Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 224
Filter
1.
Genome Biol ; 23(1): 55, 2022 02 16.
Article in English | MEDLINE | ID: covidwho-1785167

ABSTRACT

BACKGROUND: Multiplexing of samples in single-cell RNA-seq studies allows a significant reduction of the experimental costs, straightforward identification of doublets, increased cell throughput, and reduction of sample-specific batch effects. Recently published multiplexing techniques using oligo-conjugated antibodies or -lipids allow barcoding sample-specific cells, a process called "hashing." RESULTS: Here, we compare the hashing performance of TotalSeq-A and -C antibodies, custom synthesized lipids and MULTI-seq lipid hashes in four cell lines, both for single-cell RNA-seq and single-nucleus RNA-seq. We also compare TotalSeq-B antibodies with CellPlex reagents (10x Genomics) on human PBMCs and TotalSeq-B with different lipids on primary mouse tissues. Hashing efficiency was evaluated using the intrinsic genetic variation of the cell lines and mouse strains. Antibody hashing was further evaluated on clinical samples using PBMCs from healthy and SARS-CoV-2 infected patients, where we demonstrate a more affordable approach for large single-cell sequencing clinical studies, while simultaneously reducing batch effects. CONCLUSIONS: Benchmarking of different hashing strategies and computational pipelines indicates that correct demultiplexing can be achieved with both lipid- and antibody-hashed human cells and nuclei, with MULTISeqDemux as the preferred demultiplexing function and antibody-based hashing as the most efficient protocol on cells. On nuclei datasets, lipid hashing delivers the best results. Lipid hashing also outperforms antibodies on cells isolated from mouse brain. However, antibodies demonstrate better results on tissues like spleen or lung.


Subject(s)
COVID-19/blood , Sequence Analysis, RNA/methods , Single-Cell Analysis/methods , Animals , Antibodies/chemistry , Case-Control Studies , Cell Line, Tumor , Cell Nucleus/chemistry , Humans , Lipids/chemistry , Mice, Inbred BALB C , Mice, Inbred C57BL , Neutrophils/chemistry , Neutrophils/immunology , Neutrophils/virology
2.
Front Immunol ; 13: 842535, 2022.
Article in English | MEDLINE | ID: covidwho-1702591

ABSTRACT

Myeloid-derived suppressor cells (MDSCs) are generated under biological stress such as cancer, inflammatory tissue damage, and viral infection. In recent years, with occurrence of global infectious diseases, new discovery on MDSCs functions has been significantly expanded during viral infection and COVID-19. For a successful viral infection, pathogens viruses develop immune evasion strategies to avoid immune recognition. Numerous viruses induce the differentiation and expansion of MDSCs in order to suppress host immune responses including natural killer cells, antigen presenting cells, and T-cells. Moreover, MDSCs play an important role in regulation of immunopathogenesis by balancing viral infection and tissue damage. In this review article, we describe the overview of immunomodulation and genetic regulation of MDSCs during viral infection in the animal model and human studies. In addition, we include up-to-date review of role of MDSCs in SARS-CoV-2 infection and COVID-19. Finally, we discuss potential therapeutics targeting MDSCs.


Subject(s)
Immunomodulation/immunology , Macrophages/immunology , Myeloid-Derived Suppressor Cells/immunology , Neutrophils/immunology , SARS-CoV-2/immunology , Animals , COVID-19/immunology , Disease Models, Animal , Humans , Immune Evasion/immunology , Macrophages/cytology , Monocytes/cytology , Monocytes/immunology , Myeloid-Derived Suppressor Cells/cytology
3.
Acta Neuropathol Commun ; 10(1): 14, 2022 02 01.
Article in English | MEDLINE | ID: covidwho-1690864

ABSTRACT

Coronavirus disease 2019 (COVID-19) is associated with an increased risk of thrombotic events. Ischemic stroke in COVID-19 patients entails high severity and mortality rates. Here we aimed to analyze cerebral thrombi of COVID-19 patients with large vessel occlusion (LVO) acute ischemic stroke to expose molecular evidence for SARS-CoV-2 in the thrombus and to unravel any peculiar immune-thrombotic features. We conducted a systematic pathological analysis of cerebral thrombi retrieved by endovascular thrombectomy in patients with LVO stroke infected with COVID-19 (n = 7 patients) and non-covid LVO controls (n = 23). In thrombi of COVID-19 patients, the SARS-CoV-2 docking receptor ACE2 was mainly expressed in monocytes/macrophages and showed higher expression levels compared to controls. Using polymerase chain reaction and sequencing, we detected SARS-CoV-2 Clade20A, in the thrombus of one COVID-19 patient. Comparing thrombus composition of COVID-19 and control patients, we noted no overt differences in terms of red blood cells, fibrin, neutrophil extracellular traps (NETs), von Willebrand Factor (vWF), platelets and complement complex C5b-9. However, thrombi of COVID-19 patients showed increased neutrophil density (MPO+ cells) and a three-fold higher Neutrophil-to-Lymphocyte Ratio (tNLR). In the ROC analysis both neutrophils and tNLR had a good discriminative ability to differentiate thrombi of COVID-19 patients from controls. In summary, cerebral thrombi of COVID-19 patients can harbor SARS-CoV2 and are characterized by an increased neutrophil number and tNLR and higher ACE2 expression. These findings suggest neutrophils as the possible culprit in COVID-19-related thrombosis.


Subject(s)
Brain Ischemia/immunology , COVID-19/immunology , Immunity, Cellular/physiology , Intracranial Thrombosis/immunology , Neutrophils/immunology , Stroke/immunology , Aged , Aged, 80 and over , Angiotensin-Converting Enzyme 2/blood , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/immunology , Brain Ischemia/blood , Brain Ischemia/genetics , COVID-19/blood , COVID-19/genetics , Female , Humans , Intracranial Thrombosis/blood , Intracranial Thrombosis/genetics , Male , Mechanical Thrombolysis/methods , Middle Aged , Neutrophils/metabolism , Prospective Studies , SARS-CoV-2/genetics , SARS-CoV-2/immunology , SARS-CoV-2/metabolism , Stroke/blood , Stroke/genetics
4.
Viruses ; 14(2)2022 01 20.
Article in English | MEDLINE | ID: covidwho-1649018

ABSTRACT

While numerous studies have already compared the immune responses against SARS-CoV-2 in severely and mild-to-moderately ill COVID-19 patients, longitudinal trajectories are still scarce. We therefore set out to analyze serial blood samples from mild-to-moderately ill patients in order to define the immune landscapes for differently progressed disease stages. Twenty-two COVID-19 patients were subjected to consecutive venipuncture within seven days after diagnosis or admittance to hospital. Flow cytometry was performed to analyze peripheral blood immune cell compositions and their activation as were plasma levels of cytokines and SARS-CoV-2 specific immunoglobulins. Healthy donors served as controls. Integrating the kinetics of plasmablasts and SARS-CoV-2 specific antibodies allowed for the definition of three disease stages of early COVID-19. The incubation phase was characterized by a sharp increase in pro-inflammatory monocytes and terminally differentiated cytotoxic T cells. The latter correlated significantly with elevated concentrations of IP-10. Early acute infection featured a peak in PD-1+ cytotoxic T cells, plasmablasts and increasing titers of virus specific antibodies. During late acute infection, immature neutrophils were enriched, whereas all other parameters returned to baseline. Our findings will help to define landmarks that are indispensable for the refinement of new anti-viral and anti-inflammatory therapeutics, and may also inform clinicians to optimize treatment and prevent fatal outcomes.


Subject(s)
Antibodies, Viral/blood , COVID-19/immunology , COVID-19/physiopathology , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Acute Disease , Adult , Aged , Aged, 80 and over , Antibodies, Viral/immunology , Blood Cell Count , Chemokine CXCL10/blood , Chemokine CXCL10/immunology , Cytokines/blood , Cytokines/immunology , Female , Humans , Inflammation , Longitudinal Studies , Male , Middle Aged , Neutrophils/immunology , T-Lymphocytes, Cytotoxic/immunology , Young Adult
5.
J Immunol ; 208(4): 979-990, 2022 02 15.
Article in English | MEDLINE | ID: covidwho-1631932

ABSTRACT

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


Subject(s)
Bronchoalveolar Lavage Fluid/immunology , Cystic Fibrosis/immunology , Inflammation/immunology , Leukocyte L1 Antigen Complex/metabolism , Neutrophils/immunology , Peptides/metabolism , Respiratory System/metabolism , Child , Child, Preschool , Cystic Fibrosis/diagnosis , Female , Humans , Inflammation/diagnosis , Leukocyte L1 Antigen Complex/genetics , Leukocyte L1 Antigen Complex/immunology , Male , Neutrophil Activation , Oxidation-Reduction , Peptides/genetics , Peptides/immunology , Proteolysis
6.
Cytokine ; 151: 155804, 2022 03.
Article in English | MEDLINE | ID: covidwho-1630370

ABSTRACT

Coronavirus disease 2019 (COVID-19) is an infectious respiratory disorder caused by a new coronavirus called SARS-CoV-2. The pathophysiology of severe COVID-19 is associated with a "cytokine storm". IL-32 is a key modulator in the pathogenesis of various clinical conditions and is mostly induced by IL-8. IL-32 modulates important inflammatory pathways (including TNF-α, IL-6 and IL-1b), contributing to the pathogenesis of inflammatory diseases. Il-32 was never evaluated before in COVID-19 patients stratifying as mild-moderate and severe patients. A total of 64 COVID-19 patients, 27 healthy controls were consecutively enrolled in the study. Serum concentrations of biomarkers including IL-1ß, IL-10, IFN-γ, TNF-α and IL-6 were quantified by bead-based multiplex analysis and Serum concentration of IL-8 and IL-32 were determined by enzyme-linked immunosorbent assay (ELISA) kits. Interestingly, among the blood parameters, neutrophil and lymphocyte counts were significantly lower in severe COVID-19 patients than in the other, on the contrary, CRP was significantly higher in severe patients than in other groups. The cytokines that best distinguished controls from COVID-19 patients were IL-8 and IL-32, while IL-6 resulted the better variables for discriminate severe group. The best model performance for severe group was obtained by the combination of IL-32, IL-6, IFN-γ, and CRP serum concentration showing an AUC = 0.83. A cut off of 15 pg/ml of IL-6 greatly discriminate survivor from death patients. New insights related to the cytokine storm in COVID-19 patients, highlighting different severity of disease infection.


Subject(s)
COVID-19/blood , Cytokines/blood , Interleukin-8/blood , Interleukins/blood , Lung/immunology , Aged , Biomarkers/blood , COVID-19/immunology , Cytokine Release Syndrome/blood , Cytokine Release Syndrome/immunology , Cytokines/immunology , Female , Humans , Interleukin-10/blood , Interleukin-10/immunology , Interleukin-8/immunology , Interleukins/immunology , Lymphocyte Count/methods , Lymphocytes/immunology , Male , Middle Aged , Neutrophils/immunology , Prospective Studies , SARS-CoV-2/immunology
7.
Viruses ; 14(1)2021 12 22.
Article in English | MEDLINE | ID: covidwho-1636836

ABSTRACT

Human adenoviruses (HAdV) cause a variety of infections in human hosts, from self-limited upper respiratory tract infections in otherwise healthy people to fulminant pneumonia and death in immunocompromised patients. Many HAdV enter polarized epithelial cells by using the primary receptor, the Coxsackievirus and adenovirus receptor (CAR). Recently published data demonstrate that a potent neutrophil (PMN) chemoattractant, interleukin-8 (IL-8), stimulates airway epithelial cells to increase expression of the apical isoform of CAR (CAREx8), which results in increased epithelial HAdV type 5 (HAdV5) infection. However, the mechanism for PMN-enhanced epithelial HAdV5 transduction remains unclear. In this manuscript, the molecular mechanisms behind PMN mediated enhancement of epithelial HAdV5 transduction are characterized using an MDCK cell line that stably expresses human CAREx8 under a doxycycline inducible promoter (MDCK-CAREx8 cells). Contrary to our hypothesis, PMN exposure does not enhance HAdV5 entry by increasing CAREx8 expression nor through activation of non-specific epithelial endocytic pathways. Instead, PMN serine proteases are responsible for PMN-mediated enhancement of HAdV5 transduction in MDCK-CAREx8 cells. This is evidenced by reduced transduction upon inhibition of PMN serine proteases and increased transduction upon exposure to exogenous human neutrophil elastase (HNE). Furthermore, HNE exposure activates epithelial autophagic flux, which, even when triggered through other mechanisms, results in a similar enhancement of epithelial HAdV5 transduction. Inhibition of F-actin with cytochalasin D partially attenuates PMN mediated enhancement of HAdV transduction. Taken together, these findings suggest that HAdV5 can leverage innate immune responses to establish infections.


Subject(s)
Adenoviruses, Human/pathogenicity , Epithelial Cells/virology , Leukocyte Elastase/metabolism , Neutrophils/immunology , Virus Internalization , Adenoviruses, Human/immunology , Adenoviruses, Human/physiology , Animals , Autophagy , Coxsackie and Adenovirus Receptor-Like Membrane Protein/metabolism , Cytochalasin B/pharmacology , Dogs , Endocytosis , Humans , Immunity, Innate , Macrolides/pharmacology , Madin Darby Canine Kidney Cells , Receptors, Virus/metabolism
8.
Sci Rep ; 12(1): 638, 2022 01 12.
Article in English | MEDLINE | ID: covidwho-1621278

ABSTRACT

COVID-19 can cause acute respiratory distress syndrome, leading to death in many individuals. Evidence of a deleterious role of the innate immune system is accumulating, but the precise mechanisms involved remain unclear. In this study, we investigated the links between circulating innate phagocytes and severity in COVID-19 patients. We performed in-depth phenotyping of neutrophil and monocyte subpopulations and measured soluble activation markers in plasma. Additionally, anti-microbial functions (phagocytosis, oxidative burst, and NETosis) were evaluated on fresh cells from patients. Neutrophils and monocytes had a strikingly disturbed phenotype, and elevated concentrations of activation markers (calprotectin, myeloperoxidase, and neutrophil extracellular traps) were measured in plasma. Critical patients had increased CD13low immature neutrophils, LOX-1 + and CCR5 + immunosuppressive neutrophils, and HLA-DRlow downregulated monocytes. Markers of immature and immunosuppressive neutrophils were strongly associated with severity. Moreover, neutrophils and monocytes of critical patients had impaired antimicrobial functions, which correlated with organ dysfunction, severe infections, and mortality. Together, our results strongly argue in favor of a pivotal role of innate immunity in COVID-19 severe infections and pleads for targeted therapeutic options.


Subject(s)
COVID-19/immunology , Immunity, Innate , Immunocompromised Host , Adult , Aged , Female , Humans , Male , Middle Aged , Monocytes/immunology , Neutrophils/immunology , Phagocytes/immunology , Prognosis , Severity of Illness Index , Young Adult
9.
Biometals ; 35(1): 125-145, 2022 02.
Article in English | MEDLINE | ID: covidwho-1611429

ABSTRACT

The role of micronutrient deficiency in the pathogenesis of COVID-19 has been reviewed in the literature; however, the data are limited and conflicting. This study investigated the association between the status of essential metals, vitamins, and antioxidant enzyme activities in COVID-19 patients and disease severity. We recruited 155 patients, who were grouped into four classes based on the Adults guideline for the Management of Coronavirus Disease 2019 at King Faisal Specialist & Research Centre (KFSH&RC): asymptomatic (N = 16), mild (N = 49), moderate (N = 68), and severe (N = 22). We measured serum levels of copper (Cu), zinc (Zn), selenium (Se), vitamin D3, vitamin A, vitamin E, total antioxidant capacity, and superoxide dismutase (SOD). Among the patients, 30%, 25%, 37%, and 68% were deficient in Se (< 70.08 µg/L), Zn (< 0.693 µg/mL), vitamin A (< 0.343 µg/mL), and vitamin D3 (< 20.05 µg/L), respectively, and SOD activity was low. Among the patients, 28% had elevated Cu levels (> 1.401 µg/mL, KFSH&RC upper reference limit). Multiple regression analysis revealed an 18% decrease in Se levels in patients with severe symptoms, which increased to 30% after adjusting the model for inflammatory markers. Regardless of inflammation, Se was independently associated with COVID-19 severity. In contrast, a 50% increase in Cu levels was associated with disease severity only after adjusting for C-reactive protein, reflecting its possible inflammatory and pro-oxidant role in COVID-19 pathogenesis. We noted an imbalance in the ratio between Cu and Zn, with ~ 83% of patients having a Cu/Zn ratio > 1, which is an indicator of inflammation. Cu-to-Zn ratio increased to 45% in patients with mild symptoms and 34%-36% in patients with moderate symptoms compared to asymptomatic patients. These relationships were only obtained when one of the laboratory parameters (lymphocyte or monocyte) or inflammatory markers (neutrophil-to-lymphocyte ratio) was included in the regression model. These findings suggest that Cu/Zn might further exacerbate inflammation in COVID-19 patients and might be synergistically associated with disease severity. A 23% decrease in vitamin A was seen in patients with severe symptoms, which disappeared after adjusting for inflammatory markers. This finding may highlight the potential role of inflammation in mediating the relationship between COVID-19 severity and vitamin A levels. Despite our patients' low status of Zn, vitamin D3, and antioxidant enzyme (SOD), there is no evidence of their role in COVID-19 progression. Our findings reinforce that deficiency or excess of certain micronutrients plays a role in the pathogenesis of COVID-19. More studies are required to support our results.


Subject(s)
COVID-19/blood , Copper/blood , SARS-CoV-2/pathogenicity , Selenium/blood , Zinc/blood , Adolescent , Adult , Aged , Aged, 80 and over , Asymptomatic Diseases , C-Reactive Protein/metabolism , COVID-19/immunology , COVID-19/pathology , COVID-19/virology , Cell Count , Cholecalciferol/blood , Humans , Lymphocytes/immunology , Lymphocytes/virology , Middle Aged , Monocytes/immunology , Monocytes/virology , Neutrophils/immunology , Neutrophils/virology , Regression Analysis , SARS-CoV-2/growth & development , Severity of Illness Index , Superoxide Dismutase/blood , Vitamin A/blood , Vitamin E/blood
10.
J Immunol ; 208(3): 685-696, 2022 02 01.
Article in English | MEDLINE | ID: covidwho-1604665

ABSTRACT

Immune response dysregulation plays a key role in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pathogenesis. In this study, we evaluated immune and endothelial blood cell profiles of patients with coronavirus disease 2019 (COVID-19) to determine critical differences between those with mild, moderate, or severe COVID-19 using spectral flow cytometry. We examined a suite of immune phenotypes, including monocytes, T cells, NK cells, B cells, endothelial cells, and neutrophils, alongside surface and intracellular markers of activation. Our results showed progressive lymphopenia and depletion of T cell subsets (CD3+, CD4+, and CD8+) in patients with severe disease and a significant increase in the CD56+CD14+Ki67+IFN-γ+ monocyte population in patients with moderate and severe COVID-19 that has not been previously described. Enhanced circulating endothelial cells (CD45-CD31+CD34+CD146+), circulating endothelial progenitors (CD45-CD31+CD34+/-CD146-), and neutrophils (CD11b+CD66b+) were coevaluated for COVID-19 severity. Spearman correlation analysis demonstrated the synergism among age, obesity, and hypertension with upregulated CD56+ monocytes, endothelial cells, and decreased T cells that lead to severe outcomes of SARS-CoV-2 infection. Circulating monocytes and endothelial cells may represent important cellular markers for monitoring postacute sequelae and impacts of SARS-CoV-2 infection during convalescence and for their role in immune host defense in high-risk adults after vaccination.


Subject(s)
COVID-19/immunology , Endothelial Cells/immunology , Monocytes/immunology , SARS-CoV-2 , Adolescent , Adult , Age Factors , Aged , Antibodies, Viral/biosynthesis , Antibodies, Viral/immunology , Biomarkers , CD56 Antigen/analysis , COVID-19/blood , COVID-19/epidemiology , Child , Comorbidity , Endothelial Cells/chemistry , Female , Flow Cytometry , Humans , Hypertension/epidemiology , Hypertension/immunology , Immunophenotyping , Lymphocyte Activation , Lymphocyte Subsets/immunology , Lymphopenia/etiology , Lymphopenia/immunology , Male , Middle Aged , Monocytes/chemistry , Neutrophils/immunology , Obesity/epidemiology , Obesity/immunology , Platelet Endothelial Cell Adhesion Molecule-1/analysis , SARS-CoV-2/immunology , Severity of Illness Index , Spike Glycoprotein, Coronavirus/immunology , Young Adult
11.
Sci Rep ; 11(1): 22463, 2021 11 17.
Article in English | MEDLINE | ID: covidwho-1592758

ABSTRACT

SARS-CoV-2 infection results in a spectrum of outcomes from no symptoms to widely varying degrees of illness to death. A better understanding of the immune response to SARS-CoV-2 infection and subsequent, often excessive, inflammation may inform treatment decisions and reveal opportunities for therapy. We studied immune cell subpopulations and their associations with clinical parameters in a cohort of 26 patients with COVID-19. Following informed consent, we collected blood samples from hospitalized patients with COVID-19 within 72 h of admission. Flow cytometry was used to analyze white blood cell subpopulations. Plasma levels of cytokines and chemokines were measured using ELISA. Neutrophils undergoing neutrophil extracellular traps (NET) formation were evaluated in blood smears. We examined the immunophenotype of patients with COVID-19 in comparison to that of SARS-CoV-2 negative controls. A novel subset of pro-inflammatory neutrophils expressing a high level of dual endothelin-1 and VEGF signal peptide-activated receptor (DEspR) at the cell surface was found to be associated with elevated circulating CCL23, increased NETosis, and critical-severity COVID-19 illness. The potential to target this subpopulation of neutrophils to reduce secondary tissue damage caused by SARS-CoV-2 infection warrants further investigation.


Subject(s)
COVID-19/immunology , Neutrophils/immunology , Pseudogenes/immunology , Aged , Chemokines/metabolism , Cohort Studies , Critical Illness , Cytokines/metabolism , Enzyme-Linked Immunosorbent Assay/methods , Extracellular Traps/metabolism , Female , Humans , Inflammation/metabolism , Male , Middle Aged , Neutrophils/metabolism , Pseudogenes/genetics , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Severity of Illness Index
13.
Br J Haematol ; 196(5): 1159-1169, 2022 03.
Article in English | MEDLINE | ID: covidwho-1583669

ABSTRACT

COVID-19 has compelled scientists to better describe its pathophysiology to find new therapeutic approaches. While risk factors, such as older age, obesity, and diabetes mellitus, suggest a central role of endothelial cells (ECs), autopsies have revealed clots in the pulmonary microvasculature that are rich in neutrophils and DNA traps produced by these cells, called neutrophil extracellular traps (NETs.) Submicron extracellular vesicles, called microparticles (MPs), are described in several diseases as being involved in pro-inflammatory pathways. Therefore, in this study, we analyzed three patient groups: one for which intubation was not necessary, an intubated group, and one group after extubation. In the most severe group, the intubated group, platelet-derived MPs and endothelial cell (EC)-derived MPs exhibited increased concentration and size, when compared to uninfected controls. MPs of intubated COVID-19 patients triggered EC death and overexpression of two adhesion molecules: P-selectin and vascular cell adhesion molecule-1 (VCAM-1). Strikingly, neutrophil adhesion and NET production were increased following incubation with these ECs. Importantly, we also found that preincubation of these COVID-19 MPs with the phosphatidylserine capping endogenous protein, annexin A5, abolished cytotoxicity, P-selectin and VCAM-1 induction, all like increases in neutrophil adhesion and NET release. Taken together, our results reveal that MPs play a key role in COVID-19 pathophysiology and point to a potential therapeutic: annexin A5.


Subject(s)
COVID-19/immunology , Cell-Derived Microparticles/immunology , Endothelial Cells/immunology , Neutrophils/immunology , SARS-CoV-2/immunology , COVID-19/pathology , COVID-19/therapy , Cell Adhesion , Cell Death , Cell-Derived Microparticles/pathology , Cells, Cultured , Endothelial Cells/pathology , Extracellular Traps/immunology , Humans , Inflammation/immunology , Inflammation/pathology , Intubation , Neutrophils/pathology , Phosphatidylserines/immunology
14.
Eur J Med Res ; 26(1): 146, 2021 Dec 17.
Article in English | MEDLINE | ID: covidwho-1582003

ABSTRACT

BACKGROUND: At the end of 2019, the world witnessed the emergence and ravages of a viral infection induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Also known as the coronavirus disease 2019 (COVID-19), it has been identified as a public health emergency of international concern (PHEIC) by the World Health Organization (WHO) because of its severity. METHODS: The gene data of 51 samples were extracted from the GSE150316 and GSE147507 data set and then processed by means of the programming language R, through which the differentially expressed genes (DEGs) that meet the standards were screened. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed on the selected DEGs to understand the functions and approaches of DEGs. The online tool STRING was employed to construct a protein-protein interaction (PPI) network of DEGs and, in turn, to identify hub genes. RESULTS: A total of 52 intersection genes were obtained through DEG identification. Through the GO analysis, we realized that the biological processes (BPs) that have the deepest impact on the human body after SARS-CoV-2 infection are various immune responses. By using STRING to construct a PPI network, 10 hub genes were identified, including IFIH1, DDX58, ISG15, EGR1, OASL, SAMD9, SAMD9L, XAF1, IFITM1, and TNFSF10. CONCLUSION: The results of this study will hopefully provide guidance for future studies on the pathophysiological mechanism of SARS-CoV-2 infection.


Subject(s)
COVID-19/genetics , Computational Biology/methods , Gene Expression Regulation/genetics , Lung/pathology , Protein Interaction Maps/genetics , COVID-19/pathology , Databases, Genetic , Gene Expression Profiling , Gene Ontology , Humans , Immunity, Humoral/genetics , Immunity, Humoral/immunology , Lung/virology , Neutrophil Activation/genetics , Neutrophil Activation/immunology , Neutrophils/immunology , SARS-CoV-2 , Transcriptome/genetics
15.
Nat Immunol ; 23(1): 23-32, 2022 01.
Article in English | MEDLINE | ID: covidwho-1585822

ABSTRACT

Systemic immune cell dynamics during coronavirus disease 2019 (COVID-19) are extensively documented, but these are less well studied in the (upper) respiratory tract, where severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replicates1-6. Here, we characterized nasal and systemic immune cells in individuals with COVID-19 who were hospitalized or convalescent and compared the immune cells to those seen in healthy donors. We observed increased nasal granulocytes, monocytes, CD11c+ natural killer (NK) cells and CD4+ T effector cells during acute COVID-19. The mucosal proinflammatory populations positively associated with peripheral blood human leukocyte antigen (HLA)-DRlow monocytes, CD38+PD1+CD4+ T effector (Teff) cells and plasmablasts. However, there was no general lymphopenia in nasal mucosa, unlike in peripheral blood. Moreover, nasal neutrophils negatively associated with oxygen saturation levels in blood. Following convalescence, nasal immune cells mostly normalized, except for CD127+ granulocytes and CD38+CD8+ tissue-resident memory T cells (TRM). SARS-CoV-2-specific CD8+ T cells persisted at least 2 months after viral clearance in the nasal mucosa, indicating that COVID-19 has both transient and long-term effects on upper respiratory tract immune responses.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Nasopharynx/immunology , Nose/cytology , Respiratory Mucosa/immunology , SARS-CoV-2/immunology , Antibodies, Viral/blood , COVID-19/immunology , COVID-19/pathology , Granulocytes/immunology , HLA-DR Antigens/metabolism , Humans , Killer Cells, Natural/immunology , Monocytes/immunology , Nasopharynx/cytology , Nasopharynx/virology , Neutrophils/immunology , Nose/immunology , Nose/virology , Prospective Studies , Respiratory Mucosa/cytology , Respiratory Mucosa/virology
16.
JCI Insight ; 7(2)2022 01 25.
Article in English | MEDLINE | ID: covidwho-1575230

ABSTRACT

Acute respiratory distress syndrome (ARDS) is a life-threatening syndrome, constituted by respiratory failure and diffuse alveolar damage that results from dysregulated local and systemic immune activation, causing pulmonary vascular, parenchymal, and alveolar damage. SARS-CoV-2 infection has become the dominant cause of ARDS worldwide, and emerging evidence implicates neutrophils and their cytotoxic arsenal of effector functions as central drivers of immune-mediated lung injury in COVID-19 ARDS. However, key outstanding questions are whether COVID-19 drives a unique program of neutrophil activation or effector functions that contribute to the severe pathogenesis of this pandemic illness and whether this unique neutrophil response can be targeted to attenuate disease. Using a combination of high-dimensional single-cell analysis and ex vivo functional assays of neutrophils from patients with COVID-19 ARDS, compared with those with non-COVID ARDS (caused by bacterial pneumonia), we identified a functionally distinct landscape of neutrophil activation in COVID-19 ARDS that was intrinsically programmed during SARS-CoV-2 infection. Furthermore, neutrophils in COVID-19 ARDS were functionally primed to produce high amounts of neutrophil extracellular traps. Surprisingly, this unique pathological program of neutrophil priming escaped conventional therapy with dexamethasone, thereby revealing a promising target for adjunctive immunotherapy in severe COVID-19.


Subject(s)
COVID-19/immunology , Extracellular Traps/immunology , Neutrophil Activation , Neutrophils/immunology , Respiratory Distress Syndrome/immunology , SARS-CoV-2/immunology , Adult , Aged , Aged, 80 and over , COVID-19/pathology , Female , Humans , Male , Middle Aged , Neutrophils/pathology , Pneumonia, Bacterial/immunology , Pneumonia, Bacterial/pathology , Respiratory Distress Syndrome/pathology , Severity of Illness Index
17.
Eur J Immunol ; 52(3): 484-502, 2022 03.
Article in English | MEDLINE | ID: covidwho-1555185

ABSTRACT

To better understand the mechanisms at the basis of neutrophil functions during SARS-CoV-2, we studied patients with severe COVID-19 pneumonia. They had high blood proportion of degranulated neutrophils and elevated plasma levels of myeloperoxidase (MPO), elastase, and MPO-DNA complexes, which are typical markers of neutrophil extracellular traps (NET). Their neutrophils display dysfunctional mitochondria, defective oxidative burst, increased glycolysis, glycogen accumulation in the cytoplasm, and increase glycogenolysis. Hypoxia-inducible factor 1α (ΗΙF-1α) is stabilized in such cells, and it controls the level of glycogen phosphorylase L (PYGL), a key enzyme in glycogenolysis. Inhibiting PYGL abolishes the ability of neutrophils to produce NET. Patients displayed significant increases of plasma levels of molecules involved in the regulation of neutrophils' function including CCL2, CXCL10, CCL20, IL-18, IL-3, IL-6, G-CSF, GM-CSF, IFN-γ. Our data suggest that metabolic remodelling is vital for the formation of NET and for boosting neutrophil inflammatory response, thus, suggesting that modulating ΗΙF-1α or PYGL could represent a novel approach for innovative therapies.


Subject(s)
COVID-19/immunology , COVID-19/metabolism , Neutrophils/immunology , Neutrophils/metabolism , SARS-CoV-2 , Adult , Aged , Aged, 80 and over , COVID-19/blood , Case-Control Studies , Cohort Studies , Cytokines/blood , Extracellular Traps/immunology , Extracellular Traps/metabolism , Female , Glycogen Phosphorylase, Liver Form/blood , Granulocytes/immunology , Granulocytes/metabolism , Humans , Hypoxia-Inducible Factor 1, alpha Subunit/blood , Male , Metabolic Networks and Pathways/genetics , Metabolic Networks and Pathways/immunology , Middle Aged , Neutrophil Activation , Peroxidase/blood , Respiratory Burst , Severity of Illness Index
18.
Viruses ; 13(11)2021 11 21.
Article in English | MEDLINE | ID: covidwho-1538550

ABSTRACT

A cytokine storm is an abnormal discharge of soluble mediators following an inappropriate inflammatory response that leads to immunopathological events. Cytokine storms can occur after severe infections as well as in non-infectious situations where inflammatory cytokine responses are initiated, then exaggerated, but fail to return to homeostasis. Neutrophils, macrophages, mast cells, and natural killer cells are among the innate leukocytes that contribute to the pathogenesis of cytokine storms. Neutrophils participate as mediators of inflammation and have roles in promoting homeostatic conditions following pathological inflammation. This review highlights the advances in understanding the mechanisms governing neutrophilic inflammation against viral and bacterial pathogens, in cancers, and in autoimmune diseases, and how neutrophils could influence the development of cytokine storm syndromes. Evidence for the destructive potential of neutrophils in their capacity to contribute to the onset of cytokine storm syndromes is presented across a multitude of clinical scenarios. Further, a variety of potential therapeutic strategies that target neutrophils are discussed in the context of suppressing multiple inflammatory conditions.


Subject(s)
Autoimmune Diseases/immunology , Cytokine Release Syndrome , Cytokines/immunology , Inflammation/immunology , Neoplasms/immunology , Animals , Humans , Immunity, Innate , Neutrophils/cytology , Neutrophils/immunology
19.
Front Immunol ; 12: 767319, 2021.
Article in English | MEDLINE | ID: covidwho-1538373

ABSTRACT

The importance of innate immune cells to sense and respond to their physical environment is becoming increasingly recognized. Innate immune cells (e.g. macrophages and neutrophils) are able to receive mechanical signals through several mechanisms. In this review, we discuss the role of mechanosensitive ion channels, such as Piezo1 and transient receptor potential vanilloid 4 (TRPV4), and cell adhesion molecules, such as integrins, selectins, and cadherins in biology and human disease. Furthermore, we explain that these mechanical stimuli activate intracellular signaling pathways, such as MAPK (p38, JNK), YAP/TAZ, EDN1, NF-kB, and HIF-1α, to induce protein conformation changes and modulate gene expression to drive cellular function. Understanding the mechanisms by which immune cells interpret mechanosensitive information presents potential targets to treat human disease. Important areas of future study in this area include autoimmune, allergic, infectious, and malignant conditions.


Subject(s)
Immunity, Innate/immunology , Macrophages/immunology , Mechanotransduction, Cellular/immunology , Neutrophils/immunology , Signal Transduction/immunology , Animals , Cytokines/immunology , Cytokines/metabolism , Humans , Ion Channels/immunology , Ion Channels/metabolism , Macrophages/metabolism , Neutrophils/metabolism , TRPV Cation Channels/immunology , TRPV Cation Channels/metabolism
20.
Front Immunol ; 12: 758588, 2021.
Article in English | MEDLINE | ID: covidwho-1528821

ABSTRACT

Reactive oxygen species (ROS) are a group of oxygen-containing highly-reactive molecules produced from oxidative metabolic processes or in response to intracellular signals like cytokines and external stimuli like pathogen attack. They regulate a range of physiological processes and are involved in innate immune responses against infectious agents. Deregulation of ROS contributes to a plethora of disease conditions. Sialic acids are carbohydrates, present on cell surfaces or soluble proteins. Sialic acid-binding immunoglobulin-like lectins (Siglecs) recognize and bind to sialic acids. These are widely expressed on various types of immune cells. Siglecs modulate immune activation and can promote or inhibit ROS generation under different contexts. Siglecs promote ROS-dependent cell death in neutrophils and eosinophils while limiting oxidative stress associated with chronic obstructive pulmonary disease (COPD), sickle cell disease (SCD), coronavirus disease-2019 (COVID-19), etc. This review distinguishes itself in summarizing the current understanding of the role of Siglecs in moderating ROS production and their distinct effect on different immune cells; that ultimately determine the cellular response and the disease outcome. This is an important field of investigation having scope for both expansion and medical importance.


Subject(s)
Reactive Oxygen Species/immunology , Sialic Acid Binding Immunoglobulin-like Lectins/immunology , Animals , Eosinophils/immunology , Humans , Neutrophils/immunology
SELECTION OF CITATIONS
SEARCH DETAIL