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Frontiers in Microbiology 2023Coinfection of porcine epidemic diarrhea virus (PEDV) and porcine deltacoronavirus (PDCoV) is common in pig farms, but there is currently no effective vaccine to prevent...
Developing a multi-epitope vaccine candidate to combat porcine epidemic diarrhea virus and porcine deltacoronavirus co-infection by employing an immunoinformatics approach.
Coinfection of porcine epidemic diarrhea virus (PEDV) and porcine deltacoronavirus (PDCoV) is common in pig farms, but there is currently no effective vaccine to prevent this co-infection. In this study, we used immunoinformatics tools to design a multi-epitope vaccine against PEDV and PDCoV co-infection. The epitopes were screened through a filtering pipeline comprised of antigenic, immunogenic, toxic, and allergenic properties. A new multi-epitope vaccine named , comprising cytotoxic T lymphocyte-, helper T lymphocyte-, and B cell epitopes, was constructed. To enhance immunogenicity, the TLR2 agonist Pam2Cys and the TLR4 agonist RS09 were added to . Molecular docking and dynamics simulation were performed to reveal the stable interactions between and TLR2 as well as TLR4. Additionally, the immune stimulation prediction indicated that could stimulate T and B lymphocytes to induce a robust immune response. Finally, to ensure the expression of the vaccine protein, the sequence of was optimized and further performed cloning. These studies suggest that has the potential to be a vaccine candidate against PEDV and PDCoV co-infection as well as a new strategy for interrupting the spread of both viruses.
PubMed: 38075906
DOI: 10.3389/fmicb.2023.1295678 -
Virology Feb 2024Porcine deltacoronavirus (PDCoV), a new porcine enteric coronavirus, has seriously endangered the pig breeding industry and caused great economic losses. However, a...
Porcine deltacoronavirus (PDCoV), a new porcine enteric coronavirus, has seriously endangered the pig breeding industry and caused great economic losses. However, a PDCoV vaccine is not commercially available. Therefore, new and efficient PDCoV vaccines must be developed without delay. In this study, we used the ExpiCHO eukaryotic expression system to express and purify the following 3 structural proteins of PDCoV: S, N and M. Subsequently, the level of humoral and cellular immunity induced by the S protein (immunization with the S protein alone) and a protein mixture (immunization with a mixture of S, N and M proteins) were evaluated in mice and piglets, respectively, and the performances of the 2 immunizations in a challenge protection test were assessed in piglets. The results showed that both the S protein and the protein mixture induced the production of high levels of specific IgG antibodies and neutralizing antibodies and effectively neutralized PDCoV-infected LLC-PK cells in vitro. Furthermore, compared with the S protein, the N and M proteins in the protein mixture promoted the expression of CD8 T cells and IFN-γ, induced a stronger cellular immune response, and effectively protected 4/5 of the piglets from PDCoV infection. In conclusion, the results of this study showed that the N and M proteins play important roles in inducing an immunoprotective response. Using N and M antigens as effective antigenic components in the development of PDCoV vaccines in the future will effectively increase the immune efficacy of the vaccines.
Topics: Animals; Swine; Mice; CD8-Positive T-Lymphocytes; Coronavirus; Coronavirus Infections; Vaccines, Subunit; Swine Diseases
PubMed: 38070302
DOI: 10.1016/j.virol.2023.109955 -
Veterinarni Medicina Mar 2023Porcine deltacoronavirus (PDCoV) and porcine sapelovirus (PSV) are two viruses that can cause diarrhoea in pigs and bring great economic loss to the pig industry....
Development and application of a low-priced duplex quantitative PCR assay based on SYBR Green I for the simultaneous detection of porcine deltacoronavirus and porcine sapelovirus.
Porcine deltacoronavirus (PDCoV) and porcine sapelovirus (PSV) are two viruses that can cause diarrhoea in pigs and bring great economic loss to the pig industry. In this research, a duplex real-time quantitative polymerase chain reaction (qPCR) assay based on SYBR Green I was developed to simultaneously detect PDCoV and PSV. No specific melting peaks were found in other porcine diarrhoea-associated viruses, indicating that the method developed in this study had good specificity. The detection limits of PDCoV and PSV were 1.0 × 10 copies μl and 1.0 × 10 copies μl, respectively. The duplex real-time qPCR assay tested two hundred and three (203) intestinal and faecal samples collected from diarrhoeal and asymptomatic pigs. The positive rates of PDCoV and PSV were 20.2% and 23.2%, respectively. The co-infection rate of PDCoV and PSV was 13.8%. To evaluate the accuracy of the developed method, conventional PCR and singular TaqMan real-time qPCR assays for PDCoV/PSV were also used to detect the samples. The results showed that the duplex real-time qPCR assay was consistent with the singular assays, but its sensitivity was higher than conventional PCR methods. This duplex real-time qPCR assay provides a rapid, sensitive and reliable method in a clinic to simultaneously detect PDCoV and PSV.
PubMed: 37981902
DOI: 10.17221/79/2022-VETMED -
Microbiology Spectrum Dec 2023Porcine deltacoronavirus (PDCoV) is a newly emerged enteric virus threatening pig industries worldwide. Our previous work showed that PDCoV enters porcine kidney (PK-15)...
Porcine deltacoronavirus (PDCoV) is a newly emerged enteric virus threatening pig industries worldwide. Our previous work showed that PDCoV enters porcine kidney (PK-15) cells through a caveolae-dependent pathway, but the entry mechanism for PDCoV into swine testicle (ST) cells remains unclear. Mechanisms of virus entry can be different with different virus isolates and cell types. Here, we determined that PDCoV enters ST cells via clathrin-mediated endocytosis. Additionally, we found that PDCoV entry does not require Rab5, Rab7, or Rab11. These findings provide additional understanding of the entry mechanisms of PDCoV and possible antiviral targets.
Topics: Animals; Swine; Endocytosis; Deltacoronavirus; Virus Internalization; Clathrin; Swine Diseases; Coronavirus Infections
PubMed: 37962380
DOI: 10.1128/spectrum.02553-23 -
Viruses Sep 2023Emerging and re-emerging swine coronaviruses (CoVs), including porcine epidemic diarrhea virus (PEDV), porcine deltacoronavirus (PDCoV), and swine acute diarrhea... (Review)
Review
Emerging and re-emerging swine coronaviruses (CoVs), including porcine epidemic diarrhea virus (PEDV), porcine deltacoronavirus (PDCoV), and swine acute diarrhea syndrome-CoV (SADS-CoV), cause severe diarrhea in neonatal piglets, and CoV infection is associated with significant economic losses for the swine industry worldwide. Reverse genetics systems realize the manipulation of RNA virus genome and facilitate the development of new vaccines. Thus far, five reverse genetics approaches have been successfully applied to engineer the swine CoV genome: targeted RNA recombination, in vitro ligation, bacterial artificial chromosome-based ligation, vaccinia virus -based recombination, and yeast-based method. This review summarizes the advantages and limitations of these approaches; it also discusses the latest research progress in terms of their use for virus-related pathogenesis elucidation, vaccine candidate development, antiviral drug screening, and virus replication mechanism determination.
Topics: Animals; Swine; Coronavirus; Reverse Genetics; Coronavirus Infections; Porcine epidemic diarrhea virus; RNA; Diarrhea; Swine Diseases
PubMed: 37896780
DOI: 10.3390/v15102003 -
Journal of Virology Nov 2023As a member of the δ-coronavirus family, porcine deltacoronavirus (PDCoV) is a vital reason for diarrhea in piglets, which can contribute to high morbidity and...
As a member of the δ-coronavirus family, porcine deltacoronavirus (PDCoV) is a vital reason for diarrhea in piglets, which can contribute to high morbidity and mortality rates. Initially identified in Hong Kong in 2012, the virus has rapidly spread worldwide. During PDCoV infection, the virus employs evasion mechanisms to evade host surveillance, while the host mounts corresponding responses to impede viral replication. Our research has revealed that PDCoV infection down-regulates the expression of PGAM5 to promote virus replication. In contrast, PGAM5 degrades PDCoV N through autophagy by interacting with the cargo receptor P62 and the E3 ubiquitination ligase STUB1. Additionally, PGAM5 interacts with MyD88 and TRAF3 to activate the IFN signal pathway, resulting in the inhibition of viral replication.
Topics: Animals; Coronavirus Infections; Interferon Type I; Signal Transduction; Swine; Swine Diseases; Ubiquitin-Protein Ligases; Virus Replication; Coronavirus Nucleocapsid Proteins; Deltacoronavirus; Phosphoprotein Phosphatases; Mitochondrial Proteins; Down-Regulation; Immune Evasion; RNA-Binding Proteins; Proteolysis
PubMed: 37882521
DOI: 10.1128/jvi.01470-23 -
Journal of Virology Nov 2023As an emerging porcine enteropathogenic coronavirus that has the potential to infect humans, porcine deltacoronavirus (PDCoV) is receiving increasing attention. However,...
As an emerging porcine enteropathogenic coronavirus that has the potential to infect humans, porcine deltacoronavirus (PDCoV) is receiving increasing attention. However, no effective commercially available vaccines against this virus are available. In this work, we designed a spike (S) protein and receptor-binding domain (RBD) trimer as a candidate PDCoV subunit vaccine. We demonstrated that S protein induced more robust humoral and cellular immune responses than the RBD trimer in mice. Furthermore, the protective efficacy of the S protein was compared with that of inactivated PDCoV vaccines in piglets and sows. Of note, the immunized piglets and suckling pig showed a high level of NAbs and were associated with reduced virus shedding and mild diarrhea, and the high level of NAbs was maintained for at least 4 months. Importantly, we demonstrated that S protein-based subunit vaccines conferred significant protection against PDCoV infection.
Topics: Animals; Female; Humans; Mice; Coronavirus; Coronavirus Infections; Deltacoronavirus; Swine; Swine Diseases; Vaccines, Subunit
PubMed: 37846983
DOI: 10.1128/jvi.00958-23 -
Journal of Virology Oct 2023Retrograde transport has been reported to be closely associated with normal cellular biological processes and viral replication. As an emerging enteropathogenic...
Retrograde transport has been reported to be closely associated with normal cellular biological processes and viral replication. As an emerging enteropathogenic coronavirus with zoonotic potential, porcine deltacoronavirus (PDCoV) has attracted considerable attention. However, whether retrograde transport is associated with PDCoV infection remains unclear. Our present study demonstrates that retromer protein VPS35 acts as a critical host factor that is required for PDCoV infection. Mechanically, VPS35 interacts with PDCoV NS6, mediating the retrograde transport of NS6 from endosomes to the Golgi and preventing it from lysosomal degradation. Recombinant PDCoVs with an NS6 deletion display resistance to VPS35 deficiency. Our work reveals a novel evasion mechanism of PDCoV that involves the manipulation of the retrograde transport pathway by VPS35, providing new insight into the mechanism of PDCoV infection.
Topics: Animals; Coronavirus; Coronavirus Infections; Deltacoronavirus; Swine; Swine Diseases; Virus Replication; Viral Regulatory and Accessory Proteins; Vesicular Transport Proteins
PubMed: 37815351
DOI: 10.1128/jvi.00957-23 -
PLoS Pathogens Oct 2023Coronaviruses (CoVs) are a family of the largest RNA viruses that typically cause respiratory, enteric, and hepatic diseases in animals and humans, imposing great...
Coronaviruses (CoVs) are a family of the largest RNA viruses that typically cause respiratory, enteric, and hepatic diseases in animals and humans, imposing great threats to the public safety and animal health. Porcine deltacoronavirus (PDCoV), a newly emerging enteropathogenic coronavirus, causes severe diarrhea in suckling piglets all over the world and poses potential risks of cross-species transmission. Here, we use PDCoV as a model of CoVs to illustrate the reciprocal regulation between CoVs infection and host antiviral responses. In this study, downregulation of DNA polymerase delta interacting protein 3 (POLDIP3) was confirmed in PDCoV infected IPEC-J2 cells by isobaric tags for relative and absolute quantification (iTRAQ) and Western blotting analysis. Overexpression of POLDIP3 inhibits PDCoV infection, whereas POLDIP3 knockout (POLDIP3-/-) by CRISPR-Cas9 editing significantly promotes PDCoV infection, indicating POLDIP3 as a novel antiviral regulator against PDCoV infection. Surprisingly, an antagonistic strategy was revealed that PDCoV encoded nonstructural protein 5 (nsp5) was responsible for POLDIP3 reduction via its 3C-like protease cleavage of POLDIP3 at the glutamine acid 176 (Q176), facilitating PDCoV infection due to the loss of antiviral effects of the cleaved fragments. Consistent with the obtained data in IPEC-J2 cell model in vitro, POLDIP3 reduction by cleavage was also corroborated in PDCoV infected-SPF piglets in vivo. Collectively, we unveiled a new antagonistic strategy evolved by PDCoV to counteract antiviral innate immunity by nsp5-mediated POLDIP3 cleavage, eventually ensuring productive virus replication. Importantly, we further demonstrated that nsp5s from PEDV and TGEV harbor the conserved function to cleave porcine POLDIP3 at the Q176 to despair POLDIP3-mediated antiviral effects. In addition, nsp5 from SARS-CoV-2 also cleaves human POLDIP3. Therefore, we speculate that coronaviruses employ similar POLDIP3 cleavage mechanisms mediated by nsp5 to antagonize the host antiviral responses to sustain efficient virus infection.
Topics: Animals; Humans; Swine; Immunity, Innate; Virus Replication; Antiviral Agents; Coronavirus Infections; Swine Diseases; RNA-Binding Proteins
PubMed: 37801439
DOI: 10.1371/journal.ppat.1011702 -
Vaccine Oct 2023Porcine deltacoronavirus (PDCoV) is a novel swine enteropathogenic coronavirus that causes severe watery diarrhea, vomiting, dehydration and high mortality in piglets,...
Porcine deltacoronavirus (PDCoV) is a novel swine enteropathogenic coronavirus that causes severe watery diarrhea, vomiting, dehydration and high mortality in piglets, resulting in significant economic losses by the global pig industry. Recently, PDCoV has also shown the potential for cross-species transmission. However, there are currently few vaccine studies and no commercially available vaccines for PDCoV. Hence, here, two novel human adenovirus 5 (Ad5)-vectored vaccines expressing codon-optimized forms of the PDCoV spike (S) glycoprotein (Ad-PD-tPA-Sopt) and S1 glycoprotein (Ad-PD-oriSIP-S1opt) were constructed, and their effects were evaluated via intramuscular (IM) injection in BALB/c mice with different doses and times. Both vaccines elicited robust humoral and cellular immune responses; moreover, Ad-PD-tPA-Sopt-vaccinated mice after two IM injections with 10 infectious units (IFU)/mouse had significantly higher anti-PDCoV-specific neutralizing antibody titers. In contrast, the mice immunized with Ad-PD-tPA-Sopt via oral gavage (OG) did not generate robust systemic and mucosal immunity. Thus, IM Ad-PD-tPA-Sopt administration is a promising strategy against PDCoV and provides useful information for future animal vaccine development.
Topics: Humans; Animals; Swine; Mice; Adenovirus Vaccines; Vaccines; Glycoproteins; Immunity, Cellular; Adenoviridae; Swine Diseases; Coronavirus Infections
PubMed: 37777448
DOI: 10.1016/j.vaccine.2023.09.053