Construction And Immunological Activity Of A Chimeric Protein Carrying An Epitope Of Type 3 Poliovirus On The VP6 Of Rotavirus As A Vector

Rotavirus(RV)is the major pathogen of human and animal diarrhea.Its genome is composed of 11 segmented double-stranded RNA segments and encodes six structural proteins(VPs)and six non-structural proteins(NSPs).RV is a non-enveloped icosahedral granule containing three viral capsid layers,belonging to Reovirudae.According to the serotype of the group antigen protein VP6,existing RVs can be divided into 8 groups(A-H),wherein groups A,B,C and H can cause infection in humans.Among them,group A RV(RVA)is the main pathogen causing viral diarrhea in infants and young children.According to the degree of nucleotide homology of the coding frame(ORF)nucleotides of the 11 viral RNAs,the genes of RVA can be divided into different genotypes.At present,there are at least 27 G-type and 37 P-type genes encoding the glycoprotein VP7 and non-glycosylated spike protein VP4.VP6 is the RV group antigen protein,which is located in the intermediate layer of the virus coat,is the most conserved,and has strong antigen cross-reactivity;the abundance is the highest,accounting for about 39%of the weight of the viral structural proteins.Poliovirus(PV)belongs to the family Picornaviridae and genus Enterovirus.The genome is a positive single-stranded RNA,approximately 7.5 kb.PV is an icosahedral virus particle composed of 60 structural proteins and encodes a total of four structural proteins of VP4,VP2,VP3,and VP1,and 7 non-structural proteins,2A,2B,2C,and 3A.,3B,3C and 3D.According to the antigenicity variality of strains,PVs are divided into three serotypes,type Ⅰ(PV1),Ⅱ(PV2)and Ⅲ(PV3),and there is less cross-immune reaction between the three serotypes.Humans are the only natural host of polioviruses.PVs can cause asymmetrical flaccid paralysis of limb muscles,known as polio.Since there are still certain drawbacks in the existing RV and PV vaccines,the development of new vaccines is a current trend.In this study,we used gene cloning and recombinant technology to insert an epitope of PV3 into the RV VP6 protein as a vector to construct a chimeric protein 6F/PV3N1.The chimeric protein was expressed in E.coli and detected by Western-blot assay.The results provide a very useful basis for the development of new vaccines that can simultaneously prevent RV and PV infections.