新疆两个产地玛咖水提物对树突状细胞成熟和功能的影响

Effects of water extracts of Lepidium meyenii walp （maca） growing in two different places in Xin-jiang on the maturation and function of dendritic cells

目的本研究主要探讨新疆两个产地玛咖水提物（Lepidium meyenii walp water extract，LMWE）对树突状细胞（dendritic cell，DC）的成熟及功能的影响，评价其对免疫系统的调节作用。方法制备来自塔什库尔干县（塔县，Ta xian）和阿拉沟（A La gou）玛咖的水提物，分别命名为LMWE-T和LMWE-A。用不同浓度LMWE-T/A（按照多糖浓度）处理C57BL/6小鼠骨髓来源的DC及脾脏细胞，流式细胞术检测DC的凋亡、DC比例、共刺激分子表达，ELISA检测细胞因子的分泌水平，MTT法检测脾脏细胞增殖，混合淋巴细胞反应检测LMWE对DC功能的影响。结果两种LMWE对DC的凋亡和比例均没有影响，显著增加了DC表面CD40、CD86的表达和TNF-α、IL-12p40、IFN-γ的分泌水平，同时显著增强了DC的功能，并且促进了脾脏细胞的增殖。LMWE-T与LMWE-A相比，LMWE-A对表面分子CD86的表达、IFN-γ的分泌以及脾脏细胞的增殖能力均显著高于LMWE-T的刺激作用。Toll样受体4（Toll-like receptor 4，TLR4）抑制剂TAK-242预处理显著抑制了两种LMWE对CD40表达及TNF-α、IL-12p40分泌的促进作用。结论本实验研究结果表明，LMWE对DC没有毒副作用，通过TLR4信号通路刺激DC成熟，增强DC的功能，同时也具有刺激脾脏细胞增殖的能力，说明LMWE具有潜在的免疫促进作用。LMWE-A的免疫增强作用略高于LMWE-T。

ObjectiveTo investigate the effects of water extracts of Lepidium meyenii walp （LMWE） collected from two different places in Xinjiang on the maturation and function of dendritic cells （DCs） and to evaluate their roles in immunoregulation.MethodsWater extracts of LMWE growing in Tashikuergan County （Ta xian） and A La gou of Xinjiang were prepared and named as LMWE-T and LMWE-A, respectively. Bone marrow-derived DCs and splenocytes isolated from C57BL/6 mice were treated with different concentrations of polysaccharide extracts from LMWE-T/A. Effects of LMWE-T/A on the percentage and apoptosis of DC, expression of co-stimulatory molecules and secretion of cytokines were detected by flow cytometry and ELISA. MTT assay was used to analyze the proliferation of splenocytes. Changes in the functions of DC were evaluated by mixed lymphocyte reaction （MLR）.ResultsLMWE-T/A had no influence on the percentage and viability of DC. Expression of CD40 and CD86, and secretion of TNF-α, IL-12p40 and IFN-γ were significantly increased by LMWE-T/A treatment in a dose-dependent manner. LMWE-T/A treatment enhanced the functions of DCs and also dose-dependently promoted the proliferation of splenocytes. LMWE-A was more effective than LMWE-T in promoting CD86 expression, IFN-γ secretion and splenocyte proliferation. Pretreatment with TAK-242, an inhibitor of Toll-like receptor 4 （TLR4）, could significantly inhibit the regulatory effects of LMWE-T/A on CD40 expression and the secretion of TNF-α and IL-12p40.ConclusionThis study shows that LMWE could promote the maturation of DC through TLR4 signaling pathway, enhance the functions of DC without side effects on DC survival, and increase the proliferation of splenocytes, indicating that LMWE has a potential immunopotentiating effect. LMWE-A has better effects than LMWE-T on immune enhancement.