Can Cathepsin L Epitope Be an Effective Vaccine Candidate Against Fasciola gigantica via Bioinformatics?

Background: Fasciolosis is a global parasitic disease caused by liver trematodes such as Fasciola hepatica, affecting various mammals, including sheep, goats, cattle, pigs, and humans worldwide. Cathepsin L (Cat L) found in the life stages of F. gigantica is associated with the pathology of the fluke. Given the detrimental impact of fasciolosis on animal health and production, along with reports of drug resistance and concerns regarding drug residues in animal products and the environment, there has been an increasing emphasis on developing a potent epitope-based vaccine to combat this infection. Objectives: The present study aimed at bioinformatically analyzing the characteristics of Cat L of F. gigantica newly encysted juvenile (FgNEJ) to identify potential epitopes for constructing an effective vaccine against the infection. Methods: The Cat L of FgNEJ was analyzed using several reliable bioinformatics tools. Results: Analysis of the second structure of the Cat L amino acid sequence demonstrated that the alpha-helix, random coil, and extended strand ratios were 77 (23.62%), 164 (50.31%), and 85 (26.07%), respectively. Analysis of B-cell, T-cell, and MHC epitopes predicted on the sequence suggested Cat L of FgNEJ as an ideal target for vaccine design. Conclusions: The current study introduces significant information on Cat L of FgNEJ, as well as some promising epitopes that can be used as strong candidates in studies involved in developing a vaccine against fasciolosis.