Melatononin modulation of immune response to Toxoplasma gondii infection

• Grant number: 18/03888-6
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): June 01, 2018
• Effective date (End): November 30, 2018
• Field of knowledge: Biological Sciences - Immunology
• Principal researcher: Cristina Ribeiro de Barros Cardoso
• Grantee: Cássia Aparecida Sebastião
• Home Institution: Faculdade de Ciências Farmacêuticas de Ribeirão Preto (FCFRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Toxoplasma gondii (T.gondii), a coccidian member of the Apicomplexa phylum infects approximately one-third of the world's human population. In endemic regions, especially Brazil, about 50 to 80% of the population has been exposed to T. gondii infection at least once, and cases of multiple exposures to different strains are common. The identification of molecules with therapeutic potential and the understanding of their actions in the mechanisms of modulation of the immune response, has contributed in an important way in the development of new therapies for infectious diseases. Previous studies have demonstrated the actions of the hormone melatonin on both, host immunity and replicative cycle of several pathogens, which potentiates their control. In this sense, we aim to study the influence of melatonin treatment on the modulation of T.gondii infection. For this, C57BL/6 mice will be infected with T.gondii cystogenic strain (ME49) and treated with melatonin to verify their therapeutic potential in resolution of the disease. The clinical signs and the immunological functionality of the animals will be evaluated effectively. For this, we will analyze the cellular infiltrate, tissue lesions, production of pro and anti-inflammatory cytokines, as well as the tissue regulatory response. Finally, it is expected, with this project, to attest the impact of melatonin on the immune competence of the host to the challenge with T.gondii.