Toxoplasma gondii Protease inhibitor-1 (TgPI-1) is a novel vaccine candidate against toxoplasmosis

FERNANDEZ CUPPARI A; SANCHEZ V; LEDESMA B; FRANK FM; GOLDMAN A; ANGEL SO; MARTIN V

VACCINE

Elsevier

Año: 2008 vol. 1 p. 1 - 1

0264-410X

The Toxoplasma gondii serin protease inhibitor-1 (TgPI-1) is a dense granule antigen that showed to specifically inhibit trypsin, chymotrypsin and neutrophil elastase, suggesting a possible modulatory role during the parasite invasion process and on the development of the innate immune response. To study the immune-protective value of TgPI-1, C3H/HeN mice were immunized with a recombinant form of the antigen rTgPI-1 combined with alum. All immunized mice produced specific anti-rTgPI-1 immunoglobulins, with high IgG antibody titers and a mixed IgG1/IgG2a response, with predominance of IgG1 production. The cellular immune response was associated with the production of IFN-ã and IL-10 cytokines. Vaccinated mice displayed significant protection against an oral challenge either after a lethal infection with Me49 cysts (90% survival vs. 50%) and also after a non-lethal infection (58% reduction in brain parasite load) compared to the non-vaccinated control group. In conclusion, rTgPI-1 elicits a strong specific immune response providing partial protection against both T. gondii acute and chronic infection, so it would be a good candidate in a vaccine against toxoplasmosis, which could be combined with other relevant parasite antigens.