灵芝多糖通过上调STAT4促进人外周血淋巴细胞中Thl细胞的分化

Ganoderma lucidum polysaccharides promote Thl cell differentiation of human peripheral blood lymphocytes through the upregulation of STAT4

目的探讨灵芝多糖（GLP）对外周血淋巴细胞免疫分群的影响及其作用机制。方法取肿瘤患者和正常人的外周血，分离外周血单个核细胞（PBMC）后，用不同剂量的GLP（10ng／ml、50ng／ml和100ng／m1）刺激后，用流式细胞仪检测Dc细胞表面分子（HlA—DR、CD83和CDllc）、Tnll细胞、Th2细胞和NK（CD3-CD56＋）细胞数；并进一步用免疫磁珠分选出正常人外周血CD4’Th细胞后用不同浓度GLP刺激24h后，荧光实时定量Q—PCR检测Thl和Th2细胞因子的表达水平，Westernblot分析Thl分化相关的转录因子水平。结果灵芝多糖可以在体外呈浓度依赖性增加外周血中Thl细胞亚群和DC共刺激分子的表达（P〈0．01），并且增加STAT4的表达和IL-12、IFN-γ和TNF-d的mRNA的表达水平（P〈0．01）。结论灵芝多糖可能通过增加111细胞STAT4的表达水平，促进其向Thl细胞分化，并增加Thl的分泌细胞因子。

Objective To study the effects of Ganoderma lucidum polysaccharide （GLP） on PBMCs and the related immune mechanism. Methods PBMCs from cancer patients and healthy donors were isolated and treated with different doses of Ganoderma lucidum polysaccharides （10 ng/ml, 50 ng/ml and 100 ng/ml）. DC cell costimulatory molecules （HLA-DR, CD83, and CDllc）, Thl （CD3＋ CDS-IFN- γ ） cells, Th2 （ CD3＋ CDS-IL-4＋） cells and NK （CD3-CD56＊） were analyzed by FCM. Furthermore, The CD3＋ CD4＋ Th cells were separated by immunomagnetic beads and stimulated with Ganoderma lucidum polysaccharides at different concentrations in culture. After 24 h, the cytokine expression levels of Thl and Th2 were detected by RT-PCR. The expressions of Thl differentiation-related transcription factor, STAT4, were analyzed by Western blot. Results Ganoderma lucidum polysaccharides can significantly stimulate in vitro Thl cell differentiation （P〈0.01） in a dose depend manner. It correlates with an increased expression of STAT4 and the elevated mRNA expression levels of Thl cytokineincluding IL-12, IFN-~/ and TNF-α （P〈 0.01 ）. Conclusion Ganoderma lucidum polysaccharides may promote Thl differentiation and increase the secretion of Thl cvtokines through the uoregulation of STAT4.