Display Of The FMDV Neutralizing Epitope On HBc And Expression Of The Chimeric Protein By Recombinant Adenovirus

Foot-and-mouth disease (FMD) is an acute and highly contagious disease affecting cloven-hoofed animals and is characterized by widespread epidemicity, rapid transmission and great harm. Severe economic and social impacts make FMD to be a first disease listed by the World Organisation for Animal Health (OIE). In our country, it is also listed as the first one of Class I animal infectious diseases. The foot-and-mouth disease virus (FMDV) is the prototype member of the genus Aphthovirus within the family Picornaviridae. Seven distinct serotypes of the virus have been defined (O, A, C, Asial and SAT-1,2 and 3) and there is no cross-protection among serotypes.The variability of this genome is the main reason why it is difficult to prevent and control FMD.In China, vaccination is the main means of preventing and controlling FMD. Nowadays, genetically engineered vaccine become a research focus, because inactivated whole-virus vaccines that are widely used have some defects such as short duration of immunity, serious side effects and potential safety hazard. Alternative approaches have been investigated to control the disease in which vaccines based on epitopes displayed on the Virus-like Particles were expected to overcome present defects and showed bright prospects.In this study, Hepatitis B Virus core antigen (HBc) was choosed as skeleton carrier to display the neutralizing epitopes of FMDV by specific structures. Recombinant HBc spontaneously assembled into Virus-like Particles and the epitopes displayed on the surface of particles through expressing the chimeric protein in eukaryocyte. Then the reactivity of displayed epitope was detected by immunofluorescence assay (IFA). The experimental results indicated that the the best immunoreactive mimotope of Asial-type FMDV inserted in the N-terminal of HBc had high reactivity with McAb, and the neutralizing epitope of O-type FMDV inserted on MIR or N-terminal of HBc also had high reactivity with McAb. These results showed that the epitopes were display on the surface of HBc with correct conformation. Then the chimeric proteins of double epitopes and HBc were expressed well by recombinant advenvirus and had high reactivity with McAb.All the research above laid the theoretical and experimental foundation for research of epitope-displaying vaccine.