Calder Philip C
Institute of Human Nutrition, School of Medicine, University of Southampton, IDS Building, MP887 Southampton General Hospital, Tremona Road, Southampton SO16 6YD, UK.
Prostaglandins Leukot Essent Fatty Acids. 2008 Sep-Nov;79(3-5):101-8. doi: 10.1016/j.plefa.2008.09.016. Epub 2008 Oct 23.
The immune system, including its inflammatory components, is fundamental to host defence against pathogenic invaders. It is a complex system involving interactions amongst many different cell types dispersed throughout the body. Central to its actions are phagocytosis of bacteria, processing of antigens derived from intracellular and extracellular pathogens, activation of T cells with clonal expansion (proliferation) and production of cytokines that elicit effector cell functions such as antibody production and killing cell activity. Inappropriate immunologic activity, including inflammation, is a characteristic of many common human disorders. Eicosanoids produced from arachidonic acid have roles in inflammation and regulation of T and B lymphocyte functions. Eicosapentaenoic acid (EPA) also gives rise to eicosanoids and these may have differing properties from those of arachidonic acid-derived eicosanoids. EPA and docosahexaenoic acid (DHA) give rise to newly discovered resolvins which are anti-inflammatory and inflammation resolving. Human immune cells are typically rich in arachidonic acid, but arachidonic acid, EPA and DHA contents can be altered through oral administration of EPA and DHA. This results in a changed pattern of production of eicosanoids and probably also of resolvins, although the latter are not well examined in the human context. Changing the fatty acid composition of immune cells also affects phagocytosis, T cell signaling and antigen presentation capability. These effects appear to mediated at the membrane level suggesting important roles of fatty acids in membrane order, lipid raft structure and function, and membrane trafficking. Thus, the fatty acid composition of human immune cells influences their function and the cell membrane contents of arachidonic acid, EPA and DHA are important. Fatty acids influence immune cell function through a variety of complex mechanisms and these mechanisms are now beginning to be unraveled.
免疫系统，包括其炎症成分，是宿主抵御病原体入侵的基础。它是一个复杂的系统，涉及遍布全身的许多不同细胞类型之间的相互作用。其作用的核心是细菌的吞噬作用、细胞内和细胞外病原体衍生抗原的处理、T细胞的激活与克隆扩增（增殖）以及细胞因子的产生，这些细胞因子引发效应细胞功能，如抗体产生和杀伤细胞活性。不适当的免疫活动，包括炎症，是许多常见人类疾病的特征。由花生四烯酸产生的类二十烷酸在炎症以及T和B淋巴细胞功能的调节中发挥作用。二十碳五烯酸（EPA）也会产生类二十烷酸，这些类二十烷酸可能具有与花生四烯酸衍生的类二十烷酸不同的特性。EPA和二十二碳六烯酸（DHA）会产生新发现的消退素，它们具有抗炎和促进炎症消退的作用。人类免疫细胞通常富含花生四烯酸，但通过口服EPA和DHA可以改变花生四烯酸、EPA和DHA的含量。这导致类二十烷酸的产生模式发生变化，可能消退素的产生模式也会改变，尽管后者在人类环境中的研究并不充分。改变免疫细胞的脂肪酸组成也会影响吞噬作用、T细胞信号传导和抗原呈递能力。这些影响似乎是在膜水平介导的，表明脂肪酸在膜秩序、脂筏结构和功能以及膜运输中起着重要作用。因此，人类免疫细胞的脂肪酸组成会影响其功能，花生四烯酸、EPA和DHA的细胞膜含量很重要。脂肪酸通过多种复杂机制影响免疫细胞功能，这些机制现在开始被揭示。
