Evaluation of protective effect of pVAX-TgMIC13 plasmid against acute and chronic Toxoplasma gondii infection in a murine model

• A DNA vaccine expressing T. gondii mic13 was constructed and evaluated in Kunming mice.
• pVAX-TgMIC13 induced significant lymphoproliferation, cytokine production and antibody responses.
• Immunized mice showed increased survival time (21.3 days) and 57.14% reduction of brain cysts.
• T. gondii MIC13 is a potential candidate to be included in future vaccines against acute and chronic T. gondii infection.

Toxoplasma gondii is a significant zoonotic parasite which can cause congenital infection and abortion in warm-blooded animals and humans. Microneme protein 13 (MIC13) plays an important role in attachment and penetration of the host cell by T. gondii. In this study, a DNA vaccine expressing mic13 of T. gondii was constructed and its protective efficacy was evaluated in Kunming L615H2k mice. Immunization with pVAX-TgMIC13 induced a strong immune responses demonstrated by significant lymphocyte proliferation, cytokine production and antibody responses. Immunized mice showed increased survival time (21.3 ± 11.3 days) and reduced number of cysts in brain of mice (57.14%) after challenge with tachyzoites of the virulent T. gondii RH strain and cysts of the T. gondii PRU strain, respectively, demonstrating that T. gondii MIC13 is a potential vaccine candidate, worth being included in future vaccine development against acute and chronic T. gondii infection.