人嗜碱性粒细胞在不同刺激物作用下的组胺释放能力

目的:研究蛋白酶激活受体2(PAR2)激动剂和肝素等,对嗜碱性粒细胞组胺释放的影响。方法:用Ficoll进行密度梯度离心分离外周血单个核细胞(PBMC)。经Hank’s平衡盐溶液(HBSS)重新悬浮后进行嗜碱性粒细胞激发实验,用酶联免疫试剂盒来检测组胺的水平。结果:浓度为10mg/L胰蛋白酶可引起嗜碱性粒细胞释放组胺,其作用强度较抗IgE抗体、钙离子载体(CI)及P物质等为弱。PAR2特异性激动肽SLIGKVNH2对嗜碱性粒细胞没有明显的激活作用,但抗IgE抗体、CI、FMetLeuPhe(FMLP)、C5a及P物质可引起嗜碱性粒细胞显著的组胺释放。肝素、C5和腺苷在试验浓度内未引起组胺释放,但肝素可显著增加C5a和P物质诱导的组胺释放。结论:胰蛋白酶、抗IgE抗体、CI、FMLP、C5a及P物质均可诱导嗜碱性粒细胞显著地释放组胺。PAR2激动肽SLIGKVNH2不能引起组胺释放,肝素可增加P物质和C5a引起的组胺释放,具有放大嗜碱性粒细胞激活信号的作用。

Histamine release properties of human basophils in response to various stimuli

AIM: To investigate the effects of protease activated receptor-2 (PAR-2) agonist, heparin and other stimuli on histamine release from human basophils. METHODS: Peripheral blood mononuclear cells (PBMCs) were separated by density gradient centrifugation. The PBMCs were then resuspended in complete Hank's balanced salt solution (HBSS) and challenged with various stimulating agents. Histamine level in samples was determined by ELISA. RESULTS: 10 mg/L trypsin could induce histamine release from basophils. However, its stimulatory effect on basophils was weaker than that of anti-IgE, calcium ionophore (CI), F-Met-Leu-Phe (FMLP), C5a and substance P. PAR-2 agonist SLIGKV-NH(2) failed to activate basophils. Heparin, C5 and adenosine did not induce any histamine release at concentrations tested, but heparin enhanced histamine release induced by C5a and substance P. CONCLUSION: Trypsin, anti-IgE, CI, FMLP, C5a and substance P can induce histamine release from baosophils, but PAR-2 agonist can not. Heparin can greatly enhance the ability of C5a and substance P to stimulate histamine release, which may be a novel mechanism of amplification of basophil activation signal.