Microalgae-Derived Microparticles Improve Immunomodulation via Combined Glycolysis and MAPK Activation

Area of Science:

• Biotechnology
• Immunology
• Materials Science

Background:

• Natural polysaccharides have immunostimulatory potential but suffer from poor solubility, limiting cellular delivery.
• Euglena gracilis microalgae possess abundant intracellular beta-1,3-glucan and a flexible cell membrane suitable for microparticle extraction.

Purpose of the Study:

• To develop a microparticle system from Euglena gracilis (MP_EG) for enhanced beta-glucan solubility and cellular delivery.
• To investigate the cellular uptake mechanisms and immunomodulatory effects of the MP_EG system.

Main Methods:

• Extraction of microparticles (MPs) from Euglena gracilis.
• Enhancement of beta-glucan solubility and loading efficiency using sonication and cell extrusion.
• In vitro assessment of MP_EG cellular uptake pathways (phagocytosis, clathrin-mediated, lipid raft-mediated).
• Analysis of MAPK signaling pathway activation, glycolysis, and cytokine production in macrophages.

Main Results:

• The MP_EG system successfully enhanced beta-glucan solubility and loading efficiency.
• MP_EG demonstrated uptake via multiple endocytic pathways in cells.
• Internalization of MP_EG led to dual activation of MAPK signaling and glycolysis in macrophages.
• Increased production of pro-inflammatory cytokines and lactic acid was observed, indicating strengthened innate immunity.

Conclusions:

• The Euglena gracilis-derived microparticle (MP_EG) system is an effective natural carrier for beta-glucan.
• This system overcomes solubility limitations, facilitating targeted cellular delivery and enhancing innate immune responses.
• MP_EG presents a promising strategy for immunomodulation therapies.