1,25-二羟维生素D3下调Toll样受体7在树突状细胞中的表达

摘要

目的 观察1,25-二羟维生素D3对树突状细胞(DC)的表型、功能以及对其Toll样受体7(TLR7)表达的影响,探讨TLR7在1,25-二羟维生素D3诱导耐受性DC可能的机制.方法 体外扩增小鼠骨髓来源的DC,采用流式细胞术和混合淋巴细胞反应检测1,25-二羟维生素D3对DC表型和功能的影响;利用RT-PCR半定量方法测定1,25-二羟维生素D3对DC的TLR7表达的影响.结果 1,25-二羟维生素D3处理后,DC表达CD86和MHC II的荧光强度均明显降低,差异有统计学意义(P<0.05);对T细胞的刺激能力较对照组明显减弱(P<0.05);与对照组比较,1,25-二羟维生素D3可以明显下调TLR7的表达(P<0.01).结论 1,25-二羟维生素D3可能通过下调TLR7的表达抑制DC细胞的成熟,从而使得DC具有耐受性特征.%Objective To investigate the influence of 1,25-dihydroxyvitamin D3 on dendritic cell( DC ) of pheno-type, function and TLR7 expression, to explore the possible role of TLR7 in the procedure of the inducement of tolerance DC by 1,25-dihydroxyvitamin D3. Methods DC were harvested by differentiating mouse borrow cells in vitro. The influence of 1, 25-dihydroxyvitamin D3 on phenotype and function of DC was determined by flow cytome-try and mixed lymphocyte reactions. The expression of TLR7 on 1,25-dihydroxyvitamin D3-induced DC was determined by semi-quantitative RT-PCR. Results Treated by 1, 25-dihydroxyvitamin D3, DC had significantly lower fluorescence intensity of CD80 and MHC II ( P < 0. 05 ), and DC ability to stimulate T cells was significantly lower than that of the control( P <0. 05 ). Compared to the control, 1,25-dihydroxyvitamin D3 could obviously down-regulate the expression of TLR7( P < 0. 01 ). Conclusion 1, 25-dihydroxyvitamin D3 can inhibit the maturation of DC, and may make DC tolerant by down-regulating the expression of TLR7.