Department of Human Biology, School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands.
PLoS One. 2012;7(10):e46895. doi: 10.1371/journal.pone.0046895. Epub 2012 Oct 16.
In vitro and animal studies have suggested that plant sterols and stanols increase cytokine production by T-helper-1 cells. This may be beneficial for patient groups characterized by a T-helper-2 dominant immune response, e.g. asthma patients. (1) to evaluate whether sitostanol induces a T-helper-1 shift in peripheral blood mononuclear cells (PBMCs) from asthma patients, and (2) to unravel the role of regulatory T-cells in this respect.
METHODOLOGY/PRINCIPAL FINDINGS: PBMCs from 10 asthma patients and 10 healthy subjects were isolated and incubated with 1.2 µM sitostanol, while stimulated with 5 µg/ml PHA. Similar amounts of cholesterol were used to determine whether effects were specific for plant stanols or for sterols in general. Changes in cytokine production were measured using antibody arrays and ELISAs. Changes in regulatory T-cell population size were measured by flow cytometry, using intracellular Foxp3 staining. Sitostanol increased production of IFNγ by 6.5% and IL-2 by 6.0% compared to cholesterol (p<0.01). No changes in IL-4 and IL-13 were found. Interestingly, this effect was only present in PBMCs from asthma patients. The number of Foxp3+ cells tended to increase and their activity, measured by IL-10 production, increased after sitostanol treatment in PBMCs from asthma patients compared to controls by 32.3% (p = 0.077) and 13.3% (p<0.05), respectively.
CONCLUSIONS/SIGNIFICANCE: Altogether, the sitostanol-induced Thelper-1 shift in PBMCs from asthma patients and the stimulating effects of sitostanol on Treg cell numbers and activity indicate a possible novel approach for plant stanol ester enriched functional foods in the amelioration of asthmatic symptoms. Functional effects, however, require further evaluation.
体外和动物研究表明，植物甾醇和甾烷醇可增加 T 辅助-1 细胞的细胞因子产生。这对于以 T 辅助-2 优势免疫反应为特征的患者群体可能是有益的，例如哮喘患者。（1）评估植物甾烷醇是否会诱导哮喘患者外周血单个核细胞（PBMC）中的 T 辅助-1 偏移，以及（2）阐明调节性 T 细胞在这方面的作用。
方法/主要发现：从 10 名哮喘患者和 10 名健康受试者中分离 PBMC，并在 5μg/ml PHA 刺激下用 1.2μM 植物甾烷醇孵育。使用相同量的胆固醇来确定这些作用是否是植物甾烷醇特有的，还是固醇类物质的一般作用。使用抗体阵列和 ELISA 测量细胞因子产生的变化。通过流式细胞术使用细胞内 Foxp3 染色来测量调节性 T 细胞群体大小的变化。与胆固醇相比，植物甾烷醇使 IFNγ 增加了 6.5%，IL-2 增加了 6.0%（p<0.01）。未发现 IL-4 和 IL-13 的变化。有趣的是，这种作用仅存在于哮喘患者的 PBMC 中。与对照组相比，哮喘患者 PBMC 中 Foxp3+细胞的数量在植物甾烷醇处理后趋于增加，其活性通过 IL-10 产生增加了 32.3%（p=0.077）和 13.3%（p<0.05）。
结论/意义：总之，哮喘患者 PBMC 中植物甾烷醇诱导的 Th1 偏移以及植物甾烷醇对 Treg 细胞数量和活性的刺激作用表明，富含植物甾烷醇酯的功能性食品可能成为改善哮喘症状的新方法。然而，功能作用需要进一步评估。
