Abstract
Trypanosoma cruzi is a flagellate protozoan agent of Chagas disease with great importance in Latin America. T. cruzi was formerly divided into two groups occupying different ecological environments, Tc I held the wild cycle and Tc II, the domestic cycle. Currently, T. cruzi was reassembled into six distinct lineages, Tc I-VI, based on molecular studies. However, few efforts were made to characterize the biological properties and mechanisms of invasion of isolates recently regrouped. This characterization may complement the molecular studies used as basis to regroup these parasites. This parasite is characterized morphologically by presenting three distinct evolutionary stages: epimastigote, trypomastigote and amastigote, which forms the classic infective metacyclic trypomastigotes and bloodstream trypomastigotes. However, it is known that trypomastigotes derived amastigotes, regardless of the intracellular stage in the mammal, are also capable of infecting cells in vitro. These extracellular amastigotes (EA) presented specific surface antigen of amastigotes (Ssp-4), 84 kDa glycoprotein anchored to the membrane by GPI anchor, recognized by monoclonal antibody (mAb) 2C2. An interesting approach to characterize different isolates of T. cruzi is the use of mAbs that interact with carbohydrate and non carbohydrate epitopes present in the parasite. Previous comparative studies in our laboratory were elaborated in order to correlate the expression of carbohydrate and non carbohydrate epitopes recognized by mAbs produced from the immunization of mice with extracts of amastigotes from clone D11 (G strain) and infectivity of different T. cruzi strains. Thus, this work aims to characterize the expression of carbohydrate and non carbohydrate epitopes that reacts with mABs (2C2, 1D9, 2B7, 3G8, 3B9, 4B9, 3B2 and 4B5) previously obtained in our laboratory, and to correlate the expression of these epitopes with infectivity and mechanisms of invasion from different isolates belonging to distinct lineages of T. cruzi. Characterization of the expression profile of epitopes of these isolates will be performed by flow cytometry and immunofluorescence. The expression profile of epitopes will be correlated with infectivity, using the differents mAbs to evaluate their ability to block the invasion of the parasite. (AU)
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