Mineralization Reduces the Toxicity and Improves Stability and Protective Immune Response Induced by Toxoplasma gondii

Vaccination is an ideal strategy for the control and prevention of toxoplasmosis. However, the thermostability and effectiveness of vaccines limit their application. Here, calcium mineralization was used to fabricate tachyzoites as immunogenic core-shell particles with improved immune response and thermostability. In the current study, RH particles coated with mineralized shells were fabricated by calcium mineralization. The mineralized shells could maintain the tachyzoites structural integrity for at least 12 months and weaken the virulence. Immunization of mice with mineralized tachyzoites induced high levels of antibodies and cytokines. The immunized mice were protected with a 100% survival rate in acute and chronic infection, and brain cyst burdens were significantly reduced. This study reported for the first time the strategy of calcium mineralization on and proved that mineralized tachyzoites could play an immune protective role, thus expanding the application of biomineralization in vaccine delivery.