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1.
Microbes Infect ; 22(4-5): 226-229, 2020.
Article in English | MEDLINE | ID: covidwho-1386324

ABSTRACT

During virus infection, host toll-like receptors (TLRs) can recognize different pathogen-associated molecular patterns and trigger the innate immune response. TLR7/8 can identify the single-stranded RNA (ssRNA) of the virus. This study aimed to search ssRNA sequences recognized by TLR7/8 from the SARS-CoV-2, SARS-CoV, and MERS-CoV whole genomes by a bioinformatic technique. The immunoinformatic approach showed that the SARS-CoV-2 genome has more ssRNA fragments that could be recognized by TLR7/8 than the SARS-CoV genome. These findings suggest innate immune hyperactivation by SARS-CoV-2. This activity is possibly able to provoke a robust proinflammatory response via TLR7/8 recognition and cause acute lung injury.


Subject(s)
Betacoronavirus/physiology , Coronavirus Infections/virology , Middle East Respiratory Syndrome Coronavirus/physiology , Pneumonia, Viral/virology , SARS Virus/physiology , Toll-Like Receptor 7/physiology , Toll-Like Receptor 8/physiology , COVID-19 , Computational Biology , Genome, Viral , Humans , Immunity, Innate , Pandemics , SARS-CoV-2 , Virus Attachment
2.
Curr Diabetes Rev ; 2021 06 01.
Article in English | MEDLINE | ID: covidwho-1367728

ABSTRACT

The article has been withdrawn at the request of the authors and editor of the journal Current Diabetes Reviews, due to incoherent content.Bentham Science apologizes to the readers of the journal for any inconvenience this may have caused.The Bentham Editorial Policy on Article Withdrawal can be found at https://benthamscience.com/editorial-policies-main.php. BENTHAM SCIENCE DISCLAIMER: It is a condition of publication that manuscripts submitted to this journal have not been published and will not be simultaneously submitted or published elsewhere. Furthermore, any data, illustration, structure or table that has been published elsewhere must be reported, and copyright permission for reproduction must be obtained. Plagiarism is strictly forbidden, and by submit-ting the article for publication the authors agree that the publishers have the legal right to take appropriate action against the authors, if plagiarism or fabricated information is discovered. By submitting a manuscript, the authors agree that the copyright of their article is transferred to the publishers if and when the article is accepted for publication.

3.
Methods Mol Biol ; 2099: 89-97, 2020.
Article in English | MEDLINE | ID: covidwho-1292547

ABSTRACT

The Middle East respiratory syndrome (MERS) is the second novel zoonotic disease infecting humans caused by coronavirus (CoV) in this century. To date, more than 2200 laboratory-confirmed human cases have been identified in 27 countries, and more than 800 MERS-CoV associated deaths have been reported since its outbreak in 2012. Rapid laboratory diagnosis of MERS-CoV is the key to successful containment and prevention of the spread of infection. Though the gold standard for diagnosing MERS-CoV infection in humans is still nucleic acid amplification test (NAAT) of the up-E region, an antigen capture enzyme-linked immunosorbent assay (ELISA) could also be of use for early diagnosis in less developed locations. In the present method, a step-by-step guide to perform a MERS-CoV nucleocapsid protein (NP) capture ELISA using two NP-specific monoclonal antibodies is provided for readers to develop their in-house workflow or diagnostic kit for clinical use and for mass-screening project of animals (e.g., dromedaries and bats) to better understand the spread and evolution of the virus.


Subject(s)
Antigens, Viral/immunology , Coronavirus Infections/diagnosis , Enzyme-Linked Immunosorbent Assay/methods , Middle East Respiratory Syndrome Coronavirus/immunology , Nucleocapsid Proteins/immunology , Animals , Camelus/virology , Chiroptera/virology , Coronavirus Infections/virology , Coronavirus Nucleocapsid Proteins , Humans , Middle East Respiratory Syndrome Coronavirus/isolation & purification , Zoonoses
4.
Methods Mol Biol ; 2099: 137-159, 2020.
Article in English | MEDLINE | ID: covidwho-1292550

ABSTRACT

Since 2012, monthly cases of Middle East respiratory syndrome coronavirus (MERS-CoV) continue to cause severe respiratory disease that is fatal in ~35% of diagnosed individuals. The ongoing threat to global public health and the need for novel therapeutic countermeasures have driven the development of animal models that can reproducibly replicate the pathology associated with MERS-CoV in human infections. The inability of MERS-CoV to replicate in the respiratory tracts of mice, hamsters, and ferrets stymied initial attempts to generate small animal models. Identification of human dipeptidyl peptidase IV (hDPP4) as the receptor for MERS-CoV infection opened the door for genetic engineering of mice. Precise molecular engineering of mouse DPP4 (mDPP4) with clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 technology maintained inherent expression profiles, and limited MERS-CoV susceptibility to tissues that naturally express mDPP4, notably the lower respiratory tract wherein MERS-CoV elicits severe pulmonary pathology. Here, we describe the generation of the 288-330+/+ MERS-CoV mouse model in which mice were made susceptible to MERS-CoV by modifying two amino acids on mDPP4 (A288 and T330), and the use of adaptive evolution to generate novel MERS-CoV isolates that cause fatal respiratory disease. The 288-330+/+ mice are currently being used to evaluate novel drug, antibody, and vaccine therapeutic countermeasures for MERS-CoV. The chapter starts with a historical perspective on the emergence of MERS-CoV and animal models evaluated for MERS-CoV pathogenesis, and then outlines the development of the 288-330+/+ mouse model, assays for assessing a MERS-CoV pulmonary infection in a mouse model, and describes some of the challenges associated with using genetically engineered mice.


Subject(s)
Coronavirus Infections/virology , Dipeptidyl Peptidase 4/genetics , Disease Models, Animal , Mice/genetics , Middle East Respiratory Syndrome Coronavirus/physiology , Respiratory Distress Syndrome/virology , Animals , CRISPR-Cas Systems , Coronavirus Infections/pathology , Dipeptidyl Peptidase 4/metabolism , Disease Susceptibility , Female , Genetic Engineering , Humans , Lung/virology , Male , Mice, Inbred C57BL , Respiratory Distress Syndrome/pathology
5.
Methods Mol Biol ; 2099: 99-106, 2020.
Article in English | MEDLINE | ID: covidwho-1292548

ABSTRACT

Since the emergence of the Middle East respiratory syndrome-coronavirus (MERS-CoV) in 2012, more than 2280 confirmed human infections and 800 associated deaths had been reported to the World Health Organization. MERS-CoV is a single-stranded RNA virus that belongs to the Coronaviridae family. MERS-CoV infection leads to a variety of clinical outcomes in humans ranging from asymptomatic and mild infection to severe acute lung injury and multi-organ failure and death. To study the pathogenesis of MERS-CoV infection and development of medical countermeasures (MCMs) for MERS, a number of genetically modified mouse models have been developed, including various versions of transgenic mice expressing the human DPP4 viral receptor. Tracking and quantifying viral infection, among others, in permissive hosts is a key endpoint for studying MERS pathogenesis and evaluating the efficacy of selected MCMs developed for MERS. In addition to quantifying infectious progeny virus which requires high-containment biosafety level (BSL)-3 laboratory, here we outlined an established real-time quantitative RT-PCR (RT-qPCR)-based procedure to unequivocally quantify MERS-CoV-specific RNAs within the lungs of infected human DPP4 (hDPP4, transgenic (hDPP4 Tg) mice under a standard BSL-2 laboratory.


Subject(s)
Coronavirus Infections/virology , Middle East Respiratory Syndrome Coronavirus/genetics , RNA, Viral/analysis , Reverse Transcriptase Polymerase Chain Reaction/methods , Animals , Dipeptidyl Peptidase 4/genetics , Dipeptidyl Peptidase 4/metabolism , Disease Models, Animal , Humans , Lung/virology , Mice , Mice, Transgenic , Middle East Respiratory Syndrome Coronavirus/isolation & purification , Real-Time Polymerase Chain Reaction , Receptors, Virus/genetics , Receptors, Virus/metabolism
6.
J Allergy Clin Immunol ; 147(6): 2083-2097.e6, 2021 06.
Article in English | MEDLINE | ID: covidwho-1272498

ABSTRACT

BACKGROUND: Excessive inflammation triggered by a hitherto undescribed mechanism is a hallmark of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections and is associated with enhanced pathogenicity and mortality. OBJECTIVE: Complement hyperactivation promotes lung injury and was observed in patients suffering from Middle East respiratory syndrome-related coronavirus, SARS-CoV-1, and SARS-CoV-2 infections. Therefore, we investigated the very first interactions of primary human airway epithelial cells on exposure to SARS-CoV-2 in terms of complement component 3 (C3)-mediated effects. METHODS: For this, we used highly differentiated primary human 3-dimensional tissue models infected with SARS-CoV-2 patient isolates. On infection, viral load, viral infectivity, intracellular complement activation, inflammatory mechanisms, and tissue destruction were analyzed by real-time RT-PCR, high content screening, plaque assays, luminex analyses, and transepithelial electrical resistance measurements. RESULTS: Here, we show that primary normal human bronchial and small airway epithelial cells respond to SARS-CoV-2 infection by an inflated local C3 mobilization. SARS-CoV-2 infection resulted in exaggerated intracellular complement activation and destruction of the epithelial integrity in monolayer cultures of primary human airway cells and highly differentiated, pseudostratified, mucus-producing, ciliated respiratory tissue models. SARS-CoV-2-infected 3-dimensional cultures secreted significantly higher levels of C3a and the proinflammatory cytokines IL-6, monocyte chemoattractant protein 1, IL-1α, and RANTES. CONCLUSIONS: Crucially, we illustrate here for the first time that targeting the anaphylotoxin receptors C3a receptor and C5a receptor in nonimmune respiratory cells can prevent intrinsic lung inflammation and tissue damage. This opens up the exciting possibility in the treatment of COVID-19.


Subject(s)
Bronchi/immunology , COVID-19/immunology , Complement Activation , Epithelial Cells/immunology , Receptor, Anaphylatoxin C5a/immunology , Respiratory Mucosa/immunology , SARS-CoV-2/immunology , Bronchi/pathology , Bronchi/virology , COVID-19/pathology , COVID-19/virology , Cell Line , Complement C3/immunology , Cytokines/immunology , Epithelial Cells/pathology , Epithelial Cells/virology , Humans , Inflammation/immunology , Inflammation/pathology , Respiratory Mucosa/pathology , Respiratory Mucosa/virology
7.
Cells ; 10(6)2021 05 23.
Article in English | MEDLINE | ID: covidwho-1243956

ABSTRACT

The recent SARS-CoV-2 pandemic has refocused attention to the betacoronaviruses, only eight years after the emergence of another zoonotic betacoronavirus, the Middle East respiratory syndrome coronavirus (MERS-CoV). While the wild source of SARS-CoV-2 may be disputed, for MERS-CoV, dromedaries are considered as source of zoonotic human infections. Testing 100 immune-response genes in 121 dromedaries from United Arab Emirates (UAE) for potential association with present MERS-CoV infection, we identified candidate genes with important functions in the adaptive, MHC-class I (HLA-A-24-like) and II (HLA-DPB1-like), and innate immune response (PTPN4, MAGOHB), and in cilia coating the respiratory tract (DNAH7). Some of these genes previously have been associated with viral replication in SARS-CoV-1/-2 in humans, others have an important role in the movement of bronchial cilia. These results suggest similar host genetic pathways associated with these betacoronaviruses, although further work is required to better understand the MERS-CoV disease dynamics in both dromedaries and humans.


Subject(s)
Adaptive Immunity/genetics , Camelus/virology , Communicable Diseases, Emerging/immunology , Coronavirus Infections/immunology , Immunity, Innate/genetics , Zoonoses/immunology , Animals , Antibodies, Viral , Bronchi/cytology , Bronchi/physiology , COVID-19/genetics , COVID-19/immunology , COVID-19/virology , Camelus/genetics , Camelus/immunology , Cilia/physiology , Communicable Diseases, Emerging/genetics , Communicable Diseases, Emerging/transmission , Communicable Diseases, Emerging/virology , Coronavirus Infections/genetics , Coronavirus Infections/transmission , Coronavirus Infections/virology , Disease Reservoirs/virology , Female , Genetic Predisposition to Disease , Host Microbial Interactions/genetics , Host Microbial Interactions/immunology , Humans , Male , Middle East Respiratory Syndrome Coronavirus/immunology , Middle East Respiratory Syndrome Coronavirus/isolation & purification , Middle East Respiratory Syndrome Coronavirus/pathogenicity , Respiratory Mucosa/cytology , Respiratory Mucosa/physiology , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , United Arab Emirates , Virus Replication/genetics , Virus Replication/immunology , Zoonoses/genetics , Zoonoses/transmission , Zoonoses/virology
8.
PLoS Pathog ; 17(5): e1009229, 2021 05.
Article in English | MEDLINE | ID: covidwho-1239922

ABSTRACT

While MERS-CoV (Middle East respiratory syndrome Coronavirus) provokes a lethal disease in humans, camelids, the main virus reservoir, are asymptomatic carriers, suggesting a crucial role for innate immune responses in controlling the infection. Experimentally infected camelids clear infectious virus within one week and mount an effective adaptive immune response. Here, transcription of immune response genes was monitored in the respiratory tract of MERS-CoV infected alpacas. Concomitant to the peak of infection, occurring at 2 days post inoculation (dpi), type I and III interferons (IFNs) were maximally transcribed only in the nasal mucosa of alpacas, while interferon stimulated genes (ISGs) were induced along the whole respiratory tract. Simultaneous to mild focal infiltration of leukocytes in nasal mucosa and submucosa, upregulation of the anti-inflammatory cytokine IL10 and dampened transcription of pro-inflammatory genes under NF-κB control were observed. In the lung, early (1 dpi) transcription of chemokines (CCL2 and CCL3) correlated with a transient accumulation of mainly mononuclear leukocytes. A tight regulation of IFNs in lungs with expression of ISGs and controlled inflammatory responses, might contribute to virus clearance without causing tissue damage. Thus, the nasal mucosa, the main target of MERS-CoV in camelids, seems central in driving an efficient innate immune response based on triggering ISGs as well as the dual anti-inflammatory effects of type III IFNs and IL10.


Subject(s)
Camelids, New World , Coronavirus Infections/immunology , Interferon Type I/metabolism , Interferons/metabolism , Middle East Respiratory Syndrome Coronavirus/immunology , Animals , Antiviral Agents/metabolism , Antiviral Agents/pharmacology , Camelids, New World/immunology , Camelids, New World/metabolism , Camelids, New World/virology , Chlorocebus aethiops , Coronavirus Infections/metabolism , Coronavirus Infections/prevention & control , Coronavirus Infections/veterinary , Disease Reservoirs/veterinary , Disease Resistance/drug effects , Disease Resistance/genetics , Disease Resistance/immunology , Gene Expression Regulation , Immunity, Innate/physiology , Inflammation/immunology , Inflammation/metabolism , Inflammation/veterinary , Inflammation/virology , Interferon Type I/genetics , Interferon Type I/pharmacology , Interferons/genetics , Interferons/pharmacology , Middle East Respiratory Syndrome Coronavirus/drug effects , Middle East Respiratory Syndrome Coronavirus/physiology , Nasal Mucosa/drug effects , Nasal Mucosa/immunology , Nasal Mucosa/metabolism , Nasal Mucosa/virology , Respiratory System/drug effects , Respiratory System/immunology , Respiratory System/metabolism , Respiratory System/virology , Vero Cells , Viral Load/drug effects , Virus Replication/drug effects
9.
Comput Biol Med ; 134: 104451, 2021 07.
Article in English | MEDLINE | ID: covidwho-1237662

ABSTRACT

COVID-19, a global pandemic caused by an RNA virus named SARS-CoV-2 has brought the world to a standstill in terms of infectivity, casualty, and commercial plummet. RNA viruses can encode microRNAs (miRNAs) capable of modulating host gene expression, and with that notion, we aimed to predict viral miRNA like sequences of MERS-CoV, SARS-CoV and SARS-CoV-2, analyze sequence reciprocity and investigate SARS-CoV-2 encoded potential miRNA-human genes interaction using bioinformatics tools. In this study, we retrieved 206 SARS-CoV-2 genomes, executed phylogenetic analysis, and the selected reference genome (MT434792.1) exhibited about 99% similarities among the retrieved genomes. We predicted 402, 137, and 85 putative miRNAs of MERS-CoV (NC_019843.3), SARS-CoV (NC_004718.3), and SARS-CoV-2 (MT434792.1) genome, respectively. Sequence similarity was analyzed among 624 miRNAs which revealed that the predicted miRNAs of SARS-CoV-2 share a cluster with the clad of miRNAs from MERS-CoV and SARS-CoV. Only SARS-CoV-2 derived 85 miRNAs were encountered for target prediction and 29 viral miRNAs seemed to target 119 human genes. Moreover, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analysis suggested the involvement of respective genes in various pathways and biological processes. Finally, we focused on eight putative miRNAs influencing 14 genes that are involved in the adaptive hypoxic response, neuroinvasion and hormonal regulation, and tumorigenic progression in patients with COVID-19. SARS-CoV-2 encoded miRNAs may cause misexpression of some critical regulators and facilitate viral neuroinvasion, altered hormonal axis, and tumorigenic events in the human host. However, these propositions need validation from future studies.


Subject(s)
COVID-19 , MicroRNAs , Computer Simulation , Humans , MicroRNAs/genetics , Phylogeny , SARS-CoV-2
10.
Biomol NMR Assign ; 15(2): 341-345, 2021 10.
Article in English | MEDLINE | ID: covidwho-1220536

ABSTRACT

During the past 17 years, the coronaviruses have become a global public emergency, with the first appearance in 2012 in Saudi Arabia of the Middle East respiratory syndrome. Among the structural proteins encoded in the viral genome, the nucleocapsid protein is the most abundant in infected cells. It is a multifunctional phosphoprotein involved in the capsid formation, in the modulation and regulation of the viral life cycle. The N-terminal domain of N protein specifically interacts with transcriptional regulatory sequence (TRS) and is involved in the discontinuous transcription through the melting activity of double-stranded TRS (dsTRS).


Subject(s)
Middle East Respiratory Syndrome Coronavirus , Nuclear Magnetic Resonance, Biomolecular , Nucleocapsid Proteins/chemistry , Models, Molecular , Protein Domains
11.
J Med Virol ; 93(4): 2177-2195, 2021 04.
Article in English | MEDLINE | ID: covidwho-1217372

ABSTRACT

The emerged novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has created a global health crisis that warrants an accurate and detailed characterization of the rapidly evolving viral genome for understanding its epidemiology, pathogenesis, and containment. Here, we explored 61,485 sequences of the nucleocapsid (N) protein, a potent diagnostic and prophylactic target, for identifying the mutations to review their roles in real-time polymerase chain reaction based diagnosis and observe consequent impacts. Compared to the Wuhan reference strain, a total of 1034 unique nucleotide mutations were identified in the mutant strains (49.15%, n = 30,221) globally. Of these mutations, 367 occupy primer binding sites including the 3'-end mismatch to the primer-pair of 11 well-characterized primer sets. Noteworthily, CDC (USA) recommended the N2 primer set contained a lower mismatch than the other primer sets. Moreover, 684 amino acid (aa) substitutions were located across 317 (75.66% of total aa) unique positions including 82, 21, and 83 of those in the RNA binding N-terminal domain (NTD), SR-rich region, and C-terminal dimerization domain, respectively. Moreover, 11 in-frame deletions, mostly (n = 10) within the highly flexible linker region, were revealed, and the rest was within the NTD region. Furthermore, we predicted the possible consequence of high-frequency mutations (≥20) and deletions on the tertiary structure of the N protein. Remarkably, we observed that a high frequency (67.94% of mutated sequences) co-occuring mutations (R203K and G204R) destabilized and decreased overall structural flexibility. The N protein of SARS-CoV-2 comprises an average of 1.2 mutations per strain compared to 4.4 and 0.4 in Middle East respiratory syndrome-related coronavirus and SARS-CoV, respectively. Despite being proposed as the alternative target to spike protein for vaccine and therapeutics, the ongoing evolution of the N protein may challenge these endeavors, thus needing further immunoinformatics analyses. Therefore, continuous monitoring is required for tracing the ongoing evolution of the SARS-CoV-2 N protein in prophylactic and diagnostic interventions.


Subject(s)
Coronavirus Nucleocapsid Proteins/genetics , SARS-CoV-2/genetics , Amino Acid Substitution , COVID-19/epidemiology , COVID-19/virology , Coronavirus Nucleocapsid Proteins/chemistry , Coronavirus Nucleocapsid Proteins/metabolism , Evolution, Molecular , Genes, Viral , Genome, Viral , Molecular Dynamics Simulation , Mutation , Phosphoproteins/chemistry , Phosphoproteins/genetics , Phosphoproteins/metabolism , Protein Binding , Protein Conformation
12.
J Med Virol ; 93(1): 300-310, 2021 01.
Article in English | MEDLINE | ID: covidwho-1206791

ABSTRACT

The global pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), named coronavirus disease 2019, has infected more than 8.9 million people worldwide. This calls for urgent effective therapeutic measures. RNA-dependent RNA polymerase (RdRp) activity in viral transcription and replication has been recognized as an attractive target to design novel antiviral strategies. Although SARS-CoV-2 shares less genetic similarity with SARS-CoV (~79%) and Middle East respiratory syndrome coronavirus (~50%), the respective RdRps of the three coronaviruses are highly conserved, suggesting that RdRp is a good broad-spectrum antiviral target for coronaviruses. In this review, we discuss the antiviral potential of RdRp inhibitors (mainly nucleoside analogs) with an aim to provide a comprehensive account of drug discovery on SARS-CoV-2.


Subject(s)
Antiviral Agents/therapeutic use , COVID-19/drug therapy , COVID-19/virology , Enzyme Inhibitors/therapeutic use , RNA-Dependent RNA Polymerase/antagonists & inhibitors , SARS-CoV-2/enzymology , Antiviral Agents/pharmacology , Enzyme Inhibitors/pharmacology , Nucleosides/pharmacology , Nucleosides/therapeutic use , RNA-Dependent RNA Polymerase/genetics , RNA-Dependent RNA Polymerase/metabolism , SARS-CoV-2/metabolism
13.
J Immunol ; 206(11): 2566-2582, 2021 06 01.
Article in English | MEDLINE | ID: covidwho-1207829

ABSTRACT

Over the last two decades, there have been three deadly human outbreaks of coronaviruses (CoVs) caused by SARS-CoV, MERS-CoV, and SARS-CoV-2, which has caused the current COVID-19 global pandemic. All three deadly CoVs originated from bats and transmitted to humans via various intermediate animal reservoirs. It remains highly possible that other global COVID pandemics will emerge in the coming years caused by yet another spillover of a bat-derived SARS-like coronavirus (SL-CoV) into humans. Determining the Ag and the human B cells, CD4+ and CD8+ T cell epitope landscapes that are conserved among human and animal coronaviruses should inform in the development of future pan-coronavirus vaccines. In the current study, using several immunoinformatics and sequence alignment approaches, we identified several human B cell and CD4+ and CD8+ T cell epitopes that are highly conserved in 1) greater than 81,000 SARS-CoV-2 genome sequences identified in 190 countries on six continents; 2) six circulating CoVs that caused previous human outbreaks of the common cold; 3) nine SL-CoVs isolated from bats; 4) nine SL-CoV isolated from pangolins; 5) three SL-CoVs isolated from civet cats; and 6) four MERS strains isolated from camels. Furthermore, the identified epitopes: 1) recalled B cells and CD4+ and CD8+ T cells from both COVID-19 patients and healthy individuals who were never exposed to SARS-CoV-2, and 2) induced strong B cell and T cell responses in humanized HLA-DR1/HLA-A*02:01 double-transgenic mice. The findings pave the way to develop a preemptive multiepitope pan-coronavirus vaccine to protect against past, current, and future outbreaks.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Epitopes, T-Lymphocyte , Genome, Viral/immunology , Middle East Respiratory Syndrome Coronavirus , SARS Virus , SARS-CoV-2 , Adult , Aged , Aged, 80 and over , Animals , Epitopes, T-Lymphocyte/genetics , Epitopes, T-Lymphocyte/immunology , Female , Genome-Wide Association Study , Humans , Male , Middle Aged , Middle East Respiratory Syndrome Coronavirus/genetics , Middle East Respiratory Syndrome Coronavirus/immunology , SARS Virus/genetics , SARS Virus/immunology , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Viral Vaccines/genetics , Viral Vaccines/immunology
14.
Lancet Infect Dis ; 21(3): 385-395, 2021 03.
Article in English | MEDLINE | ID: covidwho-1162009

ABSTRACT

BACKGROUND: Middle East respiratory syndrome (MERS) remains of global public health concern. Dromedary camels are the source of zoonotic infection. Over 70% of MERS coronavirus (MERS-CoV)-infected dromedaries are found in Africa but no zoonotic disease has been reported in Africa. We aimed to understand whether individuals with exposure to dromedaries in Africa had been infected by MERS-CoV. METHODS: Workers slaughtering dromedaries in an abattoir in Kano, Nigeria, were compared with abattoir workers without direct dromedary contact, non-abattoir workers from Kano, and controls from Guangzhou, China. Exposure to dromedaries was ascertained using a questionnaire. Serum and peripheral blood mononuclear cells (PBMCs) were tested for MERS-CoV specific neutralising antibody and T-cell responses. FINDINGS: None of the participants from Nigeria or Guangdong were MERS-CoV seropositive. 18 (30%) of 61 abattoir workers with exposure to dromedaries, but none of 20 abattoir workers without exposure (p=0·0042), ten non-abattoir workers or 24 controls from Guangzhou (p=0·0002) had evidence of MERS-CoV-specific CD4+ or CD8+ T cells in PBMC. T-cell responses to other endemic human coronaviruses (229E, OC43, HKU-1, and NL-63) were observed in all groups with no association with dromedary exposure. Drinking both unpasteurised camel milk and camel urine was significantly and negatively associated with T-cell positivity (odds ratio 0·07, 95% CI 0·01-0·54). INTERPRETATION: Zoonotic infection of dromedary-exposed individuals is taking place in Nigeria and suggests that the extent of MERS-CoV infections in Africa is underestimated. MERS-CoV could therefore adapt to human transmission in Africa rather than the Arabian Peninsula, where attention is currently focused. FUNDING: The National Science and Technology Major Project, National Institutes of Health.


Subject(s)
Camelus/immunology , Coronavirus Infections/immunology , Coronavirus Infections/veterinary , Middle East Respiratory Syndrome Coronavirus/immunology , Occupational Exposure/statistics & numerical data , T-Lymphocytes/immunology , Zoonoses/epidemiology , Zoonoses/immunology , Adolescent , Adult , Aged , Animals , Antibodies, Neutralizing , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Camelus/virology , Cohort Studies , Coronavirus Infections/transmission , Female , Humans , Leukocytes, Mononuclear/immunology , Male , Middle Aged , Nigeria/epidemiology , Young Adult , Zoonoses/transmission , Zoonoses/virology
15.
J Biomol Struct Dyn ; : 1-10, 2021 Mar 22.
Article in English | MEDLINE | ID: covidwho-1145106

ABSTRACT

The recent outbreak of COVID-19 caused by a new human coronavirus called SARS-CoV-2, is continually causing worldwide human infections and deaths.The main protease (3CLpro), which plays a critical role in the life cycle of the virus, makes it an attractive target for the development of antiviral agents effective against coronaviruses (CoVs).Currently, there is no specific viral protein targeted therapeutics.Therefore, there is a need to investigate an alternative therapy which will prevent the spread of the infection, by focusing on the transmission of the virus.Chlorhexidine (CHX) and flavonoids agents have shown that they have a viral inactivation effect against enveloped viruses, and thus facilitate the struggle against oral transmission.Especially, some flavonoids have very strong antiviral activity in SARS-CoV and MERS-CoV main protease.This study was conducted to evaluate the CHX and flavonoids compounds potential antiviral effects on SARS-CoV-2 main protease through virtual screening for the COVID-19 treatment by molecular docking method.According to the results of this study, CHX, Kaempferol-3-rutinoside, Rutin, Quercetin 3-beta-D-glucoside and Isobavachalcone exhibited the best binding affinity against this enzyme, and also these compounds showed significant inhibitory effects compared to the SARS-CoV-2 main protease crystal structure inhibitor (N3).Especially, these compounds mainly interact with His41, Cys145, His163, Met165, Glu166 and Thr190 in SARS-CoV-2 main protease binding site. Further, MD simulation analysis also confirmed that stability of these interactions between the enzyme and these five compounds.The current study provides to guide clinical trials for broad-spectrum CHX and bioactive flavonoids to reduce the viral load of the infection and possibly disease progression.Communicated by Ramaswamy H. Sarma.

16.
Arch Immunol Ther Exp (Warsz) ; 69(1): 5, 2021 Mar 06.
Article in English | MEDLINE | ID: covidwho-1118194

ABSTRACT

Coronaviruses share conservative spike protein (S) on their enveloped membrane surface, where S1 subunit recognizes and binds the cellular receptor, and the S2 subunit mediates membrane fusion. This similarity raises the question: does coronaviral infection by one create protection to others? Convalescent SARS-CoV-2 (COVID-19) sera were tested for cross reactivity with peptides from Middle East respiratory syndrome coronavirus (MERS-CoV) which shares 74% homology. Our results showed significant cross-reactivity with a peptide of the heptad repeat 2 (HR2) domain of the MERS-CoV spike protein. Sera samples of 47 validated seropositive convalescent COVID-19 patients and 40 sera samples of control patients, collected in pre-COVID time were used to establish cross-bind reactivity with the MERS-CoV peptide. Significantly stronger binding (p < 0.0001) was observed for IgG antibodies in convalescent COVID-19 patients compared to the control group. In ELISA, MERS-CoV peptide helps to discriminate post-COVID-19 populations and non-infected ones by the presence of antibodies in blood samples. This suggests that polyclonal antibodies established during SARS-CoV-2 infection can recognize and probably decrease severity of MERS-CoV and other coronaviral infections. The high homology of the spike protein domain also suggests that the opposite effect can be true: coronaviral infections produce cross-reactive antibodies effective against SARS-CoV-2. The collected data prove that despite the core HR2 region is hidden in the native viral conformation, its exposure during cell entry makes it highly immunogenic. Since inhibitory peptides to this region were previously described, this opens new possibilities in fighting coronaviral infections and developing vaccines effective even after possible viral mutations.


Subject(s)
Antibodies, Viral/immunology , COVID-19/immunology , Convalescence , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Cross Reactions , Humans , Middle East Respiratory Syndrome Coronavirus/immunology , SARS Virus/immunology
17.
PeerJ ; 9: e11008, 2021.
Article in English | MEDLINE | ID: covidwho-1102635

ABSTRACT

BACKGROUND: The innate immune system especially Toll-like receptor (TLR) 7/8 and the interferon pathway, constitutes an important first line of defense against single-stranded RNA viruses. However, large-scale, systematic comparisons of the TLR 7/8-stimulating potential of genomic RNAs of single-stranded RNA viruses are rare. In this study, a computational method to evaluate the human TLR 7/8-stimulating ability of single-stranded RNA virus genomes based on their human TLR 7/8-stimulating trimer compositions was used to analyze 1,002 human coronavirus genomes. RESULTS: The human TLR 7/8-stimulating potential of coronavirus genomic (positive strand) RNAs followed the order of NL63-CoV > HKU1-CoV >229E-CoV ≅ OC63-CoV > SARS-CoV-2 > MERS-CoV > SARS-CoV. These results suggest that among these coronaviruses, MERS-CoV, SARS-CoV and SARS-CoV-2 may have a higher ability to evade the human TLR 7/8-mediated innate immune response. Analysis with a logistic regression equation derived from human coronavirus data revealed that most of the 1,762 coronavirus genomic (positive strand) RNAs isolated from bats, camels, cats, civets, dogs and birds exhibited weak human TLR 7/8-stimulating potential equivalent to that of the MERS-CoV, SARS-CoV and SARS-CoV-2 genomic RNAs. CONCLUSIONS: Prediction of the human TLR 7/8-stimulating potential of viral genomic RNAs may be useful for surveillance of emerging coronaviruses from nonhuman mammalian hosts.

18.
Virus Evol ; 7(1): veab014, 2021 Jan.
Article in English | MEDLINE | ID: covidwho-1093600

ABSTRACT

The coronavirus, Severe Acute Respiratory Syndrome (SARS)-CoV-2, responsible for the ongoing coronavirus disease 2019 (COVID-19) pandemic, has emphasized the need for a better understanding of the evolution of virus-host interactions. ORF3a in both SARS-CoV-1 and SARS-CoV-2 are ion channels (viroporins) implicated in virion assembly and membrane budding. Using sensitive profile-based homology detection methods, we unify the SARS-CoV ORF3a family with several families of viral proteins, including ORF5 from MERS-CoVs, proteins from beta-CoVs (ORF3c), alpha-CoVs (ORF3b), most importantly, the Matrix (M) proteins from CoVs, and more distant homologs from other nidoviruses. We present computational evidence that these viral families might utilize specific conserved polar residues to constitute an aqueous pore within the membrane-spanning region. We reconstruct an evolutionary history of these families and objectively establish the common origin of the M proteins of CoVs and Toroviruses. We also show that the divergent ORF3 clade (ORF3a/ORF3b/ORF3c/ORF5 families) represents a duplication stemming from the M protein in alpha- and beta-CoVs. By phyletic profiling of major structural components of primary nidoviruses, we present a hypothesis for their role in virion assembly of CoVs, ToroVs, and Arteriviruses. The unification of diverse M/ORF3 ion channel families in a wide range of nidoviruses, especially the typical M protein in CoVs, reveal a conserved, previously under-appreciated role of ion channels in virion assembly and membrane budding. We show that M and ORF3 are under different evolutionary pressures; in contrast to the slow evolution of M as core structural component, the ORF3 clade is under selection for diversification, which suggests it might act at the interface with host molecules and/or immune attack.

19.
Rev Peru Med Exp Salud Publica ; 37(4): 746-754, 2020.
Article in Spanish | MEDLINE | ID: covidwho-1076937

ABSTRACT

There is currently no vaccine available and no specific medication against Coronavirus 2019 disease (COVID-19). The treatment is mainly based on support measures. In this context, several potentially useful therapies have been approved for use in clinical trials, such as convalescent plasma transfusion (CPT). PubMed was searched for studies on convalescent plasma and COVID-19, SARS or MERS. Studies on clinical efficacy in diseases caused by other coronaviruses (SARS-CoV and MERS-CoV) showed clinical improvement, increase of neutralizing antibodies, decreased mortality and absence of adverse events during and after treatment. We found 13 studies on this type of treatment used in patients with severe and critical COVID-19. Despite limitations regarding methodology, number of patients and the protocols for the analysis of donors' convalescent plasma, patients who received CPT showed clinical improvement, improvement of ventilatory patterns, resolution of lung injuries, decreased mortality, improvement of laboratory parameters, increase of neutralizing antibodies, decreased viral load and low frequency of adverse events.


Actualmente no existe vacuna disponible ni medicación específica contra la enfermedad por coronavirus 2019 (COVID-19). El tratamiento se basa fundamentalmente en medidas de soporte. En este contexto, se han aprobado múltiples terapias de potencial utilidad para su uso en ensayos clínicos, como la transfusión de plasma convaleciente (TPC). Se realizó una búsqueda en PubMed de estudios sobre plasma convaleciente y COVID-19, SARS o MERS. Los estudios sobre la eficacia clínica en enfermedades causadas por otros coronavirus (SARS-CoV y MERS-CoV) evidenciaron mejoría clínica, aumento de anticuerpos neutralizantes, disminución de la mortalidad y ausencia de eventos adversos durante y después del tratamiento. En el caso de la COVID-19, se encontraron 13 estudios en pacientes con la COVID-19 grave y crítica. Aunque existen limitaciones en la metodología, en el número de pacientes y en los protocolos para el análisis del plasma convaleciente de los donantes, los pacientes que recibieron TPC evidenciaron mejoría clínica, mejoría de patrones ventilatorios, resolución de lesiones pulmonares, disminución de mortalidad, mejoría de parámetros laboratoriales, aumento de anticuerpos neutralizantes, disminución de carga viral y baja frecuencia de eventos adversos.


Subject(s)
Antibodies, Neutralizing/immunology , COVID-19/therapy , Blood Component Transfusion/methods , COVID-19/immunology , COVID-19/mortality , Humans , Immunization, Passive/adverse effects , Immunization, Passive/methods , Severity of Illness Index , Treatment Outcome , Viral Load/immunology
20.
Front Plant Sci ; 11: 604663, 2020.
Article in English | MEDLINE | ID: covidwho-1054993

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease (COVID-19) which has recently emerged as a potential threat to global public health. SARS-CoV-2 is the third known human coronavirus that has huge impact on the human population after SARS-CoV and MERS-CoV. Although some vaccines and therapeutic drugs are currently in clinical trials, none of them are approved for commercial use yet. As with SARS-CoV, SARS-CoV-2 utilizes angiotensin-converting enzyme 2 (ACE2) as the cell entry receptor to enter into the host cell. In this study, we have transiently produced human ACE2 fused with the Fc region of human IgG1 in Nicotiana benthamiana and the in vitro neutralization efficacy of the plant-produced ACE2-Fc fusion protein was assessed. The recombinant ACE2-Fc fusion protein was expressed in N. benthamiana at 100 µg/g leaf fresh weight on day 6 post-infiltration. The recombinant fusion protein showed potent binding to receptor binding domain (RBD) of SARS-CoV-2. Importantly, the plant-produced fusion protein exhibited potent anti-SARS-CoV-2 activity in vitro. Treatment with ACE2-Fc fusion protein after viral infection dramatically inhibit SARS-CoV-2 infectivity in Vero cells with an IC50 value of 0.84 µg/ml. Moreover, treatment with ACE2-Fc fusion protein at the pre-entry stage suppressed SARS-CoV-2 infection with an IC50 of 94.66 µg/ml. These findings put a spotlight on the plant-produced ACE2-Fc fusion protein as a potential therapeutic candidate against SARS-CoV-2.

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