Colloidal Manganese Salt Improves the Efficacy of Toxoplasma gondii Inactivated Vaccine in Mice.

BACKGROUND/

OBJECTIVES

Toxoplasmosis caused by Toxoplasma gondii still poses a serious threat to public health in most countries and regions. Currently, the lack of effective vaccines necessitates the urgent development of a safe and effective vaccine.

METHODS

In this study, we combined the inactivated T. gondii vaccine with a colloidal manganese salt (Mn jelly [MnJ]) adjuvant.

RESULTS

This triggered a powerful innate immunity, significantly increased the number of CD4+ and CD8+ T cells secreting interferon γ (IFN-γ) in mice, and enhanced the generation of CD8+ central memory T cells and CD8+ effector memory T cells. Compared to the control groups, mice in experimental groups produced more specific IgG, and produced high levels of IL-2, IL-12 and IFN-γ. The survival rate of mice in experimental groups reached 50%, while all control group mice died within 9 days during T. gondii acute infection. Furthermore, the burden of brain cysts in experimental group mice was also significantly reduced by 90.77% compared to the control group during chronic infection.

CONCLUSIONS

These results suggested that the incorporation of an MnJ adjuvant significantly enhances the immunoprotective efficacy of inactivated T. gondii vaccine, positioning this formulation as a promising candidate for development against toxoplasmosis.