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1.
Cell Rep ; 38(10): 110502, 2022 03 08.
Article in English | MEDLINE | ID: covidwho-1757194

ABSTRACT

Since the vast majority of species solely rely on innate immunity for host defense, it stands to reason that a critical evolutionary trait like immunological memory evolved in this primitive branch of our immune system. There is ample evidence that vaccines such as bacillus Calmette-Guérin (BCG) induce protective innate immune memory responses (trained immunity) against heterologous pathogens. Here we show that while BCG vaccination significantly reduces morbidity and mortality against influenza A virus (IAV), it fails to provide protection against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). In contrast to IAV, SARS-CoV-2 infection leads to unique pulmonary vasculature damage facilitating viral dissemination to other organs, including the bone marrow (BM), a central site for BCG-mediated trained immunity. Finally, monocytes from BCG-vaccinated individuals mount an efficient cytokine response to IAV infection, while this response is minimal following SARS-CoV-2. Collectively, our data suggest that the protective capacity of BCG vaccination is contingent on viral pathogenesis and tissue tropism.


Subject(s)
COVID-19 , Influenza A virus , BCG Vaccine , COVID-19/prevention & control , Humans , Immunity, Innate , SARS-CoV-2 , Vaccination
2.
Chemistry ; 28(15): e202200524, 2022 Mar 10.
Article in English | MEDLINE | ID: covidwho-1750335

ABSTRACT

Invited for the cover of this issue are John Brennan, Yingfu Li, and co-workers at McMaster University. The image depicts MSA52 as a universal DNA aptamer that recognizes spike proteins of diverse SARS-CoV-2 variants of concern. Read the full text of the article at 10.1002/chem.202200078.

4.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-309487

ABSTRACT

The compounding challenges of low signal, high background, and uncertain targets plague many sequencing efforts, including monitoring potential zoonotic resevoirs. One solution has been targeted DNA capture, where probes are designed to hybridize with target sequences, enriching them relative to the background. We have developed the HUBDesign pipeline which makes use of sequence homology to design probes at multiple taxonomic levels. This creates an efficient probe set capable of simultaneously and specifically capturing known and potentially novel sequences. We validated HUBDesign by generating a probe set targeting the breadth of coronavirus diversity. We demonstrated significant enrichment of SARS-CoV-2 and HCoV-NL63 from a human background, without interference between the two viruses, nor background enrichment. This probe set will be of use in identifying coronavirus co-infections and surveillance of coronaviruses resevoirs. HUBDesign has broad applicability wherever there are multiple organisms of interest, such as ancient DNA, and host specific microbiomes.Funding Statement: This work was partially supported by CIHR COVID-19 Rapid Response funding to MSM. MSM was supported in part by a CIHR New Investigator Award and an Early Career Researcher Award from the Government of Ontario. This work was partially funded by a CIHR COVID grant to Principal applicant KM and co-applicant AB. AB, HP, GBG, and ZWD were funded through Natural Sciences and Engineering Research Council of Canada.HP was generously funded by the Boris Family Fund, the Micheal G. DeGroote Institute for Infectious Disease Research.Declaration of Interests: None to declareEthics Approval Statement: Work with SARS-CoV-2 was performed in a containment level 3 laboratory and all protocols were approved by the McMaster Presidential Biosafety Advisory Committee.

5.
Lab Chip ; 22(6): 1171-1186, 2022 03 15.
Article in English | MEDLINE | ID: covidwho-1684131

ABSTRACT

Coronavirus disease 2019 (COVID-19) was primarily identified as a novel disease causing acute respiratory syndrome. However, as the pandemic progressed various cases of secondary organ infection and damage by severe respiratory syndrome coronavirus 2 (SARS-CoV-2) have been reported, including a breakdown of the vascular barrier. As SARS-CoV-2 gains access to blood circulation through the lungs, the virus is first encountered by the layer of endothelial cells and immune cells that participate in host defense. Here, we developed an approach to study SARS-CoV-2 infection using vasculature-on-a-chip. We first modeled the interaction of virus alone with the endothelialized vasculature-on-a-chip, followed by the studies of the interaction of the virus exposed-endothelial cells with peripheral blood mononuclear cells (PBMCs). In an endothelial model grown on a permeable microfluidic bioscaffold under flow conditions, both human coronavirus (HCoV)-NL63 and SARS-CoV-2 presence diminished endothelial barrier function by disrupting VE-cadherin junctions and elevating the level of pro-inflammatory cytokines such as interleukin (IL)-6, IL-8, and angiopoietin-2. Inflammatory cytokine markers were markedly more elevated upon SARS-CoV-2 infection compared to HCoV-NL63 infection. Introduction of PBMCs with monocytes into the vasculature-on-a-chip upon SARS-CoV-2 infection further exacerbated cytokine-induced endothelial dysfunction, demonstrating the compounding effects of inter-cellular crosstalk between endothelial cells and monocytes in facilitating the hyperinflammatory state. Considering the harmful effects of SARS-CoV-2 on endothelial cells, even without active virus proliferation inside the cells, a potential therapeutic approach is critical. We identified angiopoietin-1 derived peptide, QHREDGS, as a potential therapeutic capable of profoundly attenuating the inflammatory state of the cells consistent with the levels in non-infected controls, thereby improving the barrier function and endothelial cell survival against SARS-CoV-2 infection in the presence of PBMC.


Subject(s)
Angiopoietin-1 , COVID-19 , Endothelium, Vascular , Inflammation , SARS-CoV-2 , COVID-19/drug therapy , COVID-19/virology , Endothelial Cells/immunology , Endothelial Cells/virology , Endothelium, Vascular/immunology , Endothelium, Vascular/virology , Humans , Immunity, Innate , Inflammation/drug therapy , Inflammation/virology , Lab-On-A-Chip Devices , Leukocytes, Mononuclear
6.
Cell ; 185(5): 896-915.e19, 2022 03 03.
Article in English | MEDLINE | ID: covidwho-1670278

ABSTRACT

The emerging SARS-CoV-2 variants of concern (VOCs) threaten the effectiveness of current COVID-19 vaccines administered intramuscularly and designed to only target the spike protein. There is a pressing need to develop next-generation vaccine strategies for broader and long-lasting protection. Using adenoviral vectors (Ad) of human and chimpanzee origin, we evaluated Ad-vectored trivalent COVID-19 vaccines expressing spike-1, nucleocapsid, and RdRp antigens in murine models. We show that single-dose intranasal immunization, particularly with chimpanzee Ad-vectored vaccine, is superior to intramuscular immunization in induction of the tripartite protective immunity consisting of local and systemic antibody responses, mucosal tissue-resident memory T cells and mucosal trained innate immunity. We further show that intranasal immunization provides protection against both the ancestral SARS-CoV-2 and two VOC, B.1.1.7 and B.1.351. Our findings indicate that respiratory mucosal delivery of Ad-vectored multivalent vaccine represents an effective next-generation COVID-19 vaccine strategy to induce all-around mucosal immunity against current and future VOC.


Subject(s)
COVID-19 Vaccines/administration & dosage , COVID-19/prevention & control , Immunity, Mucosal , Administration, Intranasal , Animals , Antibodies, Viral/blood , Antibodies, Viral/immunology , B-Lymphocytes/immunology , B-Lymphocytes/metabolism , COVID-19/virology , COVID-19 Vaccines/immunology , Cytokines/blood , Genetic Vectors/genetics , Genetic Vectors/immunology , Genetic Vectors/metabolism , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Neutralization Tests , Nucleocapsid/genetics , Nucleocapsid/immunology , Nucleocapsid/metabolism , Pan troglodytes , SARS-CoV-2/genetics , SARS-CoV-2/immunology , SARS-CoV-2/isolation & purification , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/metabolism , T-Lymphocytes/immunology , T-Lymphocytes/metabolism
7.
Chemistry ; 28(15): e202200078, 2022 Mar 10.
Article in English | MEDLINE | ID: covidwho-1653193

ABSTRACT

We report on a unique DNA aptamer, denoted MSA52, that displays universally high affinity for the spike proteins of wildtype SARS-CoV-2 as well as the Alpha, Beta, Gamma, Epsilon, Kappa, Delta and Omicron variants. Using an aptamer pool produced from round 13 of selection against the S1 domain of the wildtype spike protein, we carried out one-round SELEX experiments using five different trimeric spike proteins from variants, followed by high-throughput sequencing and sequence alignment analysis of aptamers that formed complexes with all proteins. A previously unidentified aptamer, MSA52, showed Kd values ranging from 2 to 10 nM for all variant spike proteins, and also bound similarly to variants not present in the reselection experiments. This aptamer also recognized pseudotyped lentiviruses (PL) expressing eight different spike proteins of SARS-CoV-2 with Kd values between 20 and 50 pM, and was integrated into a simple colorimetric assay for detection of multiple PL variants. This discovery provides evidence that aptamers can be generated with high affinity to multiple variants of a single protein, including emerging variants, making it well-suited for molecular recognition of rapidly evolving targets such as those found in SARS-CoV-2.


Subject(s)
Aptamers, Nucleotide , COVID-19 , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Aptamers, Nucleotide/genetics , Aptamers, Nucleotide/metabolism , COVID-19/virology , Humans , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism
8.
Sci Adv ; 8(3): eabj9815, 2022 Jan 21.
Article in English | MEDLINE | ID: covidwho-1634773

ABSTRACT

Safe and effective vaccines are needed to end the COVID-19 pandemic. Here, we report the preclinical development of a lipid nanoparticle­formulated SARS-CoV-2 mRNA vaccine, PTX-COVID19-B. PTX-COVID19-B was chosen among three candidates after the initial mouse vaccination results showed that it elicited the strongest neutralizing antibody response against SARS-CoV-2. Further tests in mice and hamsters indicated that PTX-COVID19-B induced robust humoral and cellular immune responses and completely protected the vaccinated animals from SARS-CoV-2 infection in the lung. Studies in hamsters also showed that PTX-COVID19-B protected the upper respiratory tract from SARS-CoV-2 infection. Mouse immune sera elicited by PTX-COVID19-B vaccination were able to neutralize SARS-CoV-2 variants of concern, including the Alpha, Beta, Gamma, and Delta lineages. No adverse effects were induced by PTX-COVID19-B in either mice or hamsters. Based on these results, PTX-COVID19-B was authorized by Health Canada to enter clinical trials in December 2020 with a phase 2 clinical trial ongoing.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19/prevention & control , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Vaccines, Synthetic/immunology , /immunology , Animals , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , CD4 Lymphocyte Count , CD8-Positive T-Lymphocytes/immunology , COVID-19/immunology , COVID-19 Vaccines/adverse effects , Canada , Cell Line , Cricetinae , Drug Evaluation, Preclinical , Female , HEK293 Cells , Humans , Immunity, Cellular/immunology , Immunity, Humoral/immunology , Liposomes/pharmacology , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Nanoparticles , Spike Glycoprotein, Coronavirus/genetics , Th1 Cells/immunology
9.
Viruses ; 14(1)2021 12 30.
Article in English | MEDLINE | ID: covidwho-1580401

ABSTRACT

Medicinal chemistry optimization of a previously described stilbene inhibitor of HIV-1, 5350150 (2-(2-(5-nitro-2-thienyl)vinyl)quinoline), led to the identification of the thiazole-5-carboxamide derivative (GPS491), which retained potent anti-HIV-1 activity with reduced toxicity. In this report, we demonstrate that the block of HIV-1 replication by GPS491 is accompanied by a drastic inhibition of viral gene expression (IC50 ~ 0.25 µM), and alterations in the production of unspliced, singly spliced, and multiply spliced HIV-1 RNAs. GPS491 also inhibited the replication of adenovirus and multiple coronaviruses. Low µM doses of GPS491 reduced adenovirus infectious yield ~1000 fold, altered virus early gene expression/viral E1A RNA processing, blocked viral DNA amplification, and inhibited late (hexon) gene expression. Loss of replication of multiple coronaviruses (229E, OC43, SARS-CoV2) upon GPS491 addition was associated with the inhibition of viral structural protein expression and the formation of virus particles. Consistent with the observed changes in viral RNA processing, GPS491 treatment induced selective alterations in the accumulation/phosphorylation/function of splicing regulatory SR proteins. Our study establishes that a compound that impacts the activity of cellular factors involved in RNA processing can prevent the replication of several viruses with minimal effect on cell viability.


Subject(s)
Adenoviridae/drug effects , Antiviral Agents/pharmacology , Coronavirus/drug effects , HIV-1/drug effects , RNA Processing, Post-Transcriptional/drug effects , Thiazoles/pharmacology , Virus Replication/drug effects , Adenoviridae/physiology , Antiviral Agents/chemistry , Cell Line , Coronavirus/classification , Coronavirus/physiology , Gene Expression/drug effects , HIV-1/physiology , Humans , RNA Splicing Factors/metabolism , RNA, Viral/metabolism , Thiazoles/chemistry
10.
Cell Biosci ; 11(1): 202, 2021 Dec 08.
Article in English | MEDLINE | ID: covidwho-1562007

ABSTRACT

BACKGROUND: The ongoing COVID-19 pandemic has resulted in 185 million recorded cases and over 4 million deaths worldwide. Several COVID-19 vaccines have been approved for emergency use in humans and are being used in many countries. However, all the approved vaccines are administered by intramuscular injection and this may not prevent upper airway infection or viral transmission. RESULTS: Here, we describe a novel, intranasally delivered COVID-19 vaccine based on a helper-dependent adenoviral (HD-Ad) vector. The vaccine (HD-Ad_RBD) produces a soluble secreted form of the receptor binding domain (RBD) of the SARS-CoV-2 spike protein and we show it induced robust mucosal and systemic immunity. Moreover, intranasal immunization of K18-hACE2 mice with HD-Ad_RBD using a prime-boost regimen, resulted in complete protection of the upper respiratory tract against SARS-CoV-2 infection. CONCLUSION: Our approaches provide a powerful platform for constructing highly effective vaccines targeting SARS-CoV-2 and its emerging variants.

11.
Virol J ; 18(1): 166, 2021 08 13.
Article in English | MEDLINE | ID: covidwho-1533268

ABSTRACT

The emergence of a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and more recently, the independent evolution of multiple SARS-CoV-2 variants has generated renewed interest in virus evolution and cross-species transmission. While all known human coronaviruses (HCoVs) are speculated to have originated in animals, very little is known about their evolutionary history and factors that enable some CoVs to co-exist with humans as low pathogenic and endemic infections (HCoV-229E, HCoV-NL63, HCoV-OC43, HCoV-HKU1), while others, such as SARS-CoV, MERS-CoV and SARS-CoV-2 have evolved to cause severe disease. In this review, we highlight the origins of all known HCoVs and map positively selected for mutations within HCoV proteins to discuss the evolutionary trajectory of SARS-CoV-2. Furthermore, we discuss emerging mutations within SARS-CoV-2 and variants of concern (VOC), along with highlighting the demonstrated or speculated impact of these mutations on virus transmission, pathogenicity, and neutralization by natural or vaccine-mediated immunity.


Subject(s)
COVID-19 Vaccines , COVID-19/virology , SARS-CoV-2/genetics , Animals , COVID-19/transmission , Coronavirus 229E, Human/genetics , Coronavirus 229E, Human/immunology , Coronavirus 229E, Human/pathogenicity , Coronavirus NL63, Human/genetics , Coronavirus NL63, Human/immunology , Coronavirus NL63, Human/pathogenicity , Coronavirus OC43, Human/genetics , Coronavirus OC43, Human/immunology , Coronavirus OC43, Human/pathogenicity , Humans , Immunity , Mutation , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity
12.
Angewandte Chemie ; 133(45):24468-24476, 2021.
Article in English | ProQuest Central | ID: covidwho-1482111

ABSTRACT

We report a simple and rapid saliva‐based SARS‐CoV‐2 antigen test that utilizes a newly developed dimeric DNA aptamer, denoted as DSA1N5, that specifically recognizes the spike proteins of the wildtype virus and its Alpha and Delta variants with dissociation constants of 120, 290 and 480 pM, respectively, and binds pseudotyped lentiviruses expressing the wildtype and alpha trimeric spike proteins with affinity constants of 2.1 pM and 2.3 pM, respectively. To develop a highly sensitive test, DSA1N5 was immobilized onto gold electrodes to produce an electrochemical impedance sensor, which was capable of detecting 1000 viral particles per mL in 1:1 diluted saliva in under 10 min without any further sample processing. Evaluation of 36 positive and 37 negative patient saliva samples produced a clinical sensitivity of 80.5 % and specificity of 100 % and the sensor could detect the wildtype virus as well as the Alpha and Delta variants in the patient samples, which is the first reported rapid test that can detect any emerging variant of SARS‐CoV‐2.

13.
Cell Rep ; 37(4): 109892, 2021 10 26.
Article in English | MEDLINE | ID: covidwho-1458753

ABSTRACT

The main viral protease (3CLpro) is indispensable for SARS-CoV-2 replication. We delineate the human protein substrate landscape of 3CLpro by TAILS substrate-targeted N-terminomics. We identify more than 100 substrates in human lung and kidney cells supported by analyses of SARS-CoV-2-infected cells. Enzyme kinetics and molecular docking simulations of 3CLpro engaging substrates reveal how noncanonical cleavage sites, which diverge from SARS-CoV, guide substrate specificity. Cleaving the interactors of essential effector proteins, effectively stranding them from their binding partners, amplifies the consequences of proteolysis. We show that 3CLpro targets the Hippo pathway, including inactivation of MAP4K5, and key effectors of transcription, mRNA processing, and translation. We demonstrate that Spike glycoprotein directly binds galectin-8, with galectin-8 cleavage disengaging CALCOCO2/NDP52 to decouple antiviral-autophagy. Indeed, in post-mortem COVID-19 lung samples, NDP52 rarely colocalizes with galectin-8, unlike in healthy lungs. The 3CLpro substrate degradome establishes a foundational substrate atlas to accelerate exploration of SARS-CoV-2 pathology and drug design.


Subject(s)
COVID-19 , Coronavirus 3C Proteases/metabolism , SARS-CoV-2/metabolism , Humans , Substrate Specificity
14.
Cell Host Microbe ; 29(2): 160-164, 2021 02 10.
Article in English | MEDLINE | ID: covidwho-1385266

ABSTRACT

The emergence of alternate variants of SARS-CoV-2 due to ongoing adaptations in humans and following human-to-animal transmission has raised concern over the efficacy of vaccines against new variants. We describe human-to-animal transmission (zooanthroponosis) of SARS-CoV-2 and its implications for faunal virus persistence and vaccine-mediated immunity.


Subject(s)
COVID-19/veterinary , Communicable Diseases, Emerging/veterinary , SARS-CoV-2/pathogenicity , Zoonoses/transmission , Zoonoses/virology , Animals , COVID-19/immunology , COVID-19/transmission , COVID-19/virology , Communicable Diseases, Emerging/transmission , Communicable Diseases, Emerging/virology , Disease Reservoirs/veterinary , Disease Reservoirs/virology , Humans , Immunity , Viral Vaccines/immunology
15.
Nat Commun ; 12(1): 5148, 2021 08 26.
Article in English | MEDLINE | ID: covidwho-1376197

ABSTRACT

Coronavirus infection in humans is usually associated to respiratory tract illnesses, ranging in severity from mild to life-threatening respiratory failure. The aryl hydrocarbon receptor (AHR) was recently identified as a host factor for Zika and dengue viruses; AHR antagonists boost antiviral immunity, decrease viral titers and ameliorate Zika-induced pathology in vivo. Here we report that AHR is activated by infection with different coronaviruses, potentially impacting antiviral immunity and lung epithelial cells. Indeed, the analysis of single-cell RNA-seq from lung tissue detected increased expression of AHR and AHR transcriptional targets, suggesting AHR signaling activation in SARS-CoV-2-infected epithelial cells from COVID-19 patients. Moreover, we detected an association between AHR expression and viral load in SARS-CoV-2 infected patients. Finally, we found that the pharmacological inhibition of AHR suppressed the replication in vitro of one of the causative agents of the common cold, HCoV-229E, and the causative agent of the COVID-19 pandemic, SARS-CoV-2. Taken together, these findings suggest that AHR activation is a common strategy used by coronaviruses to evade antiviral immunity and promote viral replication, which may also contribute to lung pathology. Future studies should further evaluate the potential of AHR as a target for host-directed antiviral therapy.


Subject(s)
Coronavirus Infections/metabolism , Coronavirus/physiology , Receptors, Aryl Hydrocarbon/metabolism , Signal Transduction , COVID-19/genetics , COVID-19/metabolism , COVID-19/virology , Coronavirus Infections/genetics , Coronavirus Infections/virology , Epithelial Cells/metabolism , Epithelial Cells/virology , Female , Humans , Male , Receptors, Aryl Hydrocarbon/genetics , SARS-CoV-2/physiology
16.
Trends Microbiol ; 29(10): 871-873, 2021 10.
Article in English | MEDLINE | ID: covidwho-1331264

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) evolution is expected, given the nature of virus replication. Selection and establishment of variants in the human population depend on viral fitness and on molecular and immunological selection pressures. Here we discuss how mechanisms of replication and recombination may contribute to the emergence of current and future variants of SARS-CoV-2.


Subject(s)
COVID-19/virology , SARS-CoV-2/genetics , Genome, Viral , Humans , Recombination, Genetic , SARS-CoV-2/physiology , Virus Replication
17.
Nucleic Acids Res ; 49(13): 7267-7279, 2021 07 21.
Article in English | MEDLINE | ID: covidwho-1298981

ABSTRACT

We performed in vitro selection experiments to identify DNA aptamers for the S1 subunit of the SARS-CoV-2 spike protein (S1 protein). Using a pool of pre-structured random DNA sequences, we obtained over 100 candidate aptamers after 13 cycles of enrichment under progressively more stringent selection pressure. The top 10 sequences all exhibited strong binding to the S1 protein. Two aptamers, named MSA1 (Kd = 1.8 nM) and MSA5 (Kd = 2.7 nM), were assessed for binding to the heat-treated S1 protein, untreated S1 protein spiked into 50% human saliva and the trimeric spike protein of both the wildtype and the B.1.1.7 variant, demonstrating comparable affinities in all cases. MSA1 and MSA5 also recognized the pseudotyped lentivirus of SARS-CoV-2 with respective Kd values of 22.7 pM and 11.8 pM. Secondary structure prediction and sequence truncation experiments revealed that both MSA1 and MSA5 adopted a hairpin structure, which was the motif pre-designed into the original library. A colorimetric sandwich assay was developed using MSA1 as both the recognition element and detection element, which was capable of detecting the pseudotyped lentivirus in 50% saliva with a limit of detection of 400 fM, confirming the potential of these aptamers as diagnostic tools for COVID-19 detection.


Subject(s)
Aptamers, Nucleotide , COVID-19/virology , Gene Library , Mutation , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Aptamers, Nucleotide/chemistry , Aptamers, Nucleotide/genetics , Base Pairing , Base Sequence , COVID-19/diagnosis , Colorimetry/methods , Humans , Nucleic Acid Conformation , SELEX Aptamer Technique
18.
iScience ; 24(5): 102477, 2021 May 21.
Article in English | MEDLINE | ID: covidwho-1201540

ABSTRACT

Type I interferons (IFNs) are our first line of defense against virus infection. Recent studies have suggested the ability of SARS-CoV-2 proteins to inhibit IFN responses. Emerging data also suggest that timing and extent of IFN production is associated with manifestation of COVID-19 severity. In spite of progress in understanding how SARS-CoV-2 activates antiviral responses, mechanistic studies into wild-type SARS-CoV-2-mediated induction and inhibition of human type I IFN responses are scarce. Here we demonstrate that SARS-CoV-2 infection induces a type I IFN response in vitro and in moderate cases of COVID-19. In vitro stimulation of type I IFN expression and signaling in human airway epithelial cells is associated with activation of canonical transcriptions factors, and SARS-CoV-2 is unable to inhibit exogenous induction of these responses. Furthermore, we show that physiological levels of IFNα detected in patients with moderate COVID-19 is sufficient to suppress SARS-CoV-2 replication in human airway cells.

19.
Cell Host Microbe ; 29(2): 160-164, 2021 02 10.
Article in English | MEDLINE | ID: covidwho-1064929

ABSTRACT

The emergence of alternate variants of SARS-CoV-2 due to ongoing adaptations in humans and following human-to-animal transmission has raised concern over the efficacy of vaccines against new variants. We describe human-to-animal transmission (zooanthroponosis) of SARS-CoV-2 and its implications for faunal virus persistence and vaccine-mediated immunity.


Subject(s)
COVID-19/veterinary , Communicable Diseases, Emerging/veterinary , SARS-CoV-2/pathogenicity , Zoonoses/transmission , Zoonoses/virology , Animals , COVID-19/immunology , COVID-19/transmission , COVID-19/virology , Communicable Diseases, Emerging/transmission , Communicable Diseases, Emerging/virology , Disease Reservoirs/veterinary , Disease Reservoirs/virology , Humans , Immunity , Viral Vaccines/immunology
20.
J Gen Virol ; 101(12): 1251-1260, 2020 12.
Article in English | MEDLINE | ID: covidwho-1066517

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) recently emerged to cause widespread infections in humans. SARS-CoV-2 infections have been reported in the Kingdom of Saudi Arabia, where Middle East respiratory syndrome coronavirus (MERS-CoV) causes seasonal outbreaks with a case fatality rate of ~37 %. Here we show that there exists a theoretical possibility of future recombination events between SARS-CoV-2 and MERS-CoV RNA. Through computational analyses, we have identified homologous genomic regions within the ORF1ab and S genes that could facilitate recombination, and have analysed co-expression patterns of the cellular receptors for SARS-CoV-2 and MERS-CoV, ACE2 and DPP4, respectively, to identify human anatomical sites that could facilitate co-infection. Furthermore, we have investigated the likely susceptibility of various animal species to MERS-CoV and SARS-CoV-2 infection by comparing known virus spike protein-receptor interacting residues. In conclusion, we suggest that a recombination between SARS-CoV-2 and MERS-CoV RNA is possible and urge public health laboratories in high-risk areas to develop diagnostic capability for the detection of recombined coronaviruses in patient samples.


Subject(s)
Middle East Respiratory Syndrome Coronavirus/genetics , Reassortant Viruses , SARS-CoV-2/genetics , Animals , Base Sequence , Coinfection , Gene Expression Regulation, Viral , Genome, Viral , Host Specificity , Humans , Models, Molecular , Phylogeny , Protein Conformation , Receptors, Cell Surface , Recombination, Genetic , Viral Proteins/chemistry , Viral Proteins/genetics , Viral Proteins/metabolism
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