Immunostimulatory activity of polysaccharide-poly(I:C) nanoparticles

Area of Science:

• Immunology
• Nanotechnology
• Biochemistry

Background:

• Mushroom-derived polysaccharides (PS) exhibit immunostimulatory properties.
• Nanoparticle drug delivery systems offer enhanced therapeutic potential.

Purpose of the Study:

• To investigate the immunostimulatory effects of mushroom polysaccharides (PS) alone and complexed with polyinosinic:polycytidylic acid (pIC) in nanoparticle form.
• To evaluate the potential of PS-pIC nanoparticles as an immunization strategy against infectious diseases.

Main Methods:

• Nanoparticle formulation of PS and pIC characterized by atomic force microscopy and dynamic light scattering.
• In vitro assessment of immune cell activation, including Toll-like receptor (TLR) engagement, NFκB signaling, cytokine/chemokine secretion, and nitric oxide production.
• In vivo immunogenicity study in mice using a model antigen (Ovalbumin) with PS-pIC formulation.

Main Results:

• PS-pIC nanoparticles were stable with a size of approximately 200 nm.
• PS activated TLR2, initiating NFκB signaling and Th1-biased immune responses, including nitric oxide production.
• Nanoparticle treatment led to synergistic IL-6 production and increased expression of TNFα, MIP3α, IFNγ, and IP10.
• PS-Ovalbumin-pIC formulation induced superior anti-Ovalbumin IgG responses in mice compared to controls.

Conclusions:

• Co-delivery of pIC via PS nanoparticles activates both TLR2 and TLR3, representing an effective immunization strategy.
• The PS and nucleic acid-based nanoparticle approach, combined with protein antigens, holds promise for preventing infectious diseases.