[关键词]
[摘要]
研究嗜酸乳杆菌S-层蛋白对感染致病性大肠杆菌小鼠肠黏膜免疫的影响。用5 M的氯化锂溶液对嗜酸乳杆菌的S-层蛋白进行提取,获得脱除S-层蛋白的嗜酸乳杆菌菌体。将SPF级BALB/c小鼠随机分为对照组、致病性大肠杆菌感染组、嗜酸乳杆菌预防组治疗组,脱除S-层蛋白的嗜酸乳杆菌预防组和治疗组六组,实验进行14 d。小鼠处死后取眼球血、小肠及肠黏膜,观察各组小鼠肠黏膜形态变化、肠黏膜功能因子表达的差异。致病性大肠杆菌感染组与对照组相比,肠黏膜形态明显改变,感染大肠杆菌的小鼠在灌胃嗜酸乳杆菌后各黏膜SIgA和IL-10含量明显升高,同时血清IFN-γ、TNF-α和IL-1β含量对比感染组有了显著下降,说明可以减缓炎症发生,并且比脱除S-层蛋白的嗜酸乳杆菌治疗组对肠黏膜免疫保护效果好。嗜酸乳杆菌S-层蛋白对于嗜酸乳杆菌定植于肠黏膜并形成生物屏障保护其免疫功能有着重要影响。
[Key word]
[Abstract]
The influence of the S-layer protein of Lactobacillus acidophilus on the intestinal mucosal immune function in BALB/c mice infected with pathogenic Escherichia coli was investigated. Lactobacillus acidophilus cells without the S-layer protein was obtained using lithium chloride solution (5 M) to extract the S-layer protein from Lactobacillus acidophilus. The SPF grade BALB/c mice were randomly divided into six groups: control group, pathogenic Escherichia coli-infected group, Lactobacillus acidophilus prevention group, Lactobacillus acidophilus treatment group, Lactobacillus acidophilus without S-layer protein prevention group and Lactobacillus acidophilus without S-layer protein treatment group; the experiment was conducted for 14 days. After the mice were sacrificed, the eye blood, intestine, and intestinal mucosa of the mice were collected to examine the changes in morphology of the intestinal mucosa and the differences in the expression of functional factors in it. Compared with control group, the intestinal mucosal morphology changed significantly in pathogenic Escherichia coli-infected group. After the Escherichia coli-infected mice were administered Lactobacillus acidophilus by gavage, the SIgA and IL-8 contents in each mucosa were significantly increased, and the serum contents of TNF-α and IL-1β were significantly reduced compared with the infected group. The result indicated that Lactobacillus acidophilus can reduce the incidence of inflammation and has a better protective effect on the intestinal mucosal immune function than Lactobacillus acidophilus without the S-layer protein. The S-layer protein in Lactobacillus acidophilus plays an important role in its colonization in the intestinal mucosa and the formation of a biological barrier to protect the intestinal mucosal immune function.
[中图分类号]
[基金项目]
国家自然科学基金(31471598、41276121、31101314);江苏省自然科学基金(BK20141447);江苏省高校自然科学基金13KJB550013