Evaluation of the Antigenic Potential of Epitopes Derived From Leishmania braziliensis.

Background: Leishmaniasis is a neglected tropical disease caused by protozoa of the genus Leishmania, predominantly affecting populations with limited socioeconomic resources. Leishmania (V.) braziliensis is one of the primary etiological agents for cutaneous leishmaniasis (CL) in Brazil. This study aims to evaluate the interactions between IgG antibodies and 10 antigens derived from L braziliensis for diagnostic applications. These antigens were selected using in silico reverse vaccinology approaches, based on previous research conducted by our group. Methods: A total of 124 IgG antibody structures were retrieved from the SAbDab database. Antigen-antibody (Ag-Ab) complexes were subjected to molecular docking analyses using the SnugDock protocol implemented in the Rosetta platform. In parallel, enzyme-linked immunosorbent assays (ELISA) were performed to assess the diagnostic performance of the selected peptides in detecting active CL. Results: Peptides VIII, VI, V, and I showed the most favorable docking scores, indicating a higher predicted binding affinity with IgG. In ELISA assays, sensitivity values ranged from 0% to 96%, whereas specificity varied from 29% to 86%. Peptides III, IV, and V demonstrated the highest sensitivity, achieving values of 96%, 96%, and 94%, respectively. Conclusions: Considering both in silico and in vitro results, peptides IV and V corroborate significatively, demonstrating higher predicted affinity (more negative docking score values) with the set of antibodies (Ab) used in calculations.