Dissecting the role and pathogen benefits of trypanothione synthetase overexpression in Trypanosoma cruzi

ARIAS DG; MESIAS AC; GARG NJ; ZAGO MP

Baltimore, Maryland

Congreso; American Society of Tropical Medicine and Hygiene Annual Meeting; 2017

American Society of Tropical Medicine and Hygiene

Chagas disease is a tropical neglected illness caused by Trypanosoma cruzi that remains to be endemic in Latin America. This pathogen has to deal with different oxidant challenges such as the respiratory burst triggered inside the macrophage. Thus, it has an effective antioxidant system capable of overcoming the host barriers and maintaining the redox balance. The parasite antioxidant network utilizes trypanothione (TSH), a low MW dithiol, as substrate. The trypanothione synthetase (TryS) enzyme (produces TSH metabolite) is uniquely present in kinetoplastids, and so it is a good candidate for drug design. In order to characterize its role in the host-parasite interaction, we have overexpressed pTREX encoding TryS in T. cruzi SylvioX10 isolate by electroporation. Recombinant parasites (TryS ) exhibited stable overexpression (>2-fold increase) of the TryS protein and a signifcant increase in TryS enzymatic activity as compared to controls. The TryS showed a higher rate of metacyclogenesis, and ~20% more of infective forms were obtained in TryS cultures compared to the cultures of parasites transfected with empty pTREX. Furthermore, transfectant parasites tolerated higher doses of benznidazole (IC value: 21.3 µM and 11 µM, TryS vs. controls, respectively, p