In Silico Characterization and Epitope Mapping of Echinococcus granulosus Annexin Protein: Novel Insights for Vaccine Design.

Background: A neglected zoonosis, cystic echinococcosis (CE) is the most common diseas in the developing nations worldwide. Vaccination is helpful in preventing the disease. Predicting main biochemical properties of the E. granulosus annexin (ANX) and its possible B-cell and human leukocyte antigen (HLA)-binding epitopes as a viable vaccine candidate was the goal of the current study. Methods: This study was done in Neyshabur University of Medical Sciences, Neyshabur, Iran. Predictions about transmembrane domain, subcellular localization, post-translational modification (PTM) sites, physico-chemical, antigenic, and allergenic profiles, secondary and 3D structure, tertiary model refinement, and validations were done using online servers. Results: The cytoplasmic 79.05 kDa protein was non-allergenic, hydrophilic (GRAVY: -0.490), stable (instability: 39.30), with improved thermotolerance (aliphatic: 80.07) and 122 post-translational modification sites. The secondary structure mostly included helices and extended strands. The 3D model was generated using Robetta server (confidence: 0.59) and was refined and validated subsequently. Shared B-cell epitopes were discovered using ElliPro, ABCpred and SVMTriP servers with antigenicity, allergenicity, and solubility screening. Moreover, multiple human and mouse MHC-binding epitopes were predicted and screened in E. granulosus ANX. Conclusion: This work offers a foundation for further investigation regarding designing an effective vaccination against CE. Further empirical research using examined protein alone or in conjunction with other antigens/epitopes is needed in the future.