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1.
Int Immunopharmacol ; 108: 108697, 2022 Jul.
Article in English | MEDLINE | ID: covidwho-1739816

ABSTRACT

Monocytes play a major role in the initial innate immune response to SARS-CoV-2. Although viral load may correlate with several clinical outcomes in COVID-19, much less is known regarding their impact on innate immune phenotype. We evaluated the monocyte phenotype and mitochondrial function in severe COVID-19 patients (n = 22) with different viral burden (determined by the median of viral load of the patients) at hospital admission. Severe COVID-19 patients presented lower frequency of CD14 + CD16- classical monocytes and CD39 expression on CD14 + monocytes, and higher frequency of CD14 + CD16 + intermediate and CD14-CD16 + nonclassical monocytes as compared to healthy controls independently of viral load. COVID-19 patients with high viral load exhibited increased GM-CSF, PGE-2 and lower IFN-α as compared to severe COVID-19 patients with low viral load (p < 0.05). CD14 + monocytes of COVID-19 patients with high viral load presented higher expression of PD-1 but lower HLA-DR on the cell surface than severe COVID-19 patients with low viral load. All COVID-19 patients presented decreased monocyte mitochondria membrane polarization, but high SARS-CoV-2 viral load was associated with increased mitochondrial reactive oxygen species. In this sense, higher viral load induces mitochondrial reactive oxygen species generation associated with exhaustion profile in CD14 + monocytes of severe COVID-19 patients. Altogether, these data shed light on new pathological mechanisms involving SARS-CoV-2 viral load on monocyte activation and mitochondrial function, which were associated with COVID-19 severity.


Subject(s)
COVID-19 , Monocytes , Biomarkers/metabolism , Humans , Lipopolysaccharide Receptors/metabolism , Mitochondria/metabolism , Phenotype , Reactive Oxygen Species/metabolism , Receptors, IgG/metabolism , SARS-CoV-2 , Viral Load
2.
Front Immunol ; 12: 799558, 2021.
Article in English | MEDLINE | ID: covidwho-1662582

ABSTRACT

The poor outcome of the coronavirus disease-2019 (COVID-19), caused by SARS-CoV-2, is associated with systemic hyperinflammatory response and immunopathology. Although inflammasome and oxidative stress have independently been implicated in COVID-19, it is poorly understood whether these two pathways cooperatively contribute to disease severity. Herein, we found an enrichment of CD14highCD16- monocytes displaying inflammasome activation evidenced by caspase-1/ASC-speck formation in severe COVID-19 patients when compared to mild ones and healthy controls, respectively. Those cells also showed aberrant levels of mitochondrial superoxide and lipid peroxidation, both hallmarks of the oxidative stress response, which strongly correlated with caspase-1 activity. In addition, we found that NLRP3 inflammasome-derived IL-1ß secretion by SARS-CoV-2-exposed monocytes in vitro was partially dependent on lipid peroxidation. Importantly, altered inflammasome and stress responses persisted after short-term patient recovery. Collectively, our findings suggest oxidative stress/NLRP3 signaling pathway as a potential target for host-directed therapy to mitigate early COVID-19 hyperinflammation and also its long-term outcomes.


Subject(s)
COVID-19/metabolism , Inflammasomes/metabolism , Lipopolysaccharide Receptors/metabolism , Monocytes/metabolism , Oxidative Stress/physiology , Receptors, IgG/metabolism , Aged , COVID-19/pathology , Caspase 1/metabolism , Female , GPI-Linked Proteins/metabolism , Humans , Interleukin-1beta/metabolism , Male , Middle Aged , Mitochondria/metabolism , Mitochondria/pathology , Monocytes/pathology , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , SARS-CoV-2/metabolism , Signal Transduction/physiology
3.
Front Immunol ; 12: 807134, 2021.
Article in English | MEDLINE | ID: covidwho-1604257

ABSTRACT

ORF8 is a viral immunoglobulin-like (Ig-like) domain protein encoded by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA genome. It tends to evolve rapidly and interfere with immune responses. However, the structural characteristics of various coronavirus ORF8 proteins and their subsequent effects on biological functions remain unclear. Herein, we determined the crystal structures of SARS-CoV-2 ORF8 (S84) (one of the epidemic isoforms) and the bat coronavirus RaTG13 ORF8 variant at 1.62 Å and 1.76 Å resolution, respectively. Comparison of these ORF8 proteins demonstrates that the 62-77 residues in Ig-like domain of coronavirus ORF8 adopt different conformations. Combined with mutagenesis assays, the residue Cys20 of ORF8 is responsible for forming the covalent disulfide-linked dimer in crystal packing and in vitro biochemical conditions. Furthermore, immune cell-binding assays indicate that various ORF8 (SARS-CoV-2 ORF8 (L84), ORF8 (S84), and RaTG13 ORF8) proteins have different interaction capabilities with human CD14+ monocytes in human peripheral blood. These results provide new insights into the specific characteristics of various coronavirus ORF8 and suggest that ORF8 variants may influence disease-related immune responses.


Subject(s)
COVID-19/immunology , Chiroptera/immunology , Immunity/immunology , Immunoglobulin Domains/immunology , Viral Proteins/immunology , Animals , Binding Sites/genetics , COVID-19/virology , Cells, Cultured , Chiroptera/genetics , Chiroptera/metabolism , Crystallography, X-Ray , Humans , Immunity/genetics , Immunoglobulin Domains/genetics , Lipopolysaccharide Receptors/immunology , Lipopolysaccharide Receptors/metabolism , Models, Molecular , Monocytes/immunology , Monocytes/metabolism , Mutation , Protein Binding , Species Specificity , Viral Proteins/classification , Viral Proteins/genetics
5.
Front Immunol ; 12: 697840, 2021.
Article in English | MEDLINE | ID: covidwho-1359188

ABSTRACT

Monocytes are antigen-presenting cells (APCs) that play diverse roles in promoting or regulating inflammatory responses, but their role in T cell stimulation is not well defined. In inflammatory conditions, monocytes frequently show increased expression of CD169/Siglec-1, a type-I interferon (IFN-I)-regulated protein. However, little is known about the phenotype and function of these CD169+ monocytes. Here, we have investigated the phenotype of human CD169+ monocytes in different diseases, their capacity to activate CD8+ T cells, and the potential for a targeted-vaccination approach. Using spectral flow cytometry, we detected CD169 expression by CD14+ CD16- classical and CD14+ CD16+ intermediate monocytes and unbiased analysis showed that they were distinct from dendritic cells, including the recently described CD14-expressing DC3. CD169+ monocytes expressed higher levels of co-stimulatory and HLA molecules, suggesting an increased activation state. IFNα treatment highly upregulated CD169 expression on CD14+ monocytes and boosted their capacity to cross-present antigen to CD8+ T cells. Furthermore, we observed CD169+ monocytes in virally-infected patients, including in the blood and bronchoalveolar lavage fluid of COVID-19 patients, as well as in the blood of patients with different types of cancers. Finally, we evaluated two CD169-targeting nanovaccine platforms, antibody-based and liposome-based, and we showed that CD169+ monocytes efficiently presented tumor-associated peptides gp100 and WT1 to antigen-specific CD8+ T cells. In conclusion, our data indicate that CD169+ monocytes are activated monocytes with enhanced CD8+ T cell stimulatory capacity and that they emerge as an interesting target in nanovaccine strategies, because of their presence in health and different diseases.


Subject(s)
Antigen Presentation/immunology , CD8-Positive T-Lymphocytes/immunology , Lymphocyte Activation/immunology , Monocytes/immunology , Sialic Acid Binding Ig-like Lectin 1/metabolism , COVID-19/immunology , Carcinoma, Pancreatic Ductal/immunology , Cells, Cultured , Flow Cytometry , Humans , Influenza, Human/immunology , Interferon-alpha/pharmacology , Lipopolysaccharide Receptors/metabolism , Lung Neoplasms/immunology , Pancreatic Neoplasms/immunology , SARS-CoV-2/immunology
6.
JCI Insight ; 6(13)2021 06 18.
Article in English | MEDLINE | ID: covidwho-1346128

ABSTRACT

We explored the potential link between chronic inflammatory arthritis and COVID-19 pathogenic and resolving macrophage pathways and their role in COVID-19 pathogenesis. We found that bronchoalveolar lavage fluid (BALF) macrophage clusters FCN1+ and FCN1+SPP1+ predominant in severe COVID-19 were transcriptionally related to synovial tissue macrophage (STM) clusters CD48hiS100A12+ and CD48+SPP1+ that drive rheumatoid arthritis (RA) synovitis. BALF macrophage cluster FABP4+ predominant in healthy lung was transcriptionally related to STM cluster TREM2+ that governs resolution of synovitis in RA remission. Plasma concentrations of SPP1 and S100A12 (key products of macrophage clusters shared with active RA) were high in severe COVID-19 and predicted the need for Intensive Care Unit transfer, and they remained high in the post-COVID-19 stage. High plasma levels of SPP1 were unique to severe COVID-19 when compared with other causes of severe pneumonia, and IHC localized SPP1+ macrophages in the alveoli of COVID-19 lung. Investigation into SPP1 mechanisms of action revealed that it drives proinflammatory activation of CD14+ monocytes and development of PD-L1+ neutrophils, both hallmarks of severe COVID-19. In summary, COVID-19 pneumonitis appears driven by similar pathogenic myeloid cell pathways as those in RA, and their mediators such as SPP1 might be an upstream activator of the aberrant innate response in severe COVID-19 and predictive of disease trajectory including post-COVID-19 pathology.


Subject(s)
Arthritis, Rheumatoid/immunology , COVID-19/immunology , Monocytes/immunology , Neutrophils/immunology , Osteopontin/immunology , Arthritis, Rheumatoid/metabolism , B7-H1 Antigen/immunology , Bronchoalveolar Lavage Fluid/immunology , CD48 Antigen/immunology , COVID-19/chemically induced , COVID-19/metabolism , Fatty Acid-Binding Proteins/immunology , Humans , Lectins/immunology , Lipopolysaccharide Receptors/immunology , Lipopolysaccharide Receptors/metabolism , Lung/diagnostic imaging , Lung/immunology , Lung/metabolism , Lung/pathology , Macrophages/immunology , Macrophages/metabolism , Membrane Glycoproteins/immunology , Monocytes/metabolism , Neutrophils/metabolism , Osteopontin/blood , Receptor Protein-Tyrosine Kinases/metabolism , Receptors, Immunologic/immunology , S100A12 Protein/immunology , S100A12 Protein/metabolism , Synovial Membrane/immunology , Tomography, X-Ray Computed
7.
Cell Rep Med ; 2(6): 100291, 2021 06 15.
Article in English | MEDLINE | ID: covidwho-1307253

ABSTRACT

Acute respiratory distress syndrome (ARDS) is the main complication of coronavirus disease 2019 (COVID-19), requiring admission to the intensive care unit (ICU). Despite extensive immune profiling of COVID-19 patients, to what extent COVID-19-associated ARDS differs from other causes of ARDS remains unknown. To address this question, here, we build 3 cohorts of patients categorized in COVID-19-ARDS+, COVID-19+ARDS+, and COVID-19+ARDS-, and compare, by high-dimensional mass cytometry, their immune landscape. A cell signature associating S100A9/calprotectin-producing CD169+ monocytes, plasmablasts, and Th1 cells is found in COVID-19+ARDS+, unlike COVID-19-ARDS+ patients. Moreover, this signature is essentially shared with COVID-19+ARDS- patients, suggesting that severe COVID-19 patients, whether or not they experience ARDS, display similar immune profiles. We show an increase in CD14+HLA-DRlow and CD14lowCD16+ monocytes correlating to the occurrence of adverse events during the ICU stay. We demonstrate that COVID-19-associated ARDS displays a specific immune profile and may benefit from personalized therapy in addition to standard ARDS management.


Subject(s)
COVID-19/pathology , Leukocytes, Mononuclear/metabolism , Respiratory Distress Syndrome/immunology , Aged , COVID-19/complications , COVID-19/virology , Cohort Studies , Evolution, Molecular , Female , HLA-DR Antigens/metabolism , Humans , Intensive Care Units , Leukocytes, Mononuclear/cytology , Leukocytes, Mononuclear/immunology , Lipopolysaccharide Receptors/metabolism , Machine Learning , Male , Middle Aged , Monocytes/cytology , Monocytes/immunology , Monocytes/metabolism , Respiratory Distress Syndrome/etiology , Respiratory Distress Syndrome/pathology , SARS-CoV-2/isolation & purification , Sialic Acid Binding Ig-like Lectin 1/metabolism , Th1 Cells/cytology , Th1 Cells/immunology , Th1 Cells/metabolism
8.
Sci Prog ; 104(2_suppl): 368504211026119, 2021 06.
Article in English | MEDLINE | ID: covidwho-1288516

ABSTRACT

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in a vast number of infections and deaths that deeply affect the world. When the virus encounters the host cell, it binds to angiotensin-converting enzyme 2, then the S protein of the virus is broken down by the transmembrane protease serine 2 with the help of furin, allowing the virus to enter the cell. The elevated inflammatory cytokines suggest that a cytokine storm, also known as cytokine release syndrome, may play a major role in the pathology of COVID-19. Therefore, the aim of this study is to investigate the relationship between circulating furin levels, disease severity, and inflammation in patients with SARS-CoV-2. A total of 52 SARS-CoV-2 patients and 36 healthy control participants were included in this study. SARS- CoV-2 patients were scored by the disease activity score. Serum furin, presepsin, and interleukin-6 (IL-6) levels were assessed using an enzyme-linked immunosorbent assay. The mean furin, presepsin, and IL-6 levels were significantly higher in the peripheral blood of SARS-CoV-2 compared to the controls (p < 0.001). There were close positive relationship between serum furin and IL-6, furin and presepsin, and furin and disease severity (r = 0.793, p < 0001; r = 0.521, p < 0.001; and r = 0,533, p < 0.001, respectively) in patients with SARS-CoV-2. These results suggest that furin may contribute to the exacerbation of SARS-CoV-2 infection and increased inflammation, and could be used as a predictor of disease severity in COVID-19 patients.


Subject(s)
COVID-19/blood , COVID-19/pathology , Furin/blood , Interleukin-6/blood , Lipopolysaccharide Receptors/blood , Peptide Fragments/blood , SARS-CoV-2 , Adult , Aged , Biomarkers/blood , Female , Humans , Lipopolysaccharide Receptors/genetics , Lipopolysaccharide Receptors/metabolism , Male , Middle Aged , Peptide Fragments/genetics , Peptide Fragments/metabolism
9.
Front Immunol ; 12: 651656, 2021.
Article in English | MEDLINE | ID: covidwho-1211812

ABSTRACT

Although immune dysfunction is a key feature of coronavirus disease 2019 (COVID-19), the metabolism-related mechanisms remain elusive. Here, by reanalyzing single-cell RNA sequencing data, we delineated metabolic remodeling in peripheral blood mononuclear cells (PBMCs) to elucidate the metabolic mechanisms that may lead to the progression of severe COVID-19. After scoring the metabolism-related biological processes and signaling pathways, we found that mono-CD14+ cells expressed higher levels of glycolysis-related genes (PKM, LDHA and PKM) and PPP-related genes (PGD and TKT) in severe patients than in mild patients. These genes may contribute to the hyperinflammation in mono-CD14+ cells of patients with severe COVID-19. The mono-CD16+ cell population in COVID-19 patients showed reduced transcription levels of genes related to lysine degradation (NSD1, KMT2E, and SETD2) and elevated transcription levels of genes involved in OXPHOS (ATP6V1B2, ATP5A1, ATP5E, and ATP5B), which may inhibit M2-like polarization. Plasma cells also expressed higher levels of the OXPHOS gene ATP13A3 in COVID-19 patients, which was positively associated with antibody secretion and survival of PCs. Moreover, enhanced glycolysis or OXPHOS was positively associated with the differentiation of memory B cells into plasmablasts or plasma cells. This study comprehensively investigated the metabolic features of peripheral immune cells and revealed that metabolic changes exacerbated inflammation in monocytes and promoted antibody secretion and cell survival in PCs in COVID-19 patients, especially those with severe disease.


Subject(s)
COVID-19/immunology , Glycolysis/genetics , Lysine/metabolism , Monocytes/metabolism , Single-Cell Analysis/methods , Adenosine Triphosphatases/blood , Adenosine Triphosphatases/genetics , Antibodies/metabolism , COVID-19/metabolism , COVID-19/physiopathology , Databases, Genetic , GPI-Linked Proteins/metabolism , Gene Ontology , Hematopoiesis/genetics , Humans , Inflammation/genetics , Inflammation/immunology , Inflammation/metabolism , Leukocytes, Mononuclear/immunology , Leukocytes, Mononuclear/metabolism , Leukocytes, Mononuclear/pathology , Lipopolysaccharide Receptors/metabolism , Lysine/genetics , Membrane Transport Proteins/blood , Membrane Transport Proteins/genetics , Metabolic Networks and Pathways/genetics , Metabolic Networks and Pathways/physiology , Monocytes/immunology , Monocytes/pathology , Oxidative Phosphorylation , RNA-Seq , Receptors, IgG/metabolism , Signal Transduction/genetics , Signal Transduction/immunology , Transcriptome/genetics
10.
Front Immunol ; 11: 580250, 2020.
Article in English | MEDLINE | ID: covidwho-918140

ABSTRACT

Little is known about the time-dependent immune responses in severe COVID-19. Data of 15 consecutive patients were sequentially recorded from intensive care unit admission. Lymphocyte subsets and total monocyte and subsets counts were monitored as well as the expression of HLA-DR. For 5 patients, SARS-CoV-2-specific T-cell polyfunctionality was assessed against Spike and Nucleoprotein SARS-CoV-2 peptides. Non-specific inflammation markers were increased in all patients. Median monocyte HLA-DR expression was below the 8,000 AB/C threshold defining acquired immunodepression. A "V" trend curve for lymphopenia, monocyte numbers, and HLA-DR expression was observed with a nadir between days 11 and 14 after symptoms' onset. Intermediate CD14++CD16+ monocytes increased early with a reduction in classic CD14++CD16- monocytes. Polyfunctional SARS-Cov-2-specific CD4 T-cells were present and functional, whereas virus-specific CD8 T-cells were less frequent and not efficient. We report a temporal variation of both innate and adaptive immunity in severe COVID-19 patients, helpful in guiding therapeutic decisions (e.g. anti-inflammatory vs. immunostimulatory ones). We describe a defect in virus-specific CD8 T-cells, a potential biomarker of clinical severity. These combined data also provide helpful knowledge for vaccine design. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/, identifier NCT04386395.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , COVID-19/immunology , Monocytes/immunology , SARS-CoV-2/immunology , Severity of Illness Index , Aged , Biomarkers , COVID-19/virology , Female , GPI-Linked Proteins/metabolism , HLA-DR Antigens/immunology , Humans , Immunity, Cellular , Lipopolysaccharide Receptors/metabolism , Longitudinal Studies , Male , Middle Aged , Prospective Studies , Receptors, IgG/metabolism , SARS-CoV-2/genetics
11.
EBioMedicine ; 61: 103039, 2020 Nov.
Article in English | MEDLINE | ID: covidwho-838297

ABSTRACT

The signalling receptor for LPS, CD14, is a key marker of, and facilitator for, pro-inflammatory macrophage function. Pro-inflammatory macrophage differentiation remains a process facilitating a broad array of disease pathologies, and has recently emerged as a potential target against cytokine storm in COVID19. Here, we perform a whole-genome CRISPR screen to identify essential nodes regulating CD14 expression in myeloid cells, using the differentiation of THP-1 cells as a starting point. This strategy uncovers many known pathways required for CD14 expression and regulating macrophage differentiation while additionally providing a list of novel targets either promoting or limiting this process. To speed translation of these results, we have then taken the approach of independently validating hits from the screen using well-curated small molecules. In this manner, we identify pharmacologically tractable hits that can either increase CD14 expression on non-differentiated monocytes or prevent CD14 upregulation during macrophage differentiation. An inhibitor for one of these targets, MAP2K3, translates through to studies on primary human monocytes, where it prevents upregulation of CD14 following M-CSF induced differentiation, and pro-inflammatory cytokine production in response to LPS. Therefore, this screening cascade has rapidly identified pharmacologically tractable nodes regulating a critical disease-relevant process.


Subject(s)
Cell Differentiation/drug effects , Lipopolysaccharide Receptors/metabolism , Macrophages/immunology , Macrophages/metabolism , Biomarkers , Cells, Cultured , Cytokines/metabolism , Humans , Immunophenotyping , Leukocytes, Mononuclear/drug effects , Leukocytes, Mononuclear/immunology , Leukocytes, Mononuclear/metabolism , Lipopolysaccharides/adverse effects , Macrophages/drug effects , THP-1 Cells
12.
EMBO Mol Med ; 12(10): e13038, 2020 10 07.
Article in English | MEDLINE | ID: covidwho-722035

ABSTRACT

Early in the COVID-19 pandemic, type 2 diabetes (T2D) was marked as a risk factor for severe disease and mortality. Inflammation is central to the aetiology of both conditions where variations in immune responses can mitigate or aggravate disease course. Identifying at-risk groups based on immunoinflammatory signatures is valuable in directing personalised care and developing potential targets for precision therapy. This observational study characterised immunophenotypic variation associated with COVID-19 severity in T2D. Broad-spectrum immunophenotyping quantified 15 leucocyte populations in peripheral circulation from a cohort of 45 hospitalised COVID-19 patients with and without T2D. Lymphocytopenia and specific loss of cytotoxic CD8+ lymphocytes were associated with severe COVID-19 and requirement for intensive care in both non-diabetic and T2D patients. A morphological anomaly of increased monocyte size and monocytopenia restricted to classical CD14Hi CD16- monocytes was specifically associated with severe COVID-19 in patients with T2D requiring intensive care. Increased expression of inflammatory markers reminiscent of the type 1 interferon pathway (IL6, IL8, CCL2, INFB1) underlaid the immunophenotype associated with T2D. These immunophenotypic and hyperinflammatory changes may contribute to increased voracity of COVID-19 in T2D. These findings allow precise identification of T2D patients with severe COVID-19 as well as provide evidence that the type 1 interferon pathway may be an actionable therapeutic target for future studies.


Subject(s)
COVID-19/pathology , Diabetes Mellitus, Type 2/pathology , Monocytes/physiology , Aged , COVID-19/complications , COVID-19/virology , Chemokine CCL2/genetics , Chemokine CCL2/metabolism , Diabetes Mellitus, Type 2/complications , Female , Humans , Immunophenotyping , Inflammation/etiology , Interleukin-6/genetics , Interleukin-6/metabolism , Leukocytes, Mononuclear/cytology , Leukocytes, Mononuclear/metabolism , Lipopolysaccharide Receptors/metabolism , Lymphopenia/diagnosis , Male , Middle Aged , Monocytes/cytology , Monocytes/pathology , Risk Factors , SARS-CoV-2/isolation & purification , Severity of Illness Index
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