Immunogenicity of porcine circovirus type 2 nucleic acid vaccine containing CpG motif for mice.

Jun Li,Zhe Peng,Shuxuan Zheng,Jinbao Wang,Shengnan Xu,Jiang Yu,Lingling Zhang,Wenbo Sun,Jiaqiang Wu,Xiaoyan Wu,Xiaoyuan Yuan,Xiaoyan Cong,Kaihui Cheng,Yijun Du,Jianli Shi,Fang Fu,Shaojian Xu

doi:10.1186/s12985-016-0597-0

Abstract

BackgroundThis study aimed at reseaching the immune effect of porcine circovirus type 2 (PCV2) DNA vaccine containing CpG motif on mice.MethodsA total of 40 6-week-old female BALB/c mice were randomly divided into four groups which were immunized by 18CpG-pVAX1-ORF2, pVAX1-ORF2, pVAX1 and PBS, respectively, and immunized again 2 weeks later. All mice were challenged with 0.2 mL PCV2 cells virulent strain SD (106.0 TCID50/mL) after 4 weeks. Average daily gain, blood antibody levels, microscopic changes and viremia were detected to estimate the effect of DNA vaccine.Results and DiscussionThe results showed that compared to those of the control mice, groups immunized with pVAX1-ORF2 and 18CpG-pVAX1-ORF2 could induce PCV2-specific antibodies. The PCV2-specific antibodies level of 18 CpG-pVAX1-ORF2 groups was higher significantly than other groups and decreased slowly along with time. There was no distinct pathological damage and viremia occurring in mice that inoculated with CpG motif DNA vaccines. The results demonstrated that the DNA vaccine containing 18 CpG could build up resistibility immunity and reduce immune organ damage on mice.

Highlights

This study aimed at reseaching the immune effect of porcine circovirus type 2 (PCV2) DNA vaccine containing CpG motif on mice
The most successful vaccine candidates were those based on the induction of an active immune response against the capsid protein of PCV2 [5,6,7]
In this study,we evaluate immune effect of PCV2 DNA vaccine with CpG motif on mice using the best CpG motif from our earlier research [10], which can provide a great prospect for preventing and controlling porcine circovirus diseases (PCVD),in order to give candidate vaccine evaluation model

Summary

Introduction

This study aimed at reseaching the immune effect of porcine circovirus type 2 (PCV2) DNA vaccine containing CpG motif on mice. PCV comprises with two genotypes, which are non-pathogenic PCV1 and pathogenic PCV2 [1]. The former exist widely in PK-15 cells, and the latter is closely related with postweaning multisystemic wasting syndrome (PMWS) [2], which mainly infect weaned pigs and fattening pigs. Porcine circovirus type 2 (PCV2) has become one of the most important pathogens affecting the swine industry worldwide [3]. ORF1 encodes the Currently, PCV2 vaccination is still an important method to combat porcine circovirus diseases (PCVD). The most successful vaccine candidates were those based on the induction of an active immune response against the capsid protein of PCV2 [5,6,7]

Objectives

Methods

Results