DescriptionArabinoxylans of various structures and sources have shown the ability to induce a range of immune responses in different cell types in vitro and in vivo. Although the mechanism by which arabinoxylans enhance the immune system remains to be determined, it is reasonable to speculate that they trigger immune cells through pattern recognition receptor (PRR) ligation. This study aimed to investigate arabinoxylan preparations from various sources for their induction of innate immune priming and resilience. Additionally, we investigated the effect of particle size on the innate immune priming and resilience activity. Human monocytes were stimulated with different arabinoxylan preparations, using the training protocol as previously published, with or without a Dectin-1 antagonist or CR3 antibody. Furthermore, human monocytes were stimulated with different particle size fractions to assess the effect of particle size. Also, the impact of oral administration of rice-bran-1 on the immune response was investigated in a mouse-model. Exposure of human monocytes to rice and wheat-derived arabinoxylan preparations induces immune priming and resilience through increased TNF-α and IL-6 secretion, which was mainly dependent on interaction with Dectin-1b. Rice bran-derived arabinoxylan preparations with a smaller particle size fraction were able to enhance priming and resilience effects in human macrophages. In addition, oral exposure of mice to 1% w/w rice bran-1 enhanced TNFα and IL-6 production upon ex vivo stimulation of bone marrow cells and whole blood. We have shown that arabinoxylan preparations can induce innate immune priming and resilience in human macrophages in vitro. Stronger effects were observed using a smaller particle size fraction. In addition, we prove immune priming effects in mouse bone marrow and whole blood compartments after oral exposure. These results extend current knowledge on dietary fiber-induced trained innate immunity and indicates the therapeutic potential of arabinoxylans as immune stimulating agents.
|29 May 2023 → 31 May 2023
|5th International Symposium on Trained Immunity