Fusion expression of Asia I type FMDV neutralizing epitope with heavy chain constant region of sheep IgG and the assessment of its immunogenicity

Abstract:

VP1 is a major antigenic protein of foot-and-mouth disease virus(FMDV), which induces the immune response against FMDV infection, and contains several epitopes of the virus. we designed and chemically synthesized a DNA fragment which encoding a tandem repeat protein of 136?160aa and 198?211aa of a strain of type Asia I FMDV, and cloned the gene of heavy chain constant region of sheep IgG. By using the BamH I, EcoR I and Xho I sites, both genes were cloned into pPROExHTb vector in turn to form a recombinant plasmid pPRO-FshIgG. A chimeric protein, named FshIgG, was obtained after transforming the pPRO-FshIgG into Escherichia coli BL21 (DE3) host cell and induced by IPTG. Inoculation with 100 μg FsIgG induced strong neutralizing antibody response in guinea pigs, and FshIgG inoculated guinea pigs were also protected against 200 ID50 FMDV challenge. Our study indicated that the heavy chain constant region of sheep IgG can act as the carrier protein for FMDV peptide epitopes, and FshIgG is a potential multiepitope peptide vaccine candidate to prevent FMDV infection.