Preparation and identification of the epitope peptide polyclonal antisera against capsid proteins of EV71

Abstract

Objective To prepare polyclonal antisera against enterovirus 71(EV71) capsid proteins. Methods Five B cell epitope prediction softwares were used to analyze capsid proteins of EV71 and four peptides against viral protein were synthesized, VP1(aa.204-223), VP2(aa.133-163), VP3(aa.139-148+aa.173-191) and VP4(aa.1-23). They were conjugated with keyhole limpet hemocyanin(KLH). BALB/c mice were subcutaneously immunized with six doses of KLH-peptides adjuvanted with MF59/CpGC274 at two-week interval. Serum sample was collected and examined with ELISA and Western blot. Results The four antisera were bound to both EV71 virus and denatured virus effectively. VP2 antiserum showed activity with denatured virus and the other three had similar binding activity to EV71 virus and denatured virus. The four antiserum samples were bound to both EV71 virus-like particle (VLP) and denatured VLP effectively. VP1 and VP2 antiserum could bind to VP1, VP0 of EV71 VLP separately. VP2 antiserum showed the highese binding activity and VP1 antiserum showed a inperior binding activity as compared to the formers. VP1 and VP2 antiserum were bound specifically and efficiently to EV71 virus. VP0 of empty particles and VP2 of intact EV71 virus particles could be simultaneously identified by VP2 antiserum. VP3 and VP4 antiserum failed to binding to no obvious binding to VLP and virus. Conclusions Four epitope peptide polyclonal antisera against EV71 are successfully prepared, which can provide ootential detection tools used in ELISA and Western blot and may be used for QC evaluation of EV71 vaccine.

Keywords

• enterovirus 71|vaccine|capsid protein|epitope peptide|antiserum