Immunochemical characterization of antigens with serological cross-reactivity in trypanosomes

Trypanosomatidae is a group of protozoa belonging to Trypanosomatida order, where the genres of medical importance Leishmania and Trypanosoma are inserted. These genres include parasites Leishmania spp., Trypanosoma cruzi and Trypanosoma brucei, etiologic agents of leishmaniasis, Chagas disease and sleeping sickness, respectively classified as Neglected Tropical Diseases (NTDs) by the World Health Organization (WHO). The diagnostic methods used so far for the detection of these diseases are essentially serological tests, where cross-reactions often occur, since there are antigens shared among the three populations of trypanosomatids. In this sense, this work aimed to characterize and identify antigens of the three trypanosomatids (Leishmania spp., T. cruzi and T. brucei) responsible for the development and maintenance of humoral immunity during the stages of infection and involved in serological cross-reactivity and serological specific reactivity (anti-Leishmania spp., anti-T. cruzi and anti-T. brucei) of different populations. To this end, samples of experimentally infected mice sera and of naturally infected human and canine, with one of three types of trypanosomatids, were used. The results obtained after characterization and crossing of the polyclonal antisera produced, demonstrated the existence of serological cross-reactivity essentially between the four species of Leishmania studied and between T. cruzi Y and T. b. brucei. In what regards the characterization and identification of antigens, there have been identified some antigens with cross-reactivity, where the antigens with molecular weight of approximately 88, 77, 75, 25 and 20 kDa have special relevance. Later, by conducting an analysis in silico, it should be possible to identify the proteins highlighted in the context of this study and there could contribute for the development of new diagnosis methods. Key-words: Leishmania spp., Trypanosoma cruzi, Trypanosoma brucei, Leishmaniasis, Chagas Disease, Sleeping sickness, cross-reactivity.