SpA刺激单核巨噬细胞表达早期致炎因子的实验研究

Effect of staphylococcal protein A on pro-inflammatory cytokines expression in mononuclear macrophage

目的探讨金黄色葡萄球菌蛋白A(SpA)对单核巨噬细胞表达早期致炎因子TNF-α、IL-1和IL-6的影响。方法用一定浓度SpA与THP-1细胞培养不同时间,用MTT法测定SpA对THP-1细胞增殖的影响;用ELISA测定培养液中TNF-α、IL-1和IL-6的水平;用RT-PCR检测细胞TNF-α、IL-1和IL-6相应mRNA的表达,并对结果进行统计学分析。结果 SpA对THP-1细胞增殖的影响与其作用剂量有关。SpA可促进巨噬细胞分泌TNF-α、IL-1和IL-6及表达相应mRNA,且呈一定剂量-效应和时间-效应关系。SpA刺激巨噬细胞分泌TNF-α、IL-1、IL-6和表达相应mRNA均在12h达高峰。SpA刺激组TNF-α、IL-1和IL-6的表达和释放均显著升高(P<0.01)。结论 SpA可明显促进单核巨噬细胞表达和分泌早期致炎细胞因子TNF-α、IL-1和IL-6。SpA在启动金葡菌性脓毒症及促进其发展中,具有不可忽视的作用。

Objective To study the expression and regulation of pro-inflammatory cytokinesTNF-α,IL-1,IL-6in mononuclear macrophages stimulated with staphylococcal protein A（SpA）.Methods THP-1 was incubated with PMA and induced into mononuclear macrophages.Then the macrophages were incubated with varying concentrations of SpA under different time points.The effect of SpA on macrophage proliferation was measured by MTT method.The levels of inflammatory cytokines,TNF-α,IL-1and IL-6from the cultured cell media were measured by ELISA respectively.The levels of mRNA expression corresponding to TNF-α,IL-1and IL-6were detected by RT-PCR from the macrophages stimulated with SpA.All statistical analyses were performed by SPSS17.0software.Results The MTT result indicated that SpA had a positive effect on the proliferation of THP-1cells in a dosage depended manner.The addition of SpA could enhance the mRNA expression of TNF-α,IL-1and IL-6in the stimulated macrophages.It also showed a specific dose-effect and time-effect correlation.The macrophages secreted inflammatory cytokines and its corresponding mRNA reached its peak levels at 12 hpost stimulation.Compared with the control group,the expression and release of TNF-α,IL-1and IL-6in macrophages from the experimental group was increased with statistical significance（P〈0.01）.Conclusion SpA can promote the secretion and expression of early pro-inflammatory cytokines,such as TNF-α,IL-1and IL-6in macrophages.Therefore,SpA plays a very important role in the initiation and development of the staphylococcus aureus sepsis.