细胞在体外释放IL-8。由于嗜酸性粒细胞是哮喘炎症中的主要细胞，我们测定了正常人和哮喘患者支气管肺泡灌洗液中的IL-8浓度。与对照组相比，支气管哮喘患者的支气管肺泡灌洗液始终显示出高浓度的IL-8。这表明在哮喘中，IL-8由炎症性支气管细胞在体内释放。
