Yamazaki M, Molski T F, Stevens T, Huang C K, Becker E L, Sha'afi R I
Department of Physiology, University of Connecticut Health Center, Farmington 06032.
Am J Physiol. 1991 Sep;261(3 Pt 1):C515-20. doi: 10.1152/ajpcell.1991.261.3.C515.
Preincubation of human neutrophils with the human hormone granulocyte-macrophage colony-stimulating factor (GM-CSF) inhibits the specific binding of leukotriene B4 ([3H]LTB4) but not the nonmetabolizable bioactive platelet-activating factor ([3H]C-PAF) to intact cells. This inhibition requires that the GM-CSF interacts with intact cells. The action of GM-CSF is not prevented by pertussis toxin. Moreover, the rise in calcium produced by LTB4 but not by PAF is also inhibited in human neutrophils pretreated with GM-CSF. Interestingly, neither the inhibitory action of GM-CSF on [3H]LTB4 binding or LTB4-induced calcium rise nor the potentiation of superoxide production by GM-CSF is reduced by inhibitors of arachidonic acid metabolism by the lipoxygenase pathway. In contrast, preincubation of human neutrophils with either the chemotactic factor formyl-methionyl-leucyl-phenylalanine (fMet-Leu-Phe) or the active phorbol ester, phorbol 12-myristate 13-acetate (PMA), inhibits the binding of both [3H]LTB4 and [3H]C-PAF to intact cells. The inhibitory actions of GM-CSF, PMA, and fMet-Leu-Phe require that they interact with the intact cells; their actions cannot be reproduced in plasma membrane preparations. The effects of both GM-CSF and fMet-Leu-Phe cannot be prevented by the protein kinase C inhibitor staurosporine. The mechanisms of fMet-Leu-Phe and GM-CSF actions are probably not mediated through the release of LTB4 by the cells. Interestingly, this new action, unlike other reported effects of GM-CSF, is not mediated through a pertussis toxin-sensitive G protein (Gi alpha 2). This indicates that not all GM-CSF receptors are coupled to Gi alpha 2.
人粒细胞巨噬细胞集落刺激因子（GM-CSF）与人中性粒细胞预孵育可抑制白三烯B4（[3H]LTB4）与完整细胞的特异性结合，但不影响不可代谢的生物活性血小板活化因子（[3H]C-PAF）与完整细胞的结合。这种抑制作用要求GM-CSF与完整细胞相互作用。百日咳毒素不能阻止GM-CSF的作用。此外，在经GM-CSF预处理的人中性粒细胞中，LTB4而非PAF所引起的钙升高也受到抑制。有趣的是，GM-CSF对[3H]LTB4结合或LTB4诱导的钙升高的抑制作用，以及GM-CSF对超氧化物产生的增强作用，均不会因脂氧合酶途径的花生四烯酸代谢抑制剂而减弱。相反，人中性粒细胞与趋化因子甲酰甲硫氨酰亮氨酰苯丙氨酸（fMet-Leu-Phe）或活性佛波酯佛波醇12-肉豆蔻酸酯13-乙酸酯（PMA）预孵育，可抑制[3H]LTB4和[3H]C-PAF与完整细胞的结合。GM-CSF、PMA和fMet-Leu-Phe的抑制作用要求它们与完整细胞相互作用；它们的作用在质膜制剂中无法重现。GM-CSF和fMet-Leu-Phe的作用均不能被蛋白激酶C抑制剂星形孢菌素所阻止。fMet-Leu-Phe和GM-CSF的作用机制可能不是通过细胞释放LTB4介导的。有趣的是，这种新作用与GM-CSF其他已报道的作用不同，它不是通过对百日咳毒素敏感的G蛋白（Giα2）介导的。这表明并非所有GM-CSF受体都与Giα2偶联。
