Identification of Immunotopes against Mycobacterium leprae as Immune Targets Using PhDTm-12mer Phage Display Peptide Library

Purpose: To determine the surface epitopes of Mycobacterium leprae (M. leprae) and evaluate their efficacy in the production of anti-M. leprae antibodies in an animal model. Methods: Blood samples were obtained from 34 patients suffering from lepromatous leprosy. Antibodies were obtained from the samples, semi-purified and used to coat the wells of ELISA microplate, and M13 random-peptides library was added to the wells. After four rounds of panning, three clones were isolated and their peptide mimotopes were sequenced. Western blot was used to evaluate the interaction of the isolated mimotopes. Results: Three selective clones were tested by direct enzyme-linked immunosorbent assay (ELISA) and western blot. anti-leprae antibodies in various dilutions and were found to be serological active. Sequencing of the isolated peptides showed identities between the two clones that were able to successfully induce anti-Leprae humoral response in mice. Conclusion: The findings indicate that the isolated peptides can potentially be used for early diagnosis. However, further research is required to improve their potency as new vaccines against leprosy.