Background: Mycobacterium avium sp. paratuberculosis (MAP) causes Paratuberculosis (pTB) in domestic livestock
and has also been associated with auto-immune disorders in humans. Infection leads to huge economic losses to the
farmers associated with livestock production system worldwide. Currently, search to find proteins with potential to develop
as vaccine candidates against MAP are underway.
Objective: In this study, we aimed to explore the immunogenicity of the proteins of mammalian cell entry (mce) operons of
MAP using computational tools.
Method: Genes of mce operons of MAP strain K10 were selected and their orthologs identification was done using VFanalyzer
tool. Mce proteins encoded by these operons were analyzed for their antigenicity and sub-cellular localization. Three
dimensional structures for Mce proteins were predicted using Phyre2. B cell and T cell epitope analysis was done using
methods available at Immune Epitope Database and Analysis Resource. Selection analysis of mce genes was also done.
Results: Eight Mce proteins were predicted with B cell and T cell epitopes. Some of them were reported with overlapping B
cell and T cell epitopes. We found positively selected sites within some predicted epitopes that indicated some kind of selection
pressure by immune system on these protein regions. Some predicted epitopes also had similarity with experimentally
identified epitopes of Mce proteins of M. tuberculosis which further strengthened the immunogenic role of Mce proteins.
Conclusion: Our findings may potentially assist in the development of effective vaccine against the incurable infection due
to MAP bacilli in the domestic livestock species.