Evaluation of the protection against the formation of cerebral cysts in mice immunized with irradiated tachyzoites of Toxoplasma gondii, using three strains simultaneously

• Grant number: 17/15702-1
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): October 01, 2017
• Effective date (End): September 30, 2018
• Field of knowledge: Biological Sciences - Parasitology - Protozoology of Parasites
• Principal researcher: Andrés Jimenez Galisteo Jr
• Grantee: Thais Santos Melo
• Home Institution: Instituto de Medicina Tropical de São Paulo (IMT). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Toxoplasmosis is an important global protozoa, affecting about one-fifth of the human population, with significant ocular involvement and frequent congenital involvement, with severe sequelae. The disease is acquired by oral ingestion of infectious forms such as cysts and oocysts and the mucous membranes are the first place to combat the agent. Ionizing radiation, a useful tool for the production of vaccines, has been used by us in irradiated tachyzoites, inhibiting its ability to multiply. But, even after the irradiation process, the parasites are shown to induce effective immunity against challenge with the cystogenic strain of Toxoplasma gondii. To date, our results demonstrated that this vaccine model develops effective serum and local protection in the mucosa of immunized mice, which is widely observed by the high levels of protection against the challenge with cystogenic strains, considerably reducing the amount of cysts found in the tissues And even it is not possible to find cysts in some models. All the results obtained by us to date demonstrate that this approach satisfactorily mimics a natural infection, being the most practical form of development of an oral immunogen, making parasite control more effective. In this project we intend to evaluate if there is an increase in the vaccinal efficiency of the mice when we used an association of three different strains of T. gondii when irradiated and used with immunogen. These data are complementary to the main project (FAPESP 2014 / 26782-8) and this would be of great importance for the development of a vaccine directed to animal use in felids, thus breaking the causal network of the disease and significantly reducing environmental contamination, avoiding The direct contamination of the animals of production and at the same time increasing the quality of life of human beings, thus eliminating the transmission of this disease. (AU)