Preparation and immunogenicity evaluation of recombinant poliomyelitis type 2 virus-like particles / 中华微生物学和免疫学杂志

ABSTRACT

Objective:To express virus-like particles of poliovirus type 2 (PV2-VLP) in insect cells using a recombinant baculovirus expressing P1 and 3CD and to preliminarily evaluate its immunogenicity.Methods:Based on the codon preference of High 5 cells, the sequences of P1 gene and 3CD gene of PV2 were optimized and inserted into pUC57-Amp to construct pUC57-PV2-P1 and pUC57-PV2-3CD. UC57-PV2-P1s mutant that carried P1 gene mutation affecting thermostability was then constructed. Recombinant baculovirus strains of rBac-PV2-P1s-3CD and rBac-PV2-P1-3CD (wild type) were constructed using homologous recombination. The expression of target proteins was detected by Western blot. PV2-VLP was purified by ion exchange chromatography. The structure of VLP was observed under transmission electron microscopy to evaluate the assembly efficiency. The immunogenicity of PV2-VLP was assessed in a rat model.Results:The recombinant baculovirus with stable expression of P1s and 3CD proteins was successfully constructed. Western blot results showed that the yield of VLP was higher after thermostability mutation than that of the wild type. A three-dimensional structure with a diameter of about 30 nm was observed under electron microscopy, indicating that the VLP was successfully assembled. Animal experiment showed that the recombinant PV2-VLP had immunogenicity and could effectively induce the production of neutralizing antibodies.Conclusions:Effective VLP vaccines could be successfully prepared using the insect cell-baculovirus expression system, which provided reference for the development of polio VLP vaccine.