Analysis of outer membrane protein from Orientia tsutsugamushi for epitope mining

Scrub typhus, caused by Orientia tsutsugamushi, is an emerging health threat that can lead to severe complications if untreated. Therefore, it is of interest to analyse 130 sequences of the 56 kDa outer membrane protein, a key immunodominant antigen. SNP profiling identified 300 conserved and 8 highly variable residues. Epitope prediction revealed 73 conserved and 6 variable B cell epitopes, along with 4 conserved and 1 variable CD8⁺ T cell epitopes and 3 conserved and 1 variable CD4⁺ T cell epitopes. Notably, five immunogenic regions were predicted to activate B cells and both CD8⁺ and CD4⁺ T cells simultaneously. Thus, we show valuable insight into immune recognition and evasion strategies of O. tsutsugamushi. Subject to experimental validation, the identified epitopes represent promising candidates for rational vaccine development, improved serodiagnostics and novel therapeutic interventions against scrub typhus.