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1.
Sci Rep ; 12(1): 4058, 2022 03 08.
Article in English | MEDLINE | ID: covidwho-1735282

ABSTRACT

Angiotensin-converting enzyme 2 (ACE2) is a key host protein by which severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) enters and multiplies within cells. The level of ACE2 expression in the lung is hypothesised to correlate with an increased risk of severe infection and complications in COrona VIrus Disease 2019 (COVID-19). To test this hypothesis, we compared the protein expression status of ACE2 by immunohistochemistry (IHC) in post-mortem lung samples of patients who died of severe COVID-19 and lung samples obtained from non-COVID-19 patients for other indications. IHC for CD61 and CD163 was performed for the assessment of platelet-rich microthrombi and macrophages, respectively. IHC for SARS-CoV-2 viral antigen was also performed. In a total of 55, 44 COVID-19 post-mortem lung samples were tested for ACE2, 36 for CD163, and 26 for CD61, compared to 15 non-covid 19 control lung sections. Quantification of immunostaining, random sampling, and correlation analysis were used to substantiate the morphologic findings. Our results show that ACE2 protein expression was significantly higher in COVID-19 post-mortem lung tissues than in controls, regardless of sample size. Histomorphology in COVID-19 lungs showed diffuse alveolar damage (DAD), acute bronchopneumonia, and acute lung injury with SARS-CoV-2 viral protein detected in a subset of cases. ACE2 expression levels were positively correlated with increased expression levels of CD61 and CD163. In conclusion, our results show significantly higher ACE2 protein expression in severe COVID-19 disease, correlating with increased macrophage infiltration and microthrombi, suggesting a pathobiological role in disease severity.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , COVID-19/pathology , Lung/metabolism , Acute Lung Injury/pathology , Adolescent , Adult , Aged , Aged, 80 and over , Angiotensin-Converting Enzyme 2/genetics , Antigens, CD/genetics , Antigens, CD/metabolism , Antigens, Differentiation, Myelomonocytic/genetics , Antigens, Differentiation, Myelomonocytic/metabolism , Autopsy , COVID-19/virology , Case-Control Studies , Female , Humans , Immunohistochemistry , Integrin beta3/genetics , Integrin beta3/metabolism , Lung/pathology , Male , Middle Aged , Receptors, Cell Surface/genetics , Receptors, Cell Surface/metabolism , SARS-CoV-2/isolation & purification , Severity of Illness Index , Young Adult
2.
Chem Commun (Camb) ; 58(13): 2120-2123, 2022 Feb 10.
Article in English | MEDLINE | ID: covidwho-1639577

ABSTRACT

The coronavirus 2019 (COVID-19) pandemic is causing serious impacts in the world, and safe and effective vaccines and medicines are the best methods to combat the disease. The receptor-binding domain (RBD) of the SARS-CoV-2 spike protein plays a key role in interacting with the angiotensin-converting enzyme 2 (ACE2) receptor, and is regarded as an important target of vaccines. Herein, we constructed the adjuvant-protein conjugate Pam3CSK4-RBD as a vaccine candidate, in which the N-terminal of the RBD was site-selectively oxidized by transamination and conjugated with the TLR1/2 agonist Pam3CSK4. This demonstrated that the conjugation of Pam3CSK4 significantly enhanced the anti-RBD antibody response and cellular response. In addition, sera from the Pam3CSK4-RBD immunized group efficiently inhibited the binding of the RBD to ACE2 and protected cells from SARS-CoV-2 and four variants of concern (alpha, beta, gamma and delta), indicating that this adjuvant strategy could be one of the effective means for protein vaccine development.


Subject(s)
COVID-19/prevention & control , Lipopeptides/chemistry , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/chemistry , Vaccines, Conjugate/immunology , Angiotensin-Converting Enzyme 2/metabolism , Animals , Antibody Formation , Antigens, CD/metabolism , Antigens, Differentiation, Myelomonocytic/metabolism , COVID-19/virology , Female , HEK293 Cells , Humans , Macrophages/cytology , Macrophages/immunology , Macrophages/metabolism , Mice , Mice, Inbred BALB C , Protein Binding , Protein Domains/immunology , RAW 264.7 Cells , Recombinant Proteins/biosynthesis , Recombinant Proteins/immunology , SARS-CoV-2/isolation & purification , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/metabolism , Vaccines, Conjugate/administration & dosage , Vaccines, Conjugate/chemistry
3.
Cell ; 184(26): 6243-6261.e27, 2021 12 22.
Article in English | MEDLINE | ID: covidwho-1536467

ABSTRACT

COVID-19-induced "acute respiratory distress syndrome" (ARDS) is associated with prolonged respiratory failure and high mortality, but the mechanistic basis of lung injury remains incompletely understood. Here, we analyze pulmonary immune responses and lung pathology in two cohorts of patients with COVID-19 ARDS using functional single-cell genomics, immunohistology, and electron microscopy. We describe an accumulation of CD163-expressing monocyte-derived macrophages that acquired a profibrotic transcriptional phenotype during COVID-19 ARDS. Gene set enrichment and computational data integration revealed a significant similarity between COVID-19-associated macrophages and profibrotic macrophage populations identified in idiopathic pulmonary fibrosis. COVID-19 ARDS was associated with clinical, radiographic, histopathological, and ultrastructural hallmarks of pulmonary fibrosis. Exposure of human monocytes to SARS-CoV-2, but not influenza A virus or viral RNA analogs, was sufficient to induce a similar profibrotic phenotype in vitro. In conclusion, we demonstrate that SARS-CoV-2 triggers profibrotic macrophage responses and pronounced fibroproliferative ARDS.


Subject(s)
COVID-19/pathology , COVID-19/virology , Idiopathic Pulmonary Fibrosis/pathology , Idiopathic Pulmonary Fibrosis/virology , Macrophages/pathology , Macrophages/virology , SARS-CoV-2/physiology , Antigens, CD/metabolism , Antigens, Differentiation, Myelomonocytic/metabolism , COVID-19/diagnostic imaging , Cell Communication , Cohort Studies , Fibroblasts/pathology , Gene Expression Regulation , Humans , Idiopathic Pulmonary Fibrosis/diagnostic imaging , Idiopathic Pulmonary Fibrosis/genetics , Mesenchymal Stem Cells/pathology , Phenotype , Proteome/metabolism , Receptors, Cell Surface/metabolism , Respiratory Distress Syndrome/diagnostic imaging , Respiratory Distress Syndrome/pathology , Respiratory Distress Syndrome/virology , Tomography, X-Ray Computed , Transcription, Genetic
4.
Front Immunol ; 12: 676828, 2021.
Article in English | MEDLINE | ID: covidwho-1320577

ABSTRACT

In coronavirus disease 2019 (COVID-19), ulcerative lesions have been episodically reported in various segments of the gastrointestinal (GI) tract, including the oral cavity, oropharynx, esophagus, stomach and bowel. In this report, we describe an autopsy case of a COVID-19 patient who showed two undiagnosed ulcers at the level of the anterior and posterior walls of the hypopharynx. Molecular testing of viruses involved in pharyngeal ulcers demonstrated the presence of severe acute respiratory syndrome - coronavirus type 2 (SARS-CoV-2) RNA, together with herpes simplex virus 1 DNA. Histopathologic analysis demonstrated full-thickness lympho-monocytic infiltration (mainly composed of CD68-positive cells), with hemorrhagic foci and necrosis of both the mucosal layer and deep skeletal muscle fibers. Fibrin and platelet microthrombi were also found. Cytological signs of HSV-1 induced damage were not found. Cells expressing SARS-CoV-2 spike subunit 1 were immunohistochemically identified in the inflammatory infiltrations. Immunohistochemistry for HSV1 showed general negativity for inflammatory infiltration, although in the presence of some positive cells. Thus, histopathological, immunohistochemical and molecular findings supported a direct role by SARS-CoV-2 in producing local ulcerative damage, although a possible contributory role by HSV-1 reactivation cannot be excluded. From a clinical perspective, this autopsy report of two undiagnosed lesions put the question if ulcers along the GI tract could be more common (but frequently neglected) in COVID-19 patients.


Subject(s)
COVID-19/complications , Hypopharynx/pathology , SARS-CoV-2/isolation & purification , Ulcer/pathology , Aged , Antigens, CD/metabolism , Antigens, Differentiation, Myelomonocytic/metabolism , Autopsy , Blood Platelets/metabolism , Blood Platelets/pathology , COVID-19/mortality , COVID-19/pathology , COVID-19/physiopathology , Gastrointestinal Tract/pathology , Herpesvirus 1, Human/genetics , Herpesvirus 1, Human/isolation & purification , Humans , Hypopharynx/virology , Immunohistochemistry , Inflammation/immunology , Inflammation/metabolism , Inflammation/virology , Lymphocytes/metabolism , Monocytes/metabolism , Mucous Membrane/pathology , Muscle, Skeletal/pathology , Necrosis/pathology , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/metabolism , Thrombosis/pathology , Ulcer/virology
5.
Int J Mol Sci ; 22(6)2021 Mar 15.
Article in English | MEDLINE | ID: covidwho-1136499

ABSTRACT

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in significant morbidity and mortality across the world, with no current effective treatments available. Recent studies suggest the possibility of a cytokine storm associated with severe COVID-19, similar to the biochemical profile seen in hemophagocytic lymphohistiocytosis (HLH), raising the question of possible benefits that could be derived from targeted immunosuppression in severe COVID-19 patients. We reviewed the literature regarding the diagnosis and features of HLH, particularly secondary HLH, and aimed to identify gaps in the literature to truly clarify the existence of a COVID-19 associated HLH. Diagnostic criteria such as HScore or HLH-2004 may have suboptimal performance in identifying COVID-19 HLH-like presentations, and criteria such as soluble CD163, NK cell activity, or other novel biomarkers may be more useful in identifying this entity.


Subject(s)
COVID-19/complications , COVID-19/diagnosis , Lymphohistiocytosis, Hemophagocytic/diagnosis , Lymphohistiocytosis, Hemophagocytic/etiology , Antigens, CD/metabolism , Antigens, Differentiation, Myelomonocytic/metabolism , Humans , Killer Cells, Natural/metabolism , Receptors, Cell Surface/metabolism , Receptors, Interleukin-2/metabolism , Sepsis/etiology
6.
JAMA Cardiol ; 5(10): 1170-1175, 2020 10 01.
Article in English | MEDLINE | ID: covidwho-636079

ABSTRACT

Importance: Cytokine release syndrome is a complication of coronavirus disease 2019. Clinically, advanced age and cardiovascular comorbidities are the most important risk factors. Objective: To determine whether clonal hematopoiesis of indeterminate potential (CHIP), an age-associated condition with excess cardiovascular risk defined as the presence of an expanded, mutated somatic blood cell clone in persons without other hematological abnormalities, may be associated with an inflammatory gene expression sensitizing monocytes to aggravated immune responses. Design, Setting, and Participants: This hypothesis-generating diagnostic study examined a cohort of patients with severe degenerative aortic valve stenosis or chronic postinfarction heart failure, as well as age-matched healthy control participants. Single-cell RNA sequencing and analyses of circulating peripheral monocytes was done between 2017 and 2019 to assess the transcriptome of circulating monocytes. Exposures: Severe degenerative aortic valve stenosis or chronic postinfarction heart failure. Main Outcomes and Measures: CHIP-driver sequence variations in monocytes with a proinflammatory signature of genes involved in cytokine release syndrome. Results: The study included 8 patients with severe degenerative aortic valve stenosis, 6 with chronic postinfarction heart failure, and 3 healthy control participants. Their mean age was 75.7 (range, 54-89) years, and 6 were women. Mean CHIP-driver gene variant allele frequency was 4.2% (range, 2.5%-6.9%) for DNMT3A and 14.3% (range, 2.6%-37.4%) for TET2. Participants with DNMT3A or TET2 CHIP-driver sequence variations displayed increased expression of interleukin 1ß (no CHIP-driver sequence variations, 1.6217 normalized Unique Molecular Identifiers [nUMI]; DNMT3A, 5.3956 nUMI; P < .001; TET2, 10.8216 nUMI; P < .001), the interleukin 6 receptor (no CHIP-driver sequence variations, 0.5386 nUMI; DNMT3A, 0.9162 nUMI; P < .001;TET2, 0.5738 nUMI; P < .001), as well as the NLRP3 inflammasome complex (no CHIP-driver sequence variations, 0.4797 nUMI; DNMT3A, 0.9961 nUMI; P < .001; TET2, 1.2189 nUMI; P < .001), plus upregulation of CD163 (no CHIP-driver sequence variations, 0.5239 nUMI; DNMT3A, 1.4722 nUMI; P < .001; TET2, 1.0684 nUMI; P < .001), a cellular receptor capable of mediating infection, macrophage activation syndrome, and other genes involved in cytokine response syndrome. Gene ontology term analyses of regulated genes revealed that the most significantly upregulated genes encode for leukocyte-activation and interleukin-signaling pathways in monocytes of individuals with DNMT3A (myeloid leukocyte activation: log[Q value], -50.1986; log P value, -54.5177; regulation of cytokine production: log[Q value], -21.0264; log P value, -24.1993; signaling by interleukins: log[Q value], -18.0710: log P value, -21.1597) or TET2 CHIP-driver sequence variations (immune response: log[Q value], -36.3673; log P value, -40.6864; regulation of cytokine production: log[Q value], -13.1733; log P value, -16.3463; signaling by interleukins: log[Q value], -12.6547: log P value, -15.7977). Conclusions and Relevance: Monocytes of individuals who carry CHIP-driver sequence variations and have cardiovascular disease appear to be primed for excessive inflammatory responses. Further studies are warranted to address potential adverse outcomes of coronavirus disease 2019 in patients with CHIP-driver sequence variations.


Subject(s)
Aortic Valve Stenosis/complications , Clonal Hematopoiesis/genetics , Gene Expression , Heart Failure/complications , Aged , Aged, 80 and over , Antigens, CD/metabolism , Antigens, Differentiation, Myelomonocytic/metabolism , COVID-19/complications , Case-Control Studies , Cytokine Release Syndrome/genetics , Cytokines/metabolism , DNA (Cytosine-5-)-Methyltransferases/genetics , DNA-Binding Proteins/genetics , Dioxygenases , Female , Genetic Predisposition to Disease , Genetic Variation , Heterozygote , Humans , Male , Middle Aged , Monocytes , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Proto-Oncogene Proteins/genetics , Receptors, Cell Surface/metabolism , Receptors, Interleukin-6/metabolism , Transcriptome
7.
Med Hypotheses ; 144: 110168, 2020 Nov.
Article in English | MEDLINE | ID: covidwho-696328

ABSTRACT

SARS-CoV-2 interaction with the ACE-2 receptor cannot alone explain the demography and remarkable variation in clinical progression of Covid-19 infection. Unlike SARS-CoV, the cause of SARS, several SARS-CoV-2 spike glycans contain sialic acid residues. In contrast to the SARS secreted glycoprotein (SGP), SARS-CoV-2 SGP are thus potential ligands for Sialic acid-binding Siglecs on host immune cells, known to regulate immune function. Such SARS-CoV-2 glycoproteins would contribute to immune deviation. CD33-related Siglecs are important immune regulators. Siglec-5 and -14 are paired receptors with opposed actions on the NLRP3 inflammasome, which is critical in early viral clearance. SGP binding in persons of Siglec-14 null genotype (30-70% in Black, Asian and Minority Ethnic (BAME) persons, 10% in North Europeans) would induce unopposed inhibitory signalling, causing viral persistence through inflammasome inhibition. Siglec-3 (CD33) and Siglec-5 are expressed on CD33 myeloid derived suppressor cells (CD33 MDSC). Immunosuppressive CD33 MDSC populations are increased in all groups at risk of severe Covid-19 infection. CD33 expression is increased in persons with the CD33 rs3865444 CC allele, associated with Alzheimer's disease, who would thus show enhanced susceptibility. Viral SGP ligation of CD33, potentially in conjunction with Siglec-5, would promote expansion of CD33 MDSC cells, as occurs in cancers but at much greater scale. CD33 is expressed on CNS microglia, potentially activated by SGP penetration through the porous cribriform plate to cause anosmia. Genotyping of severe or fatal Covid-19 cases can confirm or refute this pathophysiological mechanism. Early data have confirmed extremely high-level increase of CD33 MDSC numbers in severe Covid-19 infection, consistent with the proposed mechanism.


Subject(s)
Antigens, CD/metabolism , Antigens, Differentiation, Myelomonocytic/metabolism , COVID-19/metabolism , COVID-19/virology , Lectins/metabolism , Sialic Acid Binding Ig-like Lectin 3/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Alleles , Antiviral Agents/therapeutic use , COVID-19/immunology , Child , Disease Progression , Female , Genotype , Humans , Immunity, Innate , Inflammasomes , Inflammation , Ligands , Male , Models, Theoretical , Mutation , Polymorphism, Genetic , Polysaccharides/chemistry , Protein Binding , SARS-CoV-2 , Sex Factors , Systemic Inflammatory Response Syndrome/immunology
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