Foot-and-Mouth disease (FMD) is a highly contagious viral disease of cloven hoofed animals which causes severe economic loss in the livestock industry when an outbreak occurs. Foot-and-Mouth Disease Virus (FMDV), an RNA virus of the picomaviridae family, is the causative agent of FMD. Although chemically inactivated FMDV vaccine has been widely used for FMD prevention, it has been implicated in the spread of the disease. Previous studies show that one of the four virus coded proteins, VPl, contains two major immunogenic sites located between residues 141-160 (20a.a.) and 200-213 (14a.a.). This project explores the possibility of creating a FMD vaccine candidate which is effective and safe. We have constructed a chimeric protein (20-14-IgG) by replacing the variable region of the heavy c...[ Read more ]

Foot-and-Mouth disease (FMD) is a highly contagious viral disease of cloven hoofed animals which causes severe economic loss in the livestock industry when an outbreak occurs. Foot-and-Mouth Disease Virus (FMDV), an RNA virus of the picomaviridae family, is the causative agent of FMD. Although chemically inactivated FMDV vaccine has been widely used for FMD prevention, it has been implicated in the spread of the disease. Previous studies show that one of the four virus coded proteins, VPl, contains two major immunogenic sites located between residues 141-160 (20a.a.) and 200-213 (14a.a.). This project explores the possibility of creating a FMD vaccine candidate which is effective and safe. We have constructed a chimeric protein (20-14-IgG) by replacing the variable region of the heavy chain of swine immunoglobulin G (IgG) with the VP1 20a.a., 14a.a. sequences. The 20-14-IgG was cloned in pET16b expression vector and expressed in Escherichia coli to produce 42kDa protein in the form of inclusion bodies. The chimeric protein was then purified using His-tagged affinity column. Different dosages of the purified protein were injected into male Balb/c mice and Large White Swine. French commercial vaccine and buffer were used as positive and negative controls, respectively. The immunogenicity of the chimeric protein was elevated in 3 areas: neutralizing antibodies level, in vitro T cell response and suckling mice protection level against FMDV. It was found that the 20-14-IgG protein was able to elicit neutralizing antibody response and T cell response in both of the mice and swine. The antisera from Fl-IgG protein inoculated swine which containing neutralizing antibody able to provide protection in suckling mice against FMDV infection up to l000LD₅₀ (Lethal Dose 50). All the results support that the Fl-IgG chimeric protein has the potential to be a novel FMD vaccine candidate.