二十二碳六烯酸对人外周血树突状细胞成熟的影响

Effect of Docosahexaenoic acid on maturation and immunologic function of human peripheral blood Dendritic cells

目的探讨二十二碳六烯酸(DHA)在体外对人外周血来源树突状细胞(DCs)成熟状态及免疫学功能的影响。方法经淋巴细胞分离液(Ficoll)密度梯度离心法分离出单个核细胞,用含rhGM-CSF和rhIL-4培养液诱导5d,获得未成熟DCs,并分为4组:未成熟组、成熟组、DHA组和饱和脂肪酸(SA)组。经DHA孵育24h,内毒素脂多糖(LPS)作用48h,于第8天,Wright-Giemsa染色观察各组DCs形态;流式细胞仪检测表型,逆转录-聚合酶链反应(RT-PCR)检测DCs共刺激分子CD80、CD86及HLA-DR mRNA的表达;ELISA检测各组细胞上清液中IL-12及TNF-α的含量。结果 DHA组细胞上清液IL-12和TNF-α的含量比成熟组低(P<0.01),而SA组与成熟组比较差异无统计学意义(P>0.05)。DHA干预下平均荧光强度呈明显下调。成熟组CD80、CD86及HLA-DR mRNA相对表达量比未成熟组高(P<0.01);DHA组比成熟组低(P<0.01);而SA组与成熟组相比无差异(P>0.05)。结论 DHA可下调DCs共刺激分子CD80、CD86及HLA-DR的表达,降低IL-12及TNF-α的释放,减弱DCs的抗原提呈能力,且可抑制DCs体外成熟。

Objective To investigate the effect of Docosahexaenoic acid（DHA） on maturation and immunologic function of human peripheral blood Dendritic cells（DCs） in vitro.Methods Peripheral blood mononuclear cells（PBMC） were separated by Ficoll,and were induced by rhGM-CSF and rhIL-4,and then obtain immature DCs for five days,divided into 4 groups：immature DCs group,mature DCs group,DHA treatment group and the SA treatment group.After incubated 24 h by DHA and then induced 48 h by lipopolysaccharide（LPS）,observed DCs patterns in each group by stained with Wright-Giemsa,properties of DCs detected by FCM detection expression of DCs costimulatory molecules CD80,CD86 mRNA and surface antigen-presenting molecules human leukocyte antigen-DR（HLA-DR） mRNA by RT-PCR,and detected IL-12 and TNF-α levels of cell supernatant by ELISA.Results The relative expression of mRNA in CD80,CD86 and HLA-DR,it is higher in mature DCs group than immature DCs group,the difference was significant（P〈0.01）,it is lower in DHA treatment group than mature DCs group,the difference was significant（P〈0.01）.The differences in SA treatment group compared with the mature wasnot significant（P〈0.05）.Average fluorescent intensity was significantly lower in DHA intervention.Content on the supernatant of IL-12 and TNF-α,it was lower in DHA treatment group than mature DCs group,the difference was significant（P〈0.01）.The differences in SA treatment group compared with the mature wasnot significant（P〈0.05）.Conclusion DHA can reduce dendritic cell costimulatory molecules CD80,CD86 and surface antigen-presenting molecule HLA-DR expression in vitro,reduce cytokine Interleukin-12 and tumor necrosis factor-α release,decrease dendritic cells capability in antigen presentation,inhibit the maturation of dendritic cells in vitro.