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1.
STAR Protoc ; 3(1): 101067, 2022 03 18.
Article in English | MEDLINE | ID: covidwho-1595326

ABSTRACT

N 6 -methylation of adenosine (m6A) is the most abundant internal mRNA modification and is an important post-transcriptional regulator of gene expression. Here, we describe a protocol for methylated RNA immunoprecipitation sequencing (MeRIP-Seq) to detect and quantify m6A modifications in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA. The protocol is optimized for low viral RNA levels and is readily adaptable for other applications. For complete details on the use and execution of this protocol, please refer to Li et al. (2021).


Subject(s)
Adenosine/analogs & derivatives , Immunoprecipitation/methods , Sequence Analysis, RNA/methods , Adenosine/analysis , Adenosine/genetics , Animals , COVID-19/genetics , Caco-2 Cells , Chlorocebus aethiops , Gene Expression/genetics , Gene Expression Regulation/genetics , Genetic Techniques , HEK293 Cells , Humans , Methylation , RNA/chemistry , RNA/genetics , RNA Processing, Post-Transcriptional , RNA, Viral/metabolism , SARS-CoV-2/genetics , SARS-CoV-2/pathogenicity , Vero Cells
2.
Signal Transduct Target Ther ; 6(1): 420, 2021 12 14.
Article in English | MEDLINE | ID: covidwho-1585885

ABSTRACT

COVID-19 is identified as a zoonotic disease caused by SARS-CoV-2, which also can cross-transmit to many animals but not mice. Genetic modifications of SARS-CoV-2 or mice enable the mice susceptible to viral infection. Although neither is the natural situation, they are currently utilized to establish mouse infection models. Here we report a direct contact transmission of SARS-CoV-2 variant B.1.351 in wild-type mice. The SARS-CoV-2 (B.1.351) replicated efficiently and induced significant pathological changes in lungs and tracheas, accompanied by elevated proinflammatory cytokines in the lungs and sera. Mechanistically, the receptor-binding domain (RBD) of SARS-CoV-2 (B.1.351) spike protein turned to a high binding affinity to mouse angiotensin-converting enzyme 2 (mACE2), allowing the mice highly susceptible to SARS-CoV-2 (B.1.351) infection. Our work suggests that SARS-CoV-2 (B.1.351) expands the host range and therefore increases its transmission route without adapted mutation. As the wild house mice live with human populations quite closely, this possible transmission route could be potentially risky. In addition, because SARS-CoV-2 (B.1.351) is one of the major epidemic strains and the mACE2 in laboratory-used mice is naturally expressed and regulated, the SARS-CoV-2 (B.1.351)/mice could be a much convenient animal model system to study COVID-19 pathogenesis and evaluate antiviral inhibitors and vaccines.


Subject(s)
Angiotensin-Converting Enzyme 2/genetics , COVID-19/transmission , Host-Pathogen Interactions/genetics , Receptors, Virus/genetics , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/genetics , Angiotensin-Converting Enzyme 2/immunology , Animals , COVID-19/immunology , COVID-19/virology , Cytokines/genetics , Cytokines/immunology , Disease Models, Animal , Gene Expression , HEK293 Cells , Host-Pathogen Interactions/immunology , Humans , Lung/pathology , Lung/virology , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Protein Binding , Protein Domains , Receptors, Virus/immunology , SARS-CoV-2/classification , SARS-CoV-2/genetics , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/immunology , Virus Replication
3.
Int J Mol Sci ; 22(24)2021 Dec 19.
Article in English | MEDLINE | ID: covidwho-1580688

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) triggered the pandemic Coronavirus Disease 19 (COVID-19), causing millions of deaths. The elderly and those already living with comorbidity are likely to die after SARS-CoV-2 infection. People suffering from Alzheimer's disease (AD) have a higher risk of becoming infected, because they cannot easily follow health roles. Additionally, those suffering from dementia have a 40% higher risk of dying from COVID-19. Herein, we collected from Gene Expression Omnibus repository the brain samples of AD patients who died of COVID-19 (AD+COVID-19), AD without COVID-19 (AD), COVID-19 without AD (COVID-19) and control individuals. We inspected the transcriptomic and interactomic profiles by comparing the COVID-19 cohort against the control cohort and the AD cohort against the AD+COVID-19 cohort. SARS-CoV-2 in patients without AD mainly activated processes related to immune response and cell cycle. Conversely, 21 key nodes in the interactome are deregulated in AD. Interestingly, some of them are linked to beta-amyloid production and clearance. Thus, we inspected their role, along with their interactors, using the gene ontologies of the biological process that reveals their contribution in brain organization, immune response, oxidative stress and viral replication. We conclude that SARS-CoV-2 worsens the AD condition by increasing neurotoxicity, due to higher levels of beta-amyloid, inflammation and oxidative stress.


Subject(s)
Alzheimer Disease/genetics , COVID-19/complications , COVID-19/genetics , Alzheimer Disease/complications , Alzheimer Disease/virology , Amyloid beta-Peptides/metabolism , Brain/virology , COVID-19/physiopathology , Comorbidity/trends , Databases, Factual , Gene Expression/genetics , Gene Expression Profiling/methods , Humans , Inflammation/metabolism , Neurotoxicity Syndromes/metabolism , Oxidative Stress/physiology , Pandemics , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity , Transcriptome/genetics
4.
Rev Med Virol ; 31(6): e2231, 2021 11.
Article in English | MEDLINE | ID: covidwho-1574317

ABSTRACT

The Spike protein is the target of both antibody-based therapeutics (convalescent plasma, polyclonal serum, monoclonal antibodies) and vaccines. Mutations in Spike could affect efficacy of those treatments. Hence, monitoring of mutations is necessary to forecast and readapt the inventory of therapeutics. Different phylogenetic nomenclatures have been used for the currently circulating SARS-CoV-2 clades. The Spike protein has different hotspots of mutation and deletion, the most dangerous for immune escape being the ones within the receptor binding domain (RBD), such as K417N/T, N439K, L452R, Y453F, S477N, E484K, and N501Y. Convergent evolution has led to different combinations of mutations among different clades. In this review we focus on the main variants of concern, that is, the so-called UK (B.1.1.7), South African (B.1.351) and Brazilian (P.1) strains.


Subject(s)
Antibodies, Monoclonal/therapeutic use , Antibodies, Neutralizing/therapeutic use , COVID-19/therapy , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Antibodies, Monoclonal/chemistry , Antibodies, Monoclonal/metabolism , Antibodies, Neutralizing/chemistry , Antibodies, Neutralizing/metabolism , Antibodies, Viral/chemistry , Antibodies, Viral/metabolism , Antibodies, Viral/therapeutic use , Brazil/epidemiology , COVID-19/epidemiology , COVID-19/immunology , COVID-19/virology , COVID-19 Vaccines/administration & dosage , Gene Expression , Humans , Immune Evasion , Immunization, Passive/methods , Mutation , Phylogeny , Protein Binding , Risk Assessment , SARS-CoV-2/classification , SARS-CoV-2/drug effects , SARS-CoV-2/immunology , South Africa/epidemiology , Spike Glycoprotein, Coronavirus/immunology , United Kingdom/epidemiology
5.
Rev Med Virol ; 31(6): e2234, 2021 11.
Article in English | MEDLINE | ID: covidwho-1574124

ABSTRACT

The coronavirus disease (Covid-19) pandemic is the most serious event of the year 2020, causing considerable global morbidity and mortality. The goal of this review is to provide a comprehensive summary of reported associations between inter-individual immunogenic variants and disease susceptibility or symptoms caused by the coronavirus strains severe acute respiratory syndrome-associated coronavirus, severe acute respiratory syndrome-associated coronavirus-2, and two of the main respiratory viruses, respiratory syncytial virus and influenza virus. The results suggest that the genetic background of the host could affect the levels of proinflammatory and anti-inflammatory cytokines and might modulate the progression of Covid-19 in affected patients. Notably, genetic variations in innate immune components such as toll-like receptors and mannose-binding lectin 2 play critical roles in the ability of the immune system to recognize coronavirus and initiate an early immune response to clear the virus and prevent the development of severe symptoms. This review provides promising clues related to the potential benefits of using immunotherapy and immune modulation for respiratory infectious disease treatment in a personalized manner.


Subject(s)
COVID-19/immunology , Cytokine Release Syndrome/immunology , Genetic Predisposition to Disease , Influenza, Human/immunology , Respiratory Syncytial Virus Infections/immunology , Severe Acute Respiratory Syndrome/immunology , Antiviral Agents/therapeutic use , Biological Variation, Individual , COVID-19/drug therapy , COVID-19/genetics , COVID-19/virology , Cytokine Release Syndrome/drug therapy , Cytokine Release Syndrome/genetics , Cytokine Release Syndrome/virology , Gene Expression , Humans , Immunity, Innate , Immunologic Factors/therapeutic use , Influenza, Human/drug therapy , Influenza, Human/genetics , Influenza, Human/virology , Mannose-Binding Lectin/genetics , Mannose-Binding Lectin/immunology , Orthomyxoviridae/drug effects , Orthomyxoviridae/immunology , Respiratory Syncytial Virus Infections/drug therapy , Respiratory Syncytial Virus Infections/genetics , Respiratory Syncytial Virus Infections/virology , Respiratory Syncytial Viruses/drug effects , Respiratory Syncytial Viruses/immunology , SARS Virus/drug effects , SARS Virus/immunology , SARS-CoV-2/classification , SARS-CoV-2/drug effects , SARS-CoV-2/immunology , Severe Acute Respiratory Syndrome/drug therapy , Severe Acute Respiratory Syndrome/genetics , Severe Acute Respiratory Syndrome/virology , Toll-Like Receptors/genetics , Toll-Like Receptors/immunology
6.
Rev Med Virol ; 31(6): e2236, 2021 11.
Article in English | MEDLINE | ID: covidwho-1573896

ABSTRACT

Modifications in HLA-I expression are found in many viral diseases. They represent one of the immune evasion strategies most widely used by viruses to block antigen presentation and NK cell response, and SARS-CoV-2 is no exception. These alterations result from a combination of virus-specific factors, genetically encoded mechanisms, and the status of host defences and range from loss or upregulation of HLA-I molecules to selective increases of HLA-I alleles. In this review, I will first analyse characteristic features of altered HLA-I expression found in SARS-CoV-2. I will then discuss the potential factors underlying these defects, focussing on HLA-E and class-I-related (like) molecules and their receptors, the most documented HLA-I alterations. I will also draw attention to potential differences between cells transfected to express viral proteins and those presented as part of authentic infection. Consideration of these factors and others affecting HLA-I expression may provide us with improved possibilities for research into cellular immunity against viral variants.


Subject(s)
Antigenic Variation , COVID-19/immunology , Clonal Anergy , Histocompatibility Antigens Class I/immunology , Immune Evasion , SARS-CoV-2/genetics , Alleles , COVID-19/pathology , COVID-19/virology , Cytokines/genetics , Cytokines/immunology , Cytotoxicity, Immunologic , Gene Expression , Histocompatibility Antigens Class I/genetics , Humans , Immunity, Cellular , Killer Cells, Natural/immunology , Killer Cells, Natural/virology , NK Cell Lectin-Like Receptor Subfamily C/genetics , NK Cell Lectin-Like Receptor Subfamily C/immunology , NK Cell Lectin-Like Receptor Subfamily D/genetics , NK Cell Lectin-Like Receptor Subfamily D/immunology , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , T-Lymphocytes, Cytotoxic/immunology , T-Lymphocytes, Cytotoxic/virology
7.
Epigenetics Chromatin ; 14(1): 54, 2021 12 11.
Article in English | MEDLINE | ID: covidwho-1571923

ABSTRACT

BACKGROUND: Understanding the molecular basis of susceptibility factors to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is a global health imperative. It is well-established that males are more likely to acquire SARS-CoV-2 infection and exhibit more severe outcomes. Similarly, exposure to air pollutants and pre-existing respiratory chronic conditions, such as asthma and chronic obstructive respiratory disease (COPD) confer an increased risk to coronavirus disease 2019 (COVID-19). METHODS: We investigated molecular patterns associated with risk factors in 398 candidate genes relevant to COVID-19 biology. To accomplish this, we downloaded DNA methylation and gene expression data sets from publicly available repositories (GEO and GTEx Portal) and utilized data from an empirical controlled human exposure study conducted by our team. RESULTS: First, we observed sex-biased DNA methylation patterns in autosomal immune genes, such as NLRP2, TLE1, GPX1, and ARRB2 (FDR < 0.05, magnitude of DNA methylation difference Δß > 0.05). Second, our analysis on the X-linked genes identified sex associated DNA methylation profiles in genes, such as ACE2, CA5B, and HS6ST2 (FDR < 0.05, Δß > 0.05). These associations were observed across multiple respiratory tissues (lung, nasal epithelia, airway epithelia, and bronchoalveolar lavage) and in whole blood. Some of these genes, such as NLRP2 and CA5B, also exhibited sex-biased gene expression patterns. In addition, we found differential DNA methylation patterns by COVID-19 status for genes, such as NLRP2 and ACE2 in an exploratory analysis of an empirical data set reporting on human COVID-9 infections. Third, we identified modest DNA methylation changes in CpGs associated with PRIM2 and TATDN1 (FDR < 0.1, Δß > 0.05) in response to particle-depleted diesel exhaust in bronchoalveolar lavage. Finally, we captured a DNA methylation signature associated with COPD diagnosis in a gene involved in nicotine dependence (COMT) (FDR < 0.1, Δß > 0.05). CONCLUSION: Our findings on sex differences might be of clinical relevance given that they revealed molecular associations of sex-biased differences in COVID-19. Specifically, our results hinted at a potentially exaggerated immune response in males linked to autosomal genes, such as NLRP2. In contrast, our findings at X-linked loci such as ACE2 suggested a potentially distinct DNA methylation pattern in females that may interact with its mRNA expression and inactivation status. We also found tissue-specific DNA methylation differences in response to particulate exposure potentially capturing a nitrogen dioxide (NO2) effect-a contributor to COVID-19 susceptibility. While we identified a molecular signature associated with COPD, all COPD-affected individuals were smokers, which may either reflect an association with the disease, smoking, or may highlight a compounded effect of these two risk factors in COVID-19. Overall, our findings point towards a molecular basis of variation in susceptibility factors that may partly explain disparities in the risk for SARS-CoV-2 infection.


Subject(s)
COVID-19/genetics , DNA Methylation , Gene Expression , SARS-CoV-2 , Sex Characteristics , Adaptor Proteins, Signal Transducing/genetics , Adolescent , Adult , Air Pollutants/adverse effects , Angiotensin-Converting Enzyme 2/genetics , Apoptosis Regulatory Proteins/genetics , COVID-19/virology , Child , Child, Preschool , Chromosomes, Human, X , Co-Repressor Proteins/genetics , Female , Genes, X-Linked , Glutathione Peroxidase/genetics , Humans , Infant , Infant, Newborn , Male , Middle Aged , Risk Factors , Smoking/adverse effects , Sulfotransferases/genetics , Young Adult , beta-Arrestin 2/genetics
8.
Int J Mol Sci ; 22(24)2021 Dec 07.
Article in English | MEDLINE | ID: covidwho-1554804

ABSTRACT

In the last few years, microRNA-mediated regulation has been shown to be important in viral infections. In fact, viral microRNAs can alter cell physiology and act on the immune system; moreover, cellular microRNAs can regulate the virus cycle, influencing positively or negatively viral replication. Accordingly, microRNAs can represent diagnostic and prognostic biomarkers of infectious processes and a promising approach for designing targeted therapies. In the past 18 months, the COVID-19 infection from SARS-CoV-2 has engaged many researchers in the search for diagnostic and prognostic markers and the development of therapies. Although some research suggests that the SARS-CoV-2 genome can produce microRNAs and that host microRNAs may be involved in the cellular response to the virus, to date, not enough evidence has been provided. In this paper, using a focused bioinformatic approach exploring the SARS-CoV-2 genome, we propose that SARS-CoV-2 is able to produce microRNAs sharing a strong sequence homology with the human ones and also that human microRNAs may target viral RNA regulating the virus life cycle inside human cells. Interestingly, all viral miRNA sequences and some human miRNA target sites are conserved in more recent SARS-CoV-2 variants of concern (VOCs). Even if experimental evidence will be needed, in silico analysis represents a valuable source of information useful to understand the sophisticated molecular mechanisms of disease and to sustain biomedical applications.


Subject(s)
MicroRNAs/genetics , SARS-CoV-2/genetics , Virus Replication/genetics , COVID-19/genetics , Computational Biology/methods , DNA Viruses/genetics , Gene Expression/genetics , Gene Expression Regulation, Viral/genetics , Genome, Viral/genetics , Host-Pathogen Interactions/genetics , RNA, Viral/genetics , Sequence Homology
9.
Biomolecules ; 11(12)2021 12 02.
Article in English | MEDLINE | ID: covidwho-1551563

ABSTRACT

COVID-19 is a highly infectious disease caused by a newly emerged coronavirus (SARS-CoV-2) that has rapidly progressed into a pandemic. This unprecedent emergency has stressed the significance of developing effective therapeutics to fight the current and future outbreaks. The receptor-binding domain (RBD) of the SARS-CoV-2 surface Spike protein is the main target for vaccines and represents a helpful "tool" to produce neutralizing antibodies or diagnostic kits. In this work, we provide a detailed characterization of the native RBD produced in three major model systems: Escherichia coli, insect and HEK-293 cells. Circular dichroism, gel filtration chromatography and thermal denaturation experiments indicated that recombinant SARS-CoV-2 RBD proteins are stable and correctly folded. In addition, their functionality and receptor-binding ability were further evaluated through ELISA, flow cytometry assays and bio-layer interferometry.


Subject(s)
COVID-19/metabolism , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Animals , Cell Line , Escherichia coli/genetics , Gene Expression , HEK293 Cells , Humans , Insecta/cytology , Protein Binding , Protein Denaturation , Protein Domains , Protein Folding , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , SARS-CoV-2/chemistry , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics
11.
J Mol Model ; 27(11): 323, 2021 Oct 13.
Article in English | MEDLINE | ID: covidwho-1525539

ABSTRACT

The world has face the COVID-19 pandemic which has already caused millions of death. Due to the urgency in fighting the virus, we study five residues of free amino acids present in the structure of the SARS-CoV-2 spike protein (S). We investigated the spontaneous interaction between amino acids and silver ions (Ag+), considering these ions as a virucide chemical agent for SARS-CoV-2. The amino acid-Ag+ systems were investigated in a gaseous medium and a simulated water environment was described with a continuum model (PCM) the calculations were performed within the framework of density functional theory (DFT). Calculations related to the occupied orbitals of higher energy showed that Ag+ has a tendency to interact with the nitrile groups (-NH). The negative values of the Gibbs free energies show that the interaction process between amino acids-Ag+ in both media occurs spontaneously. There is a decrease in Gibbs free energy from the amino acid-Ag+ interactions immersed in a water solvation simulator.


Subject(s)
Amino Acids/chemistry , Antiviral Agents/chemistry , Density Functional Theory , Silver/chemistry , Spike Glycoprotein, Coronavirus/chemistry , Amino Acids/metabolism , Antiviral Agents/metabolism , Binding Sites , Cations, Monovalent , Gene Expression , Humans , Protein Binding , Protein Conformation, alpha-Helical , Protein Conformation, beta-Strand , Protein Interaction Domains and Motifs , SARS-CoV-2/chemistry , Silver/metabolism , Spike Glycoprotein, Coronavirus/antagonists & inhibitors , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism , Static Electricity , Thermodynamics
12.
Cell Rep ; 37(7): 110020, 2021 11 16.
Article in English | MEDLINE | ID: covidwho-1509641

ABSTRACT

Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component. Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci (eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene), including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types.


Subject(s)
COVID-19/genetics , SARS-CoV-2/genetics , Chromosome Mapping/methods , Computational Biology/methods , Databases, Genetic , Gene Expression/genetics , Gene Expression Profiling/methods , Genetic Predisposition to Disease/genetics , Genetic Variation/genetics , Genome-Wide Association Study/methods , Humans , Organ Specificity/genetics , Polymorphism, Single Nucleotide/genetics , Quantitative Trait Loci/genetics , SARS-CoV-2/pathogenicity , Severity of Illness Index , Transcriptome/genetics
13.
J Virol ; 95(16): e0061721, 2021 07 26.
Article in English | MEDLINE | ID: covidwho-1486509

ABSTRACT

The current pandemic of COVID-19 is caused by a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The SARS-CoV-2 spike protein receptor-binding domain (RBD) is the critical determinant of viral tropism and infectivity. To investigate whether naturally occurring RBD mutations during the early transmission phase have altered the receptor binding affinity and infectivity, we first analyzed in silico the binding dynamics between SARS-CoV-2 RBD mutants and the human angiotensin-converting enzyme 2 (ACE2) receptor. Among 32,123 genomes of SARS-CoV-2 isolates (December 2019 through March 2020), 302 nonsynonymous RBD mutants were identified and clustered into 96 mutant types. The six dominant mutations were analyzed applying molecular dynamics simulations (MDS). The mutant type V367F continuously circulating worldwide displayed higher binding affinity to human ACE2 due to the enhanced structural stabilization of the RBD beta-sheet scaffold. The MDS also indicated that it would be difficult for bat SARS-like CoV to infect humans. However, the pangolin CoV is potentially infectious to humans. The increased infectivity of V367 mutants was further validated by performing receptor-ligand binding enzyme-linked immunosorbent assay (ELISA), surface plasmon resonance, and pseudotyped virus assays. Phylogenetic analysis of the genomes of V367F mutants showed that during the early transmission phase, most V367F mutants clustered more closely with the SARS-CoV-2 prototype strain than the dual-mutation variants (V367F+D614G), which may derivate from recombination. The analysis of critical RBD mutations provides further insights into the evolutionary trajectory of early SARS-CoV-2 variants of zoonotic origin under negative selection pressure and supports the continuing surveillance of spike mutations to aid in the development of new COVID-19 drugs and vaccines. IMPORTANCE A novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused the pandemic of COVID-19. The origin of SARS-CoV-2 was associated with zoonotic infections. The spike protein receptor-binding domain (RBD) is identified as the critical determinant of viral tropism and infectivity. Thus, whether mutations in the RBD of the circulating SARS-CoV-2 isolates have altered the receptor binding affinity and made them more infectious has been the research hot spot. Given that SARS-CoV-2 is a novel coronavirus, the significance of our research is in identifying and validating the RBD mutant types emerging during the early transmission phase and increasing human angiotensin-converting enzyme 2 (ACE2) receptor binding affinity and infectivity. Our study provides insights into the evolutionary trajectory of early SARS-CoV-2 variants of zoonotic origin. The continuing surveillance of RBD mutations with increased human ACE2 affinity in human or other animals is critical to the development of new COVID-19 drugs and vaccines against these variants during the sustained COVID-19 pandemic.


Subject(s)
Amino Acid Substitution , Angiotensin-Converting Enzyme 2/genetics , COVID-19/transmission , Mutation , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Angiotensin-Converting Enzyme 2/chemistry , Angiotensin-Converting Enzyme 2/metabolism , Binding Sites , COVID-19/pathology , COVID-19/virology , Gene Expression , Host-Pathogen Interactions/genetics , Humans , Kinetics , Molecular Dynamics Simulation , Phenylalanine/chemistry , Phenylalanine/metabolism , Phylogeny , Protein Binding , Protein Conformation, alpha-Helical , Protein Conformation, beta-Strand , Protein Interaction Domains and Motifs , SARS-CoV-2/classification , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/metabolism , Thermodynamics , Valine/chemistry , Valine/metabolism , Virulence , Virus Attachment
14.
Physiol Rep ; 9(20): e15075, 2021 10.
Article in English | MEDLINE | ID: covidwho-1485552

ABSTRACT

Exercise has substantial health benefits, but the effects of exercise on immune status and susceptibility to respiratory infections are less clear. Furthermore, there is limited research examining the effects of prolonged exercise on local respiratory immunity and antiviral activity. To assess the upper respiratory tract in response to exercise, we collected nasal lavage fluid (NALF) from human subjects (1) at rest, (2) after 45 min of moderate-intensity exercise, and (3) after 180 min of moderate-intensity exercise. To assess immune responses of the lower respiratory tract, we utilized a murine model to examine the effect of exercise duration on bronchoalveolar lavage (BAL) fluid immune cell content and lung gene expression. NALF cell counts did not change after 45 min of exercise, whereas 180 min significantly increased total cells and leukocytes in NALF. Importantly, fold change in NALF leukocytes correlated with the post-exercise fatigue rating in the 180-min exercise condition. The acellular portion of NALF contained strong antiviral activity against Influenza A in both resting and exercise paradigms. In mice undergoing moderate-intensity exercise, BAL total cells and neutrophils decreased in response to 45 or 90 min of exercise. In lung lobes, increased expression of heat shock proteins suggested that cellular stress occurred in response to exercise. However, a broad upregulation of inflammatory genes was not observed, even at 180 min of exercise. This work demonstrates that exercise duration differentially alters the cellularity of respiratory tract fluids, antiviral activity, and gene expression. These changes in local mucosal immunity may influence resistance to respiratory viruses, including influenza or possibly other pathogens in which nasal mucosa plays a protective role, such as rhinovirus or SARS-CoV-2.


Subject(s)
Exercise/physiology , Influenza A virus/immunology , Leukocytes/immunology , Lung/immunology , Nasal Lavage Fluid/immunology , Neutrophils/immunology , Adolescent , Adult , Animals , Bronchoalveolar Lavage Fluid/cytology , Bronchoalveolar Lavage Fluid/immunology , Female , Gene Expression , Humans , Leukocytes/metabolism , Lung/cytology , Lung/metabolism , Male , Mice , Mice, Inbred BALB C , Nasal Lavage/methods , Nasal Lavage Fluid/cytology , Nasal Mucosa/cytology , Nasal Mucosa/immunology , Nasal Mucosa/metabolism , Neutrophils/metabolism , Time Factors , Young Adult
15.
Protein Expr Purif ; 190: 106003, 2022 02.
Article in English | MEDLINE | ID: covidwho-1474960

ABSTRACT

SARS-CoV-2 protein subunit vaccines are currently being evaluated by multiple manufacturers to address the global vaccine equity gap, and need for low-cost, easy to scale, safe, and effective COVID-19 vaccines. In this paper, we report on the generation of the receptor-binding domain RBD203-N1 yeast expression construct, which produces a recombinant protein capable of eliciting a robust immune response and protection in mice against SARS-CoV-2 challenge infections. The RBD203-N1 antigen was expressed in the yeast Pichia pastoris X33. After fermentation at the 5 L scale, the protein was purified by hydrophobic interaction chromatography followed by anion exchange chromatography. The purified protein was characterized biophysically and biochemically, and after its formulation, the immunogenicity was evaluated in mice. Sera were evaluated for their efficacy using a SARS-CoV-2 pseudovirus assay. The RBD203-N1 protein was expressed with a yield of 492.9 ± 3.0 mg/L of fermentation supernatant. A two-step purification process produced a >96% pure protein with a recovery rate of 55 ± 3% (total yield of purified protein: 270.5 ± 13.2 mg/L fermentation supernatant). The protein was characterized to be a homogeneous monomer that showed a well-defined secondary structure, was thermally stable, antigenic, and when adjuvanted on Alhydrogel in the presence of CpG it was immunogenic and induced high levels of neutralizing antibodies against SARS-CoV-2 pseudovirus. The characteristics of the RBD203-N1 protein-based vaccine show that this candidate is another well suited RBD-based construct for technology transfer to manufacturing entities and feasibility of transition into the clinic to evaluate its immunogenicity and safety in humans.


Subject(s)
COVID-19 Vaccines , Gene Expression , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Animals , COVID-19 Vaccines/chemistry , COVID-19 Vaccines/genetics , COVID-19 Vaccines/pharmacology , Humans , Mice , Protein Domains , Recombinant Proteins/biosynthesis , Recombinant Proteins/chemistry , Recombinant Proteins/pharmacology , SARS-CoV-2/chemistry , SARS-CoV-2/genetics , Saccharomyces cerevisiae/chemistry , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/pharmacology
16.
J Mol Model ; 27(11): 323, 2021 Oct 13.
Article in English | MEDLINE | ID: covidwho-1465873

ABSTRACT

The world has face the COVID-19 pandemic which has already caused millions of death. Due to the urgency in fighting the virus, we study five residues of free amino acids present in the structure of the SARS-CoV-2 spike protein (S). We investigated the spontaneous interaction between amino acids and silver ions (Ag+), considering these ions as a virucide chemical agent for SARS-CoV-2. The amino acid-Ag+ systems were investigated in a gaseous medium and a simulated water environment was described with a continuum model (PCM) the calculations were performed within the framework of density functional theory (DFT). Calculations related to the occupied orbitals of higher energy showed that Ag+ has a tendency to interact with the nitrile groups (-NH). The negative values of the Gibbs free energies show that the interaction process between amino acids-Ag+ in both media occurs spontaneously. There is a decrease in Gibbs free energy from the amino acid-Ag+ interactions immersed in a water solvation simulator.


Subject(s)
Amino Acids/chemistry , Antiviral Agents/chemistry , Density Functional Theory , Silver/chemistry , Spike Glycoprotein, Coronavirus/chemistry , Amino Acids/metabolism , Antiviral Agents/metabolism , Binding Sites , Cations, Monovalent , Gene Expression , Humans , Protein Binding , Protein Conformation, alpha-Helical , Protein Conformation, beta-Strand , Protein Interaction Domains and Motifs , SARS-CoV-2/chemistry , Silver/metabolism , Spike Glycoprotein, Coronavirus/antagonists & inhibitors , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism , Static Electricity , Thermodynamics
17.
Int J Mol Sci ; 22(19)2021 Oct 01.
Article in English | MEDLINE | ID: covidwho-1463708

ABSTRACT

Social behavioral changes, including social isolation or loneliness, increase the risk for stress-related disorders, such as major depressive disorder, posttraumatic stress disorder (PTSD), and suicide, which share a strong neuroinflammatory etiopathogenetic component. The peroxisome-proliferator activated receptor (PPAR)-α, a newly discovered target involved in emotional behavior regulation, is a ligand-activated nuclear receptor and a transcription factor that, following stimulation by endogenous or synthetic ligands, may induce neuroprotective effects by modulating neuroinflammation, and improve anxiety and depression-like behaviors by enhancing neurosteroid biosynthesis. How stress affects epigenetic mechanisms with downstream effects on inflammation and emotional behavior remains poorly understood. We studied the effects of 4-week social isolation, using a mouse model of PTSD/suicide-like behavior, on hippocampal PPAR-α epigenetic modification. Decreased PPAR-α expression in the hippocampus of socially isolated mice was associated with increased levels of methylated cytosines of PPAR-α gene CpG-rich fragments and deficient neurosteroid biosynthesis. This effect was associated with increased histone deacetylases (HDAC)1, methyl-cytosine binding protein (MeCP)2 and decreased ten-eleven translocator (TET)2 expression, which favor hypermethylation. These alterations were associated with increased TLR-4 and pro-inflammatory markers (e.g., TNF-α,), mediated by NF-κB signaling in the hippocampus of aggressive mice. This study contributes the first evidence of stress-induced brain PPAR-α epigenetic regulation. Social isolation stress may constitute a risk factor for inflammatory-based psychiatric disorders associated with neurosteroid deficits, and targeting epigenetic marks linked to PPAR-α downregulation may offer a valid therapeutic approach.


Subject(s)
Aggression , Hippocampus/metabolism , Inflammation/etiology , PPAR alpha/genetics , Social Isolation , Stress, Psychological , Aggression/psychology , Animals , Behavior, Animal , Chromatin Assembly and Disassembly , CpG Islands , Disease Models, Animal , Disease Susceptibility , Epigenesis, Genetic , Gene Expression , Inflammation/metabolism , Inflammation Mediators/metabolism , Male , Methylation , Mice , PPAR alpha/metabolism , Promoter Regions, Genetic , Signal Transduction
18.
Virus Res ; 305: 198563, 2021 11.
Article in English | MEDLINE | ID: covidwho-1415831

ABSTRACT

This study compared the lethality of severe acute respiratory syndrome coronavirus 2 variants belonging to the S, V, L, G, GH, and GR clades using K18-human angiotensin-converting enzyme 2 heterozygous mice. To estimate the 50% lethal dose (LD50) of each variant, increasing viral loads (100-104 plaque-forming units [PFU]) were administered intranasally. Mouse weight and survival were monitored for 14 days. The LD50 of the GH and GR clades was significantly lower than that of other clades at 50 PFU. These findings suggest that the GH and GR clades, which are prevalent worldwide, are more virulent than the other clades.


Subject(s)
Angiotensin-Converting Enzyme 2/genetics , COVID-19/mortality , Receptors, Virus/genetics , SARS-CoV-2/genetics , SARS-CoV-2/pathogenicity , Viral Load/genetics , Amino Acid Sequence , Angiotensin-Converting Enzyme 2/metabolism , Animals , Base Sequence , Body Weight , COVID-19/pathology , COVID-19/virology , Chlorocebus aethiops , Gene Expression , Humans , Lethal Dose 50 , Male , Mice , Mice, Transgenic , Phylogeny , Receptors, Virus/metabolism , SARS-CoV-2/classification , SARS-CoV-2/metabolism , Severity of Illness Index , Survival Analysis , Transgenes , Vero Cells , Viral Plaque Assay , Virulence
19.
Int J Biol Macromol ; 190: 409-416, 2021 Nov 01.
Article in English | MEDLINE | ID: covidwho-1412931

ABSTRACT

Coronavirus Disease 2019 (COVID-19) caused by a novel betacoronavirus SARS-CoV-2 has been an ongoing global pandemic. Several vaccines have been developed to control the COVID-19, but the potential effectiveness of the mucosal vaccine remains to be documented. In this study, we constructed a recombinant L. plantarum LP18:RBD expressing the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein via the surface anchoring route. The amount of the RBD protein was maximally expressed under the culture condition with 200 ng/mL of inducer at 33 °C for 6 h. Further, we evaluated the immune response in mice via the intranasal administration of LP18:RBD. The results showed that the LP18:RBD significantly elicited RBD-specific mucosal IgA antibodies in respiratory tract and intestinal tract. The percentages of CD3 + CD4+ T cells in spleens of mice administrated with the LP18:RBD were also significantly increased. This indicated that LP18:RBD could induce a humoral immune response at the mucosa, and it could be used as a mucosal vaccine candidate against the SARS-CoV-2 infection. We provided the first experimental evidence that the recombinant L. plantarum LP18:RBD could initiate immune response in vivo, which implies that the mucosal immunization using recombinant LAB system could be a promising vaccination strategy to prevent the COVID-19 pandemic.


Subject(s)
Antibodies, Viral/immunology , COVID-19/immunology , Immunity, Mucosal , Immunoglobulin A/immunology , Lactobacillus plantarum , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Administration, Intranasal , Animals , COVID-19/genetics , COVID-19/prevention & control , Gene Expression , Lactobacillus plantarum/genetics , Lactobacillus plantarum/immunology , Mice , Mice, Inbred BALB C , Protein Domains , Recombinant Proteins/genetics , Recombinant Proteins/immunology , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics
20.
JCI Insight ; 6(20)2021 10 22.
Article in English | MEDLINE | ID: covidwho-1403154

ABSTRACT

Endothelial dysfunction accompanies the microvascular thrombosis commonly observed in severe COVID-19. Constitutively, the endothelial surface is anticoagulant, a property maintained at least in part via signaling through the Tie2 receptor. During inflammation, the Tie2 antagonist angiopoietin-2 (Angpt-2) is released from endothelial cells and inhibits Tie2, promoting a prothrombotic phenotypic shift. We sought to assess whether severe COVID-19 is associated with procoagulant endothelial dysfunction and alterations in the Tie2/angiopoietin axis. Primary HUVECs treated with plasma from patients with severe COVID-19 upregulated the expression of thromboinflammatory genes, inhibited the expression of antithrombotic genes, and promoted coagulation on the endothelial surface. Pharmacologic activation of Tie2 with the small molecule AKB-9778 reversed the prothrombotic state induced by COVID-19 plasma in primary endothelial cells. Lung autopsies from patients with COVID-19 demonstrated a prothrombotic endothelial signature. Assessment of circulating endothelial markers in a cohort of 98 patients with mild, moderate, or severe COVID-19 revealed endothelial dysfunction indicative of a prothrombotic state. Angpt-2 concentrations rose with increasing disease severity, and the highest levels were associated with worse survival. These data highlight the disruption of Tie2/angiopoietin signaling and procoagulant changes in endothelial cells in severe COVID-19. Our findings provide rationale for current trials of Tie2-activating therapy with AKB-9778 in COVID-19.


Subject(s)
COVID-19/drug therapy , Endothelial Cells/drug effects , Protective Agents/pharmacology , Receptor, TIE-2/metabolism , Adult , Aged , Aged, 80 and over , Angiopoietin-2/metabolism , Aniline Compounds , Female , Gene Expression , Humans , Lung , Male , Middle Aged , Receptor, TIE-2/genetics , SARS-CoV-2 , Signal Transduction , Sulfonic Acids , Vascular Diseases/metabolism , Young Adult
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