血小板第四因子（PF4）对人中性粒细胞粘附性与呼吸爆发的调节作用

目的：研究血小板第四因子（PF4）对人中性粒细胞（Np)功能的影响。方法：用结晶紫染色、免疫荧光标记、PKC试剂盒测定、NBT法及高香草酸（HVA）荧光分光光度法比较对照组与PF4作用的实验组在趋化因子刺激前后,PF4性粒细胞总粘附性、整合蛋白CD11b的表达、PKC水平及呼吸爆发作用产生活性氧物质（reactive oxygen species,ROS)O2^-、H2O2等的影响。结果：PF4对静息中性粒细胞总粘附性有轻度的增强作用,使总粘附性上调了12．24％（P＜0．01）,而对整合蛋白CD11b的表达、呼吸爆发产生的ROS（O2^-、H2O2）则无影响。进一步研究发现PF4使经趋化三肽（FMLP）活化的中性粒细胞的总粘附性下调17．47％（P＜0．01）;使经趋化三肽（FMLP）活化的中性粒细胞的整合蛋白CD11b的表达下调18．84％（P＜0．01）;使经佛波酯（PMA）活化的中性粒细胞的呼吸爆发作用产生的O2^-、H2O2分别下调了50．29％（P＜0．01）、226．53％（P＜0．05）。研究同时发现PF4对静息及活化的中性粒细胞的PKC水平均无影响。结论：首次证明PF4与其它经典的趋化因子不同,是中性粒细胞活化的一个负调节因子,对中性粒细胞功能主要起降调节的作用。这种降调卫作用不是通过PKC信号转导途径完成的。

Down regulatory effects of platelet factor four (PF4) on total adherence and respiratory burst of human neutrophil

Objective The effect of platelet factor four (PF4)on human neutrophil fun ction was studied.Methods Crystal violet dye staining,immunofluorescence labe ling,PKC kit assay,NBT and HVA flu-orospectrophotometry were applied to study the effect of PF4on total adherence,integrin CD11b level,PKC level and resp iratory burst level of resting human neutrophils and FMLP/or PMA-stimulated hu-m an neutrophils.Results It was found that PF4slightly increased the total adher ence of resting human neutrophils.There was no change on integrin CD11b level and respiratory burst level of rest-ing human neutrophils after interaction wit h PF4.However,PF4significantly down-regulated the total adh erence,integrin CD11b level and respiratory burst level of human neutrophils stimulated by FM LP/or PMA.In addition,PF4did not influence PKC level on resting and activate d human neutrophil.Conclusion These results indicate that PF4plays a down regu lation of the function of human neu-trophils.Differing from other members of cl assical CXC-chemokine family,the signaling of PF4is not through PLC-PKC signal pathway.