To better study T. vivax infections in well-established experimental models, the state-of-the-art in vitro, in vivo and ex vivo imaging tools that were available was revisited by our group and adapted to trypanosomatids generating new and more powerful essential tools for imaging systems (Goyard et al., 2013; Rouault et al., 2016; Dias de Melo et al., 2017). These efforts allow us today to quantify in real time the particularities, abundance and magnitude of trypanosomal infections, to reveal original data related to the development of the pathology, thus opening new research and innovation opportunities. Our preliminary results described the development of a reference model for T. vivax, especially due to the high virulence of the mouse and the parasite's difficulty to grow in axenic cultures. However, to study animal trypanosomosis, Nagana, and to characterize some of the major actors in T. vivax immunopathology, our laboratory has developed the complex T. vivax axenic cultures of an African strain and today dominates the process of parasitic differentiation in in vitro infectious forms (D'Archivio et al., 2011). Reproducible infections were obtained in mice of several strains, which presented parasitological, histological and pathological parameters very similar to those observed in the field, characteristic of cattle trypanosomosis - severe acute anemia, thrombocytopenia and a significant reduction of B lymphocytes after infection (Chamond et al. (2010; Blom-Potar et al., 2010). The in vitro cultivated T. vivax stages allowed the laboratory to construct the first specific expression vectors, which led us to develop reverse genetics for this parasite (D'Archivio et al., 2011).Thus, mastery of axenic cultures was useful for establishing and optimizing parasite transfections and selecting stable mutants that continue metacyclogenesis while maintaining virulence for immunocompetent mice. The region containing the T. vivax ribosomal promoter was inserted into the plasmid to improve expression of the luciferase reporter gene transgene and to allow integration of the vector into the genome. With these tools, the group analyzed the evolution of the infectious process and the distribution of parasites in mouse tissues. The results corroborated the use of real-time biophotonic analysis to study and monitor the infectious process in vivo. Through these experiments, we could suggest that the blood-brain barrier (BBB) is crossed by trypanosomes in the later stages of infection (D'Archivio et al. 2013). T. vivax, in fact, penetrate the brain parenchyma shortly before the death of the animals. Goals: To design the T.vivax brain impairment process and the functional / lethal consequences of the infection process, especially the main histopathological lesions of the brain, forming a base of studies focused on neuroinflammation and the breakdown of the blood-brain barrier. The project will serve as the basis for interfacing with other subprojects of a thematic study involving infections with infectious Zika virus clones, modified by reporter genes for analysis of the infectious process in vitro and in vivo by 2D and 3D imaging.
News published in Agência FAPESP Newsletter about the scholarship: