Toxoplasma gondii is an intracellular protozoan parasite capable of causing chronic infection by forming persistent cysts in the brain. Despite its global burden, no approved vaccine exists. Virus-like particle vaccines expressing microneme protein 8 (MIC8) or apical membrane antigen 1 (AMA1) of T. gondii have previously shown efficacy. In this study, we generated recombinant vaccinia viruses (rVVs) expressing MIC8 and AMA1 and evaluated their efficacy against T. gondii ME49 infection. BALB/c mice were intramuscularly immunized with a combination of MIC8 and AMA1 rVVs and challenged orally with T. gondii ME49. Immunization with MIC8+AMA1 rVVs produced a significant increase in T. gondii-specific IgG. Splenocyte analysis revealed robust activation of CD4+ and CD8+ T cells, as well as expansion of memory B cells. The immunized group exhibited an 89.6% reduction in brain cyst count, with significantly improved survival compared to the control group. These findings demonstrate that combining the antigens MIC8 and AMA1 using a vaccinia virus platform can effectively promote both humoral and cellular immunity, supporting its potential as a vaccine strategy against T. gondii ME49.
Allyl isothiocyanate (AITC) is a natural product commonly used in food preservation and pharmaceutical applications. Toxoplasmosis, caused by the protozoan pathogen Toxoplasma gondii, is prevalent globally while the impact of AITC on toxoplasmosis is unclear. We explored the effect of AITC on acute toxoplasmosis. We infected C57BL/6 mice with T. gondii type I RH strain following AITC administration. On the 4th day after infection, which corresponds to the initial stage of infection, we collected serum for the determination of inflammatory cytokine levels. The mice serum of the AITC-administered group contained significantly lower levels of granulocyte colony-stimulating factor, interferon-gamma, interleukin (IL)-23 subunit p19, IL-4, IL-6, and monocyte chemoattractant protein-1. The lifespan of the mice in the AITC-administered group was significantly reduced. In vitro experiments showed that AITC promoted the proliferation of intracellular T. gondii accompanied by the inhibition of IL-4, IL-1β, and IL-6 production in RAW264.7 macrophages. Our results showed that AITC facilitated T. gondii infection in the early stage by inhibiting the production of several inflammatory cytokines.