Nofima, Norwegian Institute of Food, Fishery and Aquaculture Research, PB 210, N-1431 Aas, Norway.
Carbohydr Polym. 2013 Feb 15;92(2):2075-83. doi: 10.1016/j.carbpol.2012.11.092. Epub 2012 Dec 7.
Even if carbohydrate preparations from plant/fungal sources have a high degree of purity, observed immune-stimulation may be caused by minute sample contaminations. Using the example of different β-glucans we present a range of analytical tools crucial for validation of possible immune-stimulatory effects. Two yeast (MacroGard and Zymosan) and one cereal β-glucan (CBG40) increased IL-8 secretion by HT-29 cells considerably. Degradation of the β-glucan samples with β-glucan specific enzymes did hardly influence the effect of Zymosan and CBG40 but significantly decreased the effect of MacroGard. Stimulation of IL-8 secretion by CBG40 and Zymosan was hence not due to their β-glucan content. Instead, the effect of the CBG40 sample was due to low levels of LPS despite the inability of the known LPS inhibitor Polymyxin B to supress its stimulatory effect. We conclude that targeted enzymatic degradation of samples is a powerful validation tool to investigate carbohydrate specific immune-modulation.
即使来自植物/真菌来源的碳水化合物制剂具有高度的纯度，观察到的免疫刺激也可能是由微小的样品污染引起的。我们以不同的β-葡聚糖为例，介绍了一系列对于验证可能的免疫刺激作用至关重要的分析工具。两种酵母（MacroGard 和 Zymosan）和一种谷物β-葡聚糖（CBG40）显著增加了 HT-29 细胞的 IL-8 分泌。用β-葡聚糖特异性酶降解β-葡聚糖样品几乎没有影响 Zymosan 和 CBG40 的作用，但显著降低了 MacroGard 的作用。因此，CBG40 和 Zymosan 刺激 IL-8 分泌并不是由于它们的β-葡聚糖含量。相反，尽管已知的 LPS 抑制剂多粘菌素 B 不能抑制其刺激作用，但 CBG40 样品的作用是由于低水平的 LPS。我们得出结论，有针对性的酶降解样品是一种强大的验证工具，可用于研究碳水化合物的特异性免疫调节。
