Squalane-based emulsion vaccine delivery system: composition with murabutide activate Th1 response

Area of Science:

• Vaccine delivery systems
• Immunology
• Nanotechnology

Background:

• Emulsions are crucial for subunit vaccine delivery.
• Squalane-based emulsions offer potential as effective delivery vehicles.
• Murabutide (MB) acts as an immune potentiator.

Purpose of the Study:

• To formulate and characterize a novel squalane-based oil-in-water (O/W) emulsion for vaccine delivery.
• To evaluate the emulsion's efficacy in enhancing antigen uptake and immune response.
• To assess the type of immune response (Th1/Th2) elicited by the emulsion.

Main Methods:

• Formulation of squalane-based emulsion with Pluronic F68, Span 85, and Murabutide (MB).
• Characterization of emulsion particle size (134 nm) and zeta potential (-13 mV).
• In vitro cellular uptake studies using fluorescein isothiocyanate (FITC)-labeled ovalbumin (OVA).
• In vivo subcutaneous studies measuring OVA-specific IgG antibody titers and Th1/Th2 cytokines (IL-2, IL-12, IFN-γ).

Main Results:

• Optimized emulsion exhibited a particle size of 134 nm and zeta potential of -13 mV.
• Significant enhancement in cellular uptake of FITC-labeled OVA in the presence of the emulsion.
• Demonstrated a marked upregulation of IL-2, IL-12, and IFN-γ cytokines, indicating a Th1 immune response.
• Elicited both humoral (OVA-specific IgG) and cell-mediated immune responses in mice.

Conclusions:

• The squalane-based O/W emulsion effectively enhances antigen uptake by immune cells.
• The developed delivery system successfully elicits a robust Th1-biased immune response.
• This novel squalane-based emulsion shows significant potential as a vaccine delivery system for future vaccine development.