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1.
Int J Mol Sci ; 23(7)2022 Mar 31.
Article in English | MEDLINE | ID: covidwho-1776246

ABSTRACT

There is accumulating evidence that platelets play roles beyond their traditional functions in thrombosis and hemostasis, e.g., in inflammatory processes, infection and cancer, and that they interact, stimulate and regulate cells of the innate immune system such as neutrophils, monocytes and macrophages. In this review, we will focus on platelet activation in hemostatic and inflammatory processes, as well as platelet interactions with neutrophils and monocytes/macrophages. We take a closer look at the contributions of major platelet receptors GPIb, αIIbß3, TLT-1, CLEC-2 and Toll-like receptors (TLRs) as well as secretions from platelet granules on platelet-neutrophil aggregate and neutrophil extracellular trap (NET) formation in atherosclerosis, transfusion-related acute lung injury (TRALI) and COVID-19. Further, we will address platelet-monocyte and macrophage interactions during cancer metastasis, infection, sepsis and platelet clearance.


Subject(s)
COVID-19 , Thrombosis , Blood Platelets/pathology , Hemostasis , Humans , Immunity, Innate , Inflammation/pathology , Neutrophils/pathology , Platelet Activation , Thrombosis/pathology
2.
Biochem J ; 479(5): 609-628, 2022 03 18.
Article in English | MEDLINE | ID: covidwho-1730329

ABSTRACT

Two years after the emergence of SARS-CoV-2, our understanding of COVID-19 disease pathogenesis is still incomplete. Despite unprecedented global collaborative scientific efforts and rapid vaccine development, an uneven vaccine roll-out and the emergence of novel variants of concern such as omicron underscore the critical importance of identifying the mechanisms that contribute to this disease. Overt inflammation and cell death have been proposed to be central drivers of severe pathology in COVID-19 patients and their pathways and molecular components therefore present promising targets for host-directed therapeutics. In our review, we summarize the current knowledge on the role and impact of diverse programmed cell death (PCD) pathways on COVID-19 disease. We dissect the complex connection of cell death and inflammatory signaling at the cellular and molecular level and identify a number of critical questions that remain to be addressed. We provide rationale for targeting of cell death as potential COVID-19 treatment and provide an overview of current therapeutics that could potentially enter clinical trials in the near future.


Subject(s)
COVID-19/etiology , COVID-19/pathology , Antiviral Agents , Apoptosis/drug effects , Apoptosis/physiology , COVID-19/drug therapy , Humans , Inflammasomes/physiology , Interferons/metabolism , Necroptosis/physiology , Neutrophils/pathology , Neutrophils/virology , Pyroptosis/physiology , SARS-CoV-2/pathogenicity
3.
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
4.
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
5.
Dis Markers ; 2021: 6304189, 2021.
Article in English | MEDLINE | ID: covidwho-1553755

ABSTRACT

Background: Early identification of patients with severe coronavirus disease (COVID-19) at an increased risk of progression may promote more individualized treatment schemes and optimize the use of medical resources. This study is aimed at investigating the utility of the C-reactive protein to albumin (CRP/Alb) ratio for early risk stratification of patients. Methods: We retrospectively reviewed 557 patients with COVID-19 with confirmed outcomes (discharged or deceased) admitted to the West Court of Union Hospital, Wuhan, China, between January 29, 2020 and April 8, 2020. Patients with severe COVID-19 (n = 465) were divided into stable (n = 409) and progressive (n = 56) groups according to whether they progressed to critical illness or death during hospitalization. To predict disease progression, the CRP/Alb ratio was evaluated on admission. Results: The levels of new biomarkers, including neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, CRP/Alb ratio, and systemic immune-inflammation index, were higher in patients with progressive disease than in those with stable disease. Correlation analysis showed that the CRP/Alb ratio had the strongest positive correlation with the sequential organ failure assessment score and length of hospital stay in survivors. Multivariate logistic regression analysis showed that percutaneous oxygen saturation (SpO2), D-dimer levels, and the CRP/Alb ratio were risk factors for disease progression. To predict clinical progression, the areas under the receiver operating characteristic curves of Alb, CRP, CRP/Alb ratio, SpO2, and D-dimer were 0.769, 0.838, 0.866, 0.107, and 0.748, respectively. Moreover, patients with a high CRP/Alb ratio (≥1.843) had a markedly higher rate of clinical deterioration (log - rank p < 0.001). A higher CRP/Alb ratio (≥1.843) was also closely associated with higher rates of hospital mortality, ICU admission, invasive mechanical ventilation, and a longer hospital stay. Conclusion: The CRP/Alb ratio can predict the risk of progression to critical disease or death early, providing a promising prognostic biomarker for risk stratification and clinical management of patients with severe COVID-19.


Subject(s)
C-Reactive Protein/metabolism , COVID-19/diagnosis , Coronary Disease/diagnosis , Hypertension/diagnosis , Pulmonary Disease, Chronic Obstructive/diagnosis , SARS-CoV-2/pathogenicity , Serum Albumin, Human/metabolism , Aged , Area Under Curve , Biomarkers/blood , Blood Platelets/pathology , Blood Platelets/virology , COVID-19/epidemiology , COVID-19/mortality , COVID-19/virology , China/epidemiology , Comorbidity , Coronary Disease/epidemiology , Coronary Disease/mortality , Coronary Disease/virology , Disease Progression , Early Diagnosis , Female , Fibrin Fibrinogen Degradation Products/metabolism , Humans , Hypertension/epidemiology , Hypertension/mortality , Hypertension/virology , Length of Stay/statistics & numerical data , Lymphocytes/pathology , Lymphocytes/virology , Male , Middle Aged , Neutrophils/pathology , Neutrophils/virology , Prognosis , Pulmonary Disease, Chronic Obstructive/epidemiology , Pulmonary Disease, Chronic Obstructive/mortality , Pulmonary Disease, Chronic Obstructive/virology , ROC Curve , Retrospective Studies , SARS-CoV-2/growth & development , Severity of Illness Index , Survival Analysis
6.
Cells ; 10(11)2021 11 12.
Article in English | MEDLINE | ID: covidwho-1526806

ABSTRACT

Aging affects all tissues and organs. Aging of the immune system results in the severe disruption of its functions, leading to an increased susceptibility to infections, an increase in autoimmune disorders and cancer incidence, and a decreased response to vaccines. Lymph nodes are precisely organized structures of the peripheral lymphoid organs and are the key sites coordinating innate and long-term adaptive immune responses to external antigens and vaccines. They are also involved in immune tolerance. The aging of lymph nodes results in decreased cell transport to and within the nodes, a disturbance in the structure and organization of nodal zones, incorrect location of individual immune cell types and impaired intercellular interactions, as well as changes in the production of adequate amounts of chemokines and cytokines necessary for immune cell proliferation, survival and function, impaired naïve T- and B-cell homeostasis, and a diminished long-term humoral response. Understanding the causes of these stromal and lymphoid microenvironment changes in the lymph nodes that cause the aging-related dysfunction of the immune system can help to improve long-term immune responses and the effectiveness of vaccines in the elderly.


Subject(s)
Aging/pathology , Immunosenescence , Lymph Nodes/pathology , Lymph Nodes/physiopathology , Animals , Cellular Microenvironment , Humans , Models, Biological , Neutrophils/pathology
7.
Med Oncol ; 39(1): 6, 2021 Nov 08.
Article in English | MEDLINE | ID: covidwho-1506526

ABSTRACT

To assess the prognostic role of different inflammatory indices on the outcome of cancer patients with COVID-19. Sixty-two adults and 22 pediatric cancer patients with COVID-19 infection were assessed for the prognostic value of certain inflammatory indices including the neutrophil to lymphocyte ratio (NLR), monocyte to lymphocyte ratio (MLR), platelet to lymphocyte ratio (PLR), derived NLR (dNLR), systemic inflammation index (SII), mean platelet volume to platelet ratio (MPR), C-reactive protein to lymphocyte ratio (CRP/L), aggregate index of systemic inflammation (AISI), systemic inflammation response index (SIRI), and neutrophil to lymphocyte, platelet ratio (NLPR). Data were correlated to patients' outcome regarding ICU admission, and incidence of mortality. Increased CRP/L ratio in adult COVID-19 cancer patients was significantly associated with inferior survival [152 (19-2253) in non-survivors, compared to 27.4 (0.8-681) in survivors (P = 0.033)]. It achieved a sensitivity (60%) and a specificity (90.2%) at a cut-off 152, while it achieved a sensitivity of 60% and specificity 95.1% at a cut-off 252 (AUC 0.795, P = 0.033). When combining both CRP/L and NLPR for the prediction of poor outcome in adult cancer patients with COVID19, the sensitivity increased to 80% and the specificity was 70.7% (AUC 0.805, P = 0.027). Increased incidence of ICU admission in pediatric cancer patients associated significantly with the severity of covid19 infection, decreased mean corpuscular hemoglobin (MCH) < 28.3, increased red cell distribution width (RDW) > 16, lymphopenia < 1.04, pseudo Pelger-Huet appearance, and PLR < 196.4 (P = 0.004, P = 0.040, P = 0.029, P = 0. 0.039, P = 0.050, and P = 0.040; respectively). The mean corpuscular volume (MCV), MCH, and RDW could be useful prognostic markers for poor outcome in COVID-19 pediatric cancer patients (P < 0.05 for all). Increased both CRP/L and NLPR associated significantly with poor survival in adult COVID-19 cancer patients, while PLR associated significantly with ICU admission in pediatric COVID-19 cancer patients.


Subject(s)
COVID-19/pathology , Inflammation/pathology , Neoplasms/pathology , Adolescent , Adult , Aged , Blood Platelets/pathology , Child , Child, Preschool , Female , Humans , Inflammation/virology , Leukocyte Count/methods , Lymphocytes/pathology , Male , Middle Aged , Neoplasms/virology , Neutrophils/pathology , Prognosis , Retrospective Studies , SARS-CoV-2/pathogenicity , Sensitivity and Specificity , Young Adult
8.
Am J Pathol ; 192(1): 112-120, 2022 01.
Article in English | MEDLINE | ID: covidwho-1506166

ABSTRACT

Severe coronavirus disease 2019 (COVID-19) increases the risk of myocardial injury that contributes to mortality. This study used multiparameter immunofluorescence to extensively examine heart autopsy tissue of 7 patients who died of COVID-19 compared to 12 control specimens, with or without cardiovascular disease. Consistent with prior reports, no evidence of viral infection or lymphocytic infiltration indicative of myocarditis was found. However, frequent and extensive thrombosis was observed in large and small vessels in the hearts of the COVID-19 cohort, findings that were infrequent in controls. The endothelial lining of thrombosed vessels typically lacked evidence of cytokine-mediated endothelial activation, assessed as nuclear expression of transcription factors p65 (RelA), pSTAT1, or pSTAT3, or evidence of inflammatory activation assessed by expression of intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), tissue factor, or von Willebrand factor (VWF). Intimal EC lining was also generally preserved with little evidence of cell death or desquamation. In contrast, there were frequent markers of neutrophil activation within myocardial thrombi in patients with COVID-19, including neutrophil-platelet aggregates, neutrophil-rich clusters within macrothrombi, and evidence of neutrophil extracellular trap (NET) formation. These findings point to alterations in circulating neutrophils rather than in the endothelium as contributors to the increased thrombotic diathesis in the hearts of COVID-19 patients.


Subject(s)
COVID-19 , Coronary Vessels , Myocarditis , Myocardium , SARS-CoV-2/metabolism , Thrombosis , Aged , Aged, 80 and over , Blood Platelets/metabolism , Blood Platelets/pathology , COVID-19/metabolism , COVID-19/pathology , Coronary Vessels/metabolism , Coronary Vessels/pathology , Endothelium, Vascular/metabolism , Endothelium, Vascular/pathology , Female , Gene Expression Regulation , Humans , Male , Middle Aged , Myocarditis/metabolism , Myocarditis/pathology , Myocardium/metabolism , Myocardium/pathology , Neutrophil Activation , Neutrophils/metabolism , Neutrophils/pathology , Platelet Aggregation , Thrombosis/metabolism , Thrombosis/pathology
9.
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
10.
Mol Med ; 27(1): 129, 2021 10 18.
Article in English | MEDLINE | ID: covidwho-1477255

ABSTRACT

BACKGROUND: Host inflammation contributes to determine whether SARS-CoV-2 infection causes mild or life-threatening disease. Tools are needed for early risk assessment. METHODS: We studied in 111 COVID-19 patients prospectively followed at a single reference Hospital fifty-three potential biomarkers including alarmins, cytokines, adipocytokines and growth factors, humoral innate immune and neuroendocrine molecules and regulators of iron metabolism. Biomarkers at hospital admission together with age, degree of hypoxia, neutrophil to lymphocyte ratio (NLR), lactate dehydrogenase (LDH), C-reactive protein (CRP) and creatinine were analysed within a data-driven approach to classify patients with respect to survival and ICU outcomes. Classification and regression tree (CART) models were used to identify prognostic biomarkers. RESULTS: Among the fifty-three potential biomarkers, the classification tree analysis selected CXCL10 at hospital admission, in combination with NLR and time from onset, as the best predictor of ICU transfer (AUC [95% CI] = 0.8374 [0.6233-0.8435]), while it was selected alone to predict death (AUC [95% CI] = 0.7334 [0.7547-0.9201]). CXCL10 concentration abated in COVID-19 survivors after healing and discharge from the hospital. CONCLUSIONS: CXCL10 results from a data-driven analysis, that accounts for presence of confounding factors, as the most robust predictive biomarker of patient outcome in COVID-19.


Subject(s)
COVID-19/diagnosis , Chemokine CXCL10/blood , Coronary Artery Disease/diagnosis , Diabetes Mellitus/diagnosis , Hypertension/diagnosis , Biomarkers/blood , C-Reactive Protein/metabolism , COVID-19/blood , COVID-19/immunology , COVID-19/mortality , Comorbidity , Coronary Artery Disease/blood , Coronary Artery Disease/immunology , Coronary Artery Disease/mortality , Creatine/blood , Diabetes Mellitus/blood , Diabetes Mellitus/immunology , Diabetes Mellitus/mortality , Female , Hospitalization , Humans , Hypertension/blood , Hypertension/immunology , Hypertension/mortality , Immunity, Humoral , Immunity, Innate , Inflammation , Intensive Care Units , L-Lactate Dehydrogenase/blood , Leukocyte Count , Lymphocytes/immunology , Lymphocytes/pathology , Male , Middle Aged , Neutrophils/immunology , Neutrophils/pathology , Prognosis , Prospective Studies , Retrospective Studies , SARS-CoV-2 , Severity of Illness Index , Survival Analysis
11.
J Clin Invest ; 131(20)2021 10 15.
Article in English | MEDLINE | ID: covidwho-1470547

ABSTRACT

BACKGROUNDMultisystem inflammatory syndrome in children (MIS-C) is a rare but potentially severe illness that follows exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Kawasaki disease (KD) shares several clinical features with MIS-C, which prompted the use of intravenous immunoglobulin (IVIG), a mainstay therapy for KD. Both diseases share a robust activation of the innate immune system, including the IL-1 signaling pathway, and IL-1 blockade has been used for the treatment of both MIS-C and KD. The mechanism of action of IVIG in these 2 diseases and the cellular source of IL-1ß have not been defined.METHODSThe effects of IVIG on peripheral blood leukocyte populations from patients with MIS-C and KD were examined using flow cytometry and mass cytometry (CyTOF) and live-cell imaging.RESULTSCirculating neutrophils were highly activated in patients with KD and MIS-C and were a major source of IL-1ß. Following IVIG treatment, activated IL-1ß+ neutrophils were reduced in the circulation. In vitro, IVIG was a potent activator of neutrophil cell death via PI3K and NADPH oxidase, but independently of caspase activation.CONCLUSIONSActivated neutrophils expressing IL-1ß can be targeted by IVIG, supporting its use in both KD and MIS-C to ameliorate inflammation.FUNDINGPatient Centered Outcomes Research Institute; NIH; American Asthma Foundation; American Heart Association; Novo Nordisk Foundation; NIGMS; American Academy of Allergy, Asthma and Immunology Foundation.


Subject(s)
COVID-19/complications , Immunoglobulins, Intravenous/therapeutic use , Mucocutaneous Lymph Node Syndrome/immunology , Mucocutaneous Lymph Node Syndrome/therapy , Systemic Inflammatory Response Syndrome/immunology , Systemic Inflammatory Response Syndrome/therapy , COVID-19/blood , COVID-19/immunology , COVID-19/therapy , Case-Control Studies , Cell Death/immunology , Cell Lineage/immunology , Child , Child, Preschool , Fas Ligand Protein/immunology , Female , Humans , Infant , Interleukin-1beta/antagonists & inhibitors , Interleukin-1beta/blood , Leukocyte Count , Male , Mucocutaneous Lymph Node Syndrome/blood , Neutrophil Activation , Neutrophils/classification , Neutrophils/immunology , Neutrophils/pathology , Systemic Inflammatory Response Syndrome/blood
12.
Cells ; 10(9)2021 09 13.
Article in English | MEDLINE | ID: covidwho-1468387

ABSTRACT

Neutrophils are key cells of the innate immune system. It is now understood that this leukocyte population is diverse in both the basal composition and functional plasticity. Underlying this plasticity is a post-translational framework for rapidly achieving early activation states, but also a transcriptional capacity that is becoming increasingly recognized by immunologists. Growing interest in the contribution of neutrophils to health and disease has resulted in more efforts to describe their transcriptional activity. Whilst initial efforts focused predominantly on understanding the existing biology, investigations with advanced methods such as single cell RNA sequencing to understand interactions of the entire immune system are revealing higher flexibility in neutrophil transcription than previously thought possible and multiple transition states. It is now apparent that neutrophils utilise many forms of RNA in the regulation of their function. This review collates current knowledge on the nuclei structure and gene expression activity of human neutrophils across homeostasis and disease, before highlighting knowledge gaps that are research priority areas.


Subject(s)
Disease/etiology , Gene Expression Regulation , Immunity, Innate/immunology , Neutrophils/immunology , Neutrophils/pathology , Transcriptome , Animals , Homeostasis , Humans , Neutrophils/metabolism , Signal Transduction
13.
Dis Markers ; 2021: 6803510, 2021.
Article in English | MEDLINE | ID: covidwho-1443673

ABSTRACT

Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is currently the most significant public health threat worldwide. Patients with severe COVID-19 usually have pneumonia concomitant with local inflammation and sometimes a cytokine storm. Specific components of the SARS-CoV-2 virus trigger lung inflammation, and recruitment of immune cells to the lungs exacerbates this process, although much remains unknown about the pathogenesis of COVID-19. Our study of lung type II pneumocyte cells (A549) demonstrated that ORF7, an open reading frame (ORF) in the genome of SARS-CoV-2, induced the production of CCL2, a chemokine that promotes the chemotaxis of monocytes, and decreased the expression of IL-8, a chemokine that recruits neutrophils. A549 cells also had an increased level of IL-6. The results of our chemotaxis Transwell assay suggested that ORF7 augmented monocyte infiltration and reduced the number of neutrophils. We conclude that the ORF7 of SARS-CoV-2 may have specific effects on the immunological changes in tissues after infection. These results suggest that the functions of other ORFs of SARS-CoV-2 should also be comprehensively examined.


Subject(s)
COVID-19/metabolism , Chemotaxis , Monocytes/pathology , Neutrophils/pathology , Open Reading Frames/physiology , Pneumonia/pathology , Viral Proteins/metabolism , A549 Cells , Chemokine CCL2/metabolism , Humans , In Vitro Techniques , Monocytes/immunology , Monocytes/metabolism , Neutrophils/immunology , Neutrophils/metabolism , Pneumonia/immunology , Pneumonia/metabolism , SARS-CoV-2/metabolism , Viral Proteins/genetics
14.
Front Immunol ; 12: 717461, 2021.
Article in English | MEDLINE | ID: covidwho-1435990

ABSTRACT

Data on the impact of lymphocytes and neutrophils on the incidence of liver dysfunction in COVID-19 patients are limited. This study aimed to investigate the lateral and longitudinal associations of lymphocyte ratio (LR) and neutrophil ratio (NR) on liver dysfunction in COVID-19 patients. We tested 1,409 blood samples from 245 COVID-19 patients in China between January 2020 and June 2021. The lateral U-shaped relationships, determined by smooth curve fitting and the piecewise-linear mixed-effect model, were observed between LR, NR, and AST and the incidence of AST-linked liver dysfunction, with the threshold cutoffs of 26.1 and 62.0, respectively. Over the 1,409 tests, the LR ≤ 26.1 and NR ≥ 62.0 related to the occurrence of mild liver dysfunction (HR: 1.36; 95% CI: 1.01, 1.82), moderate liver dysfunction (HR: 1.37; 95% CI: 1.01, 1.85), and severe liver dysfunction (HR: 1.72; 95% CI: 1.02, 2.90). For the patients with preexisting AST ≥ 35 U/L, the baseline LR ≤ 26.1 and NR ≥ 62.0 (b.LLCHN) groups had a fully adjusted 8.85-, 7.88-, and 5.97-fold increased risk of mild and moderate liver dysfunction after being hospitalized of 3, 6, and 9 days compared to the baseline LR > 26.1 and NR < 62.0 (b.normal) groups. Severe liver dysfunction only presents significant differences after being adjusted for age, sex, and BMI. Consistently, Kaplan-Meier analyses showed that b.LLCHN reflects a better predictive value for different subsequent magnitude liver dysfunctions after admission of 3 and 6 days. To improve liver function in patients with preexisting AST ≥35 U/L, future management strategies should pay more attention to baseline LR ≤ 26.1 and NR ≥ 62.0 patients.


Subject(s)
COVID-19/physiopathology , Liver/physiopathology , Lymphocytes/pathology , Neutrophils/pathology , Adult , Aspartate Aminotransferases/blood , Biomarkers/blood , COVID-19/blood , China/epidemiology , Female , Humans , Leukocyte Count , Longitudinal Studies , Male , Middle Aged , Proportional Hazards Models , SARS-CoV-2
15.
JCI Insight ; 6(18)2021 09 22.
Article in English | MEDLINE | ID: covidwho-1435144

ABSTRACT

Neutrophils provide a critical line of defense in immune responses to various pathogens, inflicting self-damage upon transition to a hyperactivated, procoagulant state. Recent work has highlighted proinflammatory neutrophil phenotypes contributing to lung injury and acute respiratory distress syndrome (ARDS) in patients with coronavirus disease 2019 (COVID-19). Here, we use state-of-the art mass spectrometry-based proteomics and transcriptomic and correlative analyses as well as functional in vitro and in vivo studies to dissect how neutrophils contribute to the progression to severe COVID-19. We identify a reinforcing loop of both systemic and neutrophil intrinsic IL-8 (CXCL8/IL-8) dysregulation, which initiates and perpetuates neutrophil-driven immunopathology. This positive feedback loop of systemic and neutrophil autocrine IL-8 production leads to an activated, prothrombotic neutrophil phenotype characterized by degranulation and neutrophil extracellular trap (NET) formation. In severe COVID-19, neutrophils directly initiate the coagulation and complement cascade, highlighting a link to the immunothrombotic state observed in these patients. Targeting the IL-8-CXCR-1/-2 axis interferes with this vicious cycle and attenuates neutrophil activation, degranulation, NETosis, and IL-8 release. Finally, we show that blocking IL-8-like signaling reduces severe acute respiratory distress syndrome of coronavirus 2 (SARS-CoV-2) spike protein-induced, human ACE2-dependent pulmonary microthrombosis in mice. In summary, our data provide comprehensive insights into the activation mechanisms of neutrophils in COVID-19 and uncover a self-sustaining neutrophil-IL-8 axis as a promising therapeutic target in severe SARS-CoV-2 infection.


Subject(s)
COVID-19/metabolism , Interleukin-8/metabolism , Lung/immunology , Neutrophils/immunology , SARS-CoV-2 , Thrombosis/etiology , Animals , COVID-19/complications , COVID-19/pathology , Humans , Lung/pathology , Mice , Neutrophil Activation , Neutrophils/pathology , Phenotype , Thrombosis/pathology
16.
Aging (Albany NY) ; 13(17): 20896-20905, 2021 09 08.
Article in English | MEDLINE | ID: covidwho-1399703

ABSTRACT

BACKGROUND: This study aimed to explore the significance of neutrophil-to-lymphocyte ratio (NLR), lactate dehydrogenase (LDH), D-dimer, and CT score in evaluating the severity and prognosis of coronavirus disease 2019 (COVID-19). METHODS: Patients with laboratory-confirmed COVID-19 were retrospectively enrolled. The baseline data, laboratory findings, chest computed tomography (CT) results evaluated by CT score on admission, and clinical outcomes were collected and compared. Logistic regression was used to assess the independent relationship between the baseline level of the four indicators (NLR, LDH, D-dimer, and CT score) and the severity of COVID-19. RESULTS: Among the 432 patients, 125 (28.94%) and 307 (71.06%) were placed in the severe and non-severe groups, respectively. As per the multivariate logistic regression, high levels of NLR and LDH were independent predictors of severe COVID-19 (OR=2.163; 95% CI=1.162-4.026; p=0.015 for NLR>3.82; OR=2.298; 95% CI=1.327-3.979; p=0.003 for LDH>246 U/L). Combined NLR>3.82 and LDH>246 U/L increased the sensitivity of diagnosis in patients with severe disease (NLR>3.82 [50.40%] vs. combined diagnosis [72.80%]; p=0.0007; LDH>246 [59.2%] vs. combined diagnosis [72.80%]; p<0.0001). CONCLUSIONS: High levels of serum NLR and LDH have potential value in the early identification of patients with severe COVID-19. Moreover, the combination of LDH and NLR can improve the sensitivity of diagnosis.


Subject(s)
COVID-19/blood , COVID-19/diagnostic imaging , Fibrin Fibrinogen Degradation Products/metabolism , L-Lactate Dehydrogenase/blood , Lymphocytes/pathology , Neutrophils/pathology , Tomography, X-Ray Computed , Female , Humans , Logistic Models , Male , Middle Aged , Multivariate Analysis , Prognosis , ROC Curve
17.
Cells ; 10(9)2021 09 06.
Article in English | MEDLINE | ID: covidwho-1390544

ABSTRACT

Studying the dynamics changes of neutrophils during innate immune response in coronavirus 2019 (COVID-19) can help understand the pathogenesis of this disease. The aim of the study was to assess the usefulness of new neutrophil activation parameters: Immature Granulocyte (IG), Neutrophil Reactivity Intensity (NEUT-RI), Neutrophil Granularity Intensity (NEUT-GI), and data relating to granularity, activity, and neutrophil volume (NE-WX, NE-WY, NE-WZ) available in hematology analyzers to distinguish convalescent patients from patients with active SARS-CoV-2 infection and healthy controls (HC). The study group consisted of 79 patients with a confirmed positive RT-PCR test for SARS-CoV2 infection, 71 convalescent patients, and 20 HC. We observed leukopenia with neutrophilia in patients with active infection compared to convalescents and HC. The IG median absolute count was higher in convalescent patients than in COVID-19 and HC (respectively, 0.08 vs. 0.03 vs. 0.02, p < 0.0001). The value of the NEUT-RI parameter was the highest in HC and the lowest in convalescents (48.3 vs. 43.7, p < 0.0001). We observed the highest proportion of NE-WX, NE-WY, and NE-WZ parameters in HC, without differences between the COVID-19 and convalescent groups. New neutrophil parameters can be useful tools to assess neutrophils' activity and functionalities in the immune response during infection and recovery from COVID-19 disease.


Subject(s)
COVID-19/pathology , Cell Differentiation , Convalescence , Neutrophils/pathology , Case-Control Studies , Female , Humans , Male , Middle Aged , Severity of Illness Index
19.
Nature ; 591(7848): 124-130, 2021 03.
Article in English | MEDLINE | ID: covidwho-1368933

ABSTRACT

Although infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has pleiotropic and systemic effects in some individuals1-3, many others experience milder symptoms. Here, to gain a more comprehensive understanding of the distinction between severe and mild phenotypes in the pathology of coronavirus disease 2019 (COVID-19) and its origins, we performed a whole-blood-preserving single-cell analysis protocol to integrate contributions from all major immune cell types of the blood-including neutrophils, monocytes, platelets, lymphocytes and the contents of the serum. Patients with mild COVID-19 exhibit a coordinated pattern of expression of interferon-stimulated genes (ISGs)3 across every cell population, whereas these ISG-expressing cells are systemically absent in patients with severe disease. Paradoxically, individuals with severe COVID-19 produce very high titres of anti-SARS-CoV-2 antibodies and have a lower viral load compared to individuals with mild disease. Examination of the serum from patients with severe COVID-19 shows that these patients uniquely produce antibodies that functionally block the production of the ISG-expressing cells associated with mild disease, by activating conserved signalling circuits that dampen cellular responses to interferons. Overzealous antibody responses pit the immune system against itself in many patients with COVID-19, and perhaps also in individuals with other viral infections. Our findings reveal potential targets for immunotherapies in patients with severe COVID-19 to re-engage viral defence.


Subject(s)
Antibodies, Viral/immunology , COVID-19/immunology , COVID-19/physiopathology , Interferons/antagonists & inhibitors , Interferons/immunology , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Antibodies, Viral/blood , Antibody Formation , Base Sequence , COVID-19/blood , COVID-19/virology , Female , Humans , Immunoglobulin G/immunology , Interferons/metabolism , Male , Neutrophils/immunology , Neutrophils/pathology , Protein Domains , Receptor, Interferon alpha-beta/antagonists & inhibitors , Receptor, Interferon alpha-beta/immunology , Receptor, Interferon alpha-beta/metabolism , Receptors, IgG/immunology , Single-Cell Analysis , Viral Load/immunology
20.
Front Immunol ; 12: 631821, 2021.
Article in English | MEDLINE | ID: covidwho-1344260

ABSTRACT

Neutrophils or polymorphonuclear leukocytes (PMN) are key participants in the innate immune response for their ability to execute different effector functions. These cells express a vast array of membrane receptors that allow them to recognize and eliminate infectious agents effectively and respond appropriately to microenvironmental stimuli that regulate neutrophil functions, such as activation, migration, generation of reactive oxygen species, formation of neutrophil extracellular traps, and mediator secretion, among others. Currently, it has been realized that activated neutrophils can accomplish their effector functions and simultaneously activate mechanisms of cell death in response to different intracellular or extracellular factors. Although several studies have revealed similarities between the mechanisms of cell death of neutrophils and other cell types, neutrophils have distinctive properties, such as a high production of reactive oxygen species (ROS) and nitrogen species (RNS), that are important for their effector function in infections and pathologies such as cancer, autoimmune diseases, and immunodeficiencies, influencing their cell death mechanisms. The present work offers a synthesis of the conditions and molecules implicated in the regulation and activation of the processes of neutrophil death: apoptosis, autophagy, pyroptosis, necroptosis, NETosis, and necrosis. This information allows to understand the duality encountered by PMNs upon activation. The effector functions are carried out to eliminate invading pathogens, but in several instances, these functions involve activation of signaling cascades that culminate in the death of the neutrophil. This process guarantees the correct elimination of pathogenic agents, damaged or senescent cells, and the timely resolution of the inflammation that is essential for the maintenance of homeostasis in the organism. In addition, they alert the organism when the immunological system is being deregulated, promoting the activation of other cells of the immune system, such as B and T lymphocytes, which produce cytokines that potentiate the microbicide functions.


Subject(s)
Cell Death/immunology , Neutrophils/pathology , Apoptosis/immunology , Apoptosis Regulatory Proteins/metabolism , Autophagy/immunology , Extracellular Traps/immunology , Extracellular Traps/metabolism , Free Radicals/metabolism , Humans , Necroptosis/immunology , Necrosis/immunology , Necrosis/metabolism , Neutrophil Activation , Neutrophils/immunology , Neutrophils/metabolism , Phagocytosis/immunology , Pyroptosis/immunology , Receptors, Death Domain/metabolism
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