论文部分内容阅读
目的探讨鼠巨细胞病毒(MCMV)感染对小鼠脾细胞内TH1细胞调控因子白细胞介素-12(IL-12)p35和p40基因转录和表达影响的时序性变化特点。方法制备全身播散型MCMV感染小鼠模型,于感染后3 d、5 d、7 d、10 d和14 d分离小鼠脾细胞,在PHA刺激后用RT-PCR法检测脾细胞内IL-12 p35和p40 mRNA水平时序性变化,ELISA法测定脾细胞培养上清中IL-12 p70和IFN-γ蛋白水平变化。结果模型鼠在感染后第3天IL-12 p70表达显著增高(P<0．05),但第5天后急剧下降,显著低于正常鼠(P<0．05);IFN-γ在感染后第3天增高达峰值(P<0．01),随后逐渐下降,在感染后第10-14天降至正常水平;IL-12 p35 mRNA水平变化与IL-12 p70完全一致;而p40 mRNA则从感染第3天开始持续高水平表达(P<0．01)。结论IL-12 p35 mRNA和IL-12 p70在感染5 d后持续明显下降是感染后期TH1类细胞因子持续低表达、TH1反应受抑制的主要原因之一;感染后IL-12 p40 mRNA持续高水平可能导致拮抗剂(p40)2表达增加,后者可进一步抑制IL-12功能。
Objective To investigate the effects of cytomegalovirus (MCMV) infection on the transcription and expression of interleukin-12 (p35) and p40 (p40) genes in TH1 cells in mice. Methods The mouse model of MCMV infection was established and the splenocytes of mice were isolated on the 3rd, 5th, 7th, 10th and 14th day after infection. The expressions of IL- 12 p35 and p40 mRNA levels of temporal changes, ELISA assay of spleen cell culture supernatant IL-12 p70 and IFN-γ protein levels. Results The expression of IL-12 p70 was significantly increased (P <0.05) on the 3rd day after infection in the model mice, but dropped sharply after 5 days, significantly lower than that in the normal mice (P <0.05). After IFN- (P <0.01), and then decreased gradually to the normal level from the 10th to 14th day after infection. The level of IL-12 p35 mRNA in IL-12 was exactly the same as that of IL-12 p70 From the third day of infection, sustained high level expression (P <0.01). Conclusions The continuous decrease of IL-12 p35 mRNA and IL-12 p70 mRNA after 5 days of infection is one of the main reasons for the persistent low expression of TH1 cytokines and the suppression of TH1 responses in the late stage of infection. IL-12 p40 mRNA continues to be high after infection May result in increased expression of antagonist (p40) 2, which may further inhibit IL-12 function.