Bassaganya-Riera J, Hontecillas R, Zimmerman D R, Wannemuehler M J
Department of Animal Science and Veterinary Medical Research Institute, Iowa State University, Ames, IA 50010, USA.
J Nutr. 2001 Sep;131(9):2370-7. doi: 10.1093/jn/131.9.2370.
In vivo vaccination and challenge studies have demonstrated that CD8(+) lymphocytes are essential for the development of cell-mediated protection against intracellular pathogens and neoplastic cells. Depletion of peripheral blood CD8(+) cells interferes with clearance of viruses and intracellular fungi, induction of delayed type hypersensitivity responses and antitumoral activity. In contrast to humans or mice, porcine peripheral CD8(+) lymphocytes are characterized by a heterogeneous expression pattern (i.e., CD8alphabeta and CD8alphaalpha) that facilitates the study of distinctive traits among minor CD8(+) cell subsets. A factorial (2 x 2) arrangement within a split-plot design, with 16 blocks of two littermate pigs as the experimental units for immunization treatment (i.e., unvaccinated or vaccinated with a proteinase-digested Brachyspira hyodysenteriae bacterin) and pig within block as the experimental unit for dietary treatment (soybean oil or conjugated linoleic acid) were used to investigate the phenotypic and functional regulation of CD8(+) cells by dietary conjugated linoleic acid (CLA). Dietary CLA supplementation induced in vivo expansion of porcine CD8(+) cells involving T-cell receptor (TCR)gammadeltaCD8alphaalpha T lymphocytes, CD3(-)CD16(+)CD8alphaalpha (a porcine natural killer cell subset), TCRalphabetaCD8alphabeta T lymphocytes and enhanced specific CD8(+)-mediated effector functions (e.g., granzyme activity). Expansion of peripheral blood TCRalphabetaCD8alphabeta cells was positively correlated (r = 0.89, P < 0.01) with increased percentages of CD8alphabeta(+) thymocytes. Functionally, CLA enhanced the cytotoxic potential of peripheral blood lymphocytes and proliferation of TCRgammadeltaCD8alphaalpha cells. Collectively, these results indicate that dietary CLA enhances cellular immunity by modulating phenotype and effector functions of CD8(+) cells involved in both adaptive and innate immunity.
体内接种疫苗和攻毒研究表明，CD8(+)淋巴细胞对于针对细胞内病原体和肿瘤细胞的细胞介导性保护的发展至关重要。外周血CD8(+)细胞的耗竭会干扰病毒和细胞内真菌的清除、迟发型超敏反应的诱导以及抗肿瘤活性。与人类或小鼠不同，猪外周CD8(+)淋巴细胞的特征是具有异质性表达模式（即CD8αβ和CD8αα），这便于研究次要CD8(+)细胞亚群之间的独特特征。采用裂区设计中的析因（2×2）安排，以16组两只同窝仔猪作为免疫治疗的实验单位（即未接种疫苗或接种蛋白酶消化的猪痢疾短螺旋体菌苗），以组内的猪作为饮食治疗的实验单位（大豆油或共轭亚油酸），来研究饮食共轭亚油酸（CLA）对CD8(+)细胞的表型和功能调节。饮食中补充CLA可在体内诱导猪CD8(+)细胞扩增，涉及T细胞受体（TCR）γδCD8αα T淋巴细胞、CD3(-)CD16(+)CD8αα（猪自然杀伤细胞亚群）、TCRαβCD8αβ T淋巴细胞，并增强特异性CD8(+)介导的效应功能（如颗粒酶活性）。外周血TCRαβCD8αβ细胞的扩增与CD8αβ(+)胸腺细胞百分比的增加呈正相关（r = 0.89，P < 0.01）。在功能上，CLA增强了外周血淋巴细胞的细胞毒性潜力以及TCRγδCD8αα细胞的增殖。总体而言，这些结果表明饮食CLA通过调节参与适应性免疫和固有免疫的CD8(+)细胞的表型和效应功能来增强细胞免疫。
