Sasaki T, Kanke Y, Kudoh K, Misawa Y, Shimizu J, Takita T
Department of Bioregulation Studies, Graduate School of Agriculture, Tokyo University of Agriculture, Japan.
Biochim Biophys Acta. 1999 Jan 4;1436(3):519-30. doi: 10.1016/s0005-2760(98)00162-3.
It is known that n-3 polyunsaturated fatty acids (PUFA) such as docosahexaenoic acid (DHA) suppress immunity as compared with n-6 PUFA such as linoleic acid (LA), but the mechanism involved in this phenomenon is still unclear. The present study was designed to assess the effect of dietary DHA on the surface molecules involved in T cell proliferation. Weanling male C57BL/6 mice were divided into four dietary groups that were fed a 10% fat diet for 4 weeks varying in amounts of DHA and LA. As the dietary DHA concentration increased, the surface expression of CD4 and CD8 on splenic T cells decreased, while that of CD28 increased. The surface expression of CD3, however, was invariable in all dietary groups. DNA synthesis of splenic T cells, induced by CD3 crosslinkage with anti-CD3 epsilon monoclonal antibody in the presence of CD28-mediated costimulation, increased as the DHA concentration was elevated. These observations suggest that diets rich in DHA exert some of their immunomodulatory effects by a downregulation of surface expression of CD4 and CD8 and by an upregulation of CD28-mediated costimulatory signal.
已知与n-6多不饱和脂肪酸（PUFA）如亚油酸（LA）相比，n-3多不饱和脂肪酸（PUFA）如二十二碳六烯酸（DHA）会抑制免疫，但这种现象所涉及的机制仍不清楚。本研究旨在评估膳食DHA对参与T细胞增殖的表面分子的影响。将断乳雄性C57BL/6小鼠分为四个膳食组，给予含10%脂肪的饮食，持续4周，膳食中DHA和LA的含量各不相同。随着膳食DHA浓度的增加，脾脏T细胞上CD4和CD8的表面表达下降，而CD28的表面表达增加。然而，CD3的表面表达在所有膳食组中均无变化。在CD28介导的共刺激存在下，用抗CD3ε单克隆抗体交联CD3诱导的脾脏T细胞DNA合成随着DHA浓度的升高而增加。这些观察结果表明，富含DHA的饮食通过下调CD4和CD8的表面表达以及上调CD28介导的共刺激信号来发挥其一些免疫调节作用。
