饮食限制对高脂饮食大鼠T细胞亚群的影响

EFFECTS OF DIETARY RESTRICTION ON T CELL SUBSETS IN HIGH-FAT DIET FED RATS

目的 了解饮食限制对高脂饮食诱导的肥胖大鼠血液及脾脏 T 细胞亚群的影响,探究节食与机体免疫机能的关联。方法 30 只 SPF 级的 6 w 龄雄性 SD 大鼠,适应性喂养 1 w 后,随机分为 3 组,其中一组作为普通对照组(NC)饲喂普通饲料,其余 2 组大鼠以高脂饲料喂养建立肥胖模型。当其体重超过 NC 组平均体重的 20%时,分为高脂饮食组(HF)和限制饮食组(HFR),NC 组饲喂普通饲料,HF 组饲喂高脂饲料,HFR 组采取 40%的饮食限制饲喂高脂饲料。8 w 后,用试剂盒检测大鼠血清的总胆固醇(total cholesterol, TC)、甘油三脂(triglyceride, TG)、白介素-1β(interleukin-1beta,IL-1β )和肿瘤坏死因子 α (tumor necrosis factor α ,TNFα )的含量;采用流式细胞仪检测血液及脾脏内的 CD3^(+)、CD4^(+)、CD8^(+)T 细胞百分比和 CD4^(+)/CD8^(+)的比值,以及脾脏内 CD4^(+)CD25^(+)Treg 细胞和 CD4^(+)Foxp3^(+)Treg细胞的表达率。结果 与 NC 组相比,HF 组大鼠的体重显著升高,血清 TC 含量显著增加,血液及脾脏 CD8^(+)T 细胞百分比显著增加(P<0.01),CD4^(+)/CD8^(+)的比值显著降低(P<0.01)CD4^(+)CD25^(+)Treg 细胞和 CD4^(+)Foxp3^(+)Treg 细胞的百分比显著降低(P<0.05);与 HF 组相比,HFR 组大鼠体重及脾脏重量显著降低,大鼠血清 IL-1β 显著增加,TNFα含量显著降低(P<0.05),血液及脾脏 CD8^(+)T 细胞的百分比显著降低(P<0.05),CD4^(+)/CD8^(+)的比值显著升高(P<0.05),CD4^(+)CD25^(+)Treg 细胞和 CD4^(+)Foxp3^(+)Treg 细胞的百分比没有显著变化。结论 饮食限制可以有效地逆转高脂饮食引起的肥胖大鼠血液及脾脏 T 细胞亚群的变化,改善肥胖大鼠的免疫机能。[营养学报,2022,44(5):479-483]

Objective To study the effect of dietary restriction on blood and spleen T cell subsets in high-fat diet-induced obese rats, and to explore the relationship between diet and immune function. Methods Thirty SPF 6-week-old Sprague-Dawley (SD) rats were randomly divided into 3 groups after one week of adaptive feeding. One group was fed a normal chow as the normal control group (NC), and the other 2 groups were fed a high-fat diet to establish obesity model.When their body weight exceeded 20% of the average body weight of the NC group, they were divided into a high-fat diet group (HF) and a restricted diet group (HFR). Then they were fed for 8 weeks. The NC group was fed the normal feed, and the HF group was fed the high-fat diet, and the HFR group was fed the high-fat diet with 40% dietary restriction. After 8weeks, serum total cholesterol (TC), triglyceride (TG), interleukin-1beta (IL-1β) and tumor necrosis factor alpha (TNFα)were analyzed using commercial kits. The contents of CD3^(+), CD4^(+), CD8^(+)T cells and the ratio of CD4^(+)/CD8^(+)in the blood and spleen, as well as the expression rate of CD4^(+)CD25^(+)Treg cells and CD4^(+)Foxp3Treg cells in the spleen were detected by flow cytometry. Results Compared with the NC group, the body weight of the rats in the HF group was significantly increased, while serum TC content, the percentage of CD8^(+)T cells in the blood and spleen, and the ratio of CD4^(+)/CD8^(+)were significantly decreased (P<0.01). The percentages of CD4^(+)CD25^(+)Treg cells and CD4^(+)Foxp3Treg cells were significantly decreased (P<0.05). Compared with the HF group, the body weight and spleen weight of the HFR group were significantly decreased, and serum IL-1β was significantly increased. The content of TNFα and the percentage of CD8^(+)T cells in the blood and spleen were significantly dec reased (P<0.05). The ratio of CD4^(+)/CD8^(+)was significantly increased (P<0.05).However, the percentages of CD4^(+)CD25^(+)Treg cells and CD4^(+)Foxp3Treg cells did not change significantly. Conclusion Dietary restriction can effectively reverse the changes of blood and spleen T cell subsets induced by the high fat diet,whereby the immune function of obese rats is improved. [ACTA NUTRIMENTA SINICA, 2022,44 (5):479-483]