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1.
Front Immunol ; 12: 677025, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34504487

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is a global crisis; however, our current understanding of the host immune response to SARS-CoV-2 infection remains limited. Herein, we performed RNA sequencing using peripheral blood from acute and convalescent patients and interrogated the dynamic changes of adaptive immune response to SARS-CoV-2 infection over time. Our results revealed numerous alterations in these cohorts in terms of gene expression profiles and the features of immune repertoire. Moreover, a machine learning method was developed and resulted in the identification of five independent biomarkers and a collection of biomarkers that could accurately differentiate and predict the development of COVID-19. Interestingly, the increased expression of one of these biomarkers, UCHL1, a molecule related to nervous system damage, was associated with the clustering of severe symptoms. Importantly, analyses on immune repertoire metrics revealed the distinct kinetics of T-cell and B-cell responses to SARS-CoV-2 infection, with B-cell response plateaued in the acute phase and declined thereafter, whereas T-cell response can be maintained for up to 6 months post-infection onset and T-cell clonality was positively correlated with the serum level of anti-SARS-CoV-2 IgG. Together, the significantly altered genes or biomarkers, as well as the abnormally high levels of B-cell response in acute infection, may contribute to the pathogenesis of COVID-19 through mediating inflammation and immune responses, whereas prolonged T-cell response in the convalescents might help these patients in preventing reinfection. Thus, our findings could provide insight into the underlying molecular mechanism of host immune response to COVID-19 and facilitate the development of novel therapeutic strategies and effective vaccines.


Assuntos
COVID-19/genética , COVID-19/imunologia , Leucócitos Mononucleares/química , Transcriptoma , Adulto , Idoso , Anticorpos Antivirais/sangue , Linfócitos B/imunologia , Biomarcadores/sangue , COVID-19/sangue , COVID-19/virologia , China , Estudos de Coortes , Feminino , Humanos , Leucócitos Mononucleares/imunologia , Aprendizado de Máquina , Masculino , Pessoa de Meia-Idade , SARS-CoV-2/fisiologia , Análise de Sequência de RNA , Linfócitos T/imunologia , Ubiquitina Tiolesterase/genética , Ubiquitina Tiolesterase/imunologia
2.
Nat Commun ; 12(1): 5215, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34471122

RESUMO

Achieving sufficient worldwide vaccination coverage against SARS-CoV-2 will require additional approaches to currently approved viral vector and mRNA vaccines. Subunit vaccines may have distinct advantages when immunizing vulnerable individuals, children and pregnant women. Here, we present a new generation of subunit vaccines targeting viral antigens to CD40-expressing antigen-presenting cells. We demonstrate that targeting the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein to CD40 (αCD40.RBD) induces significant levels of specific T and B cells, with long-term memory phenotypes, in a humanized mouse model. Additionally, we demonstrate that a single dose of the αCD40.RBD vaccine, injected without adjuvant, is sufficient to boost a rapid increase in neutralizing antibodies in convalescent non-human primates (NHPs) exposed six months previously to SARS-CoV-2. Vaccine-elicited antibodies cross-neutralize different SARS-CoV-2 variants, including D614G, B1.1.7 and to a lesser extent B1.351. Such vaccination significantly improves protection against a new high-dose virulent challenge versus that in non-vaccinated convalescent animals.


Assuntos
Antígenos CD40/imunologia , Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Animais , Células Apresentadoras de Antígenos/imunologia , Linfócitos B/imunologia , Convalescença , Humanos , Macaca , Camundongos , Mutação , Domínios Proteicos , Reinfecção/prevenção & controle , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Linfócitos T/imunologia , Vacinação , Vacinas de Subunidades/imunologia
3.
Nat Commun ; 12(1): 4813, 2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34376664

RESUMO

Differences in immune responses to viruses and autoimmune diseases such as systemic lupus erythematosus (SLE) can show sexual dimorphism. Age-associated B cells (ABC) are a population of CD11c+T-bet+ B cells critical for antiviral responses and autoimmune disorders. Absence of DEF6 and SWAP-70, two homologous guanine exchange factors, in double-knock-out (DKO) mice leads to a lupus-like syndrome in females marked by accumulation of ABCs. Here we demonstrate that DKO ABCs show sex-specific differences in cell number, upregulation of an ISG signature, and further differentiation. DKO ABCs undergo oligoclonal expansion and differentiate into both CD11c+ and CD11c- effector B cell populations with pathogenic and pro-inflammatory function as demonstrated by BCR sequencing and fate-mapping experiments. Tlr7 duplication in DKO males overrides the sex-bias and further augments the dissemination and pathogenicity of ABCs, resulting in severe pulmonary inflammation and early mortality. Thus, sexual dimorphism shapes the expansion, function and differentiation of ABCs that accompanies TLR7-driven immunopathogenesis.


Assuntos
Envelhecimento/imunologia , Linfócitos B/imunologia , Diferenciação Celular/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Fatores Etários , Envelhecimento/genética , Animais , Linfócitos B/citologia , Linfócitos B/metabolismo , Antígeno CD11c/imunologia , Antígeno CD11c/metabolismo , Diferenciação Celular/genética , Células Cultivadas , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/imunologia , Proteínas de Ligação a DNA/metabolismo , Feminino , Fatores de Troca do Nucleotídeo Guanina/genética , Fatores de Troca do Nucleotídeo Guanina/imunologia , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Estimativa de Kaplan-Meier , Lúpus Eritematoso Sistêmico/genética , Lúpus Eritematoso Sistêmico/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Antígenos de Histocompatibilidade Menor/genética , Antígenos de Histocompatibilidade Menor/imunologia , Antígenos de Histocompatibilidade Menor/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/imunologia , Proteínas Nucleares/metabolismo , Fatores Sexuais , Proteínas com Domínio T/imunologia , Proteínas com Domínio T/metabolismo
4.
J Immunol ; 207(5): 1401-1410, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34380646

RESUMO

PI3Kδ is critical in generating humoral and regulatory immune responses. In this study, we determined the impact of PI3Kδ in immunity to Trypanosoma congolense, an African trypanosome that can manipulate and evade Ab responses critical for protection. Upon infection with T. congolense, PI3KδD910A mice lacking PI3Kδ activity paradoxically show a transient enhancement in early control of parasitemia, associated with impaired production of regulatory IL-10 by B cells in the peritoneum. C57BL/6 wild-type (WT) mice treated with the PI3Kδ inhibitor (PI3Kδi) Idelalisib showed a similar transient decrease in parasitemia associated with reduced IL-10. Strikingly, however, we find that PI3KδD910A mice were ultimately unable to control this infection, resulting in uncontrolled parasitemia and death within 2 wk. Assessment of humoral responses revealed delayed B cell activation, impaired germinal center responses, and compromised Ab responses to differing degrees in PI3KδD910A and PI3Kδi-treated mice. To test the role of Abs, we administered serum from WT mice to PI3KδD910A mice and found that lethality was prevented by postinfection serum. Interestingly, serum from naive WT mice provided partial protection to PI3KδD910A mutants, indicating an additional role for natural Abs. Together our findings suggest that although PI3Kδ drives immune regulatory responses that antagonize early control of parasite growth in the peritoneum, it is also required for generation of Abs that are critical for protection from systemic trypanosome infection. The essential role of PI3Kδ for host survival of African trypanosome infection contrasts with findings for other pathogens such as Leishmania, underlining the critical importance of PI3Kδ-dependent humoral immunity in this disease.


Assuntos
Linfócitos B/imunologia , Classe I de Fosfatidilinositol 3-Quinases/metabolismo , Trypanosoma congolense/fisiologia , Tripanossomíase Africana/imunologia , Animais , Classe I de Fosfatidilinositol 3-Quinases/genética , Imunidade Humoral , Imunomodulação , Interleucina-10/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Parasitemia
5.
J Immunol ; 207(5): 1478-1492, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34389622

RESUMO

Stable, long-term culture of primary B lymphocytes has many potential scientific and medical applications, but remains an elusive feat. A major obstacle to long-term culture is that in vitro mitogens quickly drive B cells to differentiate into short-lived plasma cells (PCs). PC differentiation is governed by opposing teams of transcription factors: Pax5, Bach2, and Bcl6 suppress PC commitment, whereas IFN regulatory factor 4 and Blimp1 promote it. To determine whether transcriptional programming could prolong B cell culture by blocking PC commitment, we generated mouse primary B cells harboring gain- or loss-of-function in the key transcription factors, continuously stimulated these cells with CD154 and IL-21, and determined growth potential and phenotypes in vitro. We found that transgenic expression of Bach2 prohibits PC commitment and endows B cells with extraordinary growth potential in response to external proliferation and survival cues. Long-term Bach2-transgenic B cell lines have genetically stable BCRs [i.e., do not acquire V(D)J mutations], express high levels of MHC class II and molecules for costimulation of T cells, and transduce intracellular signals when incubated with BCR ligands. Silencing the Bach2 transgene in an established transgenic cell line causes the cells to secrete large quantities of Ig. This system has potential applications in mAb production, BCR signaling studies, Ag presentation to T cells, and ex vivo clonal expansion for adoptive cell transfer. Additionally, our results provide insight into molecular control over activated B cell fate and suggest that forced Bach2 expression in vivo may augment germinal center B cell or memory B cell differentiation at the expense of PC commitment.


Assuntos
Linfócitos B/imunologia , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Centro Germinativo/imunologia , Animais , Fatores de Transcrição de Zíper de Leucina Básica/genética , Diferenciação Celular , Linhagem da Célula , Células Cultivadas , Regulação da Expressão Gênica , Memória Imunológica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mutação/genética , Fator de Transcrição PAX5/genética , Fator de Transcrição PAX5/metabolismo , Cultura Primária de Células , Proteínas Proto-Oncogênicas c-bcl-6/genética , Proteínas Proto-Oncogênicas c-bcl-6/metabolismo , Receptores de Antígenos de Linfócitos B/genética , Receptores de Antígenos de Linfócitos B/metabolismo
6.
Int J Mol Sci ; 22(16)2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34445084

RESUMO

Atherosclerosis is the major cause of the development of cardiovascular disease, which, in turn, is one of the leading causes of mortality worldwide. From the point of view of pathogenesis, atherosclerosis is an extremely complex disease. A huge variety of processes, such as violation of mitophagy, oxidative stress, damage to the endothelium, and others, are involved in atherogenesis; however, the main components of atherogenesis are considered to be inflammation and alterations of lipid metabolism. In this review, we want to focus on inflammation, and more specifically on the cellular elements of adaptive immunity, T and B cells. It is known that various T cells are widely represented directly in atherosclerotic plaques, while B cells can be found, for example, in the adventitia layer. Of course, such widespread and well-studied cells have attracted attention as potential therapeutic targets for the treatment of atherosclerosis. Various approaches have been developed and tested for their efficacy.


Assuntos
Aterosclerose/imunologia , Linfócitos B/imunologia , Imunidade , Linfócitos T/imunologia , Imunidade Adaptativa , Animais , Aterosclerose/patologia , Linfócitos B/patologia , Humanos , Imunidade Celular , Inflamação/imunologia , Inflamação/patologia , Linfócitos T/patologia
7.
Cells ; 10(8)2021 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-34440612

RESUMO

Assessment of humoral immunity to SARS-CoV-2 and other infectious agents is typically restricted to detecting antigen-specific antibodies in the serum. Rarely does immune monitoring entail assessment of the memory B-cell compartment itself, although it is these cells that engage in secondary antibody responses capable of mediating immune protection when pre-existing antibodies fail to prevent re-infection. There are few techniques that are capable of detecting rare antigen-specific B cells while also providing information regarding their relative abundance, class/subclass usage and functional affinity. In theory, the ELISPOT/FluoroSpot (collectively ImmunoSpot) assay platform is ideally suited for antigen-specific B-cell assessments since it provides this information at single-cell resolution for individual antibody-secreting cells (ASC). Here, we tested the hypothesis that antigen-coating efficiency could be universally improved across a diverse set of viral antigens if the standard direct (non-specific, low affinity) antigen absorption to the membrane was substituted by high-affinity capture. Specifically, we report an enhancement in assay sensitivity and a reduction in required protein concentrations through the capture of recombinant proteins via their encoded hexahistidine (6XHis) affinity tag. Affinity tag antigen coating enabled detection of SARS-CoV-2 Spike receptor binding domain (RBD)-reactive ASC, and also significantly improved assay performance using additional control antigens. Collectively, establishment of a universal antigen-coating approach streamlines characterization of the memory B-cell compartment after SARS-CoV-2 infection or COVID-19 vaccinations, and facilitates high-throughput immune-monitoring efforts of large donor cohorts in general.


Assuntos
Antígenos Virais/análise , Linfócitos B/imunologia , ELISPOT/métodos , Memória Imunológica , SARS-CoV-2/imunologia , Proteínas Virais/imunologia , Animais , COVID-19 , Histidina , Humanos , Camundongos , Oligopeptídeos , SARS-CoV-2/metabolismo
8.
J Immunol ; 207(4): 1150-1164, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34341167

RESUMO

CARD11 is a multidomain scaffold protein required for normal activation of NF-κB, JNK, and mTOR during Ag receptor signaling. Germline CARD11 mutations cause at least three types of primary immunodeficiency including CARD11 deficiency, B cell expansion with NF-κB and T cell anergy (BENTA), and CARD11-associated atopy with dominant interference of NF-κB signaling (CADINS). CADINS is uniquely caused by heterozygous loss-of-function CARD11 alleles that act as dominant negatives. CADINS patients present with frequent respiratory and skin infections, asthma, allergies, and atopic dermatitis. However, precisely how a heterozygous dominant negative CARD11 allele leads to the development of this CADINS-specific cluster of symptoms remains poorly understood. To address this, we generated mice expressing the CARD11 R30W allele originally identified in patients. We find that CARD11R30W/+ mice exhibit impaired signaling downstream of CARD11 that leads to defects in T, B, and NK cell function and immunodeficiency. CARD11R30W/+ mice develop elevated serum IgE levels with 50% penetrance that becomes more pronounced with age, but do not develop spontaneous atopic dermatitis. CARD11R30W/+ mice display reduced regulatory T cell numbers, but not the Th2 expansion observed in other mice with diminished CARD11 activity. Interestingly, the presence of mixed CARD11 oligomers in CARD11R30W/+ mice causes more severe signaling defects in T cells than in B cells, and specifically impacts IFN-γ production by NK cells, but not NK cell cytotoxicity. Our findings help explain the high susceptibility of CADINS patients to infection and suggest that the development of high serum IgE is not sufficient to induce overt atopic symptoms.


Assuntos
Linfócitos B/imunologia , Proteínas Adaptadoras de Sinalização CARD/imunologia , Imunoglobulina E/imunologia , Células Matadoras Naturais/imunologia , Transdução de Sinais/imunologia , Linfócitos T/imunologia , Alelos , Animais , Heterozigoto , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos C57BL
9.
Sci Immunol ; 6(62)2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34376481

RESUMO

To understand how a protective immune response against SARS-CoV-2 develops over time, we integrated phenotypic, transcriptional and repertoire analyses on PBMCs from mild and severe COVID-19 patients during and after infection, and compared them to healthy donors (HD). A type I IFN-response signature marked all the immune populations from severe patients during the infection. Humoral immunity was dominated by IgG production primarily against the RBD and N proteins, with neutralizing antibody titers increasing post infection and with disease severity. Memory B cells, including an atypical FCRL5+ T-BET+ memory subset, increased during the infection, especially in patients with mild disease. A significant reduction of effector memory, CD8+ T cells frequency characterized patients with severe disease. Despite such impairment, we observed robust clonal expansion of CD8+ T lymphocytes, while CD4+ T cells were less expanded and skewed toward TCM and TH2-like phenotypes. MAIT cells were also expanded, but only in patients with mild disease. Terminally differentiated CD8+ GZMB+ effector cells were clonally expanded both during the infection and post-infection, while CD8+ GZMK+ lymphocytes were more expanded post-infection and represented bona fide memory precursor effector cells. TCR repertoire analysis revealed that only highly proliferating T cell clonotypes, which included SARS-CoV-2-specific cells, were maintained post-infection and shared between the CD8+ GZMB+ and GZMK+ subsets. Overall, this study describes the development of immunity against SARS-CoV-2 and identifies an effector CD8+ T cell population with memory precursor-like features.


Assuntos
COVID-19/genética , COVID-19/imunologia , Interações Hospedeiro-Patógeno/imunologia , Imunofenotipagem , SARS-CoV-2/imunologia , Transcriptoma , Adulto , Idoso , Anticorpos Antivirais/imunologia , Linfócitos B/imunologia , Linfócitos B/metabolismo , Biomarcadores , COVID-19/virologia , Plasticidade Celular/genética , Plasticidade Celular/imunologia , Evolução Clonal/imunologia , Feminino , Perfilação da Expressão Gênica , Humanos , Isotipos de Imunoglobulinas/imunologia , Memória Imunológica , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo
10.
Int J Mol Sci ; 22(16)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34445605

RESUMO

Coronavirus disease (COVID-19) is a contagious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This case report presents a patient who had difficulty eradicating the corona virus due to being treated with Rituximab, which depletes B lymphocyte cells and therefore disables the production of neutralizing antibodies. The combined use of external anti-viral agents like convalescent plasma, IVIG and Remdesivir successfully helped the patient's immune system to eradicate the virus without B-cell population recovery. In vitro studies showed that convalescent plasma is the main agent that helped in eradicating the virus.


Assuntos
Anticorpos Antivirais/imunologia , Linfócitos B/imunologia , COVID-19/tratamento farmacológico , COVID-19/imunologia , COVID-19/terapia , SARS-CoV-2/imunologia , Monofosfato de Adenosina/análogos & derivados , Alanina/análogos & derivados , Animais , Anticorpos Neutralizantes/uso terapêutico , Antivirais/uso terapêutico , COVID-19/diagnóstico por imagem , Chlorocebus aethiops , Humanos , Imunização Passiva , Hospedeiro Imunocomprometido , Rituximab/uso terapêutico , Linfócitos T/imunologia , Células Vero
12.
Eur Rev Med Pharmacol Sci ; 25(15): 5057-5062, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34355378

RESUMO

OBJECTIVE: Complete blood count parameters are frequently altered in COVID-19 patients. Leucopenia and lymphopenia are the most common findings. This is not specific to COVID-19 as similar alterations are found in various other viral infections. This work is intended to summarize the evidence regarding white blood cell and lymphocyte subset alterations in COVID-19 and their clinical implications. MATERIALS AND METHODS: A PubMed search was conducted to identify relevant original studies. Articles not available in English or referring exclusively to pediatric patients were excluded. The study was designed as a narrative review from its inception. RESULTS: Complete white blood cell number and lymphocytes may be reduced in COVID-19 patients. Circulating CD4+ cells (helper T lymphocytes), CD8+ cells (cytotoxic T lymphocytes), regulatory T cells and natural killer (NK) cells may be reduced, with a greater reduction observed in critically ill patients. CD4+ and regulatory cell deficiencies may contribute to the cytokine storm and subsequent tissue damage observed in severe COVID-19 infection. NK and CD8+ cell deficiency might delay infection clearance. These aberrations of cellular immunity may contribute significantly to the pathogenesis of the disease. Alterations observed in monocyte function can also be implicated as they are effector cells responsible for tissue damage and remodeling. B cell dysfunction and maturation abnormalities have also been reported, suggesting that the virus also impairs humoral immunity. CONCLUSIONS: Lymphocyte subset abnormalities may be useful prognostic biomarkers for COVID-19, with circulating CD8+ cell count being the most promising as a predictor of severe disease requiring mechanical ventilation and mortality.


Assuntos
COVID-19/imunologia , Subpopulações de Linfócitos/imunologia , Subpopulações de Linfócitos/virologia , Monócitos/imunologia , Monócitos/virologia , Linfócitos B/imunologia , Linfócitos B/virologia , COVID-19/virologia , Humanos , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/virologia , Linfócitos T/imunologia , Linfócitos T/virologia
13.
Front Immunol ; 12: 721738, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34456929

RESUMO

Here, we described the case of a B cell-deficient patient after CD19 CAR-T cell therapy for refractory B cell Non-Hodgkin Lymphoma with protracted coronavirus disease 2019 (COVID-19). For weeks, this patient only inefficiently contained the virus while convalescent plasma transfusion correlated with virus clearance. Interestingly, following convalescent plasma therapy natural killer cells matured and virus-specific T cells expanded, presumably allowing virus clearance and recovery from the disease. Our findings, thus, suggest that convalescent plasma therapy can activate cellular immune responses to clear SARS-CoV-2 infections. If confirmed in larger clinical studies, these data could be of general importance for the treatment of COVID-19 patients.


Assuntos
Linfócitos B , COVID-19/imunologia , COVID-19/terapia , Síndromes de Imunodeficiência/imunologia , Imunoterapia Adotiva , Células Matadoras Naturais/imunologia , Linfócitos T/imunologia , Linfócitos B/imunologia , COVID-19/complicações , Feminino , Humanos , Imunização Passiva , Imunoglobulinas Intravenosas , Síndromes de Imunodeficiência/complicações , Ativação Linfocitária , Linfopoese , SARS-CoV-2 , Carga Viral
14.
EBioMedicine ; 70: 103539, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34391087

RESUMO

BACKGROUND: In recent months numerous health care professional acquired COVID-19 at the workplace resulting in significant shortages in medical and nursing staff. We investigated how prior COVID-19 affects SARS-CoV-2 vaccination and how such knowledge could facilitate frugal vaccination strategies. METHODS: In a cohort of 41 healthcare professionals with (n=14) and without (n=27) previous SARS-CoV-2 infection, we assessed the immune status before, during and after vaccination with BNT162b2. The humoral immune response was assessed by receptor binding domain ELISA and different SARS-CoV-2 neutralisation assays using wildtype and pseudo-typed viruses. T cell immunity against SARS-CoV-2 surface and nucleocapsid peptides were studied using interferon-γ release assays and intracellular flow cytometry. Vaccine-related side effects were captured. FINDINGS: Prior COVID-19 resulted in improved vaccine responses both in the B and T cell compartment. In vaccine recipients with prior COVID-19, the first vaccine dose induced high antibody concentrations comparable to seronegative vaccine recipients after two injections. This translated into more efficient neutralisation of virus particles, even more pronounced than expected from the RBD ELISA results. Furthermore, T cell responses were stronger in convalescents and particularly strong against the SARS-CoV-2 nucleocapsid protein. INTERPRETATION: Herein, we corroborate recent findings suggesting that in convalescents a single vaccine dose is sufficient to boost adequate in vitro neutralisation of SARS-CoV-2 and therefore may be sufficient to induce adequate protection against severe COVID-19. New spike mutated virus variants render the highly conserved nucleocapsid protein - eliciting strong SARS-CoV-2 specific T cell immunity - an interesting additional vaccine target. FUNDING: Christian Doppler Research Association, Johannes Kepler University Linz.


Assuntos
Linfócitos B/imunologia , Vacinas contra COVID-19/imunologia , COVID-19/imunologia , SARS-CoV-2/imunologia , Linfócitos T/imunologia , Adulto , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/virologia , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Pessoal de Saúde , Humanos , Imunidade Humoral/imunologia , Masculino , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinação/métodos
15.
Clin Immunol ; 230: 108825, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34403816

RESUMO

We have recently introduced multiple reaction monitoring (MRM) mass spectrometry as a novel tool for glycan biomarker research and discovery. Herein, we employ this technique to characterize the site-specific glycan alterations associated with primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC). Glycopeptides associated with disease severity were also identified. Multinomial regression modelling was employed to construct and validate multi-analyte diagnostic models capable of accurately distinguishing PBC, PSC, and healthy controls from one another (AUC = 0.93 ± 0.03). Finally, to investigate how disease-relevant environmental factors can influence glycosylation, we characterized the ability of bile acids known to be differentially expressed in PBC to alter glycosylation. We hypothesize that this could be a mechanism by which altered self-antigens are generated and become targets for immune attack. This work demonstrates the utility of the MRM method to identify diagnostic site-specific glycan classifiers capable of distinguishing even related autoimmune diseases from one another.


Assuntos
Autoimunidade , Colangite Esclerosante/imunologia , Cirrose Hepática Biliar/imunologia , Polissacarídeos/imunologia , Linfócitos B/imunologia , Linfócitos B/metabolismo , Ácidos e Sais Biliares/sangue , Ácidos e Sais Biliares/imunologia , Biomarcadores/sangue , Estudos de Casos e Controles , Colangite Esclerosante/sangue , Colangite Esclerosante/diagnóstico , Diagnóstico Diferencial , Glicômica/métodos , Glicopeptídeos/sangue , Glicopeptídeos/imunologia , Glicosilação , Humanos , Cirrose Hepática Biliar/sangue , Cirrose Hepática Biliar/diagnóstico , Polissacarídeos/sangue , Espectrometria de Massas por Ionização por Electrospray/métodos
17.
Immunol Cell Biol ; 99(8): 796-799, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34355822

RESUMO

The B-cell response to COVID-19 vaccines in convalescent individuals.


Assuntos
COVID-19 , SARS-CoV-2 , Anticorpos Antivirais , Linfócitos B/imunologia , Vacinas contra COVID-19 , Humanos , Memória Imunológica , Caminhada
18.
Science ; 373(6552)2021 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-34437125

RESUMO

Germinal centers (GCs) are the site of immunoglobulin somatic hypermutation and affinity maturation, processes essential to an effective antibody response. The formation of GCs has been studied in detail, but less is known about what leads to their regression and eventual termination, factors that ultimately limit the extent to which antibodies mature within a single reaction. We show that contraction of immunization-induced GCs is immediately preceded by an acute surge in GC-resident Foxp3+ T cells, attributed at least partly to up-regulation of the transcription factor Foxp3 by T follicular helper (TFH) cells. Ectopic expression of Foxp3 in TFH cells is sufficient to decrease GC size, implicating the natural up-regulation of Foxp3 by TFH cells as a potential regulator of GC lifetimes.


Assuntos
Linfócitos B/imunologia , Linfócitos T CD4-Positivos/imunologia , Fatores de Transcrição Forkhead/genética , Centro Germinativo/imunologia , Células T Auxiliares Foliculares/metabolismo , Linfócitos T Reguladores/imunologia , Animais , Linfócitos T CD4-Positivos/fisiologia , Fatores de Transcrição Forkhead/metabolismo , Genes Codificadores dos Receptores de Linfócitos T , Centro Germinativo/citologia , Imunização , Imunofenotipagem , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Análise de Célula Única , Células T Auxiliares Foliculares/imunologia , Linfócitos T Reguladores/fisiologia , Regulação para Cima
19.
Front Immunol ; 12: 690534, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34367150

RESUMO

High quality medical assistance and preventive strategies, including pursuing a healthy lifestyle, result in a progressively growing percentage of older people. The population and workforce is aging in all countries of the world. It is widely recognized that older individuals show an increased susceptibility to infections and a reduced response to vaccination suggesting that the aged immune system is less able to react and consequently protect the organism. The SARS-CoV-2 pandemic is dramatically showing us that the organism reacts to novel pathogens in an age-dependent manner. The decline of the immune system observed in aging remains unclear. We aimed to understand the role of B cells. We analyzed peripheral blood from children (4-18 years); young people (23-60 years) and elderly people (65-91 years) by flow cytometry. We also measured antibody secretion by ELISA following a T-independent stimulation. Here we show that the elderly have a significant reduction of CD27dull memory B cells, a population that bridges innate and adaptive immune functions. In older people, memory B cells are mostly high specialized antigen-selected CD27bright. Moreover, after in vitro stimulation with CpG, B cells from older individuals produced significantly fewer IgM and IgA antibodies compared to younger individuals. Aging is a complex process characterized by a functional decline in multiple physiological systems. The immune system of older people is well equipped to react to often encountered antigens but has a low ability to respond to new pathogens.


Assuntos
Envelhecimento/imunologia , Linfócitos B/imunologia , COVID-19 , Memória Imunológica , Pandemias , SARS-CoV-2/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , COVID-19/epidemiologia , COVID-19/imunologia , Criança , Pré-Escolar , Citocinas/imunologia , Feminino , Humanos , Imunoglobulina A/imunologia , Imunoglobulina M/imunologia , Masculino , Pessoa de Meia-Idade
20.
Rev Med Virol ; 31(4): e2195, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34260780

RESUMO

Currently severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission has been on the rise worldwide. Predicting outcome in COVID-19 remains challenging, and the search for more robust predictors continues. We made a systematic meta-analysis on the current literature from 1 January 2020 to 15 August 2020 that independently evaluated 32 circulatory immunological signatures that were compared between patients with different disease severity was made. Their roles as predictors of disease severity were determined as well. A total of 149 distinct studies that evaluated ten cytokines, four antibodies, four T cells, B cells, NK cells, neutrophils, monocytes, eosinophils and basophils were included. Compared with the non-severe patients of COVID-19, serum levels of Interleukins (IL)-2, IL-2R, IL-4, IL-6, IL-8, IL-10 and tumor necrosis factor α were significantly up-regulated in severe patients, with the largest inter-group differences observed for IL-6 and IL-10. In contrast, IL-5, IL-1ß and Interferon (IFN)-γ did not show significant inter-group difference. Four mediators of T cells count, including CD3+ T, CD4+ T, CD8+ T, CD4+ CD25+ CD127- Treg, together with CD19+ B cells count and CD16+ CD56+ NK cells were all consistently and significantly depressed in severe group than in non-severe group. SARS-CoV-2 specific IgA and IgG antibodies were significantly higher in severe group than in non-severe group, while IgM antibody in the severe patients was slightly lower than those in the non-severe patients, and IgE antibody showed no significant inter-group differences. The combination of cytokines, especially IL-6 and IL-10, and T cell related immune signatures can be used as robust biomarkers to predict disease severity following SARS-CoV-2 infection.


Assuntos
COVID-19/imunologia , SARS-CoV-2/imunologia , Anticorpos Antivirais/imunologia , Linfócitos B/imunologia , COVID-19/patologia , Citocinas/metabolismo , Humanos , Células Matadoras Naturais/imunologia , Leucócitos/imunologia , Índice de Gravidade de Doença , Linfócitos T/imunologia
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