PLGA nanocarriers of total Toxoplasma gondii tachyzoite antigen promote dendritic cell activation

Toxoplasma gondii is an intracellular parasite that causes toxoplasmosis, which can have significant health impacts, particularly in immunocompromised individuals. The total extract from T. gondii contains multiple antigens that are promising vaccine candidates. Thus, the present research aimed to optimise PLGA nanoparticles loaded with total T. gondii tachyzoite antigen through an empirical, stepwise approach. The nanocarriers were designed to target the nasal mucosa and trigger an effective and protective immune response against T. gondii infection. The optimized formulation exhibited favourable physicochemical properties, including an appropriate particle size and low polydispersity, which ensured efficient dendritic cell uptake. Notably, the optimized nanocarriers permeated human nasal epithelial cells, were internalized, and upregulated MHC class II expression in bone marrow-derived dendritic cells. These findings highlight the potential of the formulated PLGA nanoparticles as a promising platform for intranasal vaccines, activating dendritic cells and thus initiating an immune response against T. gondii.