Screening strategy for the selection of Leishmania spp. epitopes in humans through molecular interactions analysis: A bioinformatics approach.

INTRODUCTION

The Leishmania parasite is phagocytized by macrophages and stored in the parasitophorous vacuole; therefore, the activation of Th1-CD4+ lymphocytes is essential to control the infection. Consequently, antigen presentation is critical for such activation, occurring through the binding of short parasite sequences to the MHC class II pocket.

OBJECTIVE

To identify linear sequences from immunogenic proteins of Leishmania (Viannia) spp. through bioinformatic analysis of human MHC class II molecules.

MATERIALS AND

METHODS

Linear sequences of GP63, HSP70, and PEPCK were obtained from Leishmania panamensis, and the binding of 15-mer peptides to various HLA-DRβ*04 alleles was predicted. Highly conserved sequences among parasite species with null or low analogy to human proteins were selected. Finally, molecular docking was performed against the HLA-DRβ*04:01 pocket.

RESULTS

Six sequences were initially selected as potential natural T-cell epitopes. Among these, GP63267-282, GP63282-297, and PEPCK535-550 demonstrated multiple interactions with the HLA-DR: 04:01 pocket and a consistent N-terminus to C-terminus orientation.

CONCLUSION

Three sequences were identified as potential Leishmania Th1 epitopes; however, in vitro validation is necessary to confirm these findings.