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3.
mSphere ; 5(5)2020 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-32938700

RESUMO

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to spread around the world, there is an urgent need for new assay formats to characterize the humoral response to infection. Here, we present an efficient, competitive serological assay that can simultaneously determine an individual's seroreactivity against the SARS-CoV-2 Spike protein and determine the proportion of anti-Spike antibodies that block interaction with the human angiotensin-converting enzyme 2 (ACE2) required for viral entry. In this approach based on the use of enzyme-linked immunosorbent assays (ELISA), we present natively folded viral Spike protein receptor-binding domain (RBD)-containing antigens via avidin-biotin interactions. Sera are then competed with soluble ACE2-Fc, or with a higher-affinity variant thereof, to determine the proportion of ACE2 blocking anti-RBD antibodies. Assessment of sera from 144 SARS-CoV-2 patients ultimately revealed that a remarkably consistent and high proportion of antibodies in the anti-RBD pool targeted the epitope responsible for ACE2 engagement (83% ± 11%; 50% to 107% signal inhibition in our largest cohort), further underscoring the importance of tailoring vaccines to promote the development of such antibodies.IMPORTANCE With the emergence and continued spread of the SARS-CoV-2 virus, and of the associated disease, coronavirus disease 2019 (COVID-19), there is an urgent need for improved understanding of how the body mounts an immune response to the virus. Here, we developed a competitive SARS-CoV-2 serological assay that can simultaneously determine whether an individual has developed antibodies against the SARS-CoV-2 Spike protein receptor-binding domain (RBD) and measure the proportion of these antibodies that block interaction with the human angiotensin-converting enzyme 2 (ACE2) required for viral entry. Using this assay and 144 SARS-CoV-2 patient serum samples, we found that a majority of anti-RBD antibodies compete for ACE2 binding. These results not only highlight the need to design vaccines to generate such blocking antibodies but also demonstrate the utility of this assay to rapidly screen patient sera for potentially neutralizing antibodies.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Peptidil Dipeptidase A/imunologia , Testes Sorológicos/métodos , Glicoproteína da Espícula de Coronavírus/imunologia , Antígenos Virais/imunologia , Sítios de Ligação/imunologia , Infecções por Coronavirus/prevenção & controle , Ensaios de Triagem em Larga Escala/métodos , Humanos , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Ligação Proteica , Domínios Proteicos/imunologia
5.
Emerg Microbes Infect ; 9(1): 2076-2090, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32897177

RESUMO

The current coronavirus disease 2019 (COVID-19) pandemic was the result of the rapid transmission of a highly pathogenic coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), for which there is no efficacious vaccine or therapeutic. Toward the development of a vaccine, here we expressed and evaluated as potential candidates four versions of the spike (S) protein using an insect cell expression system: receptor binding domain (RBD), S1 subunit, the wild-type S ectodomain (S-WT), and the prefusion trimer-stabilized form (S-2P). We showed that RBD appears as a monomer in solution, whereas S1, S-WT, and S-2P associate as homotrimers with substantial glycosylation. Cryo-electron microscopy analyses suggested that S-2P assumes an identical trimer conformation as the similarly engineered S protein expressed in 293 mammalian cells but with reduced glycosylation. Overall, the four proteins confer excellent antigenicity with convalescent COVID-19 patient sera in enzyme-linked immunosorbent assay (ELISA), yet show distinct reactivities in immunoblotting. RBD, S-WT and S-2P, but not S1, induce high neutralization titres (>3-log) in mice after a three-round immunization regimen. The high immunogenicity of S-2P could be maintained at the lowest dose (1 µg) with the inclusion of an aluminium adjuvant. Higher doses (20 µg) of S-2P can elicit high neutralization titres in non-human primates that exceed 40-times the mean titres measured in convalescent COVID-19 subjects. Our results suggest that the prefusion trimer-stabilized SARS-CoV-2 S-protein from insect cells may offer a potential candidate strategy for the development of a recombinant COVID-19 vaccine.


Assuntos
Antígenos Virais/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Imunogenicidade da Vacina/imunologia , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Linhagem Celular , Infecções por Coronavirus/imunologia , Microscopia Crioeletrônica , Ensaio de Imunoadsorção Enzimática , Humanos , Macaca fascicularis , Camundongos , Camundongos Endogâmicos BALB C , Testes de Neutralização , Peptidil Dipeptidase A/metabolismo , Domínios Proteicos/genética , Domínios Proteicos/imunologia , Células Sf9 , Glicoproteína da Espícula de Coronavírus/genética , Spodoptera , Vacinação , Proteínas do Envelope Viral/imunologia
6.
Emerg Microbes Infect ; 9(1): 2091-2093, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32930052

RESUMO

We studied plasma antibody responses of 35 patients about 1 month after SARS-CoV-2 infection. Titers of antibodies binding to the viral nucleocapsid and spike proteins were significantly higher in patients with severe disease. Likewise, mean antibody neutralization titers against SARS-CoV-2 pseudovirus and live virus were higher in the sicker patients, by ∼5-fold and ∼7-fold, respectively. These findings have important implications for those pursuing plasma therapy, isolation of neutralizing monoclonal antibodies, and determinants of immunity.


Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Betacoronavirus/imunologia , Nucleocapsídeo/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Adulto , Idoso , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Antígenos Virais/imunologia , Infecções por Coronavirus/imunologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes de Neutralização , Pandemias , Pneumonia Viral/imunologia , Índice de Gravidade de Doença , Proteínas do Envelope Viral/imunologia
7.
Int J Mol Sci ; 21(18)2020 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-32933166

RESUMO

The glycans on enveloped viruses are synthesized by host-cell machinery. Some of these glycans on zoonotic viruses of mammalian reservoirs are recognized by human natural antibodies that may protect against such viruses. These antibodies are produced mostly against carbohydrate antigens on gastrointestinal bacteria and fortuitously, they bind to carbohydrate antigens synthesized in other mammals, neutralize and destroy viruses presenting these antigens. Two such antibodies are: anti-Gal binding to α-gal epitopes synthesized in non-primate mammals, lemurs, and New World monkeys, and anti-N-glycolyl neuraminic acid (anti-Neu5Gc) binding to N-glycolyl-neuraminic acid (Neu5Gc) synthesized in apes, Old World monkeys, and many non-primate mammals. Anti-Gal appeared in Old World primates following accidental inactivation of the α1,3galactosyltransferase gene 20-30 million years ago. Anti-Neu5Gc appeared in hominins following the inactivation of the cytidine-monophosphate-N-acetyl-neuraminic acid hydroxylase gene, which led to the loss of Neu5Gc <6 million-years-ago. It is suggested that an epidemic of a lethal virus eliminated ancestral Old World-primates synthesizing α-gal epitopes, whereas few mutated offspring lacking α-gal epitopes and producing anti-Gal survived because anti-Gal destroyed viruses presenting α-gal epitopes, following replication in parental populations. Similarly, anti-Neu5Gc protected few mutated hominins lacking Neu5Gc in lethal virus epidemics that eliminated parental hominins synthesizing Neu5Gc. Since α-gal epitopes are presented on many zoonotic viruses it is suggested that vaccines elevating anti-Gal titers may be of protective significance in areas endemic for such zoonotic viruses. This protection would be during the non-primate mammal to human virus transmission, but not in subsequent human to human transmission where the virus presents human glycans. In addition, production of viral vaccines presenting multiple α-gal epitopes increases their immunogenicity because of effective anti-Gal-mediated targeting of vaccines to antigen presenting cells for extensive uptake of the vaccine by these cells.


Assuntos
Antígenos Virais/imunologia , Glicoproteínas/imunologia , Viroses/imunologia , Animais , Reações Antígeno-Anticorpo , Evolução Molecular , Galactosiltransferases/genética , Galactosiltransferases/metabolismo , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Primatas
8.
Nat Commun ; 11(1): 4566, 2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32917903

RESUMO

Influenza virus exposures in childhood can establish long-lived memory B cell responses that can be recalled later in life. Here, we complete a large serological survey to elucidate the specificity of antibodies against contemporary H3N2 viruses in differently aged individuals who were likely primed with different H3N2 strains in childhood. We find that most humans who were first infected in childhood with H3N2 viral strains from the 1960s and 1970s possess non-neutralizing antibodies against contemporary 3c2.A H3N2 viruses. We find that 3c2.A H3N2 virus infections boost non-neutralizing H3N2 antibodies in middle-aged individuals, potentially leaving many of them in a perpetual state of 3c2.A H3N2 viral susceptibility.


Assuntos
Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Vírus da Influenza A Subtipo H3N2/imunologia , Influenza Humana/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Neutralizantes/imunologia , Antígenos Virais/imunologia , Criança , Pré-Escolar , Suscetibilidade a Doenças , Feminino , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Philadelphia , Proteínas Recombinantes , Estações do Ano , Adulto Jovem
9.
Vaccine ; 38(42): 6487-6499, 2020 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-32907757

RESUMO

The many carbohydrate chains on Covid-19 coronavirus SARS-CoV-2 and its S-protein form a glycan-shield that masks antigenic peptides and decreases uptake of inactivated virus or S-protein vaccines by APC. Studies on inactivated influenza virus and recombinant gp120 of HIV vaccines indicate that glycoengineering of glycan-shields to present α-gal epitopes (Galα1-3Galß1-4GlcNAc-R) enables harnessing of the natural anti-Gal antibody for amplifying vaccine efficacy, as evaluated in mice producing anti-Gal. The α-gal epitope is the ligand for the natural anti-Gal antibody which constitutes ~1% of immunoglobulins in humans. Upon administration of vaccines presenting α-gal epitopes, anti-Gal binds to these epitopes at the vaccination site and forms immune complexes with the vaccines. These immune complexes are targeted for extensive uptake by APC as a result of binding of the Fc portion of immunocomplexed anti-Gal to Fc receptors on APC. This anti-Gal mediated effective uptake of vaccines by APC results in 10-200-fold higher anti-viral immune response and in 8-fold higher survival rate following challenge with a lethal dose of live influenza virus, than same vaccines lacking α-gal epitopes. It is suggested that glycoengineering of carbohydrate chains on the glycan-shield of inactivated SARS-CoV-2 or on S-protein vaccines, for presenting α-gal epitopes, will have similar amplifying effects on vaccine efficacy. α-Gal epitope synthesis on coronavirus vaccines can be achieved with recombinant α1,3galactosyltransferase, replication of the virus in cells with high α1,3galactosyltransferase activity as a result of stable transfection of cells with several copies of the α1,3galactosyltransferase gene (GGTA1), or by transduction of host cells with replication defective adenovirus containing this gene. In addition, recombinant S-protein presenting multiple α-gal epitopes on the glycan-shield may be produced in glycoengineered yeast or bacteria expression systems containing the corresponding glycosyltransferases. Prospective Covid-19 vaccines presenting α-gal epitopes may provide better protection than vaccines lacking this epitope because of increased uptake by APC.


Assuntos
Antígenos Virais/genética , Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Glicoproteína da Espícula de Coronavírus/genética , Trissacarídeos/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/biossíntese , Antígenos Virais/imunologia , Antígenos Virais/metabolismo , Betacoronavirus/imunologia , Betacoronavirus/patogenicidade , Infecções por Coronavirus/genética , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Células Dendríticas/virologia , Engenharia Genética , Proteína do Núcleo p24 do HIV/química , Proteína do Núcleo p24 do HIV/genética , Proteína do Núcleo p24 do HIV/imunologia , Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/genética , Proteína gp120 do Envelope de HIV/imunologia , Humanos , Imunogenicidade da Vacina , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/virologia , Camundongos , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Trissacarídeos/química , Vacinas Virais/administração & dosagem , Vacinas Virais/biossíntese , Vacinas Virais/genética
10.
Indian J Med Microbiol ; 38(2): 210-212, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32883935

RESUMO

Recent emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and subsequent containment procedures have impacted the world as never seen before. Therefore, there is considerable curiosity about the genome evolution related to the origin, transmission and vaccine impact of this virus. We have analysed genome sequences of SARS-CoV-2 isolated from Indian patients to gain an in-depth understanding of genomic evolution and transmission in India. Phylogenetic analysis and mutation profiling revealed major lineages being evolved by characteristic mutations. As the mutation frequency in spike protein is comparatively lesser, the candidate vaccines expected to have wide coverage worldwide including India.


Assuntos
Antígenos Virais/genética , Betacoronavirus/genética , Infecções por Coronavirus/prevenção & controle , Genoma Viral , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Glicoproteína da Espícula de Coronavírus/genética , Vacinas Virais/genética , Animais , Antígenos Virais/imunologia , Antígenos Virais/metabolismo , Betacoronavirus/classificação , Betacoronavirus/imunologia , Betacoronavirus/patogenicidade , Quirópteros/virologia , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/genética , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/transmissão , Reservatórios de Doenças/virologia , Eutérios/virologia , Evolução Molecular , Humanos , Índia/epidemiologia , Mutação , Filogenia , Pneumonia Viral/epidemiologia , Pneumonia Viral/imunologia , Pneumonia Viral/transmissão , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Vacinas Virais/biossíntese , Vacinas Virais/imunologia
11.
PLoS Pathog ; 16(9): e1008857, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32936838

RESUMO

An outbreak of the hand-foot-mouth disease with severe neurological cases, mainly caused by the genotype C1 enterovirus A71 (EV-A71), occurred in Taiwan between 2018 and early 2019. In the recent decade, the most dominant EV-A71 genotypes in Taiwan were B5 and C4 but changed to C1 in 2018. Antibody-mediated immunity plays a key role in limiting the EV-A71 illness in humans. However, the level of neutralizing activities against genotype C1 virus by human polyclonal and monoclonal antibodies (MAbs) remains largely unclear. In the study, we demonstrated that that 39% (9 in 23) of post-infection sera from the genotype B5- or C4-infected patients in 2014-2017 exhibit reduced titers with the 2018-2019 genotype C1 viruses than with the earlier B5 and C4 viruses tested. This finding with polyclonal sera is confirmed with human MAbs derived from genotype B5 virus-infected individuals. The 2018-2019 genotype C1 virus is resistant to the majority of canyon-targeting human MAbs, which may be associated with the residue change near or at the bottom of the canyon region on the viral capsid. The remaining three antibodies (16-2-11B, 16-3-4D, and 17-1-12A), which target VP1 S241 on the 5-fold vertex, VP3 E81 on the 3-fold plateau and VP2 D84 on the 2-fold plateau of genotype C1 viral capsid, respectively, retained neutralizing activities with variable potencies. These neutralizing antibodies were also found to be protective against a lethal challenge of the 2018-2019 genotype C1 virus in an hSCARB2-transgenic mice model. These results indicate that the EV-A71-specific antibody response may consist of a fraction of poorly neutralizing antibodies against 2018-2019 genotype C1 viruses among a subset of previously infected individuals. Epitope mapping of protective antibodies that recognize the emerging genotype C1 virus has implications for anti-EV-A71 MAbs and the vaccine field.


Assuntos
Antígenos Virais/genética , Enterovirus Humano A/genética , Variação Genética , Genoma Viral , Genótipo , Doença de Mão, Pé e Boca/genética , Animais , Anticorpos Neutralizantes/genética , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/genética , Anticorpos Antivirais/imunologia , Antígenos Virais/imunologia , Criança , Pré-Escolar , Enterovirus Humano A/imunologia , Enterovirus Humano A/isolamento & purificação , Feminino , Doença de Mão, Pé e Boca/epidemiologia , Doença de Mão, Pé e Boca/imunologia , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Taiwan
12.
PLoS Pathog ; 16(8): e1008732, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32750093

RESUMO

Rotavirus is a major cause of gastroenteritis in children, with infection typically inducing high levels of protective antibodies. Antibodies targeting the middle capsid protein VP6 are particularly abundant, and as VP6 is only exposed inside cells, neutralisation must be post-entry. However, while a system of poly immune globulin receptor (pIgR) transcytosis has been proposed for anti-VP6 IgAs, the mechanism by which VP6-specific IgG mediates protection remains less clear. We have developed an intracellular neutralisation assay to examine how antibodies neutralise rotavirus inside cells, enabling comparison between IgG and IgA isotypes. Unexpectedly we found that neutralisation by VP6-specific IgG was much more efficient than by VP6-specific IgA. This observation was highly dependent on the activity of the cytosolic antibody receptor TRIM21 and was confirmed using an in vivo model of murine rotavirus infection. Furthermore, mice deficient in only IgG and not other antibody isotypes had a serious deficit in intracellular antibody-mediated protection. The finding that VP6-specific IgG protect mice against rotavirus infection has important implications for rotavirus vaccination. Current assays determine protection in humans predominantly by measuring rotavirus-specific IgA titres. Measurements of VP6-specific IgG may add to existing mechanistic correlates of protection.


Assuntos
Anticorpos Antivirais/imunologia , Antígenos Virais/imunologia , Proteínas do Capsídeo/imunologia , Imunoglobulina G/imunologia , Infecções por Rotavirus/imunologia , Rotavirus/fisiologia , Animais , Antígenos Virais/genética , Proteínas do Capsídeo/genética , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Rotavirus/genética , Infecções por Rotavirus/virologia , Especificidade da Espécie
13.
J Clin Virol ; 130: 104572, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32769024

RESUMO

BACKGROUND: The emergence of SARS-CoV-2 has led to the development of serological assays that could aid in an understanding of the burden of COVID-19 disease. Many available tests lack rigorous evaluation and therefore results may be misleading. OBJECTIVES: The aim of this study was to assess the performance of a novel multiplexed immunoassay for the simultaneous detection of antibodies against SARS-CoV-2 trimeric spike (S), spike receptor binding domain (RBD), spike N terminal domain and nucleocapsid antigen and a novel pseudo-neutralisation assay. METHODS: A multiplexed solid-phase chemiluminescence assay (Meso Scale Discovery) was evaluated for the simultaneous detection of IgG binding to four SARS-CoV-2 antigens and the quantification of antibody-induced ACE-2 binding inhibition (pseudo-neutralisation assay). Sensitivity was evaluated with a total of 196 COVID-19 serum samples (169 confirmed PCR positive and 27 anti-nucleocapsid IgG positive) from individuals with mild symptomatic or asymptomatic disease. Specificity was evaluated with 194 control serum samples collected from adults prior to December 2019. RESULTS: The specificity and sensitivity of the binding IgG assay was highest for S protein with a specificity of 97.4 % and sensitivity of 96.2 % for samples taken 14 days and 97.9 % for samples taken 21 days following the onset of symptoms. IgG concentration to S and RBD correlated strongly with percentage inhibition measured by the pseudo-neutralisation assay. CONCLUSION: Excellent sensitivity for IgG detection was obtained over 14 days since onset of symptoms for three SARS-CoV-2 antigens (S, RBD and N) in this multiplexed assay which can also measure antibody functionality.


Assuntos
Anticorpos Antivirais/sangue , Antígenos Virais/imunologia , Infecções por Coronavirus/diagnóstico , Imunoensaio/métodos , Imunoglobulina G/sangue , Pneumonia Viral/diagnóstico , Adulto , Betacoronavirus , Técnicas de Laboratório Clínico , Infecções por Coronavirus/imunologia , Feminino , Humanos , Medições Luminescentes/métodos , Masculino , Pessoa de Meia-Idade , Proteínas do Nucleocapsídeo/imunologia , Pandemias , Pneumonia Viral/imunologia , Sensibilidade e Especificidade , Glicoproteína da Espícula de Coronavírus/imunologia
14.
Signal Transduct Target Ther ; 5(1): 156, 2020 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-32796814

RESUMO

The global Coronavirus disease 2019 (COVID-19) pandemic caused by SARS-CoV-2 has affected more than eight million people. There is an urgent need to investigate how the adaptive immunity is established in COVID-19 patients. In this study, we profiled adaptive immune cells of PBMCs from recovered COVID-19 patients with varying disease severity using single-cell RNA and TCR/BCR V(D)J sequencing. The sequencing data revealed SARS-CoV-2-specific shuffling of adaptive immune repertories and COVID-19-induced remodeling of peripheral lymphocytes. Characterization of variations in the peripheral T and B cells from the COVID-19 patients revealed a positive correlation of humoral immune response and T-cell immune memory with disease severity. Sequencing and functional data revealed SARS-CoV-2-specific T-cell immune memory in the convalescent COVID-19 patients. Furthermore, we also identified novel antigens that are responsive in the convalescent patients. Altogether, our study reveals adaptive immune repertories underlying pathogenesis and recovery in severe versus mild COVID-19 patients, providing valuable information for potential vaccine and therapeutic development against SARS-CoV-2 infection.


Assuntos
Linfócitos B/imunologia , Betacoronavirus/patogenicidade , Infecções por Coronavirus/imunologia , Imunidade Celular , Imunidade Humoral , Pneumonia Viral/imunologia , Linfócitos T/imunologia , Antígenos Virais/genética , Antígenos Virais/imunologia , Linfócitos B/classificação , Linfócitos B/virologia , Betacoronavirus/imunologia , Estudos de Casos e Controles , China , Convalescença , Infecções por Coronavirus/genética , Infecções por Coronavirus/patologia , Infecções por Coronavirus/virologia , Progressão da Doença , Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Interações Hospedeiro-Patógeno/imunologia , Humanos , Memória Imunológica , Pandemias , Pneumonia Viral/genética , Pneumonia Viral/patologia , Pneumonia Viral/virologia , Receptores de Antígenos de Linfócitos B/classificação , Receptores de Antígenos de Linfócitos B/genética , Receptores de Antígenos de Linfócitos B/imunologia , Receptores de Antígenos de Linfócitos T/classificação , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/imunologia , Índice de Gravidade de Doença , Análise de Célula Única , Linfócitos T/classificação , Linfócitos T/virologia
15.
Ann Diagn Pathol ; 48: 151600, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32805515

RESUMO

The vaccine BCG has been reported to offer protection against SARS-CoV-2 infection. It has been hypothesized this is based on nonspecific enhancement of innate immunity. This study addressed whether there is strong homology between a SARS-CoV-2 capsid protein and a Mycobacterium bovis protein that would allow for stronger, more specific immune protection. The study also showed the utility of immunohistochemistry in the diagnostic pathology laboratory for elucidating this information. Immunohistochemistry documented that an antibody directed against the SARS-CoV-2 envelope, but not the spike or membrane proteins, strongly cross hybridized to 11/11 Mycobacterial species tested, including M. bovis. BlastP analysis showed high homology of the SARS-CoV-2 envelope protein with 12 consecutive amino acids of the protein LytR C, which is a consensus protein unique to Mycobacteria. Six additional cases of human tuberculosis with few organisms showed that the viral envelope specific antibody (5/6) was more accurate than the AFB stain (2/6) for diagnostic purposes. These data indicate BCG vaccination induces a specific immunity against SARS CoV-2 that targets the viral envelope protein that is essential for infectivity. Thus, a concurrent booster or first use of the BCG vaccine may reduce the severity of the current COVID-19 pandemic. The data also suggests the value of using the SARS-CoV-2 envelope antibody in the diagnosis of Mycobacterial infections in formalin fixed, paraffin embedded tissues by the diagnostic pathologist.


Assuntos
Antígenos Virais/imunologia , Vacina BCG/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/imunologia , Mycobacterium/imunologia , Pneumonia Viral/imunologia , Tuberculose/imunologia , Anticorpos Antivirais/imunologia , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Reações Cruzadas , Humanos , Imuno-Histoquímica/métodos , Pandemias , Tuberculose/diagnóstico , Proteínas do Envelope Viral/imunologia
16.
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
17.
Arch Virol ; 165(10): 2367-2372, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32757058

RESUMO

Mammalian orthoreoviruses (MRVs) infect almost all mammals, and there are some reports on MRVs in China. In this study, a novel strain was identified, which was designated as HLJYC2017. The results of genetic analysis showed that MRV HLJYC2017 is a reassortant strain. According to biological information analysis, different serotypes of MRV contain specific amino acid insertions and deletions in the σ1 protein. Neutralizing antibody epitope analysis revealed partial cross-protection among MRV1, MRV2, and MRV3 isolates from China. L3 gene recombination in MRV was identified for the first time in this study. The results of this study provide valuable information on MRV reassortment and evolution.


Assuntos
Antígenos Virais/genética , Proteínas do Capsídeo/genética , Orthoreovirus de Mamíferos/genética , Vírus Reordenados/genética , Infecções por Reoviridae/epidemiologia , Infecções por Reoviridae/veterinária , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Antígenos Virais/imunologia , Proteínas do Capsídeo/imunologia , China/epidemiologia , Quirópteros , Cervos , Fezes/virologia , Expressão Gênica , Mutação INDEL , Camundongos , Epidemiologia Molecular , Orthoreovirus de Mamíferos/classificação , Orthoreovirus de Mamíferos/imunologia , Orthoreovirus de Mamíferos/isolamento & purificação , Filogenia , RNA Viral/genética , Vírus Reordenados/classificação , Vírus Reordenados/imunologia , Vírus Reordenados/isolamento & purificação , Infecções por Reoviridae/imunologia , Infecções por Reoviridae/virologia , Sorogrupo , Suínos
18.
Nat Immunol ; 21(10): 1293-1301, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32807944

RESUMO

The SARS-CoV-2 virus emerged in December 2019 and has caused a worldwide pandemic due to the lack of any pre-existing immunity. Accurate serology testing is urgently needed to help diagnose infection, determine past exposure of populations and assess the response to a future vaccine. The landscape of antibody responses to SARS-CoV-2 is unknown. In this study, we utilized the luciferase immunoprecipitation system to assess the antibody responses to 15 different SARS-CoV-2 antigens in patients with COVID-19. We identified new targets of the immune response to SARS-CoV-2 and show that nucleocapsid, open reading frame (ORF)8 and ORF3b elicit the strongest specific antibody responses. ORF8 and ORF3b antibodies, taken together as a cluster of points, identified 96.5% of COVID-19 samples at early and late time points of disease with 99.5% specificity. Our findings could be used to develop second-generation diagnostic tests to improve serological assays for COVID-19 and are important in understanding pathogenicity.


Assuntos
Anticorpos Antivirais/sangue , Betacoronavirus/imunologia , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Proteínas Virais/imunologia , Adulto , Idoso , Anticorpos Antivirais/imunologia , Antígenos Virais/imunologia , Infecções por Coronavirus/sangue , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Feminino , Hong Kong , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/sangue , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Sensibilidade e Especificidade , Fatores de Tempo
19.
Emerg Microbes Infect ; 9(1): 1965-1973, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32819220

RESUMO

Serology is a crucial part of the public health response to the ongoing SARS-CoV-2 pandemic. Here, we describe the development, validation and clinical evaluation of a protein micro-array as a quantitative multiplex immunoassay that can identify S and N-directed SARS-CoV-2 IgG antibodies with high specificity and sensitivity and distinguish them from all currently circulating human coronaviruses. The method specificity was 100% for SARS-CoV-2 S1 and 96% for N antigen based on extensive syndromic (n=230 cases) and population panel (n=94) testing that also confirmed the high prevalence of seasonal human coronaviruses. To assess its potential role for both SARS-CoV-2 patient diagnostics and population studies, we evaluated a large heterogeneous COVID-19 cohort (n=330) and found an overall sensitivity of 89% (≥ 21 days post onset symptoms (dps)), ranging from 86% to 96% depending on severity of disease. For a subset of these patients longitudinal samples were provided up to 56 dps. Mild cases showed absent or delayed, and lower SARS-CoV-2 antibody responses. Overall, we present the development and extensive clinical validation of a multiplex coronavirus serological assay for syndromic testing, to answer research questions regarding to antibody responses, to support SARS-CoV-2 diagnostics and to evaluate epidemiological developments efficiently and with high-throughput.


Assuntos
Anticorpos Antivirais/sangue , Betacoronavirus/imunologia , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Proteínas do Nucleocapsídeo/sangue , Pneumonia Viral/diagnóstico , Glicoproteína da Espícula de Coronavírus/sangue , Idoso , Antígenos Virais/sangue , Antígenos Virais/imunologia , Betacoronavirus/patogenicidade , Técnicas de Laboratório Clínico/normas , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/mortalidade , Infecções por Coronavirus/virologia , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Coronavírus da Síndrome Respiratória do Oriente Médio/imunologia , Coronavírus da Síndrome Respiratória do Oriente Médio/patogenicidade , Testes de Neutralização , Proteínas do Nucleocapsídeo/imunologia , Pandemias , Pneumonia Viral/imunologia , Pneumonia Viral/mortalidade , Pneumonia Viral/virologia , Análise Serial de Proteínas , Vírus da SARS/imunologia , Vírus da SARS/patogenicidade , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Glicoproteína da Espícula de Coronavírus/imunologia
20.
Comput Biol Med ; 124: 103967, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32828069

RESUMO

AIMS: With a large number of fatalities, coronavirus disease-2019 (COVID-19) has greatly affected human health worldwide. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the virus that causes COVID-19. The World Health Organization has declared a global pandemic of this contagious disease. Researchers across the world are collaborating in a quest for remedies to combat this deadly virus. It has recently been demonstrated that the spike glycoprotein (SGP) of SARS-CoV-2 is the mediator by which the virus enters host cells. MAIN METHODS: Our group comprehensibly analyzed the SGP of SARS-CoV-2 through multiple sequence analysis and a phylogenetic analysis. We predicted the strongest immunogenic epitopes of the SGP for both B cells and T cells. KEY FINDINGS: We focused on predicting peptides that would bind major histocompatibility complex class I. Two optimal epitopes were identified, WTAGAAAYY and GAAAYYVGY. They interact with the HLA-B*15:01 allele, which was further validated by molecular docking simulation. This study also found that the selected epitopes are able to be recognized in a large percentage of the world's population. Furthermore, we predicted CD4+ T-cell epitopes and B-cell epitopes. SIGNIFICANCE: Our study provides a strong basis for designing vaccine candidates against SARS-CoV-2. However, laboratory work is required to validate our theoretical results, which would lay the foundation for the appropriate vaccine manufacturing and testing processes.


Assuntos
Betacoronavirus , Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinas Virais/imunologia , Sequência de Aminoácidos , Antígenos Virais/química , Antígenos Virais/genética , Antígenos Virais/imunologia , Betacoronavirus/genética , Betacoronavirus/imunologia , Biologia Computacional , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/genética , Infecções por Coronavirus/imunologia , Desenho de Fármacos , Epitopos de Linfócito B/química , Epitopos de Linfócito B/genética , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/química , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Antígeno HLA-B15/química , Antígeno HLA-B15/metabolismo , Cadeias HLA-DRB1/química , Cadeias HLA-DRB1/metabolismo , Humanos , Simulação de Acoplamento Molecular , Pneumonia Viral/epidemiologia , Pneumonia Viral/imunologia , Vacinas Virais/química , Vacinas Virais/genética
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