Roberts P J, Devereux S, Pilkington G R, Linch D C
Department of Haematology, Faculty of Clinical Science, University College London, U.K.
J Leukoc Biol. 1990 Sep;48(3):247-57. doi: 10.1002/jlb.48.3.247.
Freshly purified neutrophils and monocytes respond to multiple cross-linking of Fc gamma RII with the IgG1 monoclonal antibody, CIKM5, with a rapid rise in Ca(2+)i, but not with a respiratory burst, although superoxide is generated by these cells when stimulated with the chemotactic peptide, FMLP, or phorbol ester (TPA). Incubation in vitro for 30-60 min at 37 degrees C in medium + 0.1% FCS had no effect on the neutrophil superoxide response to CIKM5 but induced a weak monocyte response in 11/13 experiments. However, incubation with rhGM-CSF (10 ng/ml) under similar conditions induced a neutrophil respiratory burst in response to cross-linking Fc gamma RII in 12/14 experiments and enhanced the monocyte response by 181%. GM-CSF also enhanced the response of neutrophils and monocytes to FMLP by 308% and 165%, respectively. The response to TPA was not significantly enhanced by GM-CSF. rhIFN-gamma (100 mu/ml) was ineffective as a priming agent for all agonists tested in short-term incubations but augmented the monocyte response to CIKM5 after 5 d exposure in vitro. Whilst GM-CSF induced neutrophil superoxide production in response to cross-linking Fc gamma RII, there was no concomitant change in Fc gamma RII expression either in in vitro studies of neutrophils from healthy individuals or in in vivo studies of patients receiving GM-CSF. Stimulation of unprimed neutrophils with CIKM5 induced a rapid transient increase in intracellular calcium levels to 181% of resting levels. However, incubation with GM-CSF did not further augment the calcium transients above the stimulated level. The mechanism by which GM-CSF induces an enhanced respiratory burst in response to cross-linking of Fc gamma RII remains to be elucidated, but is not related to receptor expression or increases in receptor mediated calcium mobilization.
新鲜纯化的中性粒细胞和单核细胞对FcγRII与IgG1单克隆抗体CIKM5的多次交联反应表现为细胞内钙离子浓度（Ca(2+)i）迅速升高，但不会引发呼吸爆发，尽管这些细胞在用趋化肽FMLP或佛波酯（TPA）刺激时会产生超氧化物。在含有0.1%胎牛血清（FCS）的培养基中于37℃体外孵育30 - 60分钟，对中性粒细胞对CIKM5的超氧化物反应没有影响，但在13个实验中有11个实验诱导出了较弱的单核细胞反应。然而，在类似条件下用重组人粒细胞-巨噬细胞集落刺激因子（rhGM-CSF，10 ng/ml）孵育，在14个实验中有12个实验中，中性粒细胞在FcγRII交联时引发了呼吸爆发，并且单核细胞反应增强了181%。GM-CSF还分别使中性粒细胞和单核细胞对FMLP的反应增强了308%和165%。GM-CSF对TPA的反应没有显著增强。重组人干扰素-γ（rhIFN-γ，100 μ/ml）在短期孵育中作为所有测试激动剂的预激剂无效，但在体外暴露5天后增强了单核细胞对CIKM5的反应。虽然GM-CSF诱导中性粒细胞在FcγRII交联时产生超氧化物，但在健康个体中性粒细胞的体外研究或接受GM-CSF治疗患者的体内研究中，FcγRII的表达均没有伴随变化。用CIKM5刺激未预激的中性粒细胞会导致细胞内钙水平迅速短暂升高至静息水平的181%。然而，与GM-CSF孵育并没有使钙瞬变在刺激水平之上进一步增强。GM-CSF诱导FcγRII交联时呼吸爆发增强的机制仍有待阐明，但与受体表达或受体介导的钙动员增加无关。
