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1.
Nat Rev Immunol ; 20(6): 352-353, 2020 06.
Article in English | MEDLINE | ID: covidwho-1550294
3.
BMC Genom Data ; 22(1): 49, 2021 11 14.
Article in English | MEDLINE | ID: covidwho-1518254

ABSTRACT

BACKGROUND: There is an urgent need to understand the key events driving pathogenesis of severe COVID-19 disease, so that precise treatment can be instituted. In this respect NETosis is gaining increased attention in the scientific community, as an important pathological process contributing to mortality. We sought to test if indeed there exists robust evidence of NETosis in multiple transcriptomic data sets from human subjects with severe COVID-19 disease. Gene set enrichment analysis was performed to test for up-regulation of gene set functional in NETosis in the blood of patients with COVID-19 illness. RESULTS: Blood gene expression functional in NETosis increased with severity of illness, showed negative correlation with blood oxygen saturation, and was validated in the lung of COVID-19 non-survivors. Temporal expression of IL-6 was compared between severe and moderate illness with COVID-19. Unsupervised clustering was performed to reveal co-expression of IL-6 with complement genes. In severe COVID-19 illness, there is transcriptional evidence of activation of NETosis, complement and coagulation cascade, and negative correlation between NETosis and respiratory function (oxygen saturation). An early spike in IL-6 is observed in severe COVID-19 illness that is correlated with complement activation. CONCLUSIONS: Based on the transcriptional dynamics of IL-6 expression and its downstream effect on complement activation, we constructed a model that links early spike in IL-6 level with persistent and self-perpetuating complement activation, NETosis, immunothrombosis and respiratory dysfunction. Our model supports the early initiation of anti-IL6 therapy in severe COVID-19 disease before the life-threatening complications of the disease can perpetuate themselves autonomously.


Subject(s)
COVID-19/immunology , Extracellular Traps , Interleukin-6 , Thrombosis/virology , Transcriptome , COVID-19/pathology , Complement System Proteins/genetics , Humans , Interleukin-6/genetics , Oxygen
4.
Front Immunol ; 12: 714833, 2021.
Article in English | MEDLINE | ID: covidwho-1506100

ABSTRACT

Background: The most severe cases of Coronavirus-Disease-2019 (COVID-19) develop into Acute Respiratory Distress Syndrome (ARDS). It has been proposed that oxygenation may be inhibited by extracellular deoxyribonucleic acid (DNA) in the form of neutrophil extracellular traps (NETs). Dornase alfa (Pulmozyme, Genentech) is recombinant human deoxyribonuclease I that acts as a mucolytic by cleaving and degrading extracellular DNA. We performed a pilot study to evaluate the effects of dornase alfa in patients with ARDS secondary to COVID-19. Methods: We performed a pilot, non-randomized, case-controlled clinical trial of inhaled dornase for patients who developed ARDS secondary to COVID-19 pneumonia. Results: Improvement in arterial oxygen saturation to inhaled fraction of oxygen ratio (PaO2/FiO2) was noted in the treatment group compared to control at day 2 (95% CI, 2.96 to 95.66, P-value = 0.038), as well as in static lung compliance at days 3 through 5 (95% CI, 4.8 to 19.1 mL/cmH2O, 2.7 to 16.5 mL/cmH2O, and 5.3 to 19.2 mL/cmH2O, respectively). These effects were not sustained at 14 days. A reduction in bronchoalveolar lavage fluid (BALF) myeloperoxidase-DNA (DNA : MPO) complexes (95% CI, -14.7 to -1.32, P-value = 0.01) was observed after therapy with dornase alfa. Conclusion: Treatment with dornase alfa was associated with improved oxygenation and decreased DNA : MPO complexes in BALF. The positive effects, however, were limited to the time of drug delivery. These data suggest that degradation of extracellular DNA associated with NETs or other structures by inhaled dornase alfa can be beneficial. We propose a more extensive clinical trial is warranted. Clinical Trial Registration: ClinicalTrials.gov, Identifier: NCT04402970.


Subject(s)
COVID-19/drug therapy , Deoxyribonuclease I/therapeutic use , Respiratory Distress Syndrome/drug therapy , SARS-CoV-2/physiology , Administration, Inhalation , Adult , Aged , Aged, 80 and over , Case-Control Studies , DNA/metabolism , Extracellular Traps/metabolism , Female , Humans , Male , Middle Aged , Oxygen Consumption/drug effects , Peroxidase/metabolism , Pilot Projects , Recombinant Proteins/therapeutic use , Young Adult
5.
Front Immunol ; 12: 689866, 2021.
Article in English | MEDLINE | ID: covidwho-1503883

ABSTRACT

Rapid recruitment of neutrophils to an inflamed site is one of the hallmarks of an effective host defense mechanism. The main pathway through which this happens is by the innate immune response. Neutrophils, which play an important part in innate immune defense, migrate into lungs through the modulation actions of chemokines to execute a variety of pro-inflammatory functions. Despite the importance of chemokines in host immunity, little has been discussed on their roles in host immunity. A holistic understanding of neutrophil recruitment, pattern recognition pathways, the roles of chemokines and the pathophysiological roles of neutrophils in host immunity may allow for new approaches in the treatment of infectious and inflammatory disease of the lung. Herein, this review aims at highlighting some of the developments in lung neutrophil-immunity by focusing on the functions and roles of CXC/CC chemokines and pattern recognition receptors in neutrophil immunity during pulmonary inflammations. The pathophysiological roles of neutrophils in COVID-19 and thromboembolism have also been summarized. We finally summarized various neutrophil biomarkers that can be utilized as prognostic molecules in pulmonary inflammations and discussed various neutrophil-targeted therapies for neutrophil-driven pulmonary inflammatory diseases.


Subject(s)
Immunity, Innate/immunology , Neutrophils/immunology , Pneumonia/immunology , Biomarkers/blood , COVID-19/immunology , Cell Degranulation/immunology , Chemokines/immunology , Clinical Trials as Topic , Extracellular Traps/immunology , Humans , Integrins/immunology , Lung/immunology , Lung/pathology , Neutrophils/drug effects , Pneumonia/diagnosis , Pneumonia/drug therapy , Receptors, Pattern Recognition/immunology , Respiratory Burst/immunology , SARS-CoV-2 , Thromboembolism/immunology
6.
Int J Mol Sci ; 22(14)2021 Jul 06.
Article in English | MEDLINE | ID: covidwho-1502438

ABSTRACT

Neutrophils form sticky web-like structures known as neutrophil extracellular traps (NETs) as part of innate immune response. NETs are decondensed extracellular chromatin filaments comprising nuclear and cytoplasmic proteins. NETs have been implicated in many gastrointestinal diseases including colorectal cancer (CRC). However, the regulatory mechanisms of NET formation and potential pharmacological inhibitors in the context of CRC have not been thoroughly discussed. In this review, we intend to highlight roles of NETs in CRC progression and metastasis as well as the potential of targeting NETs during colon cancer therapy.


Subject(s)
Colorectal Neoplasms/immunology , Colorectal Neoplasms/pathology , Extracellular Traps/immunology , Neutrophils/immunology , Neutrophils/pathology , Animals , Disease Progression , Extracellular Traps/physiology , Humans , Neoplasm Metastasis/immunology
7.
Cells ; 10(9)2021 08 26.
Article in English | MEDLINE | ID: covidwho-1458477

ABSTRACT

The enlightenment of the formation of neutrophil extracellular traps (NETs) as a part of the innate immune system shed new insights into the pathologies of various diseases. The initial idea that NETs are a pivotal defense structure was gradually amended due to several deleterious effects in consecutive investigations. NETs formation is now considered a double-edged sword. The harmful effects are not limited to the induction of inflammation by NETs remnants but also include occlusions caused by aggregated NETs (aggNETs). The latter carries the risk of occluding tubular structures like vessels or ducts and appear to be associated with the pathologies of various diseases. In addition to life-threatening vascular clogging, other occlusions include painful stone formation in the biliary system, the kidneys, the prostate, and the appendix. AggNETs are also prone to occlude the ductal system of exocrine glands, as seen in ocular glands, salivary glands, and others. Last, but not least, they also clog the pancreatic ducts in a murine model of neutrophilia. In this regard, elucidating the mechanism of NETs-dependent occlusions is of crucial importance for the development of new therapeutic approaches. Therefore, the purpose of this review is to address the putative mechanisms of NETs-associated occlusions in the pathogenesis of disease, as well as prospective treatment modalities.


Subject(s)
Embolism/immunology , Extracellular Traps/physiology , Thrombosis/immunology , Animals , Body Fluids/immunology , Body Fluids/physiology , Embolism/physiopathology , Extracellular Traps/immunology , Extracellular Traps/metabolism , Humans , Inflammation/pathology , Neutrophils/immunology , Prospective Studies , Thrombosis/physiopathology
8.
Front Immunol ; 12: 689966, 2021.
Article in English | MEDLINE | ID: covidwho-1441106

ABSTRACT

Background: Most of the explanatory and prognostic models of COVID-19 lack of a comprehensive assessment of the wide COVID-19 spectrum of abnormalities. The aim of this study was to unveil novel biological features to explain COVID-19 severity and prognosis (death and disease progression). Methods: A predictive model for COVID-19 severity in 121 patients was constructed by ordinal logistic regression calculating odds ratio (OR) with 95% confidence intervals (95% CI) for a set of clinical, immunological, metabolomic, and other biological traits. The accuracy and calibration of the model was tested with the area under the curve (AUC), Somer's D, and calibration plot. Hazard ratios with 95% CI for adverse outcomes were calculated with a Cox proportional-hazards model. Results: The explanatory variables for COVID-19 severity were the body mass index (BMI), hemoglobin, albumin, 3-Hydroxyisovaleric acid, CD8+ effector memory T cells, Th1 cells, low-density granulocytes, monocyte chemoattractant protein-1, plasma TRIM63, and circulating neutrophil extracellular traps. The model showed an outstanding performance with an optimism-adjusted AUC of 0.999, and Somer's D of 0.999. The predictive variables for adverse outcomes in COVID-19 were severe and critical disease diagnosis, BMI, lactate dehydrogenase, Troponin I, neutrophil/lymphocyte ratio, serum levels of IP-10, malic acid, 3, 4 di-hydroxybutanoic acid, citric acid, myoinositol, and cystine. Conclusions: Herein, we unveil novel immunological and metabolomic features associated with COVID-19 severity and prognosis. Our models encompass the interplay among innate and adaptive immunity, inflammation-induced muscle atrophy and hypoxia as the main drivers of COVID-19 severity.


Subject(s)
COVID-19 , SARS-CoV-2 , Severity of Illness Index , Adult , Blood Coagulation , Body Mass Index , COVID-19/blood , COVID-19/immunology , COVID-19/metabolism , Cytokines/blood , Extracellular Traps/immunology , Female , Hemoglobins/analysis , Humans , Male , Metabolome , Middle Aged , Muscular Atrophy , Neutrophils/immunology , Phenotype , Prognosis , Serum Albumin, Human/analysis , T-Lymphocytes/immunology , Valerates/blood
9.
Front Cell Infect Microbiol ; 11: 694186, 2021.
Article in English | MEDLINE | ID: covidwho-1441101

ABSTRACT

The severity of coronavirus disease 19 (COVID-19) is associated with neutrophil extracellular trap (NET) formation. During NET formation, cytotoxic extracellular histones are released, the presence of which is linked to the initiation and progression of several acute inflammatory diseases. Here we study the presence and evolution of extracellular histone H3 and several other neutrophil-related molecules and damage-associated molecular patterns (DAMPs) in the plasma of 117 COVID-19-positive ICU patients. We demonstrate that at ICU admission the levels of histone H3, MPO, and DNA-MPO complex were all significantly increased in COVID-19-positive patients compared to control samples. Furthermore, in a subset of 54 patients, the levels of each marker remained increased after 4+ days compared to admission. Histone H3 was found in 28% of the patients on admission to the ICU and in 50% of the patients during their stay at the ICU. Notably, in 47% of histone-positive patients, we observed proteolysis of histone in their plasma. The overall presence of histone H3 during ICU stay was associated with thromboembolic events and secondary infection, and non-cleaved histone H3 was associated with the need for vasoactive treatment, invasive ventilation, and the development of acute kidney injury. Our data support the validity of treatments that aim to reduce NET formation and additionally underscore that more targeted therapies focused on the neutralization of histones should be considered as treatment options for severe COVID-19 patients.


Subject(s)
COVID-19 , Extracellular Traps , Histones , Humans , Intensive Care Units , SARS-CoV-2
10.
Cells ; 10(10)2021 09 26.
Article in English | MEDLINE | ID: covidwho-1438528

ABSTRACT

The coronavirus disease 2019 (COVID-19) is related to enhanced production of NETs, and autoimmune/autoinflammatory phenomena. We evaluated the proportion of low-density granulocytes (LDG) by flow cytometry, and their capacity to produce NETs was compared with that of conventional neutrophils. NETs and their protein cargo were quantified by confocal microscopy and ELISA. Antinuclear antibodies (ANA), anti-neutrophil cytoplasmic antibodies (ANCA) and the degradation capacity of NETs were addressed in serum. MILLIPLEX assay was used to assess the cytokine levels in macrophages' supernatant and serum. We found a higher proportion of LDG in severe and critical COVID-19 which correlated with severity and inflammatory markers. Severe/critical COVID-19 patients had higher plasmatic NE, LL-37 and HMGB1-DNA complexes, whilst ISG-15-DNA complexes were lower in severe patients. Sera from severe/critical COVID-19 patients had lower degradation capacity of NETs, which was reverted after adding hrDNase. Anti-NET antibodies were found in COVID-19, which correlated with ANA and ANCA positivity. NET stimuli enhanced the secretion of cytokines in macrophages. This study unveils the role of COVID-19 NETs as inducers of pro-inflammatory and autoimmune responses. The deficient degradation capacity of NETs may contribute to the accumulation of these structures and anti-NET antibodies are related to the presence of autoantibodies.


Subject(s)
Autoimmunity , COVID-19/blood , COVID-19/immunology , Extracellular Traps/immunology , Immunity, Humoral , Inflammation , Neutrophils/immunology , Antibodies, Antinuclear , Antimicrobial Cationic Peptides/blood , Autoantibodies/metabolism , Cross-Sectional Studies , Cytokines/metabolism , Cytokines/pharmacology , Flow Cytometry , Granulocytes/metabolism , HMGB1 Protein/blood , Healthy Volunteers , Humans , Microscopy, Confocal , Monocytes/cytology , Neutrophils/cytology , SARS-CoV-2 , Ubiquitins/pharmacology
11.
J Clin Invest ; 130(11): 6151-6157, 2020 11 02.
Article in English | MEDLINE | ID: covidwho-1435146

ABSTRACT

Emerging data indicate that complement and neutrophils contribute to the maladaptive immune response that fuels hyperinflammation and thrombotic microangiopathy, thereby increasing coronavirus 2019 (COVID-19) mortality. Here, we investigated how complement interacts with the platelet/neutrophil extracellular traps (NETs)/thrombin axis, using COVID-19 specimens, cell-based inhibition studies, and NET/human aortic endothelial cell (HAEC) cocultures. Increased plasma levels of NETs, tissue factor (TF) activity, and sC5b-9 were detected in patients. Neutrophils of patients yielded high TF expression and released NETs carrying active TF. Treatment of control neutrophils with COVID-19 platelet-rich plasma generated TF-bearing NETs that induced thrombotic activity of HAECs. Thrombin or NETosis inhibition or C5aR1 blockade attenuated platelet-mediated NET-driven thrombogenicity. COVID-19 serum induced complement activation in vitro, consistent with high complement activity in clinical samples. Complement C3 inhibition with compstatin Cp40 disrupted TF expression in neutrophils. In conclusion, we provide a mechanistic basis for a pivotal role of complement and NETs in COVID-19 immunothrombosis. This study supports strategies against severe acute respiratory syndrome coronavirus 2 that exploit complement or NETosis inhibition.


Subject(s)
Betacoronavirus , Complement Membrane Attack Complex , Coronavirus Infections , Extracellular Traps , Neutrophils , Pandemics , Pneumonia, Viral , Thromboplastin , Thrombosis , Aged , Betacoronavirus/immunology , Betacoronavirus/metabolism , COVID-19 , Complement Activation/drug effects , Complement Membrane Attack Complex/immunology , Complement Membrane Attack Complex/metabolism , Coronavirus Infections/blood , Coronavirus Infections/immunology , Extracellular Traps/immunology , Extracellular Traps/metabolism , Female , Humans , Male , Middle Aged , Neutrophils/immunology , Neutrophils/metabolism , Peptides, Cyclic/pharmacology , Pneumonia, Viral/blood , Pneumonia, Viral/immunology , Receptor, Anaphylatoxin C5a/antagonists & inhibitors , Receptor, Anaphylatoxin C5a/blood , Receptor, Anaphylatoxin C5a/immunology , Respiratory Distress Syndrome/blood , Respiratory Distress Syndrome/immunology , Respiratory Distress Syndrome/virology , SARS-CoV-2 , Thrombin/immunology , Thrombin/metabolism , Thromboplastin/immunology , Thromboplastin/metabolism , Thrombosis/blood , Thrombosis/immunology , Thrombosis/virology
12.
Med Hypotheses ; 156: 110684, 2021 Nov.
Article in English | MEDLINE | ID: covidwho-1415656

ABSTRACT

Some of the COVID-19 patients present with ischemic lesions of their finger and toes. Standard anticoagulant therapy is usually unsuccessful for the treatment of this unique presentation of COVID-19. In this review current evidence is presented, which supports the hypothesis that these necrotic lesions are primarily related to the formation of neutrophil extracellular traps is blood vessels. Also, currently available and potential pharmacological methods of the management of this unique thrombotic complication are discussed. Drugs that possibly could be used in COVID-19 patients suffering from acute ischemia of distal parts of the extremities particularly comprise DNase I and DNase1L3, which could directly dissolve these extracellular webs that are mostly composed of DNA. However, at the moment, none of these enzymes are registered for an intravascular administration in humans. Lactoferrin and dipyridamole are other pharmaceutical agents that could potentially be used for the treatment of neutrophil extracellular traps-evoked digital ischemia. These agents exhibit prophylactic activity against excessive formation of these extracellular structures. Such an experimental treatment should probably be accompanied by standard antithrombotic management with heparin. Open-label and then randomized trials are needed to confirm feasibility, safety and efficacy of the above-suggested management of critically ill COVID-19 patients.


Subject(s)
COVID-19 , Extracellular Traps , Thrombosis , Humans , Necrosis , Neutrophils , SARS-CoV-2 , Thrombosis/drug therapy
13.
JCI Insight ; 6(17)2021 09 08.
Article in English | MEDLINE | ID: covidwho-1413722

ABSTRACT

Neutrophil-mediated activation and injury of the endothelium play roles in the pathogenesis of diverse disease states ranging from autoimmunity to cancer to COVID-19. Neutralization of cationic proteins (such as neutrophil extracellular trap-derived [NET-derived] histones) with polyanionic compounds has been suggested as a potential strategy for protecting the endothelium from such insults. Here, we report that the US Food and Drug Administration-approved polyanionic agent defibrotide (a pleiotropic mixture of oligonucleotides) directly engages histones and thereby blocks their pathological effects on endothelium. In vitro, defibrotide counteracted endothelial cell activation and pyroptosis-mediated cell death, whether triggered by purified NETs or recombinant histone H4. In vivo, defibrotide stabilized the endothelium and protected against histone-accelerated inferior vena cava thrombosis in mice. Mechanistically, defibrotide demonstrated direct and tight binding to histone H4 as detected by both electrophoretic mobility shift assay and surface plasmon resonance. Taken together, these data provide insights into the potential role of polyanionic compounds in protecting the endothelium from thromboinflammation with potential implications for myriad NET- and histone-accelerated disease states.


Subject(s)
Fibrinolytic Agents/pharmacology , Human Umbilical Vein Endothelial Cells/drug effects , Polydeoxyribonucleotides/pharmacology , Thrombosis/drug therapy , Animals , Extracellular Traps/drug effects , Extracellular Traps/metabolism , Fibrinolytic Agents/therapeutic use , Histones/metabolism , Human Umbilical Vein Endothelial Cells/metabolism , Humans , Male , Mice , Mice, Inbred C57BL , Polydeoxyribonucleotides/therapeutic use , Pyroptosis
14.
Cells ; 10(7)2021 07 04.
Article in English | MEDLINE | ID: covidwho-1394870

ABSTRACT

Neutrophil extracellular traps (NETs) are web-like structures of decondensed extracellular chromatin fibers and neutrophil granule proteins released by neutrophils. NETs participate in host immune defense by entrapping pathogens. They are pro-inflammatory in function, and they act as an initiator of vascular coagulopathies by providing a platform for the attachment of various coagulatory proteins. NETs are diverse in their ability to alter physiological and pathological processes including infection and inflammation. In this review, we will summarize recent findings on the role of NETs in bacterial/viral infections associated with vascular inflammation, thrombosis, atherosclerosis and autoimmune disorders. Understanding the complex role of NETs in bridging infection and chronic inflammation as well as discussing important questions related to their contribution to pathologies outlined above may pave the way for future research on therapeutic targeting of NETs applicable to specific infections and inflammatory disorders.


Subject(s)
Cardiovascular System/pathology , Extracellular Traps/metabolism , Infections/pathology , Inflammation/pathology , Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis/pathology , Humans , Infections/virology , Models, Biological
15.
Int J Med Sci ; 18(3): 846-851, 2021.
Article in English | MEDLINE | ID: covidwho-1389719

ABSTRACT

In the last 50 years we have experienced two big pandemics, the HIV pandemic and the pandemic caused by SARS-CoV-2. Both pandemics are caused by RNA viruses and have reached us from animals. These two viruses are different in the transmission mode and in the symptoms they generate. However, they have important similarities: the fear in the population, increase in proinflammatory cytokines that generate intestinal microbiota modifications or NETosis production by polymorphonuclear neutrophils, among others. They have been implicated in the clinical, prognostic and therapeutic attitudes.


Subject(s)
COVID-19/epidemiology , HIV Infections/epidemiology , HIV-1/pathogenicity , Pandemics/history , SARS-CoV-2/pathogenicity , COVID-19/immunology , COVID-19/psychology , COVID-19/transmission , Cytokines/blood , Cytokines/immunology , Extracellular Traps/immunology , Extracellular Traps/metabolism , Fear , Global Burden of Disease/statistics & numerical data , HIV Infections/immunology , HIV Infections/psychology , HIV Infections/transmission , HIV-1/immunology , HIV-1/isolation & purification , History, 20th Century , History, 21st Century , Host-Pathogen Interactions/immunology , Humans , Inflammation Mediators/blood , Inflammation Mediators/immunology , Mortality , Neutrophils/immunology , Neutrophils/metabolism , Pandemics/statistics & numerical data , Prognosis , SARS-CoV-2/immunology , SARS-CoV-2/isolation & purification
16.
Int J Mol Sci ; 22(2)2021 Jan 08.
Article in English | MEDLINE | ID: covidwho-1389386

ABSTRACT

Neutrophils are primary effector cells of innate immunity and fight infection by phagocytosis and degranulation. Activated neutrophils also release neutrophil extracellular traps (NETs) in response to a variety of stimuli. These NETs are net-like complexes composed of cell-free DNA, histones and neutrophil granule proteins. Besides the evolutionarily conserved mechanism to capture and eliminate pathogens, NETs are also associated with pathophysiological processes of various diseases. Here, we elucidate the mechanisms of NET formation and their different implications in disease. We focused on autoinflammatory and cardiovascular disorders as the leading cause of death. Neutrophil extracellular traps are not only present in various cardiovascular diseases but play an essential role in atherosclerotic plaque formation, arterial and venous thrombosis, as well as in the development and progression of abdominal aortic aneurysms. Furthermore, NETosis can be considered as a source of autoantigens and maintains an inflammatory milieu promoting autoimmune diseases. Indeed, there is further need for research into the balance between NET induction, inhibition, and degradation in order to pharmacologically target NETs and their compounds without impairing the patient's immune defense. This review may be of interest to both basic scientists and clinicians to stimulate translational research and innovative clinical approaches.


Subject(s)
Autoimmune Diseases/immunology , Extracellular Traps/immunology , Neutrophils/immunology , Aortic Aneurysm, Abdominal/pathology , Autoimmune Diseases/pathology , Autoimmunity/immunology , COVID-19/immunology , COVID-19/pathology , Humans , Neutrophil Activation/immunology , Plaque, Atherosclerotic/pathology , Thrombosis/pathology
17.
Immun Inflamm Dis ; 9(4): 1186-1196, 2021 12.
Article in English | MEDLINE | ID: covidwho-1384181

ABSTRACT

Neutrophils play multiple roles in acute viral infections. They restrict viral replication and diffusion through phagocytosis, degranulation, respiratory burst, secretion of cytokines, and the release of neutrophil extracellular traps, as well as, activate the adaptive immune response. However, the overactivation of neutrophils may cause tissue damage and lead to poor outcomes. Additionally, some characteristics and functions of neutrophils, such as cell number, lifespan, and antiviral capability, can be influenced while eliminating viruses. This review provides a general description of the protective and pathological roles of neutrophils in acute viral infection.


Subject(s)
Extracellular Traps , Virus Diseases , Adaptive Immunity , Humans , Neutrophils , Phagocytosis
19.
Int J Mol Sci ; 22(16)2021 Aug 17.
Article in English | MEDLINE | ID: covidwho-1360774

ABSTRACT

Neutrophil extracellular traps (NETs), built from mitochondrial or nuclear DNA, proteinases, and histones, entrap and eliminate pathogens in the course of bacterial or viral infections. Neutrophils' activation and the formation of NETs have been described as major risk factors for acute lung injury, multi-organ damage, and mortality in COVID-19 disease. NETs-related lung injury involves both epithelial and endothelial cells, as well as the alveolar-capillary barrier. The markers for NETs formation, such as circulating DNA, neutrophil elastase (NE) activity, or myeloperoxidase-DNA complexes, were found in lung specimens of COVID-19 victims, as well as in sera and tracheal aspirates obtained from COVID-19 patients. DNA threads form large conglomerates causing local obstruction of the small bronchi and together with NE are responsible for overproduction of mucin by epithelial cells. Various components of NETs are involved in the pathogenesis of cytokine storm in SARS-CoV-2 pulmonary disease. NETs are responsible for the interplay between inflammation and thrombosis in the affected lungs. The immunothrombosis, stimulated by NETs, has a poor prognostic significance. Better understanding of the role of NETs in the course of COVID-19 can help to develop novel approaches to the therapeutic interventions in this condition.


Subject(s)
COVID-19/immunology , Extracellular Traps/virology , Lung/immunology , Neutrophils/immunology , SARS-CoV-2/immunology , COVID-19/pathology , COVID-19/virology , Cytokine Release Syndrome/immunology , Cytokine Release Syndrome/virology , Endothelial Cells/pathology , Epithelial Cells/pathology , Extracellular Traps/immunology , Histones/immunology , Humans , Leukocyte Elastase/deficiency , Leukocyte Elastase/immunology , Lung/pathology , Lung/virology , Neutrophil Activation , Neutrophils/virology , Peroxidase/immunology
20.
J Drugs Dermatol ; 20(8): 868-873, 2021 Aug 01.
Article in English | MEDLINE | ID: covidwho-1359537

ABSTRACT

The Symposium on Hidradenitis Suppurativa Advances (SHSA) is a joint meeting of the United States Hidradenitis Suppurativa Foundation (HSF) and the Canadian Hidradenitis Suppurativa Foundation (CHSF). This annual cross-disciplinary meeting brings together experts from around the world in an opportunity to discuss the most recent advances in the study of hidradenitis suppurativa (HS). The fifth annual meeting was held virtually on 9-11 October 2020. A record 347 attendees, including 79 people with HS, from 20 different countries attended. Key take-home points included: Clinicians can optimize each visit by listening, provide education, and discuss treatments; a patient decision aid for HS (HS-PDA) is a freely available tool (www.informed-decisions.org); COVID-19 severity in HS patients was not different for patients treated with/without a biologic; comorbidity screening recommendations will be published soon; neutrophil extracellular traps (NETs) may play a role in HS; memory B cells, T helper 1 cytokines, and interleukin 1 signaling contributes to HS pathogenesis and are targets for new therapies; novel therapies are showing promise including a new JAK1 inhibitor (INCB054707) and brodalumab; and HS-specific outcome measures have emerged to better monitor disease severity, flare, and progression including a patient reported measure (HiSQOL) and an HS-specific investigator global assessment. J Drugs Dermatol. 2021;20(8):868-873. doi:10.36849/JDD.5836.


Subject(s)
Hidradenitis Suppurativa , COVID-19 , Canada , Comorbidity , Congresses as Topic , Cytokines , Decision Support Techniques , Disease Progression , Extracellular Traps , Hidradenitis Suppurativa/diagnosis , Hidradenitis Suppurativa/therapy , Humans , Patient Reported Outcome Measures , Severity of Illness Index
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