Designing a Precision Epitope-Based Vaccine Against <i>Paragonimus westermani</i> Using Immunoinformatics, Biophysical Analysis, and Molecular Modeling Approaches

Paragonimus westermani is the etiological agent of paragonimiasis and is mainly transmitted through animals by eating raw or undercooked crustaceans. Currently, no vaccines are available against paragonimiasis. This research was focused on the identification of vaccine targets using cysteine proteases of P. westermani. The ProtParam bioinformatics tool predicted that the target protein comprises 325 amino acids, with a molecular weight of 36.11641 kilodaltons, a theoretical pI, an instability index of 4.96, an aliphatic index of 30.97 and a GRAVY of −0.396; the physiochemical properties represent that the target proteins are stable and water-soluble. The immunoinformatics analysis predicted that the target protein is antigenic with a 0.4937 probable antigenic value; the AllerTOP v. 2.0 server predicted that the target is nonallergic. The cysteine proteases were used for B-cell epitope prediction and predicted four linear epitopes using the IEDB tool; the predicted epitopes were used for T-cell epitope prediction using different MHC alleles. We filtered the epitopes through antigenicity analysis, shortlisting only four antigenic epitopes for vaccine construction. The epitopes were joined by a GPGPG linker and attached with a [Formula: see text]-defensin adjuvant to make a multi-epitope vaccine construct. The vaccine was analyzed through immunoinformatics and found that the model vaccine is antigenic, nonallergic and water-soluble. The docking results indicate that the model vaccine has a good binding affinity with the immune cell receptors; thus, it can properly activate the immune system. Moreover, the C-immune simulator also unveils that the model vaccine can activate the immune system. The overall analysis using immunoinformatics, docking, biophysics and c-immune simulation indicated that the vaccine can trigger both types of immune responses and can fight against the disease caused by the target parasite.