Gold standard serological diagnostic methods focus on
antigens that elicit a strong humoral immune response that is specific to a certain pathogen. In this study, we used bioinformatics approaches to identify linear
B-cell epitopes that are conserved among Leishmania species but are divergent from the host species Homo sapiens and Canis familiaris and from Trypanosoma cruzi, the parasite that causes
Chagas disease, to select potential targets for the immunodiagnosis of
leishmaniasis. Using these criteria, we selected
heat shock protein 83.1 of Leishmania braziliensis for this study. We predicted three linear
B-cell epitopes in its sequence. These
peptides and the recombinant
heat shock protein 83.1 (rHSP83.1) were tested in
enzyme-linked
immunosorbent assays (ELISAs) against serum samples from patients with tegumentary
leishmaniasis (TL) and
visceral leishmaniasis (VL) and from dogs infected with Leishmania infantum (canine VL [CVL]). Our data show that rHSP83.1 is a promising target in the diagnosis of TL. We also identified specific
epitopes derived from HSP83.1 that can be used in the diagnosis of human TL (
peptide 3), both human and canine VL (
peptides 1 and 3), and all TL, VL, and CVL clinical manifestations (
peptide 3). Receiver operating characteristic (ROC) curves confirmed the superior performance of rHSP83.1 and
peptides 1 and 3 compared to that of the soluble L. braziliensis
antigen and the reference test kit for the diagnosis of CVL in Brazil (EIE-LVC kit; Bio-Manguinhos, Fiocruz). Our study thus provides proof-of-principle evidence of the feasibility of using bioinformatics to identify novel targets for the immunodiagnosis of
parasitic diseases using
proteins that are highly conserved throughout evolution.