title: Toxoplasma gondii protease inhibitor-1 (TgPI-1) is a novel vaccine candidate against toxoplasmosis.
abstract: 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 IgG(1)/IgG(2a) response, with predominance of IgG(1) production. The cellular immune response was associated with the production of IFN-gamma 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.
authors.affiliation: Laboratorio de Inmunología, Centro de Salud y Medio Ambiente, E.C.y T., Universidad de Gral. San Martín, Provincia de Buenos Aires, Argentina.
authors.forename: Anahi Fernandez
authors.initials: AF
authors.lastname: Cuppari
authors.forename: Vanesa
authors.initials: V
authors.lastname: Sanchez
authors.forename: Bibiana
authors.initials: B
authors.lastname: Ledesma
authors.forename: Fernanda M
authors.initials: FM
authors.lastname: Frank
authors.forename: Alejandra
authors.initials: A
authors.lastname: Goldman
authors.forename: Sergio O
authors.initials: SO
authors.lastname: Angel
authors.forename: Valentina
authors.initials: V
authors.lastname: Martin
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology; D000534:Alum Compounds / Q000494:pharmacology; D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology; D000953:Antigens, Protozoan / Q000235:genetics / Q000276:immunology*; D002478:Cells, Cultured; D004660:Encephalitis / Q000276:immunology / Q000517:prevention & control; D017125:Genes, Protozoan; D007074:Immunoglobulin G / Q000276:immunology; D007371:Interferon-gamma / Q000235:genetics; D016753:Interleukin-10 / Q000276:immunology; D051379:Mice; D008809:Mice, Inbred C3H; D015800:Protozoan Proteins / Q000235:genetics / Q000276:immunology*; D016052:Protozoan Vaccines / Q000276:immunology*; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D014122:Toxoplasma / Q000235:genetics / Q000276:immunology*; D014124:Toxoplasmosis, Animal / Q000276:immunology* / Q000517:prevention & control; D016781:Toxoplasmosis, Cerebral / Q000276:immunology / Q000517:prevention & control
chemical_list: D000276:Adjuvants, Immunologic; D000534:Alum Compounds; D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D007074:Immunoglobulin G; D015800:Protozoan Proteins; D016052:Protozoan Vaccines; D011994:Recombinant Proteins; C412510:TgPI protein, Toxoplasma gondii; D016753:Interleukin-10; C041524:aluminum sulfate; D007371:Interferon-gamma