Exopolysaccharide from Trichoderma pseudokoningii induces macrophage activation

Area of Science:

• Immunology
• Microbiology
• Biochemistry

Background:

• Exopolysaccharides (EPS) are microbial polymers with diverse biological activities.
• Trichoderma species are known for producing bioactive compounds.
• Understanding the immunomodulatory effects of fungal EPS is crucial for developing novel therapeutics.

Purpose of the Study:

• To evaluate the immunomodulatory activity of an exopolysaccharide (EPS) from Trichoderma pseudokoningii.
• To elucidate the molecular mechanisms underlying EPS-mediated macrophage activation.

Main Methods:

• Assessed nitric oxide (NO), tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1β) production in RAW 264.7 cells.
• Investigated phagocytic activity, nuclear factor-kappa B (NF-κB) activation, and mitogen-activated protein kinase (MAPK) signaling.
• Utilized immunofluorescence staining, Western blot analysis, and specific pathway inhibitors.

Main Results:

• EPS significantly increased NO, TNF-α, and IL-1β production and enhanced phagocytosis.
• EPS promoted NF-κB p65 nuclear translocation and induced iNOS expression and IκB-α degradation.
• EPS activated MAPK signaling pathways and cytokine production via Toll-like receptor-4 (TLR4) and Dectin-1.

Conclusions:

• Trichoderma pseudokoningii EPS exhibits potent immunomodulatory effects on macrophages.
• EPS activates macrophages through the NF-κB and MAPK signaling pathways.
• TLR4 and Dectin-1 are critical receptors involved in EPS-induced macrophage activation.