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1.
Sci Adv ; 6(48)2020 11.
Article in English | MEDLINE | ID: covidwho-1388431

ABSTRACT

Acute respiratory distress syndrome is associated with a robust inflammatory response that damages the vascular endothelium, impairing gas exchange. While restoration of microcapillaries is critical to avoid mortality, therapeutic targeting of this process requires a greater understanding of endothelial repair mechanisms. Here, we demonstrate that lung endothelium possesses substantial regenerative capacity and lineage tracing reveals that native endothelium is the source of vascular repair after influenza injury. Ablation of chicken ovalbumin upstream promoter-transcription factor 2 (COUP-TF2) (Nr2f2), a transcription factor implicated in developmental angiogenesis, reduced endothelial proliferation, exacerbating viral lung injury in vivo. In vitro, COUP-TF2 regulates proliferation and migration through activation of cyclin D1 and neuropilin 1. Upon influenza injury, nuclear factor κB suppresses COUP-TF2, but surviving endothelial cells ultimately reestablish vascular homeostasis dependent on restoration of COUP-TF2. Therefore, stabilization of COUP-TF2 may represent a therapeutic strategy to enhance recovery from pathogens, including H1N1 influenza and SARS-CoV-2.


Subject(s)
COUP Transcription Factor II/metabolism , Endothelial Cells/metabolism , Endothelium, Vascular/metabolism , Influenza A Virus, H1N1 Subtype , Lung/cytology , Lung/physiology , Orthomyxoviridae Infections/metabolism , Regeneration/genetics , Animals , COUP Transcription Factor II/genetics , Cell Movement/genetics , Cell Proliferation/genetics , Disease Models, Animal , Female , Gene Knockout Techniques , HEK293 Cells , Humans , Male , Mice , Mice, Transgenic , Orthomyxoviridae Infections/virology , Transfection
2.
Clin Hemorheol Microcirc ; 78(2): 199-207, 2021.
Article in English | MEDLINE | ID: covidwho-1352794

ABSTRACT

INTRODUCTION: Coronavirus disease-19 (COVID-19) is a new type of epidemic pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The population is generally susceptible to COVID-19, which mainly causes lung injury. Some cases may develop severe acute respiratory distress syndrome (ARDS). Currently, ARDS treatment is mainly mechanical ventilation, but mechanical ventilation often causes ventilator-induced lung injury (VILI) accompanied by hypercapnia in 14% of patients. Extracorporeal carbon dioxide removal (ECCO2R) can remove carbon dioxide from the blood of patients with ARDS, correct the respiratory acidosis, reduce the tidal volume and airway pressure, and reduce the incidence of VILI. CASE REPORT: Two patients with critical COVID-19 combined with multiple organ failure undertook mechanical ventilation and suffered from hypercapnia. ECCO2R, combined with continuous renal replacement therapy (CRRT), was conducted concomitantly. In both cases (No. 1 and 2), the tidal volume and positive end-expiratory pressure (PEEP) were down-regulated before the treatment and at 1.5 hours, one day, three days, five days, eight days, and ten days after the treatment, together with a noticeable decrease in PCO2 and clear increase in PO2, while FiO2 decreased to approximately 40%. In case No 2, compared with the condition before treatment, the PCO2 decreased significantly with down-regulation in the tidal volume and PEEP and improvement in the pulmonary edema and ARDS after the treatment. CONCLUSION: ECCO2R combined with continuous blood purification therapy in patients with COVID-19 who are criti-cally ill and have ARDS and hypercapnia might gain both time and opportunity in the treatment, down-regulate the ventilator parameters, reduce the incidence of VILI and achieve favorable therapeutic outcomes.


Subject(s)
COVID-19/complications , Carbon Dioxide/isolation & purification , Extracorporeal Circulation/methods , Hemofiltration/methods , Hypercapnia/therapy , Respiratory Distress Syndrome/therapy , SARS-CoV-2/isolation & purification , Aged , COVID-19/transmission , COVID-19/virology , Humans , Hypercapnia/physiopathology , Hypercapnia/virology , Male , Positive-Pressure Respiration , Respiration, Artificial , Respiratory Distress Syndrome/physiopathology , Respiratory Distress Syndrome/virology
3.
Cell Rep Med ; 2(7): 100327, 2021 07 20.
Article in English | MEDLINE | ID: covidwho-1275765

ABSTRACT

Severe COVID-19 appears rare in children. This is unexpected, especially in young infants, who are vulnerable to severe disease caused by other respiratory viruses. We evaluate convalescent immune responses in 4 infants under 3 months old with confirmed COVID-19 who presented with mild febrile illness, alongside their parents, and adult controls recovered from confirmed COVID-19. Although not statistically significant, compared to seropositive adults, infants have high serum levels of IgG and IgA to SARS-CoV-2 spike protein, with a corresponding functional ability to block SARS-CoV-2 cellular entry. Infants also exhibit robust saliva anti-spike IgG and IgA responses. Spike-specific IFN-γ production by infant peripheral blood mononuclear cells appears restrained, but the frequency of spike-specific IFN-γ- and/or TNF-α-producing T cells is comparable between infants and adults. On principal-component analysis, infant immune responses appear distinct from their parents. Robust functional antibody responses alongside restrained IFN-γ production may help protect infants from severe COVID-19.


Subject(s)
Antibody Formation , COVID-19/immunology , Interferon-gamma/metabolism , Spike Glycoprotein, Coronavirus/immunology , Adult , Female , Humans , Immunoglobulin A , Immunoglobulin G , Infant , Infant, Newborn , Interferon-gamma/immunology , Leukocytes, Mononuclear/metabolism , Male , Young Adult
4.
J Infect Dis ; 223(9): 1503-1505, 2021 05 20.
Article in English | MEDLINE | ID: covidwho-1238202
5.
Int J Environ Res Public Health ; 18(9)2021 Apr 29.
Article in English | MEDLINE | ID: covidwho-1217076

ABSTRACT

BACKGROUND: This study was carried out to estimate the seroprevalence of SARS-CoV-2 antibodies in a Southern Italian population. METHODS: The study was performed among students and workers of the University of Campania "Luigi Vanvitelli" and the relative Teaching Hospital. Participants were invited to undergo a blood sampling, an interview or to complete a self-administered questionnaire. RESULTS: A total of 140 participants (5.8%) tested positive for SARS-CoV-2 antibodies. Positive SARS-CoV-2 test results increased significantly during the months of testing, and those who had had at least one symptom among fever, cough, dyspnea, loss of taste or smell and who had had contact with a family member/cohabitant with confirmed COVID-19 were more likely to test positive. Faculty members were less likely to have a positive test result compared to the healthcare workers (HCWs). Among HCWs, physicians showed the lowest rate of seroconversion (5.2%) compared to nurses (8.9%) and other categories (10%). Nurses and other HCWs compared to the physicians, those who had had at least one symptom among fever, cough, dyspnea, loss of taste or smell, and who had had contact with a family member/cohabitant with confirmed COVID-19 were more likely to test positive. CONCLUSIONS: The results have demonstrated that SARS-CoV-2 infection is rapidly spreading even in Southern Italy and confirm the substantial role of seroprevalence studies for the assessment of SARS-CoV-2 infection circulation and potential for further spreading.


Subject(s)
COVID-19 , SARS-CoV-2 , Adult , Health Personnel , Humans , Italy/epidemiology , Seroepidemiologic Studies
6.
Science ; 372(6543): 738-741, 2021 05 14.
Article in English | MEDLINE | ID: covidwho-1180894

ABSTRACT

Vaccination and infection promote the formation, tissue distribution, and clonal evolution of B cells, which encode humoral immune memory. We evaluated pediatric and adult blood and deceased adult organ donor tissues to determine convergent antigen-specific antibody genes of similar sequences shared between individuals. B cell memory varied for different pathogens. Polysaccharide antigen-specific clones were not exclusive to the spleen. Adults had higher clone frequencies and greater class switching in lymphoid tissues than blood, while pediatric blood had abundant class-switched convergent clones. Consistent with reported serology, prepandemic children had class-switched convergent clones to severe acute respiratory syndrome coronavirus 2 with weak cross-reactivity to other coronaviruses, while adult blood or tissues showed few such clones. These results highlight the prominence of early childhood B cell clonal expansions and cross-reactivity for future responses to novel pathogens.


Subject(s)
Antibodies, Viral/immunology , B-Lymphocytes/immunology , Coronavirus/immunology , Immunologic Memory , SARS-CoV-2/immunology , Adolescent , Adult , Aged , Aged, 80 and over , Aging , Child, Preschool , Cross Reactions , Ebolavirus/immunology , Female , Fetal Blood/immunology , Genes, Immunoglobulin , Humans , Immunoglobulin Class Switching , Immunoglobulin D/genetics , Immunoglobulin D/immunology , Immunoglobulin Heavy Chains/immunology , Immunoglobulin M/genetics , Immunoglobulin M/immunology , Infant , Lymph Nodes/immunology , Male , Middle Aged , Receptors, Antigen, B-Cell/immunology , Somatic Hypermutation, Immunoglobulin , Spleen/immunology , Young Adult
7.
J Transl Med ; 18(1): 422, 2020 11 10.
Article in English | MEDLINE | ID: covidwho-916977

ABSTRACT

BACKGROUND: In the present study the blood expression level of inflammatory response and autoimmunity associated long non-coding RNAs (lncRNAs) were compared in patients with different chronic respiratory diseases and investigated whether they could be used as biomarkers in these diseases. METHODS: In the discovery cohort, the gene expression level of 84 lncRNAs were measured in the blood of 24 adult patients including healthy controls and patients with asthma and COPD. In the replication cohort the expression of 6 selected lncRNAs were measured in 163 subjects including healthy controls and adults with allergic rhinitis, asthma, COPD and children with asthma. It was evaluated whether these lncRNAs can be used as diagnostic biomarkers for any studied disease. With systems biology analysis the biological functions of the selected lncRNAs were predicted. RESULTS: In the discovery cohort, the mean expression of 27 lncRNAs showed nominally significant differences in at least one comparison. OIP5-AS1, HNRNPU, RP11-325K4.3, JPX, RP11-282O18.3, MZF1-AS1 were selected for measurement in the replication cohort. Three lncRNAs (HNRNPU, RP11-325K4.3, JPX) expressed significantly higher in healthy children than in adult controls. All the mean expression level of the 6 lncRNAs differed significantly between adult allergic rhinitis patients and controls. RP11-325K4.3, HNRNPU and OIP5-AS1 expressed higher in allergic asthma than in non-allergic asthma. COPD and asthma differed in the expression of RP11-325K4.3 from each other. In examining of the lncRNAs as biomarkers the weighted accuracy (WA) values were especially high in the comparison of healthy controls and patients with allergic rhinitis. OIP5-AS1 and JPX achieved 0.98 and 0.9 WA values, respectively, and the combination of the selected lncRNAs also resulted in a high performance (WA = 0.98). Altogether, OIP5-AS1 had the highest discriminative power in case of three out of six comparisons. CONCLUSION: Differences were detected in the expression of circulating lncRNAs in chronic respiratory diseases. Some of these differences might be utilized as biomarkers and also suggest a possible role of these lncRNAs in the pathomechanism of these diseases. The lncRNAs and the associated pathways are potential therapeutic targets in these diseases, but naturally additional studies are needed for the confirmation of these results.


Subject(s)
Asthma/diagnosis , Pulmonary Disease, Chronic Obstructive/diagnosis , RNA, Long Noncoding , Rhinitis, Allergic/diagnosis , Adult , Biomarkers , Child , Humans , RNA, Long Noncoding/blood
8.
Transl Res ; 233: 104-116, 2021 07.
Article in English | MEDLINE | ID: covidwho-1051128

ABSTRACT

The p53/p21 pathway is activated in response to cell stress. However, its role in acute lung injury has not been elucidated. Acute lung injury is associated with disruption of the alveolo-capillary barrier leading to acute respiratory distress syndrome (ARDS). Mechanical ventilation may be necessary to support gas exchange in patients with ARDS, however, high positive airway pressures can cause regional overdistension of alveolar units and aggravate lung injury. Here, we report that acute lung injury and alveolar overstretching activate the p53/p21 pathway to maintain homeostasis and avoid massive cell apoptosis. A systematic pooling of transcriptomic data from animal models of lung injury demonstrates the enrichment of specific p53- and p21-dependent gene signatures and a validated senescence profile. In a clinically relevant, murine model of acid aspiration and mechanical ventilation, we observed changes in the nuclear envelope and the underlying chromatin, DNA damage and activation of the Tp53/p21 pathway. Absence of Cdkn1a decreased the senescent response, but worsened lung injury due to increased cell apoptosis. Conversely, treatment with lopinavir and/or ritonavir led to Cdkn1a overexpression and ameliorated cell apoptosis and lung injury. The activation of these mechanisms was associated with early markers of senescence, including expression of senescence-related genes and increases in senescence-associated heterochromatin foci in alveolar cells. Autopsy samples from lungs of patients with ARDS revealed increased senescence-associated heterochromatin foci. Collectively, these results suggest that acute lung injury activates p53/p21 as an antiapoptotic mechanism to ameliorate damage, but with the side effect of induction of senescence.


Subject(s)
Acute Lung Injury/metabolism , Cyclin-Dependent Kinase Inhibitor p21/metabolism , Acids/administration & dosage , Acids/toxicity , Acute Lung Injury/etiology , Acute Lung Injury/pathology , Animals , Apoptosis , Cellular Senescence , Cyclin-Dependent Kinase Inhibitor p21/deficiency , Cyclin-Dependent Kinase Inhibitor p21/genetics , DNA Damage , Disease Models, Animal , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Respiration, Artificial/adverse effects , Respiratory Distress Syndrome/etiology , Respiratory Distress Syndrome/metabolism , Respiratory Distress Syndrome/pathology , Signal Transduction , Stress, Mechanical , Tumor Suppressor Protein p53/deficiency , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism
9.
Transl Psychiatry ; 11(1): 179, 2021 03 19.
Article in English | MEDLINE | ID: covidwho-1142427

ABSTRACT

Microglia, the resident brain immune cells, play a critical role in normal brain development, and are impacted by the intrauterine environment, including maternal immune activation and inflammatory exposures. The COVID-19 pandemic presents a potential developmental immune challenge to the fetal brain, in the setting of maternal SARS-CoV-2 infection with its attendant potential for cytokine production and, in severe cases, cytokine storming. There is currently no biomarker or model for in utero microglial priming and function that might aid in identifying the neonates and children most vulnerable to neurodevelopmental morbidity, as microglia remain inaccessible in fetal life and after birth. This study aimed to generate patient-derived microglial-like cell models unique to each neonate from reprogrammed umbilical cord blood mononuclear cells, adapting and extending a novel methodology previously validated for adult peripheral blood mononuclear cells. We demonstrate that umbilical cord blood mononuclear cells can be used to create microglial-like cell models morphologically and functionally similar to microglia observed in vivo. We illustrate the application of this approach by generating microglia from cells exposed and unexposed to maternal SARS-CoV-2 infection. Our ability to create personalized neonatal models of fetal brain immune programming enables non-invasive insights into fetal brain development and potential childhood neurodevelopmental vulnerabilities for a range of maternal exposures, including COVID-19.


Subject(s)
Brain/growth & development , Brain/immunology , COVID-19/immunology , Cellular Reprogramming , Fetal Blood/immunology , Induced Pluripotent Stem Cells , Leukocytes, Mononuclear/immunology , Microglia/immunology , Pregnancy Complications, Infectious/immunology , Adult , Female , Humans , Infant, Newborn , Pregnancy
10.
Cell Biol Int ; 45(7): 1533-1545, 2021 Jul.
Article in English | MEDLINE | ID: covidwho-1141294

ABSTRACT

Polymorphonuclear neutrophilic granulocytes (PMNs) are the largest proportion of leukocytes in adult human blood that perform numerous functions, including phagocytosis, degranulation, generation of reactive oxygen species, and NETosis. Excessive neutrophil activity associates with hyperinflammation and tissue damage during pathologies such as inflammatory bowel disease, diabetes mellitus, tuberculosis, and coronavirus disease 2019. Nicotinic acetylcholine receptors (nAChRs) can modulate immune cells, including neutrophils, functions, therefore, nAChR ligands are considered as the potent agents for therapy of inflammation. Earlier it was shown, that about 30% of PMNs from the acute inflammatory site responded to nicotine by calcium spikes. In this study, we studied the generation of calcium spikes in murine granulocytes with different maturity level (evaluated by Gr-1 expression) isolated from bone marrow in response to ligands of nAChRs in control and under chronic nicotine consumption. It was found that nearly 20%-25% cells in the granulocyte population responded to nicotine or selective antagonists of different type of nAChRs (α-cobratoxin, GIC, and Vc1.1). We demonstrated that in the control group Ca2+ -mobilizing activity was regulated through α7 and α9α10 nAChRs in immature granulocytes (Gr-1int ), whereas in mature granulocytes (Gr-1hi ) it was regulated through α7, α3ß2, and α9-contained nAChRs. Sensitivity of PMNs to nicotine depended on their maturity level after chronic nicotine consumption. Gr-1int cells responded to nicotine through α7 and α9-contained nAChRs, while Gr-1hi did not respond to nicotine. Thus, calcium response to nAChR ligands in bone marrow PMNs depends on their maturity level.


Subject(s)
Antigens, Ly/metabolism , Bone Marrow Cells/drug effects , Calcium Signaling/drug effects , Calcium/metabolism , Cholinergic Agents/pharmacology , Granulocytes/drug effects , Receptors, Nicotinic/drug effects , Animals , Bone Marrow Cells/metabolism , Cells, Cultured , Granulocytes/metabolism , Ligands , Male , Mice, Inbred BALB C , Nicotine/pharmacology , Nicotinic Agonists/pharmacology , Nicotinic Antagonists/pharmacology , Receptors, Nicotinic/metabolism
11.
Arkh Patol ; 83(1): 35-43, 2021.
Article in Russian | MEDLINE | ID: covidwho-1055339

ABSTRACT

Autopsy material and medical history were studied and analyzed in a 20-year-old male patient who had died from COVID-19 infection with the development of acute SARS-CoV-2-associated hemorrhagic necrotizing encephalopathy in adults with obvious endothelial dysfunction confirmed by virological examination of the autopsy material. In this case, the brain structures displayed the main found histopathologic signs: widespread vasculitis (endotheliitis) with varying degrees of segmental and total endothelial destruction; thrombosis mainly of the vessels of the microcirculatory bed; parenchymal hemorrhagic necrosis and inflammation (encephalitis); severe necrobiotic damage to neurons. Cerebrovascular immune damages and hypercoagulable states, which were observed in some acute viral neuroinfections, are the basis for the neurological complications of COVID-19. In this case of bicausal diagnosis (the presence of a comorbidity), the primary disease contributed to the acute progression of the background disease (secondary infiltrative tuberculosis with the development of specific pleuritis and pneumothorax with the addition of acute bilateral focal confluent bronchopneumonia with a history of undifferentiated immunodeficiency syndrome. Emphasis is laid on the possibility and importance of involving the brain structures in the process in COVID-19 for the timely diagnosis of emerging neurological disorders. A brief literature review is given.


Subject(s)
Brain Diseases , COVID-19 , Nervous System Diseases , Adult , Humans , Male , Microcirculation , SARS-CoV-2 , Young Adult
12.
Front Pharmacol ; 11: 615398, 2020.
Article in English | MEDLINE | ID: covidwho-1000126

ABSTRACT

Many drugs have been approved for clinical trials for the treatment of COVID-19 disease, focusing on either antiviral or anti-inflammatory approaches. Combining antiviral and anti-inflammatory drugs or therapies together may be more effective. Human alpha-1 antitrypsin (A1AT) is a blood circulating glycoprotein that is best known as a protease inhibitor. It has been used to treat emphysema patients with A1AT deficiency for decades. We and others have demonstrated its role in reducing acute lung injury by inhibiting inflammation, cell death, coagulation, and neutrophil elastase activation. Recently, A1AT has been found to inhibit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection by inhibiting transmembrane serine protease 2 (TMPRSS2), a protease involved in the entry of SARS-CoV-2 into host cells. This dual role of both antiviral infection and anti-inflammation makes A1AT a unique and excellent candidate for COVID-19 treatment. Three clinical trials of A1AT for COVID-19 treatment have recently been approved in several countries. It is important to determine whether A1AT can prevent the progress from moderate to severe lung injury and eventually to be used to treat COVID-19 patients with acute respiratory distress syndrome.

13.
Biomed Res Int ; 2020: 2909673, 2020.
Article in English | MEDLINE | ID: covidwho-999319

ABSTRACT

Difficulties have risen while managing Acute Respiratory Distress Syndrome (ARDS) caused by COVID-19, although it meets the Berlin definition. Severe hypoxemia with near-normal compliance was noted along with coagulopathy. Understanding the precise pathophysiology of this atypical ARDS will assist researchers and physicians in improving their therapeutic approach. Previous work is limited to postmortem studies, while our report addresses patients under protective lung mechanical ventilation. An open-lung minithoracotomy was performed in 3 patients who developed ARDS related to COVID-19 and were admitted to the intensive care unit to carry out a pathological and microbiological analysis on lung tissue biopsy. Diffused alveolar damage with hyaline membranes was found, as well as plurifocal fibrin microthrombi and vascular congestion in all patients' specimens. Microbiological cultures were negative, whereas qualitative Reversed Transcriptase Polymerase Chain Reaction (RT-PCR) detected SARS-CoV-2 in the pulmonary parenchyma and pleural fluid in two patients. COVID-19 causes progressive ARDS with onset of severe hypoxemia, underlying a dual mechanism: shunt effect through diffused alveolar damage and dead space effect through thrombotic injuries in microvascular beds. It seems reasonable to manage this ventilation-perfusion ratio mismatch using a high dose of anticoagulant combined with glucocorticoids.


Subject(s)
COVID-19/drug therapy , COVID-19/pathology , Lung/drug effects , Lung/pathology , Respiratory Distress Syndrome/drug therapy , Aged , Anticoagulants/therapeutic use , Biopsy/methods , COVID-19/virology , Glucocorticoids/therapeutic use , Humans , Lung/virology , Male , Respiration, Artificial , Respiratory Distress Syndrome/virology , SARS-CoV-2/drug effects
14.
mBio ; 11(6)2020 12 11.
Article in English | MEDLINE | ID: covidwho-975645

ABSTRACT

SARS-CoV-2 causes COVID-19, an acute respiratory distress syndrome (ARDS) characterized by pulmonary edema, viral pneumonia, multiorgan dysfunction, coagulopathy, and inflammation. SARS-CoV-2 uses angiotensin-converting enzyme 2 (ACE2) receptors to infect and damage ciliated epithelial cells in the upper respiratory tract. In alveoli, gas exchange occurs across an epithelial-endothelial barrier that ties respiration to endothelial cell (EC) regulation of edema, coagulation, and inflammation. How SARS-CoV-2 dysregulates vascular functions to cause ARDS in COVID-19 patients remains an enigma focused on dysregulated EC responses. Whether SARS-CoV-2 directly or indirectly affects functions of the endothelium remains to be resolved and is critical to understanding SARS-CoV-2 pathogenesis and therapeutic targets. We demonstrate that primary human ECs lack ACE2 receptors at protein and RNA levels and that SARS-CoV-2 is incapable of directly infecting ECs derived from pulmonary, cardiac, brain, umbilical vein, or kidney tissues. In contrast, pulmonary ECs transduced with recombinant ACE2 receptors are infected by SARS-CoV-2 and result in high viral titers (∼1 × 107/ml), multinucleate syncytia, and EC lysis. SARS-CoV-2 infection of ACE2-expressing ECs elicits procoagulative and inflammatory responses observed in COVID-19 patients. The inability of SARS-CoV-2 to directly infect and lyse ECs without ACE2 expression explains the lack of vascular hemorrhage in COVID-19 patients and indicates that the endothelium is not a primary target of SARS-CoV-2 infection. These findings are consistent with SARS-CoV-2 indirectly activating EC programs that regulate thrombosis and endotheliitis in COVID-19 patients and focus strategies on therapeutically targeting epithelial and inflammatory responses that activate the endothelium or initiate limited ACE2-independent EC infection.IMPORTANCE SARS-CoV-2 infects pulmonary epithelial cells through ACE2 receptors and causes ARDS. COVID-19 causes progressive respiratory failure resulting from diffuse alveolar damage and systemic coagulopathy, thrombosis, and capillary inflammation that tie alveolar responses to EC dysfunction. This has prompted theories that SARS-CoV-2 directly infects ECs through ACE2 receptors, yet SARS-CoV-2 antigen has not been colocalized with ECs and prior studies indicate that ACE2 colocalizes with alveolar epithelial cells and vascular smooth muscle cells, not ECs. Here, we demonstrate that primary human ECs derived from lung, kidney, heart, brain, and umbilical veins require expression of recombinant ACE2 receptors in order to be infected by SARS-CoV-2. However, SARS-CoV-2 lytically infects ACE2-ECs and elicits procoagulative and inflammatory responses observed in COVID-19 patients. These findings suggest a novel mechanism of COVID-19 pathogenesis resulting from indirect EC activation, or infection of a small subset of ECs by an ACE2-independent mechanism, that transforms rationales and targets for therapeutic intervention.


Subject(s)
Blood Coagulation Factors , Endothelial Cells/virology , Inflammation , Peptidyl-Dipeptidase A/genetics , SARS-CoV-2/pathogenicity , Animals , Cells, Cultured , Chlorocebus aethiops , Endothelial Cells/immunology , Endothelial Cells/pathology , Humans , Recombinant Proteins , Vero Cells
15.
Mol Ther ; 28(12): 2691-2702, 2020 12 02.
Article in English | MEDLINE | ID: covidwho-927132

ABSTRACT

Preventing the progression to acute respiratory distress syndrome (ARDS) in COVID-19 is an unsolved challenge. The involvement of T cell immunity in this exacerbation remains unclear. To identify predictive markers of COVID-19 progress and outcome, we analyzed peripheral blood of 10 COVID-19-associated ARDS patients and 35 mild/moderate COVID-19 patients, not requiring intensive care. Using multi-parametric flow cytometry, we compared quantitative, phenotypic, and functional characteristics of circulating bulk immune cells, as well as SARS-CoV-2 S-protein-reactive T cells between the two groups. ARDS patients demonstrated significantly higher S-protein-reactive CD4+ and CD8+ T cells compared to non-ARDS patients. Of interest, comparison of circulating bulk T cells in ARDS patients to non-ARDS patients demonstrated decreased frequencies of CD4+ and CD8+ T cell subsets, with activated memory/effector T cells expressing tissue migration molecule CD11a++. Importantly, survival from ARDS (4/10) was accompanied by a recovery of the CD11a++ T cell subsets in peripheral blood. Conclusively, data on S-protein-reactive polyfunctional T cells indicate the ability of ARDS patients to generate antiviral protection. Furthermore, decreased frequencies of activated memory/effector T cells expressing tissue migratory molecule CD11a++ observed in circulation of ARDS patients might suggest their involvement in ARDS development and propose the CD11a-based immune signature as a possible prognostic marker.


Subject(s)
COVID-19/immunology , Immunologic Memory/immunology , Pandemics , Respiratory Distress Syndrome/immunology , Adult , Aged , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , COVID-19/virology , Female , Humans , Male , Membrane Glycoproteins/immunology , Middle Aged , Respiratory Distress Syndrome/pathology , Respiratory Distress Syndrome/virology , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , T-Lymphocyte Subsets/immunology
16.
Front Cardiovasc Med ; 7: 153, 2020.
Article in English | MEDLINE | ID: covidwho-838591

ABSTRACT

The emergence of the COVID-19 virus and the subsequent pandemic have driven a great deal of research activity. The effects of COVID-19 are caused by the severe respiratory syndrome coronavirus 2 (SARS-CoV-2) and it is the underlying actions of SARs-CoV-2 virions on the endothelial glycocalyx that we consider here. One of the key factors in COVID-19 infection is its almost unique age-related profile, with a doubling in mortality every 10 years after the age of 50. The endothelial glycocalyx layer is essential in maintaining normal fluid homeostasis, but is fragile and prone to pathophysiological damage. It is physiologically significant in capillary microcirculation and in fluid distribution to the tissues. Human serum albumin (HSA), the most abundant protein in plasma, is created in the liver which also maintains its concentration, but this reduces by 10-15% after 50 years of age. HSA transports hormones, free fatty acids and maintains oncotic pressure, but SARS-CoV-2 virions bind competitively to HSA diminishing its normal transport function. Furthermore, hypoalbuminemia is frequently observed in patients with such conditions as diabetes, hypertension, and chronic heart failure, i.e., those most vulnerable to SARS-CoV-2 infection. Hypoalbuminemia, coagulopathy, and vascular disease have been linked in COVID-19 and have been shown to predict outcome independent of age and morbidity. Hypoalbuminemia is also known factor in sepsis and Acute respiratory distress syndrome (ARDS) occurs when fluids build-up in the alveoli and it is associated with sepsis, whose mechanism is systemic, being associated with the fluid and logistic mechanisms of the circulation. Glycocalyx damage is associated with changes plasma protein concentration, particularly HSA and blockage of albumin transport can produce the systemic symptoms seen in SARS-CoV-2 infection and sepsis. We therefore conclude that albumin binding to SARS-CoV-2 virions may inhibit the formation of the endothelial glycocalyx by inhibition of albumin transport binding sites. We postulate that albumin therapy to replace bound albumin might alleviate some of the symptoms leading to sepsis and that clinical trials to test this postulation should be initiated as a matter of urgency.

17.
J Allergy Clin Immunol ; 147(1): 81-91, 2021 01.
Article in English | MEDLINE | ID: covidwho-802735

ABSTRACT

BACKGROUND: Severe immunopathology may drive the deleterious manifestations that are observed in the advanced stages of coronavirus disease 2019 (COVID-19) but are poorly understood. OBJECTIVE: Our aim was to phenotype leukocyte subpopulations and the cytokine milieu in the lungs and blood of critically ill patients with COVID-19 acute respiratory distress syndrome (ARDS). METHODS: We consecutively included patients less than 72 hours after intubation following informed consent from their next of kin. Bronchoalveolar lavage fluid was evaluated by microscopy; bronchoalveolar lavage fluid and blood were assessed by 10-color flow cytometry and a multiplex cytokine panel. RESULTS: Four mechanically ventilated patients (aged 40-75 years) with moderate-to-severe COVID-19 ARDS were included. Immature neutrophils dominated in both blood and lungs, whereas CD4 and CD8 T-cell lymphopenia was observed in the 2 compartments. However, regulatory T cells and TH17 cells were found in higher fractions in the lung. Lung CD4 and CD8 T cells and macrophages expressed an even higher upregulation of activation markers than in blood. A wide range of cytokines were expressed at high levels both in the blood and in the lungs, most notably, IL-1RA, IL-6, IL-8, IP-10, and monocyte chemoattactant protein-1, consistent with hyperinflammation. CONCLUSION: COVID-19 ARDS exhibits a distinct immunologic profile in the lungs, with a depleted and exhausted CD4 and CD8 T-cell population that resides within a heavily hyperinflammatory milieu.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , COVID-19/immunology , Lung/immunology , Lymphopenia/immunology , Respiratory Distress Syndrome/immunology , SARS-CoV-2/immunology , Th17 Cells/immunology , Adult , Aged , CD8-Positive T-Lymphocytes/pathology , COVID-19/pathology , Cross-Sectional Studies , Cytokines/immunology , Female , Humans , Immunophenotyping , Lung/pathology , Lymphopenia/pathology , Male , Middle Aged , Respiratory Distress Syndrome/pathology , Th17 Cells/pathology
18.
J Clin Med ; 9(9)2020 Sep 05.
Article in English | MEDLINE | ID: covidwho-750661

ABSTRACT

BACKGROUND: Blood coagulation disorders commonly occur with severe coronavirus disease 2019 (COVID-19). However, there is only limited evidence on differentiating the pattern of the hemostatic parameters from those of typical sepsis-induced coagulopathy (SIC). METHODS: To elucidate the specific pattern of coagulopathy induced by COVID-19 pneumonia, this retrospective, observational study targeted consecutive adult patients with COVID-19-induced acute respiratory distress syndrome (ARDS) and compared hemostatic biomarkers with non-COVID-19-induced septic ARDS. Multilevel mixed-effects regression analysis was performed and Kaplan-Meier failure curves were constructed. RESULTS: We enrolled 24 patients with COVID-19-induced ARDS and 200 patients with non-COVID-19-induced ARDS. Platelet count, antithrombin activity, and prothrombin time in the COVID-19 group were almost within normal range and time series alterations of these markers were significantly milder than the non-COVID-19 group (p = 0.052, 0.037, and 0.005, respectively). However, fibrin/fibrinogen degradation product and D-dimer were significantly higher in the COVID-19 group (p = 0.001, 0.002, respectively). COVID-19 patients had moderately high levels of thrombin-antithrombin complex and plasmin-alpha2-plasmin inhibitor complex but normal plasminogen activator inhibitor-1 level. CONCLUSIONS: The hematological phenotype of COVID-19-induced coagulopathy is quite different from that in typical SIC characterized by systemic hypercoagulation and suppressed fibrinolysis. Instead, local thrombus formation might be promoted in severe COVID-19.

19.
J Clin Pharm Ther ; 45(6): 1515-1519, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-733228

ABSTRACT

WHAT IS KNOWN AND OBJECTIVE: This article summarizes the effects of sivelestat on acute lung injury/acute respiratory distress syndrome (ALI/ARDS) or ARDS with coagulopathy, both of which are frequently seen in patients with COVID-19. COMMENT: COVID-19 patients are more susceptible to thromboembolic events, including disseminated intravascular coagulation (DIC). Various studies have emphasized the role of neutrophil elastase (NE) in the development of DIC in patients with ARDS and sepsis. It has been shown that NE inhibition by sivelestat mitigates ALI through amelioration of injuries in alveolar epithelium and vascular endothelium, as well as reversing the neutrophil-mediated increased vascular permeability. WHAT IS NEW AND CONCLUSIONS: Sivelestat, a selective NE inhibitor, has not been evaluated for its possible therapeutic effects against SARS-CoV-2 infection. Based on its promising beneficial effects in underlying complications of COVID-19, sivelestat could be considered as a promising modality for better management of COVID-19-induced ALI/ARDS or coagulopathy.


Subject(s)
Acute Lung Injury/drug therapy , COVID-19/drug therapy , Disseminated Intravascular Coagulation/drug therapy , Glycine/analogs & derivatives , Proteinase Inhibitory Proteins, Secretory/therapeutic use , Respiratory Distress Syndrome/drug therapy , Sulfonamides/therapeutic use , Acute Lung Injury/etiology , COVID-19/complications , Disseminated Intravascular Coagulation/etiology , Glycine/therapeutic use , Humans , Respiratory Distress Syndrome/etiology , Treatment Outcome
20.
Circulation ; 142(12): 1176-1189, 2020 09 22.
Article in English | MEDLINE | ID: covidwho-696368

ABSTRACT

BACKGROUND: Severe acute respiratory syndrome corona virus 2 infection causes severe pneumonia (coronavirus disease 2019 [COVID-19]), but the mechanisms of subsequent respiratory failure and complicating renal and myocardial involvement are poorly understood. In addition, a systemic prothrombotic phenotype has been reported in patients with COVID-19. METHODS: A total of 62 subjects were included in our study (n=38 patients with reverse transcriptase polymerase chain reaction-confirmed COVID-19 and n=24 non-COVID-19 controls). We performed histopathologic assessment of autopsy cases, surface marker-based phenotyping of neutrophils and platelets, and functional assays for platelet, neutrophil functions, and coagulation tests, as well. RESULTS: We provide evidence that organ involvement and prothrombotic features in COVID-19 are linked by immunothrombosis. We show that, in COVID-19, inflammatory microvascular thrombi are present in the lung, kidney, and heart, containing neutrophil extracellular traps associated with platelets and fibrin. Patients with COVID-19 also present with neutrophil-platelet aggregates and a distinct neutrophil and platelet activation pattern in blood, which changes with disease severity. Whereas cases of intermediate severity show an exhausted platelet and hyporeactive neutrophil phenotype, patients severely affected with COVID-19 are characterized by excessive platelet and neutrophil activation in comparison with healthy controls and non-COVID-19 pneumonia. Dysregulated immunothrombosis in severe acute respiratory syndrome corona virus 2 pneumonia is linked to both acute respiratory distress syndrome and systemic hypercoagulability. CONCLUSIONS: Taken together, our data point to immunothrombotic dysregulation as a key marker of disease severity in COVID-19. Further work is necessary to determine the role of immunothrombosis in COVID-19.


Subject(s)
Coronavirus Infections/diagnosis , Pneumonia, Viral/diagnosis , Respiratory Insufficiency/etiology , Betacoronavirus/genetics , Betacoronavirus/isolation & purification , Blood Coagulation Disorders/diagnosis , Blood Coagulation Disorders/etiology , Blood Platelets/cytology , Blood Platelets/metabolism , Blood Platelets/pathology , COVID-19 , Case-Control Studies , Coronavirus Infections/complications , Coronavirus Infections/pathology , Coronavirus Infections/virology , Extracellular Traps/metabolism , Humans , Kidney/pathology , Lung/pathology , Neutrophils/cytology , Neutrophils/metabolism , Neutrophils/pathology , Pandemics , Phenotype , Platelet Activation , Pneumonia, Viral/complications , Pneumonia, Viral/pathology , Pneumonia, Viral/virology , Respiratory Insufficiency/diagnosis , SARS-CoV-2 , Severity of Illness Index , Thrombosis/complications , Thrombosis/diagnosis
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