ANTIGENIC AND FUNCTIONAL STUDIES ON TRYPOMASTIGOTE SMALL SURFACE ANTIGEN OF Trypanosoma cruzi

BALOUZ V; CAMARA MM; CANEPA GE; CARMONA SJ; VOLCOVICH R; ALTCHEH J; AGÜERO F; A BUSCAGLIA, CARLOS

Mar del Plata

Congreso; X Congreso de Protozoología y Enfermedades Parasitarias; 2014

Sociedad Argentina de Protozoología y Enfermedades Parasitaria

The Trypomastigote Small Surface Antigen (TSSA) is a mucin-like molecule 27 from Trypanosoma cruzi, the etiological agent of Chagas Disease, showing amino 28 acid polymorphisms among parasite isolates. TSSA expression is restricted to the 29 surface of infective cell-derived trypomastigotes, where it functions as an adhesin, 30 engaging surface receptor(s) on the host cell as a prerequisite for parasite 31 internalization. Previous results have established TSSA-CL, the isoform encoded 32 by the CL Brener clone, as an appealing candidate for serology-based diagnostics 33 in Chagas Disease. Here, we used a combination of peptide- and recombinant 34 protein-based tools to map at maximal resolution the antigenic structure of TSSA- 35 CL. Our results indicate the presence of different, partially overlapping B-cell 36 epitope(s) clustering in the central portion of TSSA-CL, which contains most of the 37 polymorphisms across parasite isolates. Based on these results, we assessed the 38 serodiagnostic performance of a 21-amino acid long peptide spanning TSSA-CL 39 major antigenic determinants, which was similar to the performance of the 40 previously validated GST-TSSA-CL fusion molecule. Furthermore, the tools 41 developed for the antigenic characterization of the TSSA antigen were also used to 42 explore other potential diagnostic applications of the anti-TSSA humoral response 43 in Chagasic patients. Overall, our present results provide additional insights on 44 TSSA-CL antigenic structure, and support this molecule as an excellent target for 45 molecular intervention in Chagas Disease.