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1.
Sci Rep ; 11(1): 21725, 2021 11 05.
Article in English | MEDLINE | ID: covidwho-1504567

ABSTRACT

SARS-CoV-2 enters the intestine by the spike protein binding to angiotensin-converting enzyme 2 (ACE2) receptors in enterocyte apical membranes, leading to diarrhea in some patients. Early treatment of COVID-19-associated diarrhea could relieve symptoms and limit viral spread within the gastrointestinal (GI) tract. Diosmectite, an aluminomagnesium silicate adsorbent clay with antidiarrheal effects, is recommended in some COVID-19 management protocols. In rotavirus models, diosmectite prevents pathogenic effects by binding the virus and its enterotoxin. We tested the trapping and anti-inflammatory properties of diosmectite in a SARS-CoV-2 model. Trapping effects were tested in Caco-2 cells using spike protein receptor-binding domain (RBD) and heat-inactivated SARS-CoV-2 preparations. Trapping was assessed by immunofluorescence, alone or in the presence of cells. The effect of diosmectite on nuclear factor kappa B (NF-kappaB) activation and CXCL10 secretion induced by the spike protein RBD and heat-inactivated SARS-CoV-2 were analyzed by Western blot and ELISA, respectively. Diosmectite bound the spike protein RBD and SARS-CoV-2 preparation, and inhibited interaction of the spike protein RBD with ACE2 receptors on the Caco-2 cell surface. Diosmectite exposure also inhibited NF-kappaB activation and CXCL10 secretion. These data provide direct evidence that diosmectite can bind SARS-CoV-2 components and inhibit downstream inflammation, supporting a mechanistic rationale for consideration of diosmectite as a management option for COVID-19-associated diarrhea.


Subject(s)
COVID-19/drug therapy , Chemokine CXCL10/metabolism , NF-kappa B p50 Subunit/metabolism , SARS-CoV-2 , Silicates/chemistry , Adsorption , Aluminum Compounds/chemistry , Angiotensin-Converting Enzyme 2/metabolism , Anti-Inflammatory Agents , Binding Sites , Caco-2 Cells , Chromatography, Liquid , Clay , Diarrhea/etiology , Diarrhea/therapy , Enterocytes/metabolism , Gastroenterology , Humans , Magnesium Compounds/chemistry , Mass Spectrometry , Molecular Docking Simulation , Molecular Dynamics Simulation , Protein Binding/drug effects , Protein Domains , Rotavirus , Silicates/metabolism
2.
Cell Rep ; 37(1): 109773, 2021 10 05.
Article in English | MEDLINE | ID: covidwho-1442298

ABSTRACT

SARS-CoV-2 infection in children is less severe than it is in adults. We perform a longitudinal analysis of the early innate responses in children and adults with mild infection within household clusters. Children display fewer symptoms than adults do, despite similar initial viral load, and mount a robust anti-viral immune signature typical of the SARS-CoV-2 infection and characterized by early interferon gene responses; increases in cytokines, such as CXCL10 and GM-CSF; and changes in blood cell numbers. When compared with adults, the antiviral response resolves faster (within a week of symptoms), monocytes and dendritic cells are more transiently activated, and genes associated with B cell activation appear earlier in children. Nonetheless, these differences do not have major effects on the quality of SARS-CoV-2-specific antibody responses. Our findings reveal that better early control of inflammation as observed in children may be key for rapidly controlling infection and limiting the disease course.


Subject(s)
Antibodies, Viral/immunology , COVID-19/genetics , COVID-19/immunology , Cytokines/metabolism , Immunity, Innate , SARS-CoV-2/immunology , Transcriptome , Adaptive Immunity , Adolescent , Adult , B-Lymphocytes/metabolism , COVID-19/virology , Chemokine CXCL10/metabolism , Child , Child, Preschool , Granulocyte-Macrophage Colony-Stimulating Factor/metabolism , Humans , Infant , Inflammation/virology , Interferons/metabolism , Longitudinal Studies , Middle Aged , Monocytes/metabolism , Sequence Analysis, RNA , Viral Load , Young Adult
3.
J Exp Med ; 218(8)2021 08 02.
Article in English | MEDLINE | ID: covidwho-1387679

ABSTRACT

Initial replication of SARS-CoV-2 in the upper respiratory tract is required to establish infection, and the replication level correlates with the likelihood of viral transmission. Here, we examined the role of host innate immune defenses in restricting early SARS-CoV-2 infection using transcriptomics and biomarker-based tracking in serial patient nasopharyngeal samples and experiments with airway epithelial organoids. SARS-CoV-2 initially replicated exponentially, with a doubling time of ∼6 h, and induced interferon-stimulated genes (ISGs) in the upper respiratory tract, which rose with viral replication and peaked just as viral load began to decline. Rhinovirus infection before SARS-CoV-2 exposure accelerated ISG responses and prevented SARS-CoV-2 replication. Conversely, blocking ISG induction during SARS-CoV-2 infection enhanced viral replication from a low infectious dose. These results show that the activity of ISG-mediated defenses at the time of SARS-CoV-2 exposure impacts infection progression and that the heterologous antiviral response induced by a different virus can protect against SARS-CoV-2.


Subject(s)
COVID-19/immunology , COVID-19/virology , Immunity, Innate/physiology , Nasopharynx/virology , Adult , Aged , Aged, 80 and over , Angiotensin-Converting Enzyme 2/genetics , Case-Control Studies , Chemokine CXCL10/metabolism , Disease Susceptibility/immunology , Female , Gene Expression Profiling , Host-Pathogen Interactions/physiology , Humans , Interferons/genetics , Interferons/immunology , Interferons/metabolism , Male , Middle Aged , Picornaviridae Infections/immunology , Picornaviridae Infections/virology , SARS-CoV-2/genetics , SARS-CoV-2/physiology , Viral Load , Virus Replication
4.
J Immunol ; 207(5): 1229-1238, 2021 09 01.
Article in English | MEDLINE | ID: covidwho-1344412

ABSTRACT

Infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) or seasonal influenza may lead to respiratory failure requiring intubation and mechanical ventilation. The pathophysiology of this respiratory failure is attributed to local immune dysregulation, but how the immune response to viral infection in the lower airways of the human lung differs between individuals with respiratory failure and those without is not well understood. We used quantitative multiparameter flow cytometry and multiplex cytokine assays to evaluate matched blood and bronchoalveolar lavage (BAL) samples from control human subjects, subjects with symptomatic seasonal influenza who did not have respiratory failure, and subjects with severe seasonal influenza or SARS-CoV-2 infection with respiratory failure. We find that severe cases are associated with an influx of nonclassical monocytes, activated T cells, and plasmablast B cells into the lower airways. Cytokine concentrations were not elevated in the lower airways of moderate influenza patients compared with controls; however, 28 of 35 measured cytokines were significantly elevated in severe influenza, severe SARS-CoV-2 infection, or both. We noted the largest elevations in IL-6, IP-10, MCP-1, and IL-8. IL-1 family cytokines and RANTES were higher in severe influenza infection than severe SARS-CoV-2 infection. Interestingly, only the concentration of IP-10-correlated between blood and BAL during severe infection. Our results demonstrate inflammatory immune dysregulation in the lower airways during severe viral pneumonia that is distinct from lower airway responses seen in human patients with symptomatic, but not severe, illness and suggest that measurement of blood IP-10 concentration may predict this unique dysregulation.


Subject(s)
COVID-19/immunology , Influenza A virus/physiology , Pneumonia, Viral/immunology , Respiratory System/immunology , SARS-CoV-2/physiology , Adult , Aged , Blood Proteins/metabolism , Bronchoalveolar Lavage Fluid/immunology , COVID-19/diagnosis , Chemokine CXCL10/metabolism , Cohort Studies , Female , Humans , Inflammation Mediators/metabolism , Influenza, Human/immunology , Male , Middle Aged , Prospective Studies , Respiratory Insufficiency , Severity of Illness Index
5.
Science ; 371(6536): 1374-1378, 2021 03 26.
Article in English | MEDLINE | ID: covidwho-1255508

ABSTRACT

The COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continually poses serious threats to global public health. The main protease (Mpro) of SARS-CoV-2 plays a central role in viral replication. We designed and synthesized 32 new bicycloproline-containing Mpro inhibitors derived from either boceprevir or telaprevir, both of which are approved antivirals. All compounds inhibited SARS-CoV-2 Mpro activity in vitro, with 50% inhibitory concentration values ranging from 7.6 to 748.5 nM. The cocrystal structure of Mpro in complex with MI-23, one of the most potent compounds, revealed its interaction mode. Two compounds (MI-09 and MI-30) showed excellent antiviral activity in cell-based assays. In a transgenic mouse model of SARS-CoV-2 infection, oral or intraperitoneal treatment with MI-09 or MI-30 significantly reduced lung viral loads and lung lesions. Both also displayed good pharmacokinetic properties and safety in rats.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , Coronavirus 3C Proteases/antagonists & inhibitors , Protease Inhibitors/pharmacology , Animals , Antiviral Agents/chemistry , Antiviral Agents/therapeutic use , COVID-19/pathology , COVID-19/virology , Cell Line , Cell Survival/drug effects , Chemokine CXCL10/metabolism , Disease Models, Animal , Drug Design , Humans , Interferon-beta/metabolism , Lung/immunology , Lung/pathology , Lung/virology , Mice , Mice, Transgenic , Oligopeptides , Proline/analogs & derivatives , Protease Inhibitors/chemistry , Protease Inhibitors/therapeutic use , Protease Inhibitors/toxicity , Rats , Rats, Sprague-Dawley , Viral Load/drug effects , Virus Replication
6.
Crit Care ; 24(1): 632, 2020 11 02.
Article in English | MEDLINE | ID: covidwho-901906

ABSTRACT

BACKGROUND: COVID-19-related ARDS has unique features when compared with ARDS from other origins, suggesting a distinctive inflammatory pathogenesis. Data regarding the host response within the lung are sparse. The objective is to compare alveolar and systemic inflammation response patterns, mitochondrial alarmin release, and outcomes according to ARDS etiology (i.e., COVID-19 vs. non-COVID-19). METHODS: Bronchoalveolar lavage fluid and plasma were obtained from 7 control, 7 non-COVID-19 ARDS, and 14 COVID-19 ARDS patients. Clinical data, plasma, and epithelial lining fluid (ELF) concentrations of 45 inflammatory mediators and cell-free mitochondrial DNA were measured and compared. RESULTS: COVID-19 ARDS patients required mechanical ventilation (MV) for significantly longer, even after adjustment for potential confounders. There was a trend toward higher concentrations of plasma CCL5, CXCL2, CXCL10, CD40 ligand, IL-10, and GM-CSF, and ELF concentrations of CXCL1, CXCL10, granzyme B, TRAIL, and EGF in the COVID-19 ARDS group compared with the non-COVID-19 ARDS group. Plasma and ELF CXCL10 concentrations were independently associated with the number of ventilator-free days, without correlation between ELF CXCL-10 and viral load. Mitochondrial DNA plasma and ELF concentrations were elevated in all ARDS patients, with no differences between the two groups. ELF concentrations of mitochondrial DNA were correlated with alveolar cell counts, as well as IL-8 and IL-1ß concentrations. CONCLUSION: CXCL10 could be one key mediator involved in the dysregulated immune response. It should be evaluated as a candidate biomarker that may predict the duration of MV in COVID-19 ARDS patients. Targeting the CXCL10-CXCR3 axis could also be considered as a new therapeutic approach. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03955887.


Subject(s)
Chemokine CXCL10/metabolism , Coronavirus Infections/complications , Pneumonia, Viral/complications , Respiration, Artificial/statistics & numerical data , Respiratory Distress Syndrome/etiology , Respiratory Distress Syndrome/therapy , Adult , Aged , COVID-19 , Case-Control Studies , Female , Humans , Male , Middle Aged , Pandemics , Prospective Studies , Time Factors
7.
Int J Mol Sci ; 21(9)2020 Apr 30.
Article in English | MEDLINE | ID: covidwho-143805

ABSTRACT

Severe acute respiratory syndrome-associated coronavirus (SARS-CoV) initiates the cytokine/chemokine storm-mediated lung injury. The SARS-CoV unique domain (SUD) with three macrodomains (N, M, and C), showing the G-quadruplex binding activity, was examined the possible role in SARS pathogenesis in this study. The chemokine profile analysis indicated that SARS-CoV SUD significantly up-regulated the expression of CXCL10, CCL5 and interleukin (IL)-1ß in human lung epithelial cells and in the lung tissues of the mice intratracheally instilled with the recombinant plasmids. Among the SUD subdomains, SUD-MC substantially activated AP-1-mediated CXCL10 expression in vitro. In the wild type mice, SARS-CoV SUD-MC triggered the pulmonary infiltration of macrophages and monocytes, inducing CXCL10-mediated inflammatory responses and severe diffuse alveolar damage symptoms. Moreover, SUD-MC actuated NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome-dependent pulmonary inflammation, as confirmed by the NLRP3 inflammasome inhibitor and the NLRP3-/- mouse model. This study demonstrated that SARS-CoV SUD modulated NLRP3 inflammasome-dependent CXCL10-mediated pulmonary inflammation, providing the potential therapeutic targets for developing the antiviral agents.


Subject(s)
Chemokine CXCL10/metabolism , Inflammasomes/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , SARS Virus/metabolism , Viral Proteins/metabolism , Animals , Bronchoalveolar Lavage Fluid/chemistry , Bronchoalveolar Lavage Fluid/immunology , Cell Line , Chemokine CXCL10/genetics , Disease Models, Animal , Humans , Lung/metabolism , Lung/pathology , Mice , Mice, Inbred C57BL , Mice, Knockout , Monocytes/immunology , Monocytes/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/deficiency , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , Pneumonia/pathology , Pneumonia/virology , Promoter Regions, Genetic , SARS Virus/isolation & purification , Severe Acute Respiratory Syndrome/pathology , Severe Acute Respiratory Syndrome/virology , Up-Regulation , Viral Proteins/chemistry , Viral Proteins/genetics
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