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1.
Int J Mol Sci ; 22(11)2021 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-34205175

RESUMO

The FcγRIIA/CD32A is mainly expressed on platelets, myeloid and several endothelial cells. Its affinity is considered insufficient for allowing significant binding of monomeric IgG, while its H131R polymorphism (histidine > arginine at position 131) influences affinity for multimeric IgG2. Platelet FcγRIIA has been reported to contribute to IgG-containing immune-complexe clearance. Given our finding that platelet FcγRIIA actually binds monomeric IgG, we investigated the role of platelets and FcγRIIA in IgG antibody elimination. We used pharmacokinetics analysis of infliximab (IgG1) in individuals with controlled Crohn's disease. The influence of platelet count and FcγRIIA polymorphism was quantified by multivariate linear modelling. The infliximab half-life increased with R allele number (13.2, 14.4 and 15.6 days for HH, HR and RR patients, respectively). It decreased with increasing platelet count in R carriers: from ≈20 days (RR) and ≈17 days (HR) at 150 × 109/L, respectively, to ≈13 days (both HR and RR) at 350 × 109/L. Moreover, a flow cytometry assay showed that infliximab and monomeric IgG1 bound efficiently to platelet FcγRIIA H and R allotypes, whereas panitumumab and IgG2 bound poorly to the latter. We propose that infliximab (and presumably any IgG1 antibody) elimination is partly due to an unappreciated mechanism dependent on binding to platelet FcγRIIA, which is probably tuned by its affinity for IgG2.


Assuntos
Doença de Crohn/tratamento farmacológico , Imunoglobulina G/genética , Infliximab/administração & dosagem , Receptores de IgG/genética , Adulto , Complexo Antígeno-Anticorpo/genética , Complexo Antígeno-Anticorpo/imunologia , Plaquetas/efeitos dos fármacos , Plaquetas/imunologia , Doença de Crohn/sangue , Doença de Crohn/genética , Doença de Crohn/imunologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/imunologia , Feminino , Citometria de Fluxo , Humanos , Imunoglobulina G/imunologia , Infliximab/farmacocinética , Masculino , Ativação Plaquetária/efeitos dos fármacos , Contagem de Plaquetas , Polimorfismo Genético/genética
2.
PLoS One ; 16(7): e0253977, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34214116

RESUMO

SARS-CoV-2 pandemic is causing high morbidity and mortality burden worldwide with unprecedented strain on health care systems. To investigate the time course of the antibody response in relation to the outcome we performed a study in hospitalized COVID-19 patients. As comparison we also investigated the time course of the antibody response in SARS-CoV-2 asymptomatic subjects. Study results show that patients produce a strong antibody response to SARS-CoV-2 with high correlation between different viral antigens (spike protein and nucleoprotein) and among antibody classes (IgA, IgG, and IgM and neutralizing antibodies). The antibody peak is reached by 3 weeks from hospital admission followed by a sharp decrease. No difference was observed in any parameter of the antibody classes, including neutralizing antibodies, between subjects who recovered or with fatal outcome. Only few asymptomatic subjects developed antibodies at detectable levels.


Assuntos
Anticorpos Neutralizantes/biossíntese , Anticorpos Antivirais/biossíntese , Infecções Assintomáticas , COVID-19/imunologia , SARS-CoV-2/imunologia , Idoso , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , COVID-19/mortalidade , Comorbidade , Feminino , Hospitalização , Humanos , Imunoglobulina A/biossíntese , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Imunoglobulina G/biossíntese , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/biossíntese , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Admissão do Paciente , Estudos Retrospectivos
3.
Curr Rheumatol Rep ; 23(8): 65, 2021 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-34218350

RESUMO

PURPOSE OF REVIEW: COVID-19 patients have a procoagulant state with a high prevalence of thrombotic events. The hypothesis of an involvement of antiphospholipid antibodies (aPL) has been suggested by several reports. Here, we reviewed 48 studies investigating aPL in COVID-19 patients. RECENT FINDINGS: Prevalence of Lupus Anticoagulant (LA) ranged from 35% to 92% in ICU patients. Anti-cardiolipin (aCL) IgG and IgM were found in up to 52% and up to 40% of patients respectively. Anti-ß2-glycoprotein I (aß2-GPI) IgG and IgM were found in up to 39% and up to 34% of patients respectively. Between 1% and 12% of patients had a triple positive aPL profile. There was a high prevalence of aß2-GPI and aCL IgA isotype. Two cohort studies found few persistent LA but more persistent solid phase assay aPL over time. aPL determination and their potential role is a real challenge for the treatment of this disease.


Assuntos
Anticorpos Antifosfolipídeos/imunologia , COVID-19/imunologia , Trombose/imunologia , Anticorpos Anticardiolipina/imunologia , Proteína C-Reativa/imunologia , COVID-19/sangue , COVID-19/complicações , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Fibrinogênio/metabolismo , Humanos , Imunoglobulina A/imunologia , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Inibidor de Coagulação do Lúpus/imunologia , SARS-CoV-2 , Índice de Gravidade de Doença , Trombose/sangue , Trombose/etiologia , beta 2-Glicoproteína I/imunologia
4.
PLoS One ; 16(7): e0251342, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34197468

RESUMO

Amperial™ is a novel assay platform that uses immobilized antigen in a conducting polymer gel followed by detection via electrochemical measurement of oxidation-reduction reaction between H2O2/Tetrametylbenzidine and peroxidase enzyme in a completed assay complex. A highly specific and sensitive assay was developed to quantify levels of IgG antibodies to SARS-CoV-2 in saliva. After establishing linearity and limit of detection we established a reference range of 5 standard deviations above the mean. There were no false positives in 667 consecutive saliva samples obtained prior to 2019. Saliva was obtained from 34 patients who had recovered from documented COVID-19 or had documented positive serologies. All of the patients with symptoms severe enough to seek medical attention had positive antibody tests and 88% overall had positive results. We obtained blinded paired saliva and plasma samples from 14 individuals. The plasma was analyzed using an EUA-FDA cleared ELISA kit and the saliva was analyzed by our Amperial™ assay. All 5 samples with negative plasma titers were negative in saliva testing. Eight of the 9 positive plasma samples were positive in saliva and 1 had borderline results. A CLIA validation was performed as a laboratory developed test in a high complexity laboratory. A quantitative non-invasive saliva based SARS-CoV-2 antibody test was developed and validated with sufficient specificity to be useful for population-based monitoring and monitoring of individuals following vaccination.


Assuntos
Anticorpos Antivirais/imunologia , Teste Sorológico para COVID-19/métodos , COVID-19/diagnóstico , Imunoglobulina G/imunologia , SARS-CoV-2/imunologia , Saliva/imunologia , Anticorpos Antivirais/análise , COVID-19/imunologia , COVID-19/virologia , Técnicas Eletroquímicas/métodos , Humanos , Imunoglobulina G/análise , Limite de Detecção , SARS-CoV-2/isolamento & purificação , Saliva/virologia
5.
Curr Rheumatol Rep ; 23(9): 72, 2021 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-34259944

RESUMO

PURPOSE OF THE REVIEW: Elevated levels of anti-phospholipid (aPL) antibodies are the most important criterion in the diagnosis of anti-phospholipid syndrome (APS) and are usually responsible for promoting the risk of thrombotic complications. Now, in the course of the global coronavirus disease 2019 (COVID-19) pandemic, measurable aPL antibodies have also been detected in a noticeable number of patients showing a variety ranging from studies with only isolated positive tests to cohorts with very high positivity. Thus, the question arises as to whether these two different clinical pictures may be linked. RECENT FINDINGS: The ambivalent results showed a frequent occurrence of the investigated aPL antibodies in COVID-19 patients to an individually varying degree. While some question a substantial correlation according to their results, a number of studies raise questions about the significance of a correlation of aPL antibodies in COVID-19 patients. Within the scope of this review, these have now been described and compared with each other. Ultimately, it is necessary to conduct further studies that specifically test aPL antibodies in a larger context in order to make subsequent important statements about the role of APS in COVID-19 and to further strengthen the significance of the described comparisons.


Assuntos
Anticorpos Antifosfolipídeos/imunologia , COVID-19/imunologia , Anticorpos Anticardiolipina/imunologia , Humanos , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Inibidor de Coagulação do Lúpus/imunologia , SARS-CoV-2 , beta 2-Glicoproteína I/imunologia
6.
PLoS One ; 16(7): e0254516, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34242377

RESUMO

BACKGROUND: Monitoring changes of seroprevalence over time is important at the beginning and during of COVID-19 outbreak to anticipate its dynamics and plan an adequate public health response. METHODS: We conducted a repeated cross-sectional investigation among asymptomatic outpatient subjects and covered 0.1% of total population of Northern Serbia (Autonomous Province of Vojvodina). Each participant was tested for anti-SARS-CoV-2 antibodies using an immunochromatographic qualitative test (point-of-care rapid test). In the last round of survey IgG antibodies targeting the S1 subunit of the spike protein and the nucleocapsid protein of SARS-CoV-2 virus were assessed. RESULTS: During the four rounds of survey (between the end of April and the end of September), anti-SARS-CoV-2 seropositivities based on immunochromatographic test results were 2.60% (95% CI 1.80-3.63), 3.93% (95% CI 2.85-5.28), 6.11% (95% CI 4.72-7.77) and 14.60% (95% 12.51-16.89), respectively. After adjusting with results obtained from the Line immunoassay test, the estimated overall seroprevalence increased to 16.67% (95% CI 14.45-19.08) corresponding to 322,033 infections in total by the end of September 2020 in Vojvodina's population. Throughout the course of the study, for every RT-PCR confirmed case of COVID-19, there were 39-87 additional infections in Vojvodina. No significant difference (p>0.05) in SARS-CoV-2 seropositivity regarding gender and between age subgroups was observed over the course of the survey. CONCLUSIONS: The population prevalence of SARS-CoV-2 antibodies implies much more widespread infection in Vojvodina than indicated by the number of confirmed cases. However, our results suggest that the population of Vojvodina has not reached a desirable level of protection from SARS-CoV-2 virus by the end of September 2020.


Assuntos
Anticorpos Antivirais/imunologia , Teste de Ácido Nucleico para COVID-19 , COVID-19 , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , SARS-CoV-2/imunologia , Adolescente , Adulto , Idoso , COVID-19/diagnóstico , COVID-19/epidemiologia , COVID-19/imunologia , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Prevalência , SARS-CoV-2/genética , Sérvia/epidemiologia , Estudos Soroepidemiológicos
7.
Pediatr Infect Dis J ; 40(8): e294-e299, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34250968

RESUMO

INTRODUCTION: Antibody response developed within 2-3 weeks after exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been shown to decrease over time; however, there is limited data about antibody levels at 6 months or later postinfection, particularly in children. MATERIALS AND METHOD: A prospective multicenter study was performed using 315 samples of 74 confirmed and 10 probable coronavirus disease 2019 pediatric cases. About 20% of these cases were classified as asymptomatic, 74% as mild/moderate and 6% as severe/critical. Patients were included if at least 2 samples were available. The antibody response was classified as either early-period or late-period (14 days-3 months and after 6 months, respectively) for IgG response whereas IgA response was tested on various time intervals, including as early as 4 days up to 3 months. Euroimmun Anti-SARS-CoV-2 IgG and IgA and Genscript SARS-CoV-2 Surrogate Virus Neutralization Kits were used for antibody detection. RESULTS: There was no difference between the early-period and late-period IgG positivity (P = 0.1). However, the median IgG levels were 11.98 in the early periods and 4.05 in the late periods, with a significance of P < 0.001. Although the decrease in IgG levels was significant in asymptomatic and mild/moderate cases (P < 0.008 and P < 0.001, respectively), the decrease in severe/critical cases was moderate (P = 0.285). The sensitivity of the IgG after 15 days was higher than 94%, and the sensitivity of IgA was 88% on days 8-15. CONCLUSION: SARS-CoV-2 IgG antibody levels decreased after 6 months. The decrease was moderate in severe/critical cases. Overall, 95.8% of the patients remained positive up to 9 months after infection. Although the IgA response may be useful early on, the IgG response is useful after 14 days.


Assuntos
Anticorpos Antivirais/biossíntese , COVID-19/imunologia , SARS-CoV-2/imunologia , Adolescente , Anticorpos Antivirais/imunologia , Formação de Anticorpos , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Imunoglobulina A , Imunoglobulina G/biossíntese , Imunoglobulina G/imunologia , Lactente , Estudos Longitudinais , Masculino , Estudos Prospectivos
8.
Int J Nanomedicine ; 16: 4739-4753, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34267520

RESUMO

Background: Serological tests detecting severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) are widely used in seroprevalence studies and evaluating the efficacy of the vaccination program. Some of the widely used serological testing techniques are enzyme-linked immune-sorbent assay (ELISA), chemiluminescence immunoassay (CLIA), and lateral flow immunoassay (LFIA). However, these tests are plagued with low sensitivity or specificity, time-consuming, labor-intensive, and expensive. We developed a serological test implementing flow-through dot-blot assay (FT-DBA) for SARS-CoV-2 specific IgG detection, which provides enhanced sensitivity and specificity while being quick to perform and easy to use. Methods: SARS-CoV-2 antigens were immobilized on nitrocellulose membrane to capture human IgG, which was then detected with anti-human IgG conjugated gold nanoparticle (hIgG-AuNP). A total of 181 samples were analyzed in-house. Within which 35 were further evaluated in US FDA-approved CLIA Elecsys SARS-CoV-2 assay. The positive panel consisted of RT-qPCR positive samples from patients with both <14 days and >14 days from the onset of clinical symptoms. The negative panel contained samples collected from the pre-pandemic era dengue patients and healthy donors during the pandemic. Moreover, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of FT-DBA were evaluated against RT-qPCR positive sera. However, the overall efficacies were assessed with sera that seroconverted against either nucleocapsid (NCP) or receptor-binding domain (RBD). Results: In-house ELISA selected a total of 81 true seropositive and 100 seronegative samples. The sensitivity of samples with <14 days using FT-DBA was 94.7%, increasing to 100% for samples >14 days. The overall detection sensitivity and specificity were 98.8% and 98%, respectively, whereas the overall PPV and NPV were 99.6% and 99%. Moreover, comparative analysis between in-house ELISA assays and FT-DBA revealed clinical agreement of Cohen's Kappa value of 0.944. The FT-DBA showed sensitivity and specificity of 100% when compared with commercial CLIA kits. Conclusion: The assay can confirm past SARS-CoV-2 infection with high accuracy within 2 minutes compared to commercial CLIA or in-house ELISA. It can help track SARS-CoV-2 disease progression, population screening, and vaccination response. The ease of use of the assay without requiring any instruments while being semi-quantitative provides the avenue of its implementation in remote areas around the globe, where conventional serodiagnosis is not feasible.


Assuntos
Ouro/química , Immunoblotting/métodos , Imunoglobulina G/análise , Nanopartículas Metálicas/química , Nucleocapsídeo/análise , SARS-CoV-2/isolamento & purificação , Adulto , Anticorpos Antivirais/sangue , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Masculino , Valor Preditivo dos Testes , SARS-CoV-2/imunologia , Sensibilidade e Especificidade , Estudos Soroepidemiológicos
9.
Signal Transduct Target Ther ; 6(1): 256, 2021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-34234102

RESUMO

We collected blood from coronavirus disease 2019 (COVID-19) convalescent individuals and investigated SARS-CoV-2-specific humoral and cellular immunity in these discharged patients. Follow-up analysis in a cohort of 171 patients at 4-11 months after the onset revealed high levels of IgG antibodies. A total of 78.1% (164/210) of the specimens tested positive for neutralizing antibody (NAb). SARS-CoV-2 antigen peptide pools-stimulated-IL-2 and -IFN-γ response can distinguish COVID-19 convalescent individuals from healthy donors. Interestingly, NAb survival was significantly affected by the antigen peptide pools-stimulated-IL-2 response, -IL-8 response, and -IFN-γ response. The antigen peptide pools-activated CD8+ T cell counts were correlated with NAb. The antigen peptide pools-activated natural killer (NK) cell counts in convalescent individuals were correlated with NAb and disease severity. Our data suggested that the development of NAb is associated with the activation of T cells and NK cells. Our work provides a basis for further analysis of the protective immunity to SARS-CoV-2 and for understanding the pathogenesis of COVID-19. It also has implications for the development of an effective vaccine for SARS-CoV-2 infection.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Convalescença , Citocinas/imunologia , Feminino , Humanos , Imunidade Celular , Imunidade Humoral , Imunoglobulina G/imunologia , Subpopulações de Linfócitos/imunologia , Masculino , Pessoa de Meia-Idade , Adulto Jovem
10.
Front Immunol ; 12: 680188, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34262564

RESUMO

A significant proportion of COVID-19 patients will progress to critical illness requiring invasive mechanical ventilation. This accentuates the need for a therapy that can reduce the severity of COVID-19. Clinical trials have shown the effectiveness of remdesivir in shortening recovery time and decreasing progression to respiratory failure and mechanical ventilation. However, some studies have highlighted its lack of efficacy in patients on high-flow oxygen and mechanical ventilation. This study uncovers some underlying immune response differences between responders and non-responders to remdesivir treatment. Immunological analyses revealed an upregulation of tissue repair factors BDNF, PDGF-BB and PIGF-1, as well as an increase in ratio of Th2-associated cytokine IL-4 to Th1-associated cytokine IFN-γ. Serological profiling of IgG subclasses corroborated this observation, with significantly higher magnitude of increase in Th2-associated IgG2 and IgG4 responses. These findings help to identify the mechanisms of immune regulation accompanying successful remdesivir treatment in severe COVID-19 patients.


Assuntos
Monofosfato de Adenosina/análogos & derivados , Alanina/análogos & derivados , Antivirais/uso terapêutico , COVID-19/tratamento farmacológico , Citocinas/sangue , Hospitalização , SARS-CoV-2/genética , Monofosfato de Adenosina/uso terapêutico , Adulto , Idoso , Alanina/uso terapêutico , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Becaplermina/sangue , Fator Neurotrófico Derivado do Encéfalo/sangue , COVID-19/sangue , COVID-19/imunologia , Estudos de Casos e Controles , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Masculino , Proteínas de Membrana/sangue , Pessoa de Meia-Idade , Estudos Prospectivos , Glicoproteína da Espícula de Coronavírus/imunologia , Resultado do Tratamento
11.
Sci Immunol ; 6(61)2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-34266981

RESUMO

Ongoing SARS-CoV-2 vaccine development is focused on identifying stable, cost-effective, and accessible candidates for global use, specifically in low and middle-income countries. Here, we report the efficacy of a rapidly scalable, novel yeast expressed SARS-CoV-2 specific receptor-binding domain (RBD) based vaccine in rhesus macaques. We formulated the RBD immunogen in alum, a licensed and an emerging alum adsorbed TLR-7/8 targeted, 3M-052-alum adjuvants. The RBD+3M-052-alum adjuvanted vaccine promoted better RBD binding and effector antibodies, higher CoV-2 neutralizing antibodies, improved Th1 biased CD4+T cell reactions, and increased CD8+ T cell responses when compared to the alum-alone adjuvanted vaccine. RBD+3M-052-alum induced a significant reduction of SARS-CoV-2 virus in respiratory tract upon challenge, accompanied by reduced lung inflammation when compared with unvaccinated controls. Anti-RBD antibody responses in vaccinated animals inversely correlated with viral load in nasal secretions and BAL. RBD+3M-052-alum blocked a post SARS-CoV-2 challenge increase in CD14+CD16++ intermediate blood monocytes, and Fractalkine, MCP-1, and TRAIL in the plasma. Decreased plasma analytes and intermediate monocyte frequencies correlated with reduced nasal and BAL viral loads. Lastly, RBD-specific plasma cells accumulated in the draining lymph nodes and not in the bone marrow, contrary to previous findings. Together, these data show that a yeast expressed, RBD-based vaccine+3M-052-alum provides robust immune responses and protection against SARS-CoV-2, making it a strong and scalable vaccine candidate.


Assuntos
Adjuvantes Imunológicos/administração & dosagem , Compostos de Alúmen/administração & dosagem , Vacinas contra COVID-19 , COVID-19/prevenção & controle , SARS-CoV-2 , Saccharomycetales/genética , Glicoproteína da Espícula de Coronavírus/genética , Administração por Inalação , Administração Intranasal , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , COVID-19/imunologia , COVID-19/patologia , COVID-19/virologia , Linhagem Celular , Citocinas/imunologia , Humanos , Imunoglobulina G/imunologia , Pulmão/patologia , Macaca mulatta , Masculino , Ligação Proteica , Domínios Proteicos , Glicoproteína da Espícula de Coronavírus/imunologia , Carga Viral
12.
Mikrochim Acta ; 188(8): 261, 2021 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-34278534

RESUMO

The ongoing global pandemic of SARS-CoV-2 has promoted to develop novel serological testing technologies since they can be effectively complementary to RT-PCR. Here, a new all-fiber Fresnel reflection microfluidic biosensor (FRMB) was constructed through combining all-fiber optical system, microfluidic chip, and multimode fiber bio-probe. The transmission of the incident light and the collection and transmission of Fresnel reflection light are achieved using a single-multi-mode fiber optic coupler (SMFC) without any other optical separation elements. This compact design greatly simplifies the whole system structure and improves light transmission efficiency, which makes it suitable for the label-free, sensitive, and easy-to-use point-of-care testing (POCT) of targets in nanoliter samples. Based on Fresnel reflection mechanism and immunoassay principle, both the SARS-CoV-2 IgM and IgG antibodies against the SARS-CoV-2 spike protein could be sensitively quantified in 7 min using the secondary antibodies-modified multimode fiber bio-probe. The FRMB performs in one-step, is accurate, label-free, and sensitive in situ/on-site detection of SARS-CoV-2 IgM or IgG in serum with simple dilution only. The limits of detection of SARS-CoV-2 IgM and SARS-CoV-2 IgG were 0.82 ng/mL and 0.45 ng/mL, respectively. Based on our proposed theory, the affinity constants of SARS-CoV-2 IgM or IgG antibody and their respective secondary antibodies were also determined. The FRMB can be readily extended as a universal platform for the label-free, rapid, and sensitive in situ/on-site measurement of other biomarkers and the investigation of biomolecular interaction.


Assuntos
Anticorpos Antivirais/sangue , Técnicas Biossensoriais/métodos , Teste Sorológico para COVID-19/métodos , COVID-19/diagnóstico , Técnicas Analíticas Microfluídicas/métodos , SARS-CoV-2/imunologia , Anticorpos Antivirais/imunologia , Humanos , Imunoensaio/métodos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Limite de Detecção , SARS-CoV-2/química , Sensibilidade e Especificidade , Glicoproteína da Espícula de Coronavírus/imunologia
13.
PLoS One ; 16(7): e0254367, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34242356

RESUMO

COVID-19 serological test must have high sensitivity as well as specificity to rule out cross-reactivity with common coronaviruses (HCoVs). We have developed a quantitative multiplex test, measuring antibodies against spike (S) proteins of SARS-CoV-2, SARS-CoV, MERS-CoV, and common human coronavirus strains (229E, NL63, OC43, HKU1), and nucleocapsid (N) protein of SARS-CoV viruses. Receptor binding domain of S protein of SARS-CoV-2 (S-RBD), and N protein, demonstrated sensitivity (94% and 92.5%, respectively) in COVID-19 patients (n = 53), with 98% specificity in non-COVID-19 respiratory-disease (n = 98), and healthy-controls (n = 129). Anti S-RBD and N antibodies appeared five to ten days post-onset of symptoms, peaking at approximately four weeks. The appearance of IgG and IgM coincided while IgG subtypes, IgG1 and IgG3 appeared soon after the total IgG; IgG2 and IgG4 remained undetectable. Several inflammatory cytokines/chemokines were found to be elevated in many COVID-19 patients (e.g., Eotaxin, Gro-α, CXCL-10 (IP-10), RANTES (CCL5), IL-2Rα, MCP-1, and SCGF-b); CXCL-10 was elevated in all. In contrast to antibody titers, levels of CXCL-10 decreased with the improvement in patient health suggesting it as a candidate for disease resolution. Importantly, anti-N antibodies appear before S-RBD and differentiate between vaccinated and infected people-current vaccines (and several in the pipeline) are S protein-based.


Assuntos
Anticorpos Antivirais , COVID-19 , Quimiocinas , Proteínas do Nucleocapsídeo de Coronavírus , Imunoglobulina G , Imunoglobulina M , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Adulto , Animais , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , COVID-19/sangue , COVID-19/imunologia , Quimiocinas/sangue , Quimiocinas/imunologia , Proteínas do Nucleocapsídeo de Coronavírus/sangue , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Macaca mulatta , Masculino , Pessoa de Meia-Idade , Fosfoproteínas/sangue , Fosfoproteínas/imunologia , Coelhos , SARS-CoV-2/imunologia , SARS-CoV-2/metabolismo , Glicoproteína da Espícula de Coronavírus/sangue , Glicoproteína da Espícula de Coronavírus/imunologia
14.
Sci Rep ; 11(1): 13780, 2021 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-34215811

RESUMO

Most patients infected with SARS-CoV-2 are asymptomatic or mildly symptomatic. However, the early and late antibody kinetics, and the association between antibody levels, clinical symptoms, and disease phase in these patients have not yet been fully defined. Confirmed SARS-CoV-2 patients and their household contacts were evaluated over a period four months. The evaluation procedure included symptom monitoring, viral load and serology analysis every ten days. A total of 1334 serum samples were collected from 135 patients and analyzed using three assays for IgG-N, IgG-S and IgM antibodies. Of the study participants, 97% were seropositive during the study, and two distinct clusters were identified. These clusters were significantly different in their inflammatory related symptoms. Peak IgG-S was 40.0 AU/ml for the non-inflammatory cluster and 71.5 AU/ml for the inflammatory cluster (P = 0.006), whereas IgG-N peaks were 4.3 and 5.87 (P = 0.023) respectively. Finally, a decision tree model was designed to predict the disease phase based on the serological titer levels, and had an overall accuracy of 80.7%. The specific profile of seroconversion and decay of serum antibodies can be used to predict the time-course from the acute infection.


Assuntos
Anticorpos Antivirais/imunologia , COVID-19/imunologia , SARS-CoV-2/imunologia , Adulto , Idoso , Anticorpos Antivirais/sangue , COVID-19/sangue , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Masculino , Pessoa de Meia-Idade , Carga Viral
15.
BMC Nephrol ; 22(1): 251, 2021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34229622

RESUMO

BACKGROUND: The ongoing coronavirus pandemic has major impacts on both patients and healthcare systems worldwide, thus creating new realities. Patients on maintenance dialysis listed for renal transplantation are a vulnerable subgroup with many comorbidities and recurring contacts with the healthcare system. Due to the COVID-19 pandemic transplant numbers have dropped considerably, further increasing waiting times in this high-risk population. On the other hand, knowledge of the severity of SARS-CoV-2 infection in immunocompromised patients, development and persistence of neutralising antibodies in such patients is just emerging. It is unclear how best to address the dilemma of postponing the life-saving transplantation. CASE PRESENTATION: We present a case report of a successful kidney transplantation only 65 days after the recipient was hospitalized for treatment of COVID-19 pneumonia. In a follow up of 9 months, we observed no signs of recurrent disease and transplant function is excellent. Monitoring SARS-CoV-2 antibody response demonstrates stable IgG levels. CONCLUSION: This reassuring case provides guidance to transplant centers how to proceed with kidney transplantation safely during the pandemic. Careful consideration of risks and benefits of the organ offer, full recovery from COVID-19 symptoms and the presence of a positive SARS-CoV-2 IgG antibody test, qualifies for kidney transplantation.


Assuntos
Anticorpos Antivirais/imunologia , COVID-19/imunologia , Falência Renal Crônica/cirurgia , Transplante de Rim , Idoso , COVID-19/complicações , Teste Sorológico para COVID-19 , Feminino , Rejeição de Enxerto/prevenção & controle , Humanos , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Imunossupressores/uso terapêutico , Falência Renal Crônica/complicações , Diálise Renal , SARS-CoV-2
16.
Mikrochim Acta ; 188(8): 262, 2021 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-34282508

RESUMO

COVID-19 is now a severe threat to global health. Facing this pandemic, we developed a space-encoding microfluidic biochip for high-throughput, rapid, sensitive, simultaneous quantitative detection of SARS-CoV-2 antigen proteins and IgG/IgM antibodies in serum. The proposed immunoassay biochip integrates the advantages of graphene oxide quantum dots (GOQDs) and microfluidic chip and is capable of conducting multiple SARS-CoV-2 antigens or IgG/IgM antibodies of 60 serum samples simultaneously with only 2 µL sample volume of each patient. Fluorescence intensity of antigens and IgG antibody detection at emission wavelength of ~680 nm was used to quantify the target concentration at excitation wavelength of 632 nm, and emission wavelength of ~519 nm was used during the detection of IgM antibodies at excitation wavelength of 488 nm. The method developed has a large linear quantification detection regime of 5 orders of magnitude, an ultralow detection limit of ~0.3 pg/mL under optimized conditions, and less than 10-min qualitative detection time. The proposed biosensing platform will not only greatly facilitate the rapid diagnosis of COVID-19 patients, but also provide a valuable screening approach for infected patients, medical therapy, and vaccine recipients.


Assuntos
Antígenos Virais/sangue , Imunoensaio , Imunoglobulina G/sangue , Imunoglobulina M/sangue , SARS-CoV-2/isolamento & purificação , Reações Antígeno-Anticorpo , Antígenos Virais/imunologia , Humanos , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Nanopartículas/química , Tamanho da Partícula , SARS-CoV-2/imunologia , Sensibilidade e Especificidade
17.
Cell Rep ; 36(2): 109391, 2021 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-34242574

RESUMO

The immunogenicity of the SARS-CoV-2 proteome is largely unknown, especially for non-structural proteins and accessory proteins. In this study, we collect 2,360 COVID-19 sera and 601 control sera. We analyze these sera on a protein microarray with 20 proteins of SARS-CoV-2, building an antibody response landscape for immunoglobulin (Ig)G and IgM. Non-structural proteins and accessory proteins NSP1, NSP7, NSP8, RdRp, ORF3b, and ORF9b elicit prevalent IgG responses. The IgG patterns and dynamics of non-structural/accessory proteins are different from those of the S and N proteins. The IgG responses against these six proteins are associated with disease severity and clinical outcome, and they decline sharply about 20 days after symptom onset. In non-survivors, a sharp decrease of IgG antibodies against S1 and N proteins before death is observed. The global antibody responses to non-structural/accessory proteins revealed here may facilitate a deeper understanding of SARS-CoV-2 immunology.


Assuntos
COVID-19/imunologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Proteínas não Estruturais Virais/imunologia , Proteínas Virais Reguladoras e Acessórias/imunologia , Adulto , Idoso , Anticorpos Antivirais/imunologia , Formação de Anticorpos , Humanos , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Masculino , Pessoa de Meia-Idade , Análise Serial de Proteínas
18.
Nat Commun ; 12(1): 3790, 2021 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-34145240

RESUMO

The receptor tyrosine kinase HER2 acts as oncogenic driver in numerous cancers. Usually, the gene is amplified, resulting in receptor overexpression, massively increased signaling and unchecked proliferation. However, tumors become frequently addicted to oncogenes and hence are druggable by targeted interventions. Here, we design an anti-HER2 biparatopic and tetravalent IgG fusion with a multimodal mechanism of action. The molecule first induces HER2 clustering into inactive complexes, evidenced by reduced mobility of surface HER2. However, in contrast to our earlier binders based on DARPins, clusters of HER2 are thereafter robustly internalized and quantitatively degraded. This multimodal mechanism of action is found only in few of the tetravalent constructs investigated, which must target specific epitopes on HER2 in a defined geometric arrangement. The inhibitory effect of our antibody as single agent surpasses the combination of trastuzumab and pertuzumab as well as its parental mAbs in vitro and it is effective in a xenograft model.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Antineoplásicos Imunológicos/uso terapêutico , Neoplasias da Mama/terapia , Receptor ErbB-2/antagonistas & inibidores , Receptor ErbB-2/imunologia , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais Humanizados/uso terapêutico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Desenho de Fármacos , Feminino , Células HeLa , Humanos , Imunoglobulina G/imunologia , Imunoterapia/métodos , Células MCF-7 , Camundongos , Camundongos SCID , Trastuzumab/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto
19.
Nat Commun ; 12(1): 3789, 2021 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-34145279

RESUMO

Influenza viruses are a major public health problem. Vaccines are the best available countermeasure to induce effective immunity against infection with seasonal influenza viruses; however, the breadth of antibody responses in infection versus vaccination is quite different. Here, we show that nasal infection controls two sequential processes to induce neutralizing IgG antibodies recognizing the hemagglutinin (HA) of heterotypic strains. The first is viral replication in the lung, which facilitates exposure of shared epitopes that are otherwise hidden from the immune system. The second process is the germinal center (GC) response, in particular, IL-4 derived from follicular helper T cells has an essential role in the expansion of rare GC-B cells recognizing the shared epitopes. Therefore, the combination of exposure of the shared epitopes and efficient proliferation of GC-B cells is critical for generating broadly-protective antibodies. These observations provide insight into mechanisms promoting broad protection from virus infection.


Assuntos
Anticorpos Antivirais/imunologia , Linfócitos B/imunologia , Anticorpos Amplamente Neutralizantes/imunologia , Hemaglutininas Virais/imunologia , Interleucina-4/imunologia , Infecções por Orthomyxoviridae/imunologia , Animais , Anticorpos Antivirais/sangue , Anticorpos Amplamente Neutralizantes/sangue , Epitopos/imunologia , Feminino , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H2N2/imunologia , Vírus da Influenza A Subtipo H3N2/imunologia , Vacinas contra Influenza/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transdução de Sinais/imunologia , Células T Auxiliares Foliculares/imunologia , Vacinação
20.
Science ; 372(6546): 1102-1105, 2021 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-34083490

RESUMO

Although antiviral antibodies generally confer protective functions, antibodies against dengue virus (DENV) are associated with enhanced disease susceptibility. Antibodies can mediate DENV infection of leukocytes via Fcγ receptors, likely contributing to dengue disease pathogenesis. To determine if this mechanism accounts for variable disease severity, we examined Fab and Fc structures of anti-DENV antibodies from patients before and after infection and with variable disease outcomes. Neither antibody titers nor neutralizing activity correlated with disease severity in DENV-infected populations. Rather, DENV infection induced a specific increase in immunoglobulin G1 (IgG1) afucosylation, and the levels of afucosylated IgG1 were predictive of dengue disease severity. Thus, the IgG1 fucosylation status represents a robust prognostic tool for dengue disease, highlighting the key role of the Fc glycan structure in dengue pathogenesis.


Assuntos
Anticorpos Antivirais/sangue , Anticorpos Antivirais/química , Vírus da Dengue/imunologia , Dengue/imunologia , Fucose/análise , Dengue Grave/imunologia , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Anticorpos Facilitadores , Criança , Coinfecção/imunologia , Dengue/fisiopatologia , Feminino , Humanos , Fragmentos Fc das Imunoglobulinas/química , Fragmentos Fc das Imunoglobulinas/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/química , Imunoglobulina G/imunologia , Masculino , Receptores de IgG/química , Receptores de IgG/imunologia , Dengue Grave/fisiopatologia , Índice de Gravidade de Doença , Infecção por Zika virus/imunologia
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