【摘要】 目的研究口服益生菌对鼠伤寒沙门菌(STM)感染小鼠Th细胞因子的影响,以探讨益生菌抗沙门菌感染的免疫学机制。方法将95只Balb/c小鼠分为4组,分别为益生菌组(P)、益生菌对照组(Pc)、正常感染组(I)和对照组(C)。P组口服益生菌,I组口服生理盐水,均予等剂量STM口服感染,Pc组接种益生菌但不感染STM,C组不作任何处理。各组动物在11个不同时点处死,观察小肠、肝脏、脾脏病理改变,ELISA测量血清IFN-γ、IL-4表达。结果益生菌组器官组织的病理改变轻微,IFN-γ较正常感染组明显增加(XP-I=66.52,P=0.001),且其表达在感染最初的1 h和后期的72 h分别出现两个高峰;IL-4明显降低(XP-I=-29.02,P<0.001),且较稳定。IFN-γ/IL-4比值扩大(XP-I=2.64,P<0.001)。结论口服益生菌使小鼠保持有利于抗STM感染的Th1型反应,减轻了STM对机体的免疫损伤。更多还原

【Abstract】 Objective To explore the effects of probiotics on the cytokine Th in Salmonella typhimurium( STM)-infected mice and discuss the immunological mechanism of the anti-STM infection role of probiotics. Methods 95 Balb /c mice were divided into probiotics( P) group,probiotics control( Pc) group,infection( I) group and control( C) group,respectively. The mice in group P were given orally probiotics,while the mice in group I were given orally saline; both groups were infected orally with S. thphimurium by equivalent dose. Mice in group Pc were orally given probiotics but not infected with STM. Mice in control group were untreated. All mice were sacrificed at a series of time points to observe pathological changes of spleen,liver and small intestine under a microscope. Serum interferon-γ( IFN-γ) and interleukin-4( IL-4) were detected with ELISA. Results In probiotics group,the expression of IFN-γ was significantly higher than in infection group( XP-I= 66. 52,P = 0. 001); Two distinct expression peaks of IFN-γ appeared at 1 h and 72 h after inoculation respectively; Pathological lesion of mice was mild; The expression of IL-4 was distinctly lower with significantly difference than in infection group( XP-I=-29. 02,P < 0. 001); The ratio of IFN-γ /IL-4 was increased( XP-I= 2. 64,P < 0. 001). The values of IFN-γ and IL-4 of probiotics control group and control group at all time points were not detectable. Conclusion Probiotics induced the expression level of serum IFN-γ,and decreased the expression level of serum IL-4 responding to STM infection in mice. Probiotics can promote immunological response against invaded pathogens and maintain suitable immunological response of organis.更多还原