Oat-Derived β-Glucans Induced Trained Immunity Through Metabolic Reprogramming.

Area of Science:

• Immunology
• Metabolic reprogramming
• Innate immunity

Background:

• Trained immunity involves epigenetic and metabolic changes in innate immune cells for enhanced defense against secondary infections.
• While fungal (1,3)/(1,6)-β-glucan is known to induce trained immunity, the impact of oat-derived (1,3)/(1,4)-β-glucan remains unexplored.

Purpose of the Study:

• To investigate the potential of oat β-glucan to induce trained immunity.
• To explore the underlying metabolic reprogramming mechanisms involved in oat β-glucan-induced trained immunity.

Main Methods:

• Validated cell culture models using mouse monocytes/macrophages and human THP-1 cells.
• Stimulated cells with oat β-glucan and assessed immune responses upon re-stimulation with Toll-like receptor (TLR) ligands.
• Analyzed changes in mRNA expression of inflammatory cytokines and key metabolic enzymes.

Main Results:

• Oat β-glucan priming significantly increased mRNA expression and production of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) after TLR stimulation.
• Upregulation of key enzymes in the glycolytic and tricarboxylic acid pathways was observed.
• Inhibition of these metabolic enzymes reduced the enhanced TNF-α and IL-6 production.

Conclusions:

• Oat β-glucan effectively induces trained immunity in innate immune cells.
• This induction is mediated by metabolic reprogramming, specifically involving the upregulation of glycolytic and TCA cycle enzymes.
• Dietary fiber, like oat β-glucan, may play a crucial role in maintaining long-term innate immune system function, offering potential benefits for disease prevention.