scholarly journals Successive Passage In Vitro Led to Lower Virulence and Higher Titer of A Variant Porcine Epidemic Diarrhea Virus

Viruses ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 391 ◽  
Author(s):  
Pengwei Zhao ◽  
Song Wang ◽  
Zhi Chen ◽  
Jiang Yu ◽  
Rongzhi Tang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Porcine Epidemic Diarrhea Virus ◽  
Vero Cells ◽  
Economic Losses ◽  
Diarrhea Virus ◽  
S Gene ◽  
Successive Passage ◽  
Porcine Epidemic Diarrhea

A highly virulent porcine epidemic diarrhea virus (PEDV) appeared in China and spread rapidly to neighbor countries, which have led to great economic losses to the pig industry. In the present study, we isolated a PEDV using Vero cells and serially propagated 100 passages. PEDV SDSX16 was characterized in vitro and in vivo. The viral titers increased to 107.6 TCID50/mL (100th) by serial passages. The spike (S) gene and the whole gene of the SDSX16 virus was fully sequenced to assess the genetic stability and relatedness to previously identified PEDV. Along with successive passage in vitro, there were 18 nucleotides (nt) deletion occurred in the spike (S) gene resulting in a deletion of six amino acids when the SDSX16 strain was passaged to the 64th generation, and this deletion was stable until the P100. However, the ORF1a/b, M, N, E, and ORF3 genes had only a few point mutations in amino acids and no deletions. According to growth kinetics experiments, the SDSX16 deletion strain significantly enhanced its replication in Vero cells since it was passaged to the 64th generation. The animal studies showed that PEDV SDSX16-P10 caused more severe diarrhea and vomiting, fecal shedding, and acute atrophic enteritis than SDSX16-P75, indicating that SDSX16-P10 is enteropathogenic in the natural host, and the pathogenicity of SDSX16 decreased with successive passage in vitro. However, SDSX16-P10 was found to cause lower levels of cytokine expression than SDSX16-P75 using real-time PCR and flow cytometry, such as IL1β, IL6, IFN-β, TNF-α, indicating that SDSX16-P10 might inhibit the expression of cytokines. Our data indicated that successive passage in vitro resulted in virulent attenuation in vivo of the PEDV variant strain SDSX16.

scholarly journals Caerin1.1 Suppresses the Growth of Porcine Epidemic Diarrhea Virus In Vitro via Direct Binding to the Virus

Viruses ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 507 ◽  
Author(s):  
Nan Guo ◽  
Bingzhou Zhang ◽  
Han Hu ◽  
Shiyi Ye ◽  
Fangzhou Chen ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Porcine Epidemic Diarrhea Virus ◽  
Antiviral Drug ◽  
Vero Cells ◽  
Economic Losses ◽  
Diarrhea Virus ◽  
Direct Binding ◽  
Porcine Epidemic Diarrhea ◽  
And Control

Porcine epidemic diarrhea (PED) has re-emerged in recent years and has already caused huge economic losses to the porcine industry all over the world. Therefore, it is urgent for us to find out efficient ways to prevent and control this disease. In this study, the antiviral activity of a cationic amphibian antimicrobial peptide Caerin1.1 against porcine epidemic diarrhea virus (PEDV) was evaluated by an in vitro system using Vero cells. We found that even at a very low concentration, Caerin1.1 has the ability to destroy the integrity of the virus particles to block the release of the viruses, resulting in a considerable decrease in PEDV infections. In addition, Caerin1.1 showed powerful antiviral activity without interfering with the binding progress between PEDV and the receptor of the cells, therefore, it could be used as a potential antiviral drug or as a microbicide compound for prevention and control of PEDV.

scholarly journals Porcine Epidemic Diarrhea Virus (PEDV) ORF3 Enhances Viral Proliferation by Inhibiting Apoptosis of Infected Cells

Viruses ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 214 ◽  
Author(s):  
Fusheng Si ◽  
Xiaoxia Hu ◽  
Chenyang Wang ◽  
Bingqing Chen ◽  
Ruiyang Wang ◽  
...  
Keyword(s):  
Porcine Epidemic Diarrhea Virus ◽  
Underlying Mechanism ◽  
Vero Cells ◽  
Orf3 Gene ◽  
Accessory Gene ◽  
Orf3 Protein ◽  
Diarrhea Virus ◽  
Viral Virulence ◽  
Porcine Epidemic Diarrhea

The genomes of coronaviruses carry accessory genes known to be associated with viral virulence. The single accessory gene of porcine epidemic diarrhea virus (PEDV), ORF3, is dispensable for virus replication in vitro, while viral mutants carrying ORF3 truncations exhibit an attenuated phenotype of which the underlying mechanism is unknown. Here, we studied the effect of ORF3 deletion on the proliferation of PEDV in Vero cells. To this end, four recombinant porcine epidemic diarrhea viruses (PEDVs) were rescued using targeted RNA recombination, three carrying the full-length ORF3 gene from different PEDV strains, and one from which the ORF3 gene had been deleted entirely. Our results showed that PEDVs with intact or naturally truncated ORF3 replicated to significantly higher titers than PEDV without an ORF3. Further characterization revealed that the extent of apoptosis induced by PEDV infection was significantly lower with the viruses carrying an intact or C-terminally truncated ORF3 than with the virus lacking ORF3, indicating that the ORF3 protein as well as its truncated form interfered with the apoptosis process. Collectively, we conclude that PEDV ORF3 protein promotes virus proliferation by inhibiting cell apoptosis caused by virus infection. Our findings provide important insight into the role of ORF3 protein in the pathogenicity of PEDV.

scholarly journals Investigation of the Role of the Spike Protein in Reversing the Virulence of the Highly Virulent Taiwan Porcine Epidemic Diarrhea Virus Pintung 52 Strains and Its Attenuated Counterpart

Viruses ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 41 ◽  
Author(s):  
Chi-Fei Kao ◽  
Hui-Wen Chang
Keyword(s):  
Mortality Rate ◽  
Porcine Epidemic Diarrhea Virus ◽  
Rational Design ◽  
Economic Losses ◽  
Diarrhea Virus ◽  
Viral Shedding ◽  
S Gene ◽  
Porcine Epidemic Diarrhea ◽  
Highly Virulent

Porcine epidemic diarrhea virus (PEDV) has continuously caused severe economic losses to the global swine industries; however, no successful vaccine against PEDV has been developed. In this study, we generated four autologous recombinant viruses, including the highly virulent iPEDVPT-P5, attenuated iPEDVPT-P96, and two chimeric viruses (iPEDVPT-P5-96S and iPEDVPT-P96-5S) with the reciprocally exchanged spike (S) gene, to study the role of the S gene in PEDV pathogenesis. A deeper understanding of PEDV attenuation will aid in the rational design of a live attenuated vaccine (LAV) using reverse genetics system. Our results showed that replacing the S gene from the highly virulent iPEDVPT-P5 led to complete restoration of virulence of the attenuated iPEDVPT-P96, with nearly identical viral shedding, diarrhea pattern, and mortality rate as the parental iPEDVPT-P5. In contrast, substitution of the S gene with that from the attenuated iPEDVPT-P96 resulted in partial attenuation of iPEDVPT-P5, exhibiting similar viral shedding and diarrhea patterns as the parental iPEDVPT-P96 with slightly severe histological lesions and higher mortality rate. Collectively, our data confirmed that the attenuation of the PEDVPT-P96 virus is primarily attributed to mutations in the S gene. However, mutation in S gene alone could not fully attenuate the virulence of iPEDVPT-P5. Gene (s) other than S gene might also play a role in determining virulence.

scholarly journals Characterization and pathogenicity of Vero cell-attenuated porcine epidemic diarrhea virus CT strain

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Yu Wu ◽  
Wei Li ◽  
Qingfeng Zhou ◽  
Qunhui Li ◽  
Zhichao Xu ◽  
...  
Keyword(s):  
Porcine Epidemic Diarrhea Virus ◽  
Clinical Symptoms ◽  
Vero Cells ◽  
Economic Losses ◽  
Protective Effects ◽  
Diarrhea Virus ◽  
Cytopathic Effects ◽  
Porcine Epidemic Diarrhea ◽  
Piglet Survival

Abstract Background Porcine epidemic diarrhea virus (PEDV) has caused enormous economic losses to the global pig industry. Currently available PEDV vaccine strains have limited protective effects against PEDV variant strains. Methods In this study, the highly virulent epidemic virus strain CT was serially passaged in Vero cells for up to 120 generations (P120). Characterization of the different passages revealed that compared with P10 and P64, P120 had a higher viral titer and more obvious cytopathic effects, thereby demonstrating better cell adaptability. Results Pathogenicity experiments using P120 in piglets revealed significant reductions in clinical symptoms, histopathological lesions, and intestinal PEDV antigen distribution; the piglet survival rate in the P120 group was 100%. Furthermore, whole-genome sequencing identified 13 amino acid changes in P120, which might be responsible for the attenuated virulence of P120. Conclusions Thus, an attenuated strain was obtained via cell passaging and that this strain could be used in preparing attenuated vaccines.

scholarly journals Porcine Intestinal Enteroids: a New Model for Studying Enteric Coronavirus Porcine Epidemic Diarrhea Virus Infection and the Host Innate Response

2018 ◽  
Vol 93 (5) ◽  
Author(s):  
Liang Li ◽  
Fang Fu ◽  
Shanshan Guo ◽  
Hongfeng Wang ◽  
Xijun He ◽  
...  
Keyword(s):  
Stem Cells ◽  
Intestinal Epithelium ◽  
Porcine Epidemic Diarrhea Virus ◽  
Enteric Viruses ◽  
Antiviral Response ◽  
Diarrhea Virus ◽  
Porcine Epidemic Diarrhea ◽  
Ifn Lambda

ABSTRACTPorcine epidemic diarrhea virus (PEDV), a member of the group of alphacoronaviruses, is the pathogen of a highly contagious gastrointestinal swine disease. The elucidation of the events associated with the intestinal epithelial response to PEDV infection has been limited by the absence of goodin vitroporcine intestinal models that recapitulate the multicellular complexity of the gastrointestinal tract. Here, we generated swine enteroids from the intestinal crypt stem cells of the duodenum, jejunum, or ileum and found that the generated enteroids are able to satisfactorily recapitulate the complicated intestinal epitheliumin vivoand are susceptible to infection by PEDV. PEDV infected multiple types of cells, including enterocytes, stem cells, and goblet cells, and exhibited segmental infection discrepancies compared with ileal enteroids and colonoids, and this finding was verifiedin vivo. Moreover, the clinical isolate PEDV-JMS propagated better in ileal enteroids than the cell-adapted isolate PEDV-CV777, and PEDV infection suppressed interferon (IFN) production early during the infection course. IFN lambda elicited a potent antiviral response and inhibited PEDV in enteroids more efficiently than IFN alpha (IFN-α). Therefore, swine enteroids provide a novelin vitromodel for exploring the pathogenesis of PEDV and for thein vitrostudy of the interplay between a host and a variety of swine enteric viruses.IMPORTANCEPEDV is a highly contagious enteric coronavirus that causes significant economic losses, and the lack of a goodin vitromodel system is a major roadblock to an in-depth understanding of PEDV pathogenesis. Here, we generated a porcine intestinal enteroid model for PEDV infection. Utilizing porcine intestinal enteroids, we demonstrated that PEDV infects multiple lineages of the intestinal epithelium and preferably infects ileal enteroids over colonoids and that enteroids prefer to respond to IFN lambda 1 over IFN-α. These events recapitulate the events that occurin vivo. This study constitutes the first use of a primary intestinal enteroid model to investigate the susceptibility of porcine enteroids to PEDV and to determine the antiviral response following infection. Our study provides important insights into the events associated with PEDV infection of the porcine intestine and provides a valuablein vitromodel for studying not only PEDV but also other swine enteric viruses.

scholarly journals Genome Sequences of Porcine Epidemic Diarrhea Virus: In Vivo and In Vitro Phenotypes

2014 ◽  
Vol 2 (3) ◽  
Author(s):  
P. K. Lawrence ◽  
E. Bumgardner ◽  
R. F. Bey ◽  
D. Stine ◽  
R. E. Bumgarner
Keyword(s):  
Porcine Epidemic Diarrhea Virus ◽  
Genome Sequences ◽  
Diarrhea Virus ◽  
Porcine Epidemic Diarrhea

scholarly journals Molecular Characteristics and Pathogenicity of Porcine Epidemic Diarrhea Virus Isolated in Some Areas of China in 2015–2018

2020 ◽  
Vol 7 ◽  
Author(s):  
Linyang Yu ◽  
Yanling Liu ◽  
Shuangyun Wang ◽  
Leyi Zhang ◽  
Pengshuai Liang ◽  
...  
Keyword(s):  
Porcine Epidemic Diarrhea Virus ◽  
Vero Cells ◽  
Economic Losses ◽  
Molecular Characteristics ◽  
Phylogenetic Tree Analysis ◽  
Genetic Characteristics ◽  
Diarrhea Virus ◽  
Severe Diarrhea ◽  
Positive Rate ◽  
Porcine Epidemic Diarrhea

Since 2010, Porcine epidemic diarrhea virus (PEDV) has caused severe diarrhea disease in piglets in China, resulting in large economic losses. To understand the genetic characteristics of the PEDV strains that circulated in some provinces of China between 2015 and 2018, 375 samples of feces and small intestine were collected from pigs and tested. One hundred seventy-seven samples tested positive and the PEDV-positive rate was 47.20%. A phylogenetic tree analysis based on the entire S gene showed that these strains clustered into four subgroups, GI-a, GI-b, GII-a, and GII-b, and that the GII-b strains have become dominant in recent years. Compared with previous strains, these strains have multiple variations in the SP and S1-NTD domains and in the neutralizing epitopes of the S protein. We also successfully isolated and identified a new virulent GII-b strain, GDgh16, which is well-adapted to Vero cells and caused a high mortality rate in piglets in challenge experiments. Our study clarifies the genetic characteristics of the prevalent PEDV strains in parts of China, and suggests that the development of effective novel vaccines is both necessary and urgent.

scholarly journals Tomatidine inhibits porcine epidemic diarrhea virus replication by targeting 3CL protease

2020 ◽  
Vol 51 (1) ◽  
Author(s):  
Pengcheng Wang ◽  
Juan Bai ◽  
Xuewei Liu ◽  
Mi Wang ◽  
Xianwei Wang ◽  
...  
Keyword(s):  
Porcine Epidemic Diarrhea Virus ◽  
Economic Losses ◽  
Titration Calorimetry ◽  
Respiratory Syndrome Virus ◽  
Transmissible Gastroenteritis Virus ◽  
Diarrhea Virus ◽  
Infected Cells ◽  
Porcine Epidemic Diarrhea ◽  
3Cl Protease

Abstract Porcine epidemic diarrhea virus (PEDV) causes lethal diarrhea in suckling piglets, leading to severe economic losses worldwide. There is an urgent need to find new therapeutic methods to prevent and control PEDV. Not only is there a shortage of commercial anti-PEDV drugs, but available commercial vaccines fail to protect against highly virulent PEDV variants. We screened an FDA-approved library of 911 natural products and found that tomatidine, a steroidal alkaloid extracted from the skin and leaves of tomatoes, demonstrates significant inhibition of PEDV replication in Vero and IPEC-J2 cells in vitro. Molecular docking and molecular dynamics analysis predicted interactions between tomatidine and the active pocket of PEDV 3CL protease, which were confirmed by fluorescence spectroscopy and isothermal titration calorimetry (ITC). The inhibiting effect of tomatidine on 3CL protease was determined using cleavage visualization and FRET assay. Tomatidine-mediated blocking of 3CL protease activity in PEDV-infected cells was examined by western blot detection of the viral polyprotein in PEDV-infected cells. It indicates that tomatidine inhibits PEDV replication mainly by targeting 3CL protease. In addition, tomatidine also has antiviral activity against transmissible gastroenteritis virus (TGEV), porcine reproductive and respiratory syndrome virus (PRRSV), encephalo myocarditis virus (EMCV) and seneca virus A (SVA) in vitro. These results may be helpful in developing a new prophylactic and therapeutic strategy against PEDV and other swine disease infections.

scholarly journals In Vitro Antiviral Activities of Salinomycin on Porcine Epidemic Diarrhea Virus

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 580
Author(s):  
Chen Yuan ◽  
Xintong Huang ◽  
Ruiyu Zhai ◽  
Yichao Ma ◽  
Anyuan Xu ◽  
...  
Keyword(s):  
Porcine Epidemic Diarrhea Virus ◽  
Mapk Pathway ◽  
Vero Cells ◽  
Dependent Manner ◽  
Diarrhea Virus ◽  
Pathway Activation ◽  
P38mapk Signaling ◽  
Porcine Epidemic Diarrhea ◽  
Post Entry

Porcine epidemic diarrhea virus (PEDV), an enteropathogenic coronavirus, has catastrophic impacts on the global pig industry. Owing to the lack of effective vaccines and specific therapeutic options for PEDV, it is pertinent to develop new and available antivirals. This study identified, for the first time, a salinomycin that actively inhibited PEDV replication in Vero cells in a dose-dependent manner. Furthermore, salinomycin significantly inhibited PEDV infection by suppressing the entry and post-entry of PEDV in Vero cells. It did not directly interact with or inactivate PEDV particles, but it significantly ameliorated the activation of Erk1/2, JNK and p38MAPK signaling pathways that are associated with PEDV infection. This implied that salinomycin inhibits PEDV replication by altering MAPK pathway activation. Notably, the PEDV induced increase in reactive oxidative species (ROS) was not decreased, indicating that salinomycin suppresses PEDV replication through a pathway that is an independent pathway of viral-induced ROS. Therefore, salinomycin is a potential drug that can be used for treating PEDV infection.

scholarly journals The S Gene Is Necessary but Not Sufficient for the Virulence of Porcine Epidemic Diarrhea Virus Novel Variant Strain BJ2011C

2018 ◽  
Vol 92 (13) ◽  
Author(s):  
Di Wang ◽  
Xinna Ge ◽  
Dongjie Chen ◽  
Jie Li ◽  
Yueqi Cai ◽  
...  
Keyword(s):  
Porcine Epidemic Diarrhea Virus ◽  
Vaccine Development ◽  
Economic Losses ◽  
Avirulent Strain ◽  
Diarrhea Virus ◽  
Severe Diarrhea ◽  
S Gene ◽  
Viral Virulence ◽  
Porcine Epidemic Diarrhea ◽  
Highly Virulent

ABSTRACT The recently emerged highly virulent variants of porcine epidemic diarrhea virus (PEDV) have caused colossal economic losses to the worldwide swine industry. In this study, we investigated the viral virulence determinants by constructing a series of chimeric mutants between the highly virulent strain BJ2011C and the avirulent strain CHM2013. When tested in the 2-day-old piglet model, wild-type (WT) BJ2011C caused severe diarrhea and death of the piglets within 72 h. In contrast, its chimeric derivative carrying the S gene from CHM2013 (BJ2011C-S CHM ) was avirulent to the piglets. Moreover, reciprocal substitution of the BJ2011C S gene (CHM2013-S BJ ) did not enable CHM2013 to gain any virulence. However, when the whole structural protein-coding region of BJ2011C (CHM2013-SP BJ ) was swapped, CHM2013 started to gain the ability to efficiently colonize the intestinal tract and caused diarrhea in piglets. A further gain of virulence required additional acquisition of the 3′ untranslated region (UTR) of BJ2011C, and the resultant virus (CHM2013-SP + 3UTR BJ ) caused more severe diarrhea and death of piglets. Together, our findings suggest that the virulence of PEDV epidemic strains is a multigenic event and that the S gene is only one of the necessary determinants. IMPORTANCE The recently emerged highly virulent PEDV variants are the major cause of the global porcine epidemic diarrhea (PED) pandemic. The S gene of the variants undergoes remarkable variations and has been thought to be the virulence determinant for the enhanced pathogenesis. Our studies here showed that the S gene is only part of the story and that full virulence requires cooperation from other genes. Our findings provide insight into the pathogenic mechanism of the highly virulent PEDV variants and have implications for future vaccine development.

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