乳双歧杆菌诱导旋毛虫感染小鼠Th2型免疫应答的研究  

Study on Bifidobacterium lactis-induced Th2 immune response in mice infected with Trichinella spiralis

作　　者：迟茜文 姚梦玮 解文利 马翔宇 魏洪 CHI Qianwen;YAO Mengwei;XIE Wenli;MA Xiangyu;WEI Hong(Laboratory of Infection and Immunology,School of Basic Medicine,Guizhou Medical University,Guiyang 550025,Guizhou,China;Department of Microbiology,School of Basic Medicine,Guizhou Medical University,Guiyang 550025,Guizhou,China)

机构地区：[1]贵州医科大学基础医学院感染与免疫学实验室,贵州贵阳550025 [2]贵州医科大学基础医学院微生物学教研室,贵州贵阳550025

出　　处：《贵州医科大学学报》2024年第11期1631-1638,共8页Journal of Guizhou Medical University

基　　金：2021年国家大学生创新创业训练计划项目(202110660001X)。

摘　　要：目的探究不同剂量乳双歧杆菌干预对旋毛虫感染小鼠的淋巴细胞增殖、辅助型T细胞2(Th2)型免疫和肠道损伤的影响。方法用活力良好的旋毛虫灌胃48只小鼠获得感染旋毛虫模型小鼠,随机分为感染组(0.02 mL/g PBS灌胃)、乳双歧杆菌(高、中、低)剂量组(乳双歧杆菌浓度分别为1×10^(6)、1×10^(5)、1×10^(4) CFU/L,0.02 mL/g灌胃)连续灌胃30 d;采用噻唑蓝(MTT)法检测第7、14、21、28天各组模型小鼠脾细胞中T淋巴细胞增殖水平,流式细胞术检测小鼠脾脏及肠系膜淋巴结中CD4^(+)T细胞、CD8^(+)T细胞表达水平,苏木精-伊红(HE)染色法对十二指肠组织病理学进行观察。结果与感染组比较,高剂量组、中剂量组脾脏T淋巴细胞的刺激指数(SI)升高(P<0.05);与感染组相比,小鼠脾脏中乳双歧杆菌高剂量组第14、21天脾脏中CD4^(+)T细胞表达升高,第21天乳双歧杆菌高剂量组表达CD8^(+)T细胞降低,小鼠肠系膜淋巴结中乳双歧杆菌高剂量组、中剂量组CD4^(+)T细胞表达增加(P<0.05);HE结果显示;与感染组比较,乳双歧杆菌高剂量乳双歧杆菌灌胃后第7天和14天炎性细胞浸润减轻,肠绒毛脱落减少。结论一定浓度的乳双歧杆菌能够提高小鼠抗旋毛虫感染的免疫效应,其机制可能与通过诱导小鼠趋向Th2型免疫极化、修复肠道病理损伤有关。Objective To investigate the effects of different doses of Bifidobacterium lactis on lymphocyte proliferation,thelper 2 cell(Th2)immunity and intestinal injury in mice infected with Trichinella spiralis.Methods A total of 48 mice infected with T.spiralis model were obtained by gavage with vibrant and energetic strains of the bacterium,randomly divided into infection group(0.02 mL/g PBS gavage),high dose-,medium dose-and low dose-B.lactis groups(1×10^(6),1×10^(5),and 1×10^(4) CFU/L and 0.02 mL/g gavage,respectively)for 30 continuous day gavage.Thiazolyl blue(MTT)assay was used to detect the proliferation levels of T lymphocytes in mouse splenocytes of model mice on days 7 th,14 th,21 st,and 28 th.Flow cytometry was applied to detect the level of CD4^(+)T cells and CD8^(+)T cells in spleen and mesenteric lymph nodes.Hematoxylin-eosin(HE)staining was used to observe duodenum histopathology.Results When compared to infection group,stimulation indexes(SI)of splenic T lymphocytes were increased in high dose-and medium dose-groups(P<0.05).When compared to infection group,high dose group of B.lactis showed an increase in CD4^(+)T cell expression in the spleen on days 14 th and 21 st.On day 21 st,there was a decrease in CD8^(+)T cell expression in high-dose group of B.lactis and an increase in CD4^(+)T cell expression in mouse mesenteric lymph nodes in high dose-and medium dose-groups(P<0.05).When compared to infection group,high-dose administration of B.lactis resulted in reduced inflammatory cell infiltration and decreased shedding of intestinal villi on days 7 th and 14 th.Conclusion A certain concentration of B.lactis can enhance the immune response of mice against T.spiralis infection.Its mechanism may be related to inducing Th2 immune polarization and repairing mouse intestinal pathological damage.

关 键 词：乳双歧杆菌 旋毛虫 T淋巴细胞 淋巴细胞增殖 Th2型免疫 免疫保护 

分 类 号：R383.1[医药卫生—医学寄生虫学]