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1.
Sci Rep ; 11(1): 24448, 2021 12 27.
Article in English | MEDLINE | ID: covidwho-1852474

ABSTRACT

COVID-19 mRNA vaccines are highly effective at preventing COVID-19. Prior studies have found detectable SARS-CoV-2 IgG antibodies in oral mucosal specimens of participants with history of COVID-19. To assess the development of oral SARS-CoV-2 IgG antibodies among people who received either the Moderna or Pfizer/BioNTech COVID-19 vaccination series, we developed a novel SARS-CoV-2 IgG enzyme-linked immunosorbent assay (ELISA) to quantify the concentrations of oral and nasal mucosal SARS-CoV-2 IgG levels. We enrolled 52 participants who received the Moderna vaccine and 80 participants who received the Pfizer/BioNTech vaccine. Oral mucosal specimens were self-collected by participants prior to or on the day of vaccination, and on days 5, 10, 15, and 20 following each vaccination dose and 30, 60, and 90 days following the second vaccination dose. A subset of the cohort provided additional nasal mucosal specimens at every time point. All participants developed detectable oral mucosal SARS-CoV-2 IgG antibodies by 15 days after the first vaccination dose. There were no significant differences in oral mucosal antibody concentrations once participants were fully vaccinated in the Moderna and Pfizer/BioNTech vaccines. Oral or nasal mucosal antibody testing could be an inexpensive and less invasive alternative to serum antibody testing. Further research is needed to understand the duration of detectable oral or nasal mucosal antibodies and how antibody concentrations change with time.


Subject(s)
Antibodies, Viral/analysis , Immunoglobulin G/analysis , Mouth Mucosa/metabolism , Respiratory System/metabolism , /immunology , Adult , Aged , COVID-19/prevention & control , COVID-19/virology , Female , Health Personnel , Humans , Male , Middle Aged , SARS-CoV-2/immunology , SARS-CoV-2/isolation & purification , Time Factors , Vaccination , Young Adult , /administration & dosage
2.
PLoS One ; 17(4): e0265670, 2022.
Article in English | MEDLINE | ID: covidwho-1775445

ABSTRACT

Host biomarkers are increasingly being considered as tools for improved COVID-19 detection and prognosis. We recently profiled circulating host-encoded microRNA (miRNAs) during SARS-CoV-2 infection, revealing a signature that classified COVID-19 cases with 99.9% accuracy. Here we sought to develop a signature suited for clinical application by analyzing specimens collected using minimally invasive procedures. Eight miRNAs displayed altered expression in anterior nasal tissues from COVID-19 patients, with miR-142-3p, a negative regulator of interleukin-6 (IL-6) production, the most strongly upregulated. Supervised machine learning analysis revealed that a three-miRNA signature (miR-30c-2-3p, miR-628-3p and miR-93-5p) independently classifies COVID-19 cases with 100% accuracy. This study further defines the host miRNA response to SARS-CoV-2 infection and identifies candidate biomarkers for improved COVID-19 detection.


Subject(s)
COVID-19 , MicroRNAs , Biomarkers , COVID-19/diagnosis , Gene Expression Profiling , Humans , MicroRNAs/genetics , MicroRNAs/metabolism , Respiratory System/metabolism , SARS-CoV-2/genetics
3.
J Immunol ; 208(4): 979-990, 2022 02 15.
Article in English | MEDLINE | ID: covidwho-1631932

ABSTRACT

Calprotectin is released by activated neutrophils along with myeloperoxidase (MPO) and proteases. It plays numerous roles in inflammation and infection, and is used as an inflammatory biomarker. However, calprotectin is readily oxidized by MPO-derived hypohalous acids to form covalent dimers of its S100A8 and S100A9 subunits. The dimers are susceptible to degradation by proteases. We show that detection of human calprotectin by ELISA declines markedly because of its oxidation by hypochlorous acid and subsequent degradation. Also, proteolysis liberates specific peptides from oxidized calprotectin that is present at inflammatory sites. We identified six calprotectin-derived peptides by mass spectrometry and detected them in the bronchoalveolar lavage fluid of children with cystic fibrosis (CF). We assessed the peptides as biomarkers of neutrophilic inflammation and infection. The content of the calprotectin peptide ILVI was related to calprotectin (r = 0.72, p = 0.01, n = 10). Four of the peptides were correlated with the concentration of MPO (r > 0.7, p ≤ 0.01, n = 21), while three were higher (p < 0.05) in neutrophil elastase-positive (n = 14) than -negative samples (n = 7). Also, five of the peptides were higher (p < 0.05) in the bronchoalveolar lavage fluid from children with CF with infections (n = 21) than from non-CF children without infections (n = 6). The specific peptides liberated from calprotectin will signal uncontrolled activity of proteases and MPO during inflammation. They may prove useful in tracking inflammation in respiratory diseases dominated by neutrophils, including coronavirus disease 2019.


Subject(s)
Bronchoalveolar Lavage Fluid/immunology , Cystic Fibrosis/immunology , Inflammation/immunology , Leukocyte L1 Antigen Complex/metabolism , Neutrophils/immunology , Peptides/metabolism , Respiratory System/metabolism , Child , Child, Preschool , Cystic Fibrosis/diagnosis , Female , Humans , Inflammation/diagnosis , Leukocyte L1 Antigen Complex/genetics , Leukocyte L1 Antigen Complex/immunology , Male , Neutrophil Activation , Oxidation-Reduction , Peptides/genetics , Peptides/immunology , Proteolysis
4.
Respiration ; 101(6): 610-618, 2022.
Article in English | MEDLINE | ID: covidwho-1626135

ABSTRACT

BACKGROUND: The novel beta-coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), enters the human body via mucosal surfaces of the upper and/or lower respiratory tract. Viral entry into epithelial cells is mediated via angiotensin-converting enzyme 2 (ACE2) and auxiliary molecules, but the precise anatomic site of infection still remains unclear. METHODS: Here, we systematically investigated the main SARS-CoV-2 receptor proteins ACE2 and transmembrane serine protease 2 (TMPRSS2), as well as 2 molecules potentially involved in viral entry, furin and CD147, in formalin-fixed, paraffin-embedded human tissues. Tissue microarrays incorporating a total of 879 tissue cores from conjunctival (n = 84), sinonasal (n = 95), and lung (bronchiolar/alveolar; n = 96) specimens were investigated for protein expression by immunohistochemistry. RESULTS: ACE2 and TMPRSS2 were expressed in ciliated epithelial cells of the conjunctivae and sinonasal tissues, with highest expression levels observed in the apical cilia. In contrast, in the lung, the expression of those molecules in bronchiolar and alveolar epithelial cells was much rarer and only very focal when present. Furin and CD147 were more uniformly expressed in all tissues analyzed, including the lung. Interestingly, alveolar macrophages consistently expressed high levels of all 4 molecules investigated. CONCLUSIONS: Our study confirms and extends previous findings and contributes to a better understanding of potential SARS-CoV-2 infection sites along the human respiratory tract.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , Basigin/metabolism , Furin/metabolism , Respiratory System/metabolism , SARS-CoV-2 , Serine Endopeptidases/metabolism , Virus Internalization , COVID-19/metabolism , COVID-19/virology , Humans , Lung/metabolism , Respiratory System/virology
5.
Int J Mol Sci ; 23(3)2022 Jan 19.
Article in English | MEDLINE | ID: covidwho-1625612

ABSTRACT

Repurposing of the anthelminthic drug niclosamide was proposed as an effective treatment for inflammatory airway diseases such as asthma, cystic fibrosis, and chronic obstructive pulmonary disease. Niclosamide may also be effective for the treatment of viral respiratory infections, such as SARS-CoV-2, respiratory syncytial virus, and influenza. While systemic application of niclosamide may lead to unwanted side effects, local administration via aerosol may circumvent these problems, particularly when the drug is encapsulated into small polyethylene glycol (PEG) hydrospheres. In the present study, we examined whether PEG-encapsulated niclosamide inhibits the production of mucus and affects the pro-inflammatory mediator CLCA1 in mouse airways in vivo, while effects on mucociliary clearance were assessed in excised mouse tracheas. The potential of encapsulated niclosamide to inhibit TMEM16A whole-cell Cl- currents and intracellular Ca2+ signalling was assessed in airway epithelial cells in vitro. We achieved encapsulation of niclosamide in PEG-microspheres and PEG-nanospheres (Niclo-spheres). When applied to asthmatic mice via intratracheal instillation, Niclo-spheres strongly attenuated overproduction of mucus, inhibited secretion of the major proinflammatory mediator CLCA1, and improved mucociliary clearance in tracheas ex vivo. These effects were comparable for niclosamide encapsulated in PEG-nanospheres and PEG-microspheres. Niclo-spheres inhibited the Ca2+ activated Cl- channel TMEM16A and attenuated mucus production in CFBE and Calu-3 human airway epithelial cells. Both inhibitory effects were explained by a pronounced inhibition of intracellular Ca2+ signals. The data indicate that poorly dissolvable compounds such as niclosamide can be encapsulated in PEG-microspheres/nanospheres and deposited locally on the airway epithelium as encapsulated drugs, which may be advantageous over systemic application.


Subject(s)
Niclosamide/administration & dosage , Pneumonia/drug therapy , Respiratory System/drug effects , Animals , Asthma/drug therapy , Asthma/metabolism , Asthma/pathology , COVID-19/complications , COVID-19/drug therapy , Cells, Cultured , Disease Models, Animal , Drug Carriers/chemistry , Drug Compounding , Humans , Hydrogels/chemistry , Instillation, Drug , Mice , Microspheres , Mucus/drug effects , Mucus/metabolism , Nanospheres/administration & dosage , Nanospheres/chemistry , Niclosamide/chemistry , Niclosamide/pharmacokinetics , Pneumonia/pathology , Polyethylene Glycols/chemistry , Respiratory Mucosa/drug effects , Respiratory Mucosa/metabolism , Respiratory System/metabolism , SARS-CoV-2/drug effects , SARS-CoV-2/physiology , Trachea
6.
Am J Pathol ; 191(12): 2064-2071, 2021 12.
Article in English | MEDLINE | ID: covidwho-1506649

ABSTRACT

Current understanding of coronavirus disease 2019 (COVID-19) pathophysiology is limited by disease heterogeneity, complexity, and a paucity of studies assessing patient tissues with advanced molecular tools. Rapid autopsy tissues were evaluated using multiscale, next-generation RNA-sequencing methods (bulk, single-nuclei, and spatial transcriptomics) to provide unprecedented molecular resolution of COVID-19-induced damage. Comparison of infected/uninfected tissues revealed four major regulatory pathways. Effectors within these pathways could constitute novel therapeutic targets, including the complement receptor C3AR1, calcitonin receptor-like receptor, or decorin. Single-nuclei RNA sequencing of olfactory bulb and prefrontal cortex highlighted remarkable diversity of coronavirus receptors. Angiotensin-converting enzyme 2 was rarely expressed, whereas basigin showed diffuse expression, and alanyl aminopeptidase, membrane, was associated with vascular/mesenchymal cell types. Comparison of lung and lymph node tissues from patients with different symptoms (one had died after a month-long hospitalization with multiorgan involvement, and the other had died after a few days of respiratory symptoms) with digital spatial profiling resulted in distinct molecular phenotypes. Evaluation of COVID-19 rapid autopsy tissues with advanced molecular techniques can identify pathways and effectors, map diverse receptors at the single-cell level, and help dissect differences driving diverging clinical courses among individual patients. Extension of this approach to larger data sets will substantially advance the understanding of the mechanisms behind COVID-19 pathophysiology.


Subject(s)
COVID-19/genetics , COVID-19/pathology , SARS-CoV-2/pathogenicity , Autopsy , Disease Progression , Gene Expression Profiling , Heart/virology , Host-Pathogen Interactions/genetics , Humans , Kidney/metabolism , Kidney/pathology , Kidney/virology , Liver/metabolism , Liver/pathology , Liver/virology , Male , Middle Aged , Myocardium/metabolism , Myocardium/pathology , Olfactory Bulb/metabolism , Olfactory Bulb/pathology , Olfactory Bulb/virology , Prefrontal Cortex/metabolism , Prefrontal Cortex/pathology , Prefrontal Cortex/virology , Respiratory System/metabolism , Respiratory System/pathology , Respiratory System/virology , Salivary Glands/metabolism , Salivary Glands/pathology , Salivary Glands/virology , Sequence Analysis, RNA , Signal Transduction/genetics
7.
PLoS One ; 16(10): e0257644, 2021.
Article in English | MEDLINE | ID: covidwho-1496499

ABSTRACT

BACKGROUND: COVID-19 may present with a variety of clinical syndromes, however, the upper airway and the lower respiratory tract are the principle sites of infection. Previous work on respiratory viral infections demonstrated that airway inflammation results in the release of volatile organic compounds as well as nitric oxide. The detection of these gases from patients' exhaled breath offers a novel potential diagnostic target for COVID-19 that would offer real-time screening of patients for COVID-19 infection. METHODS AND FINDINGS: We present here a breath tester utilizing a catalytically active material, which allows for the temporal manifestation of the gaseous biomarkers' interactions with the sensor, thus giving a distinct breath print of the disease. A total of 46 Intensive Care Unit (ICU) patients on mechanical ventilation participated in the study, 23 with active COVID-19 respiratory infection and 23 non-COVID-19 controls. Exhaled breath bags were collected on ICU days 1, 3, 7, and 10 or until liberation from mechanical ventilation. The breathalyzer detected high exhaled nitric oxide (NO) concentration with a distinctive pattern for patients with active COVID-19 pneumonia. The COVID-19 "breath print" has the pattern of the small Greek letter omega (). The "breath print" identified patients with COVID-19 pneumonia with 88% accuracy upon their admission to the ICU. Furthermore, the sensitivity index of the breath print (which scales with the concentration of the key biomarker ammonia) appears to correlate with duration of COVID-19 infection. CONCLUSIONS: The implication of this breath tester technology for the rapid screening for COVID-19 and potentially detection of other infectious diseases in the future.


Subject(s)
COVID-19/diagnosis , COVID-19/metabolism , Nitric Oxide/analysis , Aged , Biomarkers , Breath Tests/methods , Critical Illness , Female , Humans , Male , Middle Aged , Nitric Oxide/metabolism , Respiratory System/metabolism , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity , Sensitivity and Specificity , Volatile Organic Compounds/analysis
8.
Sci Rep ; 11(1): 20615, 2021 10 18.
Article in English | MEDLINE | ID: covidwho-1475482

ABSTRACT

Differential kinetics of RNA loads and infectious viral levels in the upper respiratory tract between asymptomatic and symptomatic SARS-CoV-2 infected adult outpatients remain unclear limiting recommendations that may guide clinical management, infection control measures and occupational health decisions. In the present investigation, 496 (2.8%) of 17,911 French adult outpatients were positive for an upper respiratory tract SARS-CoV-2 RNA detection by a quantitative RT-PCR assay, of which 180 (36.3%) were COVID-19 asymptomatic. Of these adult asymptomatic viral shedders, 75% had mean to high RNA viral loads (Ct values < 30) which median value was significantly higher than that observed in symptomatic subjects (P = 0.029), and 50.6% were positive by cell culture assays of their upper respiratory tract specimens. Our findings indicate that COVID-19 asymptomatic adult outpatients are significant viable SARS-CoV-2 shedders in their upper respiratory tract playing a major potential role as SARS-CoV-2 transmitters in various epidemiological transmission chains, promoting COVID-19 resurgence in populations.


Subject(s)
COVID-19/therapy , COVID-19/virology , Outpatients , SARS-CoV-2 , Virus Shedding , Adolescent , Adult , Animals , Asymptomatic Infections , COVID-19 Nucleic Acid Testing , Chlorocebus aethiops , Female , France , Humans , Kinetics , Male , Middle Aged , RNA, Viral , Respiratory System/metabolism , Vero Cells , Viral Load , Young Adult
9.
Front Immunol ; 12: 701443, 2021.
Article in English | MEDLINE | ID: covidwho-1470757

ABSTRACT

The airway mucus barrier is a primary defensive layer at the airway surface. Mucins are the major structural components of airway mucus that protect the respiratory tract. Respiratory viruses invade human airways and often induce abnormal mucin overproduction and airway mucus secretion, leading to airway obstruction and disease. The mechanism underlying the virus-induced abnormal airway mucus secretion has not been fully studied so far. Understanding the mechanisms by which viruses induce airway mucus hypersecretion may open new avenues to treatment. In this article, we elaborate the clinical and experimental evidence that respiratory viruses cause abnormal airway mucus secretion, review the underlying mechanisms, and also discuss the current research advance as well as potential strategies to treat the abnormal airway mucus secretion caused by SARS-CoV-2.


Subject(s)
Mucus/metabolism , Virus Diseases/metabolism , Animals , Humans , Respiratory System/metabolism
10.
Viruses ; 12(10)2020 10 16.
Article in English | MEDLINE | ID: covidwho-1389518

ABSTRACT

To address the expression pattern of the SARS-CoV-2 receptor ACE2 and the viral priming protease TMPRSS2 in the respiratory tract, this study investigated RNA sequencing transcriptome profiling of samples of airway and oral mucosa. As shown, ACE2 has medium levels of expression in both small airway epithelium and masticatory mucosa, and high levels of expression in nasal epithelium. The expression of ACE2 is low in mucosal-associated invariant T (MAIT) cells and cannot be detected in alveolar macrophages. TMPRSS2 is highly expressed in small airway epithelium and nasal epithelium and has lower expression in masticatory mucosa. Our results provide the molecular basis that the nasal mucosa is the most susceptible locus in the respiratory tract for SARS-CoV-2 infection and consequently for subsequent droplet transmission and should be the focus for protection against SARS-CoV-2 infection.


Subject(s)
Betacoronavirus/physiology , Coronavirus Infections/genetics , Peptidyl-Dipeptidase A/biosynthesis , Pneumonia, Viral/genetics , Serine Endopeptidases/biosynthesis , Virus Internalization , Angiotensin-Converting Enzyme 2 , COVID-19 , Coronavirus Infections/metabolism , Coronavirus Infections/virology , Epithelium/metabolism , Epithelium/virology , Gene Expression , Gene Expression Profiling , Humans , Nasal Mucosa/metabolism , Nasal Mucosa/virology , Pandemics , Peptidyl-Dipeptidase A/genetics , Pneumonia, Viral/metabolism , Pneumonia, Viral/virology , Respiratory System/metabolism , Respiratory System/virology , SARS-CoV-2 , Serine Endopeptidases/genetics
11.
Nat Med ; 27(3): 546-559, 2021 03.
Article in English | MEDLINE | ID: covidwho-1319033

ABSTRACT

Angiotensin-converting enzyme 2 (ACE2) and accessory proteases (TMPRSS2 and CTSL) are needed for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cellular entry, and their expression may shed light on viral tropism and impact across the body. We assessed the cell-type-specific expression of ACE2, TMPRSS2 and CTSL across 107 single-cell RNA-sequencing studies from different tissues. ACE2, TMPRSS2 and CTSL are coexpressed in specific subsets of respiratory epithelial cells in the nasal passages, airways and alveoli, and in cells from other organs associated with coronavirus disease 2019 (COVID-19) transmission or pathology. We performed a meta-analysis of 31 lung single-cell RNA-sequencing studies with 1,320,896 cells from 377 nasal, airway and lung parenchyma samples from 228 individuals. This revealed cell-type-specific associations of age, sex and smoking with expression levels of ACE2, TMPRSS2 and CTSL. Expression of entry factors increased with age and in males, including in airway secretory cells and alveolar type 2 cells. Expression programs shared by ACE2+TMPRSS2+ cells in nasal, lung and gut tissues included genes that may mediate viral entry, key immune functions and epithelial-macrophage cross-talk, such as genes involved in the interleukin-6, interleukin-1, tumor necrosis factor and complement pathways. Cell-type-specific expression patterns may contribute to the pathogenesis of COVID-19, and our work highlights putative molecular pathways for therapeutic intervention.


Subject(s)
COVID-19/epidemiology , COVID-19/genetics , Host-Pathogen Interactions/genetics , SARS-CoV-2/physiology , Sequence Analysis, RNA/statistics & numerical data , Single-Cell Analysis/statistics & numerical data , Virus Internalization , Adult , Aged , Aged, 80 and over , Alveolar Epithelial Cells/metabolism , Alveolar Epithelial Cells/virology , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , COVID-19/pathology , COVID-19/virology , Cathepsin L/genetics , Cathepsin L/metabolism , Datasets as Topic/statistics & numerical data , Demography , Female , Gene Expression Profiling/statistics & numerical data , Humans , Lung/metabolism , Lung/virology , Male , Middle Aged , Organ Specificity/genetics , Respiratory System/metabolism , Respiratory System/virology , Sequence Analysis, RNA/methods , Serine Endopeptidases/genetics , Serine Endopeptidases/metabolism , Single-Cell Analysis/methods
12.
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
13.
PLoS Pathog ; 17(4): e1009500, 2021 04.
Article in English | MEDLINE | ID: covidwho-1197396

ABSTRACT

The high transmissibility of SARS-CoV-2 is related to abundant replication in the upper airways, which is not observed for the other highly pathogenic coronaviruses SARS-CoV and MERS-CoV. We here reveal features of the coronavirus spike (S) protein, which optimize the virus towards the human respiratory tract. First, the S proteins exhibit an intrinsic temperature preference, corresponding with the temperature of the upper or lower airways. Pseudoviruses bearing the SARS-CoV-2 spike (SARS-2-S) were more infectious when produced at 33°C instead of 37°C, a property shared with the S protein of HCoV-229E, a common cold coronavirus. In contrast, the S proteins of SARS-CoV and MERS-CoV favored 37°C, in accordance with virus preference for the lower airways. Next, SARS-2-S-driven entry was efficiently activated by not only TMPRSS2, but also the TMPRSS13 protease, thus broadening the cell tropism of SARS-CoV-2. Both proteases proved relevant in the context of authentic virus replication. TMPRSS13 appeared an effective spike activator for the virulent coronaviruses but not the low pathogenic HCoV-229E virus. Activation of SARS-2-S by these surface proteases requires processing of the S1/S2 cleavage loop, in which both the furin recognition motif and extended loop length proved critical. Conversely, entry of loop deletion mutants is significantly increased in cathepsin-rich cells. Finally, we demonstrate that the D614G mutation increases SARS-CoV-2 stability, particularly at 37°C, and, enhances its use of the cathepsin L pathway. This indicates a link between S protein stability and usage of this alternative route for virus entry. Since these spike properties may promote virus spread, they potentially explain why the spike-G614 variant has replaced the early D614 variant to become globally predominant. Collectively, our findings reveal adaptive mechanisms whereby the coronavirus spike protein is adjusted to match the temperature and protease conditions of the airways, to enhance virus transmission and pathology.


Subject(s)
COVID-19/metabolism , Respiratory System/metabolism , Respiratory System/virology , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/metabolism , COVID-19/transmission , Coronavirus 229E, Human/metabolism , Furin/metabolism , Humans , Membrane Proteins/metabolism , Middle East Respiratory Syndrome Coronavirus/metabolism , Peptide Hydrolases/metabolism , Serine Endopeptidases/metabolism , Spike Glycoprotein, Coronavirus/genetics , Temperature , Virus Internalization , Virus Replication/physiology
14.
Anat Rec (Hoboken) ; 304(6): 1185-1193, 2021 06.
Article in English | MEDLINE | ID: covidwho-1184569

ABSTRACT

Estrogen is an important hormone for health in both genders. It is indispensable to glucose homeostasis, immune robustness, bone health, cardiovascular health, and neural functions. The main way that estrogen acts in the cells is through estrogen receptors (ERs). The presence of specific estrogen receptors is required for estrogen to have its characteristic ubiquitous action in almost all tissues. Estrogen receptor alpha (ERα) and estrogen receptor beta (ERß) are the major isoforms of estrogen that are highly specific in humans and enable selective hormonal actions in different tissues. This article reviews some of the observed estrogen actions and effects in different tissues and cells through these specific receptors. This ubiquitous, almost ordinary hormone may reveal itself as a significant factor that helped us to better understand the complexity of the human immune system response against respiratory infections, including the COVID-19, and especially in the current state of this painful pandemic.


Subject(s)
COVID-19/immunology , Estrogen Receptor alpha/immunology , Estrogen Receptor beta/immunology , Immune System/immunology , Respiratory System/immunology , SARS-CoV-2/immunology , Animals , COVID-19/metabolism , Estrogen Receptor alpha/metabolism , Estrogen Receptor beta/metabolism , Humans , Immune System/metabolism , Nasal Mucosa/immunology , Nasal Mucosa/metabolism , Respiratory System/metabolism , SARS-CoV-2/metabolism
15.
Nitric Oxide ; 111-112: 64-71, 2021 06 01.
Article in English | MEDLINE | ID: covidwho-1164254

ABSTRACT

Symptoms of COVID-19 range from asymptomatic/mild symptoms to severe illness and death, consequence of an excessive inflammatory process triggered by SARS-CoV-2 infection. The diffuse inflammation leads to endothelium dysfunction in pulmonary blood vessels, uncoupling eNOS activity, lowering NO production, causing pulmonary physiological alterations and coagulopathy. On the other hand, iNOS activity is increased, which may be advantageous for host defense, once NO plays antiviral effects. However, overproduction of NO may be deleterious, generating a pro-inflammatory effect. In this review, we discussed the role of endogenous NO as a protective or deleterious agent of the respiratory and vascular systems, the most affected in COVID-19 patients, focusing on eNOS and iNOS roles. We also reviewed the currently available NO therapies and pointed out possible alternative treatments targeting NO metabolism, which could help mitigate health crises in the present and future CoV's spillovers.


Subject(s)
COVID-19/metabolism , Nitric Oxide Synthase Type III/metabolism , Nitric Oxide Synthase Type II/metabolism , Nitric Oxide/metabolism , SARS-CoV-2 , Blood Vessels/metabolism , Gene Expression Regulation, Enzymologic , Humans , Nitric Oxide Synthase Type II/genetics , Nitric Oxide Synthase Type III/genetics , Respiratory System/metabolism
16.
Nat Med ; 27(3): 546-559, 2021 03.
Article in English | MEDLINE | ID: covidwho-1114717

ABSTRACT

Angiotensin-converting enzyme 2 (ACE2) and accessory proteases (TMPRSS2 and CTSL) are needed for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cellular entry, and their expression may shed light on viral tropism and impact across the body. We assessed the cell-type-specific expression of ACE2, TMPRSS2 and CTSL across 107 single-cell RNA-sequencing studies from different tissues. ACE2, TMPRSS2 and CTSL are coexpressed in specific subsets of respiratory epithelial cells in the nasal passages, airways and alveoli, and in cells from other organs associated with coronavirus disease 2019 (COVID-19) transmission or pathology. We performed a meta-analysis of 31 lung single-cell RNA-sequencing studies with 1,320,896 cells from 377 nasal, airway and lung parenchyma samples from 228 individuals. This revealed cell-type-specific associations of age, sex and smoking with expression levels of ACE2, TMPRSS2 and CTSL. Expression of entry factors increased with age and in males, including in airway secretory cells and alveolar type 2 cells. Expression programs shared by ACE2+TMPRSS2+ cells in nasal, lung and gut tissues included genes that may mediate viral entry, key immune functions and epithelial-macrophage cross-talk, such as genes involved in the interleukin-6, interleukin-1, tumor necrosis factor and complement pathways. Cell-type-specific expression patterns may contribute to the pathogenesis of COVID-19, and our work highlights putative molecular pathways for therapeutic intervention.


Subject(s)
COVID-19/epidemiology , COVID-19/genetics , Host-Pathogen Interactions/genetics , SARS-CoV-2/physiology , Sequence Analysis, RNA/statistics & numerical data , Single-Cell Analysis/statistics & numerical data , Virus Internalization , Adult , Aged , Aged, 80 and over , Alveolar Epithelial Cells/metabolism , Alveolar Epithelial Cells/virology , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , COVID-19/pathology , COVID-19/virology , Cathepsin L/genetics , Cathepsin L/metabolism , Datasets as Topic/statistics & numerical data , Demography , Female , Gene Expression Profiling/statistics & numerical data , Humans , Lung/metabolism , Lung/virology , Male , Middle Aged , Organ Specificity/genetics , Respiratory System/metabolism , Respiratory System/virology , Sequence Analysis, RNA/methods , Serine Endopeptidases/genetics , Serine Endopeptidases/metabolism , Single-Cell Analysis/methods
17.
PLoS One ; 16(1): e0245019, 2021.
Article in English | MEDLINE | ID: covidwho-1079325

ABSTRACT

The knowledge on the deposition and retention of the viral particle of SARS-CoV-2 in the respiratory tract during the very initial intake from the ambient air is of prime importance to understand the infectious process and COVID-19 initial symptoms. We propose to use a modified version of a widely tested lung deposition model developed by the ICRP, in the context of the ICRP Publication 66, that provides deposition patterns of microparticles in different lung compartments. In the model, we mimicked the "environmental decay" of the virus, determined by controlled experiments related to normal speeches, by the radionuclide 11C that presents comparable decay rates. Our results confirm clinical observations on the high virus retentions observed in the extrathoracic region and the lesser fraction on the alveolar section (in the order of 5), which may shed light on physiopathology of clinical events as well on the minimal inoculum required to establish infection.


Subject(s)
COVID-19/virology , SARS-CoV-2/physiology , Aerosols/analysis , COVID-19/metabolism , Carbon Radioisotopes , Humans , Lung/metabolism , Lung/pathology , Lung/virology , Models, Biological , Respiratory System/metabolism , Respiratory System/virology
18.
Proc Natl Acad Sci U S A ; 118(8)2021 02 23.
Article in English | MEDLINE | ID: covidwho-1075324

ABSTRACT

COVID-19 transmits by droplets generated from surfaces of airway mucus during processes of respiration within hosts infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. We studied respiratory droplet generation and exhalation in human and nonhuman primate subjects with and without COVID-19 infection to explore whether SARS-CoV-2 infection, and other changes in physiological state, translate into observable evolution of numbers and sizes of exhaled respiratory droplets in healthy and diseased subjects. In our observational cohort study of the exhaled breath particles of 194 healthy human subjects, and in our experimental infection study of eight nonhuman primates infected, by aerosol, with SARS-CoV-2, we found that exhaled aerosol particles vary between subjects by three orders of magnitude, with exhaled respiratory droplet number increasing with degree of COVID-19 infection and elevated BMI-years. We observed that 18% of human subjects (35) accounted for 80% of the exhaled bioaerosol of the group (194), reflecting a superspreader distribution of bioaerosol analogous to a classical 20:80 superspreader of infection distribution. These findings suggest that quantitative assessment and control of exhaled aerosol may be critical to slowing the airborne spread of COVID-19 in the absence of an effective and widely disseminated vaccine.


Subject(s)
COVID-19/physiopathology , COVID-19/transmission , Exhalation/physiology , Obesity/physiopathology , Aerosols , Age Factors , Animals , Body Mass Index , COVID-19/epidemiology , COVID-19/virology , Cohort Studies , Humans , Mucus/chemistry , Mucus/virology , Obesity/epidemiology , Obesity/virology , Particle Size , Primates , Respiratory System/metabolism , SARS-CoV-2/isolation & purification , Viral Load
19.
PLoS One ; 16(1): e0245019, 2021.
Article in English | MEDLINE | ID: covidwho-1067406

ABSTRACT

The knowledge on the deposition and retention of the viral particle of SARS-CoV-2 in the respiratory tract during the very initial intake from the ambient air is of prime importance to understand the infectious process and COVID-19 initial symptoms. We propose to use a modified version of a widely tested lung deposition model developed by the ICRP, in the context of the ICRP Publication 66, that provides deposition patterns of microparticles in different lung compartments. In the model, we mimicked the "environmental decay" of the virus, determined by controlled experiments related to normal speeches, by the radionuclide 11C that presents comparable decay rates. Our results confirm clinical observations on the high virus retentions observed in the extrathoracic region and the lesser fraction on the alveolar section (in the order of 5), which may shed light on physiopathology of clinical events as well on the minimal inoculum required to establish infection.


Subject(s)
COVID-19/virology , SARS-CoV-2/physiology , Aerosols/analysis , COVID-19/metabolism , Carbon Radioisotopes , Humans , Lung/metabolism , Lung/pathology , Lung/virology , Models, Biological , Respiratory System/metabolism , Respiratory System/virology
20.
Nat Biotechnol ; 39(6): 717-726, 2021 06.
Article in English | MEDLINE | ID: covidwho-1065901

ABSTRACT

Cas13a has been used to target RNA viruses in cell culture, but efficacy has not been demonstrated in animal models. In this study, we used messenger RNA (mRNA)-encoded Cas13a for mitigating influenza virus A and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in mice and hamsters, respectively. We designed CRISPR RNAs (crRNAs) specific for PB1 and highly conserved regions of PB2 of influenza virus, and against the replicase and nucleocapsid genes of SARS-CoV-2, and selected the crRNAs that reduced viral RNA levels most efficiently in cell culture. We delivered polymer-formulated Cas13a mRNA and the validated guides to the respiratory tract using a nebulizer. In mice, Cas13a degraded influenza RNA in lung tissue efficiently when delivered after infection, whereas in hamsters, Cas13a delivery reduced SARS-CoV-2 replication and reduced symptoms. Our findings suggest that Cas13a-mediated targeting of pathogenic viruses can mitigate respiratory infections.


Subject(s)
COVID-19/therapy , Influenza, Human/therapy , RNA, Messenger/pharmacology , SARS-CoV-2/genetics , Animals , COVID-19/genetics , COVID-19/virology , CRISPR-Cas Systems/genetics , Cricetinae , Disease Models, Animal , Humans , Influenza, Human/genetics , Influenza, Human/virology , Mice , Orthomyxoviridae/drug effects , Orthomyxoviridae/genetics , Orthomyxoviridae/pathogenicity , RNA, Messenger/genetics , RNA, Viral/genetics , Respiratory System/drug effects , Respiratory System/metabolism , SARS-CoV-2/pathogenicity
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