Genômica evolutiva e o estudo de mecanismos de adaptação do metabolismo de Leishmania ao parasitismo intracelular

Abstract

The current treatment recommended for visceral and cutaneous leishmaniasis is based on a limited number of drugs, presents variable efficiency, many adverse effects and parenteral formulation and thus has to be administrated by physicians, which increases the cost of the treatment. Therefore, the identification of novel therapeutic targets is a priority strategy for disease control. In this project, we used different genomic approaches such as comparative genomics, metabolic networkreconstruction for the identification of potential virulence factors that could be used as therapeutic targets for the treatment of leishmaniasis. Comparative genomic analysis between seventeen trypanosomatid genomes belonging to four different genus revealed adaptive mechanisms related to cell invasion and evasion of the immunesystem. These studies revealed that the genome of L. tarentolae, a species not infective to mammals, lost important genes associated with infectivity. These genes are associated with different metabolic pathways, among them the glycan biosynthesis. Flow cytometric analysis corroborated these in silico findings. In a second part, metabolic models were used to integrate data from quantitative proteomics and metabolomics by 1H-NMR to identify the most important enzymesthat impact the metabolic flow during the in vitro amastigogenesis process. Visceral species, L. donovani and L. infantum, showed greater change of metabolic fluxes than L. major that causes cutaneous leishmanasis. L. tarentolae, which is apathogenic to mammalian species, presented the lowest rate of change of metabolite concentrationover amastigogenesis process. Homoserine kinase and trypanothione synthase were the most important enzymes for generating a metabolic profile associated with infective capacity and were considered good candidates to be tested as therapeutic targets against leishmaniasis.