Cytotoxicity effect and transcriptome analysis of PCV3-infected cells revealed potential viral pathogenic mechanisms.

Porcine circovirus type 3 (PCV3) has become an important pathogen in the global swine industry and poses a threat to pig health, but its pathogenic mechanism remains unknown. In this study, we constructed an innovative, linear infectious clone of PCV3 for rescuing the virus, and explored the transcriptome of infected cells to gain insights into its pathogenic mechanisms. Subsequently, an in vivo experiment was conducted to evaluate the pathogenicity of the rescued virus in pig.

Exploring the surface epitope and nuclear localization analysis of porcine circovirus type 3 capsid protein.

Porcine circovirus 3 (PCV3) is a newly emerging virus associated with porcine dermatitis and nephropathy syndrome (PDNS) and reproductive disorders, impacting global pig populations. Porcine circoviruses contain two major open reading frames (ORFs), and the ORF2 encodes the viral capsid protein (Cap). Cap is the most antigenic structural protein and an ideal candidate for the development of vaccines and diagnostic reagents.

A prospective CSFV-PCV2 bivalent vaccine effectively protects against classical swine fever virus and porcine circovirus type 2 dual challenge and prevents horizontal transmission.

Classical swine fever virus (CSFV) infection leading to CSF outbreaks is among the most devastating swine diseases in the pig industry. Porcine circovirus type 2 (PCV2) infection, resulting in porcine circovirus-associated disease (PCVAD), is also a highly contagious disease affecting pig health worldwide. To prevent and control disease occurrence, multiple-vaccine immunization is necessary in contaminated areas or countries.

Effectiveness of Live-Attenuated Genotype III Japanese Encephalitis Viral Vaccine against Circulating Genotype I Viruses in Swine.

Expansion of genotype I (GI) Japanese encephalitis viruses (JEV) has resulted in the replacement of the dominant genotype III (GIII) viruses, raising serious public health concerns for using GIII virus-derived vaccines to effectively control JEV epidemics. Therefore, this study used swine as the model to estimate the effectiveness of GIII live-attenuated vaccine against GI virus infection by comparing the incidence of stillbirth/abortion in gilts from vaccinated and non-vaccinated pig farms during the GI-circulation period. In total, 389 and 213 litters of gilts were recorded from four vaccinated and two non-vaccinated pig farms, respectively.

Evaluation of classical swine fever E2 (CSF-E2) subunit vaccine efficacy in the prevention of virus transmission and impact of maternal derived antibody interference in field farm applications.

Background: Classical swine fever (CSF) is one of the most devastating pig diseases that affect the swine industry worldwide. Besides stamping out policy for eradication, immunization with vaccines of live attenuated CSF or the CSF-E2 subunit is an efficacious measure of disease control. However, after decades of efforts, it is still hard to eliminate CSF from endemically affected regions and reemerging areas.

Detection and phylogenetic analysis of porcine circovirus type 3 in Taiwan.

Porcine circovirus type 3 (PCV3) is a newly emerging porcine circovirus that infects pig populations worldwide. In this study, we investigated the prevalence of PCV3 in Taiwan and analyzed the phylogenetic relationships between the Taiwanese PCV3 strains and those from other countries. A total of 463 clinical specimens from sick pigs were collected in 2016-2019 and analyzed for PCV3 by PCR.

Characterization of the monoclonal antibody specific to the ORF72 protein of koi herpesvirus and cellular distribution analysis of the viral protein.

Koi herpesvirus (KHV) is an emerging pathogen of koi and common carp that causes a severe disease and mass mortality of infected fish. The KHV ORF72 protein is an important capsid protein that has been suggested to be a candidate for the development of diagnostic reagents and KHV vaccines. The purpose of this study was to clone and express the KHV ORF72 gene for further preparation of a specific monoclonal antibody (mAb) and to analyse cellular distribution of the viral protein.

The impact of porcine circovirus associated diseases on live attenuated classical swine fever vaccine in field farm applications.

Porcine circovirus associated diseases (PCVADs) are among the most important diseases affecting the worldwide swine industry. Vaccination against porcine circovirus type 2 (PCV2) infection has been utilized for disease control and effectively reduces clinical signs of PCVADs. To evaluate the efficacy of the PCV2 vaccine in field farms, we conducted a trial using conventional pigs immunized with the subunit PCV2 vaccine followed by PCV2 challenge.

N-terminus of Classical swine fever virus strain TD96 glycoprotein E contains a potential heparin-binding domain.

Classical swine fever virus (CSFV) envelope glycoprotein E has been shown to bind to cell surface sulphated-heparin-like glycosaminoglycans (GAGs), which participate in cell attachment of the virus. In this study, the CSFV E gene was codon optimized for expression in the yeast Pichia pastoris. A C-terminally truncated E recombinant protein lacking the previously identified heparin-binding domain (HBD) bound to heparin column, suggesting the presence of another HBD in CSFV E.

Growth properties and vaccine efficacy of recombinant pseudorabies virus defective in glycoprotein E and thymidine kinase genes.

Pseudorabies virus (PRV) is an alphaherpesvirus that causes pseudorabies (PR), an economically important viral disease of pigs. Marker vaccines were widely used in PR prevention and eradication programs. The purpose of this study was to construct a novel recombinant virus with deletions at defined regions in the glycoprotein E (gE) and thymine kinase (TK) genes by homologous recombination.

The preparation of porcine circovirus type 2 (PCV2) virus-like particles using a recombinant pseudorabies virus and its application to vaccine development.

Porcine circovirus type 2 (PCV2) is the primary causative agent of an economically important swine disease, now known as porcine-associated disease (PCVAD). The only structural protein of viral capsid, Cap has become the major target for development of PCV2 subunit vaccines. The purpose of this study is to express Cap of PCV2 using a recombinant pseudorabies virus (PRV) that is gE gene deficient, which is a widely used PRV marker vaccine.

Enhancing expression of the classical swine fever virus glycoprotein E2 in yeast and its application to a blocking ELISA.

Classical swine fever virus (CSFV) infection is a severe swine disease, often causing large economic losses. A Pichia pastoris yeast-expressed CSFV glycoprotein E2 (yE2) has been shown to induce a protective immune response against the virus. To improve the expression level of yE2, the first codon of E2 gene, Arg (CGG), which is the least used in P.

Characterization of the swine U6 promoter for short hairpin RNA expression and its application to inhibition of virus replication.

Expression of short hairpin RNAs (shRNAs) by the RNA polymerase type III U6 promoter is an effective and widely used strategy for RNA interference (RNAi) which is a sequence-specific gene silencing mechanism. The U6 promoters from human, mouse, and swine were cloned, respectively for constructing various shRNA expression vectors. The transcription efficiency of each U6 promoter was analyzed for its activity to drive expression of shRNA targeting enhanced green fluorescent protein (EGFP) mRNA in different mammalian cells.

Characterization of porcine circovirus type 2 (PCV2) capsid particle assembly and its application to virus-like particle vaccine development.

Porcine circovirus type 2 (PCV2) is the primary causative agent of porcine circovirus-associated diseases in pigs. The sole structural capsid protein of PCV2, Cap, consists of major antigenic domains, but little is known about the assembly of capsid particles. The purpose of this study is to produce a large amount of Cap protein using Escherichia coli expression system for further studying the essential sequences contributing to formation of particles.

Yeast expressed classical swine fever E2 subunit vaccine candidate provides complete protection against lethal challenge infection and prevents horizontal virus transmission.

Classical 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 E(rns) and E2 are major targets for eliciting antibodies against CSFV in infected animals. A Pichia pastoris yeast expressed E2 protein (yE2) has been shown to induce a protective immune response against CSFV challenge.

The Porcine Circovirus Type 2 Nonstructural Protein ORF3 Induces Apoptosis in Porcine Peripheral Blood Mononuclear Cells.

Porcine circovirus type 2 (PCV2) is the primary causative agent of porcine circovirus-associated diseases in pigs. To analyze whether the PCV2 nonstructural protein ORF3 is able to induce apoptosis in nature target cells, transient expression of ORF3 in porcine peripheral blood mononuclear cells (PBMC) was performed, and apoptosis was confirmed by terminal dexoynucleotidyl transferase (TdT)-mediated BrdUTP-nick end labeling (TUNEL) assay. The apoptotic responses induced by the full length or the C-terminal half of ORF3 were significantly higher (p < 0.

Characterization of the monoclonal antibody against classical swine fever virus glycoprotein E(rns) and its application to an indirect sandwich ELISA.

Classical swine fever virus (CSFV) E(rns) is an envelope glycoprotein possessing RNase activity. The E(rns)-based enzyme-linked immunosorbent assay (ELISA) has been considered a discriminating diagnostic test for differentiating infected from vaccinated animals. The purpose of this study was to produce a specific monoclonal antibody (MAb) to E(rns) for further developing an indirect sandwich ELISA.

Mechanisms underlying Actinobacillus pleuropneumoniae exotoxin ApxI induced expression of IL-1β, IL-8 and TNF-α in porcine alveolar macrophages.

Actinobacillus pleuropneumoniae (A. pleuropneumoniae) causes fibrino-hemorrhagic necrotizing pleuropneumonia in pigs. Production of proinflammatory mediators in the lungs is an important feature of A.

Expression and immunological studies of classical swine fever virus glycoprotein E2 in the bi-cistronic baculovirus/larvae expression system.

To develop an economical, easy technique for producing recombinant E2 glycoprotein (rE2) of classical swine fever virus (CSFV) as a candidate immunogen, a bi-cistronic baculovirus/larvae expression vector was constructed using p10 promoter, an internal ribosome entry site, and the gfp gene. Trichoplusia ni larvae were successfully infected with the occluded recombinant baculovirus via feed, and the characteristics of rE2 were confirmed by immunoblot and glycosylation stain. rE2 at a concentration of 0.

Mutations in the Salmonella enterica serovar Choleraesuis cAMP-receptor protein gene lead to functional defects in the SPI-1 Type III secretion system.

Salmonella enterica serovar Choleraesuis (Salmonella Choleraesuis) causes a lethal systemic infection (salmonellosis) in swine. Live attenuated Salmonella Choleraesuis vaccines are effective in preventing the disease, and isolates of Salmonella Choleraesuis with mutations in the cAMP-receptor protein (CRP) gene (Salmonella Choleraesuis Deltacrp) are the most widely used, although the basis of the attenuation remains unclear. The objective of this study was to determine if the attenuated phenotype of Salmonella Choleraesuis Deltacrp was due to alterations in susceptibility to gastrointestinal factors such as pH and bile salts, ability to colonize or invade the intestine, or cytotoxicity for macrophages.

Yeast-expressed classical swine fever virus glycoprotein E2 induces a protective immune response.

Classical swine fever (CSF) is an economically important swine disease worldwide. The glycoprotein E2 of classical swine fever virus (CSFV) is a viral antigen that can induce a protective immune response against CSF. A recombinant E2 protein was constructed using the yeast Pichia pastoris expression system and evaluated for its vaccine efficacy.

Efficacy of a novel Pasteurella multocida vaccine against progressive atrophic rhinitis of swine.

The efficacy of a novel vaccine composed of three short recombinant subunit Pasteurella multocida toxin (PMT) proteins in combination with a bi-valent P. multocida whole-cell bacterin (rsPMT-PM) was evaluated in field studies for prevention and control of progressive atrophic rhinitis (PAR) of swine at 15 conventional farrow-to-finish farms. Experimental piglets that were immunized twice with the rsPMT-PM vaccine developed detectable titers of neutralizing antibodies (greater than 1:8) that prevented the growth retardation and pathological lesions typically observed following challenge with authentic PMT.

The N-terminus of porcine circovirus type 2 replication protein is required for nuclear localization and ori binding activities.

Porcine circovirus type 2 possesses a circular, single-stranded DNA genome that requires the replication protein (Rep) for virus replication. To characterize the DNA binding potential and the significant region that confers the nuclear localization of the Rep protein, the defined coding regions of rep gene were cloned and expressed. All of the recombinant proteins except for the N-terminal 110 residues deletion mutant could bind to the double-stranded minimal binding site of replication origin (ori).

Expression of the porcine circovirus type 2 capsid protein subunits and application to an indirect ELISA.

Porcine circovirus type 2 (PCV2) is considered to be associated with post-weaning multisystemic wasting syndrome (PMWS), which is a newly emerged economically important swine disease. The entire coding region of open reading frame 2 (ORF2), encoding the viral capsid protein (Cap), of PCV2 was cloned and sequenced from the clinical specimen obtained from PMWS-affected piglets. Six recombinant subunits, A-F, spanning the defined regions of Cap were produced by E.