鼠伤寒沙门菌感染对小鼠Th1/Th2影响的动态研究

The changes of Th1/Th2 under Salmonella typhimurium infection in mice

目的研究鼠伤寒沙门菌(STM)感染的临床病理特征、机体在感染后的免疫应答反应特点以及沙门氏菌感染对Th反应平衡的影响,为临床相关疾病预防诊断和治疗提供依据。方法分别建立伤寒沙门菌感染和对照小鼠模型。两组动物在不同时点处死,观察小肠、肝脏、脾脏病理改变,流式细胞仪测量脾脏IFN-γ和IL-4表达,分别代表Th1和Th2细胞,计算Th1/Th2比值。结果感染伤寒沙门菌小鼠的小肠、肝脏、脾脏病理改变严重程度与对照组相比,在3天时最重,持续至第7天恢复到正常水平;小鼠接种鼠伤寒沙门菌后Th1/Th2比值明显升高,细胞分类向Th1细胞漂移,第3天时,Th1/Th2升到最高值,与病理改变程度和感染中毒症状一致。结论小鼠感染鼠伤寒沙门菌后,细胞分类向Th1漂移,产生炎症性损伤。

Objective To study the changes of Thl/Th2 under Salmonella typhimurium infection in mice Methods 24 BALB/c mice were randomly divided into 2 groups, including infection group and control group. The mice of infection group were orally infected with STM by a single dose, and were sacrificed on series time points. Spleen, liver and small intestine was observed with microscope, Interferon-γ （IFN-γ）and interleukin-4（IL-4） of splenocytes was detected with flow cytometry, which represented the numbers of Thl and Th2, respectively. Results Spleen, liver and small intestine was characterized by infiltrated with neutrophil leukocyte, monocyte and lmyphocyte. After 24 hours infection, the concentration of IFN-γ, in spleen began to increase, reached the peak at 3 day after infection. The increased IFN-γ, lasted for 5 days. The results indicated that the number of Thl was increased under infection. Conclusions After STM infection , cell immune response switched to Thl type immune response. The exacerbated inflammation in small intestine of host resulted from Thl cell immune increased in the early stage.