Dewald B, Thelen M, Baggiolini M
Theodor-Kocher-Institute, University of Bern, Switzerland.
J Biol Chem. 1988 Nov 5;263(31):16179-84.
The effects of 17-hydroxywortmannin (HWT), a powerful inhibitor of the respiratory burst associated with phagocytosis (Baggiolini, M., Dewald, B., Schnyder, J., Ruch, W., Cooper, P. H., and Payne, T. G. (1987) Exp. Cell Res. 169, 408-418), were studied in human neutrophils stimulated with chemotactic agonists or phorbol myristate acetate. At nanomolar concentrations HWT inhibited superoxide production and the release of granule contents induced by N-formyl-Met-Leu-Phe, C5a, platelet-activating factor, and leukotriene B4, but not by phorbol myristate acetate, indicating that it interferes with receptor-mediated activation of the neutrophils, without directly affecting protein kinase C (Ca2+/phospholipid-dependent enzyme), the NADPH-oxidase, or the process of granule exocytosis. Moreover, HWT did not influence agonist-induced [Ca2+]i changes, indicating that it does not interfere with the function of agonist receptors, G-proteins or the phosphatidylinositol-specific phospholipase C. By studying the effect of HWT on the respiratory burst elicited in normal and Ca2+-depleted cells by combined stimulation with N-formyl-Met-Leu-Phe and phorbol myristate acetate, evidence was obtained that two transduction sequences, both of which are G-protein-dependent, are necessary for the induction of the response by receptor agonists. One sequence is Ca2+-dependent, HWT-insensitive, and leads to activation of protein kinase C, the other is Ca2+-independent and HWT-sensitive. Ca2+ depletion, which blocks the first, and HWT, which blocks the second, can be used to show that both processes must be functional for the transduction of agonist signals into a respiratory burst response.
17-羟基渥曼青霉素（HWT）是一种与吞噬作用相关的呼吸爆发的强效抑制剂（巴焦利尼，M.，德瓦尔德，B.，施奈德，J.，鲁赫，W.，库珀，P.H.，以及佩恩，T.G.（1987年）《实验细胞研究》169卷，408 - 418页），本研究观察了其对用趋化激动剂或佛波酯肉豆蔻酸酯刺激的人中性粒细胞的影响。在纳摩尔浓度下，HWT抑制了由N-甲酰甲硫氨酰亮氨酰苯丙氨酸、C5a、血小板活化因子和白三烯B4诱导的超氧化物生成及颗粒内容物释放，但对佛波酯肉豆蔻酸酯诱导的无此作用，这表明它干扰了中性粒细胞的受体介导激活，而不直接影响蛋白激酶C（钙/磷脂依赖性酶）、NADPH氧化酶或颗粒胞吐过程。此外，HWT不影响激动剂诱导的细胞内钙离子浓度（[Ca2 +]i）变化，表明它不干扰激动剂受体、G蛋白或磷脂酰肌醇特异性磷脂酶C的功能。通过研究HWT对正常细胞和钙离子耗尽细胞经N-甲酰甲硫氨酰亮氨酰苯丙氨酸和佛波酯肉豆蔻酸酯联合刺激引发的呼吸爆发的影响，获得的证据表明，两条均依赖G蛋白的转导序列对于受体激动剂诱导反应是必需的。一条序列依赖钙离子，对HWT不敏感，导致蛋白激酶C激活；另一条序列不依赖钙离子，对HWT敏感。阻断第一条序列的钙离子耗尽和阻断第二条序列的HWT可用于表明，这两个过程对于将激动剂信号转导为呼吸爆发反应均必须发挥作用。
