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1.
Arch Virol ; 166(8): 2291-2298, 2021 Aug.
Article in English | MEDLINE | ID: covidwho-1258219

ABSTRACT

Infectious bronchitis virus (IBV), an avian coronavirus, is highly contagious. Chickens with IBV infection develop acute pathogenesis in multiple organs, including the respiratory and urogenital tracts. Frequent recombination in the spike (S) glycoprotein gene has made vaccine strategies ineffective. To understand IBV pathogenesis, we analyzed the genetic distance between Korean IBV isolates and other coronaviruses, including SARS-CoV-2. To obtain comprehensive information about early immune responses such as innate cytokine production and associated immune regulation during IBV infection, we infected primary chicken embryonic kidney cells and performed transcriptome analysis. We observed that the functional pathways of innate immunity are regulated and confirmed expression of genes that coordinate early immune responses. Understanding the immune profile of the host cell may assist in vaccine development.


Subject(s)
Infectious bronchitis virus/physiology , Animals , Cells, Cultured , Chickens , Coronavirus Infections/virology , Cytokines/genetics , Gene Expression Profiling , Host-Pathogen Interactions , Immunity, Innate/genetics , Infectious bronchitis virus/classification , Infectious bronchitis virus/genetics , Infectious bronchitis virus/isolation & purification , Kidney/cytology , Phylogeny , Republic of Korea , Spike Glycoprotein, Coronavirus/genetics
2.
Int J Mol Sci ; 22(10)2021 May 20.
Article in English | MEDLINE | ID: covidwho-1244035

ABSTRACT

Previous studies have shown that COVID-19 leads to thrombotic complications, which have been associated with high morbidity and mortality rates. Neutrophils are the largest population of white blood cells and play a pivotal role in innate immunity. During an infection, neutrophils migrate from circulation to the infection site, contributing to killing pathogens. This mechanism is regulated by chemokines such as IL-8. Moreover, it was shown that neutrophils play an important role in thromboinflammation. Through a diverse repertoire of mechanisms, neutrophils, apart from directly killing pathogens, are able to activate the formation of thrombi. In COVID-19 patients, neutrophil activation promotes neutrophil extracellular trap (NET) formation, platelet aggregation, and cell damage. Furthermore, neutrophils participate in the pathogenesis of endothelitis. Overall, this review summarizes recent progress in research on the pathogenesis of COVID-19, highlighting the role of the prothrombotic action of neutrophils in NET formation.


Subject(s)
COVID-19/immunology , Extracellular Traps/immunology , Immunity, Innate , Lung/immunology , Neutrophils/immunology , Thrombosis/immunology , COVID-19/complications , COVID-19/pathology , COVID-19/therapy , Cytokine Release Syndrome/metabolism , Cytokine Release Syndrome/virology , Extracellular Traps/virology , Humans , Inflammation/immunology , Inflammation/pathology , Kidney/cytology , Kidney/immunology , Kidney/pathology , Kidney/virology , Lung/cytology , Lung/pathology , Lung/virology , Mucocutaneous Lymph Node Syndrome/complications , Mucocutaneous Lymph Node Syndrome/immunology , Mucocutaneous Lymph Node Syndrome/virology , SARS-CoV-2 , Thrombosis/complications , Thrombosis/pathology , Thrombosis/virology
3.
Vet Microbiol ; 247: 108785, 2020 Aug.
Article in English | MEDLINE | ID: covidwho-827867

ABSTRACT

Porcine deltacoronavirus (PDCoV) is a novel swine enteropathogenic coronavirus that causes watery diarrhea, vomiting and mortality in nursing piglets. Type III interferons (IFN-λs) are the major antiviral cytokines in intestinal epithelial cells, the target cells in vivo for PDCoV. In this study, we found that PDCoV infection remarkably inhibited Sendai virus-induced IFN-λ1 production by suppressing transcription factors IRF and NF-κB in IPI-2I cells, a line of porcine intestinal mucosal epithelial cells. We also confirmed that PDCoV infection impeded the activation of IFN-λ1 promoter stimulated by RIG-I, MDA5 and MAVS, but not by TBK1 and IRF1. Although the expression levels of IRF1 and MAVS were not changed, PDCoV infection resulted in reduction of the number of peroxisomes, the platform for MAVS to activate IRF1, and subsequent type III IFN production. Taken together, our study demonstrates that PDCoV suppresses type III IFN responses to circumvent the host's antiviral immunity.


Subject(s)
Coronavirus Infections/veterinary , Epithelial Cells/immunology , Epithelial Cells/virology , Host-Pathogen Interactions/immunology , Interferons/antagonists & inhibitors , Animals , Cell Line , Coronavirus , Coronavirus Infections/immunology , Coronavirus Infections/virology , Interferon Regulatory Factor-1/antagonists & inhibitors , Interferon Regulatory Factor-1/immunology , Interferons/immunology , Intestines/cytology , Intestines/virology , Kidney/cytology , Kidney/virology , NF-kappa B/antagonists & inhibitors , NF-kappa B/immunology , Sendai virus/immunology , Signal Transduction/immunology , Swine/virology , Swine Diseases/immunology , Swine Diseases/virology
4.
J Gen Virol ; 101(6): 599-608, 2020 06.
Article in English | MEDLINE | ID: covidwho-662965

ABSTRACT

Infection of chicken coronavirus infectious bronchitis virus (IBV) is initiated by binding of the viral heavily N-glycosylated attachment protein spike to the alpha-2,3-linked sialic acid receptor Neu5Ac. Previously, we have shown that N-glycosylation of recombinantly expressed receptor binding domain (RBD) of the spike of IBV-M41 is of critical importance for binding to chicken trachea tissue. Here we investigated the role of N-glycosylation of the RBD on receptor specificity and virus replication in the context of the virus particle. Using our reverse genetics system we were able to generate recombinant IBVs for nine-out-of-ten individual N-glycosylation mutants. In vitro growth kinetics of these viruses were comparable to the virus containing the wild-type M41-S1. Furthermore, Neu5Ac binding by the recombinant viruses containing single N-glycosylation site knock-out mutations matched the Neu5Ac binding observed with the recombinant RBDs. Five N-glycosylation mutants lost the ability to bind Neu5Ac and gained binding to a different, yet unknown, sialylated glycan receptor on host cells. These results demonstrate that N-glycosylation of IBV is a determinant for receptor specificity.


Subject(s)
Coronavirus Infections/immunology , Host Specificity/immunology , Infectious bronchitis virus/chemistry , Protein Domains , Receptors, Virus/immunology , Spike Glycoprotein, Coronavirus/chemistry , Animals , Cell Line , Chick Embryo , Coronavirus Infections/virology , Glycosylation , Infectious bronchitis virus/immunology , Kidney/cytology , Kidney/embryology , Protein Binding , Receptors, Cell Surface/metabolism , Receptors, Virus/metabolism , Recombinant Proteins , Spike Glycoprotein, Coronavirus/metabolism , Viral Tropism/immunology , Virus Attachment , Virus Replication
5.
Sci Rep ; 10(1): 7257, 2020 04 29.
Article in English | MEDLINE | ID: covidwho-154662

ABSTRACT

Coronaviruses that cause severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) are speculated to have originated in bats. The mechanisms by which these viruses are maintained in individuals or populations of reservoir bats remain an enigma. Mathematical models have predicted long-term persistent infection with low levels of periodic shedding as a likely route for virus maintenance and spillover from bats. In this study, we tested the hypothesis that bat cells and MERS coronavirus (CoV) can co-exist in vitro. To test our hypothesis, we established a long-term coronavirus infection model of bat cells that are persistently infected with MERS-CoV. We infected cells from Eptesicus fuscus with MERS-CoV and maintained them in culture for at least 126 days. We characterized the persistently infected cells by detecting virus particles, protein and transcripts. Basal levels of type I interferon in the long-term infected bat cells were higher, relative to uninfected cells, and disrupting the interferon response in persistently infected bat cells increased virus replication. By sequencing the whole genome of MERS-CoV from persistently infected bat cells, we identified that bat cells repeatedly selected for viral variants that contained mutations in the viral open reading frame 5 (ORF5) protein. Furthermore, bat cells that were persistently infected with ΔORF5 MERS-CoV were resistant to superinfection by wildtype virus, likely due to reduced levels of the virus receptor, dipeptidyl peptidase 4 (DPP4) and higher basal levels of interferon in these cells. In summary, our study provides evidence for a model of coronavirus persistence in bats, along with the establishment of a unique persistently infected cell culture model to study MERS-CoV-bat interactions.


Subject(s)
Chiroptera/virology , Coronavirus Infections/virology , Fibroblasts/virology , Middle East Respiratory Syndrome Coronavirus/genetics , Open Reading Frames/genetics , Point Mutation , Animals , Chiroptera/anatomy & histology , Chlorocebus aethiops , Coronavirus Nucleocapsid Proteins , Dipeptidyl Peptidase 4/metabolism , Fibroblasts/metabolism , Genome, Viral/genetics , Humans , Interferon Regulatory Factor-3/genetics , Interferon Regulatory Factor-3/metabolism , Interferon Type I/metabolism , Kidney/cytology , Mitogen-Activated Protein Kinases/genetics , Mitogen-Activated Protein Kinases/metabolism , Nucleocapsid Proteins/genetics , Receptors, Virus/metabolism , Transfection , Vero Cells , Virus Replication/genetics , Whole Genome Sequencing
6.
Viral Immunol ; 33(6): 468-476, 2020.
Article in English | MEDLINE | ID: covidwho-94792

ABSTRACT

As a zoonotic disease, ovine contagious pustular dermatitis (Orf) is a serious threat to sheep as well as humans. Orf virus (ORFV) interferon resistance protein (VIR) is the principal virulence protein that encodes a dsRNA-binding protein to inhibit host antiviral response. p53 is one of the key proteins of the host antiviral innate immunity. It not only enhances type I interferon secretion but also induces apoptosis in infected cells, and plays a crucial role in the immune response against various viral infections. However, it remains to be elucidated what role p53 plays in ORFV replication and whether ORFV's own protein VIR regulates p53 expression to promote self-replication. In this study, we showed that p53 has an antiviral effect on ORFV and can inhibit ORFV replication. In addition, ORFV nonstructural protein VIR interacts with p53 and degrades p53, which inhibits p53-mediated positive regulation of downstream antiviral genes. This study provides new insight into the immune evasion mediated by ORFV and identifies VIR as an antagonistic factor for ORFV to evade the antiviral response.


Subject(s)
Host Microbial Interactions/genetics , Orf virus/genetics , Tumor Suppressor Protein p53/genetics , Viral Proteins/genetics , Virus Replication/genetics , Animals , Cell Line , Cricetinae , Ecthyma, Contagious/virology , Fibroblasts/immunology , Fibroblasts/virology , Gene Expression Regulation, Viral , Goats , Immune Evasion/genetics , Immunity, Innate , Kidney/cytology , Orf virus/physiology , Sheep , Skin/cytology , Viral Proteins/metabolism
7.
Cell ; 181(4): 905-913.e7, 2020 05 14.
Article in English | MEDLINE | ID: covidwho-30638

ABSTRACT

We have previously provided the first genetic evidence that angiotensin converting enzyme 2 (ACE2) is the critical receptor for severe acute respiratory syndrome coronavirus (SARS-CoV), and ACE2 protects the lung from injury, providing a molecular explanation for the severe lung failure and death due to SARS-CoV infections. ACE2 has now also been identified as a key receptor for SARS-CoV-2 infections, and it has been proposed that inhibiting this interaction might be used in treating patients with COVID-19. However, it is not known whether human recombinant soluble ACE2 (hrsACE2) blocks growth of SARS-CoV-2. Here, we show that clinical grade hrsACE2 reduced SARS-CoV-2 recovery from Vero cells by a factor of 1,000-5,000. An equivalent mouse rsACE2 had no effect. We also show that SARS-CoV-2 can directly infect engineered human blood vessel organoids and human kidney organoids, which can be inhibited by hrsACE2. These data demonstrate that hrsACE2 can significantly block early stages of SARS-CoV-2 infections.


Subject(s)
Betacoronavirus/drug effects , Coronavirus Infections/drug therapy , Peptidyl-Dipeptidase A/pharmacology , Pneumonia, Viral/drug therapy , Recombinant Proteins/pharmacology , Angiotensin-Converting Enzyme 2 , Animals , Betacoronavirus/genetics , Betacoronavirus/isolation & purification , Betacoronavirus/ultrastructure , Blood Vessels/virology , COVID-19 , Chlorocebus aethiops , Humans , Kidney/cytology , Kidney/virology , Mice , Organoids/virology , Pandemics , Peptidyl-Dipeptidase A/genetics , Peptidyl-Dipeptidase A/metabolism , Receptors, Virus/metabolism , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/metabolism , Vero Cells
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