内毒素休克猕猴白细胞介素18 mRNA变化规律的研究

Changes of interleukin-18 mRNA in lipopolysaccharide induced monkey endotoxic shock

目的 :研究猕猴实验性内毒素休克过程中 ,白细胞介素 18(IL 18)在外周血单个核细胞 (PBMC)、肝脏及脾脏中mRNA表达水平的变化规律。方法 :静脉注射细菌内毒素 (LPS) 2 8mg/kg制成内毒素休克模型 ,利用源自人细胞因子基因序列的引物 ,建立荧光半定量reversetranscription(RT) PCR方法 ,检测PBMCs、肝脏及脾脏中IL 18mRNA表达水平的改变 ,并与TNF α、IL 1β相对照。 结果 :LPS注射后 12 0分钟PBMC中IL 18的表达有显著增加 ,此时肝脏及脾脏中的mRNA表达水平也有增高 ;TNF α在PBMCs中mRNA水平于LPS注射后 6 0分钟即出现峰值 ,12 0分钟时肝脏和脾脏中的表达均显著增高 ;IL 1β在PBMCs中mRNA表达峰值出现在 6 0分钟 ,但 12 0分钟时在肝脏和脾脏中mRNA表达水平增高不明显。结论 :在猕猴实验性内毒素休克过程中IL 18的表达显著增高 ,但峰值晚于TNF α、IL 1β。IL 18可以由PBMCs和肝脏枯否细胞产生 (也许还有脾脏巨噬细胞 ) ;TNF α可能有广泛的细胞来源 ;IL 1β主要由PBMCs在LPS刺激活化后产生并分泌至血浆。

Objective:To evaluate the levels of interleukin 18(IL-18) mRNA in peripheral blood mononuclear cells(PBMCs),livers and spleens in monkey endotoxic shock models.Methods:Cynomolgus monkeys were injected i.v. with lipopolysaccharide(LPS) (2.8 mg/kg) to prepare the endotoxic shock models. The mRNA levels of IL-18 in PBMCs,livers and spleens were tested by fluorescence semi-quantitative realtime reverse transcription(RT)-PCR and compared with that of TNF-α and IL-1β.Results:IL-18 mRNA expression in PBMCs remarkably increased at 120 min after LPS administration, so did in livers and in spleens at the same time. mRNA levels of TNF-α in PBMCs peaked at 60 min after LPS injection, and also increased markedly at 120 min in livers and spleens. IL-1β mRNA levels peaked at 60 min in PBMCs, and did not change so much in livers and in spleens.Conclusion:IL-18 mRNA expression in PBMCs can be up-regulated by LPS, but changed latterly than TNF-α and IL-1β in endotoxic shock cynomolgus monkeys. It is presumed that IL-18 can be produced by PBMCs and liver Kupffer cells(maybe splenic macrophages),and TNF-α is produced by a variety of cells, but IL-1β in bloodstream mainly come from PBMCs after LPS challenge.