Enzymatic characterization of tryparedoxin cytoplasmic peroxidase of Leishmania (L.) amazonensis and effect of overexpression in resistance to oxidative stress and protein expression of the parasite

• Grant number: 14/16399-2
• Support type: Scholarships abroad - Research Internship - Master's degree
• Effective date (Start): November 01, 2014
• Effective date (End): January 31, 2015
• Field of knowledge: Biological Sciences - Parasitology - Protozoology of Parasites
• Principal researcher: Beatriz Simonsen Stolf
• Grantee: Karoline Mathias Leite
• Supervisor abroad: Carlos Alberto Robello Porto
• Home Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Research place: Institut Pasteur de Montevideo, Uruguay
• Associated to the scholarship: 13/13527-7 - Analysis of the participation of oligopeptidase B and cytoplasmic tryparedoxin peroxidase in virulence of Leishmania (Leishmania) amazonensis, BP.MS

Abstract

Leishmania ssp. are protozoan parasites responsible for a complex of diseases known as leishmaniasis. Present two main developmental forms: a flagellated promastigotes in the alimentary tract of the insect vector, and the amastigote no external flagellum, within cells of the mononuclear phagocytic system, preferably macrophages of the vertebrate host. The ability for survival and multiplication in specialized cells in the destruction of pathogens due to the ability of the parasite to evade the microbicidal property of these cells for the production of molecules called virulence factors. A protein previously described as virulence factors in trypanosomatids is tryparedoxin cytoplasmic peroxidase (cTXNPx), antioxidant protein that participates in the detoxification of hydroperoxides. In fact, promastigotes of L. (L.) donovani and T. cruzi trypomastigotes superexpressoras of cTXNPx showed higher intracellular survival in macrophages. The importance of cTXNPx as virulence factor was reinforced by comparing the proteomes of two strains of L. (L.) infantum with different virulence, we identified increased expression of cTXNPx the more virulent strain. Considering this information and the importance of L. (L.) amazonensis in the epidemiology of leishmaniasis in Brazil, one of the goals of FAPESP 2013 / 13527-7 project, linked to this project is to analyze the importance of cTXNPx virulence of this species using models murine infection in vitro and in vivo. For this purpose, the recombinant protein obtained using the expression system and HEK293T cells superexpressores cTXNPx parasites. Our goal in collaboration with researchers from the Institut Pasteur is enzymatic and biochemically characterize the recombinant protein, test the resistance to oxidative stress superexpressor parasite and carry out a comparative proteome between parasite transfected with the empty vector and the parasite superexpressor. , Whereas overexpression of Trypanosoma cruzi cTXNPx interfere with the expression of mTXNPx and possibly other proteins of the parasite (Carlos Robello, personal communication). (AU)