Protective Effect Against Toxoplasmosis in BALB/c Mice Vaccinated With Toxoplasma gondii Macrophage Migration Inhibitory Factor

Abstract

Toxoplasma gondii is an obligate intracellular parasite responsible for toxoplasmosis, which can cause severe disease in the fetus and immunocompromised individuals. Developing an effective vaccine is crucial to control this disease. Macrophage migration inhibitory factor (MIF) has gained substantial attention as a pivotal upstream cytokine to mediate innate and adaptive immune responses. Homologs of MIF have been discovered in many parasitic species, and one homolog of MIF has been isolated from the parasite Toxoplasma gondii. In this study, the recombinant Toxoplasma gondii MIF (rTgMIF) as a protein vaccine was expressed and evaluated by intramuscular injection in BALB/c mice. We divided the mice into different dose groups of vaccines, and all immunizations with purified rTgMIF protein were performed at 0, 2, and 4 weeks. The protective efficacy of vaccination was analyzed by antibody assays, cytokine measurements and lymphoproliferative assays, respectively. The results obtained indicated that the rTgMIF vaccine elicited strong humoral and cellular immune responses with high levels of IgG antibody and IFN-γ production compared to those of the controls, in addition to slight higher levels of IL-4 production. After vaccination, a stronger lymphoproliferative response was also noted. Additionally, the survival time of mice immunized with rTgMIF was longer than that of the mice in control groups after challenge infection with virulent T. gondii RH tachyzoites. Moreover, the number of brain tissue cysts in vaccinated mice was reduced by 62.26% compared with the control group. These findings demonstrated that recombinant TgMIF protein is a potential candidate for vaccine development against toxoplasmosis.

Protective Effect Against Toxoplasmosis in BALB/c Mice Vaccinated With Recombinant Toxoplasma gondii MIF, CDPK3, and 14-3-3 Protein Cocktail Vaccine

“…Three well-characterized antigens which play key roles in host-parasite interactions, were selected, including TgMIF, TgCDPK3, and Tg14-3-3 (16,19,20,23,44,45). Our study revealed that cocktail protein vaccine is a partial but effective method against acute or chronic toxoplasma infection, compared with vaccines only designed in single or two antigens (15,46). The study indicated that there is an increase in survival time and reduction of brain cysts in immunized mice, as well as enhanced humoral and cellular immune responses compared with the control mice groups or infected mice immunized with any two proteins.…”

“…TgMIF is expressed in both tachyzoite and bradyzoite forms of the parasite ( 14 ). Our previous research revealed that TgMIF is a good vaccine candidate due to its excellent antigenic index and surface probability ( 15 ).…”

Advances in Toxoplasma gondii Vaccines: Current Strategies and Challenges for Vaccine Development

“…Yet, the vaccine still managed to confer partial protection in mice challenged with the ME49 strain via oxidative stress regulation involving iNOS expression [ 60 ]. T. gondii vaccines expressing the macrophage migration inhibitory factor (MIF) significantly protected immunized mice against acute and chronic toxoplasmosis upon a challenge infection with RH tachyzoites and PRU cysts [ 51 ].…”

Role of Host and Parasite MIF Cytokines during Leishmania Infection

“…A similar approach was used in studies in which vaccination with a DNA plasmid encoding Trichinella spiralis MIF or with a T. spiralis MIF fusion protein promoted Th1 responses and partial protection in infected mice [124,125]. Similarly, vaccination with Toxoplasma gondii MIF was shown to promote antibody and T cell responses, improve survival times and reduce brain cyst formation in infected mice [126]. The most impressive impact of vaccination against parasite MIF was shown in a study in which mice were immunized with a Plasmodium berghei MIF-encoding RNA vector prior to infection with blood or liver stage parasites.…”