Rice-derived arabinoxylan fibers are particle size-dependent inducers of trained immunity in a human macrophage-intestinal epithelial cell co-culture model

Bart G J Moerings; Suzanne Abbring; Monic M M Tomassen; Henk A Schols; Renger F Witkamp; Klaske van Norren; Coen Govers; Jeroen van Bergenhenegouwen; Jurriaan J Mes

doi:10.1016/j.crfs.2023.100666

Rice-derived arabinoxylan fibers are particle size-dependent inducers of trained immunity in a human macrophage-intestinal epithelial cell co-culture model

Curr Res Food Sci. 2023 Dec 20:8:100666. doi: 10.1016/j.crfs.2023.100666. eCollection 2024.

Authors

Affiliations

¹ Division of Human Nutrition and Health, Wageningen University & Research, Wageningen, the Netherlands.
² Wageningen Food and Biobased Research, Wageningen University & Research, Wageningen, the Netherlands.
³ Laboratory of Food Chemistry, Wageningen University & Research, Wageningen, the Netherlands.
⁴ Cell Biology and Immunology Group, Wageningen University & Research, Wageningen, the Netherlands.
⁵ Danone Nutricia Research, Utrecht, the Netherlands.

Abstract

Arabinoxylans have been identified for a wide range of purported health-promoting applications, primarily attributed to its immunomodulatory effects. Previously, we have reported the ability of arabinoxylans to induce non-specific memory in innate immune cells, commonly referred to as "trained innate immunity". In the present study, we investigated the effect of particle size on innate immune training and resilience in primary human macrophages as well as in a more physiologically relevant macrophage-intestinal epithelial cell co-culture model. We demonstrated that smaller (>45 & < 90 μm) compared to larger (>90 μm) particle size fractions of rice bran-derived arabinoxylan preparations have a higher enhancing effect on training and resilience in both models. Smaller particle size fractions elevated TNF-α production in primary macrophages and enhanced Dectin-1 receptor activation in reporter cell lines compared to larger particles. Responses were arabinoxylan source specific as only the rice-derived arabinoxylans showed these immune-supportive effects. This particle size-dependent induction of trained immunity was confirmed in the established co-culture model. These findings demonstrate the influence of particle size on the immunomodulatory potential of arabinoxylans, provide further insight into the structure-activity relationship, and offer new opportunities to optimize the immune-enhancing effects of these dietary fibers.

Keywords: Arabinoxylan; Co-culture model; Dectin-1; Particle size; Trained immunity.