Foot-and-mouth disease (FMD), caused by FMD virus (FMDV), is a highly contagious and economically devastating viral disease of cloven-hoofed animals worldwide. In this study, the coexpression of small ubiquitin-like modifier (SUMO)-fused capsid proteins of FMDV serotype O by single plasmid in Escherichia coli was achieved with an optimal tandem permutation (VP0-VP3-VP1), showing a protein yield close to 1:1:1. After SUMO removal at a low level of protease activity (5 units), the assembled FMDV virus-like particles (VLPs) could expose multiple epitopes and have a size similar to the naive FMDV. Immunization of pigs with the FMDV VLPs could induce FMDV-specific humoral and cellular immune responses effectively, in a dose-dependent manner. These data suggested that the stable FMDV VLPs with multiple epitope exposure were effective for the induction of an immune response in pigs, which laid a foundation for the further development of the FMDV subunit vaccine.
Keywords: cellular immunity; foot-and-mouth disease virus serotype O; humoral immunity; neutralizing epitopes; virus-like particles.
Copyright © 2021 Xiao, Zhang, Yan, Geng, Wang, Xu, Wang, Zhang, Huang, Pang, Yang and Tian.