Potency of a novel multi-epitope vaccine against foot-and-mouth disease type Asia 1 in guinea pigs / 中国人兽共患病学报

ABSTRACT

The potency of an improved recombinant multi-epitope vaccine against FMDV type Asia1 was evaluated in this study .A multi-epitope gene based on FMDV type Asia1 was designed and a recombinant expression plasmid (pRE-oIgG) was constructed .The proteins ,RE-oIgG and 3D were expressed in E .coli cells and purified with Ni-NTA agarose resin by affinity chromatography .The proteins ,RE-oIgG ,3D and RE-oIgG plus 3D ,were emulsified in an oil adjuvant ISA 206 .Twenty-five female guinea pigs were randomly divided into five groups and intramuscularly vaccinated for with RE-oIgG ,3D ,RE-oIgG plus 3D ,an inactivated FMDV vaccine (type Asia1) ,and PBS .All animals were vaccinated for two times .Anti-FMDV specific an-tibodies ,neutralization antibodies ,protection potency ,and lymphoproliferation assay were detected by ELISA ,virus neutrali-zation assay ,challenge test ,and flow cytometry ,respectively .Results showed that RE-oIgG plus 3D elicited significant high-level anti-FMDV specific antibodies compared to RE-oIgG alone (P<0 .05) .All the vaccinated animals induced higher level lymphoproliferation responses in vitro except PBS .Both 3D alone and PBS produced the negligible neutralizing antibodies and anti-FMDV specific antibodies .RE-oIgG plus FMDV 3D not only elicited high levels of anti-FMDV neutralizing antibodies ,but also induced significant lymphoproliferation responses .More importantly ,RE-oIgG plus 3D conferred complete protection to guinea pigs against challenge with 1 000 GPID50 .Interestingly ,two of five vaccinated animals with 3D alone were full protected against challenge ,and other three animals significantly showed a delay of 2-3 days in the onset of clinical signs .Therefore ,we considered that RE-oIgG plus 3D induces strong humoral and cellular immune responses ,which may be used for control and prevention of FMD in the future .