Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 52
Filter
1.
PLoS One ; 17(1): e0262179, 2022.
Article in English | MEDLINE | ID: covidwho-1636037

ABSTRACT

Comparisons of histopathological features and microbiological findings between decedents with respiratory symptoms due to SARS-CoV-2 infection or other causes, in settings with high prevalence of HIV and Mycobacterium tuberculosis (MTB) infections have not been reported. Deaths associated with a positive ante-mortem SARS-CoV-2 PCR test and/or respiratory disease symptoms at Chris Hani Baragwanath Academic Hospital in Soweto, South Africa from 15th April to 2nd November 2020, during the first wave of the South African COVID-19 epidemic, were investigated. Deceased adult patients had post-mortem minimally-invasive tissue sampling (MITS) performed to investigate for SARS-CoV-2 infection and molecular detection of putative pathogens on blood and lung samples, and histopathology examination of lung, liver and heart tissue. During the study period MITS were done in patients displaying symptoms of respiratory disease including 75 COVID-19-related deaths (COVID+) and 42 non-COVID-19-related deaths (COVID-). The prevalence of HIV-infection was lower in COVID+ (27%) than in the COVID- (64%), MTB detection was also less common among COVID+ (3% vs 13%). Lung histopathology findings showed differences between COVID+ and COVID- in the severity of the morphological appearance of Type-II pneumocytes, alveolar injury and repair initiated by SARS-CoV-2 infection. In the liver necrotising granulomatous inflammation was more common among COVID+. No differences were found in heart analyses. The prevalence of bacterial co-infections was higher in COVID+. Most indicators of respiratory distress syndrome were undifferentiated between COVID+ and COVID- except for Type-II pneumocytes. HIV or MTB infection does not appear in these data to have a meaningful correspondence with COVID-related deaths.


Subject(s)
Alveolar Epithelial Cells/pathology , COVID-19/epidemiology , COVID-19/mortality , Diabetes Mellitus/epidemiology , Hypertension/epidemiology , Pandemics , SARS-CoV-2/genetics , Adult , Aged , Autopsy , Biopsy, Large-Core Needle/methods , COVID-19/pathology , COVID-19/virology , COVID-19 Nucleic Acid Testing/methods , Comorbidity , Female , Humans , Length of Stay , Male , Middle Aged , Real-Time Polymerase Chain Reaction/methods , South Africa/epidemiology
2.
J Exp Med ; 219(2)2022 02 07.
Article in English | MEDLINE | ID: covidwho-1594167

ABSTRACT

In rare instances, pediatric SARS-CoV-2 infection results in a novel immunodysregulation syndrome termed multisystem inflammatory syndrome in children (MIS-C). We compared MIS-C immunopathology with severe COVID-19 in adults. MIS-C does not result in pneumocyte damage but is associated with vascular endotheliitis and gastrointestinal epithelial injury. In MIS-C, the cytokine release syndrome is characterized by IFNγ and not type I interferon. Persistence of patrolling monocytes differentiates MIS-C from severe COVID-19, which is dominated by HLA-DRlo classical monocytes. IFNγ levels correlate with granzyme B production in CD16+ NK cells and TIM3 expression on CD38+/HLA-DR+ T cells. Single-cell TCR profiling reveals a skewed TCRß repertoire enriched for TRBV11-2 and a superantigenic signature in TIM3+/CD38+/HLA-DR+ T cells. Using NicheNet, we confirm IFNγ as a central cytokine in the communication between TIM3+/CD38+/HLA-DR+ T cells, CD16+ NK cells, and patrolling monocytes. Normalization of IFNγ, loss of TIM3, quiescence of CD16+ NK cells, and contraction of patrolling monocytes upon clinical resolution highlight their potential role in MIS-C immunopathogenesis.


Subject(s)
COVID-19/complications , Hepatitis A Virus Cellular Receptor 2/metabolism , Interferon-gamma/metabolism , Killer Cells, Natural/immunology , Monocytes/metabolism , Receptors, IgG/metabolism , Systemic Inflammatory Response Syndrome/immunology , T-Lymphocytes/immunology , Adolescent , Alveolar Epithelial Cells/pathology , B-Lymphocytes/immunology , Blood Vessels/pathology , COVID-19/immunology , COVID-19/pathology , Cell Proliferation , Child , Cohort Studies , Complement Activation , Cytokines/metabolism , Enterocytes/pathology , Female , Humans , Immunity, Humoral , Inflammation/pathology , Interferon Type I/metabolism , Interleukin-15/metabolism , Lymphocyte Activation/immunology , Male , Receptors, Antigen, T-Cell/metabolism , SARS-CoV-2/immunology , Superantigens/metabolism , Systemic Inflammatory Response Syndrome/pathology
3.
Nat Cell Biol ; 23(12): 1314-1328, 2021 12.
Article in English | MEDLINE | ID: covidwho-1559292

ABSTRACT

The lung is the primary organ targeted by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), making respiratory failure a leading coronavirus disease 2019 (COVID-19)-related mortality. However, our cellular and molecular understanding of how SARS-CoV-2 infection drives lung pathology is limited. Here we constructed multi-omics and single-nucleus transcriptomic atlases of the lungs of patients with COVID-19, which integrate histological, transcriptomic and proteomic analyses. Our work reveals the molecular basis of pathological hallmarks associated with SARS-CoV-2 infection in different lung and infiltrating immune cell populations. We report molecular fingerprints of hyperinflammation, alveolar epithelial cell exhaustion, vascular changes and fibrosis, and identify parenchymal lung senescence as a molecular state of COVID-19 pathology. Moreover, our data suggest that FOXO3A suppression is a potential mechanism underlying the fibroblast-to-myofibroblast transition associated with COVID-19 pulmonary fibrosis. Our work depicts a comprehensive cellular and molecular atlas of the lungs of patients with COVID-19 and provides insights into SARS-CoV-2-related pulmonary injury, facilitating the identification of biomarkers and development of symptomatic treatments.


Subject(s)
COVID-19/genetics , Lung/metabolism , Transcriptome/genetics , Alveolar Epithelial Cells/metabolism , Alveolar Epithelial Cells/pathology , Alveolar Epithelial Cells/virology , COVID-19/metabolism , Fibrosis/metabolism , Fibrosis/pathology , Fibrosis/virology , Humans , Lung/pathology , Lung/virology , Proteomics/methods , SARS-CoV-2/pathogenicity
4.
Emerg Microbes Infect ; 10(1): 2194-2198, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1504286

ABSTRACT

Inactivated coronaviruses, including severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1) and Middle East respiratory syndrome coronavirus (MERS-CoV), as potential vaccines have been reported to result in enhanced respiratory diseases (ERDs) in murine and nonhuman primate (NHP) pneumonia models after virus challenge, which poses great safety concerns of antibody-dependent enhancement (ADE) for the rapid wide application of inactivated SARS-CoV-2 vaccines in humans, especially when the neutralizing antibody levels induced by vaccination or initial infection quickly wane to nonneutralizing or subneutralizing levels over the time. With passive transfer of diluted postvaccination polyclonal antibodies to mimic the waning antibody responses after vaccination, we found that in the absence of cellular immunity, passive infusion of subneutralizing or nonneutralizing anti-SARS-CoV-2 antibodies could still provide some level of protection against infection upon challenge, and no low-level antibody-enhanced infection was observed. The anti-SARS-CoV-2 IgG-infused group and control group showed similar, mild to moderate pulmonary immunopathology during the acute phase of virus infection, and no evidence of vaccine-related pulmonary immunopathology enhancement was found. Typical immunopathology included elevated MCP-1, IL-8 and IL-33 in bronchoalveolar lavage fluid; alveolar epithelial hyperplasia; and exfoliated cells and mucus in bronchioles. Our results corresponded with the recent observations that no pulmonary immunology was detected in preclinical studies of inactivated SARS-CoV-2 vaccines in either murine or NHP pneumonia models or in large clinical trials and further supported the safety of inactivated SARS-CoV-2 vaccines.


Subject(s)
Antibodies, Viral/immunology , Antibody-Dependent Enhancement , COVID-19 Vaccines/immunology , COVID-19/immunology , Immunogenicity, Vaccine , SARS-CoV-2/immunology , Alveolar Epithelial Cells/pathology , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/toxicity , Bronchioles/chemistry , Bronchioles/pathology , Bronchoalveolar Lavage Fluid/chemistry , Bronchoalveolar Lavage Fluid/immunology , COVID-19/pathology , COVID-19/virology , Cytokines/analysis , Humans , Hyperplasia , Immunoglobulin G/immunology , Immunoglobulin G/toxicity , Lung/pathology , Macaca mulatta , Male , Mice , Mucus , SARS-CoV-2/isolation & purification , SARS-CoV-2/physiology , Vaccines, Inactivated/immunology
5.
Sci Rep ; 11(1): 19342, 2021 09 29.
Article in English | MEDLINE | ID: covidwho-1442803

ABSTRACT

Coronavirus disease 19 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a global pandemic with significant mortality. Accurate information on the specific circumstances of death and whether patients died from or with SARS-CoV-2 is scarce. To distinguish COVID-19 from non-COVID-19 deaths, we performed a systematic review of 735 SARS-CoV-2-associated deaths in Hamburg, Germany, from March to December 2020, using conventional autopsy, ultrasound-guided minimally invasive autopsy, postmortem computed tomography and medical records. Statistical analyses including multiple logistic regression were used to compare both cohorts. 84.1% (n = 618) were classified as COVID-19 deaths, 6.4% (n = 47) as non-COVID-19 deaths, 9.5% (n = 70) remained unclear. Median age of COVID-19 deaths was 83.0 years, 54.4% were male. In the autopsy group (n = 283), the majority died of pneumonia and/or diffuse alveolar damage (73.6%; n = 187). Thromboses were found in 39.2% (n = 62/158 cases), pulmonary embolism in 22.1% (n = 56/253 cases). In 2020, annual mortality in Hamburg was about 5.5% higher than in the previous 20 years, of which 3.4% (n = 618) represented COVID-19 deaths. Our study highlights the need for mortality surveillance and postmortem examinations. The vast majority of individuals who died directly from SARS-CoV-2 infection were of advanced age and had multiple comorbidities.


Subject(s)
Autopsy , COVID-19 , Comorbidity , Adult , Age Factors , Aged , Aged, 80 and over , Alveolar Epithelial Cells/pathology , Alveolar Epithelial Cells/virology , COVID-19/diagnosis , COVID-19/epidemiology , Female , Germany/epidemiology , Humans , Lung/pathology , Male , Middle Aged , Mortality , Pneumonia , Prospective Studies , Pulmonary Embolism , SARS-CoV-2 , Thrombosis
6.
Biochem Biophys Res Commun ; 577: 146-151, 2021 11 05.
Article in English | MEDLINE | ID: covidwho-1401239

ABSTRACT

The human lung cell A549 is susceptible to infection with a number of respiratory viruses. However, A549 cells are resistant to Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) infection in conventional submerged culture, and this would appear to be due to low expression levels of the SARS-CoV-2 entry receptor: angiotensin-converting enzyme-2 (ACE2). Here, we examined SARS-CoV-2 susceptibility to A549 cells after adaptation to air-liquid interface (ALI) culture. A549 cells in ALI culture yielded a layer of mucus on their apical surface, exhibited decreased expression levels of the proliferation marker KI-67 and intriguingly became susceptible to SARS-CoV-2 infection. We found that A549 cells increased the endogenous expression levels of ACE2 and TMPRSS2 following adaptation to ALI culture conditions. Camostat, a TMPRSS2 inhibitor, reduced SARS-CoV-2 infection in ALI-cultured A549 cells. These findings indicate that ALI culture switches the phenotype of A549 cells from resistance to susceptibility to SARS-CoV-2 infection through upregulation of ACE2 and TMPRSS2.


Subject(s)
Alveolar Epithelial Cells/virology , COVID-19/virology , Cell Culture Techniques/methods , SARS-CoV-2/physiology , A549 Cells , Alveolar Epithelial Cells/pathology , Cells, Cultured , Disease Susceptibility , Gene Expression Regulation, Neoplastic , Humans , Peptidyl-Dipeptidase A/genetics , Peptidyl-Dipeptidase A/metabolism , Serine Endopeptidases/genetics , Serine Endopeptidases/metabolism , Up-Regulation/genetics
7.
Mol Med Rep ; 24(4)2021 Oct.
Article in English | MEDLINE | ID: covidwho-1395036

ABSTRACT

Chronic alcohol abuse increases the risk of mortality and poor outcomes in patients with acute respiratory distress syndrome. However, the underlying mechanisms remain to be elucidated. The present study aimed to investigate the effects of chronic alcohol consumption on lung injury and clarify the signaling pathways involved in the inhibition of alveolar fluid clearance (AFC). In order to produce rodent models with chronic alcohol consumption, wild­type C57BL/6 mice were treated with alcohol. A2a adenosine receptor (AR) small interfering (si)RNA or A2bAR siRNA were transfected into the lung tissue of mice and primary rat alveolar type II (ATII) cells. The rate of AFC in lung tissue was measured during exposure to lipopolysaccharide (LPS). Epithelial sodium channel (ENaC) expression was determined to investigate the mechanisms underlying alcohol­induced regulation of AFC. In the present study, exposure to alcohol reduced AFC, exacerbated pulmonary edema and worsened LPS­induced lung injury. Alcohol caused a decrease in cyclic adenosine monophosphate (cAMP) levels and inhibited α­ENaC, ß­ENaC and γ­ENaC expression levels in the lung tissue of mice and ATII cells. Furthermore, alcohol decreased α­ENaC, ß­ENaC and γ­ENaC expression levels via the A2aAR or A2bAR­cAMP signaling pathways in vitro. In conclusion, the results of the present study demonstrated that chronic alcohol consumption worsened lung injury by aggravating pulmonary edema and impairing AFC. An alcohol­induced decrease of α­ENaC, ß­ENaC and γ­ENaC expression levels by the A2AR­mediated cAMP pathway may be responsible for the exacerbated effects of chronic alcohol consumption in lung injury.


Subject(s)
Acute Lung Injury/metabolism , Alveolar Epithelial Cells/metabolism , Epithelial Sodium Channels/drug effects , Epithelial Sodium Channels/metabolism , Ethanol/pharmacology , Receptors, Adenosine A2/metabolism , Acute Lung Injury/chemically induced , Acute Lung Injury/pathology , Alveolar Epithelial Cells/pathology , Animals , Cyclic AMP/metabolism , Cytokines , Lipopolysaccharides/adverse effects , Lung/metabolism , Lung Injury/chemically induced , Lung Injury/metabolism , Lung Injury/pathology , Mice , Mice, Inbred C57BL , Pulmonary Alveoli/metabolism , Pulmonary Edema/chemically induced , Pulmonary Edema/metabolism , Pulmonary Edema/pathology , RNA Splicing Factors/genetics , RNA Splicing Factors/metabolism , Rats , Receptor, Adenosine A2A/genetics , Receptor, Adenosine A2A/metabolism , Signal Transduction
8.
Int J Mol Sci ; 22(5)2021 Mar 04.
Article in English | MEDLINE | ID: covidwho-1389392

ABSTRACT

Alveolar type II (ATII) cells are a key structure of the distal lung epithelium, where they exert their innate immune response and serve as progenitors of alveolar type I (ATI) cells, contributing to alveolar epithelial repair and regeneration. In the healthy lung, ATII cells coordinate the host defense mechanisms, not only generating a restrictive alveolar epithelial barrier, but also orchestrating host defense mechanisms and secreting surfactant proteins, which are important in lung protection against pathogen exposure. Moreover, surfactant proteins help to maintain homeostasis in the distal lung and reduce surface tension at the pulmonary air-liquid interface, thereby preventing atelectasis and reducing the work of breathing. ATII cells may also contribute to the fibroproliferative reaction by secreting growth factors and proinflammatory molecules after damage. Indeed, various acute and chronic diseases are associated with intensive inflammation. These include oedema, acute respiratory distress syndrome, fibrosis and numerous interstitial lung diseases, and are characterized by hyperplastic ATII cells which are considered an essential part of the epithelialization process and, consequently, wound healing. The aim of this review is that of revising the physiologic and pathologic role ATII cells play in pulmonary diseases, as, despite what has been learnt in the last few decades of research, the origin, phenotypic regulation and crosstalk of these cells still remain, in part, a mystery.


Subject(s)
Alveolar Epithelial Cells/pathology , Alveolar Epithelial Cells/physiology , Lung Diseases/physiopathology , Lung/physiology , Alveolar Epithelial Cells/cytology , Animals , COVID-19/physiopathology , Humans , Immunity, Innate , Ions/metabolism , Lung/anatomy & histology , Lung Diseases/etiology , Lung Diseases/pathology , Pulmonary Surfactant-Associated Proteins/metabolism , Regeneration
9.
J Toxicol Sci ; 46(9): 425-435, 2021.
Article in English | MEDLINE | ID: covidwho-1389030

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19). SARS-CoV-2 enters host cells by binding with the receptor angiotensin-converting enzyme 2 (ACE2). While ACE2 is expressed in multiple cell types, it has been implicated in the clinical progression of COVID-19 as an entry point for SARS-CoV-2 into respiratory cells. Human respiratory cells, such as airway and alveolar epithelial type II (ATII) cells, are considered essential for COVID-19 research; however, primary human respiratory cells are difficult to obtain. In the present study, we generated ATII and club cells from human induced pluripotent stem cells (hiPSCs) for SARS-CoV-2 infection and drug testing. The differentiated cells expressed ATII markers (SFTPB, SFTPC, ABCA3, SLC34A2) or club cell markers (SCGB1A1 and SCGB3A2). Differentiated cells, which express ACE2 and TMPRSS2, were infected with SARS-CoV-2. Remdesivir treatment decreased intracellular SARS-CoV-2 viral replication and, furthermore, treatment with bleomycin showed cytotoxicity in a concentration-dependent manner. These data suggest that hiPSC-derived AT2 and club cells provide a useful in vitro model for drug development.


Subject(s)
Adenosine Monophosphate/analogs & derivatives , Alanine/analogs & derivatives , Alveolar Epithelial Cells/drug effects , Antiviral Agents/pharmacology , Bleomycin/toxicity , Cell Differentiation , Induced Pluripotent Stem Cells/drug effects , SARS-CoV-2/drug effects , Toxicity Tests , Adenosine Monophosphate/pharmacology , Alanine/pharmacology , Alveolar Epithelial Cells/metabolism , Alveolar Epithelial Cells/pathology , Alveolar Epithelial Cells/virology , COVID-19/drug therapy , Cell Line , Cell Survival/drug effects , Host-Pathogen Interactions , Humans , Induced Pluripotent Stem Cells/metabolism , Induced Pluripotent Stem Cells/pathology , Induced Pluripotent Stem Cells/virology , Phenotype , SARS-CoV-2/growth & development , SARS-CoV-2/pathogenicity , Virus Replication/drug effects
10.
Nature ; 583(7818): 834-838, 2020 07.
Article in English | MEDLINE | ID: covidwho-1387423

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel coronavirus with high nucleotide identity to SARS-CoV and to SARS-related coronaviruses that have been detected in horseshoe bats, has spread across the world and had a global effect on healthcare systems and economies1,2. A suitable small animal model is needed to support the development of vaccines and therapies. Here we report the pathogenesis and transmissibility of SARS-CoV-2 in golden (Syrian) hamsters (Mesocricetus auratus). Immunohistochemistry assay demonstrated the presence of viral antigens in nasal mucosa, bronchial epithelial cells and areas of lung consolidation on days 2 and 5 after inoculation with SARS-CoV-2, followed by rapid viral clearance and pneumocyte hyperplasia at 7 days after inoculation. We also found viral antigens in epithelial cells of the duodenum, and detected viral RNA in faeces. Notably, SARS-CoV-2 was transmitted efficiently from inoculated hamsters to naive hamsters by direct contact and via aerosols. Transmission via fomites in soiled cages was not as efficient. Although viral RNA was continuously detected in the nasal washes of inoculated hamsters for 14 days, the communicable period was short and correlated with the detection of infectious virus but not viral RNA. Inoculated and naturally infected hamsters showed apparent weight loss on days 6-7 post-inoculation or post-contact; all hamsters returned to their original weight within 14 days and developed neutralizing antibodies. Our results suggest that features associated with SARS-CoV-2 infection in golden hamsters resemble those found in humans with mild SARS-CoV-2 infections.


Subject(s)
Betacoronavirus/pathogenicity , Coronavirus Infections/transmission , Coronavirus Infections/virology , Disease Models, Animal , Lung/pathology , Lung/virology , Mesocricetus/virology , Pneumonia, Viral/transmission , Pneumonia, Viral/virology , Aerosols , Alveolar Epithelial Cells/pathology , Alveolar Epithelial Cells/virology , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Antigens, Viral/immunology , Antigens, Viral/isolation & purification , Antigens, Viral/metabolism , Betacoronavirus/immunology , Betacoronavirus/isolation & purification , Betacoronavirus/metabolism , Bronchi/pathology , Bronchi/virology , COVID-19 , Coronavirus Infections/immunology , Duodenum/virology , Fomites/virology , Housing, Animal , Kidney/virology , Male , Mesocricetus/immunology , Nasal Mucosa/virology , Pandemics , Pneumonia, Viral/immunology , RNA, Viral/analysis , SARS-CoV-2 , Viral Load , Weight Loss
11.
Cell Stress Chaperones ; 26(5): 859-868, 2021 09.
Article in English | MEDLINE | ID: covidwho-1353732

ABSTRACT

Vaccinations are widely credited with reducing death rates from COVID-19, but the underlying host-viral mechanisms/interactions for morbidity and mortality of SARS-CoV-2 infection remain poorly understood. Acute respiratory distress syndrome (ARDS) describes the severe lung injury, which is pathologically associated with alveolar damage, inflammation, non-cardiogenic edema, and hyaline membrane formation. Because proteostatic pathways play central roles in cellular protection, immune modulation, protein degradation, and tissue repair, we examined the pathological features for the unfolded protein response (UPR) using the surrogate biomarker glucose-regulated protein 78 (GRP78) and co-receptor for SARS-CoV-2. At autopsy, immunostaining of COVID-19 lungs showed highly elevated expression of GRP78 in both pneumocytes and macrophages compared with that of non-COVID control lungs. GRP78 expression was detected in both SARS-CoV-2-infected and un-infected pneumocytes as determined by multiplexed immunostaining for nucleocapsid protein. In macrophages, immunohistochemical staining for GRP78 from deceased COVID-19 patients was increased but overlapped with GRP78 expression taken from surgical resections of non-COVID-19 controls. In contrast, the robust in situ GRP78 immunostaining of pneumocytes from COVID-19 autopsies exhibited no overlap and was independent of age, race/ethnicity, and gender compared with that from non-COVID-19 controls. Our findings bring new insights for stress-response pathways involving the proteostatic network implicated for host resilience and suggest that targeting of GRP78 expression with existing therapeutics might afford an alternative therapeutic strategy to modulate host-viral interactions during SARS-CoV-2 infections.


Subject(s)
Alveolar Epithelial Cells/metabolism , COVID-19/metabolism , Endoplasmic Reticulum Stress , Heat-Shock Proteins/analysis , Receptors, Coronavirus/analysis , SARS-CoV-2/pathogenicity , Adult , Aged , Aged, 80 and over , Alveolar Epithelial Cells/pathology , Alveolar Epithelial Cells/virology , Autopsy , COVID-19/mortality , COVID-19/pathology , COVID-19/virology , Case-Control Studies , Female , Host-Pathogen Interactions , Humans , Macrophages, Alveolar/metabolism , Macrophages, Alveolar/virology , Male , Middle Aged , Proteostasis , Up-Regulation , Young Adult
12.
Front Immunol ; 12: 660632, 2021.
Article in English | MEDLINE | ID: covidwho-1325522

ABSTRACT

The novel SARS-CoV-2virus that caused the disease COVID-19 is currently a pandemic worldwide. The virus requires an alveolar type-2 pneumocyte in the host to initiate its life cycle. The viral S1 spike protein helps in the attachment of the virus on toACE-2 receptors present on type-2 pneumocytes, and the S2 spike protein helps in the fusion of the viral membrane with the host membrane. Fusion of the SARS-CoV-2virus and host membrane is followed by entry of viral RNA into the host cells which is directly translated into the replicase-transcriptase complex (RTC) following viral RNA and structural protein syntheses. As the virus replicates within type-2 pneumocytes, the host immune system is activated and alveolar macrophages start secreting cytokines and chemokines, acting as an inflammatory mediator, and chemotactic neutrophils, monocytes, natural NK cells, and CD8+ T cells initiate the local phagocytosis of infected cells. It is not the virus that kills COVID-19 patients; instead, the aberrant host immune response kills them. Modifying the response from the host immune system could reduce the high mortality due to SARS-CoV-2 infection. The present study examines the viral life cycle intype-2 pneumocytes and resultant host immune response along with possible therapeutic targets.


Subject(s)
COVID-19/immunology , COVID-19/therapy , Immunomodulation , SARS-CoV-2/pathogenicity , Alveolar Epithelial Cells/metabolism , Alveolar Epithelial Cells/pathology , Alveolar Epithelial Cells/virology , Angiotensin-Converting Enzyme 2/metabolism , COVID-19/pathology , COVID-19/virology , Cytokines/immunology , Cytokines/metabolism , Host-Pathogen Interactions/immunology , Humans , Immunity , Macrophages, Alveolar/immunology , Macrophages, Alveolar/metabolism , SARS-CoV-2/physiology
13.
Int J Mol Sci ; 22(14)2021 Jul 16.
Article in English | MEDLINE | ID: covidwho-1323266

ABSTRACT

Smoking is a major risk factor for chronic obstructive pulmonary disease (COPD) and causes remodeling of the small airways. However, the exact smoke-induced effects on the different types of small airway epithelial cells (SAECs) are poorly understood. Here, using air-liquid interface (ALI) cultures, single-cell RNA-sequencing reveals previously unrecognized transcriptional heterogeneity within the small airway epithelium and cell type-specific effects upon acute and chronic cigarette smoke exposure. Smoke triggers detoxification and inflammatory responses and aberrantly activates and alters basal cell differentiation. This results in an increase of inflammatory basal-to-secretory cell intermediates and, particularly after chronic smoke exposure, a massive expansion of a rare inflammatory and squamous metaplasia associated KRT6A+ basal cell state and an altered secretory cell landscape. ALI cultures originating from healthy non-smokers and COPD smokers show similar responses to cigarette smoke exposure, although an increased pro-inflammatory profile is conserved in the latter. Taken together, the in vitro models provide high-resolution insights into the smoke-induced remodeling of the small airways resembling the pathological processes in COPD airways. The data may also help to better understand other lung diseases including COVID-19, as the data reflect the smoke-dependent variable induction of SARS-CoV-2 entry factors across SAEC populations.


Subject(s)
Airway Remodeling/drug effects , Alveolar Epithelial Cells/drug effects , Cigarette Smoking/adverse effects , Epithelial Cells/metabolism , Alveolar Epithelial Cells/metabolism , Alveolar Epithelial Cells/pathology , Cell Differentiation/drug effects , Cells, Cultured , Cigarette Smoking/metabolism , Epithelial Cells/drug effects , Humans , Neoplasms, Basal Cell/metabolism , Primary Cell Culture , Pulmonary Disease, Chronic Obstructive/etiology , Pulmonary Disease, Chronic Obstructive/metabolism , Pulmonary Disease, Chronic Obstructive/pathology , Respiratory Mucosa/metabolism , Respiratory Mucosa/pathology , Smoke , Smoking/adverse effects , Smoking/metabolism
14.
Nat Commun ; 12(1): 4314, 2021 07 14.
Article in English | MEDLINE | ID: covidwho-1310804

ABSTRACT

Patients with chronic lung disease (CLD) have an increased risk for severe coronavirus disease-19 (COVID-19) and poor outcomes. Here, we analyze the transcriptomes of 611,398 single cells isolated from healthy and CLD lungs to identify molecular characteristics of lung cells that may account for worse COVID-19 outcomes in patients with chronic lung diseases. We observe a similar cellular distribution and relative expression of SARS-CoV-2 entry factors in control and CLD lungs. CLD AT2 cells express higher levels of genes linked directly to the efficiency of viral replication and the innate immune response. Additionally, we identify basal differences in inflammatory gene expression programs that highlight how CLD alters the inflammatory microenvironment encountered upon viral exposure to the peripheral lung. Our study indicates that CLD is accompanied by changes in cell-type-specific gene expression programs that prime the lung epithelium for and influence the innate and adaptive immune responses to SARS-CoV-2 infection.


Subject(s)
Lung Diseases/genetics , SARS-CoV-2/physiology , Transcriptome , Virus Internalization , Alveolar Epithelial Cells/metabolism , Alveolar Epithelial Cells/pathology , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , COVID-19/genetics , COVID-19/pathology , Chronic Disease , Humans , Idiopathic Pulmonary Fibrosis/genetics , Idiopathic Pulmonary Fibrosis/pathology , Immunity, Innate/genetics , Inflammation/genetics , Lung/metabolism , Lung/pathology , Lung Diseases/pathology , SARS-CoV-2/pathogenicity , Virus Replication/genetics
15.
Tissue Barriers ; 9(4): 1937013, 2021 10 02.
Article in English | MEDLINE | ID: covidwho-1298924

ABSTRACT

Blood-gas barrier (BGB) or alveolar-capillary barrier is the primary tissue barrier affected by coronavirus disease 2019 (COVID-19). Comprising alveolar epithelial cells (AECs), endothelial cells (ECs) and the extracellular matrix (ECM) in between, the BGB is damaged following the action of multiple pro-inflammatory cytokines during acute inflammation. The infection of AECs and ECs with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the pathogen behind COVID-19, triggers an inflammatory response at the BGB, inducing the release of interleukin 1 (IL-1), IL-6, tumor necrosis factor alpha (TNF-α), transforming growth factor beta (TGF-ß), high mobility group box 1 (HMGB1), matrix metalloproteinases (MMPs), intercellular adhesion molecule-1 (ICAM-1) and platelet activating factor (PAF). The end result is the disassembly of adherens junctions (AJs) and tight junctions (TJs) in both AECs and ECs, AEC hyperplasia, EC pyroptosis, ECM remodeling and deposition of fibrin clots in the alveolar capillaries, leading to disintegration and thickening of the BGB, and ultimately, hypoxia. This commentary seeks to provide a brief account of how the BGB might become affected in COVID-19.


Subject(s)
Blood-Air Barrier/metabolism , COVID-19/metabolism , Pulmonary Gas Exchange , Alveolar Epithelial Cells/metabolism , Alveolar Epithelial Cells/pathology , Blood-Air Barrier/pathology , COVID-19/pathology , Humans , Microvessels/metabolism , Microvessels/pathology
16.
Am J Respir Cell Mol Biol ; 64(6): 677-686, 2021 06.
Article in English | MEDLINE | ID: covidwho-1259048

ABSTRACT

There is an urgent need for new drugs for patients with acute respiratory distress syndrome (ARDS), including those with coronavirus disease (COVID-19). ARDS in influenza-infected mice is associated with reduced concentrations of liponucleotides (essential precursors for de novo phospholipid synthesis) in alveolar type II (ATII) epithelial cells. Because surfactant phospholipid synthesis is a primary function of ATII cells, we hypothesized that disrupting this process could contribute significantly to the pathogenesis of influenza-induced ARDS. The goal of this study was to determine whether parenteral liponucleotide supplementation can attenuate ARDS. C57BL/6 mice inoculated intranasally with 10,000 plaque-forming units/mouse of H1N1 influenza A/WSN/33 virus were treated with CDP (cytidine 5'-diphospho)-choline (100 µg/mouse i.p.) ± CDP -diacylglycerol 16:0/16:0 (10 µg/mouse i.p.) once daily from 1 to 5 days after inoculation (to model postexposure influenza prophylaxis) or as a single dose on Day 5 (to model treatment of patients with ongoing influenza-induced ARDS). Daily postexposure prophylaxis with CDP-choline attenuated influenza-induced hypoxemia, pulmonary edema, alterations in lung mechanics, impairment of alveolar fluid clearance, and pulmonary inflammation without altering viral replication. These effects were not recapitulated by the daily administration of CTP (cytidine triphosphate) and/or choline. Daily coadministration of CDP-diacylglycerol significantly enhanced the beneficial effects of CDP-choline and also modified the ATII cell lipidome, reversing the infection-induced decrease in phosphatidylcholine and increasing concentrations of most other lipid classes in ATII cells. Single-dose treatment with both liponucleotides at 5 days after inoculation also attenuated hypoxemia, altered lung mechanics, and inflammation. Overall, our data show that liponucleotides act rapidly to reduce disease severity in mice with severe influenza-induced ARDS.


Subject(s)
Alveolar Epithelial Cells/metabolism , Cytidine Diphosphate Choline/pharmacology , Cytidine Diphosphate Diglycerides/pharmacology , Influenza A Virus, H1N1 Subtype/metabolism , Orthomyxoviridae Infections/drug therapy , Respiratory Distress Syndrome/prevention & control , Alveolar Epithelial Cells/pathology , Alveolar Epithelial Cells/virology , Animals , COVID-19/drug therapy , COVID-19/pathology , Mice , Orthomyxoviridae Infections/complications , Orthomyxoviridae Infections/metabolism , Orthomyxoviridae Infections/pathology , Respiratory Distress Syndrome/etiology , Respiratory Distress Syndrome/metabolism , Respiratory Distress Syndrome/pathology , SARS-CoV-2/metabolism
17.
Nature ; 595(7865): 114-119, 2021 07.
Article in English | MEDLINE | ID: covidwho-1207147

ABSTRACT

Respiratory failure is the leading cause of death in patients with severe SARS-CoV-2 infection1,2, but the host response at the lung tissue level is poorly understood. Here we performed single-nucleus RNA sequencing of about 116,000 nuclei from the lungs of nineteen individuals who died of COVID-19 and underwent rapid autopsy and seven control individuals. Integrated analyses identified substantial alterations in cellular composition, transcriptional cell states, and cell-to-cell interactions, thereby providing insight into the biology of lethal COVID-19. The lungs from individuals with COVID-19 were highly inflamed, with dense infiltration of aberrantly activated monocyte-derived macrophages and alveolar macrophages, but had impaired T cell responses. Monocyte/macrophage-derived interleukin-1ß and epithelial cell-derived interleukin-6 were unique features of SARS-CoV-2 infection compared to other viral and bacterial causes of pneumonia. Alveolar type 2 cells adopted an inflammation-associated transient progenitor cell state and failed to undergo full transition into alveolar type 1 cells, resulting in impaired lung regeneration. Furthermore, we identified expansion of recently described CTHRC1+ pathological fibroblasts3 contributing to rapidly ensuing pulmonary fibrosis in COVID-19. Inference of protein activity and ligand-receptor interactions identified putative drug targets to disrupt deleterious circuits. This atlas enables the dissection of lethal COVID-19, may inform our understanding of long-term complications of COVID-19 survivors, and provides an important resource for therapeutic development.


Subject(s)
COVID-19/pathology , COVID-19/virology , Lung/pathology , SARS-CoV-2/pathogenicity , Single-Cell Analysis , Aged , Aged, 80 and over , Alveolar Epithelial Cells/pathology , Alveolar Epithelial Cells/virology , Atlases as Topic , Autopsy , COVID-19/immunology , Case-Control Studies , Female , Fibroblasts/pathology , Fibrosis/pathology , Fibrosis/virology , Humans , Inflammation/pathology , Inflammation/virology , Macrophages/pathology , Macrophages/virology , Macrophages, Alveolar/pathology , Macrophages, Alveolar/virology , Male , Middle Aged , Plasma Cells/immunology , T-Lymphocytes/immunology
18.
Nature ; 594(7861): 88-93, 2021 06.
Article in English | MEDLINE | ID: covidwho-1171428

ABSTRACT

COVID-19 is a disease with unique characteristics that include lung thrombosis1, frequent diarrhoea2, abnormal activation of the inflammatory response3 and rapid deterioration of lung function consistent with alveolar oedema4. The pathological substrate for these findings remains unknown. Here we show that the lungs of patients with COVID-19 contain infected pneumocytes with abnormal morphology and frequent multinucleation. The generation of these syncytia results from activation of the SARS-CoV-2 spike protein at the cell plasma membrane level. On the basis of these observations, we performed two high-content microscopy-based screenings with more than 3,000 approved drugs to search for inhibitors of spike-driven syncytia. We converged on the identification of 83 drugs that inhibited spike-mediated cell fusion, several of which belonged to defined pharmacological classes. We focused our attention on effective drugs that also protected against virus replication and associated cytopathicity. One of the most effective molecules was the antihelminthic drug niclosamide, which markedly blunted calcium oscillations and membrane conductance in spike-expressing cells by suppressing the activity of TMEM16F (also known as anoctamin 6), a calcium-activated ion channel and scramblase that is responsible for exposure of phosphatidylserine on the cell surface. These findings suggest a potential mechanism for COVID-19 disease pathogenesis and support the repurposing of niclosamide for therapy.


Subject(s)
Anoctamins/antagonists & inhibitors , COVID-19/pathology , Cell Fusion , Drug Evaluation, Preclinical , Giant Cells/drug effects , SARS-CoV-2/drug effects , Spike Glycoprotein, Coronavirus/antagonists & inhibitors , Aged , Aged, 80 and over , Alveolar Epithelial Cells/drug effects , Alveolar Epithelial Cells/pathology , Alveolar Epithelial Cells/virology , Animals , Anoctamins/metabolism , COVID-19/metabolism , COVID-19/virology , Calcium Signaling/drug effects , Cell Line , Chloride Channels/metabolism , Chlorocebus aethiops , Female , Giant Cells/metabolism , Giant Cells/virology , Humans , Lung/drug effects , Lung/pathology , Lung/virology , Male , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/metabolism , Virus Replication/drug effects
19.
Med Sci Monit ; 27: e928837, 2021 Feb 13.
Article in English | MEDLINE | ID: covidwho-1161104

ABSTRACT

BACKGROUND Coronavirus 2 (SARS-CoV-2) was declared a pandemic by the World Health Organization (WHO) in March 2020. To further reveal the pathologic associations between coronavirus and hypoxemia, we report the findings of 4 complete systematic autopsies of severe acute respiratory syndrome coronavirus 2-positive individuals who died of multiple organ failure caused by severe hypoxemia. MATERIAL AND METHODS We examined the donated corpses of 4 deceased patients who had been diagnosed with severe acute respiratory syndrome coronavirus 2. A complete post-mortem examination was carried out on each corpse, and multiple organs were macroscopically examined. RESULTS The 4 corpses were 2 males and 2 females, with an average age of 69 years. Bilateral lungs showed various degrees of atrophy and consolidation, with diffusely tough and solid texture in the sections. A thromboembolism was found in the main pulmonary artery extending into the atrium in 1 corpse, and significant atherosclerotic plaques tagged in the inner wall of the aortic arch were found in 2 corpses. Two corpses were found to have slightly atrophied bilateral renal parenchyma. Atrophic changes in the spleen were found in 2 corpses. Notably, there were significantly expanded alveolar septa and prominent fibroblastic proliferation. CONCLUSIONS The laboratory data of these corpses showed a progressive decrease in blood oxygen saturation, followed by refractory and irreversible hypoxemia. Clinical and laboratory information and autopsy and histologic presentations of multiple organs showed insufficient air exchange due to abnormalities in the respiratory system, and reduced erythropoiesis in bone marrow may play a role.


Subject(s)
Autopsy , COVID-19/pathology , COVID-19/virology , Hypoxia/complications , Hypoxia/pathology , Pneumonia/pathology , Pneumonia/virology , SARS-CoV-2/physiology , Aged , Aged, 80 and over , Alveolar Epithelial Cells/metabolism , Alveolar Epithelial Cells/pathology , COVID-19/complications , Cell Aggregation , Female , Humans , Lung/pathology , Macrophages/pathology , Male , Middle Aged , Mucus/metabolism , Myocardium/pathology , Necrosis , Pneumonia/complications , Thoracic Cavity/pathology
20.
Nature ; 593(7860): 564-569, 2021 05.
Article in English | MEDLINE | ID: covidwho-1155701

ABSTRACT

Recent studies have provided insights into the pathology of and immune response to COVID-191-8. However, a thorough investigation of the interplay between infected cells and the immune system at sites of infection has been lacking. Here we use high-parameter imaging mass cytometry9 that targets the expression of 36 proteins to investigate the cellular composition and spatial architecture of acute lung injury in humans (including injuries derived from SARS-CoV-2 infection) at single-cell resolution. These spatially resolved single-cell data unravel the disordered structure of the infected and injured lung, alongside the distribution of extensive immune infiltration. Neutrophil and macrophage infiltration are hallmarks of bacterial pneumonia and COVID-19, respectively. We provide evidence that SARS-CoV-2 infects predominantly alveolar epithelial cells and induces a localized hyperinflammatory cell state that is associated with lung damage. We leverage the temporal range of fatal outcomes of COVID-19 in relation to the onset of symptoms, which reveals increased macrophage extravasation and increased numbers of mesenchymal cells and fibroblasts concomitant with increased proximity between these cell types as the disease progresses-possibly as a result of attempts to repair the damaged lung tissue. Our data enable us to develop a biologically interpretable landscape of lung pathology from a structural, immunological and clinical standpoint. We use this landscape to characterize the pathophysiology of the human lung from its macroscopic presentation to the single-cell level, which provides an important basis for understanding COVID-19 and lung pathology in general.


Subject(s)
COVID-19/pathology , COVID-19/virology , Disease Progression , Lung/pathology , Lung/virology , SARS-CoV-2/pathogenicity , Single-Cell Analysis , Alveolar Epithelial Cells/pathology , Alveolar Epithelial Cells/virology , COVID-19/mortality , COVID-19/physiopathology , Humans , Inflammation/pathology , Inflammation/physiopathology , Inflammation/virology , Lung/physiopathology , Macrophages/immunology , Neutrophils/immunology , Time Factors , Viral Tropism
SELECTION OF CITATIONS
SEARCH DETAIL