多不饱和二十二碳六烯酸对白细胞介素-2α受体的抑制作用  

Suppressive effect of docosa hexaenorc acid on IL-2α receptor

作　　者：李秋荣[1] 马健[1] 施谦[1] 汪灏[1] 黎介寿[1] 

机构地区：[1]南京军区南京总医院解放军普通外科研究所,江苏南京210002

出　　处：《肠外与肠内营养》2004年第6期324-328,共5页Parenteral & Enteral Nutrition

基　　金：国家重点基础研究发展规划项目资助 ( 2 0 0 3CB5 15 5 0 2 ) ;军区"十五"面上课题基金资助 ( 2 0 0 40 3 4)项目

摘　　要：目的 :研究多不饱和二十二碳六烯酸 (DHA)可通过改变IL 2α受体在细胞膜亚区域的分布和免疫抑制调节。　方法 :用DHA(2 2∶6 )处理JurkatE6 1T细胞 ,硬脂酸 (18∶0 )处理作为阴性对照。应用流式细胞仪检测DHA对T细胞表面分子CD2 5 (IL 2Rα)表达的抑制作用。超速离心分离T细胞膜脂肪微区域 ,应用蛋白印迹法分析检测IL 2Rα所在的T细胞膜亚区域组分 ,与硬脂酸处理相比较 ,分析DHA处理对T细胞膜不同亚区域IL 2Rα分布的影响。　结果 :流式细胞仪检测表明 ,对照组 75 μmol/L硬脂酸处理 ,检测到细胞表面CD2 5阳性表达细胞率为 4 0 .14 % ,75 μmol/LDHA处理T细胞 ,细胞表面CD2 5阳性表达细胞率为 19.2 8% ,DHA可抑制T细胞表面分子CD2 5的表达。蛋白印迹法分析确定IL 2Rα存在于rafts组分中 ,DHA处理使部分IL 2Rα从膜rafts区域移位到可溶膜区域。　结论 :膜脂肪微区域为IL 2受体信号转导的功能性亚区域 ,DHA通过调节IL 2Rα在膜脂肪微区域的分布 ,使部分IL 2Rα从功能性rafts区域移位到非功能性可溶膜区域 ,而产生免疫抑制作用。Objective: The objective was to determine that IL-2Rα was associated with lipid rafts of T cells and docosahexaenoic acid (DHA) exerted effectively immunosuppressive function probably by altering distribution of IL-2Rα in membrane subdomains. Methods: The human Jurkat E6-1 T cells were cultured in DHA-supplemented culture medium and the cells treated with stearic acid served as a control. The effect of DHA on CD25(IL-2Rα) expression on the surface of T cells was performed. Lipid rafts were isolated by discontinuous sucrose density gradient ultracentrifugation. The localization of IL-2Rα in fractions was determined by immunoblot and detected by chemiluminescence. The alteration of IL-2Rα in different fractions of plasma membrane in DHA-treated cells was determined. Results: DHA suppressed CD25 expression on the surface of T cells by flow cytometry. Analysis of detergent resistant membrane fraction revealed that IL-2Rα was associated with lipid rafts of T cells. IL-2Rα subunits partly displaced from lipid rafts in DHA-treated T cells compared with controls. Conclusions: Lipid rafts are functional subdomains for IL-2R signaling. DHA enrichment modifies distribution of IL-2Rα in lipid rafts and DHA plays effective immunosuppressive roles probably by partly removing IL-2Rα from lipid rafts.

关 键 词：多不饱和二十二碳六烯酸 白细胞介素-2a受体 抑制作用 细胞膜脂肪微区域 

分 类 号：R392[医药卫生—免疫学]