Construction of three foot-and-mouth disease virus peptide phage display libraries as a tool for the identification of important epitopes

Abstract

Foot and mouth disease (FMD) is a transboundary animal disease that significantly impacts livestock production, particularly in sub-Saharan Africa where five of the seven FMDV serotypes exist. Eradication is deemed near impossible, thus, emphasis is mainly placed on control by vaccination and animal movement restriction. Due to the FMD virus’ (FMDV) high antigenic variation, vaccination against one serotype does not confer protection against another, mainly due to variations on the capsid coding (P1) region of the FMDV genome. Knowledge of FMDV antigenic sites can be useful to produce recombinant FMD vaccines with long-lasting immunological responses, therefore improving FMD control. Towards this end, three FMDV phage display peptide libraries were constructed using the fragmented P1 regions of SAT1, SAT2 and SAT3 viruses and biopanned against purified IgGs from FMDV infected bovine sera samples. Through biopanning, a 36-mer peptide sequence i.e., SAT3φ1 was identified, potentially forming part of a FMDV SAT3 epitope. The SAT3φ1 sequence aligned with the FMDV VP1 C-terminus, overlapping the 2A N-terminus. Further analysis revealed nine potential SAT3 antigenic sites, with four potential sites suggesting novel antigenic sites. Knowledge of these antigenic sites could aid in producing recombinant FMD vaccines with broad immunogenic response and protection. Enhanced vaccines could reduce livestock vaccination frequency, enhance trade and alleviate poverty in resource-limited communities. This study has added value to our understanding of FMDV SAT3 antigenic sites and contributes to FMD research, potentially leading to improved vaccines and livestock productivity, while alleviating poverty and enhancing food security.