Understanding T. cruzi His degradation pathway using synthetic biology

• Grant number: 20/16569-6
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: April 01, 2022
• End date: December 31, 2025
• Field of knowledge: Biological Sciences - Biochemistry - Biochemistry of Microorganisms
• Principal Investigator: Ariel Mariano Silber
• Grantee: Gabriela Torres Montanaro
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 16/06034-2 - The biological role of amino acids and their metabolites in Trypanosoma cruzi, AP.TEM

Abstract

Trypanosoma cruzi is the ethiological agent of Chagas Disease and it is transmitted between mammals by triatomine insects. The fact this parasite transits amongst invertebrate and vertebrate hosts resulted in different enviromental adaptations, characterized by different nutritional conditions. For example, when glucose is limited in the vector's gut, T. cruzi can change its metabolism to degrade amino acids. In this context, histidine (His) is an important metabolite for T. cruzi, not only because it can be found in high concentrations in the triatomine, but also can be utilized by the parasite as an ATP source. Furthermore, His can be completely oxidized to CO2 and it can restore cellular viability after severe nutritional stress. The His degradation pathway has four steps in T. cruzi, but it is not present in Trypanosoma brucei, which makes this trypanosomatid a good model to investigate the biological role of the pathway's presence. In this project, we intend to transfer the complete catabolic His pathway from T. cruzi to T. brucei, both in silico as in vitro, with the goal to evaluate phenotypical characteristics acquired by the second parasite when genetically modified this way. For this, it will be utilized the metabolic map Trypanocyc, where it will be inserted the His degradation pathway. From that, it will be made several simulations to observe if the presence of the pathway interferes in the parasite metabolic flux. Besides, the procyclic form of T. brucei is going to be transfected with the series of plasmids pJG, that allows constitutive and inductive expressions of the four enzymes present in the His degradation pathway of T. cruzi. The transgenic parasites are going to be evaluated phenotypically regarding transport, His metabolization capacity, resistance throw different kind of stresses and vector infection capacity. With the obtained information we can compare with the metabolic model in order to optimize it. Observing the complete His degradation pathway in those parasites, we can determine which evolutionary advantages this brings to the trypanosomatid life cycle and obtain information that can be used in the future. (AU)