title: Mapping antigenic motifs in the trypomastigote small surface antigen from Trypanosoma cruzi.
abstract: The trypomastigote small surface antigen (TSSA) is a mucin-like molecule from Trypanosoma cruzi, the etiological agent of Chagas disease, which displays amino acid polymorphisms in parasite isolates. TSSA expression is restricted to the surface of infective cell-derived trypomastigotes, where it functions as an adhesin and engages surface receptors on the host cell as a prerequisite for parasite internalization. Previous results have established TSSA-CL, the isoform encoded by the CL Brener clone, as an appealing candidate for use in serology-based diagnostics for Chagas disease. Here, we used a combination of peptide- and recombinant protein-based tools to map the antigenic structure of TSSA-CL at maximal resolution. Our results indicate the presence of different partially overlapping B-cell epitopes clustering in the central portion of TSSA-CL, which contains most of the polymorphisms found in parasite isolates. Based on these results, we assessed the serodiagnostic performance of a 21-amino-acid-long peptide that spans TSSA-CL major antigenic determinants, which was similar to the performance of the previously validated glutathione S-transferase (GST)-TSSA-CL fusion molecule. Furthermore, the tools developed for the antigenic characterization of the TSSA antigen were also used to explore other potential diagnostic applications of the anti-TSSA humoral response in Chagasic patients. Overall, our present results provide additional insights into the antigenic structure of TSSA-CL and support this molecule as an excellent target for molecular intervention in Chagas disease.
authors.affiliation: Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECh), Universidad Nacional de San Martín (UNSAM), and Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Campus UNSAM, San Martín, Buenos Aires, Argentina.
authors.forename: Virginia
authors.initials: V
authors.lastname: Balouz
authors.affiliation: Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECh), Universidad Nacional de San Martín (UNSAM), and Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Campus UNSAM, San Martín, Buenos Aires, Argentina.
authors.forename: María de Los Milagros
authors.initials: Mde L
authors.lastname: Cámara
authors.affiliation: Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECh), Universidad Nacional de San Martín (UNSAM), and Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Campus UNSAM, San Martín, Buenos Aires, Argentina.
authors.forename: Gaspar E
authors.initials: GE
authors.lastname: Cánepa
authors.affiliation: Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECh), Universidad Nacional de San Martín (UNSAM), and Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Campus UNSAM, San Martín, Buenos Aires, Argentina.
authors.forename: Santiago J
authors.initials: SJ
authors.lastname: Carmona
authors.affiliation: Laboratorio de Parasitología-Chagas, Hospital de Niños Dr. Ricardo Gutiérrez, Buenos Aires, Argentina.
authors.forename: Romina
authors.initials: R
authors.lastname: Volcovich
authors.affiliation: Laboratorio de Parasitología-Chagas, Hospital de Niños Dr. Ricardo Gutiérrez, Buenos Aires, Argentina.
authors.forename: Nicolás
authors.initials: N
authors.lastname: Gonzalez
authors.affiliation: Laboratorio de Parasitología-Chagas, Hospital de Niños Dr. Ricardo Gutiérrez, Buenos Aires, Argentina.
authors.forename: Jaime
authors.initials: J
authors.lastname: Altcheh
authors.affiliation: Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECh), Universidad Nacional de San Martín (UNSAM), and Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Campus UNSAM, San Martín, Buenos Aires, Argentina.
authors.forename: Fernán
authors.initials: F
authors.lastname: Agüero
authors.affiliation: Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECh), Universidad Nacional de San Martín (UNSAM), and Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Campus UNSAM, San Martín, Buenos Aires, Argentina cbuscaglia89@gmail.com.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Buscaglia
mesh_terms: D000595:Amino Acid Sequence; D000913:Antibodies, Protozoan / Q000097:blood*; D014355:Chagas Disease / Q000151:congenital / Q000175:diagnosis* / Q000276:immunology; D018604:Epitope Mapping; D018985:Epitopes, B-Lymphocyte; D005982:Glutathione Transferase; D006801:Humans; D010449:Peptide Mapping; D010455:Peptides / Q000276:immunology; D040081:Protein Array Analysis; D017434:Protein Structure, Tertiary; D012372:ROC Curve; D011993:Recombinant Fusion Proteins / Q000276:immunology; D014349:Trypanosoma cruzi / Q000737:chemistry* / Q000276:immunology*; D014643:Variant Surface Glycoproteins, Trypanosoma / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*
chemical_list: D000913:Antibodies, Protozoan; D018985:Epitopes, B-Lymphocyte; D010455:Peptides; D011993:Recombinant Fusion Proteins; D014643:Variant Surface Glycoproteins, Trypanosoma; C573505:trypomastigote small surface antigen, Trypanosoma cruzi; D005982:Glutathione Transferase