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2.
PLoS One ; 16(11): e0259165, 2021.
Article in English | MEDLINE | ID: covidwho-1581791

ABSTRACT

The rapid, sensitive and specific detection of SARS-CoV-2 is critical in responding to the current COVID-19 outbreak. In this proof-of-concept study, we explored the potential of targeted mass spectrometry (MS) based proteomics for the detection of SARS-CoV-2 proteins in both research samples and clinical specimens. First, we assessed the limit of detection for several SARS-CoV-2 proteins by parallel reaction monitoring (PRM) MS in infected Vero E6 cells. For tryptic peptides of Nucleocapsid protein, the limit of detection was estimated to be in the mid-attomole range (9E-13 g). Next, this PRM methodology was applied to the detection of viral proteins in various COVID-19 patient clinical specimens, such as sputum and nasopharyngeal swabs. SARS-CoV-2 proteins were detected in these samples with high sensitivity in all specimens with PCR Ct values <24 and in several samples with higher CT values. A clear relationship was observed between summed MS peak intensities for SARS-CoV-2 proteins and Ct values reflecting the abundance of viral RNA. Taken together, these results suggest that targeted MS based proteomics may have the potential to be used as an additional tool in COVID-19 diagnostics.


Subject(s)
COVID-19/diagnosis , Proteomics , SARS-CoV-2/isolation & purification , Viral Proteins/isolation & purification , Animals , COVID-19/pathology , COVID-19/virology , Chlorocebus aethiops , Humans , Mass Spectrometry , Nucleocapsid/genetics , Nucleocapsid/isolation & purification , Phosphoproteins/genetics , Phosphoproteins/isolation & purification , Proteome/genetics , SARS-CoV-2/genetics , SARS-CoV-2/pathogenicity , Sputum/virology , Vero Cells , Viral Proteins/genetics
3.
J Clin Immunol ; 2021 Nov 12.
Article in English | MEDLINE | ID: covidwho-1509277

ABSTRACT

PURPOSE: To study the effect of interferon-α2 auto-antibodies (IFN-α2 Abs) on clinical and virological outcomes in critically ill COVID-19 patients and the risk of IFN-α2 Abs transfer during convalescent plasma treatment. METHODS: Sera from healthy controls, cases of COVID-19, and other respiratory illness were tested for IFN-α2 Abs by ELISA and a pseudo virus-based neutralization assay. The effects of disease severity, sex, and age on the risk of having neutralizing IFN-α2 Abs were determined. Longitudinal analyses were performed to determine association between IFN-α2 Abs and survival and viral load and whether serum IFN-α2 Abs appeared after convalescent plasma transfusion. RESULTS: IFN-α2 neutralizing sera were found only in COVID-19 patients, with proportions increasing with disease severity and age. In the acute stage of COVID-19, all sera from patients with ELISA-detected IFN-α2 Abs (13/164, 7.9%) neutralized levels of IFN-α2 exceeding physiological concentrations found in human plasma and this was associated with delayed viral clearance. Convalescent plasma donors that were anti-IFN-α2 ELISA positive (3/118, 2.5%) did not neutralize the same levels of IFN-α2. Neutralizing serum IFN-α2 Abs were associated with delayed viral clearance from the respiratory tract. CONCLUSIONS: IFN-α2 Abs were detected by ELISA and neutralization assay in COVID-19 patients, but not in ICU patients with other respiratory illnesses. The presence of neutralizing IFN-α2 Abs in critically ill COVID-19 is associated with delayed viral clearance. IFN-α2 Abs in COVID-19 convalescent plasma donors were not neutralizing in the conditions tested.

4.
Journal of Clinical Investigation ; 131(21):1-13, 2021.
Article in English | ProQuest Central | ID: covidwho-1503264

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of coronavirus disease 2019 (COVID-19). Little is known about the interplay between preexisting immunity to endemic seasonal coronaviruses and the development of a SARS-CoV-2-specific IgG response. We investigated the kinetics, breadth, magnitude, and level of cross-reactivity of IgG antibodies against SARS-CoV-2 and heterologous seasonal and epidemic coronaviruses at the clonal level in patients with mild or severe COVID-19 as well as in disease control patients. We assessed antibody reactivity to nucleocapsid and spike antigens and correlated this IgG response to SARS-CoV-2 neutralization. Patients with COVID-19 mounted a mostly type-specific SARS-CoV-2 response. Additionally, IgG clones directed against a seasonal coronavirus were boosted in patients with severe COVID-19. These boosted clones showed limited cross-reactivity and did not neutralize SARS-CoV-2. These findings indicate a boost of poorly protective CoV-specific antibodies in patients with COVID-19 that correlated with disease severity, revealing "original antigenic sin."

5.
Science ; 371(6536): 1379-1382, 2021 03 26.
Article in English | MEDLINE | ID: covidwho-1476374

ABSTRACT

Containment of the COVID-19 pandemic requires reducing viral transmission. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is initiated by membrane fusion between the viral and host cell membranes, which is mediated by the viral spike protein. We have designed lipopeptide fusion inhibitors that block this critical first step of infection and, on the basis of in vitro efficacy and in vivo biodistribution, selected a dimeric form for evaluation in an animal model. Daily intranasal administration to ferrets completely prevented SARS-CoV-2 direct-contact transmission during 24-hour cohousing with infected animals, under stringent conditions that resulted in infection of 100% of untreated animals. These lipopeptides are highly stable and thus may readily translate into safe and effective intranasal prophylaxis to reduce transmission of SARS-CoV-2.


Subject(s)
COVID-19/transmission , Lipopeptides/administration & dosage , Membrane Fusion/drug effects , SARS-CoV-2/drug effects , Viral Fusion Protein Inhibitors/administration & dosage , Virus Internalization/drug effects , Administration, Intranasal , Animals , COVID-19/prevention & control , COVID-19/virology , Chlorocebus aethiops , Disease Models, Animal , Drug Design , Ferrets , Lipopeptides/chemistry , Lipopeptides/pharmacokinetics , Lipopeptides/pharmacology , Mice , Pre-Exposure Prophylaxis , SARS-CoV-2/isolation & purification , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/metabolism , Tissue Distribution , Vero Cells , Viral Fusion Protein Inhibitors/chemistry , Viral Fusion Protein Inhibitors/pharmacokinetics , Viral Fusion Protein Inhibitors/pharmacology
6.
Nat Commun ; 12(1): 5498, 2021 09 17.
Article in English | MEDLINE | ID: covidwho-1428814

ABSTRACT

Rapid identification of host genes essential for virus replication may expedite the generation of therapeutic interventions. Genetic screens are often performed in transformed cell lines that poorly represent viral target cells in vivo, leading to discoveries that may not be translated to the clinic. Intestinal organoids are increasingly used to model human disease and are amenable to genetic engineering. To discern which host factors are reliable anti-coronavirus therapeutic targets, we generate mutant clonal IOs for 19 host genes previously implicated in coronavirus biology. We verify ACE2 and DPP4 as entry receptors for SARS-CoV/SARS-CoV-2 and MERS-CoV respectively. SARS-CoV-2 replication in IOs does not require the endosomal Cathepsin B/L proteases, but specifically depends on the cell surface protease TMPRSS2. Other TMPRSS family members were not essential. The newly emerging coronavirus variant B.1.1.7, as well as SARS-CoV and MERS-CoV similarly depended on TMPRSS2. These findings underscore the relevance of non-transformed human models for coronavirus research, identify TMPRSS2 as an attractive pan-coronavirus therapeutic target, and demonstrate that an organoid knockout biobank is a valuable tool to investigate the biology of current and future emerging coronaviruses.


Subject(s)
Angiotensin-Converting Enzyme 2/genetics , Biological Specimen Banks , CRISPR-Cas Systems , Coronavirus , Dipeptidyl Peptidase 4/genetics , Organoids/metabolism , Serine Endopeptidases/genetics , COVID-19 , Cell Line , Humans , Middle East Respiratory Syndrome Coronavirus , SARS-CoV-2 , Transcriptome , Virus Replication
7.
J Clin Invest ; 131(21)2021 11 01.
Article in English | MEDLINE | ID: covidwho-1403157

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of coronavirus disease 2019 (COVID-19). Little is known about the interplay between preexisting immunity to endemic seasonal coronaviruses and the development of a SARS-CoV-2-specific IgG response. We investigated the kinetics, breadth, magnitude, and level of cross-reactivity of IgG antibodies against SARS-CoV-2 and heterologous seasonal and epidemic coronaviruses at the clonal level in patients with mild or severe COVID-19 as well as in disease control patients. We assessed antibody reactivity to nucleocapsid and spike antigens and correlated this IgG response to SARS-CoV-2 neutralization. Patients with COVID-19 mounted a mostly type-specific SARS-CoV-2 response. Additionally, IgG clones directed against a seasonal coronavirus were boosted in patients with severe COVID-19. These boosted clones showed limited cross-reactivity and did not neutralize SARS-CoV-2. These findings indicate a boost of poorly protective CoV-specific antibodies in patients with COVID-19 that correlated with disease severity, revealing "original antigenic sin."


Subject(s)
B-Lymphocytes/immunology , B-Lymphocytes/virology , COVID-19/immunology , COVID-19/virology , Coronavirus/immunology , SARS-CoV-2/immunology , Adult , Aged , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Antibody Specificity , Case-Control Studies , Coronavirus Infections/immunology , Coronavirus Infections/virology , Coronavirus Nucleocapsid Proteins/immunology , Cross Reactions , Female , Host Microbial Interactions/immunology , Humans , Immunoglobulin G/blood , Longitudinal Studies , Male , Middle Aged , Pandemics , Phosphoproteins/immunology , Seasons , Severity of Illness Index , Spike Glycoprotein, Coronavirus/immunology
8.
Elife ; 102021 04 09.
Article in English | MEDLINE | ID: covidwho-1389777

ABSTRACT

Virus propagation methods generally use transformed cell lines to grow viruses from clinical specimens, which may force viruses to rapidly adapt to cell culture conditions, a process facilitated by high viral mutation rates. Upon propagation in VeroE6 cells, SARS-CoV-2 may mutate or delete the multibasic cleavage site (MBCS) in the spike protein. Previously, we showed that the MBCS facilitates serine protease-mediated entry into human airway cells (Mykytyn et al., 2021). Here, we report that propagating SARS-CoV-2 on the human airway cell line Calu-3 - that expresses serine proteases - prevents cell culture adaptations in the MBCS and directly adjacent to the MBCS (S686G). Similar results were obtained using a human airway organoid-based culture system for SARS-CoV-2 propagation. Thus, in-depth knowledge on the biology of a virus can be used to establish methods to prevent cell culture adaptation.


Subject(s)
Epithelial Cells , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/genetics , Virus Cultivation/methods , Virus Internalization , Animals , Cell Line , Chlorocebus aethiops , Epithelial Cells/cytology , Epithelial Cells/metabolism , Epithelial Cells/virology , Humans , Proteolysis , Respiratory System/cytology , Respiratory System/virology , Serine Proteases/metabolism
9.
Nat Commun ; 11(1): 2511, 2020 05 14.
Article in English | MEDLINE | ID: covidwho-1387317

ABSTRACT

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

10.
Viruses ; 13(8)2021 08 23.
Article in English | MEDLINE | ID: covidwho-1367929

ABSTRACT

The post-acute phase of SARS-CoV-2 infection was investigated in rhesus (Macaca mulatta) and cynomolgus macaques (Macaca fascicularis). During the acute phase of infection, SARS-CoV-2 was shed via the nose and throat, and viral RNA was occasionally detected in feces. This phase coincided with a transient change in systemic immune activation. Even after the alleged resolution of the infection, computed tomography (CT) and positron emission tomography (PET)-CT revealed pulmonary lesions and activated tracheobronchial lymph nodes in all animals. Post-mortem histological examination of the lung tissue revealed mostly marginal or resolving minimal lesions that were indicative of SARS-CoV-2 infection. Evidence for SARS-CoV-2-induced histopathology was also found in extrapulmonary tissue samples, such as conjunctiva, cervical, and mesenteric lymph nodes. However, 5-6 weeks after SARS-CoV-2 exposure, upon necropsy, viral RNA was still detectable in a wide range of tissue samples in 50% of the macaques and included amongst others the heart, the respiratory tract and surrounding lymph nodes, salivary gland, and conjunctiva. Subgenomic messenger RNA was detected in the lungs and tracheobronchial lymph nodes, indicative of ongoing virus replication during the post-acute phase. These results could be relevant for understanding the long-term consequences of COVID-19 in humans.


Subject(s)
COVID-19/pathology , COVID-19/virology , Lung/pathology , SARS-CoV-2/physiology , Animals , Antibodies, Viral/blood , COVID-19/immunology , Cytokines/blood , Disease Models, Animal , Humans , Lung/virology , Lymph Nodes/pathology , Lymph Nodes/physiopathology , Macaca fascicularis , Macaca mulatta , RNA, Messenger/analysis , RNA, Viral/analysis , Respiratory System/pathology , Respiratory System/virology , SARS-CoV-2/immunology , Virus Replication
11.
One Health ; 13: 100313, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1364384

ABSTRACT

Assays to measure SARS-CoV-2-specific neutralizing antibodies are important to monitor seroprevalence, to study asymptomatic infections and to reveal (intermediate) hosts. A recently developed assay, the surrogate virus-neutralization test (sVNT) is a quick and commercially available alternative to the "gold standard" virus neutralization assay using authentic virus, and does not require processing at BSL-3 level. The assay relies on the inhibition of binding of the receptor binding domain (RBD) on the spike (S) protein to human angiotensin-converting enzyme 2 (hACE2) by antibodies present in sera. As the sVNT does not require species- or isotype-specific conjugates, it can be similarly used for antibody detection in human and animal sera. In this study, we used 298 sera from PCR-confirmed COVID-19 patients and 151 sera from patients confirmed with other coronavirus or other (respiratory) infections, to evaluate the performance of the sVNT. To analyze the use of the assay in a One Health setting, we studied the presence of RBD-binding antibodies in 154 sera from nine animal species (cynomolgus and rhesus macaques, ferrets, rabbits, hamsters, cats, cattle, mink and dromedary camels). The sVNT showed a moderate to high sensitivity and a high specificity using sera from confirmed COVID-19 patients (91.3% and 100%, respectively) and animal sera (93.9% and 100%), however it lacked sensitivity to detect low titers. Significant correlations were found between the sVNT outcomes and PRNT50 and the Wantai total Ig and IgM ELISAs. While species-specific validation will be essential, our results show that the sVNT holds promise in detecting RBD-binding antibodies in multiple species.

12.
Dis Model Mech ; 14(6)2021 06 01.
Article in English | MEDLINE | ID: covidwho-1295507

ABSTRACT

The COVID-19 pandemic has emphasised the need to develop effective treatments to combat emerging viruses. Model systems that poorly represent a virus' cellular environment, however, may impede research and waste resources. Collaborations between cell biologists and virologists have led to the rapid development of representative organoid model systems to study severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We believe that lung organoids, in particular, have advanced our understanding of SARS-CoV-2 pathogenesis, and have laid a foundation to study future pandemic viruses and develop effective treatments.


Subject(s)
COVID-19/virology , Lung/virology , Models, Biological , Organoids/virology , SARS-CoV-2 , Animals , COVID-19/epidemiology , Humans , Pandemics , Pulmonary Alveoli/virology , Research Design/trends , SARS-CoV-2/pathogenicity
13.
Proc Natl Acad Sci U S A ; 118(28)2021 07 13.
Article in English | MEDLINE | ID: covidwho-1284760

ABSTRACT

Severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2) has emerged as the infectious agent causing the pandemic coronavirus disease 2019 (COVID-19) with dramatic consequences for global human health and economics. Previously, we reached clinical evaluation with our vector vaccine based on modified vaccinia virus Ankara (MVA) against the Middle East respiratory syndrome coronavirus (MERS-CoV), which causes an infection in humans similar to SARS and COVID-19. Here, we describe the construction and preclinical characterization of a recombinant MVA expressing full-length SARS-CoV-2 spike (S) protein (MVA-SARS-2-S). Genetic stability and growth characteristics of MVA-SARS-2-S, plus its robust expression of S protein as antigen, make it a suitable candidate vaccine for industrial-scale production. Vaccinated mice produced S-specific CD8+ T cells and serum antibodies binding to S protein that neutralized SARS-CoV-2. Prime-boost vaccination with MVA-SARS-2-S protected mice sensitized with a human ACE2-expressing adenovirus from SARS-CoV-2 infection. MVA-SARS-2-S is currently being investigated in a phase I clinical trial as aspirant for developing a safe and efficacious vaccine against COVID-19.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19 Vaccines/immunology , COVID-19/prevention & control , Spike Glycoprotein, Coronavirus/immunology , Animals , COVID-19 Vaccines/standards , Dose-Response Relationship, Immunologic , Humans , Mice , Mice, Inbred BALB C , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/genetics , T-Lymphocytes , Vaccination , Vaccinia virus
14.
Curr Opin Virol ; 50: 8-16, 2021 10.
Article in English | MEDLINE | ID: covidwho-1284020

ABSTRACT

SARS-CoV-2 emerged in China as a zoonotic virus in December 2019. The virus proved to be human-to-human transmissible and its global spread resulted in the ongoing COVID-19 pandemic, associated with high morbidity and mortality. Vaccines were developed at an unprecedented speed and proved to be efficacious in preventing disease, but it remains to be determined if vaccines are able to interrupt transmission. Moreover, virus variants of concern continue to emerge that appear more transmissible and/or less sensitive to virus-specific immune responses. Here, we briefly review the role of animal models in assessing prophylactic and therapeutic options to interrupt SARS-CoV-2 transmission.


Subject(s)
COVID-19/transmission , Disease Models, Animal , SARS-CoV-2 , Animals , COVID-19/prevention & control , Cricetinae , Humans
15.
J Infect Dis ; 223(12): 2020-2028, 2021 06 15.
Article in English | MEDLINE | ID: covidwho-1246725

ABSTRACT

Effective clinical intervention strategies for coronavirus disease 2019 (COVID-19) are urgently needed. Although several clinical trials have evaluated use of convalescent plasma containing virus-neutralizing antibodies, levels of neutralizing antibodies are usually not assessed and the effectiveness has not been proven. We show that hamsters treated prophylactically with a 1:2560 titer of human convalescent plasma or a 1:5260 titer of monoclonal antibody were protected against weight loss, had a significant reduction of virus replication in the lungs, and showed reduced pneumonia. Interestingly, this protective effect was lost with a titer of 1:320 of convalescent plasma. These data highlight the importance of screening plasma donors for high levels of neutralizing antibodies. Our data show that prophylactic administration of high levels of neutralizing antibody, either monoclonal or from convalescent plasma, prevent severe SARS-CoV-2 pneumonia in a hamster model, and could be used as an alternative or complementary to other antiviral treatments for COVID-19.


Subject(s)
Antibodies, Monoclonal/therapeutic use , Antibodies, Neutralizing/therapeutic use , COVID-19/therapy , Lung/pathology , SARS-CoV-2/immunology , Virus Replication/drug effects , Animals , Antibodies, Monoclonal/administration & dosage , Antibodies, Neutralizing/administration & dosage , COVID-19/immunology , Cricetinae , Disease Models, Animal , Humans , Immunization, Passive , Lung/drug effects , Virus Shedding/drug effects , Weight Loss/drug effects
16.
Nat Commun ; 12(1): 3189, 2021 05 27.
Article in English | MEDLINE | ID: covidwho-1246368

ABSTRACT

In a randomized clinical trial of 86 hospitalized COVID-19 patients comparing standard care to treatment with 300mL convalescent plasma containing high titers of neutralizing SARS-CoV-2 antibodies, no overall clinical benefit was observed. Using a comprehensive translational approach, we unravel the virological and immunological responses following treatment to disentangle which COVID-19 patients may benefit and should be the focus of future studies. Convalescent plasma is safe, does not improve survival, has no effect on the disease course, nor does plasma enhance viral clearance in the respiratory tract, influence SARS-CoV-2 antibody development or serum proinflammatory cytokines levels. Here, we show that the vast majority of patients already had potent neutralizing SARS-CoV-2 antibodies at hospital admission and with comparable titers to carefully selected plasma donors. This resulted in the decision to terminate the trial prematurely. Treatment with convalescent plasma should be studied early in the disease course or at least preceding autologous humoral response development.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/immunology , COVID-19/therapy , Cytokines/blood , SARS-CoV-2/immunology , Aged , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Blood Donors , COVID-19/blood , COVID-19/virology , Disease Progression , Female , Hospitalization , Humans , Immunization, Passive , Immunoglobulin G/blood , Kaplan-Meier Estimate , Male , Middle Aged , Spike Glycoprotein, Coronavirus/immunology , Treatment Outcome
17.
Sci Immunol ; 6(59)2021 05 25.
Article in English | MEDLINE | ID: covidwho-1243688

ABSTRACT

The emergence of SARS-CoV-2 variants harboring mutations in the spike (S) protein has raised concern about potential immune escape. Here, we studied humoral and cellular immune responses to wild type SARS-CoV-2 and the B.1.1.7 and B.1.351 variants of concern in a cohort of 121 BNT162b2 mRNA-vaccinated health care workers (HCW). Twenty-three HCW recovered from mild COVID-19 disease and exhibited a recall response with high levels of SARS-CoV-2-specific functional antibodies and virus-specific T cells after a single vaccination. Specific immune responses were also detected in seronegative HCW after one vaccination, but a second dose was required to reach high levels of functional antibodies and cellular immune responses in all individuals. Vaccination-induced antibodies cross-neutralized the variants B.1.1.7 and B.1.351, but the neutralizing capacity and Fc-mediated functionality against B.1.351 was consistently 2- to 4-fold lower than to the homologous virus. In addition, peripheral blood mononuclear cells were stimulated with peptide pools spanning the mutated S regions of B.1.1.7 and B.1.351 to detect cross-reactivity of SARS-CoV-2-specific T cells with variants. Importantly, we observed no differences in CD4+ T-cell activation in response to variant antigens, indicating that the B.1.1.7 and B.1.351 S proteins do not escape T-cell-mediated immunity elicited by the wild type S protein. In conclusion, this study shows that some variants can partially escape humoral immunity induced by SARS-CoV-2 infection or BNT162b2 vaccination, but S-specific CD4+ T-cell activation is not affected by the mutations in the B.1.1.7 and B.1.351 variants.


Subject(s)
Antibodies, Viral/immunology , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , COVID-19/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , COVID-19 Vaccines/immunology , Cell Line , Cross Reactions/immunology , Humans , Immunologic Memory/immunology , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Vaccination
18.
J Infect Dis ; 223(9): 1512-1521, 2021 05 20.
Article in English | MEDLINE | ID: covidwho-1238201

ABSTRACT

Lower respiratory tract (LRT) disease induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can deteriorate to acute respiratory distress syndrome (ARDS). Because the release of neutrophil extracellular traps (NETs) is implicated in ARDS pathogenesis, we investigated the presence of NETs and correlates of pathogenesis in blood and LRT samples of critically ill patients with COVID-19. Plasma NET levels peaked early after intensive care unit admission and were correlated with the SARS-CoV-2 RNA load in sputum and levels of neutrophil-recruiting chemokines and inflammatory markers in plasma samples. The baseline plasma NET quantity was correlated with disease severity but was not associated with soluble markers of thrombosis or with development of thrombosis. High NET levels were present in LRT samples and persisted during the course of COVID-19, consistent with the detection of NETs in bronchi and alveolar spaces in lung tissue from deceased patient with COVID-19. Thus, NETs are produced and retained in the LRT of critically ill patients with COVID-19 and could contribute to SARS-CoV-2-induced ARDS disease.


Subject(s)
Bronchoalveolar Lavage Fluid/virology , COVID-19/complications , COVID-19/pathology , Extracellular Traps/virology , Respiratory Distress Syndrome/etiology , Respiratory Distress Syndrome/pathology , SARS-CoV-2 , Adult , Aged , Biomarkers , Chemokines/blood , Cohort Studies , Computed Tomography Angiography , Critical Illness , Enzyme-Linked Immunosorbent Assay , Female , Humans , Immunohistochemistry , Male , Middle Aged , Netherlands/epidemiology , Prospective Studies , Severity of Illness Index , Thrombosis/virology , Viral Load
19.
Eur J Immunol ; 51(7): 1774-1784, 2021 07.
Article in English | MEDLINE | ID: covidwho-1151899

ABSTRACT

Optimal vaccines are needed for sustained suppression of SARS-CoV-2 and other novel coronaviruses. Here, we developed a recombinant type 5 adenovirus vector encoding the gene for the SARS-CoV-2 S1 subunit antigen (Ad5.SARS-CoV-2-S1) for COVID-19 immunization and evaluated its immunogenicity in mice. A single immunization with Ad5.SARS-CoV-2-S1 via S.C. injection or I.N delivery induced robust antibody and cellular immune responses. Vaccination elicited significant S1-specific IgG, IgG1, and IgG2a endpoint titers as early as 2 weeks, and the induced antibodies were long lasting. I.N. and S.C. administration of Ad5.SARS-CoV-2-S1 produced S1-specific GC B cells in cervical and axillary LNs, respectively. Moreover, I.N. and S.C. immunization evoked significantly greater antigen-specific T-cell responses compared to unimmunized control groups with indications that S.C. injection was more effective than I.N. delivery in eliciting cellular immune responses. Mice vaccinated by either route demonstrated significantly increased virus-specific neutralization antibodies on weeks 8 and 12 compared to control groups, as well as BM antibody forming cells (AFC), indicative of long-term immunity. Thus, this Ad5-vectored SARS-CoV-2 vaccine candidate showed promising immunogenicity following delivery to mice by S.C. and I.N. routes of administration, supporting the further development of Ad-based vaccines against COVID-19 and other infectious diseases for sustainable global immunization programs.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19/immunology , COVID-19/prevention & control , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Adenoviridae/genetics , Adenoviridae/immunology , Animals , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , B-Lymphocytes/immunology , Immunity, Cellular/immunology , Immunity, Humoral/immunology , Immunoglobulin G/immunology , Mice , Mice, Inbred BALB C , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , T-Lymphocytes/immunology , Vaccination
20.
Nat Commun ; 12(1): 1715, 2021 03 17.
Article in English | MEDLINE | ID: covidwho-1139739

ABSTRACT

The coronavirus spike glycoprotein, located on the virion surface, is the key mediator of cell entry and the focus for development of protective antibodies and vaccines. Structural studies show exposed sites on the spike trimer that might be targeted by antibodies with cross-species specificity. Here we isolated two human monoclonal antibodies from immunized humanized mice that display a remarkable cross-reactivity against distinct spike proteins of betacoronaviruses including SARS-CoV, SARS-CoV-2, MERS-CoV and the endemic human coronavirus HCoV-OC43. Both cross-reactive antibodies target the stem helix in the spike S2 fusion subunit which, in the prefusion conformation of trimeric spike, forms a surface exposed membrane-proximal helical bundle. Both antibodies block MERS-CoV infection in cells and provide protection to mice from lethal MERS-CoV challenge in prophylactic and/or therapeutic models. Our work highlights an immunogenic and vulnerable site on the betacoronavirus spike protein enabling elicitation of antibodies with unusual binding breadth.


Subject(s)
Antibodies, Monoclonal, Humanized/immunology , Betacoronavirus/immunology , Epitopes/immunology , Spike Glycoprotein, Coronavirus/immunology , Animals , Antibodies, Monoclonal, Humanized/therapeutic use , Antibodies, Neutralizing/immunology , Antibodies, Neutralizing/therapeutic use , Antibodies, Viral/immunology , Betacoronavirus/classification , Camelus , Coronavirus Infections/drug therapy , Coronavirus Infections/virology , Cross Reactions , Epitopes/chemistry , Epitopes/genetics , Humans , Mice , Protein Conformation , Protein Subunits , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics
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