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1.
Lipids Health Dis ; 20(1): 126, 2021 Oct 03.
Article in English | MEDLINE | ID: covidwho-2196306

ABSTRACT

The coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2). At present, the COVID-19 has been prevalent worldwide for more than a year and caused more than four million deaths. Liver injury was frequently observed in patients with COVID-19. Recently, a new definition of metabolic dysfunction associated fatty liver disease (MAFLD) was proposed by a panel of international experts, and the relationship between MAFLD and COVID-19 has been actively investigated. Several previous studies indicated that the patients with MAFLD had a higher prevalence of COVID-19 and a tendency to develop severe type of respiratory infection, and others indicated that liver injury would be exacerbated in the patients with MAFLD once infected with COVID-19. The mechanism underlying the relationship between MAFLD and COVID-19 infection has not been thoroughly investigated, and recent studies indicated that multifactorial mechanisms, such as altered host angiotensin converting enzyme 2 (ACE2) receptor expression, direct viral attack, disruption of cholangiocyte function, systemic inflammatory reaction, drug-induced liver injury, hepatic ischemic and hypoxic injury, and MAFLD-related glucose and lipid metabolic disorders, might jointly contribute to both of the adverse hepatic and respiratory outcomes. In this review, we discussed the relationship between MAFLD and COVID-19 based on current available literature, and summarized the recommendations for clinical management of MAFLD patients during the pandemic of COVID-19.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , COVID-19/complications , Chemical and Drug Induced Liver Injury/complications , Hypoxia/complications , Liver/metabolism , Non-alcoholic Fatty Liver Disease/complications , SARS-CoV-2/pathogenicity , Age Factors , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , COVID-19/drug therapy , COVID-19/pathology , COVID-19/virology , Chemical and Drug Induced Liver Injury/drug therapy , Chemical and Drug Induced Liver Injury/pathology , Chemical and Drug Induced Liver Injury/virology , Cytokines/genetics , Cytokines/metabolism , Dipeptides/therapeutic use , Gene Expression Regulation , Glucose/metabolism , Glycyrrhizic Acid/therapeutic use , Humans , Hypoxia/drug therapy , Hypoxia/pathology , Hypoxia/virology , Liver/drug effects , Liver/pathology , Liver/virology , Lung/drug effects , Lung/metabolism , Lung/pathology , Lung/virology , Non-alcoholic Fatty Liver Disease/drug therapy , Non-alcoholic Fatty Liver Disease/pathology , Non-alcoholic Fatty Liver Disease/virology , Receptors, Virus/genetics , Receptors, Virus/metabolism , Severity of Illness Index
2.
Cells ; 11(17)2022 09 04.
Article in English | MEDLINE | ID: covidwho-2009960

ABSTRACT

Coronavirus disease-2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a global pandemic and has severely affected socio-economic conditions and people's life. The lung is the major target organ infected and (seriously) damaged by SARS-CoV-2, so a comprehensive understanding of the virus and the mechanism of infection are the first choices to overcome COVID-19. Recent studies have demonstrated the enormous value of human organoids as platforms for virological research, making them an ideal tool for researching host-pathogen interactions. In this study, the various existing lung organoids and their identification biomarkers and applications are summarized. At the same time, the seven coronaviruses currently capable of infecting humans are outlined. Finally, a detailed summary of existing studies on SARS-CoV-2 using lung organoids is provided and includes pathogenesis, drug development, and precision treatment. This review highlights the value of lung organoids in studying SARS-CoV-2 infection, bringing hope that research will alleviate COVID-19-associated lung infections.


Subject(s)
COVID-19 , Lung , Models, Anatomic , Organoids , Humans , Lung/virology , Organoids/virology , SARS-CoV-2
3.
Emerg Microbes Infect ; 11(1): 2160-2175, 2022 Dec.
Article in English | MEDLINE | ID: covidwho-1997031

ABSTRACT

Pandemic outbreaks of viruses such as influenza virus or SARS-CoV-2 are associated with high morbidity and mortality and thus pose a massive threat to global health and economics. Physiologically relevant models are needed to study the viral life cycle, describe the pathophysiological consequences of viral infection, and explore possible drug targets and treatment options. While simple cell culture-based models do not reflect the tissue environment and systemic responses, animal models are linked with huge direct and indirect costs and ethical questions. Ex vivo platforms based on tissue explants have been introduced as suitable platforms to bridge the gap between cell culture and animal models. We established a murine lung tissue explant platform for two respiratory viruses, influenza A virus (IAV) and SARS-CoV-2. We observed efficient viral replication, associated with the release of inflammatory cytokines and the induction of an antiviral interferon response, comparable to ex vivo infection in human lung explants. Endolysosomal entry could be confirmed as a potential host target for pharmacological intervention, and the potential repurposing potentials of fluoxetine and interferons for host-directed therapy previously seen in vitro could be recapitulated in the ex vivo model.


Subject(s)
COVID-19 , Lung , Orthomyxoviridae Infections , Animals , Antiviral Agents/pharmacology , COVID-19/pathology , Fluoxetine/pharmacology , Humans , Influenza A virus/physiology , Influenza, Human/pathology , Interferons , Lung/virology , Mice , Orthomyxoviridae Infections/pathology , SARS-CoV-2/physiology , Tissue Culture Techniques , Virus Replication
4.
Proc Natl Acad Sci U S A ; 119(33): e2203437119, 2022 08 16.
Article in English | MEDLINE | ID: covidwho-1960624

ABSTRACT

The mortality of coronavirus disease 2019 (COVID-19) is strongly correlated with pulmonary vascular pathology accompanied by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection-triggered immune dysregulation and aberrant activation of platelets. We combined histological analyses using field emission scanning electron microscopy with energy-dispersive X-ray spectroscopy analyses of the lungs from autopsy samples and single-cell RNA sequencing of peripheral blood mononuclear cells to investigate the pathogenesis of vasculitis and immunothrombosis in COVID-19. We found that SARS-CoV-2 accumulated in the pulmonary vessels, causing exudative vasculitis accompanied by the emergence of thrombospondin-1-expressing noncanonical monocytes and the formation of myosin light chain 9 (Myl9)-containing microthrombi in the lung of COVID-19 patients with fatal disease. The amount of plasma Myl9 in COVID-19 was correlated with the clinical severity, and measuring plasma Myl9 together with other markers allowed us to predict the severity of the disease more accurately. This study provides detailed insight into the pathogenesis of vasculitis and immunothrombosis, which may lead to optimal medical treatment for COVID-19.


Subject(s)
COVID-19 , Lung , Myosin Light Chains , SARS-CoV-2 , Severity of Illness Index , Thromboinflammation , Vasculitis , COVID-19/blood , COVID-19/complications , COVID-19/pathology , Humans , Leukocytes, Mononuclear , Lung/blood supply , Lung/metabolism , Lung/pathology , Lung/virology , Myosin Light Chains/blood , RNA-Seq , SARS-CoV-2/isolation & purification , Single-Cell Analysis , Spectrometry, X-Ray Emission , Thromboinflammation/pathology , Thromboinflammation/virology , Vasculitis/pathology , Vasculitis/virology
5.
Front Immunol ; 12: 785349, 2021.
Article in English | MEDLINE | ID: covidwho-1911033

ABSTRACT

SARS-CoV-2 infections present a tremendous threat to public health. Safe and efficacious vaccines are the most effective means in preventing the infections. A variety of vaccines have demonstrated excellent efficacy and safety around the globe. Yet, development of alternative forms of vaccines remains beneficial, particularly those with simpler production processes, less stringent storage conditions, and the capability of being used in heterologous prime/boost regimens which have shown improved efficacy against many diseases. Here we reported a novel DNA vaccine comprised of the SARS-CoV-2 spike protein fused with CD40 ligand (CD40L) serving as both a targeting ligand and molecular adjuvant. A single intramuscular injection in Syrian hamsters induced significant neutralizing antibodies 3-weeks after vaccination, with a boost substantially improving immune responses. Moreover, the vaccine also reduced weight loss and suppressed viral replication in the lungs and nasal turbinates of challenged animals. Finally, the incorporation of CD40L into the DNA vaccine was shown to reduce lung pathology more effectively than the DNA vaccine devoid of CD40L. These results collectively indicate that this DNA vaccine candidate could be further explored because of its efficacy and known safety profile.


Subject(s)
CD40 Ligand/immunology , COVID-19/immunology , Mesocricetus/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Vaccines, DNA/immunology , Adjuvants, Immunologic/pharmacology , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/virology , Cell Line , Female , HEK293 Cells , Humans , Lung/immunology , Lung/virology , Mesocricetus/virology , Models, Animal , Vaccination/methods , Vaccines, Inactivated/immunology
6.
Front Immunol ; 13: 835156, 2022.
Article in English | MEDLINE | ID: covidwho-1902991

ABSTRACT

Complement plays an important role in the direct defense to pathogens, but can also activate immune cells and the release of pro-inflammatory cytokines. However, in critically ill patients with COVID-19 the immune system is inadequately activated leading to severe acute respiratory syndrome (SARS) and acute kidney injury, which is associated with higher mortality. Therefore, we characterized local complement deposition as a sign of activation in both lungs and kidneys from patients with severe COVID-19. Using immunohistochemistry we investigated deposition of complement factors C1q, MASP-2, factor D (CFD), C3c, C3d and C5b-9 as well as myeloperoxidase (MPO) positive neutrophils and SARS-CoV-2 virus particles in lungs and kidneys from 38 patients who died from COVID-19. In addition, tissue damage was analyzed using semi-quantitative scores followed by correlation with complement deposition. Autopsy material from non-COVID patients who died from cardiovascular causes, cerebral hemorrhage and pulmonary embolism served as control (n=8). Lung injury in samples from COVID-19 patients was significantly more pronounced compared to controls with formation of hyaline membranes, thrombi and edema. In addition, in the kidney tubular injury was higher in these patients and correlated with lung injury (r=0.361*). In autopsy samples SARS-CoV-2 spike protein was detected in 22% of the lungs of COVID-19 patients but was lacking in kidneys. Complement activation was significantly stronger in lung samples from patients with COVID-19 via the lectin and alternative pathway as indicated by deposition of MASP-2, CFD, C3d and C5b9. Deposits in the lung were predominantly detected along the alveolar septa, the hyaline membranes and in the alveolar lumina. In the kidney, complement was significantly more deposited in patients with COVID-19 in peritubular capillaries and tubular basement membranes. Renal COVID-19-induced complement activation occurred via the lectin pathway, while activation of the alternative pathway was similar in both groups. Furthermore, MPO-positive neutrophils were found in significantly higher numbers in lungs and kidneys of COVID-19 patients and correlated with local MASP-2 deposition. In conclusion, in patients who died from SARS-CoV-2 infection complement was activated in both lungs and kidneys indicating that complement might be involved in systemic worsening of the inflammatory response. Complement inhibition might thus be a promising treatment option to prevent deregulated activation and subsequent collateral tissue injury in COVID-19.


Subject(s)
COVID-19/immunology , Complement Pathway, Alternative/immunology , Lectins/immunology , Aged , Aged, 80 and over , Autopsy , COVID-19/pathology , COVID-19/virology , Complement System Proteins/immunology , Female , Humans , Kidney/immunology , Kidney/pathology , Kidney/virology , Lung/immunology , Lung/pathology , Lung/virology , Male , Middle Aged , Neutrophils/immunology , Peroxidase/immunology , SARS-CoV-2/immunology
7.
Mol Cell ; 82(13): 2385-2400.e9, 2022 07 07.
Article in English | MEDLINE | ID: covidwho-1851815

ABSTRACT

Inflammation observed in SARS-CoV-2-infected patients suggests that inflammasomes, proinflammatory intracellular complexes, regulate various steps of infection. Lung epithelial cells express inflammasome-forming sensors and constitute the primary entry door of SARS-CoV-2. Here, we describe that the NLRP1 inflammasome detects SARS-CoV-2 infection in human lung epithelial cells. Specifically, human NLRP1 is cleaved at the Q333 site by multiple coronavirus 3CL proteases, which triggers inflammasome assembly and cell death and limits the production of infectious viral particles. Analysis of NLRP1-associated pathways unveils that 3CL proteases also inactivate the pyroptosis executioner Gasdermin D (GSDMD). Subsequently, caspase-3 and GSDME promote alternative cell pyroptosis. Finally, analysis of pyroptosis markers in plasma from COVID-19 patients with characterized severe pneumonia due to autoantibodies against, or inborn errors of, type I interferons (IFNs) highlights GSDME/caspase-3 as potential markers of disease severity. Overall, our findings identify NLRP1 as a sensor of SARS-CoV-2 infection in lung epithelia.


Subject(s)
COVID-19 , Coronavirus 3C Proteases , Epithelial Cells , Inflammasomes , NLR Proteins , SARS-CoV-2 , COVID-19/genetics , COVID-19/metabolism , COVID-19/virology , Caspase 3/metabolism , Coronavirus 3C Proteases/genetics , Coronavirus 3C Proteases/metabolism , Epithelial Cells/metabolism , Humans , Inflammasomes/genetics , Inflammasomes/metabolism , Lung/metabolism , Lung/virology , NLR Proteins/genetics , NLR Proteins/metabolism , Peptide Hydrolases/genetics , Peptide Hydrolases/metabolism , Phosphate-Binding Proteins/genetics , Phosphate-Binding Proteins/metabolism , Pore Forming Cytotoxic Proteins/genetics , Pore Forming Cytotoxic Proteins/metabolism , Pyroptosis , SARS-CoV-2/enzymology , SARS-CoV-2/genetics , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity
8.
J Virol ; 96(11): e0059422, 2022 06 08.
Article in English | MEDLINE | ID: covidwho-1840553

ABSTRACT

It has recently been shown that an early SARS-CoV-2 isolate (NL-02-2020) hijacks interferon-induced transmembrane proteins (IFITMs) for efficient replication in human lung cells, cardiomyocytes, and gut organoids. To date, several "variants of concern" (VOCs) showing increased infectivity and resistance to neutralization have emerged and globally replaced the early viral strains. Here, we determined whether the five current SARS-CoV-2 VOCs (Alpha, Beta, Gamma, Delta, and Omicron) maintained the dependency on IFITM proteins for efficient replication. We found that depletion of IFITM2 strongly reduces viral RNA production by all VOCs in the human epithelial lung cancer cell line Calu-3. Silencing of IFITM1 had modest effects, while knockdown of IFITM3 resulted in an intermediate phenotype. Strikingly, depletion of IFITM2 generally reduced infectious virus production by more than 4 orders of magnitude. In addition, an antibody directed against the N terminus of IFITM2 inhibited SARS-CoV-2 VOC replication in induced pluripotent stem cell (iPSC)-derived alveolar epithelial type II cells, thought to represent major viral target cells in the lung. In conclusion, endogenously expressed IFITM proteins (especially IFITM2) are critical cofactors for efficient replication of genuine SARS-CoV-2 VOCs, including the currently dominant Omicron variant. IMPORTANCE Recent data indicate that SARS-CoV-2 requires endogenously expressed IFITM proteins for efficient infection. However, the results were obtained with an early SARS-CoV-2 isolate. Thus, it remained to be determined whether IFITMs are also important cofactors for infection of emerging SARS-CoV-2 VOCs that outcompeted the original strains in the meantime. This includes the Omicron VOC, which currently dominates the pandemic. Here, we show that depletion of endogenous IFITM2 expression almost entirely prevents productive infection of Alpha, Beta, Gamma, Delta, and Omicron SARS-CoV-2 VOCs in human lung cells. In addition, an antibody targeting the N terminus of IFITM2 inhibited SARS-CoV-2 VOC replication in iPSC-derived alveolar epithelial type II cells. Our results show that SARS-CoV-2 VOCs, including the currently dominant Omicron variant, are strongly dependent on IFITM2 for efficient replication, suggesting a key proviral role of IFITMs in viral transmission and pathogenicity.


Subject(s)
Lung , Membrane Proteins , SARS-CoV-2 , Virus Replication , COVID-19/virology , Cell Line, Tumor , Humans , Lung/virology , Membrane Proteins/genetics , Membrane Proteins/metabolism , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolism , SARS-CoV-2/genetics , SARS-CoV-2/physiology , Virus Internalization
9.
Nature ; 606(7914): 585-593, 2022 06.
Article in English | MEDLINE | ID: covidwho-1815563

ABSTRACT

Severe COVID-19 is characterized by persistent lung inflammation, inflammatory cytokine production, viral RNA and a sustained interferon (IFN) response, all of which are recapitulated and required for pathology in the SARS-CoV-2-infected MISTRG6-hACE2 humanized mouse model of COVID-19, which has a human immune system1-20. Blocking either viral replication with remdesivir21-23 or the downstream IFN-stimulated cascade with anti-IFNAR2 antibodies in vivo in the chronic stages of disease attenuates the overactive immune inflammatory response, especially inflammatory macrophages. Here we show that SARS-CoV-2 infection and replication in lung-resident human macrophages is a critical driver of disease. In response to infection mediated by CD16 and ACE2 receptors, human macrophages activate inflammasomes, release interleukin 1 (IL-1) and IL-18, and undergo pyroptosis, thereby contributing to the hyperinflammatory state of the lungs. Inflammasome activation and the accompanying inflammatory response are necessary for lung inflammation, as inhibition of the NLRP3 inflammasome pathway reverses chronic lung pathology. Notably, this blockade of inflammasome activation leads to the release of infectious virus by the infected macrophages. Thus, inflammasomes oppose host infection by SARS-CoV-2 through the production of inflammatory cytokines and suicide by pyroptosis to prevent a productive viral cycle.


Subject(s)
COVID-19 , Inflammasomes , Macrophages , SARS-CoV-2 , Angiotensin-Converting Enzyme 2 , Animals , COVID-19/pathology , COVID-19/physiopathology , COVID-19/virology , Humans , Inflammasomes/metabolism , Interleukin-1 , Interleukin-18 , Lung/pathology , Lung/virology , Macrophages/metabolism , Macrophages/pathology , Macrophages/virology , Mice , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Pneumonia/metabolism , Pneumonia/virology , Pyroptosis , Receptors, IgG , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity
10.
J Cell Physiol ; 237(7): 2913-2928, 2022 Jul.
Article in English | MEDLINE | ID: covidwho-1802326

ABSTRACT

The COVID-19 disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) primarily affects the lung, particularly the proximal airway and distal alveolar cells. NKX2.1+ primordial lung progenitors of the foregut (anterior) endoderm are the developmental precursors to all adult lung epithelial lineages and are postulated to play an important role in viral tropism. Here, we show that SARS-CoV-2 readily infected and replicated in human-induced pluripotent stem cell-derived proximal airway cells, distal alveolar cells, and lung progenitors. In addition to the upregulation of antiviral defense and immune responses, transcriptomics data uncovered a robust epithelial cell-specific response, including perturbation of metabolic processes and disruption in the alveolar maturation program. We also identified spatiotemporal dysregulation of mitochondrial heme oxygenase 1 (HMOX1), which is associated with defense against antioxidant-induced lung injury. Cytokines, such as TNF-α, INF-γ, IL-6, and IL-13, were upregulated in infected cells sparking mitochondrial ROS production and change in electron transport chain complexes. Increased mitochondrial ROS then activated additional proinflammatory cytokines leading to an aberrant cell cycle resulting in apoptosis. Notably, we are the first to report a chemosensory response resulting from SARS-CoV-2 infection similar to that seen in COVID-19 patients. Some of our key findings were validated using COVID-19-affected postmortem lung tissue sections. These results suggest that our in vitro system could serve as a suitable model to investigate the pathogenetic mechanisms of SARS-CoV-2 infection and to discover and test therapeutic drugs against COVID-19 or its consequences.


Subject(s)
COVID-19 , Induced Pluripotent Stem Cells , Adult , COVID-19/immunology , COVID-19/pathology , Cytokines , Humans , Induced Pluripotent Stem Cells/pathology , Induced Pluripotent Stem Cells/virology , Lung/pathology , Lung/virology , Mitochondria/metabolism , Reactive Oxygen Species , SARS-CoV-2
11.
J Am Soc Nephrol ; 33(7): 1293-1307, 2022 07.
Article in English | MEDLINE | ID: covidwho-1799028

ABSTRACT

BACKGROUND: Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) uses full-length angiotensin converting enzyme 2 (ACE2) as a main receptor to enter target cells. The goal of this study was to demonstrate the preclinical efficacy of a novel soluble ACE2 protein with increased duration of action and binding capacity in a lethal mouse model of COVID-19. METHODS: A human soluble ACE2 variant fused with an albumin binding domain (ABD) was linked via a dimerization motif hinge-like 4-cysteine dodecapeptide (DDC) to improve binding capacity to SARS-CoV-2. This novel soluble ACE2 protein (ACE2-1-618-DDC-ABD) was then administered intranasally and intraperitoneally to mice before intranasal inoculation of SARS-CoV-2 and then for two additional days post viral inoculation. RESULTS: Untreated animals became severely ill, and all had to be humanely euthanized by day 6 or 7 and had pulmonary alveolar hemorrhage with mononuclear infiltrates. In contrast, all but one mouse infected with a lethal dose of SARS-CoV-2 that received ACE2-1-618-DDC-ABD survived. In the animals inoculated with SARS-CoV-2 that were untreated, viral titers were high in the lungs and brain, but viral titers were absent in the kidneys. Some untreated animals, however, had variable degrees of kidney proximal tubular injury as shown by attenuation of the proximal tubular brush border and increased NGAL and TUNEL staining. Viral titers in the lung and brain were reduced or nondetectable in mice that received ACE2-1-618-DDC-ABD, and the animals developed only moderate disease as assessed by a near-normal clinical score, minimal weight loss, and improved lung and kidney injury. CONCLUSIONS: This study demonstrates the preclinical efficacy of a novel soluble ACE2 protein, termed ACE2-1-618-DDC-ABD, in a lethal mouse model of SARS-CoV-2 infection that develops severe lung injury and variable degrees of moderate kidney proximal tubular injury.


Subject(s)
Angiotensin-Converting Enzyme 2 , COVID-19 , Angiotensin-Converting Enzyme 2/therapeutic use , Animals , COVID-19/therapy , Kidney/virology , Lung/virology , Mice , SARS-CoV-2
12.
J Virol ; 96(9): e0003822, 2022 05 11.
Article in English | MEDLINE | ID: covidwho-1788914

ABSTRACT

Due to the limitation of human studies with respect to individual difference or the accessibility of fresh tissue samples, how severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection results in pathological complications in lung, the main site of infection, is still incompletely understood. Therefore, physiologically relevant animal models under realistic SARS-CoV-2 infection conditions would be helpful to our understanding of dysregulated inflammation response in lung in the context of targeted therapeutics. Here, we characterized the single-cell landscape in lung and spleen upon SARS-CoV-2 infection in an acute severe disease mouse model that replicates human symptoms, including severe lung pathology and lymphopenia. We showed a reduction of lymphocyte populations and an increase of neutrophils in lung and then demonstrated the key role of neutrophil-mediated lung immunopathology in both mice and humans. Under severe conditions, neutrophils recruited by a chemokine-driven positive feedback produced elevated "fatal signature" proinflammatory genes and pathways related to neutrophil activation or releasing of granular content. In addition, we identified a new Cd177high cluster that is undergoing respiratory burst and Stfahigh cluster cells that may dampen antigen presentation upon infection. We also revealed the devastating effect of overactivated neutrophil by showing the highly enriched neutrophil extracellular traps in lung and a dampened B-cell function in either lung or spleen that may be attributed to arginine consumption by neutrophil. The current study helped our understanding of SARS-CoV-2-induced pneumonia and warranted the concept of neutrophil-targeting therapeutics in COVID-19 treatment. IMPORTANCE We demonstrated the single-cell landscape in lung and spleen upon SARS-CoV-2 infection in an acute severe disease mouse model that replicated human symptoms, including severe lung pathology and lymphopenia. Our comprehensive study revealed the key role of neutrophil-mediated lung immunopathology in SARS-CoV-2-induced severe pneumonia, which not only helped our understanding of COVID-19 but also warranted the concept of neutrophil targeting therapeutics in COVID-19 treatment.


Subject(s)
COVID-19 , Lung , Neutrophils , Animals , COVID-19/immunology , Disease Models, Animal , Humans , Lung/pathology , Lung/virology , Lymphopenia/virology , Mice , Neutrophils/immunology , SARS-CoV-2 , Spleen/pathology , Spleen/virology
13.
Can J Anaesth ; 67(10): 1393-1404, 2020 10.
Article in English | MEDLINE | ID: covidwho-1777843

ABSTRACT

Pulmonary complications are the most common clinical manifestations of coronavirus disease (COVID-19). From recent clinical observation, two phenotypes have emerged: a low elastance or L-type and a high elastance or H-type. Clinical presentation, pathophysiology, pulmonary mechanics, radiological and ultrasound findings of these two phenotypes are different. Consequently, the therapeutic approach also varies between the two. We propose a management algorithm that combines the respiratory rate and oxygenation index with bedside lung ultrasound examination and monitoring that could help determine earlier the requirement for intubation and other surveillance of COVID-19 patients with respiratory failure.


RéSUMé: Les complications pulmonaires du coronavirus (COVID-19) constituent ses manifestations cliniques les plus fréquentes. De récentes observations cliniques ont fait émerger deux phénotypes : le phénotype à élastance faible ou type L (low), et le phénotype à élastance élevée, ou type H (high). La présentation clinique, la physiopathologie, les mécanismes pulmonaires, ainsi que les observations radiologiques et échographiques de ces deux différents phénotypes sont différents. L'approche thérapeutique variera par conséquent selon le phénotype des patients atteints de COVID-19 souffrant d'insuffisance respiratoire.


Subject(s)
Coronavirus Infections/complications , Lung/diagnostic imaging , Pneumonia, Viral/complications , Respiratory Insufficiency/diagnostic imaging , Ultrasonography , Acute Disease , Algorithms , COVID-19 , Coronavirus Infections/diagnostic imaging , Humans , Lung/physiopathology , Lung/virology , Oxygen/metabolism , Pandemics , Phenotype , Pneumonia, Viral/diagnostic imaging , Point-of-Care Systems , Respiratory Insufficiency/virology , Respiratory Rate/physiology
15.
Nature ; 603(7902): 706-714, 2022 03.
Article in English | MEDLINE | ID: covidwho-1764186

ABSTRACT

The SARS-CoV-2 Omicron BA.1 variant emerged in 20211 and has multiple mutations in its spike protein2. Here we show that the spike protein of Omicron has a higher affinity for ACE2 compared with Delta, and a marked change in its antigenicity increases Omicron's evasion of therapeutic monoclonal and vaccine-elicited polyclonal neutralizing antibodies after two doses. mRNA vaccination as a third vaccine dose rescues and broadens neutralization. Importantly, the antiviral drugs remdesivir and molnupiravir retain efficacy against Omicron BA.1. Replication was similar for Omicron and Delta virus isolates in human nasal epithelial cultures. However, in lung cells and gut cells, Omicron demonstrated lower replication. Omicron spike protein was less efficiently cleaved compared with Delta. The differences in replication were mapped to the entry efficiency of the virus on the basis of spike-pseudotyped virus assays. The defect in entry of Omicron pseudotyped virus to specific cell types effectively correlated with higher cellular RNA expression of TMPRSS2, and deletion of TMPRSS2 affected Delta entry to a greater extent than Omicron. Furthermore, drug inhibitors targeting specific entry pathways3 demonstrated that the Omicron spike inefficiently uses the cellular protease TMPRSS2, which promotes cell entry through plasma membrane fusion, with greater dependency on cell entry through the endocytic pathway. Consistent with suboptimal S1/S2 cleavage and inability to use TMPRSS2, syncytium formation by the Omicron spike was substantially impaired compared with the Delta spike. The less efficient spike cleavage of Omicron at S1/S2 is associated with a shift in cellular tropism away from TMPRSS2-expressing cells, with implications for altered pathogenesis.


Subject(s)
COVID-19/pathology , COVID-19/virology , Membrane Fusion , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity , Serine Endopeptidases/metabolism , Virus Internalization , Adult , Aged , Aged, 80 and over , Angiotensin-Converting Enzyme 2/metabolism , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/immunology , COVID-19 Vaccines/immunology , Cell Line , Cell Membrane/metabolism , Cell Membrane/virology , Chlorocebus aethiops , Convalescence , Female , Humans , Immune Sera/immunology , Intestines/pathology , Intestines/virology , Lung/pathology , Lung/virology , Male , Middle Aged , Mutation , Nasal Mucosa/pathology , Nasal Mucosa/virology , SARS-CoV-2/drug effects , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism , Tissue Culture Techniques , Virulence , Virus Replication
17.
Signal Transduct Target Ther ; 7(1): 61, 2022 02 25.
Article in English | MEDLINE | ID: covidwho-1758178

ABSTRACT

Variants are globally emerging very quickly following pandemic prototypic SARS-CoV-2. To evaluate the cross-protection of prototypic SARS-CoV-2 vaccine against its variants, we vaccinated rhesus monkeys with three doses of prototypic SARS-CoV-2 inactivated vaccine, followed by challenging with emerging SARS-CoV-2 variants of concern (VOCs). These vaccinated animals produced neutralizing antibodies against Alpha, Beta, Delta, and Omicron variants, although there were certain declinations of geometric mean titer (GMT) as compared with prototypic SARS-CoV-2. Of note, in vivo this prototypic vaccine not only reduced the viral loads in nasal, throat and anal swabs, pulmonary tissues, but also improved the pathological changes in the lung infected by variants of Alpha, Beta, and Delta. In summary, the prototypic SARS-CoV-2 inactivated vaccine in this study protected against VOCs to certain extension, which is of great significance for prevention and control of COVID-19.


Subject(s)
Antibodies, Neutralizing/biosynthesis , Antibodies, Viral/biosynthesis , COVID-19 Vaccines/administration & dosage , COVID-19/prevention & control , Cross Protection , SARS-CoV-2/drug effects , Vaccination/methods , Vaccines, Inactivated/administration & dosage , Anal Canal/virology , Animals , B-Lymphocytes/immunology , B-Lymphocytes/virology , COVID-19/immunology , COVID-19/virology , Humans , Immunogenicity, Vaccine , Lung/virology , Macaca mulatta , Male , Nasal Cavity/virology , Pharynx/virology , SARS-CoV-2/growth & development , SARS-CoV-2/pathogenicity , T-Lymphocytes/immunology , T-Lymphocytes/virology , Viral Load/drug effects
18.
Commun Biol ; 5(1): 242, 2022 03 18.
Article in English | MEDLINE | ID: covidwho-1751765

ABSTRACT

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the cause of coronavirus disease 2019 (COVID-19), has incited a global health crisis. Currently, there are limited therapeutic options for the prevention and treatment of SARS-CoV-2 infections. We evaluated the antiviral activity of sulforaphane (SFN), the principal biologically active phytochemical derived from glucoraphanin, the naturally occurring precursor present in high concentrations in cruciferous vegetables. SFN inhibited in vitro replication of six strains of SARS-CoV-2, including Delta and Omicron, as well as that of the seasonal coronavirus HCoV-OC43. Further, SFN and remdesivir interacted synergistically to inhibit coronavirus infection in vitro. Prophylactic administration of SFN to K18-hACE2 mice prior to intranasal SARS-CoV-2 infection significantly decreased the viral load in the lungs and upper respiratory tract and reduced lung injury and pulmonary pathology compared to untreated infected mice. SFN treatment diminished immune cell activation in the lungs, including significantly lower recruitment of myeloid cells and a reduction in T cell activation and cytokine production. Our results suggest that SFN should be explored as a potential agent for the prevention or treatment of coronavirus infections.


Subject(s)
Antiviral Agents/therapeutic use , Common Cold/drug therapy , Coronavirus Infections/drug therapy , Coronavirus OC43, Human , Isothiocyanates/therapeutic use , SARS-CoV-2 , Sulfoxides/therapeutic use , Adenosine Monophosphate/analogs & derivatives , Adenosine Monophosphate/therapeutic use , Alanine/analogs & derivatives , Alanine/therapeutic use , Animals , COVID-19/drug therapy , Caco-2 Cells , Chlorocebus aethiops , Common Cold/virology , Coronavirus Infections/immunology , Coronavirus Infections/virology , Cytokines/immunology , Drug Synergism , Humans , Lung/immunology , Lung/virology , Macrophages, Alveolar/immunology , Male , Mice, Transgenic , Spleen/immunology , T-Lymphocytes/immunology , Vero Cells , Viral Load
19.
Commun Biol ; 5(1): 225, 2022 03 10.
Article in English | MEDLINE | ID: covidwho-1740485

ABSTRACT

Late 2020, SARS-CoV-2 Alpha variant emerged in United Kingdom and gradually replaced G614 strains initially involved in the global spread of the pandemic. In this study, we use a Syrian hamster model to compare a clinical strain of Alpha variant with an ancestral G614 strain. The Alpha variant succeed to infect animals and to induce a pathology that mimics COVID-19. However, both strains replicate to almost the same level and induced a comparable disease and immune response. A slight fitness advantage is noted for the G614 strain during competition and transmission experiments. These data do not corroborate the epidemiological situation observed during the first half of 2021 in humans nor reports that showed a more rapid replication of Alpha variant in human reconstituted bronchial epithelium. This study highlights the need to combine data from different laboratories using various animal models to decipher the biological properties of newly emerging SARS-CoV-2 variants.


Subject(s)
COVID-19 , Disease Models, Animal , Mesocricetus , SARS-CoV-2/physiology , Animals , Antibodies, Neutralizing/blood , COVID-19/blood , COVID-19/immunology , COVID-19/virology , Cytokines/genetics , Female , Gastrointestinal Tract/virology , Genome, Viral , Lung/virology , Nasal Lavage Fluid/virology , SARS-CoV-2/genetics , Virus Replication
20.
Sci Rep ; 12(1): 4150, 2022 03 09.
Article in English | MEDLINE | ID: covidwho-1735291

ABSTRACT

Models of animals that are susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can usefully evaluate the efficacy of vaccines and therapeutics. In this study, we demonstrate that infection with the SARS-CoV-2 B.1.351 variant (TY8-612 strain) induces bodyweight loss and inflammatory cytokine/chemokine production in wild-type laboratory mice (BALB/c and C57BL/6 J mice). Furthermore, compared to their counterparts, BALB/c mice had a higher viral load in their lungs and worse symptoms. Importantly, infecting aged BALB/c mice (older than 6 months) with the TY8-612 strain elicited a massive and sustained production of multiple pro-inflammatory cytokines/chemokines and led to universal mortality. These results indicated that the SARS-CoV-2 B.1.351 variant-infected mice exhibited symptoms ranging from mild to fatal depending on their strain and age. Our data provide insights into the pathogenesis of SARS-CoV-2 and may be useful in developing prophylactics and therapeutics.


Subject(s)
COVID-19/pathology , SARS-CoV-2/physiology , Aging , Animals , COVID-19/mortality , COVID-19/virology , Chemokines/metabolism , Cytokines/metabolism , Disease Models, Animal , Lung/pathology , Lung/virology , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Principal Component Analysis , RNA, Viral/metabolism , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , Severity of Illness Index , Viral Load
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