Comprehensive Analysis of Four Major Surface Proteins for Vaccine Design against Klebsiella pneumoniae

Background:Klebsiella pneumoniae (K. pneumoniae) is responsible for life-threatening infections, given that it is usually resistant to antibacterial drugs. Due to the restricted antibiotic options for the treatment of resistant K. pneumoniae infections and the critical role of humoral immune responses in preventing infectious diseases, the present in silico study aimed to investigate fimbriae (type 1 and type 3), outer membrane protein A (OmpA), and outer membrane protein K35 (OmpK35) to find appropriate epitopes for vaccine development. Materials & Methods:Several independent bioinformatics servers including IEDB, ABCpred, VaxiJen, and EMBOSS were applied to identify appropriate linear epitopes (B-cell and T-cell). Conformational epitopes were also predicted using Ellipro and Discotope programs. The Antigenic Peptide Prediction server was used to confirm the identified epitopes. Molecular characteristics, toxicity, human similarity, and allergenicity were investigated. Findings: The results demonstrated that the investigated proteins were highly immunogenic. In the first step, 25 epitopes were identified in the investigated proteins. After applying different exclusion criteria, the final epitope of each investigated protein was selected. The final epitopes of fimbriae (type 1 and type 3), OmpK35 and OmpA were located in 28-49, 26-53, 271-291, and 288-299 regions, respectively. Allergenicity, toxicity, and human similarity were negative for the predicted epitopes. Conclusion: The present study results introduced four reliable B-cell and T-cell epitopes (each for one investigated protein) with appropriate physicochemical characteristics. The proposed epitopes could be used in vaccine development against K. pneumoniae after further in vitro and in vivo studies.