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1.
Front Immunol ; 12: 707977, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34621266

RESUMO

The ongoing COVID-19 pandemic caused by SARS-CoV-2 is a huge public health crisis for the globe. The receptor-binding domain (RBD) of SARS-CoV-2 spike (S) protein plays a vital role in viral infection and serves as a major target for developing neutralizing antibodies. In this study, the antibody response to the RBD of SARS-CoV-2 S protein was analyzed by a panel of sera from animals immunized with RBD-based antigens and four linear B-cell epitope peptides (R345, R405, R450 and R465) were revealed. The immunogenicity of three immunodominant peptides (R345, R405, R465) was further accessed by peptide immunization in mice, and all of them could induced potent antibody response to SARS-CoV-2 S protein, indicating that the three determinants in the RBD were immunogenic. We further generated and characterized monoclonal antibodies (15G9, 12C10 and 10D2) binding to these epitope peptides, and finely mapped the three immunodominant epitopes using the corresponding antibodies. Neutralization assays showed that all three monoclonal antibodies had neutralization activity. Results from IFA and western blotting showed that 12C10 was a cross-reactive antibody against both of SARS-CoV-2 and SARS-CoV. Results from conservative and structural analysis showed that 350VYAWN354 was a highly conserved epitope and exposed on the surface of SARS-CoV-2 S trimer, whereas 473YQAGSTP479 located in the receptor binding motif (RBM) was variable among different SARS-CoV-2 strains. 407VRQIAP412 was a highly conserved, but cryptic epitope shared between SARS-CoV-2 and SARS-CoV. These findings provide important information for understanding the humoral antibody response to the RBD of SARS-CoV-2 S protein and may facilitate further efforts to design SARS-CoV-2 vaccines and the target of COVID-19 diagnostic.


Assuntos
Linfócitos B/imunologia , Epitopos de Linfócito B/metabolismo , Peptídeos/metabolismo , Glicoproteína da Espícula de Coronavírus/metabolismo , Motivos de Aminoácidos/genética , Anticorpos Monoclonais/metabolismo , Anticorpos Neutralizantes/metabolismo , Anticorpos Antivirais/metabolismo , Vacinas contra COVID-19 , Sequência Conservada/genética , Mapeamento de Epitopos , Epitopos de Linfócito B/genética , Células HEK293 , Humanos , Imunidade Humoral , Peptídeos/genética , Ligação Proteica , Glicoproteína da Espícula de Coronavírus/genética
2.
Front Immunol ; 12: 730404, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34621274

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus causes a spectrum of clinical manifestations, ranging from asymptomatic to mild, moderate, or severe illness with multi-organ failure and death. Using a new machine learning algorithm developed by us, we have reported a significantly higher number of predicted COVID-19 cases than the documented counts across the world. The sole reliance on confirmed symptomatic cases overlooking the symptomless COVID-19 infections and the dynamics of waning immunity may not provide 'true' spectrum of infection proportion, a key element for an effective planning and implementation of protection and prevention strategies. We and others have previously shown that strategic orthogonal testing and leveraging systematic data-driven modeling approach to account for asymptomatics and waning cases may situationally have a compelling role in informing efficient vaccination strategies beyond prevalence reporting. However, currently Centers for Disease Control and Prevention (CDC) does not recommend serological testing either before or after vaccination to assess immune status. Given the 27% occurrence of breakthrough infections in fully vaccinated (FV) group with many being asymptomatics and still a larger fraction of the general mass remaining unvaccinated, the relaxed mask mandate and distancing by CDC can drive resurgence. Thus, we believe it is a key time to focus on asymptomatics (no symptoms) and oligosymptomatics (so mild that the symptoms remain unrecognized) as they can be silent reservoirs to propagate the infection. This perspective thus highlights the need for proactive efforts to reevaluate the current variables/strategies in accounting for symptomless and waning fractions.


Assuntos
Vacinas contra COVID-19/imunologia , COVID-19/imunologia , SARS-CoV-2/fisiologia , Anticorpos Neutralizantes/metabolismo , Anticorpos Antivirais/metabolismo , Doenças Assintomáticas , COVID-19/transmissão , Teste Sorológico para COVID-19 , Centers for Disease Control and Prevention, U.S. , Humanos , Imunidade , Estados Unidos , Vacinação
3.
Front Immunol ; 12: 730766, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34630410

RESUMO

The SARS-CoV-2 pandemic has spread to all parts of the world and can cause life-threatening pneumonia and other severe disease manifestations known as COVID-19. This health crisis has resulted in a significant effort to stop the spread of this new coronavirus. However, while propagating itself in the human population, the virus accumulates mutations and generates new variants with increased fitness and the ability to escape the human immune response. Here we describe a color-based barcoded spike flow cytometric assay (BSFA) that is particularly useful to evaluate and directly compare the humoral immune response directed against either wild type (WT) or mutant spike (S) proteins or the receptor-binding domains (RBD) of SARS-CoV-2. This assay employs the human B lymphoma cell line Ramos, transfected for stable expression of WT or mutant S proteins or a chimeric RBD-CD8 fusion protein. We find that the alpha and beta mutants are more stably expressed than the WT S protein on the Ramos B cell surface and/or bind with higher affinity to the viral entry receptor ACE2. However, we find a reduce expression of the chimeric RBD-CD8 carrying the point mutation N501Y and E484K characteristic for the alpha and beta variant, respectively. The comparison of the humoral immune response of 12 vaccinated probands with 12 COVID-19 patients shows that after the boost, the S-specific IgG class immune response in the vaccinated group is similar to that of the patient group. However, in comparison to WT the specific IgG serum antibodies bind less well to the alpha variant and only poorly to the beta variant S protein. This is in line with the notion that the beta variant is an immune escape variant of SARS-CoV-2. The IgA class immune response was more variable than the IgG response and higher in the COVID-19 patients than in the vaccinated group. In summary, we think that our BSFA represents a useful tool to evaluate the humoral immunity against emerging variants of SARS-CoV-2 and to analyze new vaccination protocols against these variants.


Assuntos
COVID-19/imunologia , Separação Celular/métodos , Citometria de Fluxo/métodos , SARS-CoV-2/fisiologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Enzima de Conversão de Angiotensina 2/metabolismo , Anticorpos Antivirais/metabolismo , Formação de Anticorpos , Feminino , Humanos , Imunização Secundária , Imunoglobulina A/metabolismo , Imunoglobulina G/metabolismo , Masculino , Pessoa de Meia-Idade , Mutação/genética , Glicoproteína da Espícula de Coronavírus/genética , Vacinação
4.
Front Immunol ; 12: 751584, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34630430

RESUMO

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic of novel coronavirus disease (COVID-19). Though vaccines and neutralizing monoclonal antibodies (mAbs) have been developed to fight COVID-19 in the past year, one major concern is the emergence of SARS-CoV-2 variants of concern (VOCs). Indeed, SARS-CoV-2 VOCs such as B.1.1.7 (UK), B.1.351 (South Africa), P.1 (Brazil), and B.1.617.1 (India) now dominate the pandemic. Herein, we found that binding activity and neutralizing capacity of sera collected from convalescent patients in early 2020 for SARS-CoV-2 VOCs, but not non-VOC variants, were severely blunted. Furthermore, we observed evasion of SARS-CoV-2 VOCs from a VH3-30 mAb 32D4, which was proved to exhibit highly potential neutralization against wild-type (WT) SARS-CoV-2. Thus, these results indicated that SARS-CoV-2 VOCs might be able to spread in convalescent patients and even harbor resistance to medical countermeasures. New interventions against these SARS-CoV-2 VOCs are urgently needed.


Assuntos
COVID-19/imunologia , Mutação/genética , SARS-CoV-2/fisiologia , Adulto , Anticorpos Monoclonais/metabolismo , Anticorpos Neutralizantes/metabolismo , Anticorpos Antivirais/metabolismo , COVID-19/genética , COVID-19/terapia , Feminino , Humanos , Evasão da Resposta Imune , Imunização Passiva , Masculino , Pessoa de Meia-Idade , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo
5.
Front Immunol ; 12: 757691, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34630436

RESUMO

The increase in confirmed COVID-19 cases and SARS-CoV-2 variants calls for the development of safe and broad cross-protective vaccines. The RBD of the spike protein was considered to be a safe and effective candidate antigen. However, the low immunogenicity limited its application in vaccine development. Herein, we designed and obtained an RBD heptamer (mHla-RBD) based on a carrier protein-aided assembly strategy. The molecular weight of mHla-RBD is up to 450 kDa, approximately 10 times higher than that of the RBD monomer. When formulated with alum adjuvant, mHla-RBD immunization significantly increased the immunogenicity of RBD, as indicated by increased titers of RBD-specific antibodies, neutralizing antibodies, Th2 cellular immune response, and pseudovirus neutralization activity, when compared to RBD monomer. Furthermore, we confirmed that RBD-specific antibodies predominantly target conformational epitopes, which was approximately 200 times that targeting linear epitopes. Finally, a pseudovirus neutralization assay revealed that neutralizing antibodies induced by mHla-RBD against different SARS-CoV-2 variants were comparable to those against the wild-type virus and showed broad-spectrum neutralizing activity toward different SARS-CoV-2 variants. Our results demonstrated that mHla-RBD is a promising candidate antigen for development of SARS-CoV-2 vaccines and the mHla could serve as a universal carrier protein for antigen design.


Assuntos
Proteínas de Bactérias/metabolismo , Vacinas contra COVID-19/imunologia , COVID-19/imunologia , Proteínas de Transporte/metabolismo , Proteínas Hemolisinas/metabolismo , SARS-CoV-2/fisiologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Células Th2/imunologia , Animais , Anticorpos Neutralizantes/metabolismo , Anticorpos Antivirais/metabolismo , Anticorpos Amplamente Neutralizantes/metabolismo , Linhagem Celular , Proteínas de Escherichia coli , Humanos , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Domínios Proteicos/genética , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia
6.
Clin Immunol ; 231: 108850, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34506944

RESUMO

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, has resulted in considerable morbidity and mortality in humans. Little is known regarding the development of immunological memory following SARS-CoV-2 infection or whether immunological memory can provide long-lasting protection against reinfection. Urgent need for vaccines is a considerable issue for all governments worldwide. METHODS: A total of 39 patients were recruited in this study. Tonsillar mononuclear cells (MNCs) were co-cultured in RPMI medium and stimulated with the full-length SARS-CoV-2 spike protein in the presence and absence of a CpG-DNA adjuvant. An enzyme-linked immunosorbent assay (ELISA) was utilised to measure the specific antibody response to the spike protein in the cell culture supernatants. RESULTS: The SARS-CoV-2 spike protein primed a potent memory B cell-mediated immune response in nasal-associated lymphoid tissue (NALT) from patients previously infected with the virus. Additionally, spike protein combined with the CpG-DNA adjuvant induced a significantly increased level of specific anti-spike protein IgG antibody compared with the spike protein alone (p < 0.0001, n = 24). We also showed a strong positive correlation between the specific anti-spike protein IgG antibody level in a serum samples and that produced by MNCs derived from the same COVID-19-recovered patients following stimulation (r = 0.76, p = 0.0002, n = 24). CONCLUSION: Individuals with serological evidence of previous SARS-CoV-2 exposure showed a significant anti-spike protein-specific memory humoral immune response to the viral spike protein upon stimulation. Additionally, our results demonstrated the functional response of NALT-derived MNCs to the viral spike protein. CpG-DNA adjuvant combined with spike protein induced significantly stronger humoral immune responses than the spike protein alone. These data indicate that the S protein antigen combined with CpG-DNA adjuvant could be used as a future vaccine candidate.


Assuntos
COVID-19/imunologia , COVID-19/virologia , Memória Imunológica/fisiologia , Tecido Linfoide/fisiologia , SARS-CoV-2/imunologia , Anticorpos Antivirais/metabolismo , Linfócitos B , Células Cultivadas , DNA , Ensaio de Imunoadsorção Enzimática , Humanos , Imunidade Celular , Imunidade Humoral , Imunoglobulina G/metabolismo , Tecido Linfoide/virologia , Nariz , Oligodesoxirribonucleotídeos , Glicoproteína da Espícula de Coronavírus/imunologia
7.
BMC Pregnancy Childbirth ; 21(1): 632, 2021 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-34535094

RESUMO

BACKGROUND: Immunological protection via breastfeeding is well known. The immunological profile of human milk changes during lactation. No clinical trials have been conducted in lactating women with the newest mRNA vaccines against SARS- CoV-2. A Few studies have shown the presence of antibodies in breastmilk after vaccination. The aim of this work is to study possible antibodies transfer via breastmilk and also the immunological characteristics of lactating women compared to non-lactating women, after using the BNT162b2 Pfizer vaccine. METHODS: This is a prospective cohort study with a convenience homogenous sample of 24 healthcare workers (14 lactating and 10 non-lactating women) enrolled at the time of COVID-19 vaccination. Clinical data was registered in a questionnaire. Titers of SARS-CoV-2 spike IgG, IgA and IgM were quantified in post vaccination blood and human milk. Antibody quantification was performed by an in-house ELISA to SARS-CoV-2 trimeric spike protein. RESULTS: All women showed immunity after vaccination with positive antibodies for IgM, IgA and IgG antibodies. The dominant serum antibody response was IgG. Modest levels of antibodies in breastmilk of lactating mothers were observed in this study, especially IgG in 42.9%. There was a moderate association between higher titers of IgG and a longer duration of breastfeeding (R= 0.55, p=0.041). CONCLUSIONS: Evidence of antibody transfer in human milk after COVID-19 vaccination is scarce. The presence of antibodies in human milk is reported, but immunization through breastfeeding is still to be established.


Assuntos
Anticorpos Antivirais/metabolismo , Aleitamento Materno , Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , Lactação/imunologia , Leite Humano/imunologia , SARS-CoV-2/imunologia , Adulto , Biomarcadores/metabolismo , COVID-19/imunologia , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunização Passiva , Estudos Prospectivos
8.
Signal Transduct Target Ther ; 6(1): 343, 2021 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-34531369

RESUMO

SARS-CoV-2 recognizes, via its spike receptor-binding domain (S-RBD), human angiotensin-converting enzyme 2 (ACE2) to initiate infection. Ecto-domain protein of ACE2 can therefore function as a decoy. Here we show that mutations of S19W, T27W, and N330Y in ACE2 could individually enhance SARS-CoV-2 S-RBD binding. Y330 could be synergistically combined with either W19 or W27, whereas W19 and W27 are mutually unbeneficial. The structures of SARS-CoV-2 S-RBD bound to the ACE2 mutants reveal that the enhanced binding is mainly contributed by the van der Waals interactions mediated by the aromatic side-chains from W19, W27, and Y330. While Y330 and W19/W27 are distantly located and devoid of any steric interference, W19 and W27 are shown to orient their side-chains toward each other and to cause steric conflicts, explaining their incompatibility. Finally, using pseudotyped SARS-CoV-2 viruses, we demonstrate that these residue substitutions are associated with dramatically improved entry-inhibition efficacy toward both wild-type and antibody-resistant viruses. Taken together, our biochemical and structural data have delineated the basis for the elevated S-RBD binding associated with S19W, T27W, and N330Y mutations in ACE2, paving the way for potential application of these mutants in clinical treatment of COVID-19.


Assuntos
Enzima de Conversão de Angiotensina 2/química , COVID-19 , Simulação de Dinâmica Molecular , Mutação de Sentido Incorreto , SARS-CoV-2/química , Substituição de Aminoácidos , Enzima de Conversão de Angiotensina 2/genética , Enzima de Conversão de Angiotensina 2/metabolismo , Anticorpos Antivirais/química , Anticorpos Antivirais/metabolismo , Humanos , SARS-CoV-2/genética , SARS-CoV-2/metabolismo
9.
Mol Syst Biol ; 17(9): e10243, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34487431

RESUMO

Systems serology provides a broad view of humoral immunity by profiling both the antigen-binding and Fc properties of antibodies. These studies contain structured biophysical profiling across disease-relevant antigen targets, alongside additional measurements made for single antigens or in an antigen-generic manner. Identifying patterns in these measurements helps guide vaccine and therapeutic antibody development, improve our understanding of diseases, and discover conserved regulatory mechanisms. Here, we report that coupled matrix-tensor factorization (CMTF) can reduce these data into consistent patterns by recognizing the intrinsic structure of these data. We use measurements from two previous studies of HIV- and SARS-CoV-2-infected subjects as examples. CMTF outperforms standard methods like principal components analysis in the extent of data reduction while maintaining equivalent prediction of immune functional responses and disease status. Under CMTF, model interpretation improves through effective data reduction, separation of the Fc and antigen-binding effects, and recognition of consistent patterns across individual measurements. Data reduction also helps make prediction models more replicable. Therefore, we propose that CMTF is an effective general strategy for data exploration in systems serology.


Assuntos
Sorodiagnóstico da AIDS , Teste Sorológico para COVID-19 , COVID-19/imunologia , Interpretação Estatística de Dados , Infecções por HIV/imunologia , Sorodiagnóstico da AIDS/métodos , Sorodiagnóstico da AIDS/estatística & dados numéricos , Anticorpos Antivirais/sangue , Anticorpos Antivirais/metabolismo , Teste Sorológico para COVID-19/métodos , Teste Sorológico para COVID-19/estatística & dados numéricos , Humanos , Imunidade Humoral , Células Matadoras Naturais/imunologia , Modelos Logísticos , Receptores Fc/imunologia , Receptores de IgG/imunologia
10.
PLoS Comput Biol ; 17(9): e1009380, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34491988

RESUMO

The SARS-CoV-2 pandemic highlights the need for a detailed molecular understanding of protective antibody responses. This is underscored by the emergence and spread of SARS-CoV-2 variants, including Alpha (B.1.1.7) and Delta (B.1.617.2), some of which appear to be less effectively targeted by current monoclonal antibodies and vaccines. Here we report a high resolution and comprehensive map of antibody recognition of the SARS-CoV-2 spike receptor binding domain (RBD), which is the target of most neutralizing antibodies, using computational structural analysis. With a dataset of nonredundant experimentally determined antibody-RBD structures, we classified antibodies by RBD residue binding determinants using unsupervised clustering. We also identified the energetic and conservation features of epitope residues and assessed the capacity of viral variant mutations to disrupt antibody recognition, revealing sets of antibodies predicted to effectively target recently described viral variants. This detailed structure-based reference of antibody RBD recognition signatures can inform therapeutic and vaccine design strategies.


Assuntos
Anticorpos Antivirais , COVID-19/virologia , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus , Anticorpos Antivirais/química , Anticorpos Antivirais/metabolismo , Sítios de Ligação , Análise por Conglomerados , Biologia Computacional , Humanos , Modelos Moleculares , Ligação Proteica , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/metabolismo
11.
Front Immunol ; 12: 636966, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34557180

RESUMO

Since 2003, the world has been confronted with three new betacoronaviruses that cause human respiratory infections: SARS-CoV, which causes severe acute respiratory syndrome (SARS), MERS-CoV, which causes Middle East respiratory syndrome (MERS), and SARS-CoV-2, which causes Coronavirus Disease 2019 (COVID-19). The mechanisms of coronavirus transmission and dissemination in the human body determine the diagnostic and therapeutic strategies. An important problem is the possibility that viral particles overcome tissue barriers such as the intestine, respiratory tract, blood-brain barrier, and placenta. In this work, we will 1) consider the issue of endocytosis and the possibility of transcytosis and paracellular trafficking of coronaviruses across tissue barriers with an emphasis on the intestinal epithelium; 2) discuss the possibility of antibody-mediated transcytosis of opsonized viruses due to complexes of immunoglobulins with their receptors; 3) assess the possibility of the virus transfer into extracellular vesicles during intracellular transport; and 4) describe the clinical significance of these processes. Models of the intestinal epithelium and other barrier tissues for in vitro transcytosis studies will also be briefly characterized.


Assuntos
Endocitose , Mucosa Intestinal/virologia , SARS-CoV-2/metabolismo , Anticorpos Antivirais/metabolismo , Antivirais/farmacologia , Antivirais/uso terapêutico , COVID-19/tratamento farmacológico , COVID-19/transmissão , COVID-19/virologia , Ensaios Clínicos como Assunto , Endocitose/efeitos dos fármacos , Humanos , Mucosa Intestinal/metabolismo , Modelos Biológicos , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/imunologia , Junções Íntimas/metabolismo , Junções Íntimas/virologia , Transcitose/efeitos dos fármacos , Ligação Viral
12.
Blood Cancer J ; 11(9): 151, 2021 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-34521813

RESUMO

The ability of patients with hematologic malignancies (HM) to develop an effective humoral immune response after COVID-19 is unknown. A prospective study was performed to monitor the immune response to SARS-CoV-2 of patients with follicular lymphoma (FL), diffuse large B-cell lymphoma (DLBCL), chronic lymphoproliferative disorders (CLD), multiple myeloma (MM), or myelodysplastic/myeloproliferative syndromes (MDS/MPN). Antibody (Ab) levels to the SARS-CoV-2 nucleocapsid (N) and spike (S) protein were measured at +1, +3, +6 months after nasal swabs became PCR-negative. Forty-five patients (9 FL, 8 DLBCL, 8 CLD, 10 MM, 10 MDS/MPS) and 18 controls were studied. Mean anti-N and anti-S-Ab levels were similar between HM patients and controls, and shared the same behavior, with anti-N Ab levels declining at +6 months and anti-S-Ab remaining stable. Seroconversion rates were lower in HM patients than in controls. In lymphoma patients mean Ab levels and seroconversion rates were lower than in other HM patients, primarily because all nine patients who had received rituximab within 6 months before COVID-19 failed to produce anti-N and anti-S-Ab. Only one patient requiring hematological treatment after COVID-19 lost seropositivity after 6 months. No reinfections were observed. These results may inform vaccination policies and clinical management of HM patients.


Assuntos
COVID-19/imunologia , Neoplasias Hematológicas/imunologia , Imunidade Humoral/efeitos dos fármacos , Rituximab/farmacologia , SARS-CoV-2/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/efeitos dos fármacos , Anticorpos Antivirais/metabolismo , Formação de Anticorpos/efeitos dos fármacos , Formação de Anticorpos/fisiologia , Especificidade de Anticorpos/efeitos dos fármacos , COVID-19/complicações , COVID-19/epidemiologia , COVID-19/terapia , Estudos de Casos e Controles , Feminino , Seguimentos , Neoplasias Hematológicas/complicações , Neoplasias Hematológicas/tratamento farmacológico , Neoplasias Hematológicas/epidemiologia , Hospitalização , Humanos , Itália/epidemiologia , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Rituximab/uso terapêutico
13.
Nat Commun ; 12(1): 5621, 2021 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-34556667

RESUMO

Although serological studies have shown that antibodies against SARS-CoV-2 play an important role in protection against (re)infection, the dynamics of mucosal antibodies during primary infection and their potential impact on viral load and the resolution of disease symptoms remain unclear. During the first pandemic wave, we assessed the longitudinal nasal antibody response in index cases with mild COVID-19 and their household contacts. Nasal and serum antibody responses were analysed for up to nine months. Higher nasal receptor binding domain and spike protein-specific antibody levels at study inclusion were associated with lower viral load. Older age was correlated with more frequent COVID-19 related symptoms. Receptor binding domain and spike protein-specific mucosal antibodies were associated with the resolution of systemic, but not respiratory symptoms. Finally, receptor binding domain and spike protein-specific mucosal antibodies remained elevated up to nine months after symptom onset.


Assuntos
Anticorpos Neutralizantes/análise , Anticorpos Antivirais/análise , COVID-19/diagnóstico , Mucosa Nasal/metabolismo , SARS-CoV-2/imunologia , Adolescente , Adulto , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/metabolismo , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/metabolismo , COVID-19/sangue , COVID-19/imunologia , COVID-19/virologia , Teste Sorológico para COVID-19/estatística & dados numéricos , Criança , Humanos , Imunidade nas Mucosas , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Mucosa Nasal/imunologia , Mucosa Nasal/virologia , Índice de Gravidade de Doença , Carga Viral , Adulto Jovem
14.
Nat Commun ; 12(1): 5652, 2021 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-34580306

RESUMO

The emergence of numerous variants of SARS-CoV-2, the causative agent of COVID-19, has presented new challenges to the global efforts to control the COVID-19 pandemic. Here, we obtain two cross-neutralizing antibodies (7D6 and 6D6) that target Sarbecoviruses' receptor-binding domain (RBD) with sub-picomolar affinities and potently neutralize authentic SARS-CoV-2. Crystal structures show that both antibodies bind a cryptic site different from that recognized by existing antibodies and highly conserved across Sarbecovirus isolates. Binding of these two antibodies to the RBD clashes with the adjacent N-terminal domain and disrupts the viral spike. Both antibodies confer good resistance to mutations in the currently circulating SARS-CoV-2 variants. Thus, our results have direct relevance to public health as options for passive antibody therapeutics and even active prophylactics. They can also inform the design of pan-sarbecovirus vaccines.


Assuntos
Anticorpos Antivirais/imunologia , Anticorpos Amplamente Neutralizantes/imunologia , COVID-19/terapia , Imunização Passiva/métodos , SARS-CoV-2/imunologia , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/isolamento & purificação , Anticorpos Monoclonais/metabolismo , Anticorpos Antivirais/administração & dosagem , Anticorpos Antivirais/isolamento & purificação , Anticorpos Antivirais/metabolismo , Sítios de Ligação/genética , Sítios de Ligação/imunologia , Anticorpos Amplamente Neutralizantes/administração & dosagem , Anticorpos Amplamente Neutralizantes/isolamento & purificação , Anticorpos Amplamente Neutralizantes/metabolismo , Células CHO , COVID-19/epidemiologia , COVID-19/imunologia , COVID-19/virologia , Chlorocebus aethiops , Cricetulus , Epitopos/imunologia , Células HEK293 , Humanos , Camundongos , Coronavírus da Síndrome Respiratória do Oriente Médio/genética , Coronavírus da Síndrome Respiratória do Oriente Médio/imunologia , Testes de Neutralização , Pandemias/prevenção & controle , Multimerização Proteica , Receptores Virais/metabolismo , SARS-CoV-2/genética , Células Sf9 , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Células Vero
15.
Int J Mol Sci ; 22(17)2021 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-34502041

RESUMO

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) outbreak in December 2019 has caused a global pandemic. The rapid mutation rate in the virus has created alarming situations worldwide and is being attributed to the false negativity in RT-PCR tests. It has also increased the chances of reinfection and immune escape. Recently various lineages namely, B.1.1.7 (Alpha), B.1.617.1 (Kappa), B.1.617.2 (Delta) and B.1.617.3 have caused rapid infection around the globe. To understand the biophysical perspective, we have performed molecular dynamic simulations of four different spikes (receptor binding domain)-hACE2 complexes, namely wildtype (WT), Alpha variant (N501Y spike mutant), Kappa (L452R, E484Q) and Delta (L452R, T478K), and compared their dynamics, binding energy and molecular interactions. Our results show that mutation has caused significant increase in the binding energy between the spike and hACE2 in Alpha and Kappa variants. In the case of Kappa and Delta variants, the mutations at L452R, T478K and E484Q increased the stability and intra-chain interactions in the spike protein, which may change the interaction ability of neutralizing antibodies to these spike variants. Further, we found that the Alpha variant had increased hydrogen interaction with Lys353 of hACE2 and more binding affinity in comparison to WT. The current study provides the biophysical basis for understanding the molecular mechanism and rationale behind the increase in the transmissivity and infectivity of the mutants compared to wild-type SARS-CoV-2.


Assuntos
Enzima de Conversão de Angiotensina 2/metabolismo , COVID-19/transmissão , SARS-CoV-2/patogenicidade , Glicoproteína da Espícula de Coronavírus/metabolismo , Enzima de Conversão de Angiotensina 2/ultraestrutura , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/metabolismo , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/metabolismo , COVID-19/virologia , Cristalografia por Raios X , Humanos , Simulação de Dinâmica Molecular , Mutação , Estabilidade Proteica , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/ultraestrutura , Termodinâmica
16.
EBioMedicine ; 71: 103561, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34455390

RESUMO

BACKGROUND: Assessment of the kinetics of SARS-CoV-2 antibodies is essential in predicting risk of reinfection and durability of vaccine protection. METHODS: This is a prospective, monocentric, longitudinal, cohort clinical study. Healthcare workers (HCW) from Strasbourg University Hospital were enrolled between April 6th and May 7th, 2020 and followed up to 422 days. Serial serum samples were tested for antibodies against the Receptor Binding Domain (RBD) of the spike protein and nucleocapsid protein (N) to characterize the kinetics of SARS-CoV-2 antibodies and the incidence of reinfection. Live-neutralization assays were performed for a subset of samples before and after vaccination to analyze sensitivity to SARS-CoV-2 variants. FINDINGS: A total of 4290 samples from 393 convalescent COVID-19 and 916 COVID-19 negative individuals were analyzed. In convalescent individuals, SARS-CoV-2 antibodies followed a triphasic kinetic model with half-lives at month (M) 11-13 of 283 days (95% CI 231-349) for anti-N and 725 days (95% CI 623-921) for anti-RBD IgG, which stabilized at a median of 1.54 log BAU/mL (95% CI 1.42-1.67). The incidence of SARS-CoV-2 infections was 12.22 and 0.40 per 100 person-years in COVID-19-negative and COVID-19-positive HCW, respectively, indicating a relative reduction in the incidence of SARS-CoV-2 reinfection of 96.7%. Live-virus neutralization assay revealed that after one year, variants D614G and B.1.1.7, but less so B.1.351, were sensitive to anti-RBD antibodies at 1.4 log BAU/mL, while IgG ≥ 2.0 log BAU/mL strongly neutralized all three variants. These latter anti-RBD IgG titers were reached by all vaccinated HCW regardless of pre-vaccination IgG levels and type of vaccine. INTERPRETATION: Our study demonstrates a long-term persistence of anti-RBD antibodies that may reduce risk of reinfection. By significantly increasing cross-neutralizing antibody titers, a single-dose vaccination strengthens protection against variants. FUN1DING: None.


Assuntos
COVID-19/patologia , Imunidade Humoral , Reinfecção/patologia , Adulto , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/metabolismo , COVID-19/imunologia , COVID-19/virologia , Vacinas contra COVID-19/administração & dosagem , Vacinas contra COVID-19/imunologia , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina G/metabolismo , Cinética , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Fosfoproteínas/imunologia , Estudos Prospectivos , SARS-CoV-2/isolamento & purificação , SARS-CoV-2/metabolismo , Glicoproteína da Espícula de Coronavírus/imunologia , Fatores de Tempo
18.
Cells ; 10(8)2021 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-34440710

RESUMO

The aim of this study was to investigate the kinetics of neutralizing antibodies (NAbs) and anti-SARS-CoV-2 anti-S-RBD IgGs up to three months after the second vaccination dose with the BNT162b2 mRNA vaccine. NAbs and anti-S-RBD levels were measured on days 1 (before the first vaccine shot), 8, 22 (before the second shot), 36, 50, and three months after the second vaccination (D111) (NCT04743388). 283 health workers were included in this study. NAbs showed a rapid increase from D8 to D36 at a constant rate of about 3% per day and reached a median (SD) of 97.2% (4.7) at D36. From D36 to D50, a slight decrease in NAbs values was detected and it became more prominent between D50 and D111 when the rate of decline was determined at -0.11 per day. The median (SD) NAbs value at D111 was 92.7% (11.8). A similar pattern was also observed for anti-S-RBD antibodies. Anti-S-RBDs showed a steeper increase during D22-D36 and a lower decline rate during D36-D111. Prior COVID-19 infection and younger age were associated with superior antibody responses over time. In conclusion, we found a persistent but declining anti-SARS-CoV-2 humoral immunity at 3 months following full vaccination with BNT162b2 in healthy individuals.


Assuntos
Anticorpos Antivirais/imunologia , Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , SARS-CoV-2/imunologia , Adulto , Idoso , Anticorpos Antivirais/metabolismo , Formação de Anticorpos , Feminino , Humanos , Cinética , Masculino , Pessoa de Meia-Idade , Adulto Jovem
19.
Immunity ; 54(9): 2143-2158.e15, 2021 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-34453881

RESUMO

Neutralizing antibodies (NAbs) are effective in treating COVID-19, but the mechanism of immune protection is not fully understood. Here, we applied live bioluminescence imaging (BLI) to monitor the real-time effects of NAb treatment during prophylaxis and therapy of K18-hACE2 mice intranasally infected with SARS-CoV-2-nanoluciferase. Real-time imaging revealed that the virus spread sequentially from the nasal cavity to the lungs in mice and thereafter systemically to various organs including the brain, culminating in death. Highly potent NAbs from a COVID-19 convalescent subject prevented, and also effectively resolved, established infection when administered within three days. In addition to direct neutralization, depletion studies indicated that Fc effector interactions of NAbs with monocytes, neutrophils, and natural killer cells were required to effectively dampen inflammatory responses and limit immunopathology. Our study highlights that both Fab and Fc effector functions of NAbs are essential for optimal in vivo efficacy against SARS-CoV-2.


Assuntos
Anticorpos Neutralizantes/metabolismo , Anticorpos Antivirais/metabolismo , Encéfalo/patologia , COVID-19/imunologia , Pulmão/patologia , SARS-CoV-2/fisiologia , Testículo/patologia , Enzima de Conversão de Angiotensina 2/genética , Animais , Anticorpos Neutralizantes/genética , Anticorpos Antivirais/genética , Encéfalo/virologia , COVID-19/terapia , Células Cultivadas , Modelos Animais de Doenças , Humanos , Fragmentos Fc das Imunoglobulinas/genética , Luciferases/genética , Medições Luminescentes , Pulmão/virologia , Masculino , Camundongos , Camundongos Transgênicos , Testículo/virologia
20.
Immunity ; 54(9): 2159-2166.e6, 2021 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-34464596

RESUMO

The emergence of SARS-CoV-2 antigenic variants with increased transmissibility is a public health threat. Some variants show substantial resistance to neutralization by SARS-CoV-2 infection- or vaccination-induced antibodies. Here, we analyzed receptor binding domain-binding monoclonal antibodies derived from SARS-CoV-2 mRNA vaccine-elicited germinal center B cells for neutralizing activity against the WA1/2020 D614G SARS-CoV-2 strain and variants of concern. Of five monoclonal antibodies that potently neutralized the WA1/2020 D614G strain, all retained neutralizing capacity against the B.1.617.2 variant, four also neutralized the B.1.1.7 variant, and only one, 2C08, also neutralized the B.1.351 and B.1.1.28 variants. 2C08 reduced lung viral load and morbidity in hamsters challenged with the WA1/2020 D614G, B.1.351, or B.1.617.2 strains. Clonal analysis identified 2C08-like public clonotypes among B cells responding to SARS-CoV-2 infection or vaccination in 41 out of 181 individuals. Thus, 2C08-like antibodies can be induced by SARS-CoV-2 vaccines and mitigate resistance by circulating variants of concern.


Assuntos
Anticorpos Monoclonais/metabolismo , Anticorpos Neutralizantes/metabolismo , Anticorpos Antivirais/metabolismo , Linfócitos B/imunologia , Vacinas contra COVID-19/imunologia , COVID-19/imunologia , Centro Germinativo/imunologia , Pulmão/virologia , SARS-CoV-2/fisiologia , Animais , Células Cultivadas , Células Clonais , Cricetinae , Modelos Animais de Doenças , Humanos , Testes de Neutralização , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinação , Carga Viral
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