二十碳五烯酸影响T细胞膜脂肪微区域中IL-2受体的分布  

EICOSAPENTAENOIC ACID ALTERS INTERLEUKIN-2 RECEPTOR DISTRIBUTION IN DETERGENT-INSOLUBLE MEMBRANE DOMAIN

作　　者：李秋荣[1] 马健[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：《营养学报》2005年第6期455-459,共5页Acta Nutrimenta Sinica

基　　金：国家重点基础研究发展规划项目(No.2003CB515502);南京军区总医院科研基金(No.2004034)

摘　　要：目的:研究二十碳五烯酸(EPA)对T细胞膜脂肪微区域(lipidrafts)中IL-2受体(IL-2R)分布的影响。方法:EPA(20︰5)处理JurkatE6-1T细胞为实验组,硬脂酸(18:0)处理为阴性对照。用流式细胞仪检测对T细胞表面分子CD25(IL-2α受体)表达的抑制作用。应用蛋白免疫印迹分析,化学发光法检测IL-2α受体所在的T细胞膜脂肪微区域分离组分。结果:用硬脂酸处理T细胞,细胞表面CD25阳性表达细胞为39.53%,不同浓度的EPA(5、12.5、25,50、75μmol/L)处理,CD25阳性表达细胞分别为36.12%、31.30%、23.59%、16.67%和11.65%,EPA可抑制T细胞表面分子CD25的表达。蛋白印迹分析确定IL-2α、IL-2Rβ和IL-2Rγc都存在于微区域组分中,EPA处理使部分IL-2Rα、IL-2Rβ和IL-2Rγc从膜脂肪微区域移位到可溶膜区域。结论:膜脂肪微区域为IL-2受体信号传导的功能性亚区域,EPA通过调节IL-2Rα、IL-2Rβ和IL-2Rγc在膜脂肪微区域的分布,使部分IL-2R从功能性脂肪微区域移位到非功能性可溶膜区域,而产生免疫抑制作用。Objective： To determine whether EPA altering distribution of IL-2R in membrane subdomains. exert effectively immunosuppressive function by Method： The human Jurkat E6-1 T cells were cultured in EPA-supplemented medium and the cells treated with stearic acid served as control. The effect of EPA on CD25 （IL-2α receptor） expression on the surface of T cells was investigated by flow cytometry. The lipid rafts were isolated by discontinuous sucrose density gradient ultracentrifugation. The localization of IL-2Rα, IL-2Rβ, and IL-2Rγc in fractions isolated and the effect of EPA treatment were determined by immunoblot and chemiluminescence. Results： EPA suppressed CD25 expression on the surface of T cells. IL-2Rα, IL-2Rβ, and IL-2Rγc were associated with lipid rafts of T cells, and these subunits were partly displaced from lipid rafts of EPA-treated T cells. Conclusion： Lipid rafts are functional subdomains for IL-2R signaling. EPA enrichment modifies distribution of IL-2Rα, IL-2Rβ, and IL-2Rγc in lipid rafts and EPA plays immunosuppressive roles probably by partly removing IL-2R from lipid rafts.

关 键 词：二十碳五烯酸 细胞膜脂肪微区域 白细胞介素-2受体 

分 类 号：R151[医药卫生—营养与食品卫生学]