中文摘要：

目的：廿烷五烯酸可以通过改变免疫细胞膜的组成，细胞内信使和细胞因子来调节免疫细胞的功能，研究廿烷五烯酸对机体免疫功能的影响，并探索其作用机制。 资料来源：应用计算机检索Pubmed和Medscape数据库1990-01／2004-12的相关文章，检索词“EPA，Immune Function”，并限定文章语言种类为英文。同时计算机检索中国期刊全文数据库2000-01／2004-12的相关文章，检索词“廿烷五烯酸，免疫功能”，并限定文章语言种类为中文。 资料选择：对资料进行初审，并查看每篇文献后的引文。纳入标准：文章所述内容应与廿烷五烯酸影响免疫功能研究相关。排除标准：重复研究或Meta分析类文章。 资料提炼：共收集到54篇相关文献，22篇文献符合纳入标准，排除的32篇文献是由于内容陈旧或重复等。 资料综合：n-3脂肪酸属必需脂肪酸，包括廿烷五烯酸。大量研究证实，廿烷五烯酸能影响免疫功能，预防疾病的发生。廿烷五烯酸能够抑制啮齿动物淋巴组织（淋巴结、脾和胸腺）中淋巴细胞增生及人外周血淋巴细胞在丝裂原刺激下的增生，可以直接影响巨噬细胞的功能。影响细胞膜磷脂脂肪酸的构成及酶作用，通过影响细胞膜的流动性、信号转导及基因表达调节免疫功能。 结论：廿烷五烯酸通过置换细胞膜磷脂中的花生四烯酸，竞争环氧酶和脂氧合酶从而影响免疫反应，廿烷五烯酸通过改变细胞膜磷脂脂肪酸的构成来影响细胞膜的流动性，膜上相关信号分子、酶、受体的功能，从而改变信号转导过程。此外，通过影响酶或细胞因子的基因表达．抑制促炎症因子产生、调节黏附分子的表达来调节免疫功能。

英文摘要：

OBJECTIVE： Eicosapentaenoic acid （EPA） can modulate immunocyte function by changing intraeellnlar messenger, cytokines and composition of cell membrane. In this paper, we explore the effect of EPA on immune function and its mechanism. DATA SOURCES： We searched the Pubmed and Medscape database for relative English articles published from January 1990 to December 2004, using the key words of ＂EPA, Immune Function＂. Meanwhile, a computerbased online research of China Journal Full-Text Database was undertaken for relative Chinese articles published from January 2000 to December 2004 with the same keywords in Chinese. STUDY SELECTION： Articles were selected firstly, and the citations of every article were looked over. Inclusive criteria： The articles about immune function of EPA. Exclusive criteria： The repetitive research or Meta analysis articles. DATA EXTRACTION： A total of 54 related articles were collected, in which 22 articles met the inclusive criteria, and 32 old or repetitive articles were excluded. DATA SYNTHESIS： The n-3 fatty acid belongs to essential fatty acids, which includes EPA. Many researches have proved that EPA can affect immune function and prevent diseases. EPA can inhibit the hyperplasia of lymphocyte in lymphatic tissue （lymph node, spleen and thymus） of rodent animals and hyperplasis of human peripheral blood lymphocyte under the stimulus of mitogen, which can influence the macrophage function directly and composition of the fatty acid in membrane phospholipid as well as enzyme action. EPA can also modulate immune function by influencing the fluidity of membrane, signal transmitting and genetic expression. CONCLUSION： EPA can influence immunoreactions by replacement of arachidonic acid in membrane phospholipid, competition of cyclooxygenase and lipoxygenase, and it can also affect the fluidity of membrane and functions of relative signal molecule, enzyme and receptor by changes of fatty acid in membrane phospholipid, so as to change the signal transmitting.