Andrade Neto, Valter Ferreira deBrito, Ramayana Morais de Medeiros2019-08-142019-08-142019-04-25BRITO, Ramayana Morais de Medeiros. Avaliação dos efeitos da infecção por toxoplasma gondii na estrutura do tecido cerebral e influência sobre a resposta neuroimunopatogênica. 2019. 89f. Dissertação (Mestrado em Biologia Parasitária) - Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, 2019.https://repositorio.ufrn.br/jspui/handle/123456789/27510Toxoplasma gondii is able to manipulate the host's immune system to establish a persistent and efficient infection, contributing to the development of brain abnormalities with behavioural repercussions. In this context, the aim of this work was to evaluate the effects of T. gondii infection on the structure of brain tissue and its influence on the neuroimmunopathogenic response. C57BL/6 and Balb/c mice were infected with T. gondii ME49 strain tissue cysts and accompanied during 30 days. After this period, levels of antibody IgG anti-T. gondii and cytokines IFN-γ, IL-12, TNF-α, IL-10 e TGF-β were measured. After blood withdraw, mice were perfused and the brains submitted to immunohistochemistry for perineuronal nets and cyst quantification. Our results showed that C57BL/6 mice were more susceptible to infection than Balb/c animals, showing 40% and 100% survival, respectively. Increased body weight loss was also observed among infected C57BL/6 susceptible mice. Analysis of anti-T gondii IgG production demonstrated that C57BL/6 animals produce lower antibody levels than Balb/c mice. C57BL/6 mice showed high serum TNF-α and IL-12 production as well as TGF-β and IL-10 levels were similar between the two strains; C57BL/6 also had a higher number of cerebral cysts, with a higher occurrence of cysts in the caudal region of the brain when compared to Balb/c mice, which presented a more homogeneous cysts distribution. Immunohistochemistry analysis revealed greater loss of labeling for perineuronal networks in C57BL/6 animals when compared to Balb/c animals. These data raise a discussion about the ability of T. gondii influence the brain functioning and may be related to the development of neurological symptoms similar to those observed in well-known neuroinflammatory and neurodegenerative diseases. Our results indicate that C57BL/6 animals are more susceptible to infection due to high production of inflammatory cytokines (TNF-α and IL-12) and low production of regulatory cytokine (TGF-β). This data may be related to the different distribution pattern of cysts between the mice lineages, with C57BL/6 showing a significantly higher number besides showing a greater perineuronal networks impairment when compared to Balb/c.Acesso AbertoToxoplasma gondiiNeuroxoplasmoseInflamaçãomasterThesisCNPQ::CIENCIAS BIOLOGICAS