Comparison of immune responses against foot-and-mouth disease virus induced by fusion proteins using the swine IgG heavy chain constant region or β-galactosidase as a carrier of immunogenic epitopes

Abstract

Previously, we demonstrated that a fusion protein (Gal-FMDV) consisting of beta-galactosidase and an immunogenic peptide, amino acids (141-160)-(21-40)-(141-160), of foot-and-mouth disease virus (FMDV) VP1 protein induced protective immune responses in guinea pigs and swine. We now designed a new potential recombinant protein vaccine against FMDV in swine. The immunogenic peptide, amino acids (141-160)-(21-40)-(141-160) from the VP1 protein of serotype O FMDV, was fused to the carboxy terminus of a swine immunoglobulin G single heavy chain constant region and expressed in Escherichia coli. The expressed fusion protein (IgG-FMDV) was purified and emulsified with oil adjuvant. Vaccination twice at an interval of 3 weeks with the emulsified IgG-FMDV fusion protein induced an FMDV-specific spleen proliferative T-cell response in guinea pigs and elicited high levels of neutralizing antibody in guinea pigs and swine. All of the immunized animals were efficiently protected against FMDV challenge. There was no significant difference between IgG-FMDV and Gal-FMDV in eliciting immunity after vaccination twice in swine. However, when evaluating the efficacy of a single inoculation of the fusion proteins, we found that IgG-FMDV could elicit a protective immune response in swine, while Gal-FMDV only elicited a weak neutralizing activity and could not protect the swine against FMDV challenge. Our results suggest that the IgG-FMDV fusion protein is a promising vaccine candidate for FMD in swine.

Requirements for improved vaccines against foot-and-mouth disease epidemics

“…In addition, the methods of using human adenoviruses, bacilli, insect viruses, herpes viruses, and mammal cells have recently been introduced. Among these, some methods have shown fairly successful results, including the protective effects of replication-defective systems, such as human adenoviruses [44-53]. …”

Adenovirus-Mediated RNA Interference against Foot-and-Mouth Disease Virus Infection both In Vitro and In Vivo

“…FMD vaccines based on inactivated virus and adjuvant are effective in eliminating the disease but risk the escape of live virus from animal facilities or from improper vaccine preparations (3,22). The development of a recombinant peptide vaccine (23) and a synthetic peptide vaccine (35), both of which are safe and effective, has been reported. However, current vaccines do not induce a protective response until 7 days postvaccination, and a booster inoculation is usually needed.…”

Lentviral-mediated RNAi to inhibit target gene expression of the porcine integrin αv subunit, the FMDV receptor, and against FMDV infection in PK-15 cells

“…FMD vaccines based on inactivated virus and adjuvants are effective in eliminating the disease, but risk the escape of live viruses from animal facilities or as a consequence of improper vaccine preparations [33,42]. The development of a recombinant peptide vaccine [43] and a synthetic peptide vaccine [44]) both of which are safe and effective, has been reported. The limited effectiveness of existing vaccines and antiviral drugs means the development of new strategies is essential.…”