Evaluation of MHC class I-binding peptides from Leishmania spp. for vaccine development against visceral leishmaniasis.

Leishmaniasis, caused by protozoan parasites of the genus Leishmania, is a significant global health concern, with visceral leishmaniasis (VL) being its most severe clinical form. Current therapeutic options remain limited, beside of the urgent need for effective vaccines. This study identified and analyzed antigenic epitopes from Leishmania species that interact with class MHCI molecules and are recognized by T lymphocyte receptors. Peptide sequences from Leishmania species were selected from the Immune Epitope Database (IEDB) based on their interaction with MHCI molecules and ranked for immunogenicity using IEDB's predictive tools. Sequence similarities and conservation across Leishmania species were assessed using BLAST, and the peptides were synthesized via solid-phase peptide synthesis. Female BALB/c mice were immunized with the peptides, and their humoral responses were evaluated by measuring IgG titers in serum. This study identified ten peptides that, when incorporated into a vaccine construct, were capable of inducing high levels of IgG antibodies in an animal model. Among them, two stood out as immunodominant and potential targets for the development of novel vaccine strategies. These findings provide initial evidence of the potential of these peptides in developing new vaccines and therapeutic strategies against visceral leishmaniasis.