-
Viruses Mar 2024Coronaviruses (CoVs) are RNA viruses capable of infecting a wide range of hosts, including mammals and birds, and have caused significant epidemics such as the ongoing...
Coronaviruses (CoVs) are RNA viruses capable of infecting a wide range of hosts, including mammals and birds, and have caused significant epidemics such as the ongoing COVID-19 pandemic. Bats, the second most diverse mammalian order, are hosts for various CoVs due to their unique immune responses and ecological traits. This study investigates CoV prevalence in crevice- and tree-dwelling bats in Portugal, a country with limited prior research on bat CoVs. Using nested RT-PCR and sequencing, we screened 87 stool samples from bats, identifying one sample (1.15%) that was positive for , belonging to . Phylogenetic analysis revealed close genetic relationships with strains from the same bat species in Europe. The low prevalence suggests habitat-specific differences in viral transmission, with cave-dwelling bats exhibiting higher CoV prevalence due to population density and behaviour. These findings underscore the necessity for sustained surveillance efforts aimed at comprehending CoV dynamics within bat populations, especially concerning the risk of spillover events and viral evolution. Vital to this understanding is the monitoring of bat migration patterns, which serves as a crucial tool for elucidating CoV ecology and epidemiology. Such efforts are essential for ongoing research endeavours aimed at mitigating the potential for future zoonotic disease outbreaks.
Topics: Animals; Humans; Alphacoronavirus; Chiroptera; Phylogeny; Portugal; Pandemics; Coronavirus Infections; Genome, Viral
PubMed: 38543799
DOI: 10.3390/v16030434 -
Journal of Virology Sep 2023Porcine epidemic diarrhea virus (PEDV) leads to enormous economic losses for the pork industry. However, the commercial vaccines failed to fully protect against the...
Porcine epidemic diarrhea virus (PEDV) leads to enormous economic losses for the pork industry. However, the commercial vaccines failed to fully protect against the epidemic strains. Previously, the rCH/SX/2016-S strain with the entire E protein and the rCH/SX/2015 strain with the deletion of 7-amino-acid (7-aa) at positions 23-29 in E protein were constructed and rescued. The pathogenicity assay indicated that rCH/SX/2015 is an attenuated strain, but rCH/SX/2016-S belongs to the virulent strains. Then, the recombination PEDV (rPEDV-E)strain with a 7-aa deletion in the E protein was generated, using the highly virulent rCH/SX/2016-S strain (rPEDV-E) as the backbone. Compared with the rPEDV-E strain, the release and infectivity of the rPEDV-E strain were significantly reduced , but stronger interferon (IFN) responses were triggered both and . The pathogenicity assay showed that the parental strain resulted in severe diarrhea (100%) and death (100%) in all piglets. Compared with the parental strain group, rPEDV-E caused lower mortality (33%) and diminished fecal PEDV RNA shedding. At 21 days, all surviving pigs were challenged orally with rPEDV-E. No pigs died in the two groups. Compared with the mock group, significantly delayed and milder diarrhea and reduced fecal PEDV RNA shedding were detected in the rPEDV-E group. In conclusion, the deletion of a 7-aa fragment in the E protein (E) attenuated PEDV but retained its immunogenicity, which can offer new ideas for the design of live attenuated vaccines and provide new insights into the attenuated mechanism of PEDV. IMPORTANCE Porcine epidemic diarrhea virus (PEDV) causes high mortality in neonatal piglets and remains a large challenge to the pork industry. Unfortunately, no safe and effective vaccines are available yet. The pathogenesis and molecular basis of the attenuation of PEDV remain unclear, which seriously hinders the development of PEDV vaccines. This study found that the rPEDV carrying E mutation in the E protein induced significantly higher IFN responses than the parental virus, partially attenuated, and remained immunogenic in piglets. For the first time, PEDV E was verified as an IFN antagonist in the infection context and identified as a virulence factor of PEDV. Our data also suggested that E mutation can be a good target for the development of live attenuated vaccines for PEDV and also provide new perspectives for the attenuated mechanism of PEDV.
Topics: Animals; Coronavirus Infections; Interferons; Porcine epidemic diarrhea virus; RNA; Swine; Swine Diseases; Vaccines, Attenuated; Sequence Deletion; Viral Envelope Proteins
PubMed: 37681956
DOI: 10.1128/jvi.00847-23 -
Frontiers in Immunology 2023Interferon regulatory factor 8 () is a key regulator of innate immune receptor signaling that resists pathogen invasion by regulating cell growth and differentiation....
Interferon regulatory factor 8 () is a key regulator of innate immune receptor signaling that resists pathogen invasion by regulating cell growth and differentiation. Porcine epidemic diarrhea virus (PEDV) targets the intestine and damages the mucosal barrier. However, whether regulates PEDV replication remains unclear. We revealed that PEDV infection activated expression. Moreover, deletion drastically promoted PEDV replication and invasion, increasing the virus copies and titers. Hypomethylation enrichment of activating protein (AP)-2α was significantly negatively correlated with high expression, and AP-2α directly targeted the promoter to regulate PEDV replication. Furthermore, overexpression decreased the cellular reactive oxygen species levels and mitochondrial membrane potential and increased the antioxidant enzyme activities to alleviate PEDV-induced oxidative damage. overexpression suppressed apoptotic gene expression, thereby inhibiting apoptosis in response to PEDV stimulation. Taken together, this study demonstrates that AP-2α is involved in PEDV-induced epigenetic modification of to reduce cell apoptosis and oxidative stress and facilitate host resistance to PEDV in the intestinal epithelium.
Topics: Swine; Animals; Porcine epidemic diarrhea virus; Jejunum; Interferon Regulatory Factors; Apoptosis
PubMed: 37593742
DOI: 10.3389/fimmu.2023.1187144 -
Nature Communications Sep 2023Bats, recognized as considerable reservoirs for coronaviruses (CoVs), serve as natural hosts for several highly pathogenic CoVs, including SARS-CoV and SARS-CoV-2....
Bats, recognized as considerable reservoirs for coronaviruses (CoVs), serve as natural hosts for several highly pathogenic CoVs, including SARS-CoV and SARS-CoV-2. Investigating the bat CoV community provides insights into the origin for highly pathogenic CoVs and highlights bat CoVs with potential spillover risks. This study probes the evolution, recombination, host range, geographical distribution, and cross-species transmission characteristics of bat CoVs across China and its associated CoVs in other regions. Through detailed research on 13,064 bat samples from 14 provinces of China, 1141 CoV strains are found across 10 subgenera and one unclassified Alpha-CoV, generating 399 complete genome sequences. Within bat CoVs, 11 new CoV species are identified and 425 recombination events are detected. Bats in southern China, particularly in Yunnan province, exhibit a pronounced diversity of CoVs. Limited sampling and low detection rates exist for CoVs in Myotacovirus, Nyctacovirus, Hibecovirus, Nobecovirus in China. The genus Myotis is highlighted as a potential ancestral host for Alpha-CoV, with the genus Hipposideros suggested as a likely progenitor host for bat-associated Beta-CoV, indicating the complexity of cross-species transmission dynamics. Through the comprehensive analysis, this study enriches the understanding of bat CoVs and offers a valuable resource for future research.
Topics: Animals; Chiroptera; SARS-CoV-2; COVID-19; China; Severe acute respiratory syndrome-related coronavirus; Alphacoronavirus
PubMed: 37684236
DOI: 10.1038/s41467-023-41264-z -
Viruses Sep 2023Although the involvement of the ubiquitin-proteasome system (UPS) in several coronavirus-productive infections has been reported, whether the UPS is required for...
Although the involvement of the ubiquitin-proteasome system (UPS) in several coronavirus-productive infections has been reported, whether the UPS is required for infectious bronchitis virus (IBV) and porcine epidemic diarrhea virus (PEDV) infections is unclear. In this study, the role of UPS in the IBV and PEDV life cycles was investigated. When the UPS was suppressed by pharmacological inhibition at the early infection stage, IBV and PEDV infectivity were severely impaired. Further study showed that inhibition of UPS did not change the internalization of virus particles; however, by using R18 and DiOC-labeled virus particles, we found that inhibition of UPS prevented the IBV and PEDV membrane fusion with late endosomes or lysosomes. In addition, proteasome inhibitors blocked the degradation of the incoming viral protein N, suggesting the uncoating process and genomic RNA release were suppressed. Subsequently, the initial translation of genomic RNA was blocked. Thus, UPS may target the virus-cellular membrane fusion to facilitate the release of incoming viruses from late endosomes or lysosomes, subsequently blocking the following virus uncoating, initial translation, and replication events. Similar to the observation of proteasome inhibitors, ubiquitin-activating enzyme E1 inhibitor PYR-41 also impaired the entry of IBV, enhanced the accumulation of ubiquitinated proteins, and depleted mono-ubiquitin. In all, this study reveals an important role of UPS in coronavirus entry by preventing membrane fusion and identifies UPS as a potential target for developing antiviral therapies for coronavirus.
Topics: Animals; Swine; Proteasome Endopeptidase Complex; Cell Line; Ubiquitin; Coronavirus; Proteasome Inhibitors; Membrane Fusion; Coronavirus Infections; Endosomes; Porcine epidemic diarrhea virus; RNA; Virus Replication
PubMed: 37896778
DOI: 10.3390/v15102001 -
Nature Communications Feb 2024Cepharanthine is a secondary metabolite isolated from Stephania. It has been reported that it has anti-conronaviruses activities including severe acute respiratory...
Cepharanthine is a secondary metabolite isolated from Stephania. It has been reported that it has anti-conronaviruses activities including severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Here, we assemble three Stephania genomes (S. japonica, S. yunnanensis, and S. cepharantha), propose the cepharanthine biosynthetic pathway, and assess the antiviral potential of compounds involved in the pathway. Among the three genomes, S. japonica has a near telomere-to-telomere assembly with one remaining gap, and S. cepharantha and S. yunnanensis have chromosome-level assemblies. Following by biosynthetic gene mining and metabolomics analysis, we identify seven cepharanthine analogs that have broad-spectrum anti-coronavirus activities, including SARS-CoV-2, Guangxi pangolin-CoV (GX_P2V), swine acute diarrhoea syndrome coronavirus (SADS-CoV), and porcine epidemic diarrhea virus (PEDV). We also show that two other genera, Nelumbo and Thalictrum, can produce cepharanthine analogs, and thus have the potential for antiviral compound discovery. Results generated from this study could accelerate broad-spectrum anti-coronavirus drug discovery.
Topics: Animals; Swine; Stephania; China; SARS-CoV-2; Antiviral Agents; Alphacoronavirus; Benzylisoquinolines; Benzodioxoles
PubMed: 38378731
DOI: 10.1038/s41467-024-45690-5 -
Microbiology Spectrum Dec 2023Understanding the role of the endoribonuclease non-structural protein 15 (nsp15) (EndoU) in coronavirus (CoV) infection and pathogenesis is essential for vaccine target...
Understanding the role of the endoribonuclease non-structural protein 15 (nsp15) (EndoU) in coronavirus (CoV) infection and pathogenesis is essential for vaccine target discovery. Whether the EndoU activity of CoV nsp15, as a virulence-related protein, has a diverse effect on viral virulence needs to be further explored. Here, we found that the transmissible gastroenteritis virus (TGEV) and feline infectious peritonitis virus (FIPV) nsp15 proteins antagonize SeV-induced interferon-β (IFN-β) production in human embryonic kidney 293 cells. Interestingly, compared with wild-type infection, infection with EnUmt-TGEV or EnUmt-FIPV did not change the IFN-β response or reduce viral propagation in immunocompetent cells. The results of animal experiments showed that EnUmt viruses did not reduce the clinical presentation and mortality caused by TGEV and FIPV. Our findings enrich the understanding of nsp15-mediated regulation of alpha-CoV propagation and virulence and reveal that the conserved functions of nonstructural proteins have diverse effects on the pathogenicity of CoVs.
Topics: Animals; Humans; Coronavirus; Virulence; Endoribonucleases; Uridylate-Specific Endoribonucleases; Coronavirus Infections
PubMed: 37938022
DOI: 10.1128/spectrum.02209-23 -
Journal of Virology Dec 2023Coronaviruses are important pathogens of humans and animals, and vaccine developments against them are imperative. Due to the ability to induce broad and prolonged...
Coronaviruses are important pathogens of humans and animals, and vaccine developments against them are imperative. Due to the ability to induce broad and prolonged protective immunity and the convenient administration routes, live attenuated vaccines (LAVs) are promising arms for controlling the deadly coronavirus infections. However, potential recombination events between vaccine and field strains raise a safety concern for LAVs. The porcine epidemic diarrhea virus (PEDV) remodeled TRS (RMT) mutant generated in this study replicated efficiently in both cell culture and in pigs and retained protective immunogenicity against PEDV challenge in pigs. Furthermore, the RMT PEDV was resistant to recombination and genetically stable. Therefore, RMT PEDV can be further optimized as a backbone for the development of safe LAVs.
Topics: Animals; Coronavirus Infections; Porcine epidemic diarrhea virus; Recombination, Genetic; Swine; Swine Diseases; Vaccines, Attenuated; Viral Vaccines; Virus Replication; Cells, Cultured; Mutation
PubMed: 37971221
DOI: 10.1128/jvi.01193-23 -
PLoS Pathogens Mar 2024Alphacoronaviruses are the primary coronaviruses responsible for causing severe economic losses in the pig industry with the potential to cause human outbreaks....
Alphacoronaviruses are the primary coronaviruses responsible for causing severe economic losses in the pig industry with the potential to cause human outbreaks. Currently, extensive studies have reported the essential role of endosomal sorting and transport complexes (ESCRT) in the life cycle of enveloped viruses. However, very little information is available about which ESCRT components are crucial for alphacoronaviruses infection. By using RNA interference in combination with Co-immunoprecipitation, as well as fluorescence and electron microscopy approaches, we have dissected the role of ALIX and TSG101 for two porcine alphacoronavirus cellular entry and replication. Results show that infection by two porcine alphacoronaviruses, including porcine epidemic diarrhea virus (PEDV) and porcine enteric alphacoronavirus (PEAV), is dramatically decreased in ALIX- or TSG101-depleted cells. Furthermore, PEDV entry significantly increases the interaction of ALIX with caveolin-1 (CAV1) and RAB7, which are crucial for viral endocytosis and lysosomal transport, however, does not require TSG101. Interestingly, PEAV not only relies on ALIX to regulate viral endocytosis and lysosomal transport, but also requires TSG101 to regulate macropinocytosis. Besides, ALIX and TSG101 are recruited to the replication sites of PEDV and PEAV where they become localized within the endoplasmic reticulum and virus-induced double-membrane vesicles. PEDV and PEAV replication were significantly inhibited by depletion of ALIX and TSG101 in Vero cells or primary jejunal epithelial cells, indicating that ALIX and TSG101 are crucial for PEDV and PEAV replication. Collectively, these data highlight the dual role of ALIX and TSG101 in the entry and replication of two porcine alphacoronaviruses. Thus, ESCRT proteins could serve as therapeutic targets against two porcine alphacoronaviruses infection.
Topics: Animals; Alphacoronavirus; Cell Line; Chlorocebus aethiops; Endosomal Sorting Complexes Required for Transport; Epithelial Cells; Porcine epidemic diarrhea virus; Swine; Vero Cells; Virus Replication; Calcium-Binding Proteins
PubMed: 38489378
DOI: 10.1371/journal.ppat.1012103 -
Veterinary Medicine and Science Nov 2023To investigate intestinal injury, repair and vasculitis biomarkers that may illuminate the progression and/or pathogenesis of feline infectious peritonitis (FIP) or...
OBJECTIVE
To investigate intestinal injury, repair and vasculitis biomarkers that may illuminate the progression and/or pathogenesis of feline infectious peritonitis (FIP) or feline enteric coronavirus (FECV) infection.
MATERIALS AND METHODS
A total of 40 cats with effusive FIP (30 with abdominal effusion, AE group; 10 with thoracic effusion, TE group) and 10 asymptomatic but FECV positive cats (FECV group), all were confirmed by reverse transcription polymerase chain reaction either in faeces or effusion samples. Physical examinations and effusion tests were performed. Trefoil factor-3 (TFF-3), intestinal alkaline phosphatase (IAP), intestinal fatty acid binding protein (I-FABP), myeloperoxidase-anti-neutrophilic cytoplasmic antibody (MPO-ANCA) and proteinase 3-ANCA (PR3-ANCA) concentrations were measured both in serum and effusion samples.
RESULTS
Rectal temperature and respiratory rate were highest in the TE group (p < 0.000). Effusion white blood cell count was higher in the AE group than TE group (p < 0.042). Serum TFF-3, IAP and I-FABP concentrations were higher in cats with effusive FIP than the cats with FECV (p < 0.05). Compared with the AE group, TE group had lower effusion MPO-ANCA (p < 0.036), higher IAP (p < 0.050) and higher TFF-3 (p < 0.016) concentrations.
CLINICAL SIGNIFICANCE
Markers of intestinal and epithelial surface injury were higher in cats with effusive FIP than those with FECV. Compared to cats with abdominal effusions, markers of apoptosis inhibition and immunostimulation to the injured epithelium were more potent in cats with thoracic effusion, suggesting the possibility of a poorer prognosis or more advanced disease in these patients.
Topics: Cats; Animals; Coronavirus, Feline; Feline Infectious Peritonitis; Antibodies, Antineutrophil Cytoplasmic; Coronavirus Infections; Biomarkers; Cat Diseases
PubMed: 37872840
DOI: 10.1002/vms3.1299