Potent Protective Immune Responses to Senecavirus Induced by Virus-Like Particle Vaccine in Pigs.

Suyu Mu,Shuanghui Yin,Shiqi Sun,Zhidong Teng,Yun Zhang,Hu Dong,Mei Ren,Huichen Guo,Manyuan Bai

doi:10.3390/vaccines8030532

Suyu Mu, Shuanghui Yin + Show 7 more

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https://doi.org/10.3390/vaccines8030532

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Abstract

Senecavirus A (SVA) is the pathogen that has recently caused porcine idiopathic vesicular disease (PIVD). The clinical symptoms of PIVD are similar to those of acute foot-and-mouth disease and also can result in the death of newborn piglets, thus entailing economic losses. Vaccine immunization is the most effective way to prevent and control SVA. Among all SVA vaccines reported, only the SVA inactivated vaccine has been successfully developed. However, to ensure the elimination of this pathogen, safer and more effective vaccines are urgently required. A virus-like particles (VLPs)-based vaccine is probably the best alternative to inactivated vaccine. To develop an SVA VLPs vaccine and evaluate its immune effect, a prokaryotic expression system was used to produce SVA capsid protein and assemble VLPs. The VLPs were characterized by affinity chromatography, sucrose density gradient centrifugation, ZetaSizer and transmission electron microscopy. Meanwhile, the SVA CH-HB-2017 strain was used to infect pigs and to determine infection routes and dose. Experimental pigs were then immunized with the SVA VLPs vaccine emulsified in an ISA 201 adjuvant. The results showed that the VLPs vaccine induced neutralizing and specific antibodies at similar levels as an inactivated SVA vaccine after immunization. The level of INF-γ induced by the VLPs vaccine gradually decreased—similar to that of inactivated vaccine. These results indicated that VLPs vaccine may simultaneously cause both cellular and humoral immune responses. Importantly, after the challenge, the VLPs vaccine provided similar levels of protection as the inactivated SVA vaccine. In this study, we successfully obtained novel SVA VLPs and confirmed their highly immunogenicity, thus providing a superior candidate vaccine for defense and elimination of SVA, compared to the inactivated vaccine.

Highlights

Senecavirus A (SVA)— known as Seneca Valley virus (SVV)—was isolated from contaminatedPER.C6 cells in 2002 [1]
Later studies found that the clinical symptoms of porcine idiopathic vesicular disease (PIVD) caused by SVA that were very similar to those of foot-and-mouth disease (FMD), swine vesicular disease (SVD), swine vesicular herpes and swine vesicular stomatitis virus
We have successfully developed virus-like particles (VLPs) of Foot-and-mouth disease virus (FMD), Porcine circovirus 2 (PCV2), Rabbit hemorrhagic fever virus (RHDV), Porcine parvovirus (PPV) and Canine parvovirus (CPV) using an E. coli expression vector [20,21,22,23]

Summary

Introduction

Senecavirus A (SVA)— known as Seneca Valley virus (SVV)—was isolated from contaminated. PER.C6 cells in 2002 [1] This virus was first reported associated with porcine idiopathic vesicular disease (PIVD) in Canada [2]. PCR identification and virus isolation confirmed that several samples from diseased animals contained SVA, but no other pathogens. Later studies found that the clinical symptoms of PIVD caused by SVA that were very similar to those of foot-and-mouth disease (FMD), swine vesicular disease (SVD), swine vesicular herpes and swine vesicular stomatitis virus. Vaccines 2020, 8, 532 disease requiring an immediate report, SVA has attracted great attention. Far, SVA has spread widely in Canada [2], USA [3], Brazil [4], China [5], Thailand [6], Colombia [7] and Vietnam [8]

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