Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 20
Filter
1.
Eur J Immunol ; 52(4): 646-655, 2022 04.
Article in English | MEDLINE | ID: covidwho-1661608

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), an infectious disease characterized by strong induction of inflammatory cytokines, progressive lung inflammation, and potentially multiorgan dysfunction. It remains unclear how SARS-CoV-2 infection leads to immune activation. The Spike (S) protein of SARS-CoV-2 has been suggested to trigger TLR4 and thereby activate immunity. Here, we have investigated the role of TLR4 in SARS-CoV-2 infection and immunity. Neither exposure of isolated S protein, SARS-CoV-2 pseudovirus nor primary SARS-CoV-2 isolate induced TLR4 activation in a TLR4-expressing cell line. Human monocyte-derived DCs express TLR4 but not angiotensin converting enzyme 2 (ACE2), and DCs were not infected by SARS-CoV-2. Notably, neither S protein nor SARS-CoV-2 induced DC maturation or cytokines, indicating that both S protein and SARS-CoV-2 virus particles do not trigger extracellular TLRs including TLR4. Ectopic expression of ACE2 in DCs led to efficient infection by SARS-CoV-2 and, strikingly, efficient type I IFN and cytokine responses. These data strongly suggest that not extracellular TLRs but intracellular viral sensors are key players in sensing SARS-CoV-2. These data imply that SARS-CoV-2 escapes direct sensing by TLRs, which might underlie the lack of efficient immunity to SARS-CoV-2 early during infection.


Subject(s)
COVID-19 , Dendritic Cells , Spike Glycoprotein, Coronavirus , Toll-Like Receptor 4 , COVID-19/immunology , Cell Line , Dendritic Cells/immunology , Humans , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/immunology , Toll-Like Receptor 4/immunology
2.
Diagn Microbiol Infect Dis ; 102(4): 115650, 2022 Apr.
Article in English | MEDLINE | ID: covidwho-1648986

ABSTRACT

Massive vaccination programs are being carried out to limit the SARS-CoV-2 pandemic that started in December 2019. Serological tests are of major importance as an indicator of circulation of the virus and to assess how vaccine-induced immunity progresses. An Enzyme-Linked Immunosorbent Assay (ELISA) and a Lateral Flow Assay (LFA) have been developed based on the SARS-CoV-2 recombinant Receptor Binding Domain (RBD) and the combination of Spike and Nucleoprotein, respectively. The validation with 1272 serum samples by comparison with INgezim COVID 19 DR showed good diagnostic performance (sensitivity: 93.2%-97.2%; specificity: 98.3%-99.3%) for detection of previous contact with SARS-CoV-2. Moreover, according to our results, these assays can help in the serosurveillance during and after vaccination, by detecting the humoral immune response as soon as 15 days postvaccination and identifying low-respondents. Hence, these tests could play a key role in the progression to a COVID-19 free world, helping to adjust future vaccination protocols.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Viral , COVID-19/diagnosis , COVID-19/prevention & control , Humans , Sensitivity and Specificity , Spike Glycoprotein, Coronavirus , Vaccination
3.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-294493

ABSTRACT

Delineating the origins and properties of antibodies elicited by SARS-CoV-2 infection and vaccination is critical for understanding their benefits and potential shortcomings. Therefore, we investigated the SARS-CoV-2 spike (S)-reactive B cell repertoire in unexposed individuals by flow cytometry and single-cell sequencing. We found that ~82% of SARS-CoV-2 S-reactive B cells show a naive phenotype, which represents an unusually high fraction of total human naive B cells (~0.1%). Approximately 10% of these naive S-reactive B cells shared an IGHV1-69/IGKV3-11 B cell receptor pairing, an enrichment of 18-fold compared to the complete naive repertoire. A proportion of memory B cells, comprising switched (~0.05%) and unswitched B cells (~0.04%), was also reactive with S and some of these cells were reactive with ADAMTS13, which is associated with thrombotic thrombocytopenia. Following SARS-CoV-2 infection, we report an average 37-fold enrichment of IGHV1-69/IGKV3-11 B cell receptor pairing in the S-reactive memory B cells compared to the unselected memory repertoire. This class of B cells targets a previously undefined non-neutralizing epitope on the S2 subunit that becomes exposed on S proteins used in approved vaccines when they transition away from the native pre-fusion state because of instability. These findings can help guide the improvement of SARS-CoV-2 vaccines.

4.
NPJ Vaccines ; 6(1): 146, 2021 Dec 03.
Article in English | MEDLINE | ID: covidwho-1550286

ABSTRACT

The emergence of SARS-CoV-2 variants that are more resistant to antibody-mediated neutralization pose a new hurdle in combating the COVID-19 pandemic. Although vaccines based on the original Wuhan sequence have been shown to be effective at preventing COVID-19, their efficacy is likely to be decreased against more neutralization-resistant variants-of-concern (VOC), in particular, the Beta variant originating in South Africa. We assessed, in mice, rabbits, and non-human primates, whether a third vaccination with experimental Wuhan-based Spike vaccines could alleviate this problem. Our data show that a third immunization improves neutralizing antibody titers against the variants-of-concern, Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), and Delta (B.1.617.2). After three vaccinations, the level of neutralization against Beta was similar to the level of neutralization against the original strain after two vaccinations, suggesting that simply providing a third immunization could nullify the reduced activity of current vaccines against VOC.

5.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-293588

ABSTRACT

Delineating the origins and properties of antibodies elicited by SARS-CoV-2 infection and vaccination is critical for understanding their benefits and potential shortcomings. Therefore, we investigated the SARS-CoV-2 spike (S)-reactive B cell repertoire in unexposed individuals by flow cytometry and single-cell sequencing. We found that ~82% of SARS-CoV-2 S-reactive B cells show a naive phenotype, which represents an unusually high fraction of total human naive B cells (~0.1%). Approximately 10% of these naive S-reactive B cells shared an IGHV1-69/IGKV3-11 B cell receptor pairing, an enrichment of 18-fold compared to the complete naive repertoire. A proportion of memory B cells, comprising switched (~0.05%) and unswitched B cells (~0.04%), was also reactive with S and some of these cells were reactive with ADAMTS13, which is associated with thrombotic thrombocytopenia. Following SARS-CoV-2 infection, we report an average 37-fold enrichment of IGHV1-69/IGKV3-11 B cell receptor pairing in the S-reactive memory B cells compared to the unselected memory repertoire. This class of B cells targets a previously undefined non-neutralizing epitope on the S2 subunit that becomes exposed on S proteins used in approved vaccines when they transition away from the native pre-fusion state because of instability. These findings can help guide the improvement of SARS-CoV-2 vaccines.

6.
[Unspecified Source]; 2020.
Preprint in English | [Unspecified Source] | ID: ppcovidwho-292779

ABSTRACT

Most antibodies isolated from COVID-19 patients are specific to SARS-CoV-2. COVA1-16 is a relatively rare antibody that also cross-neutralizes SARS-CoV. Here we determined a crystal structure of COVA1-16 Fab with the SARS-CoV-2 RBD, and a negative-stain EM reconstruction with the spike glycoprotein trimer, to elucidate the structural basis of its cross-reactivity. COVA1-16 binds a highly conserved epitope on the SARS-CoV-2 RBD, mainly through a long CDR H3, and competes with ACE2 binding due to steric hindrance rather than epitope overlap. COVA1-16 binds to a flexible up conformation of the RBD on the spike and relies on antibody avidity for neutralization. These findings, along with structural and functional rationale for the epitope conservation, provide a blueprint for development of more universal SARS-like coronavirus vaccines and therapies.

7.
ACS Cent Sci ; 7(11): 1863-1873, 2021 Nov 24.
Article in English | MEDLINE | ID: covidwho-1526050

ABSTRACT

Determining how antibodies interact with the spike (S) protein of the SARS-CoV-2 virus is critical for combating COVID-19. Structural studies typically employ simplified, truncated constructs that may not fully recapitulate the behavior of the original complexes. Here, we combine two single particle mass analysis techniques (mass photometry and charge-detection mass spectrometry) to enable the measurement of full IgG binding to the trimeric SARS-CoV-2 S ectodomain. Our experiments reveal that antibodies targeting the S-trimer typically prefer stoichiometries lower than the symmetry-predicted 3:1 binding. We determine that this behavior arises from the interplay of steric clashes and avidity effects that are not reflected in common antibody constructs (i.e., Fabs). Surprisingly, these substoichiometric complexes are fully effective at blocking ACE2 binding despite containing free receptor binding sites. Our results highlight the importance of studying antibody/antigen interactions using complete, multimeric constructs and showcase the utility of single particle mass analyses in unraveling these complex interactions.

8.
Nat Commun ; 12(1): 6097, 2021 10 20.
Article in English | MEDLINE | ID: covidwho-1475295

ABSTRACT

Effective treatments against Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) are urgently needed. Monoclonal antibodies have shown promising results in patients. Here, we evaluate the in vivo prophylactic and therapeutic effect of COVA1-18, a neutralizing antibody highly potent against the B.1.1.7 isolate. In both prophylactic and therapeutic settings, SARS-CoV-2 remains undetectable in the lungs of treated hACE2 mice. Therapeutic treatment also causes a reduction in viral loads in the lungs of Syrian hamsters. When administered at 10 mg kg-1 one day prior to a high dose SARS-CoV-2 challenge in cynomolgus macaques, COVA1-18 shows very strong antiviral activity in the upper respiratory compartments. Using a mathematical model, we estimate that COVA1-18 reduces viral infectivity by more than 95% in these compartments, preventing lymphopenia and extensive lung lesions. Our findings demonstrate that COVA1-18 has a strong antiviral activity in three preclinical models and could be a valuable candidate for further clinical evaluation.


Subject(s)
Antibodies, Monoclonal/administration & dosage , Antibodies, Neutralizing/administration & dosage , Antiviral Agents/administration & dosage , COVID-19/drug therapy , SARS-CoV-2/immunology , Angiotensin-Converting Enzyme 2/genetics , Animals , Antibodies, Monoclonal/pharmacokinetics , Antiviral Agents/pharmacokinetics , COVID-19/blood , COVID-19/immunology , COVID-19/virology , Disease Models, Animal , Drug Evaluation, Preclinical , Female , Humans , Lung/metabolism , Lung/virology , Macaca fascicularis , Male , Mesocricetus , Mice , Mice, Transgenic , SARS-CoV-2/isolation & purification , Tissue Distribution , Viral Load
9.
EMBO J ; 40(20): e106765, 2021 10 18.
Article in English | MEDLINE | ID: covidwho-1436404

ABSTRACT

The current pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and outbreaks of new variants highlight the need for preventive treatments. Here, we identified heparan sulfate proteoglycans as attachment receptors for SARS-CoV-2. Notably, neutralizing antibodies against SARS-CoV-2 isolated from COVID-19 patients interfered with SARS-CoV-2 binding to heparan sulfate proteoglycans, which might be an additional mechanism of antibodies to neutralize infection. SARS-CoV-2 binding to and infection of epithelial cells was blocked by low molecular weight heparins (LMWH). Although dendritic cells (DCs) and mucosal Langerhans cells (LCs) were not infected by SARS-CoV-2, both DC subsets efficiently captured SARS-CoV-2 via heparan sulfate proteoglycans and transmitted the virus to ACE2-positive cells. Notably, human primary nasal cells were infected by SARS-CoV-2, and infection was blocked by pre-treatment with LMWH. These data strongly suggest that heparan sulfate proteoglycans are important attachment receptors facilitating infection and transmission, and support the use of LMWH as prophylaxis against SARS-CoV-2 infection.


Subject(s)
COVID-19/transmission , Heparan Sulfate Proteoglycans/metabolism , Heparin, Low-Molecular-Weight/pharmacology , SARS-CoV-2/pathogenicity , Angiotensin-Converting Enzyme 2/immunology , Angiotensin-Converting Enzyme 2/metabolism , Animals , Antibodies, Neutralizing/metabolism , Antibodies, Neutralizing/pharmacology , COVID-19/drug therapy , Chlorocebus aethiops , Dendritic Cells/metabolism , Dendritic Cells/virology , Epithelial Cells/metabolism , Epithelial Cells/virology , Host-Pathogen Interactions , Humans , Mucous Membrane/cytology , Mucous Membrane/virology , SARS-CoV-2/metabolism , Syndecan-1/metabolism , Syndecan-4/metabolism , Vero Cells
10.
Biochemistry ; 60(27): 2153-2169, 2021 07 13.
Article in English | MEDLINE | ID: covidwho-1387101

ABSTRACT

A central tenet in the design of vaccines is the display of native-like antigens in the elicitation of protective immunity. The abundance of N-linked glycans across the SARS-CoV-2 spike protein is a potential source of heterogeneity among the many different vaccine candidates under investigation. Here, we investigate the glycosylation of recombinant SARS-CoV-2 spike proteins from five different laboratories and compare them against S protein from infectious virus, cultured in Vero cells. We find patterns that are conserved across all samples, and this can be associated with site-specific stalling of glycan maturation that acts as a highly sensitive reporter of protein structure. Molecular dynamics simulations of a fully glycosylated spike support a model of steric restrictions that shape enzymatic processing of the glycans. These results suggest that recombinant spike-based SARS-CoV-2 immunogen glycosylation reproducibly recapitulates signatures of viral glycosylation.


Subject(s)
COVID-19/genetics , Protein Conformation , SARS-CoV-2/ultrastructure , Spike Glycoprotein, Coronavirus/ultrastructure , Animals , COVID-19/immunology , COVID-19/virology , COVID-19 Vaccines/genetics , COVID-19 Vaccines/immunology , Chlorocebus aethiops , Glycosylation , Humans , Molecular Dynamics Simulation , Protein Binding/genetics , SARS-CoV-2/genetics , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Vero Cells
11.
Cell Rep ; 33(3): 108274, 2020 10 20.
Article in English | MEDLINE | ID: covidwho-1385223

ABSTRACT

IGHV3-53-encoded neutralizing antibodies are commonly elicited during SARS-CoV-2 infection and target the receptor-binding domain (RBD) of the spike (S) protein. Such IGHV3-53 antibodies generally have a short CDR H3 because of structural constraints in binding the RBD (mode A). However, a small subset of IGHV3-53 antibodies to the RBD contain a longer CDR H3. Crystal structures of two IGHV3-53 neutralizing antibodies here demonstrate that a longer CDR H3 can be accommodated in a different binding mode (mode B). These two classes of IGHV3-53 antibodies both target the ACE2 receptor binding site, but with very different angles of approach and molecular interactions. Overall, these findings emphasize the versatility of IGHV3-53 in this common antibody response to SARS-CoV-2, where conserved IGHV3-53 germline-encoded features can be combined with very different CDR H3 lengths and light chains for SARS-CoV-2 RBD recognition and virus neutralization.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Betacoronavirus/immunology , Spike Glycoprotein, Coronavirus/immunology , COVID-19 , Complementarity Determining Regions/immunology , Coronavirus Infections/virology , Crystallography, X-Ray , Humans , Immunoglobulin Heavy Chains/immunology , Neutralization Tests , Pandemics , Pneumonia, Viral/virology , Protein Domains/immunology , SARS-CoV-2
12.
Pathog Immun ; 6(1): 116-134, 2021.
Article in English | MEDLINE | ID: covidwho-1389907

ABSTRACT

The approved Pfizer and Moderna mRNA vaccines are well known to induce serum antibody responses to the SARS-CoV-2 Spike (S)-protein. However, their abilities to elicit mucosal immune responses have not been reported. Saliva antibodies represent mucosal responses that may be relevant to how mRNA vaccines prevent oral and nasal SARS-CoV-2 transmission. Here, we describe the outcome of a cross-sectional study on a healthcare worker cohort (WELCOME-NYPH), in which we assessed whether IgM, IgG, and IgA antibodies to the S-protein and its receptor-binding domain (RBD) were present in serum and saliva samples. Anti-S-protein IgG was detected in 14/31 and 66/66 of saliva samples from uninfected participants after vaccine doses-1 and -2, respectively. IgA antibodies to the S-protein were present in 40/66 saliva samples after dose 2. Anti-S-protein IgG was present in every serum sample from recipients of 2 vaccine doses. Vaccine-induced antibodies against the RBD were also frequently present in saliva and sera. These findings may help our understanding of whether and how vaccines may impede SARS-CoV-2 transmission, including to oral cavity target cells.

13.
Biochemistry ; 60(27): 2153-2169, 2021 07 13.
Article in English | MEDLINE | ID: covidwho-1294429

ABSTRACT

A central tenet in the design of vaccines is the display of native-like antigens in the elicitation of protective immunity. The abundance of N-linked glycans across the SARS-CoV-2 spike protein is a potential source of heterogeneity among the many different vaccine candidates under investigation. Here, we investigate the glycosylation of recombinant SARS-CoV-2 spike proteins from five different laboratories and compare them against S protein from infectious virus, cultured in Vero cells. We find patterns that are conserved across all samples, and this can be associated with site-specific stalling of glycan maturation that acts as a highly sensitive reporter of protein structure. Molecular dynamics simulations of a fully glycosylated spike support a model of steric restrictions that shape enzymatic processing of the glycans. These results suggest that recombinant spike-based SARS-CoV-2 immunogen glycosylation reproducibly recapitulates signatures of viral glycosylation.


Subject(s)
COVID-19/genetics , Protein Conformation , SARS-CoV-2/ultrastructure , Spike Glycoprotein, Coronavirus/ultrastructure , Animals , COVID-19/immunology , COVID-19/virology , COVID-19 Vaccines/genetics , COVID-19 Vaccines/immunology , Chlorocebus aethiops , Glycosylation , Humans , Molecular Dynamics Simulation , Protein Binding/genetics , SARS-CoV-2/genetics , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Vero Cells
14.
Nutrients ; 13(5)2021 May 13.
Article in English | MEDLINE | ID: covidwho-1227048

ABSTRACT

BACKGROUND: Since the outbreak of coronavirus disease 2019 (COVID-19), many put their hopes in the rapid availability of effective immunizations. Human milk, containing antibodies against syndrome coronavirus 2 (SARS-CoV-2), may serve as means of protection through passive immunization. We aimed to determine the presence and pseudovirus neutralization capacity of SARS-CoV-2 specific IgA in human milk of mothers who recovered from COVID-19, and the effect of pasteurization on these antibodies. METHODS: This prospective case control study included lactating mothers, recovered from (suspected) COVID-19 and healthy controls. Human milk and serum samples were collected. To assess the presence of SARS-CoV-2 antibodies we used multiple complementary assays, namely ELISA with the SARS-CoV-2 spike protein (specific for IgA and IgG), receptor binding domain (RBD) and nucleocapsid (N) protein for IgG in serum, and bridging ELISA with the SARS-CoV-2 RBD and N protein for specific Ig (IgG, IgM and IgA in human milk and serum). To assess the effect of pasteurization, human milk was exposed to Holder (HoP) and High Pressure Pasteurization (HPP). RESULTS: Human milk contained abundant SARS-CoV-2 antibodies in 83% of the proven cases and in 67% of the suspected cases. Unpasteurized milk with and without these antibodies was found to be capable of neutralizing a pseudovirus of SARS-CoV-2 in (97% and 85% of the samples respectively). After pasteurization, total IgA antibody levels were affected by HoP, while SARS-CoV-2 specific antibody levels were affected by HPP. Pseudovirus neutralizing capacity of the human milk samples was only retained with the HPP approach. No correlation was observed between milk antibody levels and neutralization capacity. CONCLUSIONS: Human milk from recovered COVID-19-infected mothers contains SARS-CoV-2 specific antibodies which maintained neutralization capacity after HPP. All together this may represent a safe and effective immunization strategy after HPP.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/immunology , Lactation , Milk, Human/immunology , Pasteurization , SARS-CoV-2/immunology , Adult , Female , Humans
15.
Sci Transl Med ; 13(596)2021 06 02.
Article in English | MEDLINE | ID: covidwho-1225692

ABSTRACT

Patients diagnosed with coronavirus disease 2019 (COVID-19) become critically ill primarily around the time of activation of the adaptive immune response. Here, we provide evidence that antibodies play a role in the worsening of disease at the time of seroconversion. We show that early-phase severe acute respiratory distress syndrome coronavirus 2 (SARS-CoV-2) spike protein-specific immunoglobulin G (IgG) in serum of critically ill COVID-19 patients induces excessive inflammatory responses by human alveolar macrophages. We identified that this excessive inflammatory response is dependent on two antibody features that are specific for patients with severe COVID-19. First, inflammation is driven by high titers of anti-spike IgG, a hallmark of severe disease. Second, we found that anti-spike IgG from patients with severe COVID-19 is intrinsically more proinflammatory because of different glycosylation, particularly low fucosylation, of the antibody Fc tail. Low fucosylation of anti-spike IgG was normalized in a few weeks after initial infection with SARS-CoV-2, indicating that the increased antibody-dependent inflammation mainly occurs at the time of seroconversion. We identified Fcγ receptor (FcγR) IIa and FcγRIII as the two primary IgG receptors that are responsible for the induction of key COVID-19-associated cytokines such as interleukin-6 and tumor necrosis factor. In addition, we show that anti-spike IgG-activated human macrophages can subsequently break pulmonary endothelial barrier integrity and induce microvascular thrombosis in vitro. Last, we demonstrate that the inflammatory response induced by anti-spike IgG can be specifically counteracted by fostamatinib, an FDA- and EMA-approved therapeutic small-molecule inhibitor of Syk kinase.


Subject(s)
Antibodies, Viral/chemistry , COVID-19/immunology , Immunoglobulin G/chemistry , Macrophages, Alveolar/immunology , Glycosylation , Humans , Inflammation , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/immunology
16.
Science ; 371(6532)2021 02 26.
Article in English | MEDLINE | ID: covidwho-1066801

ABSTRACT

Immunoglobulin G (IgG) antibodies are crucial for protection against invading pathogens. A highly conserved N-linked glycan within the IgG-Fc tail, which is essential for IgG function, shows variable composition in humans. Afucosylated IgG variants are already used in anticancer therapeutic antibodies for their increased activity through Fc receptors (FcγRIIIa). Here, we report that afucosylated IgG (approximately 6% of total IgG in humans) are specifically formed against enveloped viruses but generally not against other antigens. This mediates stronger FcγRIIIa responses but also amplifies brewing cytokine storms and immune-mediated pathologies. Critically ill COVID-19 patients, but not those with mild symptoms, had high concentrations of afucosylated IgG antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), amplifying proinflammatory cytokine release and acute phase responses. Thus, antibody glycosylation plays a critical role in immune responses to enveloped viruses, including COVID-19.


Subject(s)
Antibodies, Viral/immunology , COVID-19/immunology , Immunoglobulin G/immunology , SARS-CoV-2/immunology , Adult , Aged , Antibodies, Viral/blood , Antibodies, Viral/chemistry , COVID-19/physiopathology , Cells, Cultured , Critical Illness , Cytomegalovirus/immunology , Female , Fucose/analysis , Glycosylation , HIV/immunology , Hepatitis B Vaccines/immunology , Humans , Immunoglobulin Fc Fragments/chemistry , Immunoglobulin Fc Fragments/immunology , Immunoglobulin G/blood , Immunoglobulin G/chemistry , Inflammation , Interleukin-6/biosynthesis , Interleukin-6/immunology , Macrophages/immunology , Male , Middle Aged , Parvovirus B19, Human/immunology , Severity of Illness Index , Spike Glycoprotein, Coronavirus/immunology , Vaccines, Subunit/immunology , Young Adult
17.
Cell ; 184(5): 1188-1200.e19, 2021 03 04.
Article in English | MEDLINE | ID: covidwho-1046538

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic is continuing to disrupt personal lives, global healthcare systems, and economies. Hence, there is an urgent need for a vaccine that prevents viral infection, transmission, and disease. Here, we present a two-component protein-based nanoparticle vaccine that displays multiple copies of the SARS-CoV-2 spike protein. Immunization studies show that this vaccine induces potent neutralizing antibody responses in mice, rabbits, and cynomolgus macaques. The vaccine-induced immunity protects macaques against a high-dose challenge, resulting in strongly reduced viral infection and replication in the upper and lower airways. These nanoparticles are a promising vaccine candidate to curtail the SARS-CoV-2 pandemic.


Subject(s)
COVID-19 Vaccines/administration & dosage , COVID-19 Vaccines/immunology , Macaca fascicularis , Spike Glycoprotein, Coronavirus/chemistry , Animals , Antibodies, Neutralizing , B-Lymphocytes/immunology , COVID-19/immunology , COVID-19/prevention & control , Mice , Mice, Inbred BALB C , Models, Animal , Nanoparticles/administration & dosage , Rabbits , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/blood , T-Lymphocytes/immunology , Viral Load
18.
Immunity ; 53(6): 1272-1280.e5, 2020 12 15.
Article in English | MEDLINE | ID: covidwho-967824

ABSTRACT

Most antibodies isolated from individuals with coronavirus disease 2019 (COVID-19) are specific to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, COVA1-16 is a relatively rare antibody that also cross-neutralizes SARS-CoV. Here, we determined a crystal structure of the COVA1-16 antibody fragment (Fab) with the SARS-CoV-2 receptor-binding domain (RBD) and negative-stain electron microscopy reconstructions with the spike glycoprotein trimer to elucidate the structural basis of its cross-reactivity. COVA1-16 binds a highly conserved epitope on the SARS-CoV-2 RBD, mainly through a long complementarity-determining region (CDR) H3, and competes with the angiotensin-converting enzyme 2 (ACE2) receptor because of steric hindrance rather than epitope overlap. COVA1-16 binds to a flexible up conformation of the RBD on the spike and relies on antibody avidity for neutralization. These findings, along with the structural and functional rationale for epitope conservation, provide insights for development of more universal SARS-like coronavirus vaccines and therapies.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , Antibodies, Viral/metabolism , COVID-19 Vaccines/immunology , COVID-19/immunology , SARS Virus/immunology , SARS-CoV-2/immunology , Antibodies, Viral/genetics , Broadly Neutralizing Antibodies/genetics , Broadly Neutralizing Antibodies/metabolism , Conserved Sequence/genetics , Cross Reactions , Crystallization , Epitope Mapping , Epitopes, B-Lymphocyte/genetics , Epitopes, B-Lymphocyte/metabolism , Humans , Immunoglobulin Fab Fragments/genetics , Immunoglobulin Fab Fragments/metabolism , Protein Binding , Protein Conformation , Protein Interaction Domains and Motifs/genetics
20.
Science ; 369(6504): 643-650, 2020 08 07.
Article in English | MEDLINE | ID: covidwho-599037

ABSTRACT

The rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has had a large impact on global health, travel, and economy. Therefore, preventative and therapeutic measures are urgently needed. Here, we isolated monoclonal antibodies from three convalescent coronavirus disease 2019 (COVID-19) patients using a SARS-CoV-2 stabilized prefusion spike protein. These antibodies had low levels of somatic hypermutation and showed a strong enrichment in VH1-69, VH3-30-3, and VH1-24 gene usage. A subset of the antibodies was able to potently inhibit authentic SARS-CoV-2 infection at a concentration as low as 0.007 micrograms per milliliter. Competition and electron microscopy studies illustrate that the SARS-CoV-2 spike protein contains multiple distinct antigenic sites, including several receptor-binding domain (RBD) epitopes as well as non-RBD epitopes. In addition to providing guidance for vaccine design, the antibodies described here are promising candidates for COVID-19 treatment and prevention.


Subject(s)
Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Betacoronavirus/immunology , Coronavirus Infections/immunology , Pneumonia, Viral/immunology , Spike Glycoprotein, Coronavirus/immunology , Adult , Aged , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Antibody Affinity , Antigens, Viral/immunology , B-Lymphocyte Subsets/immunology , Broadly Neutralizing Antibodies/immunology , COVID-19 , Cell Line, Tumor , Coronavirus Infections/prevention & control , Coronavirus Infections/therapy , Epitopes/immunology , Female , Humans , Immunologic Memory , Immunophenotyping , Male , Middle Aged , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Pneumonia, Viral/therapy , Protein Domains , Protein Interaction Domains and Motifs/immunology , Receptors, Coronavirus , Receptors, Virus/metabolism , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/chemistry
SELECTION OF CITATIONS
SEARCH DETAIL