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目的：探讨沙眼衣原体（ Chlamydia trachomatis，Ct） pORF5质粒蛋白对IL-1β和IL-18等促炎性细胞因子的诱生作用，并初步分析其分子机制。方法：用0、3、6、12、24、36μg／ml不同浓度的pORF5蛋白刺激THP-1细胞，并于0、8、16、24、36 h收集上清及细胞，ELISA检测IL-1β和IL-18的含量；Realtime-PCR检测NALP3炎性复合体mRNA表达水平，Western blot鉴定Caspase-1活化状态；分别用NALP3 siRNA、ASC siRNA 转染THP-1细胞24 h或用Caspase-1特异性抑制剂（ Z-YVAD-FMK）预处理THP-1细胞30 min后，再用24μg／ml的pORF5质粒蛋白刺激THP-1细胞24 h，ELISA分析各处理因素对IL-1β和IL-18产生的影响。结果：pORF5质粒蛋白以浓度依赖的方式刺激THP-1细胞产生IL-1β和IL-18。当pORF5质粒蛋白浓度为24μg／ml时，IL-1β和IL-18的表达水平最高，分别为491 pg／ml、186 pg／ml；同时pORF5质粒蛋白以时间依赖的方式刺激THP-1细胞产生IL-1β和IL-18，两者分别在24 h和16 h达到峰值。 pORF5质粒蛋白可增强THP-1细胞NALP3、ASC 和Caspase-1 mRNA的表达，促进Caspase-1的活化；NALP3-siRNA、ASC-siRNA及Caspase-1抑制剂处理组IL-1β和IL-18的产生水平均显著低于对照组（ P＜0.05）。结论：pORF5质粒蛋白通过激活NALP3炎性复合体诱导THP-1细胞分泌IL-1β和IL-18。“,”Objective:To investigate whether pORF5 plasmid protein of Chlamydia trachomatis(Ct) induces 1L-1βand 1L-18 production in THP-1 cells,and its potential molecular mechanism.Methods:pORF5 plasmid protein was used to stimulate THP-1 cells at different concentrations(0,3,6,12,24,36 μg/ml),then the inflammatory cytokines IL-18 and IL-1βwere detected by ELISA at the time of 0,8,16,24,36 h;The mRNA expression of NALP3 inflammasome were detected by Realtime-PCR,and Caspase-1 activity was determined by Western blot analysis.THP-1 cells were transfected with siRNA targeting NALP3 and ASC gene for 24 h or pretreated with Caspase-1 inhibitor(Z-YVAD-FMK) for 30 min,and subsequently stimulated with pORF5(24 μg/ml) for 24 h,then secretion of IL-1βand IL-18 were analyzed by ELISA.Results: The pORF5 plasmid protein induced THP-1 cells to secrete IL-1βand IL-18 by dose-and time-dependent manners,production of IL-1βand IL-18 reached their peaks(491 pg/ml and 186 pg/ml) at concentration of 24 μg/ml,and the peak amount of IL-1βand IL-18 occurred at 24 h and 16 h post-stimulation respectively.pORF5 plasmid protein in-creased mRNA expression of NALP3 inflammasome and activated Caspase-1 in THP-1 cells.NALP3 siRNA,ASC siRNA and Z-YVAD-FMK reduced pORF5-induced IL-1βand IL-18 production when compared with control groups(P<0.05).Conclusion:pORF5 plasmid protein could induce THP-1 cells to produce IL-1βand IL-18 through NALP3 inflammasome activation,which may play an important role in the pathogenesis in Ct infection.