双歧杆菌完整肽聚糖对食物过敏小鼠调节性T细胞影响的研究

目的以食物过敏小鼠为动物模型,通过灌喂双歧杆菌完整肽聚糖(Whole Peptidoglycan,WPG),观察其对调节性T细胞的作用。方法 4～6周龄SPF级无鸡蛋喂养BALB/c雌鼠随机分为3组,每组8只。取其中2组建立食物过敏模型,分别为OVA致敏阳性对照组、OVA激发后灌喂双歧杆菌WPG治疗组和生理盐水对照组。采用ELISA法检测各组血清中OVA特异性IgE、IL-10和TGF-β1水平;流式细胞术分析脾脏单个核细胞悬液中CD4+CD25+调节性T细胞的数量变化。结果 OVA组IL-10、TGF-β1水平显著高于对照组(P分别0.05和0.01);WPG组血清IL-10和TGF-β1水平显著低于OVA组(P0.05)。OVA组脾CD4+CD25+T淋巴细胞的百分比低于对照组(P0.05),WPG组与OVA组相比有升高趋势,差异有统计学意义(P0.05);OVA组脾Foxp3+CD4+CD25+调节性T细胞的百分比显著低于对照组(P0.01),WPG组与OVA组相比有升高趋势,差异有统计学意义(P0.01)。结论双歧杆菌WPG可以增加食物过敏小鼠CD4+CD25+调节性T细胞数量,刺激细胞因子IL-10和TGF-β分泌。

Effect of whole peptidoglycan of bifidobacterium on food allergic mice′s regulatory T cells

Objective To observe the effect of whole peptidoglycan of bifidobacterium(WPG) on regulatory T cells in mice with food allergy.Methods Four-to six-week-old BALB/c SPF female mice fed on egg-free diets were randomly divided into three groups,8 mice per group,which were made the OVA group(positive control),WPG group and control group,respectively.The levels of the OVA-specific IgE,IL-10 and TGF-β in serum were measured by ELISA.The production of CD4+CD25+ Treg T cells in spleen mononuclear cell suspension was evaluated by Flow cytometry.Results The levels of IL-10 and TGF-β in OVA group were significantly higher compared with control group(P<0.05,P<0.01) and WPG group(P<0.05,P<0.01).The percentages of CD4+CD25+ T lymphocytes and Foxp3+CD4+CD25+ Treg T cells in OVA group decreased remarkably compared with control group(P<0.05,P<0.01),while that of WPG group increased significantly compared with OVA group(P<0.05,P<0.01).Conclusion WPG can increase the number of CD4+CD25+ Treg T cells of mice and stimulate the secretion of IL-10 and TGF-β.