scholarly journals Decrypting the Origin and Pathogenesis in Pregnant Ewes of a New Ovine Pestivirus Closely Related to Classical Swine Fever Virus

Viruses ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 775 ◽  
Author(s):  
Miaomiao Wang ◽  
Enrica Sozzi ◽  
José Alejandro Bohórquez ◽  
Mònica Alberch ◽  
Joan Pujols ◽  
...  
Keyword(s):  
Antibody Response ◽  
Classical Swine Fever Virus ◽  
Animal Health ◽  
High Capacity ◽  
Classical Swine Fever ◽  
Neutralizing Antibody ◽  
Cross Reactivity ◽  
Fever Virus ◽  
Genotype 2 ◽  
Multiple Species

This study shows the origin and the pathogenic role of a novel ovine pestivirus (OVPV) isolated in 2017 in Italy, as a pathogenic agent causing severe abortions after infection in pregnant ewes and high capacity for virus trans-placental transmission as well as the birth of lambs suffering OVPV-persistent infection. The OVPV infection induced early antibody response detected by the specific ELISA against classical swine fever virus (CSFV), another important virus affecting swine. The neutralizing antibody response were similar against CSFV strains from genotype 2 and the OVPV. These viruses showed high identity in the B/C domain of the E2-glycoprotein. Close molecular diagnostics cross-reactivity between CSFV and OVPV was found and a new OVPV molecular assay was developed. The phylodynamic analysis showed that CSFV seems to have emerged as the result of an inter-species jump of Tunisian sheep virus (TSV) from sheep to pigs. The OVPV and the CSFV share the TSV as a common ancestor, emerging around 300 years ago. This suggests that the differentiation of TSV into two dangerous new viruses for animal health (CSFV and OVPV) was likely favored by human intervention for the close housing of multiple species for intensive livestock production.

scholarly journals Generation and immunogenicity analysis of recombinant classical swine fever virus glycoprotein E2 and Erns expressed in baculovirus expression system

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Qiang Wei ◽  
Yilin Bai ◽  
Yapeng Song ◽  
Yunchao Liu ◽  
Wei Yu ◽  
...  
Keyword(s):  
Immune Responses ◽  
Classical Swine Fever Virus ◽  
Expression System ◽  
Classical Swine Fever ◽  
Neutralizing Antibody ◽  
Baculovirus Expression System ◽  
Viral Envelope ◽  
Fever Virus ◽  
Complete Protection ◽  
Glycoprotein E2

AbstractClassical swine fever (CSF) caused by the classical swine fever virus (CSFV) is a highly contagious swine disease resulting in large economical losses worldwide. The viral envelope glycoprotein E2 and Erns are major targets for eliciting antibodies against CSFV in infected animals. In this report, the glycoprotein E2 and Erns were expressed using the baculovirus system and their protective immunity in rabbits were tested. Twenty CSFV seronegative rabbits were randomly divided into five groups. Each rabbit was intramuscularly immunized with CSFV-E2, CSFV-Erns, or their combination (CSFV-E2 + Erns). Besides, a commercial CSFV vaccine (C-strain) and PBS were used as positive or negative controls, respectively. Four weeks after the second immunization, all the rabbits were challenged with 100 RID50 of CSFV C-strain. High levels of CSFV E2-specific antibody, neutralizing antibody and cellular immune responses to CSFV were elicited in the rabbits inoculated with C-strain, CSFV-E2, and CSFV-E2 + Erns. And the rabbits inoculated with the three vaccines received complete protection against CSFV C-strain. However, no neutralizing antibody was detected in the Erns vaccinated rabbits and the rabbits exhibited fever typical of CSFV, suggesting the Erns alone is not able to induce a protective immune response. Taken together, while the Erns could not confer protection against CSFV, E2 and E2 + Erns could not only elicit humoral and cell-mediated immune responses but also confer complete protection against CSFV C-strain in rabbits.

scholarly journals Mutation of Cysteine 171 of Pestivirus Erns RNase Prevents Homodimer Formation and Leads to Attenuation of Classical Swine Fever Virus

2009 ◽  
Vol 83 (10) ◽  
pp. 4823-4834 ◽  
Author(s):  
Birke Andrea Tews ◽  
Eva-Maria Schürmann ◽  
Gregor Meyers
Keyword(s):  
Classical Swine Fever Virus ◽  
Gel Electrophoresis ◽  
Bond Formation ◽  
Classical Swine Fever ◽  
Neutralizing Antibody ◽  
Fever Virus ◽  
Farm Animals ◽  
Protein Gel ◽  
Intermolecular Disulfide Bond ◽  
Infected Cells

ABSTRACT Pestiviruses represent important pathogens of farm animals that have evolved unique strategies and functions to stay within their host populations. Erns, a structural glycoprotein of pestiviruses, exhibits RNase activity and represents a virulence factor of the viruses. Erns forms disulfide linked homodimers that are found in virions and virus-infected cells. Mutation or deletion of cysteine 171, the residue engaged in intermolecular disulfide bond formation, results in loss of dimerization as tested in coprecipitation and native protein gel electrophoresis analyses. Nevertheless, stable virus mutants with changes affecting cysteine codon 171 could be recovered in tissue culture. These mutants grew almost as well as the parental viruses and exhibited an RNase-positive phenotype. Erns dimerization-negative mutants of classical swine fever virus were found to be attenuated in pigs even though the virus clearly replicated and induced a significant neutralizing antibody response in the animals.

scholarly journals Genotyping and Molecular Characterization of Classical Swine Fever Virus Isolated in China during 2016–2018

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 664
Author(s):  
Madiha Fatima ◽  
Yuzi Luo ◽  
Li Zhang ◽  
Peng-Ying Wang ◽  
Hao Song ◽  
...  
Keyword(s):  
Classical Swine Fever Virus ◽  
Classical Swine Fever ◽  
Fever Virus ◽  
Full Genome ◽  
Genotype 1 ◽  
E2 Gene ◽  
The Past ◽  
Genotype 2 ◽  
Modified Live Vaccine

Classical swine fever (CSF) is a highly contagious disease of swine caused by classical swine fever virus (CSFV). For decades the disease has been controlled in China by a modified live vaccine (C-strain) of genotype 1. The emergent genotype 2 strains have become predominant in China in the past years that are genetically distant from the vaccine strain. Here, we aimed to evaluate the current infectious status of CSF, and for this purpose 24 isolates of CSFV were identified from different areas of China during 2016–2018. Phylogenetic analysis of NS5B, E2 and full genome revealed that the new isolates were clustered into subgenotype 2.1d and 2.1b, while subgenotype 2.1d was predominant. Moreover, E2 and Erns displayed multiple variations in neutralizing epitope regions. Furthermore, the new isolates exhibited capacity to escape C-strain-derived antibody neutralization compared with the Shimen strain (genotype 1). Potential positive selection sites were identified in antigenic regions of E2 and Erns, which are related with antibody binding affinity. Recombination events were predicted in the new isolates with vaccine strains in the E2 gene region. In conclusion, the new isolates showed molecular variations and antigenic alterations, which provide evidence for the emergence of vaccine-escaping mutants and emphasize the need of updated strategies for CSF control.

scholarly journals Identification of a Common Conformational Epitope on the Glycoprotein E2 of Classical Swine Fever Virus and Border Disease Virus

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1655
Author(s):  
Yu-Liang Huang ◽  
Denise Meyer ◽  
Alexander Postel ◽  
Kuo-Jung Tsai ◽  
Hsin-Meng Liu ◽  
...  
Keyword(s):  
Disease Virus ◽  
Classical Swine Fever Virus ◽  
Classical Swine Fever ◽  
Conformational Epitope ◽  
Cross Reactivity ◽  
Fever Virus ◽  
Site Directed Mutagenesis ◽  
Border Disease Virus ◽  
Diarrhea Virus ◽  
Border Disease

Classical swine fever virus (CSFV) shares high structural and antigenic homology with bovine viral diarrhea virus (BVDV) and border disease virus (BDV). Because all three viruses can infect swine and elicit cross-reactive antibodies, it is necessary to differentiate among them with regard to serological diagnosis of classical swine fever. To understand the mechanism of cross-reactivity, it is important to define common or specific epitopes of these viruses. For this purpose, epitope mapping of six monoclonal antibodies (mAbs) was performed using recombinant expressed antigenic domains of CSFV and BDV E2 proteins. One CSFV-specific conformational epitope and one CSFV and BDV common epitope within domain B/C of E2 were identified. Site-directed mutagenesis confirmed that residues G725 and V738/I738 of the CSFV-specific epitope and P709/L709 and E713 of the second epitope are important for mAbs binding. Infection of CSFV in porcine cells was significantly reduced after pre-incubation of the cells with the domain B/C of E2 or after pre-incubation of CSFV with the mAbs detecting domain B/C. 3D structural modeling suggested that both epitopes are exposed on the surface of E2. Based on this, the identified epitopes represent a potential target for virus neutralization and might be involved in the early steps of CSFV infection.

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