An improved indirect ELISA for specific detection of antibodies against classical swine fever virus based on structurally designed E2 protein expressed in suspension mammalian cells

ABSTRACTClassical swine fever, caused by classical swine fever virus (CSFV), is a highly contagious disease that results in enormous economic losses in pig industries. The E2 protein is one of the main structural proteins of CSFV and is capable of inducing CSFV-neutralizing antibodies and cytotoxic T lymphocyte (CTL) activitiesin vivo. Thymosin α-1 (Tα1), an immune-modifier peptide, plays a very important role in the cellular immune response. In this study, genetically engineeredLactobacillus plantarumbacteria expressing CSFV E2 protein alone (L. plantarum/pYG-E2) and in combination with Tα1 (L. plantarum/pYG-E2-Tα1) were developed, and the immunogenicity of each as an oral vaccine to induce protective immunity against CSFV in pigs was evaluated. The results showed that recombinantL. plantarum/pYG-E2 andL. plantarum/pYG-E2-Tα1 were both able to effectively induce protective immune responses in pigs against CSFV infection by eliciting immunoglobulin A (IgA)-based mucosal, immunoglobulin G (IgG)-based humoral, and CTL-based cellular immune responses via oral vaccination. Significant differences (P< 0.05) in the levels of immune responses were observed betweenL. plantarum/pYG-E2-Tα1 andL. plantarum/pYG-E2, suggesting a better immunogenicity ofL. plantarum/pYG-E2-Tα1 as a result of the Tα1 molecular adjuvant that can enhance immune responsiveness and augment specific lymphocyte functions. Our data suggest that the recombinantLactobacillusmicroecological agent expressing CSFV E2 protein combined with Tα1 as an adjuvant provides a promising strategy for vaccine development against CSFV.

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Hypervariable antigenic region 1 of classical swine fever virus E2 protein impacts antibody neutralization

Vaccine ◽

10.1016/j.vaccine.2016.06.007 ◽

2016 ◽

Vol 34 (33) ◽

pp. 3723-3730 ◽

Cited By ~ 6

Author(s):

Xun Liao ◽

Zuohuan Wang ◽

Tong Cao ◽

Chao Tong ◽

Shichao Geng ◽

...

Keyword(s):

Classical Swine Fever Virus ◽

Classical Swine Fever ◽

Fever Virus ◽

Antibody Neutralization ◽

E2 Protein ◽

Antigenic Region

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Induction of immune responses in mice and pigs by oral administration of classical swine fever virus E2 protein expressed in rice calli

Archives of Virology ◽

10.1007/s00705-014-2182-4 ◽

2014 ◽

Vol 159 (12) ◽

pp. 3219-3230 ◽

Cited By ~ 4

Author(s):

Myunghwan Jung ◽

Yun Ji Shin ◽

Ju Kim ◽

Seung-Bin Cha ◽

Won-Jung Lee ◽

...

Keyword(s):

Immune Responses ◽

Oral Administration ◽

Classical Swine Fever Virus ◽

Classical Swine Fever ◽

Fever Virus ◽

E2 Protein ◽

Rice Calli

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Immunogenicity of a lettuce-derived vaccine candidate expressing the E2 protein against classical swine fever virus

Plant Cell Tissue and Organ Culture (PCTOC) ◽

10.1007/s11240-013-0290-6 ◽

2013 ◽

Vol 113 (3) ◽

pp. 483-490 ◽

Cited By ~ 3

Author(s):

Jinn-Chin Yiu ◽

Cheng-Wei Liu ◽

Ruei-Yuan Su ◽

Wan-Jun Lai ◽

Menq-Jiau Tseng ◽

...

Keyword(s):

Classical Swine Fever Virus ◽

Vaccine Candidate ◽

Classical Swine Fever ◽

Fever Virus ◽

E2 Protein

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Generation and Immunogenicity of a Recombinant Adenovirus Co-Expressing the E2 Protein of Classical Swine Fever Virus and the GP5 Protein of Porcine Reproduction and Respiratory Syndrome Virus

Agricultural Sciences in China ◽

10.1016/s1671-2927(11)60178-8 ◽

2011 ◽

Vol 10 (11) ◽

pp. 1781-1791

Author(s):

Hong-yu LI ◽

Yuan SUN ◽

Xing-juan ZHANG ◽

Tian-ming CHANG ◽

Xiang-peng WANG ◽

...

Keyword(s):

Classical Swine Fever Virus ◽

Recombinant Adenovirus ◽

Classical Swine Fever ◽

Fever Virus ◽

Respiratory Syndrome Virus ◽

E2 Protein

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Antiviral Role of IFITM Proteins in Classical Swine Fever Virus Infection

Viruses ◽

10.3390/v11020126 ◽

2019 ◽

Vol 11 (2) ◽

pp. 126 ◽

Cited By ~ 10

Author(s):

Cheng Li ◽

Hongqing Zheng ◽

Yifan Wang ◽

Wang Dong ◽

Yaru Liu ◽

...

Keyword(s):

Classical Swine Fever Virus ◽

Mammalian Cells ◽

Classical Swine Fever ◽

Fever Virus ◽

Late Endosomes ◽

Early Endosomes ◽

Infected Cells ◽

The Relationship ◽

Antiviral Role

The proteins IFITM1, IFITM2, and IFITM3 are host effectors against a broad range of RNA viruses whose roles in classical swine fever virus (CSFV) infection had not yet been reported. We investigated the effect of these proteins on CSFV replication in mammalian cells. The proteins were overexpressed and silenced using lentiviruses. Confocal microscopy was used to determine the distribution of these proteins in the cells, and immunofluorescence colocalization analysis was used to evaluate the relationship between IFITMs and the CSFV endosomal pathway, including early endosomes, late endosomes, and lysosomes. IFITM1, IFITM2, or IFITM3 overexpression significantly inhibited CSFV replication, whereas protein knockdown enhanced CSFV replication. In porcine alveolar macrophages (PAMs), IFITM1 was mainly located at the cell surface, whereas IFITM2 and IFITM3 were mainly located in the cytoplasm. Following CSFV infection, the distribution of IFITM1 changed. IFITM1, IFITM2, and IFITM3 colocalization with Lamp1, IFITM2 with Rab5 and Rab7, and IFITM3 with Rab7 were observed in CSFV-infected cells. Collectively, these results provide insights into the possible mechanisms associated with the anti-CSFV action of the IFITM family.

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