Evaluation of protection against the formation of cerebral cysts in immunized mice with irradiated tachyzoites of different strains of Toxoplasma gondii

• Grant number: 14/26782-8
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2015
• End date: February 28, 2018
• Field of knowledge: Biological Sciences - Parasitology - Protozoology of Parasites
• Principal Investigator: Andrés Jimenez Galisteo Jr
• Grantee: Andrés Jimenez Galisteo Jr
• Host Institution: Instituto de Medicina Tropical de São Paulo (IMT). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated researchers: Nanci Do Nascimento

Abstract

Toxoplasmosis is an important protozoan infection worldwide, affecting about 1/5 of the human population, with significant ocular involvement and frequent congenital affection. The disease is acquired by oral ingestion of infective forms as cysts and oocysts and mucous the first place to combat agent. Ionizing radiation, a useful tool for the production of vaccines, has been employed by us in irradiated tachyzoites, inhibiting their ability to multiply. But even after the irradiation process, the parasites are shown able to induce effective immunity against challenge with cystogenic strain of Toxoplasma gondii. So far, our results have shown that this vaccine model develops an effective serum and local mucosal protection of immunized mice, which is widely applied by high levels of protection against challenge with cistogênicas strains, considerably decreasing the amount of cysts found in the tissues and even not being able to find cysts in some models. All results obtained by us so far show that this approach mimics the satisfaction of a natural infection, the most practical way of developing an oral immunogen, making the fight against parasites is more effective. In this project we extrapolate this vaccine model and assess whether there is an increase in vaccine efficiency of mice when using a mixture of different strains of T. gondii or even if there is a significant difference in protection between different strains when irradiated and used with immunogen. This would be of great importance for the development of a vaccine directed for animal use in felids, thus breaking the causal network of the disease and significantly reducing the environmental contamination by avoiding direct contamination of livestock and at the same time increasing the quality of life of humans, thus eliminating the transmission of the disease. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

SARTORI, GISELLE PACIFICO; DA COSTA, ANDREA; DOS SANTOS MACARINI, FERNANDA LUCIO; CEOLIN MARIANO, DOUGLAS OSCAR; PIMENTA, DANIEL CARVALHO; SPENCER, PATRICK JACK; DA SILVA NALI, LUIZ HENRIQUE; GALISTEO JR, ANDRES JIMENEZ. Characterization and evaluation of the enzymatic activity of tetanus toxin submitted to cobalt-60 gamma radiation. Journal of Venomous Animals and Toxins including Tropical Diseases, v. 27, APR 30 2021. (14/26782-8)