Lai K N, Lockwood C M
Department of Medicine, University of Cambridge School of Clinical Medicine, England.
Clin Exp Immunol. 1991 Sep;85(3):396-401. doi: 10.1111/j.1365-2249.1991.tb05738.x.
The effect of anti-neutrophil cytoplasm autoantibodies (ANCA) on neutrophil activation was studied by pre-incubating neutrophils with IgG and F(ab')2 prepared from ANCA patients with Wegener's granulomatosis or microscopic polyarteritis. We measured the generation of inositol triphosphate (IP3) (a product of hydrolysis of membrane phospholipid which acts as a second intracellular messenger), and the translocation of protein kinase C (PKC) upon stimulation by a chemotactic peptide, fMet-Leu-Phe (fMLP). ANCA+ F(ab')2 did not induce a significant increase in IP3 generation. Nonetheless, ANCA+ F(ab')2 and ANCA+ IgG pretreatment of human neutrophils reduced the production of inositol phosphates upon subsequent fMLP stimulation compared with experiments performed when cells were pretreated with F(ab')2 and IgG prepared from ANCA- healthy subjects. A significantly reduced generation of IP3 and inositol biphosphate (IP2) was observed. ANCA+ F(ab')2 pretreatment of neutrophils inhibited fMLP-stimulated IP3 generation in a dose-dependent manner. The membrane-bound PKC activity upon stimulation by FMLP and PMA was reduced in neutrophils pretreated with ANCA+ F(ab')2 and IgG. These results indicate that ANCA affect in vitro signal transduction (IP3 generation, and translocation of PKC) in human neutrophils. Apparently, further activation of signal transduction by chemotactic peptide is significantly blunted in cells pre-incubated with ANCA+ F(ab')2 but not with F(ab')2 from healthy controls.
通过将中性粒细胞与从患有韦格纳肉芽肿或显微镜下多动脉炎的抗中性粒细胞胞浆自身抗体（ANCA）患者制备的IgG和F(ab')2预孵育，研究了ANCA对中性粒细胞活化的影响。我们测量了肌醇三磷酸（IP3）（膜磷脂水解产物，作为细胞内第二信使）的生成，以及趋化肽fMet-Leu-Phe（fMLP）刺激后蛋白激酶C（PKC）的转位。ANCA + F(ab')2未诱导IP3生成显著增加。尽管如此，与用从ANCA阴性健康受试者制备的F(ab')2和IgG预处理细胞时进行的实验相比，ANCA + F(ab')2和ANCA + IgG对人中性粒细胞的预处理降低了随后fMLP刺激时肌醇磷酸的产生。观察到IP3和肌醇二磷酸（IP2）的生成显著减少。中性粒细胞的ANCA + F(ab')2预处理以剂量依赖方式抑制fMLP刺激的IP3生成。用ANCA + F(ab')2和IgG预处理的中性粒细胞中，FMLP和PMA刺激后的膜结合PKC活性降低。这些结果表明，ANCA影响人中性粒细胞的体外信号转导（IP3生成和PKC转位）。显然，在与ANCA + F(ab')2预孵育的细胞中，趋化肽对信号转导的进一步激活明显减弱，但与健康对照的F(ab')2预孵育的细胞中则没有这种情况。
