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1.
Vaccimonitor (La Habana, Print) ; 30(2)mayo.-ago. 2021. tab, graf
Artigo em Espanhol | LILACS, CUMED | ID: biblio-1252325

RESUMO

El uso de anticuerpos monoclonales en la lucha contra el cáncer se convierte cada día más en la terapia de elección. Para la introducción de anticuerpos monoclonales en mercados internacionales de alta demanda y con elevados requerimientos de calidad se requiere su producción a gran escala. El incremento de la presencia de dímeros en el producto final afecta su calidad y, por tanto, la eficiencia y eficacia del proceso. El objetivo del presente trabajo fue obtener un modelo matemático que permita relacionar el porcentaje de dímeros con las variables de operación de mayor influencia. Se realizó el ajuste de un modelo de regresión lineal múltiple usando el programa Statgraphics Centurion XVII versión 17.2.00. El modelo se validó con lotes de producción, logrando errores relativos inferiores al 20 por ciento. Las variables significativas obtenidas fueron: masa de IgG en el sobrenadante; masa de IgG en el producto de salida del paso de captura de proteína A; pH en el producto de salida del paso de captura de proteína A; pH del producto ajustado y conductividad de salida en la membrana de intercambio aniónico. El modelo permitió encontrar un intervalo de trabajo de las variables de mayor influencia en la formación de dímeros para reducirlos hasta valores inferiores al 3 por ciento(AU)


The use of monoclonal antibodies in the fight against cancer is becoming more and more the selected therapy. The introduction of monoclonal antibodies highly demanded in international markets, with high quality requirements needs the production of monoclonal antibodies on a large scale. The increase of dimers in the final product affects its quality, therefore, the efficiency and effectiveness of the process. The objective of this work was to obtain a mathematical model to relate the percentage of dimers with the most influential operating variables. A multiple linear regression model was obtained using Statgraphics Centurion XVII version 17.2.00 software. The model was validated with new production data with a mean error of validation below 20 percent. The significant variables were: supernatant IgG mass; IgG mass in the effluent from Protein A capture column; pH of the effluent from Protein A capture column; pH of the adjusted product and conductivity of the effluent from anionic exchange membrane. A working interval for each of the influential variables were established, in order to reduce dimers below 3 percent(AU)


Assuntos
Humanos , Computação Matemática , Análise de Dados , Anticorpos Monoclonais/imunologia , Neoplasias/mortalidade , Cuba
2.
Cell Rep ; 36(2): 109353, 2021 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-34237283

RESUMO

SARS-CoV-2 is one of three coronaviruses that have crossed the animal-to-human barrier and caused widespread disease in the past two decades. The development of a universal human coronavirus vaccine could prevent future pandemics. We characterize 198 antibodies isolated from four COVID-19+ subjects and identify 14 SARS-CoV-2 neutralizing antibodies. One targets the N-terminal domain (NTD), one recognizes an epitope in S2, and 11 bind the receptor-binding domain (RBD). Three anti-RBD neutralizing antibodies cross-neutralize SARS-CoV-1 by effectively blocking binding of both the SARS-CoV-1 and SARS-CoV-2 RBDs to the ACE2 receptor. Using the K18-hACE transgenic mouse model, we demonstrate that the neutralization potency and antibody epitope specificity regulates the in vivo protective potential of anti-SARS-CoV-2 antibodies. All four cross-neutralizing antibodies neutralize the B.1.351 mutant strain. Thus, our study reveals that epitopes in S2 can serve as blueprints for the design of immunogens capable of eliciting cross-neutralizing coronavirus antibodies.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , COVID-19/imunologia , COVID-19/prevenção & controle , Glicoproteína da Espícula de Coronavírus/imunologia , Enzima de Conversão de Angiotensina 2/química , Enzima de Conversão de Angiotensina 2/imunologia , Animais , Anticorpos Antivirais/química , Anticorpos Antivirais/imunologia , Sítios de Ligação , Linhagem Celular , Reações Cruzadas , Epitopos/imunologia , Feminino , Células HEK293 , Humanos , Camundongos , Testes de Neutralização , Ligação Proteica/imunologia , Domínios Proteicos , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/química
3.
Cell Rep ; 36(2): 109385, 2021 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-34237284

RESUMO

Administration of convalescent plasma or neutralizing monoclonal antibodies (mAbs) is a potent therapeutic option for coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, SARS-CoV-2 variants with mutations in the spike protein have emerged in many countries. To evaluate the efficacy of neutralizing antibodies induced in convalescent patients against emerging variants, we isolate anti-spike mAbs from two convalescent COVID-19 patients infected with prototypic SARS-CoV-2 by single-cell sorting of immunoglobulin-G-positive (IgG+) memory B cells. Anti-spike antibody induction is robust in these patients, and five mAbs have potent neutralizing activities. The efficacy of most neutralizing mAbs and convalescent plasma samples is maintained against B.1.1.7 and mink cluster 5 variants but is significantly decreased against variants B.1.351 from South Africa and P.1 from Brazil. However, mAbs with a high affinity for the receptor-binding domain remain effective against these neutralization-resistant variants. Rapid spread of these variants significantly impacts antibody-based therapies and vaccine strategies against SARS-CoV-2.


Assuntos
Anticorpos Neutralizantes/imunologia , COVID-19/imunologia , COVID-19/terapia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/isolamento & purificação , Anticorpos Antivirais/imunologia , COVID-19/virologia , Linhagem Celular , Células HEK293 , Humanos , Imunização Passiva , Masculino , Mutação , Testes de Neutralização , Domínios Proteicos , Glicoproteína da Espícula de Coronavírus/genética
4.
Int J Mol Sci ; 22(11)2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34200478

RESUMO

Candida auris is a multidrug-resistant fungal pathogen that can cause disseminated bloodstream infections with up to 60% mortality in susceptible populations. Of the three major classes of antifungal drugs, most C. auris isolates show high resistance to azoles and polyenes, with some clinical isolates showing resistance to all three drug classes. We reported in this study a novel approach to treating C. auris disseminated infections through passive transfer of monoclonal antibodies (mAbs) targeting cell surface antigens with high homology in medically important Candida species. Using an established A/J mouse model of disseminated infection that mimics human candidiasis, we showed that C3.1, a mAb that targets ß-1,2-mannotriose (ß-Man3), significantly extended survival and reduced fungal burdens in target organs, compared to control mice. We also demonstrated that two peptide-specific mAbs, 6H1 and 9F2, which target hyphal wall protein 1 (Hwp1) and phosphoglycerate kinase 1 (Pgk1), respectively, also provided significantly enhanced survival and reduction of fungal burdens. Finally, we showed that passive transfer of a 6H1+9F2 cocktail induced significantly enhanced protection, compared to treatment with either mAb individually. Our data demonstrate the utility of ß-Man3- and peptide-specific mAbs as an effective alternative to antifungals against medically important Candida species including multidrug-resistant C. auris.


Assuntos
Anticorpos Monoclonais/farmacologia , Antifúngicos/farmacologia , Candida/imunologia , Candidíase Invasiva/prevenção & controle , Proteínas de Membrana/imunologia , Animais , Anticorpos Monoclonais/imunologia , Candida/efeitos dos fármacos , Candidíase Invasiva/imunologia , Candidíase Invasiva/microbiologia , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL
5.
Viruses ; 13(6)2021 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-34207378

RESUMO

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is genetically variable, allowing it to adapt to various hosts including humans. Indeed, SARS-CoV-2 has accumulated around two mutations per genome each month. The first relevant event in this context was the occurrence of the mutant D614G in the Spike gene. Moreover, several variants have emerged, including the well-characterized 20I/501Y.V1, 20H/501Y.V2, and 20J/501Y.V3 strains, in addition to those that have been detected within clusters, such as 19B/501Y or 20C/655Y in France. Mutants have also emerged in animals, including a variant transmitted to humans, namely, the Mink variant detected in Denmark. The emergence of these variants has affected the transmissibility of the virus (for example, 20I/501Y.V1, which was up to 82% more transmissible than other preexisting variants), its severity, and its ability to escape natural, adaptive, vaccine, and therapeutic immunity. In this respect, we review the literature on variants that have currently emerged, and their effect on vaccines and therapies, and, in particular, monoclonal antibodies (mAbs). The emergence of SARS-CoV-2 variants must be examined to allow effective preventive and curative control strategies to be developed.


Assuntos
Anticorpos Monoclonais/imunologia , Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , COVID-19/terapia , Mutação , SARS-CoV-2/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/transmissão , Vacinas contra COVID-19/administração & dosagem , Humanos , SARS-CoV-2/genética
6.
Front Immunol ; 12: 678570, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34211469

RESUMO

Passive immunization using monoclonal antibodies will play a vital role in the fight against COVID-19. The recent emergence of viral variants with reduced sensitivity to some current antibodies and vaccines highlights the importance of broad cross-reactivity. This study describes deep-mining of the antibody repertoires of hospitalized COVID-19 patients using phage display technology and B cell receptor (BCR) repertoire sequencing to isolate neutralizing antibodies and gain insights into the early antibody response. This comprehensive discovery approach has yielded a panel of potent neutralizing antibodies which bind distinct viral epitopes including epitopes conserved in SARS-CoV-1. Structural determination of a non-ACE2 receptor blocking antibody reveals a previously undescribed binding epitope, which is unlikely to be affected by the mutations in any of the recently reported major viral variants including B.1.1.7 (from the UK), B.1.351 (from South Africa) and B.1.1.28 (from Brazil). Finally, by combining sequences of the RBD binding and neutralizing antibodies with the B cell receptor repertoire sequencing, we also describe a highly convergent early antibody response. Similar IgM-derived sequences occur within this study group and also within patient responses described by multiple independent studies published previously.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Anticorpos Neutralizantes/uso terapêutico , COVID-19/prevenção & controle , COVID-19/terapia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/imunologia , Técnicas de Visualização da Superfície Celular/métodos , Mineração de Dados/métodos , Epitopos/imunologia , Humanos , Imunização Passiva/métodos
7.
Front Immunol ; 12: 687869, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34220844

RESUMO

To determine whether the neutralization activity of monoclonal antibodies, convalescent sera and vaccine-elicited sera was affected by the top five epidemic SARS-CoV-2 variants in the UK, including D614G+L18F+A222V, D614G+A222V, D614G+S477N, VOC-202012/01(B.1.1.7) and D614G+69-70del+N439K, a pseudovirus-neutralization assay was performed to evaluate the relative neutralization titers against the five SARS-CoV-2 variants and 12 single deconvolution mutants based on the variants. In this study, 18 monoclonal antibodies, 10 sera from convalescent COVID-19 patients, 10 inactivated-virus vaccine-elicited sera, 14 mRNA vaccine-elicited sera, nine RBD-immunized mouse sera, four RBD-immunized horse sera, and four spike-encoding DNA-immunized guinea pig sera were tested and analyzed. The N501Y, N439K, and S477N mutations caused immune escape from nine of 18 mAbs. However, the convalescent sera, inactivated virus vaccine-elicited sera, mRNA vaccine-elicited sera, spike DNA-elicited sera, and recombinant RBD protein-elicited sera could still neutralize these variants (within three-fold changes compared to the reference D614G variant). The neutralizing antibody responses to different types of vaccines were different, whereby the response to inactivated-virus vaccine was similar to the convalescent sera.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/terapia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Animais , COVID-19/imunologia , Vacinas contra COVID-19/imunologia , Linhagem Celular , Células HEK293 , Humanos , Imunização Passiva , Camundongos , Testes de Neutralização/métodos , Reino Unido , Vacinação
8.
Int J Mol Sci ; 22(11)2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34206009

RESUMO

Toll-like receptor (TLR) signaling plays a critical role in the induction and progression of autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematous, experimental autoimmune encephalitis, type 1 diabetes mellitus and neurodegenerative diseases. Deciphering antigen recognition by antibodies provides insights and defines the mechanism of action into the progression of immune responses. Multiple strategies, including phage display and hybridoma technologies, have been used to enhance the affinity of antibodies for their respective epitopes. Here, we investigate the TLR4 antibody-binding epitope by computational-driven approach. We demonstrate that three important residues, i.e., Y328, N329, and K349 of TLR4 antibody binding epitope identified upon in silico mutagenesis, affect not only the interaction and binding affinity of antibody but also influence the structural integrity of TLR4. Furthermore, we predict a novel epitope at the TLR4-MD2 interface which can be targeted and explored for therapeutic antibodies and small molecules. This technique provides an in-depth insight into antibody-antigen interactions at the resolution and will be beneficial for the development of new monoclonal antibodies. Computational techniques, if coupled with experimental methods, will shorten the duration of rational design and development of antibody therapeutics.


Assuntos
Anticorpos Monoclonais/imunologia , Artrite Reumatoide/imunologia , Encefalite/imunologia , Epitopos/genética , Doença de Hashimoto/imunologia , Doenças Neurodegenerativas/imunologia , Receptor 4 Toll-Like/genética , Sequência de Aminoácidos/genética , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Artrite Reumatoide/genética , Técnicas de Visualização da Superfície Celular , Encefalite/genética , Encefalite/patologia , Mapeamento de Epitopos/métodos , Epitopos/imunologia , Doença de Hashimoto/genética , Doença de Hashimoto/patologia , Humanos , Doenças Neurodegenerativas/tratamento farmacológico , Doenças Neurodegenerativas/patologia , Ligação Proteica/genética , Receptor 4 Toll-Like/antagonistas & inibidores , Receptor 4 Toll-Like/imunologia
9.
Front Immunol ; 12: 659071, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34234774

RESUMO

SARS-CoV-2 is a newly emerged betacoronavirus and the causative agent for the COVID-19 pandemic. Antibodies recognizing the viral spike protein are instrumental in natural and vaccine-induced immune responses to the pathogen and in clinical diagnostic and therapeutic applications. Unlike conventional immunoglobulins, the variable lymphocyte receptor antibodies of jawless vertebrates are structurally distinct, indicating that they may recognize different epitopes. Here we report the isolation of monoclonal variable lymphocyte receptor antibodies from immunized sea lamprey larvae that recognize the spike protein of SARS-CoV-2 but not of other coronaviruses. We further demonstrate that these monoclonal variable lymphocyte receptor antibodies can efficiently neutralize the virus and form the basis of a rapid, single step SARS-CoV-2 detection system. This study provides evidence for monoclonal variable lymphocyte receptor antibodies as unique biomedical research and potential clinical diagnostic reagents targeting SARS-CoV-2.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/imunologia , Proteínas de Peixes/imunologia , Petromyzon/imunologia , SARS-CoV-2/fisiologia , Animais , Anticorpos Monoclonais/genética , Anticorpos Neutralizantes/genética , Anticorpos Antivirais/genética , Evolução Biológica , Reações Cruzadas , Epitopos de Linfócito B/imunologia , Proteínas de Peixes/genética , Humanos
10.
Nat Commun ; 12(1): 4196, 2021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-34234131

RESUMO

Monoclonal antibodies targeting a variety of epitopes have been isolated from individuals previously infected with SARS-CoV-2, but the relative contributions of these different antibody classes to the polyclonal response remains unclear. Here we use a yeast-display system to map all mutations to the viral spike receptor-binding domain (RBD) that escape binding by representatives of three potently neutralizing classes of anti-RBD antibodies with high-resolution structures. We compare the antibody-escape maps to similar maps for convalescent polyclonal plasmas, including plasmas from individuals from whom some of the antibodies were isolated. While the binding of polyclonal plasma antibodies are affected by mutations across multiple RBD epitopes, the plasma-escape maps most resemble those of a single class of antibodies that target an epitope on the RBD that includes site E484. Therefore, although the human immune system can produce antibodies that target diverse RBD epitopes, in practice the polyclonal response to infection is skewed towards a single class of antibodies targeting an epitope that is already undergoing rapid evolution.


Assuntos
Anticorpos Antivirais/imunologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Sítios de Ligação , COVID-19/imunologia , Epitopos , Antígenos HLA/imunologia , Humanos , Evasão da Resposta Imune/genética , Modelos Moleculares , Mutação , Testes de Neutralização , Domínios Proteicos , SARS-CoV-2/química , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/química
11.
Nat Commun ; 12(1): 4320, 2021 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-34262046

RESUMO

The rational development of norovirus vaccine candidates requires a deep understanding of the antigenic diversity and mechanisms of neutralization of the virus. Here, we isolate and characterize a panel of broadly cross-reactive naturally occurring human monoclonal IgMs, IgAs and IgGs reactive with human norovirus (HuNoV) genogroup I or II (GI or GII). We note three binding patterns and identify monoclonal antibodies (mAbs) that neutralize at least one GI or GII HuNoV strain when using a histo-blood group antigen (HBGA) blocking assay. The HBGA blocking assay and a virus neutralization assay using human intestinal enteroids reveal that the GII-specific mAb NORO-320, mediates HBGA blocking and neutralization of multiple GII genotypes. The Fab form of NORO-320 neutralizes GII.4 infection more potently than the mAb, however, does not block HBGA binding. The crystal structure of NORO-320 Fab in complex with GII.4 P-domain shows that the antibody recognizes a highly conserved region in the P-domain distant from the HBGA binding site. Dynamic light scattering analysis of GII.4 virus-like particles with mAb NORO-320 shows severe aggregation, suggesting neutralization is by steric hindrance caused by multivalent cross-linking. Aggregation was not observed with the Fab form of NORO-320, suggesting that this clone also has additional inhibitory features.


Assuntos
Anticorpos Antivirais/imunologia , Anticorpos Amplamente Neutralizantes/imunologia , Reações Cruzadas , Norovirus/imunologia , Sequência de Aminoácidos , Anticorpos Monoclonais/química , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/metabolismo , Anticorpos Antivirais/química , Anticorpos Antivirais/metabolismo , Variação Antigênica , Sítios de Ligação , Antígenos de Grupos Sanguíneos/metabolismo , Anticorpos Amplamente Neutralizantes/química , Anticorpos Amplamente Neutralizantes/metabolismo , Infecções por Caliciviridae/imunologia , Infecções por Caliciviridae/virologia , Proteínas do Capsídeo/química , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/imunologia , Proteínas do Capsídeo/metabolismo , Cristalografia por Raios X , Mapeamento de Epitopos , Genótipo , Humanos , Fragmentos Fab das Imunoglobulinas/química , Fragmentos Fab das Imunoglobulinas/imunologia , Fragmentos Fab das Imunoglobulinas/metabolismo , Norovirus/genética , Ligação Proteica , Domínios Proteicos
12.
Viruses ; 13(7)2021 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-34201767

RESUMO

We summarize here in vitro evidences of efficacy for convalescent plasma, currently approved vaccines and monoclonal antibodies against SARS-CoV-2 variants of concern (VOC: B.1.1.7, B.1.351, P.1, and B.1.617.2), variants of interest (VOI: B.1.427/B.1.429, P.2, B.1.525, P.3, B.1.526, and B.1.671.1), and other strains (B.1.1.298 and B.1.258delta). While waiting from real world clinical efficacy, these data provide guidance for the treating physician.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/sangue , Plasma/imunologia , SARS-CoV-2/imunologia , Vacinas Virais/imunologia , Anticorpos Monoclonais Humanizados/imunologia , Anticorpos Neutralizantes/imunologia , COVID-19/terapia , Humanos , Imunização Passiva/normas , Técnicas In Vitro , Testes de Neutralização , Glicoproteína da Espícula de Coronavírus/imunologia
13.
Cell Rep ; 36(2): 109364, 2021 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-34214467

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) variants govern transmissibility, responsiveness to vaccination, and disease severity. In a screen for new models of SARS-CoV-2 infection, we identify human H522 lung adenocarcinoma cells as naturally permissive to SARS-CoV-2 infection despite complete absence of angiotensin-converting enzyme 2 (ACE2) expression. Remarkably, H522 infection requires the E484D S variant; viruses expressing wild-type S are not infectious. Anti-S monoclonal antibodies differentially neutralize SARS-CoV-2 E484D S in H522 cells as compared to ACE2-expressing cells. Sera from vaccinated individuals block this alternative entry mechanism, whereas convalescent sera are less effective. Although the H522 receptor remains unknown, depletion of surface heparan sulfates block H522 infection. Temporally resolved transcriptomic and proteomic profiling reveal alterations in cell cycle and the antiviral host cell response, including MDA5-dependent activation of type I interferon signaling. These findings establish an alternative SARS-CoV-2 host cell receptor for the E484D SARS-CoV-2 variant, which may impact tropism of SARS-CoV-2 and consequently human disease pathogenesis.


Assuntos
COVID-19/imunologia , COVID-19/metabolismo , Receptores Virais , Glicoproteína da Espícula de Coronavírus/metabolismo , Substituição de Aminoácidos , Enzima de Conversão de Angiotensina 2 , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/imunologia , Ciclo Celular , Linhagem Celular Tumoral , Chlorocebus aethiops , Perfilação da Expressão Gênica , Heparitina Sulfato/metabolismo , Humanos , Interferon Tipo I/metabolismo , Helicase IFIH1 Induzida por Interferon/metabolismo , Modelos Biológicos , Ligação Proteica , Domínios Proteicos , Proteômica , Receptores Virais/metabolismo , SARS-CoV-2 , Serina Endopeptidases/metabolismo , Transdução de Sinais , Glicoproteína da Espícula de Coronavírus/genética , Células Vero , Internalização do Vírus , Replicação Viral
14.
ACS Appl Mater Interfaces ; 13(23): 26782-26789, 2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34077176

RESUMO

Technologies for rapid screening of multiple foodborne pathogens have been urgently needed because of the complex food matrix and high outbreaks of foodborne diseases. In this study, multicolor coding up-conversion nanoparticles (UCNPs) were synthesized and applied for rapid and simultaneous detection of five kinds of foodborne pathogens. The multicolor coding UCNPs were obtained through doping different concentrations of a sensitizer (Yb3+) on the shell of the synthesized NaYF4:Yb3+, Tm3+ (20%/2%)@NaYF4:Yb3+, and Er3+ (x %/2%) core/shell nanocrystals. All the UCNPs could emit red and green luminescence simultaneously once excited with near-infrared wavelength (980 nm), and the ratio of red and green (R/G ratio) emission light intensity of each kind of UCNPs varied depending on the Yb3+ doping concentration. In addition, the magnetic nanoparticles (MNPs) modified with the monoclonal antibodies (mAbs) against the target bacteria were used to capture and separate the bacteria, resulting in obtaining the MNP-bacterium complexes. Different UCNPs with multicolor coding acted as signal probes were also modified with the mAbs to react with the MNP-bacterium complexes to form the MNP-bacterium-UCNP sandwich complexes. After the sandwich complexes were excited with a wavelength of 980 nm, the obtained R/G ratios and the green photoluminescence intensity (PL intensity) could be used to distinguish and quantitatively detect foodborne pathogens, respectively. This proposed nanoplatform could detect five foodborne pathogens simultaneously within 2 h with good sensitivity and specificity, showing great potential for multiplex detection of other targets in the fields of medical diagnosis and food security.


Assuntos
Anticorpos Monoclonais/imunologia , Bactérias/patogenicidade , Doenças Transmitidas por Alimentos/diagnóstico , Luminescência , Nanopartículas de Magnetita/química , Bactérias/classificação , Bactérias/imunologia , Doenças Transmitidas por Alimentos/microbiologia , Medições Luminescentes
15.
Nat Commun ; 12(1): 3661, 2021 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-34135340

RESUMO

SARS-CoV-2, the virus responsible for COVID-19, has caused a global pandemic. Antibodies can be powerful biotherapeutics to fight viral infections. Here, we use the human apoferritin protomer as a modular subunit to drive oligomerization of antibody fragments and transform antibodies targeting SARS-CoV-2 into exceptionally potent neutralizers. Using this platform, half-maximal inhibitory concentration (IC50) values as low as 9 × 10-14 M are achieved as a result of up to 10,000-fold potency enhancements compared to corresponding IgGs. Combination of three different antibody specificities and the fragment crystallizable (Fc) domain on a single multivalent molecule conferred the ability to overcome viral sequence variability together with outstanding potency and IgG-like bioavailability. The MULTi-specific, multi-Affinity antiBODY (Multabody or MB) platform thus uniquely leverages binding avidity together with multi-specificity to deliver ultrapotent and broad neutralizers against SARS-CoV-2. The modularity of the platform also makes it relevant for rapid evaluation against other infectious diseases of global health importance. Neutralizing antibodies are a promising therapeutic for SARS-CoV-2.


Assuntos
Anticorpos Monoclonais/farmacologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/química , SARS-CoV-2/imunologia , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/química , Anticorpos Antivirais/imunologia , Especificidade de Anticorpos , Apoferritinas/química , Disponibilidade Biológica , Mapeamento de Epitopos , Humanos , Imunoglobulina G/imunologia , Masculino , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Engenharia de Proteínas/métodos , Subunidades Proteicas/química , Glicoproteína da Espícula de Coronavírus/imunologia , Distribuição Tecidual
16.
Cell ; 184(13): 3452-3466.e18, 2021 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-34139176

RESUMO

Antibodies against the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein prevent SARS-CoV-2 infection. However, the effects of antibodies against other spike protein domains are largely unknown. Here, we screened a series of anti-spike monoclonal antibodies from coronavirus disease 2019 (COVID-19) patients and found that some of antibodies against the N-terminal domain (NTD) induced the open conformation of RBD and thus enhanced the binding capacity of the spike protein to ACE2 and infectivity of SARS-CoV-2. Mutational analysis revealed that all of the infectivity-enhancing antibodies recognized a specific site on the NTD. Structural analysis demonstrated that all infectivity-enhancing antibodies bound to NTD in a similar manner. The antibodies against this infectivity-enhancing site were detected at high levels in severe patients. Moreover, we identified antibodies against the infectivity-enhancing site in uninfected donors, albeit at a lower frequency. These findings demonstrate that not only neutralizing antibodies but also enhancing antibodies are produced during SARS-CoV-2 infection.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Animais , COVID-19/imunologia , Linhagem Celular , Chlorocebus aethiops , Células HEK293 , Humanos , Ligação Proteica/imunologia , Domínios Proteicos/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Células Vero
17.
Cell ; 184(13): 3438-3451.e10, 2021 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-34139177

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been spreading worldwide, causing a global pandemic. Bat-origin RaTG13 is currently the most phylogenetically related virus. Here we obtained the complex structure of the RaTG13 receptor binding domain (RBD) with human ACE2 (hACE2) and evaluated binding of RaTG13 RBD to 24 additional ACE2 orthologs. By substituting residues in the RaTG13 RBD with their counterparts in the SARS-CoV-2 RBD, we found that residue 501, the major position found in variants of concern (VOCs) 501Y.V1/V2/V3, plays a key role in determining the potential host range of RaTG13. We also found that SARS-CoV-2 could induce strong cross-reactive antibodies to RaTG13 and identified a SARS-CoV-2 monoclonal antibody (mAb), CB6, that could cross-neutralize RaTG13 pseudovirus. These results elucidate the receptor binding and host adaption mechanisms of RaTG13 and emphasize the importance of continuous surveillance of coronaviruses (CoVs) carried by animal reservoirs to prevent another spillover of CoVs.


Assuntos
Enzima de Conversão de Angiotensina 2/metabolismo , Sítios de Ligação/fisiologia , COVID-19/metabolismo , Quirópteros/virologia , SARS-CoV-2/patogenicidade , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/imunologia , COVID-19/imunologia , Quirópteros/imunologia , Quirópteros/metabolismo , Especificidade de Hospedeiro/imunologia , Humanos , Filogenia , Ligação Proteica/fisiologia , Receptores Virais/metabolismo , SARS-CoV-2/imunologia , Alinhamento de Sequência
18.
Nature ; 595(7867): 426-431, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34126625

RESUMO

More than one year after its inception, the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains difficult to control despite the availability of several working vaccines. Progress in controlling the pandemic is slowed by the emergence of variants that appear to be more transmissible and more resistant to antibodies1,2. Here we report on a cohort of 63 individuals who have recovered from COVID-19 assessed at 1.3, 6.2 and 12 months after SARS-CoV-2 infection, 41% of whom also received mRNA vaccines3,4. In the absence of vaccination, antibody reactivity to the receptor binding domain (RBD) of SARS-CoV-2, neutralizing activity and the number of RBD-specific memory B cells remain relatively stable between 6 and 12 months after infection. Vaccination increases all components of the humoral response and, as expected, results in serum neutralizing activities against variants of concern similar to or greater than the neutralizing activity against the original Wuhan Hu-1 strain achieved by vaccination of naive individuals2,5-8. The mechanism underlying these broad-based responses involves ongoing antibody somatic mutation, memory B cell clonal turnover and development of monoclonal antibodies that are exceptionally resistant to SARS-CoV-2 RBD mutations, including those found in the variants of concern4,9. In addition, B cell clones expressing broad and potent antibodies are selectively retained in the repertoire over time and expand markedly after vaccination. The data suggest that immunity in convalescent individuals will be very long lasting and that convalescent individuals who receive available mRNA vaccines will produce antibodies and memory B cells that should be protective against circulating SARS-CoV-2 variants.


Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , COVID-19/sangue , COVID-19/imunologia , SARS-CoV-2/imunologia , Adulto , Idoso , Anticorpos Monoclonais/imunologia , Linfócitos B/imunologia , Ensaio de Imunoadsorção Enzimática , Epitopos/imunologia , Feminino , Humanos , Memória Imunológica/imunologia , Masculino , Pessoa de Meia-Idade , SARS-CoV-2/química , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/imunologia , Fatores de Tempo
19.
Toxins (Basel) ; 13(6)2021 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-34071768

RESUMO

This study aimed to detect and monitor total Zearalenone (ZEN) and its five homologs (ZENs) in cereals and feed. The monoclonal antibodies (mAbs) with a high affinity and broad class specificity against ZENs were prepared, and the conditions of a heterologous indirect competitive ELISA (icELISA) were preliminarily optimized based on the ZEN mAbs. The immunogen ZEN-BSA was synthesized using the oxime active ester method (OAE) and identified using infrared (IR) and ultraviolet (UV). The coating antigen ZEN-OVA was obtained via the 1,4-butanediol diglycidyl ether method (BDE). Balb/c mice were immunized using a high ZEN-BSA dose with long intervals and at multiple sites. A heterologous indirect non-competitive ELISA (inELISA) and an icELISA were used to screen the suitable cell fusion mice and positive hybridoma cell lines. The ZEN mAbs were prepared by inducing ascites in vivo. The standard curve was established, and the sensitivity and specificity of the ZEN mAbs were determined under the optimized icELISA conditions. ZEN-BSA was successfully synthesized at a conjugation ratio of 17.2:1 (ZEN: BSA). Three hybridoma cell lines, 2D7, 3C2, and 4A10, were filtered, and their mAbs corresponded to an IgG1 isotype with a κ light chain. The mAbs titers were between (2.56 to 5.12) × 102 in supernatants and (1.28 to 5.12) × 105 in the ascites. Besides, the 50% inhibitive concentration (IC50) values were from 18.65 to 31.92 µg/L in the supernatants and 18.12 to 31.46 µg/L in the ascites. The affinity constant (Ka) of all of the mAbs was between 4.15 × 109 and 6.54 × 109 L/mol. The IC50 values of mAb 2D7 for ZEN, α-ZEL, ß-ZEL, α-ZAL, ß-ZAL and ZAN were 17.23, 16.71, 18.27, 16.39, 20.36 and 15.01 µg/L, and their cross-reactivities (CRs, %) were 100%, 103.11%, 94.31%, 105.13%, 84.63%, and 114.79%, respectively, under the optimized icELISA conditions. The limit of detection (LOD) for ZEN was 0.64 µg/L, and its linear working range was between 1.03 and 288.55 µg/L. The mAbs preparation and the optimization of icELISA conditions promote the potential development of a rapid test ELISA kit, providing an alternative method for detecting ZEN and its homologs in cereals and feed.


Assuntos
Anticorpos Monoclonais/biossíntese , Afinidade de Anticorpos , Especificidade de Anticorpos , Zearalenona/imunologia , Animais , Anticorpos Monoclonais/imunologia , Linhagem Celular , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Soroalbumina Bovina/imunologia , Zearalenona/análise , Zearalenona/metabolismo
20.
Viruses ; 13(6)2021 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-34072720

RESUMO

Identification of therapeutics against emerging and re-emerging viruses remains a continued priority that is only reinforced by the recent SARS-CoV-2 pandemic. Advances in monoclonal antibody (mAb) isolation, characterization, and production make it a viable option for rapid treatment development. While mAbs are traditionally screened and selected based on potency of neutralization in vitro, it is clear that additional factors contribute to the in vivo efficacy of a mAb beyond viral neutralization. These factors include interactions with Fc receptors (FcRs) and complement that can enhance neutralization, clearance of infected cells, opsonization of virions, and modulation of the innate and adaptive immune response. In this review, we discuss recent studies, primarily using mouse models, that identified a role for Fc-FcγR interactions for optimal antibody-based protection against emerging and re-emerging virus infections.


Assuntos
Doenças Transmissíveis Emergentes/imunologia , Fragmentos Fc das Imunoglobulinas/imunologia , Receptores de IgG/imunologia , Viroses/imunologia , Vírus/imunologia , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/uso terapêutico , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/uso terapêutico , Citotoxicidade Celular Dependente de Anticorpos , Doenças Transmissíveis Emergentes/terapia , Doenças Transmissíveis Emergentes/virologia , Humanos , Imunização Passiva , Fagocitose , Viroses/terapia , Viroses/virologia , Vírus/classificação
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