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1.
Immunity ; 54(2): 340-354.e6, 2021 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-33567252

RESUMO

Cellular and humoral immunity to SARS-CoV-2 is critical to control primary infection and correlates with severity of disease. The role of SARS-CoV-2-specific T cell immunity, its relationship to antibodies, and pre-existing immunity against endemic coronaviruses (huCoV), which has been hypothesized to be protective, were investigated in 82 healthy donors (HDs), 204 recovered (RCs), and 92 active COVID-19 patients (ACs). ACs had high amounts of anti-SARS-CoV-2 nucleocapsid and spike IgG but lymphopenia and overall reduced antiviral T cell responses due to the inflammatory milieu, expression of inhibitory molecules (PD-1, Tim-3) as well as effector caspase-3, -7, and -8 activity in T cells. SARS-CoV-2-specific T cell immunity conferred by polyfunctional, mainly interferon-γ-secreting CD4+ T cells remained stable throughout convalescence, whereas humoral responses declined. Immune responses toward huCoV in RCs with mild disease and strong cellular SARS-CoV-2 T cell reactivity imply a protective role of pre-existing immunity against huCoV.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Imunidade Celular/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Feminino , Humanos , Imunidade Humoral/imunologia , Masculino , Pessoa de Meia-Idade , Adulto Jovem
2.
Nat Commun ; 12(1): 1018, 2021 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-33589636

RESUMO

Antibodies serve as biomarkers of infection, but if sustained can confer long-term immunity. Yet, for most clinically approved vaccines, binding antibody titers only serve as a surrogate of protection. Instead, the ability of vaccine induced antibodies to neutralize or mediate Fc-effector functions is mechanistically linked to protection. While evidence has begun to point to persisting antibody responses among SARS-CoV-2 infected individuals, cases of re-infection have begun to emerge, calling the protective nature of humoral immunity against this highly infectious pathogen into question. Using a community-based surveillance study, we aimed to define the relationship between titers and functional antibody activity to SARS-CoV-2 over time. Here we report significant heterogeneity, but limited decay, across antibody titers amongst 120 identified seroconverters, most of whom had asymptomatic infection. Notably, neutralization, Fc-function, and SARS-CoV-2 specific T cell responses were only observed in subjects that elicited RBD-specific antibody titers above a threshold. The findings point to a switch-like relationship between observed antibody titer and function, where a distinct threshold of activity-defined by the level of antibodies-is required to elicit vigorous humoral and cellular response. This response activity level may be essential for durable protection, potentially explaining why re-infections occur with SARS-CoV-2 and other common coronaviruses.


Assuntos
Anticorpos Antivirais/imunologia , /imunologia , Adolescente , Adulto , Idoso , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/sangue , Feminino , Humanos , Imunidade Humoral/imunologia , Imunoglobulina G/imunologia , Masculino , Pessoa de Meia-Idade , Glicoproteína da Espícula de Coronavírus/imunologia , Linfócitos T/imunologia , Vacinas Virais/imunologia , Adulto Jovem
3.
Cell Rep ; 34(7): 108737, 2021 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-33545052

RESUMO

In the ongoing coronavirus disease 2019 (COVID-19) pandemic, there remain unanswered questions regarding the nature and significance of the humoral immune response toward other coronavirus infections. Here, we investigate the cross-reactivity of antibodies raised against the first severe acute respiratory syndrome coronavirus (SARS-CoV) for their reactivity toward SARS-CoV-2. We extensively characterize a selection of 10 antibodies covering all of the SARS-CoV structural proteins: spike, membrane, nucleocapsid, and envelope. Although nearly all of the examined SARS-CoV antibodies display some level of reactivity to SARS-CoV-2, we find only partial cross-neutralization for the spike antibodies. The implications of our work are two-fold. First, we establish a set of antibodies with known reactivity to both SARS-CoV and SARS-CoV-2, which will allow further study of both viruses. Second, we provide empirical evidence of the high propensity for antibody cross-reactivity between distinct strains of human coronaviruses, which is critical information for designing diagnostic and vaccine strategies for COVID-19.


Assuntos
Anticorpos Antivirais/imunologia , Vírus da SARS/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , /imunologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Reações Cruzadas/imunologia , Células HEK293 , Humanos , Imunidade Humoral/imunologia , Pandemias , Vírus da SARS/genética , Glicoproteína da Espícula de Coronavírus/genética
4.
Arch Virol ; 166(2): 571-579, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33410993

RESUMO

This study compared concurrent and separate primary vaccination against equid alphaherpesviruses 1 and 4, genus Varicellovirus, subfamily Alphaherpesvirinae, family Herpesviridae, and equine influenza A virus, genus Alphainfluenzavirus, family Orthomyxoviridae. Their vernacular names are equine herpesvirus 1 and 4 (EHV1/4) and equine influenza virus (EIV). Infection with these respiratory pathogens is associated with loss of performance, interruption of training schedules, and on occasion, cancellation of equestrian events. Vaccination is highly recommended, and for some activities it is a mandatory requirement of the relevant authority. As there is a dearth of information relating to the impact of concurrent vaccination on the antibody response to EHV and EIV vaccines, they are usually administered separately, often 2 weeks apart. In a previous study of booster vaccination in Thoroughbred racehorses, concurrent vaccination with whole-virus inactivated carbopol-adjuvanted EHV and EIV vaccines did not impact negatively on the antibody response. In this study, investigations were extended to concurrent versus separate primary vaccination of warmblood foals. A field study was conducted to compare the immune response to a carbopol-adjuvanted EHV vaccine and an immune stimulating complex (ISCOM)-adjuvanted EI vaccine administered concurrently and 2 weeks apart. No adverse clinical reactions were observed, the pattern of EI and EHV antibody response was similar for both groups, and there was no evidence that concurrent primary vaccination compromised the humoral response. The results are of relevance to horse owners who wish to decrease veterinary costs, limit handling of young animals, and simplify record keeping by vaccinating concurrently.


Assuntos
Infecções por Herpesviridae/imunologia , Vacinas contra Herpesvirus/imunologia , Doenças dos Cavalos/imunologia , Cavalos/imunologia , Vírus da Influenza A/imunologia , Vacinas contra Influenza/imunologia , Adjuvantes Imunológicos/administração & dosagem , Animais , Anticorpos Antivirais/imunologia , Formação de Anticorpos/imunologia , Feminino , Doenças dos Cavalos/virologia , Cavalos/virologia , Imunidade Humoral/imunologia , Imunização Secundária/métodos , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/virologia , Vacinação/métodos , Vacinas de Produtos Inativados/imunologia
5.
Analyst ; 146(2): 382-402, 2021 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-33410826

RESUMO

The new outbreak caused by coronavirus SARS-CoV-2 started at the end of 2019 and was declared a pandemic in March 2020. Since then, several diagnostic approaches have been re-adapted, and also improved from the previous detections of SARS and MERS coronavirus. The best strategy to handle this situation seems to rely on a triad of detection methods: (i) highly sensitive and specific techniques as the gold standard method, (ii) easier and faster point of care tests accessible for large population screening, and (iii) serology assays to complement the direct detection and to use for surveillance. In this study, we assessed the techniques and tests described in the literature, their advantages and disadvantages, and the interpretation of the results. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) is undoubtedly the gold standard technique utilized not only for diagnostics, but also as a standard for comparison and validation of newer approaches. Other nucleic acid amplification methods have been shown to be adequate as point of care (POC) diagnostic tests with similar performance as RT-qPCR. The analysis of seroconversion with immunotests shows the complexity of the immune response to COVID-19. The detection of anti-SARS-CoV-2 antibodies can also help to detect previously infected asymptomatic individuals with negative RT-qPCR tests. Nevertheless, more controlled serology cohort studies should be performed as soon as possible to understand the immune response to SARS-CoV-2.


Assuntos
/métodos , Imunidade Humoral/imunologia , Testes Imediatos/normas , /imunologia , /imunologia , Técnicas de Laboratório Clínico/métodos , Humanos , Técnicas de Amplificação de Ácido Nucleico/métodos
6.
Int J Mol Sci ; 22(2)2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33430234

RESUMO

CD4+ T cells orchestrate adaptive immune responses through their capacity to recruit and provide help to multiple immune effectors, in addition to exerting direct effector functions. CD4+ T cells are increasingly recognized as playing an essential role in the control of chronic viral infections. In this review, we present recent advances in understanding the nature of CD4+ T cell help provided to antiviral effectors. Drawing from our studies of natural human immunodeficiency virus (HIV) control, we then focus on the role of high-affinity T cell receptor (TCR) clonotypes in mediating antiviral CD4+ T cell responses. Last, we discuss the role of TCR affinity in determining CD4+ T cell differentiation, reviewing the at times divergent studies associating TCR signal strength to the choice of a T helper 1 (Th1) or a T follicular helper (Tfh) cell fate.


Assuntos
Infecções por HIV/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , /imunologia , Imunidade Adaptativa/imunologia , Linfócitos T CD8-Positivos/imunologia , Diferenciação Celular/imunologia , Infecções por HIV/virologia , Humanos , Imunidade Humoral/imunologia , Linfócitos T Reguladores/imunologia
7.
Nat Commun ; 12(1): 541, 2021 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-33483492

RESUMO

CD4 T follicular helper (Tfh) cells are important for the generation of durable and specific humoral protection against viral infections. The degree to which SARS-CoV-2 infection generates Tfh cells and stimulates the germinal center (GC) response is an important question as we investigate vaccine induced immunity against COVID-19. Here, we report that SARS-CoV-2 infection in rhesus macaques, either infused with convalescent plasma, normal plasma, or receiving no infusion, resulted in transient accumulation of pro-inflammatory monocytes and proliferating Tfh cells with a Th1 profile in peripheral blood. CD4 helper cell responses skewed predominantly toward a Th1 response in blood, lung, and lymph nodes. SARS-CoV-2 Infection induced GC Tfh cells specific for the SARS-CoV-2 spike and nucleocapsid proteins, and a corresponding early appearance of antiviral serum IgG antibodies. Collectively, the data show induction of GC responses in a rhesus model of mild COVID-19.


Assuntos
/imunologia , Centro Germinativo/imunologia , /imunologia , Células Th1/imunologia , Animais , Anticorpos Antivirais/sangue , Linhagem Celular , Chlorocebus aethiops , Modelos Animais de Doenças , Feminino , Humanos , Imunidade Humoral/imunologia , Imunização Passiva , Imunogenicidade da Vacina/imunologia , Imunoglobulina G/sangue , Macaca mulatta , Masculino , Fosfoproteínas/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Células Vero
8.
Sci Rep ; 11(1): 2608, 2021 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-33510275

RESUMO

The protective effect of neutralizing antibodies in SARS-CoV-2 infected individuals is not yet well defined. To address this issue, we have analyzed the kinetics of neutralizing antibody responses and their association with disease severity. Between March and May 2020, the prospective KING study enrolled 72 COVID-19+ participants grouped according to disease severity. SARS-CoV-2 infection was diagnosed by serological and virological tests. Plasma neutralizing responses were assessed against replicative virus and pseudoviral particles. Multiple regression and non-parametric tests were used to analyze dependence of parameters. The magnitude of neutralizing titers significantly increased with disease severity. Hospitalized individuals developed higher titers compared to mild-symptomatic and asymptomatic individuals, which together showed titers below the detection limit in 50% of cases. Longitudinal analysis confirmed the strong differences in neutralizing titers between non-hospitalized and hospitalized participants and showed rapid kinetics of appearance of neutralizing antibodies (50% and 80% of maximal activity reached after 11 and 17 days after symptoms onset, respectively) in hospitalized patients. No significant impact of age, gender or treatment on the neutralizing titers was observed in this limited cohort. These data identify a clear association of humoral immunity with disease severity and point to immune mechanisms other than antibodies as relevant players in COVID-19 protection.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , /imunologia , Imunidade Adaptativa/imunologia , Adulto , Anticorpos Neutralizantes/sangue , Estudos de Coortes , Feminino , Humanos , Imunidade Humoral/imunologia , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Índice de Gravidade de Doença , Espanha/epidemiologia
9.
Artigo em Inglês | MEDLINE | ID: mdl-33361386

RESUMO

OBJECTIVE: To discuss the pathogenic and diagnostic relevance of cellular and humoral immune responses against severe acute respiratory syndrome novel coronavirus (SARS-COV-2) and pertinent observations made in progressive multifocal leukoencephalopathy (PML). METHODS: Review of pertinent literature. RESULTS: There is at least 1 precedent for an antibody response against a viral pathogen that fails to provide host protection in the absence of immune-competent CD4+ T cells. PML is an infection of the CNS caused by JC virus (JCV), which commonly occurs during treatment with the therapeutic monoclonal antibody natalizumab. In this context, the humoral immune response fails to prevent JCV reactivation, and elevated anti-JCV serum indices are associated with a higher PML incidence. The more relevant immune-competent cells in host defense against JCV appear to be T cells. T cell-mediated responses are also detectable in convalescing patients with SARS-COV-2 irrespective of the humoral immune response. CONCLUSION: Based on pathogenic lessons learned from PML under natalizumab therapy, we suggest the incorporation of functional assays that determine neutralizing properties of SARS-CoV-2-specific antibodies. In addition, we outline the potential role of T-cell detection assays in determining herd immunity in a given population or in studying therapeutic responses to vaccines.


Assuntos
Imunidade Adaptativa/imunologia , Anticorpos Antivirais/imunologia , Formação de Anticorpos/imunologia , Imunidade Humoral/imunologia , Leucoencefalopatia Multifocal Progressiva/imunologia , Linfócitos T/imunologia , Humanos , Leucoencefalopatia Multifocal Progressiva/tratamento farmacológico
10.
Int J Nanomedicine ; 15: 10321-10330, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33364759

RESUMO

Background: Vaccination provides a viable alternative to antibiotics for the treatment of drug-resistant bacterial infection. Bacterial protoplasts have gained much attention for a new generation vaccine due to depleting toxic outer wall components. Purpose: The objective of this study was to reveal the effects of bacterial protoplast-derived nanovesicles (PDNVs) size on antibacterial immunity. Methods: Herein, we prepared bacterial PDNVs with different sizes by removing the cell wall of Staphylococcus aureus (S. aureus) to generate multi-antigen nanovaccines. Furthermore, we investigated the ability of PDNVs in different sizes to activate dendritic cells (DCs) and trigger humoral and cellular immune responses in vivo. Results: We obtained particles of ∼200 nm, 400 nm, and 700 nm diameters and found that all the PDNVs readily induce efficient maturation of DCs in the draining lymph nodes of the vaccinated mice. Dramatically, the activation of DCs was increased with decreasing particle sizes. In addition, vaccination with PDNVs generated elevated expression levels of specific antibody and the production of INF-γ, especially the smaller ones, indicating the capability of inducing strong humoral immunity and Th1 biased cell responses against the source bacteria. Conclusion: These observed results provide evidence for size-dependent orchestration of immune responses of PDNVs and help to rationally design and develop effective antibacterial vaccines.


Assuntos
Vacinas Bacterianas/química , Vacinas Bacterianas/imunologia , Protoplastos/química , Staphylococcus aureus/citologia , Staphylococcus aureus/imunologia , Animais , Células Dendríticas/imunologia , Imunidade Celular/imunologia , Imunidade Humoral/imunologia , Camundongos , Nanoestruturas/química
11.
Signal Transduct Target Ther ; 5(1): 294, 2020 12 24.
Artigo em Inglês | MEDLINE | ID: mdl-33361761

RESUMO

Understanding the processes of immune regulation in patients infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is crucial for improving treatment. Here, we performed longitudinal whole-transcriptome RNA sequencing on peripheral blood mononuclear cell (PBMC) samples from 18 patients with coronavirus disease 2019 (COVID-19) during their treatment, convalescence, and rehabilitation. After analyzing the regulatory networks of differentially expressed messenger RNAs (mRNAs), microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) between the different clinical stages, we found that humoral immunity and type I interferon response were significantly downregulated, while robust T-cell activation and differentiation at the whole transcriptome level constituted the main events that occurred during recovery from COVID-19. The formation of this T cell immune response might be driven by the activation of activating protein-1 (AP-1) related signaling pathway and was weakly affected by other clinical features. These findings uncovered the dynamic pattern of immune responses and indicated the key role of T cell immunity in the creation of immune protection against this disease.


Assuntos
/genética , Imunidade Humoral/genética , Linfócitos T/metabolismo , Transcriptoma/genética , /epidemiologia , Feminino , Humanos , Imunidade Humoral/imunologia , Leucócitos Mononucleares/metabolismo , Masculino , MicroRNAs , RNA Longo não Codificante/genética , RNA-Seq , /patogenicidade , Linfócitos T/imunologia , Linfócitos T/patologia , Fator de Transcrição AP-1/genética
12.
Commun Biol ; 3(1): 780, 2020 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-33311543

RESUMO

Coronavirus Disease 2019 (COVID-19) has caused a global pandemic. Here we profiled the humoral response against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) by measuring immunoglobulin (Ig) A, IgM, and IgG against nucleocapsid and spike proteins, along with IgM and IgG antibodies against receptor-binding domain (RBD) of the spike protein and total neutralizing antibodies (NAbs). We tested 279 plasma samples collected from 176 COVID-19 patients who presented and enrolled at different stages of their disease. Plasma dilutions were optimized and based on the data, a single dilution of plasma was used. The mean absorbance at 450 nm was measured for Ig levels and NAbs were measured using geometric mean titers. We demonstrate that more severe cases have a late-onset in the humoral response compared to mild/moderate infections. All the antibody titers continue to rise in patients with COVID-19 over the disease course. However, these levels are mostly unrelated to disease severity. The appearance time and titers of NAbs showed a significant positive correlation to the antibodies against spike protein. Our results suggest the late onset of antibody response as a risk factor for disease severity, however, there is a limited role of antibody titers in predicting disease severity of COVID-19.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Imunidade Humoral/imunologia , /imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , /virologia , China/epidemiologia , Chlorocebus aethiops , Feminino , Humanos , Cinética , Masculino , Pessoa de Meia-Idade , Pandemias , Índice de Gravidade de Doença , Glicoproteína da Espícula de Coronavírus/imunologia , Células Vero , Adulto Jovem
13.
Nat Commun ; 11(1): 6385, 2020 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-33318491

RESUMO

The response to the coronavirus disease 2019 (COVID-19) pandemic has been hampered by lack of an effective severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antiviral therapy. Here we report the use of remdesivir in a patient with COVID-19 and the prototypic genetic antibody deficiency X-linked agammaglobulinaemia (XLA). Despite evidence of complement activation and a robust T cell response, the patient developed persistent SARS-CoV-2 pneumonitis, without progressing to multi-organ involvement. This unusual clinical course is consistent with a contribution of antibodies to both viral clearance and progression to severe disease. In the absence of these confounders, we take an experimental medicine approach to examine the in vivo utility of remdesivir. Over two independent courses of treatment, we observe a temporally correlated clinical and virological response, leading to clinical resolution and viral clearance, with no evidence of acquired drug resistance. We therefore provide evidence for the antiviral efficacy of remdesivir in vivo, and its potential benefit in selected patients.


Assuntos
Monofosfato de Adenosina/análogos & derivados , Alanina/análogos & derivados , Imunidade Humoral/efeitos dos fármacos , /efeitos dos fármacos , Monofosfato de Adenosina/uso terapêutico , Adulto , Alanina/uso terapêutico , Antivirais/uso terapêutico , Febre/prevenção & controle , Humanos , Imunidade Humoral/imunologia , Contagem de Linfócitos , Masculino , /fisiologia , Resultado do Tratamento
14.
Neuroimmunomodulation ; 27(2): 80-86, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33341814

RESUMO

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19) pandemic has affected millions of people worldwide. The pathophysiology of this virus is not very clearly known, thus, enormous efforts are being made by the scientific community to delineate its evading mechanism. In this review, we have summarized the hyperinflammation and humoral and cell-mediated immune response generated in human body after infection with the SARS-CoV-2 virus. The inflammatory response generated after infection by increased proinflammatory cytokines and chemokines, and complement proteins activation may likely contribute to disease severity. We also discussed the other factors that may affect immunity and could be important comorbidities in the disease severity and outcome.


Assuntos
/imunologia , Imunidade Celular/imunologia , Imunidade Humoral/imunologia , Imunidade Inata/imunologia , Inflamação/imunologia , Imunidade Adaptativa/imunologia , Alarminas/imunologia , Linfócitos B/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Ativação do Complemento/imunologia , Síndrome da Liberação de Citocina/imunologia , Humanos , Células Matadoras Naturais/imunologia , Índice de Gravidade de Doença
15.
Clin Lab Med ; 40(4): 603-614, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33121625

RESUMO

The entire spectrum of diagnostic testing, from reagent supply to test performance, has been a major focus during the coronavirus disease 2019 (COVID-19) pandemic. The hope for serologic testing is that it will provide both epidemiologic information about seroprevalence as well as individual information about previous infection. This information is particularly helpful for high-risk individuals who may be outside of the viral shedding window, such as children with suspected multisystem inflammatory syndrome. It is not yet understood whether serologic testing can be interpreted in terms of protective immunity. These concerns must be addressed using highly sensitive and specific tests.


Assuntos
Betacoronavirus , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus , Pandemias , Pneumonia Viral , Estudos Soroepidemiológicos , Betacoronavirus/imunologia , Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Humanos , Imunidade Humoral/imunologia , Pandemias/prevenção & controle , Pneumonia Viral/epidemiologia , Pneumonia Viral/imunologia , Pneumonia Viral/prevenção & controle , Fatores de Proteção , Sensibilidade e Especificidade
16.
Vaccine ; 38(46): 7205-7212, 2020 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-33010978

RESUMO

The development of an effective vaccine against SARS-CoV-2 is urgently needed. We generated SARS-CoV-2 RBD-Fc fusion protein and evaluated its potency to elicit neutralizing antibody response in mice. RBD-Fc elicited a higher neutralizing antibodies titer than RBD as evaluated by a pseudovirus neutralization assay and a live virus based microneutralization assay. Furthermore, RBD-Fc immunized sera better inhibited cell-cell fusion, as evaluated by a quantitative cell-cell fusion assay. The cell-cell fusion assay results correlated well with the virus neutralization potency and could be used for high-throughput screening of large panels of anti-SARS-CoV-2 antibodies and vaccines without the requirement of live virus infection in BSL3 containment. Moreover, the anti-RBD sera did not enhance the pseudotyped SARS-CoV-2 infection of K562 cells. These results demonstrate that Fc fusion can significantly improve the humoral immune response to recombinant RBD immunogen, and suggest that RBD-Fc could serve as a useful component of effective vaccines against SARS-CoV-2.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Infecções por Coronavirus/prevenção & controle , Fragmentos Fc das Imunoglobulinas/imunologia , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Betacoronavirus/imunologia , Fusão Celular , Linhagem Celular , Infecções por Coronavirus/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Células HEK293 , Ensaios de Triagem em Larga Escala/métodos , Humanos , Imunidade Humoral/imunologia , Fragmentos Fc das Imunoglobulinas/genética , Camundongos , Camundongos Endogâmicos BALB C , Testes de Neutralização , Peptidil Dipeptidase A/genética , Domínios Proteicos/imunologia , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Vacinas de Subunidades/imunologia
17.
Hum Immunol ; 81(10-11): 588-595, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32888767

RESUMO

Coronavirus Disease 2019 (COVID-19) is a dangerous global threat that has no clinically approved treatment yet. Bioinformatics represent an outstanding approach to reveal key immunogenic regions in viral proteins. Here, five severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) non-structural proteins (NSPs) (NSP7, NSP8, NSP9, NSP12, and NSP13) were screened to identify potential human leukocyte antigen (HLA) binding peptides. These peptides showed robust viral antigenicity, immunogenicity, and a marked interaction with HLA alleles. Interestingly, several peptides showed affinity by HLA class I (HLA-I) alleles that commonly activates to natural killer (NK) cells. Notably, HLA biding peptides are conserved among SARS-CoV-2, severe acute respiratory syndrome coronavirus (SARS-CoV), and Middle Eastern respiratory syndrome coronavirus (MERS-CoV). Interestingly, HLA-I and HLA class II (HLA-II) binding peptides induced humoral and cell-mediated responses after in silico vaccination. These results may open further in vitro and in vivo investigations to develop novel therapeutic strategies against coronaviral infections.


Assuntos
Betacoronavirus/imunologia , Sequência Conservada/imunologia , Infecções por Coronavirus/imunologia , Antígenos HLA/imunologia , Pneumonia Viral/imunologia , Proteínas não Estruturais Virais/imunologia , Sequência de Aminoácidos , Betacoronavirus/genética , Infecções por Coronavirus/sangue , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/terapia , Infecções por Coronavirus/virologia , Antígenos HLA/metabolismo , Humanos , Imunidade Celular/imunologia , Imunidade Humoral/imunologia , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Coronavírus da Síndrome Respiratória do Oriente Médio/genética , Coronavírus da Síndrome Respiratória do Oriente Médio/imunologia , Simulação de Acoplamento Molecular , Pandemias , Pneumonia Viral/sangue , Pneumonia Viral/terapia , Pneumonia Viral/virologia , Vírus da SARS/genética , Vírus da SARS/imunologia , Vacinas de Subunidades/imunologia , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/metabolismo , Vacinas Virais/imunologia
18.
Mol Immunol ; 127: 175-185, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32992149

RESUMO

Preclinical studies require an immune response similar to that of humans in a small animal model that is convenient to operate. Based on genome alignment, tree shrews are small animals considered to be more similar to primates than are rodents, and many human disease models have been established with tree shrews. However, the characteristics of the humoral immune response of tree shrews remain to be elucidated. In this study, the genetic sequence of the heavy chain constant region of tree shrew immunoglobulin (Ig) was complemented, and the results of immunoglobulin domain homology and transcriptome analysis showed that the tree shrew genome encodes only four classes of antibodies and does not encode IgD. The oldest IgM antibody has the highest homology with primates. After the complete sequence of each type of antibody was obtained, the tree shrew antibody protein was further expressed and purified by in vitro recombination, and an IgG quantitative evaluation system was established. The highly effective immuno protective effect induced by HSV-1 infection and the significant bactericidal effect induced by Neisseria meningitidis group C polysaccharide immunization showed that tree shrews exhibited immune responses more similar to humans than to mice. This may provide better predictive value for vaccine preclinical research.


Assuntos
Sistema Imunitário/imunologia , Imunidade Humoral/imunologia , Tupaiidae/imunologia , Sequência de Aminoácidos , Animais , Células CHO , Sequência Conservada , Cricetinae , Cricetulus , DNA Complementar/genética , Feminino , Loci Gênicos , Genoma , Imunoglobulina G/química , Imunoglobulina G/genética , Masculino , Camundongos Endogâmicos BALB C , Filogenia , Proteínas Recombinantes/metabolismo , Especificidade da Espécie , Tupaiidae/genética
19.
Immunity ; 53(3): 524-532.e4, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32783920

RESUMO

As SARS-CoV-2 infections and death counts continue to rise, it remains unclear why some individuals recover from infection, whereas others rapidly progress and die. Although the immunological mechanisms that underlie different clinical trajectories remain poorly defined, pathogen-specific antibodies often point to immunological mechanisms of protection. Here, we profiled SARS-CoV-2-specific humoral responses in a cohort of 22 hospitalized individuals. Despite inter-individual heterogeneity, distinct antibody signatures resolved individuals with different outcomes. Although no differences in SARS-CoV-2-specific IgG levels were observed, spike-specific humoral responses were enriched among convalescent individuals, whereas functional antibody responses to the nucleocapsid were elevated in deceased individuals. Furthermore, this enriched immunodominant spike-specific antibody profile in convalescents was confirmed in a larger validation cohort. These results demonstrate that early antigen-specific and qualitative features of SARS-CoV-2-specific antibodies point to differences in disease trajectory, highlighting the potential importance of functional antigen-specific humoral immunity to guide patient care and vaccine development.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/mortalidade , Proteínas do Nucleocapsídeo/imunologia , Pneumonia Viral/imunologia , Pneumonia Viral/mortalidade , Glicoproteína da Espícula de Coronavírus/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Betacoronavirus/imunologia , Infecções por Coronavirus/sangue , Feminino , Humanos , Imunidade Humoral/imunologia , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Pandemias , Fosfoproteínas , Pneumonia Viral/sangue
20.
Am J Clin Pathol ; 154(5): 610-619, 2020 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-32808976

RESUMO

OBJECTIVES: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serology tests are clinically useful to document prior SARS-CoV-2 infections. Data are urgently needed to select assays with optimal sensitivity at acceptable specificity for antibody detection. METHODS: A comparative evaluation was performed of 7 commercial SARS-CoV-2 serology assays on 171 sera from 135 subjects with polymerase chain reaction-confirmed SARS-CoV-2 infection (71 hospitalized patients and 64 paucisymptomatic individuals). Kinetics of IgA/IgM/IgG seroconversion to viral N and S protein epitopes were studied from 0 to 54 days after onset of symptoms. Cross-reactivity was verified on 57 prepandemic samples. RESULTS: Wantai SARS-COV-2 Ab ELISA and Orient Gene COVID-19 IgG/IgM Rapid Test showed superior overall sensitivity for detection of SARS-CoV-2 antibodies. Elecsys Anti-SARS-CoV-2 assay and EUROIMMUN Anti-SARS-CoV-2 combined IgG/IgA showed acceptable sensitivity (>95%) vs the consensus result of all assays from 10 days post onset of symptoms. Wantai SARS-COV-2 Ab ELISA, Elecsys Anti-SARS-CoV-2 assay, and Innovita 2019-nCoV Ab rapid test showed least cross-reactivity, resulting in an optimal analytical specificity greater than 98%. CONCLUSIONS: Wantai SARS-COV-2 Ab ELISA and Elecsys Anti-SARS-CoV-2 assays are suitable for sensitive and specific detection of SARS-CoV-2 antibodies from 10 days after onset of symptoms.


Assuntos
Betacoronavirus/patogenicidade , Infecções por Coronavirus/diagnóstico , Imunidade Humoral/imunologia , Pneumonia Viral/diagnóstico , Vírus da SARS/imunologia , Técnicas de Laboratório Clínico , Infecções por Coronavirus/imunologia , Humanos , Pandemias , Pneumonia Viral/imunologia , Sensibilidade e Especificidade , Testes Sorológicos/métodos
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