Novel recombinant antigens of Leishmania (Viannia) braziliensis for leishmaniasis immunodiagnosis

BRACAMONTE MARIA ESTEFANIA; BARROSO PAOLA ANDREA; ACUÑA LEONARDO; CAJAL SP; AGUSTIN MOYA ALVAREZ; RANGO DANIELA; UNCOS RENATO; MARCO JORGE DIEGO

Parana, Entre Rios

Congreso; 54th Annual Meeting Agentine Society for Biochemistry and Molecular Biology LIV Reunion Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2018

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

Leishmania (Viannia) braziliensis is the main causative agent of American tegumentary leishmaniasis (ATL) in Argentina. Despite of thedevelopment of molecular methods, nowadays its diagnosis remains as a challenge. In this work we applied seroproteomic approaches for theselection and identification of L. (V.) braziliensis antigen candidates, for sensitive and specific immunodiagnoses of this endemic disease. By twodimensional Western blots of amastigote extract of L. (V). braziliensis , three antigen candidates were selected for their differential reactivityagainst sera from patients with ATL and non-reactive with Chagas disease, which cross-reaction have been previously reported. They wereidentified by Mass Spectrometry and Fingerprinting analysis. One of them was overexpressed in Escherichia coli, purified and used forserological tests. To analyze their immunological performance, sera from ATL patients and 52 from non ATL cases were included in this study.The antigen selected was termed HAT-LbAg1 (50.2 kDa, IP 5.2). The sensitivity - specificity of this antigen immunoblotting and ELISA were80.5 - 90.5% and 70.7- 72, 88% respectively. With this molecular methods of identification of new candidates to ATL diagnosis, the crossreactionwith Chagas disease was reduced, increasing the specificity values of the immunoblotting technique. On the other hand, the sensitivitypercentage can be improved by the combination with other candidates to diagnose true positives cases of ATL. Further studies are necessary toknow the performance of HAT-LbAg1 and the other candidates in their application in novel immunological techniques.