ω-3多不饱和脂肪酸对树突状细胞表型和功能的抑制作用

Effect of ω-3 polyunsaturated fatty acids on phenotypes and functions of dendrtic cells

目的研究ω-3多不饱和脂肪酸对树突状细胞的影响。方法采用GM—CSF及白细胞介素(IL)-4诱导人外周单核细胞获得非成熟树突状细胞(DCs),然后以不饱和脂肪酸二十碳五烯酸(EPA),二十二碳六烯酸(DHA)或饱和脂肪酸硬脂酸(SA)处理细胞24 h,并将其分为5组:非成熟DCs组、成熟DCs组、EPA处理组、DHA处理组和SA处理组。内毒素脂多糖(LPS)诱导细胞成熟后用流式细胞仪分别检测DCs表面抗原提呈分子HLA-DR及共刺激分子CD40、CD80、CD86 的表达率;采用酶联免疫吸附试验(ELISA)法检测各组细胞上清中白细胞介素-12及肿瘤坏死因子 (TNF)-α的含量:混合T淋巴细胞反应检测DCs刺激细胞增殖能力。结果非成熟DCs组CD80、 CD86及HLA-DR的表达率为(48．7±17．5)％、(57．3±16．9)％及(78．5±15．1)％,成熟DCs组这 3种分子高表达,其表达率为分别为(86．3±10．8)％、(77．4±13．5)％及(79．6±14．5)％,EPA及 DHA处理组CD80、CD86及HLA-DR的表达率分别为(65．5±17．2)％、(60．2±9．1)％、(56．9± 12．3)％和(64.7±13．5)％、(57．7±13．6)％、(64．9±5．8)％,与成熟DCs组相比有统计学意义 (P<0．05),而SA处理的DCs表达率分别为(88．1±4．5)％、(71．2±14．5)％、(75．9±10．7)％与成熟组相比差异无统计学意义(P>0．05)。细胞上清IL—12及TNF-α的含量,5个组分别为(70．8± 1．9)、(286．8±80．4)、(158．5±43．5)、(161．0±20．1)、(271．5±45．6)和(4．7±2．3)、(32．1± 12．5)、(13．7±4．8)、(9．0±6．5)、(27．6±11．4)ng／L,EPA及DHA处理组与成熟DCs组相比差异有统计学意义(P<0．01),而SA组与成熟DCs组相比差异无统计学意义(P>0．05)。EPA及DHA 组其DCs刺激T细胞增殖的能力亦显著下降(P<0．05),并且随着EPA及DHA浓度的增加,其下降越明显。结论ω-3多不饱和脂肪酸可以在体外抑制树突状细胞免疫表型的表达及细胞因子的释放,降低其刺激T细胞增殖的能力。

Objective To investigate the effect of ω- polyunsaturated fatty acids on phenotypes and functions of dendrtic cells. Methods Dendritic cells were generated from human peripheral blood monocytes in the presence of GM-CSF and IL-4, and then treated with EPA, DHA or SA for 24 h, Lipopolysaccharide was used for maturation of dendritic cells. The expression of CD40, CD80, CD86 and HLA-DR was detected by flow cytometer; The concentrations of cytokines IL-12 and TNF-α were determined by enzyme-linked immunoadsordent assay. The proliferation ability of allogeneic T cells stimulated by dendritic cells was evaluated by 3H-TdR, Results Mature DCs expressed high level of costimulatory molecules and HLA-DR, The expression rate of CD80, CD86 and HLA-DR in mature DCs group was （86,3 ± 10,8） %, （77,4 ± 13.5） %, （79,6 ± 14.5） % respectively; The expression rate of CDS0, CD86 and HLA-DR in EPA group and DHA group was （65,5 ± 17.2） %, （60.2 ± 9, 1） %, （56,9 ± 12.3） % and （64.7 ± 13.5） %, （57. 7 ± 13.6） %, （64,9 ± 5.8） %, and decreased obviously as compared with mature DCs group （ P〈0,05）. The expression rate of CD80, CD86 and HLA- DR in SA-treated DCs group was （88.1 ±4.5）%, （71,2± 14.5）% and （75.9 ± 10.7） respectively, and had no difference with that in mature DCs group. The levels of IL-12 and TNF-α in 5 different DCs groups were （70.8 ± 1.9）, （286.8±80.4）, （158.5± 43.5）, （161.0± 20.1）, （271.5± 45.6） and （4.7± 2.3）, （32.1± 12.5）, （13.7±4.8）, （9.0±6.5）, （27.6± 11.4） ng/L respectively. The levels of IL-12 and TNF-α in EPA- and DHA-treated DCs group were decreased significantly as compared with those in mature DCs group （P 〈 0.01）. EPA and DHA reduced the proliferation ability of allogeneic T cells stimulated by DCs significantly （P 〈 0.05）. Conclusion ω- polyunsaturated fatty acids can reduce the expression levels of ccstimulatory molecules and the productions of IL-12 and TNFα of dendritic cells, correspondingly restrain the proliferation ability of T cells stimulated by dendritic cells.