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1.
Sci Rep ; 10(1): 16219, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33004978

RESUMO

COVID-19 pandemic has resulted in 16,114,449 cases with 646,641 deaths from the 217 countries, or territories as on July 27th 2020. Due to multifaceted issues and challenges in the implementation of the safety and preventive measures, inconsistent coordination between societies-governments and most importantly lack of specific vaccine to SARS-CoV-2, the spread of the virus that initially emerged at Wuhan is still uprising after taking a heavy toll on human life. In the present study, we mapped immunogenic epitopes present on the four structural proteins of SARS-CoV-2 and we designed a multi-epitope peptide based vaccine that, demonstrated a high immunogenic response with a vast application on world's human population. On codon optimization and in-silico cloning, we found that candidate vaccine showed high expression in E. coli and immune simulation resulted in inducing a high level of both B-cell and T-cell mediated immunity. The results predicted that exposure of vaccine by administrating three injections significantly subsidized the antigen growth in the system. The proposed candidate vaccine found promising by yielding desired results and hence, should be validated by practical experimentations for its functioning and efficacy to neutralize SARS-CoV-2.


Assuntos
Epitopos/imunologia , Simulação de Acoplamento Molecular , Vacinas de Subunidades/imunologia , Vacinas Virais/imunologia , Complexo Antígeno-Anticorpo/química , Complexo Antígeno-Anticorpo/imunologia , Antígenos Virais/imunologia , Linfócitos B/imunologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Epitopos/química , Antígenos HLA/química , Antígenos HLA/imunologia , Humanos , Imunogenicidade da Vacina , Proteínas do Nucleocapsídeo/química , Proteínas do Nucleocapsídeo/imunologia , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/imunologia , Linfócitos T/imunologia , Receptores Toll-Like/imunologia , Vacinas de Subunidades/química , Proteínas da Matriz Viral/química , Proteínas da Matriz Viral/imunologia , Vacinas Virais/química
3.
Signal Transduct Target Ther ; 5(1): 212, 2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32963228

RESUMO

The outbreaks of severe acute respiratory syndrome (SARS) and Coronavirus Disease 2019 (COVID-19) caused by SARS-CoV and SARS-CoV-2, respectively, have posed severe threats to global public health and the economy. Treatment and prevention of these viral diseases call for the research and development of human neutralizing monoclonal antibodies (NMAbs). Scientists have screened neutralizing antibodies using the virus receptor-binding domain (RBD) as an antigen, indicating that RBD contains multiple conformational neutralizing epitopes, which are the main structural domains for inducing neutralizing antibodies and T-cell immune responses. This review summarizes the structure and function of RBD and RBD-specific NMAbs against SARS-CoV and SARS-CoV-2 currently under development.


Assuntos
Anticorpos Monoclonais/química , Anticorpos Neutralizantes/química , Anticorpos Antivirais/química , Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Síndrome Respiratória Aguda Grave/prevenção & controle , Glicoproteína da Espícula de Coronavírus/química , Anticorpos Monoclonais/biossíntese , Anticorpos Neutralizantes/biossíntese , Anticorpos Antivirais/biossíntese , Betacoronavirus/efeitos dos fármacos , Betacoronavirus/imunologia , Betacoronavirus/patogenicidade , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Reações Cruzadas , Epitopos/química , Epitopos/imunologia , Epitopos/metabolismo , Humanos , Modelos Moleculares , Peptidil Dipeptidase A/química , Peptidil Dipeptidase A/imunologia , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Ligação Proteica , Estrutura Secundária de Proteína , Receptores Virais/química , Receptores Virais/imunologia , Receptores Virais/metabolismo , Vírus da SARS/efeitos dos fármacos , Vírus da SARS/imunologia , Vírus da SARS/patogenicidade , Síndrome Respiratória Aguda Grave/imunologia , Síndrome Respiratória Aguda Grave/virologia , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Vírion/imunologia , Vírion/ultraestrutura
4.
PLoS Pathog ; 16(8): e1008753, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32866207

RESUMO

The induction of broad and potent immunity by vaccines is the key focus of research efforts aimed at protecting against HIV-1 infection. Soluble native-like HIV-1 envelope glycoproteins have shown promise as vaccine candidates as they can induce potent autologous neutralizing responses in rabbits and non-human primates. In this study, monoclonal antibodies were isolated and characterized from rhesus macaques immunized with the BG505 SOSIP.664 trimer to better understand vaccine-induced antibody responses. Our studies reveal a diverse landscape of antibodies recognizing immunodominant strain-specific epitopes and non-neutralizing neo-epitopes. Additionally, we isolated a subset of mAbs against an epitope cluster at the gp120-gp41 interface that recognize the highly conserved fusion peptide and the glycan at position 88 and have characteristics akin to several human-derived broadly neutralizing antibodies.


Assuntos
Vacinas contra a AIDS/imunologia , Mapeamento de Epitopos , Epitopos/imunologia , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/imunologia , Proteína gp41 do Envelope de HIV/imunologia , HIV-1/imunologia , Vacinas contra a AIDS/genética , Animais , Anticorpos Monoclonais Murinos/imunologia , Epitopos/genética , Anticorpos Anti-HIV/genética , Proteína gp41 do Envelope de HIV/genética , HIV-1/genética , Macaca mulatta , Multimerização Proteica/genética , Multimerização Proteica/imunologia
5.
Cell Mol Immunol ; 17(10): 1095-1097, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32895485
6.
Nat Commun ; 11(1): 4420, 2020 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-32887876

RESUMO

SARS-CoV-2 enters host cells through an interaction between the spike glycoprotein and the angiotensin converting enzyme 2 (ACE2) receptor. Directly preventing this interaction presents an attractive possibility for suppressing SARS-CoV-2 replication. Here, we report the isolation and characterization of an alpaca-derived single domain antibody fragment, Ty1, that specifically targets the receptor binding domain (RBD) of the SARS-CoV-2 spike, directly preventing ACE2 engagement. Ty1 binds the RBD with high affinity, occluding ACE2. A cryo-electron microscopy structure of the bound complex at 2.9 Å resolution reveals that Ty1 binds to an epitope on the RBD accessible in both the 'up' and 'down' conformations, sterically hindering RBD-ACE2 binding. While fusion to an Fc domain renders Ty1 extremely potent, Ty1 neutralizes SARS-CoV-2 spike pseudovirus as a 12.8 kDa nanobody, which can be expressed in high quantities in bacteria, presenting opportunities for manufacturing at scale. Ty1 is therefore an excellent candidate as an intervention against COVID-19.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/farmacologia , Betacoronavirus/efeitos dos fármacos , Camelídeos Americanos/imunologia , Infecções por Coronavirus/tratamento farmacológico , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/tratamento farmacológico , Anticorpos de Domínio Único/farmacologia , Glicoproteína da Espícula de Coronavírus/antagonistas & inibidores , Sequência de Aminoácidos , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/farmacologia , Anticorpos Antivirais/química , Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Betacoronavirus/metabolismo , Sítios de Ligação , Chlorocebus aethiops , Infecções por Coronavirus/virologia , Microscopia Crioeletrônica , Epitopos/imunologia , Epitopos/metabolismo , Células HEK293 , Humanos , Masculino , Modelos Moleculares , Pandemias , Peptidil Dipeptidase A/química , Pneumonia Viral/virologia , Ligação Proteica , Anticorpos de Domínio Único/imunologia , Anticorpos de Domínio Único/isolamento & purificação , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Células Vero
7.
PLoS One ; 15(9): e0238089, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32903266

RESUMO

A novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) is the source of a current pandemic (COVID-19) with devastating consequences in public health and economic stability. Using a peptide array to map the antibody response of plasma from healing patients (12) and heathy patients (6), we identified three immunodominant linear epitopes, two of which correspond to key proteolytic sites on the spike protein (S1/S2 and S2') known to be critical for cellular entry. We show biochemical evidence that plasma positive for the epitope adjacent to the S1/S2 cleavage site inhibits furin-mediated proteolysis of spike.


Assuntos
Infecções por Coronavirus/patologia , Epitopos/química , Pneumonia Viral/patologia , Sequência de Aminoácidos , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/virologia , Mapeamento de Epitopos , Epitopos/sangue , Epitopos/imunologia , Furina/metabolismo , Humanos , Pandemias , Ácidos Nucleicos Peptídicos/química , Peptídeos/química , Pneumonia Viral/virologia , Análise Serial de Proteínas , Estrutura Terciária de Proteína , Proteólise , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Alinhamento de Sequência , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/metabolismo
8.
Genome Med ; 12(1): 70, 2020 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-32791978

RESUMO

BACKGROUND: The ongoing COVID-19 pandemic has created an urgency to identify novel vaccine targets for protective immunity against SARS-CoV-2. Early reports identify protective roles for both humoral and cell-mediated immunity for SARS-CoV-2. METHODS: We leveraged our bioinformatics binding prediction tools for human leukocyte antigen (HLA)-I and HLA-II alleles that were developed using mass spectrometry-based profiling of individual HLA-I and HLA-II alleles to predict peptide binding to diverse allele sets. We applied these binding predictors to viral genomes from the Coronaviridae family and specifically focused on T cell epitopes from SARS-CoV-2 proteins. We assayed a subset of these epitopes in a T cell induction assay for their ability to elicit CD8+ T cell responses. RESULTS: We first validated HLA-I and HLA-II predictions on Coronaviridae family epitopes deposited in the Virus Pathogen Database and Analysis Resource (ViPR) database. We then utilized our HLA-I and HLA-II predictors to identify 11,897 HLA-I and 8046 HLA-II candidate peptides which were highly ranked for binding across 13 open reading frames (ORFs) of SARS-CoV-2. These peptides are predicted to provide over 99% allele coverage for the US, European, and Asian populations. From our SARS-CoV-2-predicted peptide-HLA-I allele pairs, 374 pairs identically matched what was previously reported in the ViPR database, originating from other coronaviruses with identical sequences. Of these pairs, 333 (89%) had a positive HLA binding assay result, reinforcing the validity of our predictions. We then demonstrated that a subset of these highly predicted epitopes were immunogenic based on their recognition by specific CD8+ T cells in healthy human donor peripheral blood mononuclear cells (PBMCs). Finally, we characterized the expression of SARS-CoV-2 proteins in virally infected cells to prioritize those which could be potential targets for T cell immunity. CONCLUSIONS: Using our bioinformatics platform, we identify multiple putative epitopes that are potential targets for CD4+ and CD8+ T cells, whose HLA binding properties cover nearly the entire population. We also confirm that our binding predictors can predict epitopes eliciting CD8+ T cell responses from multiple SARS-CoV-2 proteins. Protein expression and population HLA allele coverage, combined with the ability to identify T cell epitopes, should be considered in SARS-CoV-2 vaccine design strategies and immune monitoring.


Assuntos
Infecções por Coronavirus/imunologia , Epitopos/imunologia , Antígenos HLA/imunologia , Pneumonia Viral/imunologia , Linfócitos T/imunologia , Vacinas Virais/imunologia , Alelos , Afinidade de Anticorpos , Biologia Computacional , Infecções por Coronavirus/genética , Infecções por Coronavirus/prevenção & controle , Epitopos/química , Epitopos/genética , Genoma Viral , Antígenos HLA/química , Antígenos HLA/genética , Humanos , Imunogenicidade da Vacina , Espectrometria de Massas , Pandemias , Vacinas Virais/química , Vacinas Virais/genética
9.
PLoS Pathog ; 16(8): e1008665, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32780770

RESUMO

Two-component, self-assembling nanoparticles represent a versatile platform for multivalent presentation of viral antigens. Computational design of protein nanoparticles with differing sizes and geometries enables combination with antigens of choice to test novel multimerization concepts in immunization strategies where the goal is to improve the induction and maturation of neutralizing antibody lineages. Here, we describe detailed antigenic, structural, and functional characterization of computationally designed tetrahedral, octahedral, and icosahedral nanoparticle immunogens displaying trimeric HIV envelope glycoprotein (Env) ectodomains. Env trimers, based on subtype A (BG505) or consensus group M (ConM) sequences and engineered with SOSIP stabilizing mutations, were fused to an underlying trimeric building block of each nanoparticle. Initial screening yielded one icosahedral and two tetrahedral nanoparticle candidates, capable of presenting twenty or four copies of the Env trimer. A number of analyses, including detailed structural characterization by cryo-EM, demonstrated that the nanoparticle immunogens possessed the intended structural and antigenic properties. When the immunogenicity of ConM-SOSIP trimers presented on a two-component tetrahedral nanoparticle or as soluble proteins were compared in rabbits, the two immunogens elicited similar serum antibody binding titers against the trimer component. Neutralizing antibody titers were slightly elevated in the animals given the nanoparticle immunogen and were initially more focused to the trimer apex. Altogether, our findings indicate that tetrahedral nanoparticles can be successfully applied for presentation of HIV Env trimer immunogens; however, the optimal implementation to different immunization strategies remains to be determined.


Assuntos
Anticorpos Anti-HIV/imunologia , Antígenos HIV/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Nanopartículas/química , Produtos do Gene env do Vírus da Imunodeficiência Humana/química , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Animais , Epitopos/imunologia , Feminino , Infecções por HIV/virologia , Humanos , Imunização , Nanopartículas/administração & dosagem , Coelhos , Produtos do Gene env do Vírus da Imunodeficiência Humana/genética
10.
Med Hypotheses ; 143: 110151, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32763661

RESUMO

Today it remains unclear why children seem to be less likely to get infected by COVID-19 or why they appear to be less symptomatic after infections. All individuals, especially children, are exposed to various viruses including human coronavirus (CoVs) that can generally lead to respiratory infections. We hypothesize that recurrent CoVs exposure may induce an effective antiviral B and T-cell-mediated adaptive immune response, which could also be protective against COVID-19. Based on the high-homology between the Spike protein epitopes of taxonomically-related coronaviruses, we theorize that past/recurrent contact with CoVs might shield children also against the circulating COVID-19 through a possible neutralizing antibody response previously CoVs-induced. This would open up possible lines of research for the development of live-attenuated virus vaccines from CoVs. Future research is desirable to confirm or disprove such hypothesis.


Assuntos
Betacoronavirus , Infecções por Coronavirus/epidemiologia , Memória Imunológica , Modelos Imunológicos , Pandemias , Pneumonia Viral/epidemiologia , Adulto , Distribuição por Idade , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Antígenos Virais/genética , Antígenos Virais/imunologia , Betacoronavirus/genética , Betacoronavirus/imunologia , Linfócitos T CD4-Positivos/imunologia , Criança , Coronavirus/genética , Coronavirus/imunologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/virologia , Reações Cruzadas , Resistência à Doença , Epitopos/genética , Epitopos/imunologia , Humanos , Peptidil Dipeptidase A/análise , Pneumonia Viral/imunologia , Alvéolos Pulmonares/química , Receptores Virais/análise , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/imunologia , Infecções Respiratórias/virologia , Homologia de Sequência de Aminoácidos , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinas Atenuadas , Vacinas Virais
11.
Science ; 369(6506): 936-942, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32820119

RESUMO

Intestinal microbiota have been proposed to induce commensal-specific memory T cells that cross-react with tumor-associated antigens. We identified major histocompatibility complex (MHC) class I-binding epitopes in the tail length tape measure protein (TMP) of a prophage found in the genome of the bacteriophage Enterococcus hirae Mice bearing E. hirae harboring this prophage mounted a TMP-specific H-2Kb-restricted CD8+ T lymphocyte response upon immunotherapy with cyclophosphamide or anti-PD-1 antibodies. Administration of bacterial strains engineered to express the TMP epitope improved immunotherapy in mice. In renal and lung cancer patients, the presence of the enterococcal prophage in stools and expression of a TMP-cross-reactive antigen by tumors correlated with long-term benefit of PD-1 blockade therapy. In melanoma patients, T cell clones recognizing naturally processed cancer antigens that are cross-reactive with microbial peptides were detected.


Assuntos
Antígenos de Neoplasias/imunologia , Bacteriófagos/imunologia , Streptococcus faecium ATCC 9790/virologia , Microbioma Gastrointestinal/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Imunoterapia/métodos , Neoplasias/terapia , Proteínas da Cauda Viral/imunologia , Animais , Anticorpos Monoclonais/uso terapêutico , Antineoplásicos Alquilantes/uso terapêutico , Linfócitos T CD8-Positivos/imunologia , Reações Cruzadas , Ciclofosfamida/uso terapêutico , Epitopos/imunologia , Fezes/virologia , Antígenos H-2/imunologia , Humanos , Camundongos , Neoplasias/dietoterapia , Neoplasias/imunologia , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/imunologia , Proteínas da Cauda Viral/uso terapêutico
12.
Arch Virol ; 165(10): 2301-2309, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32757056

RESUMO

Porcine circovirus type 2 (PCV2) is a major pathogen associated with swine diseases. It is the smallest single-stranded DNA virus, and its genome contains four major open reading frames (ORFs). ORF2 encodes the major structural protein Cap, which can self-assemble into virus-like particles (VLPs) in vitro and contains the primary antigenic determinants. In this study, we developed a high-efficiency method for obtaining VLPs and optimized the purification conditions. In this method, we expressed the protein Cap with a 6× His tag using baculovirus-infected silkworm larvae as well as the E. coli BL21(DE3) prokaryotic expression system. The PCV2 Cap proteins produced by the silkworm larvae and E. coli BL21(DE3) were purified. Cap proteins purified from silkworm larvae self-assembled into VLPs in vitro, while the Cap proteins purified from bacteria were unable to self-assemble. Transmission electron microscopy confirmed the self-assembly of VLPs. The immunogenicity of the VLPs produced using the baculovirus system was demonstrated using an enzyme-linked immunosorbent assay (ELISA). Furthermore, the purification process was optimized. The results demonstrated that the expression system using baculovirus-infected silkworm larvae is a good choice for obtaining VLPs of PCV2 and has potential for the development of a low-cost and efficient vaccine.


Assuntos
Anticorpos Antivirais/biossíntese , Baculoviridae/genética , Bombyx/virologia , Proteínas do Capsídeo/imunologia , Circovirus/imunologia , Vacinas de Partículas Semelhantes a Vírus/biossíntese , Vacinas Virais/biossíntese , Animais , Antígenos Virais/química , Antígenos Virais/imunologia , Baculoviridae/imunologia , Proteínas do Capsídeo/biossíntese , Proteínas do Capsídeo/genética , Infecções por Circoviridae/imunologia , Infecções por Circoviridae/prevenção & controle , Infecções por Circoviridae/virologia , Circovirus/genética , Epitopos/química , Epitopos/imunologia , Escherichia coli/genética , Escherichia coli/metabolismo , Feminino , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Histidina/genética , Histidina/imunologia , Soros Imunes/química , Imunogenicidade da Vacina , Larva/virologia , Camundongos , Oligopeptídeos/genética , Oligopeptídeos/imunologia , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/prevenção & controle , Doenças dos Suínos/virologia , Vacinas de Partículas Semelhantes a Vírus/administração & dosagem , Vacinas de Partículas Semelhantes a Vírus/genética , Vacinas de Partículas Semelhantes a Vírus/isolamento & purificação , Vacinas Virais/administração & dosagem , Vacinas Virais/genética , Vacinas Virais/isolamento & purificação
13.
PLoS Pathog ; 16(8): e1008736, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32745149

RESUMO

Human cytomegalovirus (HCMV) is one of the main causative agents of congenital viral infection in neonates. HCMV infection also causes serious morbidity and mortality among organ transplant patients. Glycoprotein B (gB) is a major target for HCMV neutralizing antibodies, yet the underlying neutralization mechanisms remain largely unknown. Here we report that 3-25, a gB-specific monoclonal antibody previously isolated from a healthy HCMV-positive donor, efficiently neutralized 14 HCMV strains in both ARPE-19 cells and MRC-5 cells. The core epitope of 3-25 was mapped to a highly conserved linear epitope on antigenic domain 2 (AD-2) of gB. A 1.8 Å crystal structure of 3-25 Fab in complex with the peptide epitope revealed the molecular determinants of 3-25 binding to gB at atomic resolution. Negative-staining electron microscopy (EM) 3D reconstruction of 3-25 Fab in complex with de-glycosylated postfusion gB showed that 3-25 Fab fully occupied the gB trimer at the N-terminus with flexible binding angles. Functionally, 3-25 efficiently inhibited HCMV infection at a post-attachment step by interfering with viral membrane fusion, and restricted post-infection viral spreading in ARPE-19 cells. Interestingly, bivalency was required for HCMV neutralization by AD-2 specific antibody 3-25 but not the AD-4 specific antibody LJP538. In contrast, bivalency was not required for HCMV binding by both antibodies. Taken together, our results reveal the structural basis of gB recognition by 3-25 and demonstrate that inhibition of viral membrane fusion and a requirement of bivalency may be common for gB AD-2 specific neutralizing antibody.


Assuntos
Anticorpos Antivirais/imunologia , Infecções por Citomegalovirus/imunologia , Citomegalovirus/imunologia , Epitopos/imunologia , Proteínas do Envelope Viral/imunologia , Motivos de Aminoácidos , Anticorpos Neutralizantes/imunologia , Sequência Conservada , Citomegalovirus/química , Citomegalovirus/genética , Citomegalovirus/fisiologia , Infecções por Citomegalovirus/virologia , Epitopos/química , Epitopos/genética , Humanos , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/genética , Internalização do Vírus
14.
Biophys Chem ; 265: 106441, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32745829

RESUMO

The possibility of immobilizing a protein with antigenic properties on a solid support offers significant possibilities in the development of immunosensors and vaccine formulations. For both applications, the orientation of the antigen should ensure ready accessibility of the antibodies to the epitope. However, an experimental assessment of the orientational preferences necessarily proceeds through the preparation/isolation of the antigen, the immobilization on different surfaces and one or more biophysical characterization steps. To predict a priori whether favorable orientations can be achieved or not would allow one to select the most promising experimental routes, partly mitigating the time cost towards the final product. In this manuscript, we apply a simple computational model, based on united-residue modelling, to the prediction of the orientation of the receptor binding domain of the SARS-CoV-2 spike protein on surfaces commonly used in lateral-flow devices. These calculations can account for the experimental observation that direct immobilization on gold gives sufficient exposure of the epitope to obtain a response in immunochemical assays.


Assuntos
Betacoronavirus/metabolismo , Epitopos/química , Modelos Moleculares , Glicoproteína da Espícula de Coronavírus/metabolismo , Antígenos/química , Antígenos/imunologia , Antígenos/metabolismo , Epitopos/imunologia , Simulação de Acoplamento Molecular , Domínios Proteicos , Dióxido de Silício/química , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/imunologia , Propriedades de Superfície
15.
Nat Commun ; 11(1): 3971, 2020 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-32769993

RESUMO

Efficacy evaluation through human trials is crucial for advancing a vaccine candidate to clinics. Next-generation sequencing (NGS) can be used to quantify B cell repertoire response and trace antibody lineages during vaccination. Here, we demonstrate this application with a case study of Hecolin®, the licensed vaccine for hepatitis E virus (HEV). Four subjects are administered the vaccine following a standard three-dose schedule. Vaccine-induced antibodies exhibit a high degree of clonal diversity, recognize five conformational antigenic sites of the genotype 1 HEV p239 antigen, and cross-react with other genotypes. Unbiased repertoire sequencing is performed for seven time points over six months of vaccination, with maturation pathways characterize for a set of vaccine-induced antibodies. In addition to dynamic repertoire profiles, NGS analysis reveals differential patterns of HEV-specific antibody lineages and highlights the necessity of the long vaccine boost. Together, our study presents a quantitative strategy for vaccine evaluation in small-scale human studies.


Assuntos
Anticorpos Antivirais/imunologia , Formação de Anticorpos/imunologia , Vírus da Hepatite E/imunologia , Vacinação , Vacinas contra Hepatite Viral/imunologia , Adulto , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Especificidade de Anticorpos/imunologia , Linfócitos B/imunologia , Epitopos/imunologia , Genótipo , Vírus da Hepatite E/genética , Humanos , Fatores de Tempo , Doadores de Tecidos , Adulto Jovem
16.
PLoS One ; 15(7): e0235815, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32673351

RESUMO

Monoclonal antibodies (mAbs) for therapeutic applications should be as similar to native human antibodies as possible to minimize their immunogenicity in patients. Several transgenic animal platforms are available for the generation of fully human mAbs. Attributes such as specificity, efficacy and Chemistry, Manufacturing and Controls (CMC) developability of antibodies against a specific target are typically established for antibodies obtained from one platform only. In this study, monoclonal antibodies (mAbs) cross-reactive against human and cynomolgus LAMP1 were derived from the human immunoglobulin transgenic TRIANNI mouse and OmniChicken® platforms and assessed for their specificity, sequence diversity, ability to bind to and internalize into tumor cells, expected immunogenicity and CMC developability. Our results show that the two platforms were complementary at providing a large diversity of mAbs with respect to epitope coverage and antibody sequence diversity. Furthermore, most antibodies originating from either platform exhibited good manufacturability characteristics.


Assuntos
Anticorpos Monoclonais/imunologia , Epitopos/imunologia , Glicoproteínas de Membrana Associadas ao Lisossomo/imunologia , Animais , Animais Geneticamente Modificados , Anticorpos Monoclonais/química , Galinhas , Células HEK293 , Humanos , Imunização , Macaca fascicularis , Camundongos , Modelos Moleculares
18.
Cell Rep ; 32(3): 107918, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32668215

RESUMO

Coronavirus disease 2019 (COVID-19) has become a worldwide threat to humans, and neutralizing antibodies have therapeutic potential. We have purified more than 1,000 memory B cells specific to SARS-CoV-2 S1 or its RBD (receptor binding domain) and obtain 729 paired heavy- and light-chain fragments. Among these, 178 antibodies test positive for antigen binding, and the majority of the top 17 binders with EC50 below 1 nM are RBD binders. Furthermore, we identify 11 neutralizing antibodies, eight of which show IC50 within 10 nM, and the best one, 414-1, with IC50 of 1.75 nM. Through epitope mapping, we find three main epitopes in RBD recognized by these antibodies, and epitope-B antibody 553-15 could substantially enhance the neutralizing abilities of most of the other antibodies. We also find that 515-5 could cross neutralize the SARS-CoV pseudovirus. Altogether, our study provides 11 potent human neutralizing antibodies for COVID-19 as therapeutic candidates.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Receptores Virais/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Anticorpos Monoclonais/uso terapêutico , Linfócitos B/imunologia , Infecções por Coronavirus/terapia , Mapeamento de Epitopos , Epitopos/imunologia , Humanos , Memória Imunológica/imunologia , Testes de Neutralização , Pandemias , Pneumonia Viral/terapia , Domínios Proteicos/imunologia
19.
F1000Res ; 9: 285, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32595955

RESUMO

SARS-CoV-2 is the coronavirus agent of the COVID-19 pandemic causing high mortalities. In contrast, the widely spread human coronaviruses OC43, HKU1, 229E, and NL63 tend to cause only mild symptoms. The present study shows, by in silico analysis, that these common human viruses are expected to induce immune memory against SARS-CoV-2 by sharing protein fragments (antigen epitopes) for presentation to the immune system by MHC class I. A list of such epitopes is provided. The number of these epitopes and the prevalence of the common coronaviruses suggest that a large part of the world population has some degree of specific immunity against SARS-CoV-2 already, even without having been infected by that virus. For inducing protection, booster vaccinations enhancing existing immunity are less demanding than primary vaccinations against new antigens. Therefore, for the discussion on vaccination strategies against COVID-19, the available immune memory against related viruses should be part of the consideration.


Assuntos
Antígenos Virais/imunologia , Infecções por Coronavirus/imunologia , Memória Imunológica , Pneumonia Viral/imunologia , Betacoronavirus , Coronavirus/classificação , Epitopos/imunologia , Humanos , Pandemias
20.
Nat Commun ; 11(1): 3418, 2020 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-32647286

RESUMO

The emergence and spread of antiviral drug-resistant viruses have been a worldwide challenge and a great concern for patient care. We report A4 antibody specifically recognizing and binding to the mutant I223R/H275Y neuraminidase and prove the applicability of A4 antibody for direct detection of antiviral multidrug-resistant viruses in various sensing platforms, including naked-eye detection, surface-enhanced Raman scattering-based immunoassay, and lateral flow system. The development of the A4 antibody enables fast, simple, and reliable point-of-care assays of antiviral multidrug-resistant influenza viruses. In addition to current influenza virus infection testing methods that do not provide information on the antiviral drug-resistance of the virus, diagnostic tests for antiviral multidrug-resistant viruses will improve clinical judgment in the treatment of influenza virus infections, avoid the unnecessary prescription of ineffective drugs, and improve current therapies.


Assuntos
Anticorpos Antivirais/imunologia , Resistência a Múltiplos Medicamentos/imunologia , Farmacorresistência Viral/imunologia , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H3N2/imunologia , Mutação/genética , Neuraminidase/genética , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/química , Afinidade de Anticorpos/imunologia , Antígenos Virais/metabolismo , Líquidos Corporais/virologia , Análise Mutacional de DNA , Cães , Epitopos/química , Epitopos/imunologia , Humanos , Vírus da Influenza A Subtipo H1N1/enzimologia , Vírus da Influenza A Subtipo H3N2/enzimologia , Células Madin Darby de Rim Canino , Simulação de Acoplamento Molecular , Imagem Óptica , Ligação Proteica , Análise Espectral Raman
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