Synthetic peptides derived from hypothetical proteins as potential antigens for the diagnosis of canine visceral leishmaniasis and tegumentary leishmaniasis

In the present study, we investigated the potential use of five linear peptides as a potential antigens for the immunodiagnosis of tegumentary leishmaniasis (TL) and canine visceral leishmaniasis (CVL). We used bioinformatics approaches to identify linear B-cell epitopes in five hypothetical proteins from a Leishmania (Leishmania) infantum proteome study. To obtain the peptide sequences of each hypothetical protein, we used the GenBank and SwissProt online databases. These peptides were synthesized and tested, alone or in a cocktail, in enzyme-linked immunosorbent assays (ELISAs) against serum samples from patients with TL and from dogs infected with CVL. Our data shows that for CVL diagnosis, the best results were found with peptides 1 and 5, which showed sensitivity values of 97.30% and 94.54%, and specificity values of 93.83% (pep 1) and 91.63% (pep 5), respectively. For TL, all peptides showed higher sensitivity and specificity when compared with SLALb, with the peptide cocktail obtaining a 99.10% accuracy. This study's outcome suggests that these peptides may constitute a potential tool for a more sensitive and specific serodiagnosis of TL and CVL.