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1.
J Immunol ; 208(8): 1912-1923, 2022 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-35379745

RESUMO

The mechanism regulating the life span of short-lived plasma cells (SLPCs) remains poorly understood. Here we demonstrated that the EP4-mediated activation of AKT by PGE2 was required for the proper control of inositol-requiring transmembrane kinase endoribonuclease-1α (IRE1α) hyperactivation and hence the endoplasmic reticulum (ER) homeostasis in IgM-producing SLPCs. Disruption of the PGE2-EP4-AKT signaling pathway resulted in IRE1α-induced activation of JNK, leading to accelerated death of SLPCs. Consequently, Ptger4-deficient mice (C57BL/6) exhibited a markedly impaired IgM response to T-independent Ags and increased susceptibility to Streptococcus pneumoniae infection. This study reveals a highly selective impact of the PGE2-EP4 signal on the humoral immunity and provides a link between ER stress response and the life span of SLPCs.


Assuntos
Sobrevivência Celular , Dinoprostona , Estresse do Retículo Endoplasmático , Endorribonucleases , Plasmócitos , Animais , Sobrevivência Celular/imunologia , Dinoprostona/imunologia , Estresse do Retículo Endoplasmático/imunologia , Endorribonucleases/imunologia , Imunoglobulina M/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Plasmócitos/imunologia , Prostaglandinas/imunologia , Prostaglandinas E/imunologia , /imunologia , Proteínas Proto-Oncogênicas c-akt/imunologia
2.
Elife ; 112022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35289271

RESUMO

Preexisting antibodies to endemic coronaviruses (CoV) that cross-react with SARS-CoV-2 have the potential to influence the antibody response to COVID-19 vaccination and infection for better or worse. In this observational study of mucosal and systemic humoral immunity in acutely infected, convalescent, and vaccinated subjects, we tested for cross-reactivity against endemic CoV spike (S) protein at subdomain resolution. Elevated responses, particularly to the ß-CoV OC43, were observed in all natural infection cohorts tested and were correlated with the response to SARS-CoV-2. The kinetics of this response and isotypes involved suggest that infection boosts preexisting antibody lineages raised against prior endemic CoV exposure that cross-react. While further research is needed to discern whether this recalled response is desirable or detrimental, the boosted antibodies principally targeted the better-conserved S2 subdomain of the viral spike and were not associated with neutralization activity. In contrast, vaccination with a stabilized spike mRNA vaccine did not robustly boost cross-reactive antibodies, suggesting differing antigenicity and immunogenicity. In sum, this study provides evidence that antibodies targeting endemic CoV are robustly boosted in response to SARS-CoV-2 infection but not to vaccination with stabilized S, and that depending on conformation or other factors, the S2 subdomain of the spike protein triggers a rapidly recalled, IgG-dominated response that lacks neutralization activity.


Assuntos
Anticorpos Antivirais/imunologia , Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , Reações Cruzadas/imunologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Especificidade de Anticorpos/imunologia , Interações Hospedeiro-Patógeno/imunologia , Humanos , Imunoglobulina A/imunologia , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Testes de Neutralização , Vacinação
3.
Sci Rep ; 12(1): 3351, 2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35233014

RESUMO

Severe acute respiratory coronavirus 2 (SARS-CoV-2) has spread globally since its emergence in 2019. Most SARS-CoV-2 infections generate immune responses leading to rising levels of immunoglobulins (Ig) M, A and G which can be detected using diagnostic tests including enzyme-linked immunosorbent assays (ELISA). Whilst implying previous SARS-CoV-2 infection, the detection of Ig by ELISA does not guarantee the presence of neutralising antibodies (NAb) that can prevent the virus infecting cells. Plaque reduction neutralisation tests (PRNT) detect NAb, but are not amenable to mass testing as they take several days and require use of SARS-CoV-2 in high biocontainment laboratories. We evaluated the ability of IgG and IgM ELISAs targeting SARS-CoV-2 spike subunit 1 receptor binding domain (S1-RBD), and spike subunit 2 (S2) and nucleocapsid protein (NP), at predicting the presence and magnitude of NAb determined by PRNT. IgG S2 + NP ELISA was 96.8% [95% CI 83.8-99.9] sensitive and 88.9% [95% CI 51.8-99.7] specific at predicting the presence of NAbs (PRNT80 > 1:40). IgG and IgM S1-RBD ELISAs correlated with PRNT titre, with higher ELISA results increasing the likelihood of a robust neutralising response. The IgM S1-RBD assay can be used as a rapid, high throughput test to approximate the magnitude of NAb titre.


Assuntos
Anticorpos Antivirais/imunologia , COVID-19/imunologia , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Testes de Neutralização , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Idoso , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
4.
MMWR Morb Mortal Wkly Rep ; 71(10): 375-377, 2022 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-35271558

RESUMO

The diagnosis of dengue disease, caused by the dengue virus (DENV) (a flavivirus), often requires serologic testing during acute and early convalescent phases of the disease. Some symptoms of DENV infection, such as nonspecific fever, are similar to those caused by infection with SARS-CoV-2, the virus that causes COVID-19. In studies with few COVID-19 cases, positive DENV immunoglobulin M (IgM) results were reported with various serologic tests, indicating possible cross-reactivity in these tests for DENV and SARS-CoV-2 infections (1,2). DENV antibodies can cross-react with other flaviviruses, including Zika virus. To assess the potential cross-reactivity of SARS-CoV-2, DENV, and Zika virus IgM antibodies, serum specimens from 97 patients from Puerto Rico and 12 U.S.-based patients with confirmed COVID-19 were tested using the DENV Detect IgM Capture enzyme-linked immunosorbent assay (ELISA) (InBios International).* In addition, 122 serum specimens from patients with confirmed dengue and 121 from patients with confirmed Zika virus disease (all from Puerto Rico) were tested using the SARS-CoV-2 pan-Ig Spike Protein ELISA (CDC).† Results obtained for DENV, Zika virus IgM, and SARS-CoV-2 antibodies indicated 98% test specificity and minimal levels of cross-reactivity between the two flaviviruses and SARS-CoV-2. These findings indicate that diagnoses of dengue or Zika virus diseases with the serological assays described in this report are not affected by COVID-19, nor do dengue or Zika virus diseases interfere with the diagnosis of COVID-19.


Assuntos
Anticorpos Antivirais/sangue , Vírus da Dengue/imunologia , Imunoglobulina M/imunologia , SARS-CoV-2/imunologia , Testes Sorológicos , Zika virus/imunologia , COVID-19/diagnóstico , Reações Cruzadas/imunologia , Dengue/diagnóstico , Ensaio de Imunoadsorção Enzimática , Humanos , Porto Rico , Sensibilidade e Especificidade , Estados Unidos , Infecção por Zika virus/diagnóstico
5.
Nat Microbiol ; 7(3): 423-433, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35132197

RESUMO

Elucidating the dynamics of the neutralizing antibody (nAb) response in coronavirus disease 2019 (COVID-19) convalescents is crucial in controlling the pandemic and informing vaccination strategies. Here we measured nAb titres across 411 sequential plasma samples collected during 1-480 d after illness onset or laboratory confirmation (d.a.o.) from 214 COVID-19 convalescents, covering the clinical spectrum of disease and without additional exposure history after recovery or vaccination against SARS-CoV-2, using authentic SARS-CoV-2 microneutralization (MN) assays. Forty-eight samples were also tested for neutralizing activities against the circulating variants using pseudotyped neutralization assay. Results showed that anti-RBD IgG and MN titres peaked at ~120 d.a.o. and subsequently declined, with significantly reduced nAb responses found in 91.67% of COVID-19 convalescents (≥50% decrease in current MN titres compared with the paired peak MN titres). Despite this decline, majority of the COVID-19 convalescents maintained detectable anti-RBD IgG and MN titres at 400-480 d.a.o., with undetectable neutralizing activity found in 14.41% (16/111) of the mild and 50% (5/10) of the asymptomatic infections at 330-480 d.a.o. Persistent antibody-dependent immunity could provide protection against circulating variants after one year, despite significantly decreased neutralizing activities against Beta, Delta and Mu variants. In conclusion, these data show that despite a marked decline in neutralizing activity over time, nAb responses persist for up to 480 d in most convalescents of symptomatic COVID-19, whereas a high rate of undetectable nAb responses was found in convalescents from asymptomatic infections.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/imunologia , SARS-CoV-2/fisiologia , Adolescente , Adulto , Idoso , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Infecções Assintomáticas/epidemiologia , COVID-19/sangue , COVID-19/epidemiologia , COVID-19/virologia , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Masculino , Pessoa de Meia-Idade , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Adulto Jovem
6.
Proc Natl Acad Sci U S A ; 119(6)2022 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-35131852

RESUMO

Homeostasis of metabolism by hormone production is crucial for maintaining physiological integrity, as disbalance can cause severe metabolic disorders such as diabetes mellitus. Here, we show that antibody-deficient mice and immunodeficiency patients have subphysiological blood glucose concentrations. Restoring blood glucose physiology required total IgG injections and insulin-specific IgG antibodies detected in total IgG preparations and in the serum of healthy individuals. In addition to the insulin-neutralizing anti-insulin IgG, we identified two fractions of anti-insulin IgM in the serum of healthy individuals. These autoreactive IgM fractions differ in their affinity to insulin. Interestingly, the low-affinity IgM fraction (anti-insulin IgMlow) neutralizes insulin and leads to increased blood glucose, whereas the high-affinity IgM fraction (anti-insulin IgMhigh) protects insulin from neutralization by anti-insulin IgG, thereby preventing blood glucose dysregulation. To demonstrate that anti-insulin IgMhigh acts as a protector of insulin and counteracts insulin neutralization by anti-insulin IgG, we expressed the variable regions of a high-affinity anti-insulin antibody as IgG and IgM. Remarkably, the recombinant anti-insulin IgMhigh normalized insulin function and prevented IgG-mediated insulin neutralization. These results suggest that autoreactive antibodies recognizing insulin are key regulators of blood glucose and metabolism, as they control the concentration of insulin in the blood. Moreover, our data suggest that preventing autoimmune damage and maintaining physiological homeostasis requires adaptive tolerance mechanisms generating high-affinity autoreactive IgM antibodies during memory responses.


Assuntos
Autoanticorpos/imunologia , Glicemia/imunologia , Homeostase/imunologia , Insulina/imunologia , Animais , Afinidade de Anticorpos/imunologia , Doenças Autoimunes/imunologia , Feminino , Humanos , Tolerância Imunológica/imunologia , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Camundongos , Camundongos Endogâmicos C57BL
7.
Front Immunol ; 13: 829665, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35154152

RESUMO

Background: Understanding the long-term kinetic characteristics of SARS-CoV-2 antibodies and the impact of inactivated vaccines on SARS-CoV-2 antibodies in convalescent patients can provide information for developing and improving vaccination strategies in such populations. Methods: In this cohort, 402 convalescent patients who tested positive for SARS-CoV-2 by RT-PCR from 1 January to 22 June 2020 in Jiangsu, China, were enrolled. The epidemiological data included demographics, symptom onset, and vaccination history. Blood samples were collected and tested for antibody levels of specific IgG, IgM, RBD-IgG, S-IgG, and neutralizing antibodies using a the commercial magnetic chemiluminescence enzyme immunoassay. Results: The median follow-up time after symptom onset was 15.6 months (IQR, 14.6 to 15.8). Of the 402 convalescent patients, 44 (13.84%) received an inactivated vaccine against COVID-19. A total of 255 (80.19%) patients were IgG-positive and 65 (20.44%) were IgM-positive. The neutralizing antibody was 83.02%. Compared with non-vaccinated individuals, the IgG antibody levels in vaccinated people were higher (P=0.007). Similarly, antibody levels for RBD-IgG, S-IgG, and neutralizing antibodies were all highly increased in vaccinated individuals (P<0.05). IgG levels were significantly higher after vaccination than before vaccination in the same population. IgG levels in those who received 'single dose and ≥14d' were similar to those with two doses (P>0.05). Similar conclusions were drawn for RBD-IgG and the neutralizing antibody. Conclusion: 15.6 months after symptom onset, the majority of participants remained positive for serum-specific IgG, RBD-IgG, S-IgG, and neutralizing antibodies. For convalescent patients, a single dose of inactivated vaccine against COVID-19 can further boost antibody titres.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Vacinas contra COVID-19/imunologia , COVID-19/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Criança , China , Estudos de Coortes , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Masculino , Pessoa de Meia-Idade , SARS-CoV-2/imunologia , Vacinas de Produtos Inativados/imunologia , Adulto Jovem
8.
MAbs ; 14(1): 2031483, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35220888

RESUMO

Early humoral immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are dominated by IgM and IgA antibodies, which greatly contribute to virus neutralization at mucosal sites. Given the essential roles of IgM and IgA in the control and elimination of SARS-CoV-2 infection, the mucosal immunity could be exploited for therapeutic and prophylactic purposes. However, almost all neutralizing antibodies that are authorized for emergency use and under clinical development are IgG antibodies, and no vaccine has been developed to boost mucosal immunity for SARS-CoV-2 infection. In addition to IgM and IgA, bispecific antibodies (bsAbs) combine specificities of two antibodies in one molecule, representing an important alternative to monoclonal antibody cocktails. Here, we summarize the latest advances in studies on IgM, IgA and bsAbs against SARS-CoV-2. The current challenges and future directions in vaccine design and antibody-based therapeutics are also discussed.


Assuntos
Anticorpos Biespecíficos/imunologia , Anticorpos Antivirais/imunologia , COVID-19/tratamento farmacológico , Anticorpos Biespecíficos/uso terapêutico , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/uso terapêutico , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/uso terapêutico , Humanos , Imunoglobulina A/imunologia , Imunoglobulina A/uso terapêutico , Imunoglobulina M/imunologia , Imunoglobulina M/uso terapêutico , SARS-CoV-2
9.
Nat Commun ; 13(1): 446, 2022 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-35078982

RESUMO

Following acute infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) a significant proportion of individuals develop prolonged symptoms, a serious condition termed post-acute coronavirus disease 2019 (COVID-19) syndrome (PACS) or long COVID. Predictors of PACS are needed. In a prospective multicentric cohort study of 215 individuals, we study COVID-19 patients during primary infection and up to one year later, compared to healthy subjects. We discover an immunoglobulin (Ig) signature, based on total IgM and IgG3 levels, which - combined with age, history of asthma bronchiale, and five symptoms during primary infection - is able to predict the risk of PACS independently of timepoint of blood sampling. We validate the score in an independent cohort of 395 individuals with COVID-19. Our results highlight the benefit of measuring Igs for the early identification of patients at high risk for PACS, which facilitates the study of targeted treatment and pathomechanisms of PACS.


Assuntos
Anticorpos Antivirais/imunologia , COVID-19/complicações , COVID-19/imunologia , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , SARS-CoV-2/imunologia , Adulto , Idoso , Anticorpos Antivirais/sangue , COVID-19/sangue , COVID-19/diagnóstico , Estudos de Coortes , Tosse/sangue , Tosse/complicações , Tosse/imunologia , Dispneia/sangue , Dispneia/complicações , Dispneia/imunologia , Fadiga/sangue , Fadiga/complicações , Fadiga/imunologia , Feminino , Febre/sangue , Febre/complicações , Febre/imunologia , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Pessoa de Meia-Idade , Curva ROC , SARS-CoV-2/fisiologia
10.
J Immunol ; 208(3): 582-593, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34996836

RESUMO

Pemphigus vulgaris is an autoimmune blistering disease caused by IgG targeting desmoglein 3 (Dsg3), an adhesion molecule of keratinocytes. Anti-Dsg3 IgG production is prevented in healthy individuals, but it is unclear how Dsg3-specific B cells are regulated. To clarify the immunological condition regulating Dsg3-specific B cells, a pathogenic anti-Dsg3 Ig (AK23) knock-in mouse was generated. AK23 knock-in B cells developed normally without undergoing deletion or acquiring an anergic phenotype in vivo. The knock-in B cells showed Ca2+ influx upon IgM cross-linking and differentiated into AK23-IgG+ B cells after LPS and IL-4 stimulation in vitro that induced a pemphigus phenotype after adoptive transfer into Rag2 -/- mice. However, the knock-in mouse itself produced AK23-IgM but little IgG without blisters in vivo. Dsg3 immunization and skin inflammation caused AK23-IgG production and a pemphigus phenotype in vivo. Furthermore, Fcgr2b deficiency or haploinsufficiency spontaneously induced AK23-IgG production and a pemphigus phenotype with poor survival rates in AK23 knock-in mice. To assess Fcgr2b involvement in Ig class-switch efficiency, postswitch transcripts of B cells were quantified and significantly higher in Fcgr2b -/- and Fcgr2b +/- mice than wild-type mice in a gene dose-dependent manner. Finally, RNA sequencing revealed reduced expression of FCGR2B and FcγRIIB-related genes in patient B cells. These results indicated that Dsg3-specific B cells do not spontaneously perform pathogenic class switching in vivo, and pemphigus phenotype induction was prevented under normal conditions. Attenuated FcγRIIB signaling is also one of the drivers for pathogenic class switching and is consistent with immunological features identified from clinical samples. This study unveiled a characteristic immune state silencing autoreactive B cells in mice.


Assuntos
Desmogleína 3/genética , Switching de Imunoglobulina/imunologia , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Pênfigo/genética , Receptores de IgG/genética , Adulto , Idoso , Animais , Autoimunidade/imunologia , Linfócitos B/imunologia , Desmogleína 3/imunologia , Feminino , Técnicas de Introdução de Genes , Humanos , Imunoglobulina G/genética , Imunoglobulina M/genética , Queratinócitos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Pênfigo/imunologia , Pênfigo/patologia , Receptores de IgG/metabolismo
11.
PLoS One ; 17(1): e0262820, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35051239

RESUMO

BACKGROUND: Early and accurate detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is critical to prevent spread of the infection. Understanding of the antibody response to SARS-CoV-2 in patients with coronavirus disease 2019 (COVID-19) is insufficient, particularly in relation to those whose responses persist for more than 1 month after the onset of symptoms. We conducted a SARS-CoV-2 antibody test to identify factors affecting the serological response and to evaluate its diagnostic utility in patients with COVID-19. METHODS AND FINDING: We collected 1,048 residual serum samples from 396 patients with COVID-19 confirmed by real-time reverse transcription polymerase chain reaction (RT-PCR) for SARS-CoV-2. The samples had been used for routine admission tests in six healthcare institutions in Daegu. Antibody to SARS-CoV-2 was analyzed and the cutoff index (COI) was calculated for quantitative analysis. The patients' information was reviewed to evaluate the relationship between antibody positivity and clinical characteristics. The anti-SARS-CoV-2 antibody positivity rate was 85% and the average COI was 24·3. The positivity rate and COI increased with time elapsed since symptom onset. Anti-SARS-CoV-2 antibody persisted for at least 13 weeks after symptom onset at a high COI. There was a significant difference in anti-SARS-CoV-2 antibody positivity rate between patients with and without symptoms, but not according to sex or disease course. The descending COI pattern at weeks 1 to 5 after symptom onset was significantly more frequent in patients who died than in those who recovered. CONCLUSIONS: Anti-SARS-CoV-2 antibody persisted for at least 13 weeks at a high COI in patients with COVID-19. A decreasing COI pattern up to fifth week may be associated with a poor prognosis of COVID-19. As new treatments and vaccines are introduced, it is important to monitor continuously the usefulness of anti-SARS-CoV-2 antibody assays.


Assuntos
Anticorpos Antivirais/sangue , Teste Sorológico para COVID-19/métodos , COVID-19/sangue , COVID-19/epidemiologia , SARS-CoV-2/imunologia , Idoso , Anticorpos Antivirais/imunologia , COVID-19/diagnóstico , COVID-19/imunologia , Teste de Ácido Nucleico para COVID-19/métodos , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase em Tempo Real/métodos , República da Coreia/epidemiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , SARS-CoV-2/genética , Sensibilidade e Especificidade
12.
Immunohorizons ; 6(1): 47-63, 2022 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-35042773

RESUMO

The Fc receptor for IgM, FcMR, is unusual in that it is preferentially expressed by cells of the adaptive immune system. It is, moreover, the only constitutively expressed Fc receptor on human T cells. Efforts to decipher the normal functions of FcMR have been complicated by species-specific expression patterns in lymphocytes from mice (B cells) versus humans (B, NK, and T cells). In human cells, FcMR cell-surface expression has been reported to be low at baseline ex vivo, with one suggested contribution being ligand-induced internalization by serum IgM. Indeed, preincubation overnight in IgM-free culture medium is recommended for studies of FcMR because surface display is increased under these conditions. We investigated FcMR display on human lymphocytes in PBMCs and found that, surprisingly, cell-surface FcMR was unaffected by IgM abundance and was instead downregulated in high-cell density cultures by a yet undefined mechanism. We further found that ex vivo processing of whole blood decreased surface FcMR, supporting the idea that FcMR expression is likely to be greater on circulating lymphocytes than previously appreciated. Collectively, these findings prompt new predictions of where and when FcMR might be available for functional interactions in vivo.


Assuntos
Linfócitos B/citologia , Imunoglobulina M/imunologia , Receptores Fc/imunologia , Linfócitos T/citologia , Linfócitos B/imunologia , Contagem de Células , Humanos , Leucócitos Mononucleares/metabolismo , Linfopoese/imunologia , Proteínas de Membrana/imunologia , Receptores Fc/biossíntese , Linfócitos T/imunologia
13.
Viruses ; 14(1)2022 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-35062329

RESUMO

Porcine epidemic diarrhea virus (PEDV) causes devastating enteric disease that inflicts huge economic damage on the swine industry worldwide. A safe and highly effective PEDV vaccine that contains only the virus-neutralizing epitopes (not enhancing epitope), as well as a ready-to-use PEDV neutralizing antibody for the passive immunization of PEDV vulnerable piglets (during the first week of life) are needed, particularly for PEDV-endemic farms. In this study, we generated monoclonal antibodies (mAbs) to the recombinant S1 domain of PEDV spike (S) protein and tested their PEDV neutralizing activity by CPE-reduction assay. The mAb secreted by one hybrodoma clone (A3), that also bound to the native S1 counterpart from PEDV-infected cells (tested by combined co-immunoprecipitation and Western blotting), neutralized PEDV infectivity. Epitope of the neutralizing mAb (mAbA3) locates in the S1A subdomain of the spike protein, as identified by phage mimotope search and multiple sequence alignment, and peptide binding-ELISA. The newly identified epitope is shared by PEDV G1 and G2 strains and other alphacoronaviruses. In summary, mAbA3 may be useful as a ready-to-use antibody for passive immunization of PEDV-susceptible piglets, while the novel neutralizing epitope, together with other, previously known protective epitopes, have potential as an immunogenic cocktail for a safe, next-generation PEDV vaccine.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Epitopos/imunologia , Imunoglobulina M/imunologia , Vírus da Diarreia Epidêmica Suína/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Animais , Chlorocebus aethiops , Ensaio de Imunoadsorção Enzimática , Feminino , Células HeLa , Humanos , Imunização Passiva , Camundongos , Camundongos Endogâmicos BALB C , Testes de Neutralização , Alinhamento de Sequência , Glicoproteína da Espícula de Coronavírus/genética , Suínos , Doenças dos Suínos/imunologia , Células Vero
14.
PLoS One ; 17(1): e0262162, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34982806

RESUMO

Analysis of convalescent plasma derived from individuals has shown that IgG3 has the most important role in binding to SARS-CoV-2 antigens; however, this has not yet been confirmed in large studies, and the link between binding and neutralization has not been confirmed. By analyzing plasma pools consisting of 247-567 individual convalescent donors, we demonstrated the binding of IgG3 and IgM to Spike-1 protein and the receptor-binding domain correlates strongly with viral neutralization in vitro. Furthermore, despite accounting for only approximately 12% of total immunoglobulin mass, collectively IgG3 and IgM account for approximately 80% of the total neutralization. This may have important implications for the development of potent therapies for COVID-19, as it indicates that hyperimmune globulins or convalescent plasma donations with high IgG3 concentrations may be a highly efficacious therapy.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/sangue , COVID-19/imunologia , Convalescença , Imunoglobulina G/imunologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Chlorocebus aethiops , Ensaio de Imunoadsorção Enzimática , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , SARS-CoV-2/fisiologia , Células Vero
15.
PLoS One ; 17(1): e0262312, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34995319

RESUMO

Yellow fever is endemic in Ghana and outbreaks occur periodically. The prodromal signs due to Yellow Fever Virus (YFV) infection are non-specific, making clinical signs unreliable as the sole criteria for diagnosis. Accurate laboratory confirmation of suspected yellow fever cases is therefore vital in surveillance programs. Reporting of ELISA IgM testing results by laboratories can delay due to late arrival of samples from the collection sites as well as limited availability of ELISA kits. In this study, the diagnostic performance characteristics of a rapid immunochromatographic Standard Q Yellow Fever IgM test kit (SD Biosensor) was evaluated for the rapid diagnosis of Yellow Fever infection in Ghana. A panel of 275 sera, comprising 81 confirmed YFV positives and 194 negatives were re-tested in this study using the Standard Q Yellow Fever IgM test kit. Using the CDC/WHO Yellow Fever IgM capture ELISA as a benchmark, the sensitivity, specificity and accuracy of the Standard Q Yellow Fever test kit were 96.3%, 97.9% and 97.5%, respectively. The false positivity rate was 5.1% and there was no cross-reactivity when the Standard Q Yellow Fever test kit was tested against dengue, malaria and hepatitis B and C positive samples. In addition, inter-reader variability and invalid rate were both zero. The results indicate that the diagnostic performance of the Standard Q Yellow Fever IgM test kit on serum or plasma is comparable to the serum IgM detection by ELISA and can be used as a point of care rapid diagnostic test kit for YFV infection in endemic areas.


Assuntos
Técnicas Biossensoriais/instrumentação , Cromatografia de Afinidade/instrumentação , Imunoglobulina M/imunologia , Kit de Reagentes para Diagnóstico , Febre Amarela/diagnóstico , Vírus da Febre Amarela/imunologia , Técnicas Biossensoriais/economia , Cromatografia de Afinidade/economia , Desenho de Equipamento , Humanos , Imunoglobulina M/sangue , Limite de Detecção , Kit de Reagentes para Diagnóstico/economia , Fatores de Tempo , Febre Amarela/sangue , Febre Amarela/imunologia , Vírus da Febre Amarela/isolamento & purificação
16.
PLoS One ; 17(1): e0262868, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35061843

RESUMO

A serological COVID-19 Multiplex Assay was developed and validated using serum samples from convalescent patients and those collected prior to the 2020 pandemic. After initial testing of multiple potential antigens, the SARS-CoV-2 nucleocapsid protein (NP) and receptor-binding domain (RBD) of the spike protein were selected for the human COVID-19 Multiplex Assay. A comparison of synthesized and mammalian expressed RBD proteins revealed clear advantages of mammalian expression. Antibodies directed against NP strongly correlated with SARS-CoV-2 virus neutralization assay titers (rsp = 0.726), while anti-RBD correlation was moderate (rsp = 0.436). Pan-Ig, IgG, IgA, and IgM against NP and RBD antigens were evaluated on the validation sample sets. Detection of NP and RBD specific IgG and IgA had outstanding performance (AUC > 0.90) for distinguishing patients from controls, but the dynamic range of the IgG assay was substantially greater. The COVID-19 Multiplex Assay was utilized to identify seroprevalence to SARS-CoV-2 in people living in a low-incidence community in Ithaca, NY. Samples were taken from a cohort of healthy volunteers (n = 332) in early June 2020. Only two volunteers had a positive result on a COVID-19 PCR test performed prior to serum sampling. Serological testing revealed an exposure rate of at least 1.2% (NP) or as high as 5.7% (RBD), higher than the measured incidence rate of 0.16% in the county at that time. This highly sensitive and quantitative assay can be used for monitoring community exposure rates and duration of immune response following both infection and vaccination.


Assuntos
Anticorpos Antivirais/química , Teste Sorológico para COVID-19/métodos , COVID-19/diagnóstico , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/sangue , COVID-19/epidemiologia , Teste Sorológico para COVID-19/normas , Proteínas do Nucleocapsídeo de Coronavírus/química , Monitoramento Epidemiológico , Feminino , Humanos , Imunoglobulina A/química , Imunoglobulina A/imunologia , Imunoglobulina G/química , Imunoglobulina G/imunologia , Imunoglobulina M/química , Imunoglobulina M/imunologia , Masculino , Pessoa de Meia-Idade , New York/epidemiologia , Fosfoproteínas/química , Fosfoproteínas/imunologia , Domínios e Motivos de Interação entre Proteínas , Proteínas Recombinantes/química , Proteínas Recombinantes/imunologia , SARS-CoV-2/classificação , Sensibilidade e Especificidade , Glicoproteína da Espícula de Coronavírus/química
17.
Nat Commun ; 13(1): 320, 2022 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-35042863

RESUMO

Pregnant women represent a high-risk population for severe/critical COVID-19 and mortality. However, the maternal-fetal immune responses initiated by SARS-CoV-2 infection, and whether this virus is detectable in the placenta, are still under investigation. Here we show that SARS-CoV-2 infection during pregnancy primarily induces unique inflammatory responses at the maternal-fetal interface, which are largely governed by maternal T cells and fetal stromal cells. SARS-CoV-2 infection during pregnancy is also associated with humoral and cellular immune responses in the maternal blood, as well as with a mild cytokine response in the neonatal circulation (i.e., umbilical cord blood), without compromising the T-cell repertoire or initiating IgM responses. Importantly, SARS-CoV-2 is not detected in the placental tissues, nor is the sterility of the placenta compromised by maternal viral infection. This study provides insight into the maternal-fetal immune responses triggered by SARS-CoV-2 and emphasizes the rarity of placental infection.


Assuntos
COVID-19/imunologia , Imunidade/imunologia , Transmissão Vertical de Doenças Infecciosas , Placenta/imunologia , Complicações Infecciosas na Gravidez/imunologia , SARS-CoV-2/imunologia , Adulto , COVID-19/sangue , COVID-19/virologia , Citocinas/sangue , Citocinas/imunologia , Citocinas/metabolismo , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Recém-Nascido , Placenta/virologia , Gravidez , Complicações Infecciosas na Gravidez/sangue , Complicações Infecciosas na Gravidez/virologia , RNA Viral/genética , RNA Viral/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , SARS-CoV-2/genética , SARS-CoV-2/fisiologia , Adulto Jovem
18.
Int Immunol ; 34(1): 35-43, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34673932

RESUMO

Marginal zone B cells (MZBs) represent a unique B-cell sub-population that rapidly differentiate into IgM-secreting plasma cells in response to T-independent (T-I) antigen. Sphingosine 1-phosphate (S1P) promotes MZB localization to the marginal zone. However, intracellular molecules involved in MZB localization and migration remain largely unknown. Here, we show that MZBs lacking the glia maturation factor-γ (GMFG) are impaired in chemotaxis toward S1P under both in vitro and in vivo conditions, suggesting that GMFG is an effector downstream of S1P receptors. GMFG undergoes serine phosphorylation upon S1P stimulation and is required for S1P-induced desensitization of S1P receptor 1 (S1PR1). Compared with wild-type mice, Gmfg-/- mice produce elevated levels of 4-hydroxy-3-nitrophenyl-acetyl (NP)-specific IgM against a T-I type II antigen, NP-Ficoll, accompanied by dysregulated MZB localization. These results identify GMFG as a regulator of S1P-induced MZB chemotaxis and reveal a role for MZB localization in the marginal zone for optimal IgM production against a T-I antigen.


Assuntos
Antígenos T-Independentes/imunologia , Linfócitos B/imunologia , Quimiotaxia/imunologia , Fator de Maturação da Glia/imunologia , Imunoglobulina M/imunologia , Receptores de Esfingosina-1-Fosfato/imunologia , Animais , Fator de Maturação da Glia/deficiência , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
19.
J Mol Biol ; 434(2): 167332, 2022 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-34717971

RESUMO

Extensive glycosylation of viral glycoproteins is a key feature of the antigenic surface of viruses and yet glycan processing can also be influenced by the manner of their recombinant production. The low yields of the soluble form of the trimeric spike (S) glycoprotein from SARS-CoV-2 has prompted advances in protein engineering that have greatly enhanced the stability and yields of the glycoprotein. The latest expression-enhanced version of the spike incorporates six proline substitutions to stabilize the prefusion conformation (termed SARS-CoV-2 S HexaPro). Although the substitutions greatly enhanced expression whilst not compromising protein structure, the influence of these substitutions on glycan processing has not been explored. Here, we show that the site-specific N-linked glycosylation of the expression-enhanced HexaPro resembles that of an earlier version containing two proline substitutions (2P), and that both capture features of native viral glycosylation. However, there are site-specific differences in glycosylation of HexaPro when compared to 2P. Despite these discrepancies, analysis of the serological reactivity of clinical samples from infected individuals confirmed that both HexaPro and 2P protein are equally able to detect IgG, IgA, and IgM responses in all sera analysed. Moreover, we extend this observation to include an analysis of glycan engineered S protein, whereby all N-linked glycans were converted to oligomannose-type and conclude that serological activity is not impacted by large scale changes in glycosylation. These observations suggest that variations in glycan processing will not impact the serological assessments currently being performed across the globe.


Assuntos
Anticorpos Antivirais/imunologia , COVID-19/imunologia , Mutação de Sentido Incorreto/imunologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Anticorpos Antivirais/sangue , Sítios de Ligação/genética , COVID-19/virologia , Glicosilação , Humanos , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Manose/metabolismo , Mutação de Sentido Incorreto/genética , Oligossacarídeos/metabolismo , Polissacarídeos/metabolismo , Prolina/genética , Prolina/imunologia , Prolina/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , SARS-CoV-2/metabolismo , SARS-CoV-2/fisiologia , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/metabolismo
20.
Br J Haematol ; 196(3): 548-558, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34649298

RESUMO

Patients affected by lymphoid malignancies (LM) are frequently immune-compromised, suffering increased mortality from COVID-19. This prospective study evaluated serological and T-cell responses after complete mRNA vaccination in 263 patients affected by chronic lymphocytic leukaemia, B- and T-cell lymphomas and multiple myeloma. Results were compared with those of 167 healthy subjects matched for age and sex. Overall, patient seroconversion rate was 64·6%: serological response was lower in those receiving anti-cancer treatments in the 12 months before vaccination: 55% vs 81·9% (P < 0·001). Anti-CD20 antibody plus chemotherapy treatment was associated with the lowest seroconversion rate: 17·6% vs. 71·2% (P < 0·001). In the multivariate analysis conducted in the subgroup of patients on active treatment, independent predictors for seroconversion were: anti-CD20 treatment (P < 0·001), aggressive B-cell lymphoma diagnosis (P = 0·002), and immunoglobulin M levels <40 mg/dl (P = 0·030). The T-cell response was evaluated in 99 patients and detected in 85 of them (86%). Of note, 74% of seronegative patients had a T-cell response, but both cellular and humoral responses were absent in 13·1% of cases. Our findings raise some concerns about the protection that patients with LM, particularly those receiving anti-CD20 antibodies, may gain from vaccination. These patients should strictly maintain all the protective measures.


Assuntos
/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , COVID-19 , Neoplasias Hematológicas , Imunidade Celular/efeitos dos fármacos , Transtornos Linfoproliferativos , SARS-CoV-2/imunologia , Linfócitos T/imunologia , /imunologia , Idoso , Anticorpos Antivirais/imunologia , COVID-19/imunologia , COVID-19/prevenção & controle , Feminino , Neoplasias Hematológicas/tratamento farmacológico , Neoplasias Hematológicas/imunologia , Humanos , Imunoglobulina M/imunologia , Transtornos Linfoproliferativos/tratamento farmacológico , Transtornos Linfoproliferativos/imunologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Soroconversão
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