CLA对仔猪外周血T淋巴细胞的细胞毒活性影响
Effects of dietary CLA on cytotoxic activity of peripheral blood lymphocyte cells of piglets

【目的】研究日粮中添加共轭亚油酸(Conjugated linoleic acid,CLA)对仔猪外周血T淋巴细胞的细胞毒活性影响，为将CLA作为免疫调节剂调控动物机体的免疫力和应用于畜禽乃至人类的营养实践提供参考。【方法】30头21日龄杜长大断奶健康仔猪按体质量相近、性别比例一致原则两两配对，随机分为对照组和CLA日粮组，分别喂给基础日粮和2%CLA日粮，每组5个重复，每个重复3头猪，63日龄时用肝素抗凝真空管前腔静脉采取血样，测定外周血T淋巴细胞亚群、细胞毒活性、穿孔素和颗粒酶B mRNA表达及脂肪酸组成。【结果】日粮添加CLA不影响仔猪外周血T淋巴细胞CD3+、CD4+的数量(P＞0.05)，但可显著提高CD8+T细胞总数(P＜0.05)；与对照组相比，CLA组仔猪外周血T淋巴细胞细胞毒活性、穿孔素和颗粒酶B mRNA表达分别提高29.98%(P＜0.01)，32.87%(P＜0.01)和43.36%(P＜0.01)；未添加CLA时，仔猪外周血T淋巴细胞几乎不含CLA，但CLA组仔猪外周血T淋巴细胞中CLA 含量达到 0.24% (P＜0.01) 。【结论】日粮添加2%CLA可提高仔猪外周血CD8+T淋巴细胞数，增强仔猪外周血T淋巴细胞细胞毒活性。
【Objective】This study investigated the effects of dietary conjugated linoleic acid (CLA) on cytotoxic activity of peripheral blood lymphocyte cells of piglets.【Method】Thirty Duroc×Large White×Landrace weaned piglets at age of 21 d were randomly allocated into two treatment groups and fed with control diet and 2% CLA diet,respectively.Each treatment had five replicates of 3 piglets.The blood samples were collected at the age of 63 d to detect peripheral blood lymphocyte subsets,lymphocyte cytotoxicity,mRNA expressions of perforin and granzyme B,and fatty acid composition of peripheral blood lymphocytes.【Result】Dietary CLA did not influence the numbers of CD3+ and CD4+T lymphocytes in peripheral blood of weaned piglets (P＞0.05),but significantly increased the number of CD8+T lymphocytes (P＜0.05).Dietary CLA increased cytotoxic activity,mRNA expressions of perforin and granzyme B in peripheral blood lymphocyte cells by 29.98% (P＜0.01),32.87% (P＜0.01) and 43.36% (P＜0.01),respectively.Peripheral blood lymphocyte cells of control group contained no CLA,but dietary CLA group had the total CLA content of up to 0.24% in peripheral blood lymphocyte cells (P＜0.01).【Conclusion】Supplement of 2% dietary CLA increased the number of peripheral blood CD8+T lymphocyte and enhanced cytotoxic activity of peripheral blood lymphocyte cells