Cereal β-glucan immune modulating activity depends on the polymer fine structure

Scope: The relationship between the immune modulatory properties of different mixed linkage beta-glucans from plant and microbial origin and their physico-chemical properties is elusive. By the use of murine dendritic cells and multivariate data analysis, this study examines the importance of the physico-chemical characteristics of beta-glucans for their capacity to modulate immune responses. Methods and results: A total of 23 different beta-glucan samples characterised with respect to compositional, molecular, structural and theological properties were investigated for their immune modulatory properties. Most of the beta-glucans showed a decrease in the LPS induced IL-12 production and an increase in the LPS induced IL-10 levels in dendritic cells. When the dendritic cells were stimulated with the probiotic Lactobacillus acidophilus NCFM, the beta-glucans up-regulate the IL-12 production but showed no effect on the IL-10 levels. The modulation of the cytokine responses was shown to depend on the beta-glucan block structure as expressed by the ratio of cellotriosyl to cellotetraosyl units in the molecule as well as the polymer solubility and aggregation in solution. Conclusion: This comparative study reveals that the beta-glucan fine structure and in turn the intermolecular organisation in solution are key factors that determine their immune modulatory capacity. (C) 2014 Elsevier Ltd. All rights reserved.