Trypanosoma Cruzi Multiepitope Chimeric Protein as Sensitizing Antigen for Immunoagglutination Assays

CAUDANA, PAMELA C.; GONZALEZ, VERÓNICA D.G.; MARCIPAR, IVAN S.; GUGLIOTTA, LUIS M.

San José

Simposio; XII Simposio Latinoamericano de Polímeros / X Congreso Iberoamericano de Polímeros - SLAP 2010; 2010

Laboratorio de Polímeros –POLIUNA / Universidad Nacional de Costa Rica / Laboratorio Nacional de Nanotecnología LANOTEC / Centro Nacional de Alta Tecnología - CeNAT

Immunological methods are nowadays the elective procedure to diagnose Chagas’ disease. This illness caused by infection with the parasite Trypanosoma cruzi, affects between 16 and 18 million people only in Latin America, with a further 100 million considered at risk. Chagasic infection is mostly diagnosed when specific antibodies (Abs) against T. cruzi antigens (Ags) are detected in patient’s blood. Total homogenate of the parasite at the epimastigote stage provides Ags for serological tests, since it was proved to render the appropriate sensitivity to detect low Ab levels. However, when using this complex mixture of variable, largely undefined Ags, not only specificity problems appear but also difficulties to standardize the methodology. The current trend is using recombinant proteins as sensitizing elements, since large amounts of them can be obtained in a highly purified form, and additionally, they can be synthesized from DNA sequences engineered to encode peptide fragments where the specific regions responsible of cross-reactivity have been excised. Bearing in mind the sensitivity loss when using single recombinant peptides, several authors have suggested that a peptide mixture would reach a sensitivity equal to the sum of that of the individual Ags. Alternatively, the use of multiepitope proteins expressing several unrelated antigenic determinants has also been proposed to enhance sensitivity. With the final aim of producing an immunodiagnosis kit for the Chagas disease, this work describes the sensitization of a core-shell carboxylated latex by covalent coupling with the multiepitope chimeric protein CP2 of T. cruzi. The chemical coupling of proteins avoids the potential desorption and denaturalization of the physically adsorbed proteins. Moreover, the hydrophilic nature of the functionalized latex prevents nonspecific latex-protein interactions.