Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 80.271
Filtrar
1.
Medicine (Baltimore) ; 99(36): e20993, 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32898991

RESUMO

Radiotherapy (RT) can affect the immune function of patients with cancer. The purpose of this study was to investigate the effect of RT on lymphocyte and its subsets in patients with esophageal cancer (EC).All patients received RT with a mean dose of 5369 cGy (gray). Blood parameters were measured in 31 patients on 3 occasions (before, at the end of radiotherapy, and at 3 months follow-up). The whole blood count and lymphocyte subsets were measured and correlated with short time efficiency and radiation dose parameters.White blood count (WBC) and lymphocyte count (ALC) were greatly decreased at the end of radiotherapy, and the percentages of CD3+, CD3+CD8+ T cells were significantly increased, on the other hand, a decrease in the CD4/CD8 ratio was observed. The percentages of CD3-CD16/56+NK cells and CD19+ B cell were decreased at the end of RT compared with prior RT. The percentages of CD3+ T cells before RT and the WBC and ALC count after RT can be used as prognostic indicators for survival. The PTV dose can cause significant changes in lymphocytes count after RT. CD3+T cells after RT were significantly correlated with mean heart dose and heart V50.Our study identified that RT causes changes in lymphocyte subsets, and these changes may indicate differences in immune function between individuals. Radiotherapy plan should be designed to minimize normal tissue dose to reduce the impact on WBC and lymphocytes.


Assuntos
Carcinoma de Células Escamosas/radioterapia , Neoplasias Esofágicas/radioterapia , Subpopulações de Linfócitos/imunologia , Idoso , Linfócitos B/imunologia , Linfócitos T CD8-Positivos/imunologia , Carcinoma de Células Escamosas/patologia , Neoplasias Esofágicas/patologia , Feminino , Humanos , Contagem de Linfócitos , Masculino , Estudos Retrospectivos
3.
Eur J Immunol ; 50(9): 1283-1294, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32910469

RESUMO

Studies on the interactions between SARS-CoV-2 and humoral immunity are fundamental to elaborate effective therapies including vaccines. We used polychromatic flow cytometry, coupled with unsupervised data analysis and principal component analysis (PCA), to interrogate B cells in untreated patients with COVID-19 pneumonia. COVID-19 patients displayed normal plasma levels of the main immunoglobulin classes, of antibodies against common antigens or against antigens present in common vaccines. However, we found a decreased number of total and naïve B cells, along with decreased percentages and numbers of memory switched and unswitched B cells. On the contrary, IgM+ and IgM- plasmablasts were significantly increased. In vitro cell activation revealed that B lymphocytes showed a normal proliferation index and number of dividing cells per cycle. PCA indicated that B-cell number, naive and memory B cells but not plasmablasts clustered with patients who were discharged, while plasma IgM level, C-reactive protein, D-dimer, and SOFA score with those who died. In patients with pneumonia, the derangement of the B-cell compartment could be one of the causes of the immunological failure to control SARS-Cov2, have a relevant influence on several pathways, organs and systems, and must be considered to develop vaccine strategies.


Assuntos
Anticorpos Antivirais/sangue , Linfócitos B/imunologia , Betacoronavirus/patogenicidade , Infecções por Coronavirus/imunologia , Isotipos de Imunoglobulinas/sangue , Pulmão/imunologia , Pneumonia Viral/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/classificação , Linfócitos B/virologia , Betacoronavirus/imunologia , Proteína C-Reativa/imunologia , Estudos de Casos e Controles , Proliferação de Células , Infecções por Coronavirus/mortalidade , Infecções por Coronavirus/patologia , Infecções por Coronavirus/virologia , Estudos Transversais , Citocinas/genética , Citocinas/imunologia , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/imunologia , Humanos , Imunidade Humoral , Memória Imunológica , Pulmão/patologia , Pulmão/virologia , Ativação Linfocitária , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Escores de Disfunção Orgânica , Pandemias , Pneumonia Viral/mortalidade , Pneumonia Viral/patologia , Pneumonia Viral/virologia , Cultura Primária de Células , Índice de Gravidade de Doença , Análise de Sobrevida
5.
Nature ; 584(7820): 274-278, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32760003

RESUMO

Colonization by the microbiota causes a marked stimulation of B cells and induction of immunoglobulin, but mammals colonized with many taxa have highly complex and individualized immunoglobulin repertoires1,2. Here we use a simplified model of defined transient exposures to different microbial taxa in germ-free mice3 to deconstruct how the microbiota shapes the B cell pool and its functional responsiveness. We followed the development of the immunoglobulin repertoire in B cell populations, as well as single cells by deep sequencing. Microbial exposures at the intestinal mucosa generated oligoclonal responses that differed from those of germ-free mice, and from the diverse repertoire that was generated after intravenous systemic exposure to microbiota. The IgA repertoire-predominantly to cell-surface antigens-did not expand after dose escalation, whereas increased systemic exposure broadened the IgG repertoire to both microbial cytoplasmic and cell-surface antigens. These microbial exposures induced characteristic immunoglobulin heavy-chain repertoires in B cells, mainly at memory and plasma cell stages. Whereas sequential systemic exposure to different microbial taxa diversified the IgG repertoire and facilitated alternative specific responses, sequential mucosal exposure produced limited overlapping repertoires and the attrition of initial IgA binding specificities. This shows a contrast between a flexible response to systemic exposure with the need to avoid fatal sepsis, and a restricted response to mucosal exposure that reflects the generic nature of host-microbial mutualism in the mucosa.


Assuntos
Linfócitos B/citologia , Linfócitos B/imunologia , Imunidade nas Mucosas/imunologia , Mucosa Intestinal/imunologia , Mucosa Intestinal/microbiologia , Simbiose/imunologia , Administração Intravenosa , Administração Oral , Animais , Clostridiales/imunologia , Clostridiales/isolamento & purificação , Escherichia coli/imunologia , Escherichia coli/isolamento & purificação , Feminino , Vida Livre de Germes , Imunoglobulina A/química , Imunoglobulina A/imunologia , Imunoglobulina G/química , Imunoglobulina G/imunologia , Cadeias Pesadas de Imunoglobulinas/imunologia , Memória Imunológica/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Plasmócitos/citologia , Plasmócitos/imunologia , Priming de Repetição
6.
Science ; 369(6506): 984-988, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32820125

RESUMO

Germinal center (GC) responses potentiate the generation of follicular regulatory T (TFR) cells. However, the molecular cues driving TFR cell formation remain unknown. Here, we show that sclerostin domain-containing protein 1 (SOSTDC1), secreted by a subpopulation of follicular helper T (TFH) cells and T-B cell border-enriched fibroblastic reticular cells, is developmentally required for TFR cell generation. Fate tracking and transcriptome assessment in reporter mice establishes SOSTDC1-expressing TFH cells as a distinct T cell population that develops after SOSTDC1- TFH cells and loses the ability to help B cells for antibody production. Notably, Sostdc1 ablation in TFH cells results in substantially reduced TFR cell numbers and consequently elevated GC responses. Mechanistically, SOSTDC1 blocks the WNT-ß-catenin axis and facilitates TFR cell differentiation.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Reguladores/imunologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Linfócitos B/imunologia , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Centro Germinativo/imunologia , Ativação Linfocitária/genética , Ativação Linfocitária/imunologia , Contagem de Linfócitos , Camundongos , Camundongos Mutantes , Proteínas Wnt/metabolismo , beta Catenina/metabolismo
7.
Signal Transduct Target Ther ; 5(1): 156, 2020 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-32796814

RESUMO

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


Assuntos
Linfócitos B/imunologia , Betacoronavirus/patogenicidade , Infecções por Coronavirus/imunologia , Imunidade Celular , Imunidade Humoral , Pneumonia Viral/imunologia , Linfócitos T/imunologia , Antígenos Virais/genética , Antígenos Virais/imunologia , Linfócitos B/classificação , Linfócitos B/virologia , Betacoronavirus/imunologia , Estudos de Casos e Controles , China , Convalescença , Infecções por Coronavirus/genética , Infecções por Coronavirus/patologia , Infecções por Coronavirus/virologia , Progressão da Doença , Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Interações Hospedeiro-Patógeno/imunologia , Humanos , Memória Imunológica , Pandemias , Pneumonia Viral/genética , Pneumonia Viral/patologia , Pneumonia Viral/virologia , Receptores de Antígenos de Linfócitos B/classificação , Receptores de Antígenos de Linfócitos B/genética , Receptores de Antígenos de Linfócitos B/imunologia , Receptores de Antígenos de Linfócitos T/classificação , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/imunologia , Índice de Gravidade de Doença , Análise de Célula Única , Linfócitos T/classificação , Linfócitos T/virologia
8.
Monoclon Antib Immunodiagn Immunother ; 39(4): 107-111, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32762609

RESUMO

In this hypothesis, we address the biological/immunological pathway leading to severe disease or death after infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The underlying immune response is described with "original antigenic sin" (OAS) whereby previous infections influence the response to future virus encounters. We cite evidence for OAS-induced immunopathology in HIV-1 disease. We hypothesize that similar immune abnormalities can occur after infection with SARS-CoV-2. This hypothesis is supported by recent analysis of the antibodies in infected patients demonstrating serological and B cell abnormalities. The concept of symmetrical clonal regulation developed earlier for the immune network illustrates the pathway suggested by our hypothesis and may be helpful to develop strategies avoiding severe coronavirus disease 2019.


Assuntos
Anticorpos Antivirais/imunologia , Linfócitos B/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/imunologia , Evasão da Resposta Imune/imunologia , Pneumonia Viral/imunologia , Anticorpos Monoclonais/imunologia , Infecções por Coronavirus/patologia , Reações Cruzadas/imunologia , Síndrome da Liberação de Citocina/imunologia , HIV/imunologia , HIV-1/imunologia , Humanos , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Memória Imunológica/imunologia , Pandemias , Pneumonia Viral/patologia
10.
Nat Commun ; 11(1): 3924, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32764665

RESUMO

Several studies show that the immunosuppressive drugs targeting the interleukin-6 (IL-6) receptor, including tocilizumab, ameliorate lethal inflammatory responses in COVID-19 patients infected with SARS-CoV-2. Here, by employing single-cell analysis of the immune cell composition of two severe-stage COVID-19 patients prior to and following tocilizumab-induced remission, we identify a monocyte subpopulation that contributes to the inflammatory cytokine storms. Furthermore, although tocilizumab treatment attenuates the inflammation, immune cells, including plasma B cells and CD8+ T cells, still exhibit robust humoral and cellular antiviral immune responses. Thus, in addition to providing a high-dimensional dataset on the immune cell distribution at multiple stages of the COVID-19, our work also provides insights into the therapeutic effects of tocilizumab, and identifies potential target cell populations for treating COVID-19-related cytokine storms.


Assuntos
Anticorpos Monoclonais Humanizados/efeitos adversos , Betacoronavirus/imunologia , Infecções por Coronavirus/imunologia , Citocinas/imunologia , Monócitos/imunologia , Pneumonia Viral/imunologia , Anticorpos Monoclonais Humanizados/administração & dosagem , Linfócitos B/efeitos dos fármacos , Linfócitos B/imunologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Biologia Computacional , Infecções por Coronavirus/sangue , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/virologia , Citocinas/sangue , Humanos , Inflamação/tratamento farmacológico , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Pandemias , Pneumonia Viral/sangue , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/virologia , Receptores de Interleucina-6/imunologia , Análise de Célula Única/métodos
11.
PLoS Pathog ; 16(7): e1008701, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32735617

RESUMO

Gammaherpesviruses have evolved various strategies to take advantage of host cellular factors or signaling pathways to establish a lifelong latent infection. Like the human gammaherpesvirus Epstein-Barr virus, murine gammaherpesvirus 68 (MHV68) establishes and maintains latency in the memory B cells during infection of laboratory mice. We have previously shown that MHV68 can immortalize fetal liver-derived B cells that induce lymphomas when injected into immunodeficient mice. Here we identify interleukin 16 (IL16) as a most abundantly expressed cytokine in MHV68-immortalized B cells and show that MHV68 infection elevates IL16 expression. IL16 is not important for MHV68 lytic infection but plays a critical role in MHV68 reactivation from latency. IL16 deficiency increases MHV68 lytic gene expression in MHV68-immortalized B cells and enhances reactivation from splenic latency. Correlatively, IL16 deficiency increases the frequency of MHV68-infected plasma cells that can be attributed to enhanced MHV68 reactivation. Furthermore, similar to TPA-mediated lytic replication of Kaposi's sarcoma-associated herpesvirus, IL16 deficiency markedly induces Tyr705 STAT3 de-phosphorylation and elevates p21 expression, which can be counteracted by the tyrosine phosphatase inhibitor orthovanadate. Importantly, orthovanadate strongly blocks MHV68 lytic gene expression mediated by IL16 deficiency. These data demonstrate that virus-induced IL16 does not directly participate in MHV68 lytic replication, but rather inhibits virus reactivation to facilitate latent infection, in part through the STAT3-p21 axis.


Assuntos
Infecções por Herpesviridae/metabolismo , Interleucina-16/metabolismo , Infecções Tumorais por Vírus/metabolismo , Ativação Viral/fisiologia , Latência Viral/fisiologia , Animais , Linfócitos B/virologia , Infecções por Herpesviridae/imunologia , Interleucina-16/imunologia , Linfoma/virologia , Camundongos , Rhadinovirus/imunologia , Rhadinovirus/metabolismo
12.
Ecotoxicol Environ Saf ; 202: 110912, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800247

RESUMO

Occupational exposure to pesticides has been identified as a factor that predisposes to disorders of the immune system. Immunosuppression, autoimmunity, cancer of various organs and other diseases in people who apply these products have been reported by the studies. This study aimed to investigate the relationship between occupational exposure to pesticides and the immunological profile in 43 farmers exposed to mixtures of pesticides for at least 15 years. A control group composed of 30 individuals without a history of occupational exposure to pesticides was also evaluated. Peripheral blood samples were processed by flow cytometry and cells were labelled with an 8-color monoclonal antibody panel. Plasma cytokines were also measured. Significant increase in classical monocytes (p < 0.001) and dendritic cells (p < 0.001) in the exposed group was observed as well in total T cells (p = 0.04), central memory CD8 T cells (p = 0.02) and effector memory CD8 T cells (p = 0.01). On the other hand, the activation markers of T cells as the expression of CD57, HLA-DR, CD25 and CD28 were evaluated and no difference was found between groups. When the B cells were analyzed, a significant decrease in total B cells (p = 0.01), regulatory B cells (p < 0.001) and plasmablasts (p < 0.001) in the exposed group, compared to healthy controls, was observed. Pro-inflammatory IL-6 was significantly elevated (p = 0.04) in the plasma of farmers compared to that of controls. The constant antigenic stimulus that occurs during exposure to pesticides can favor the recruitment of dendritic cells and macrophages (APCs) presents in the skin and respiratory tract. In the secondary lymphoid organs, the CD4 T and B cells that process such antigens are possibly undergoing proliferative exhaustion, with the consequent depletion of all mature B subpopulations. The resulting drop in humoral immunity may be offset by an increase in the number of circulating CD8 T lymphocytes due to their cytotoxic action.


Assuntos
Poluentes Ocupacionais do Ar/toxicidade , Exposição Ocupacional/estatística & dados numéricos , Praguicidas/toxicidade , Adulto , Poluentes Ocupacionais do Ar/análise , Linfócitos B/imunologia , Brasil , Antígenos CD28/metabolismo , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Citocinas/metabolismo , Fazendeiros , Feminino , Citometria de Fluxo , Antígenos HLA-DR/metabolismo , Humanos , Subunidade alfa de Receptor de Interleucina-2 , Masculino , Pessoa de Meia-Idade , Praguicidas/análise , Praguicidas/metabolismo
13.
Science ; 369(6505): 793-799, 2020 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-32792392

RESUMO

Monoclonal antibodies (mAbs) targeting human antigen CD20 (cluster of differentiation 20) constitute important immunotherapies for the treatment of B cell malignancies and autoimmune diseases. Type I and II therapeutic mAbs differ in B cell binding properties and cytotoxic effects, reflecting differential interaction mechanisms with CD20. Here we present 3.7- to 4.7-angstrom cryo-electron microscopy structures of full-length CD20 in complexes with prototypical type I rituximab and ofatumumab and type II obinutuzumab. The structures and binding thermodynamics demonstrate that upon binding to CD20, type II mAbs form terminal complexes that preclude recruitment of additional mAbs and complement components, whereas type I complexes act as molecular seeds to increase mAb local concentration for efficient complement activation. Among type I mAbs, ofatumumab complexes display optimal geometry for complement recruitment. The uncovered mechanisms should aid rational design of next-generation immunotherapies targeting CD20.


Assuntos
Anticorpos Monoclonais Humanizados/química , Complexo Antígeno-Anticorpo/química , Antígenos CD20/química , Antineoplásicos/química , Imunoterapia , Linfoma de Células B/terapia , Rituximab/química , Anticorpos Monoclonais Humanizados/imunologia , Anticorpos Monoclonais Humanizados/uso terapêutico , Complexo Antígeno-Anticorpo/imunologia , Antígenos CD20/imunologia , Antineoplásicos/imunologia , Linfócitos B/imunologia , Ativação do Complemento , Microscopia Crioeletrônica , Humanos , Fragmentos Fab das Imunoglobulinas/química , Fragmentos Fab das Imunoglobulinas/imunologia , Ligação Proteica , Conformação Proteica , Rituximab/imunologia , Rituximab/uso terapêutico
14.
Nat Commun ; 11(1): 4166, 2020 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-32820173

RESUMO

T cells engineered to express chimeric antigen receptors (CAR-T cells) have shown impressive clinical efficacy in the treatment of B cell malignancies. However, the development of CAR-T cell therapies for solid tumors is hampered by the lack of truly tumor-specific antigens and poor control over T cell activity. Here we present an avidity-controlled CAR (AvidCAR) platform with inducible and logic control functions. The key is the combination of (i) an improved CAR design which enables controlled CAR dimerization and (ii) a significant reduction of antigen-binding affinities to introduce dependence on bivalent interaction, i.e. avidity. The potential and versatility of the AvidCAR platform is exemplified by designing ON-switch CARs, which can be regulated with a clinically applied drug, and AND-gate CARs specifically recognizing combinations of two antigens. Thus, we expect that AvidCARs will be a highly valuable platform for the development of controllable CAR therapies with improved tumor specificity.


Assuntos
Imunoterapia Adotiva/métodos , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos Quiméricos/imunologia , Linfócitos T/imunologia , Animais , Antígenos de Neoplasias/imunologia , Linfócitos B/imunologia , Linfócitos B/metabolismo , Células Cultivadas , Citocinas/imunologia , Citocinas/metabolismo , Citotoxicidade Imunológica/imunologia , Humanos , Ativação Linfocitária/imunologia , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Neoplasias/imunologia , Neoplasias/patologia , Neoplasias/terapia , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/metabolismo , Linfócitos T/metabolismo
15.
Sci Rep ; 10(1): 14179, 2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32843695

RESUMO

A novel coronavirus (SARS-CoV-2) emerged from China in late 2019 and rapidly spread across the globe, infecting millions of people and generating societal disruption on a level not seen since the 1918 influenza pandemic. A safe and effective vaccine is desperately needed to prevent the continued spread of SARS-CoV-2; yet, rational vaccine design efforts are currently hampered by the lack of knowledge regarding viral epitopes targeted during an immune response, and the need for more in-depth knowledge on betacoronavirus immunology. To that end, we developed a computational workflow using a series of open-source algorithms and webtools to analyze the proteome of SARS-CoV-2 and identify putative T cell and B cell epitopes. Utilizing a set of stringent selection criteria to filter peptide epitopes, we identified 41 T cell epitopes (5 HLA class I, 36 HLA class II) and 6 B cell epitopes that could serve as promising targets for peptide-based vaccine development against this emerging global pathogen. To our knowledge, this is the first study to comprehensively analyze all 10 (structural, non-structural and accessory) proteins from SARS-CoV-2 using predictive algorithms to identify potential targets for vaccine development.


Assuntos
Betacoronavirus/imunologia , Biologia Computacional , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/imunologia , Interações Hospedeiro-Patógeno/imunologia , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Proteínas Virais/imunologia , Sequência de Aminoácidos , Linfócitos B/imunologia , Linfócitos B/metabolismo , Betacoronavirus/classificação , Betacoronavirus/genética , Betacoronavirus/metabolismo , Biologia Computacional/métodos , Infecções por Coronavirus/metabolismo , Epitopos de Linfócito B/química , Epitopos de Linfócito T/química , Genoma Viral , Genômica/métodos , Humanos , Modelos Moleculares , Pandemias , Peptídeos/química , Peptídeos/imunologia , Filogenia , Pneumonia Viral/metabolismo , Relação Estrutura-Atividade , Linfócitos T/imunologia , Linfócitos T/metabolismo , Vacinas de Subunidades/imunologia , Proteínas Virais/química , Vacinas Virais/imunologia
16.
Nat Commun ; 11(1): 3989, 2020 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-32778653

RESUMO

Upon stimulation, B cells assume heterogeneous cell fates, with only a fraction differentiating into antibody-secreting cells (ASC). Here we investigate B cell fate programming and heterogeneity during ASC differentiation using T cell-independent models. We find that maximal ASC induction requires at least eight cell divisions in vivo, with BLIMP-1 being required for differentiation at division eight. Single cell RNA-sequencing of activated B cells and construction of differentiation trajectories reveal an early cell fate bifurcation. The ASC-destined branch requires induction of IRF4, MYC-target genes, and oxidative phosphorylation, with the loss of CD62L expression serving as a potential early marker of ASC fate commitment. Meanwhile, the non-ASC branch expresses an inflammatory signature, and maintains B cell fate programming. Finally, ASC can be further subseted based on their differential responses to ER-stress, indicating multiple development branch points. Our data thus define the cell division kinetics of B cell differentiation in vivo, and identify the molecular trajectories of B cell fate and ASC formation.


Assuntos
Células Produtoras de Anticorpos/metabolismo , Linfócitos B/imunologia , Ativação Linfocitária/fisiologia , Animais , Antígenos CD19/genética , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Imunidade , Fatores Reguladores de Interferon/metabolismo , Selectina L , Ativação Linfocitária/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator 1 de Ligação ao Domínio I Regulador Positivo/genética , Fator 1 de Ligação ao Domínio I Regulador Positivo/metabolismo , Transcriptoma
17.
Nat Commun ; 11(1): 3990, 2020 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-32778659

RESUMO

The molecular mechanisms regulating lymphocyte homing into lymph nodes are only partly understood. Here, we report that B cell-specific deletion of the X-linked gene, Cosmc, and the consequent decrease of protein O-glycosylation, induces developmental blocks of mouse B cells. After transfer into wild-type recipient, Cosmc-null B cells fail to home to lymph nodes as well as non-lymphoid organs. Enzymatic desialylation of wild-type B cells blocks their migration into lymph nodes, indicating a requirement of sialylated O-glycans for proper trafficking. Mechanistically, Cosmc-deficient B cells have normal rolling and firm arrest on high endothelium venules (HEV), thereby attributing their inefficient trafficking to alterations in the subsequent transendothelial migration step. Finally, Cosmc-null B cells have defective chemokine signaling responses. Our results thus demonstrate that Cosmc and its effects on O-glycosylation are important for controlling B cell homing.


Assuntos
Linfócitos B/metabolismo , Linfonodos/metabolismo , Chaperonas Moleculares/metabolismo , Animais , Movimento Celular , Feminino , Glicosilação , Humanos , Imunidade Humoral/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Chaperonas Moleculares/genética , Polissacarídeos/metabolismo , Transcriptoma , Vênulas
18.
Science ; 369(6503)2020 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-32732394

RESUMO

The lymphoid system is intimately involved in immunological processes. The small lymphocyte that circulates through blood into lymphoid tissues, then through the lymph and back to the blood through the thoracic duct, is able to initiate immune responses after appropriate stimulation by antigen. However, the lymphocytes found in the thymus are deficient in this ability despite the fact that the thymus plays a central role in lymphocyte production and in ensuring the normal development of immunological faculty. During embryogenesis, lymphocytes are present in the thymus before they can be identified in the circulation and in other lymphoid tissues. They become "educated" in the thymus to recognize a great diversity of peptide antigens bound to the body's own marker antigen, the major histocompatibility complex, but they are purged if they strongly react against their own self-components. Lymphocytes differentiate to become various T cell subsets and then exit through the bloodstream to populate certain areas of the lymphoid system as peripheral T lymphocytes with distinct markers and immune functions.


Assuntos
Imunoterapia , Subpopulações de Linfócitos T/imunologia , Timo/imunologia , Animais , Linfócitos B/imunologia , Diferenciação Celular , Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto/imunologia , Humanos , Linfoma/imunologia , Linfoma/terapia , Camundongos , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/terapia , Transplante de Pele , Subpopulações de Linfócitos T/citologia , Timo/citologia
19.
Nat Commun ; 11(1): 3971, 2020 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-32769993

RESUMO

Efficacy evaluation through human trials is crucial for advancing a vaccine candidate to clinics. Next-generation sequencing (NGS) can be used to quantify B cell repertoire response and trace antibody lineages during vaccination. Here, we demonstrate this application with a case study of Hecolin®, the licensed vaccine for hepatitis E virus (HEV). Four subjects are administered the vaccine following a standard three-dose schedule. Vaccine-induced antibodies exhibit a high degree of clonal diversity, recognize five conformational antigenic sites of the genotype 1 HEV p239 antigen, and cross-react with other genotypes. Unbiased repertoire sequencing is performed for seven time points over six months of vaccination, with maturation pathways characterize for a set of vaccine-induced antibodies. In addition to dynamic repertoire profiles, NGS analysis reveals differential patterns of HEV-specific antibody lineages and highlights the necessity of the long vaccine boost. Together, our study presents a quantitative strategy for vaccine evaluation in small-scale human studies.


Assuntos
Anticorpos Antivirais/imunologia , Formação de Anticorpos/imunologia , Vírus da Hepatite E/imunologia , Vacinação , Vacinas contra Hepatite Viral/imunologia , Adulto , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Especificidade de Anticorpos/imunologia , Linfócitos B/imunologia , Epitopos/imunologia , Genótipo , Vírus da Hepatite E/genética , Humanos , Fatores de Tempo , Doadores de Tecidos , Adulto Jovem
20.
N Engl J Med ; 383(6): 546-557, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32757523

RESUMO

BACKGROUND: Ofatumumab, a subcutaneous anti-CD20 monoclonal antibody, selectively depletes B cells. Teriflunomide, an oral inhibitor of pyrimidine synthesis, reduces T-cell and B-cell activation. The relative effects of these two drugs in patients with multiple sclerosis are not known. METHODS: In two double-blind, double-dummy, phase 3 trials, we randomly assigned patients with relapsing multiple sclerosis to receive subcutaneous ofatumumab (20 mg every 4 weeks after 20-mg loading doses at days 1, 7, and 14) or oral teriflunomide (14 mg daily) for up to 30 months. The primary end point was the annualized relapse rate. Secondary end points included disability worsening confirmed at 3 months or 6 months, disability improvement confirmed at 6 months, the number of gadolinium-enhancing lesions per T1-weighted magnetic resonance imaging (MRI) scan, the annualized rate of new or enlarging lesions on T2-weighted MRI, serum neurofilament light chain levels at month 3, and change in brain volume. RESULTS: Overall, 946 patients were assigned to receive ofatumumab and 936 to receive teriflunomide; the median follow-up was 1.6 years. The annualized relapse rates in the ofatumumab and teriflunomide groups were 0.11 and 0.22, respectively, in trial 1 (difference, -0.11; 95% confidence interval [CI], -0.16 to -0.06; P<0.001) and 0.10 and 0.25 in trial 2 (difference, -0.15; 95% CI, -0.20 to -0.09; P<0.001). In the pooled trials, the percentage of patients with disability worsening confirmed at 3 months was 10.9% with ofatumumab and 15.0% with teriflunomide (hazard ratio, 0.66; P = 0.002); the percentage with disability worsening confirmed at 6 months was 8.1% and 12.0%, respectively (hazard ratio, 0.68; P = 0.01); and the percentage with disability improvement confirmed at 6 months was 11.0% and 8.1% (hazard ratio, 1.35; P = 0.09). The number of gadolinium-enhancing lesions per T1-weighted MRI scan, the annualized rate of lesions on T2-weighted MRI, and serum neurofilament light chain levels, but not the change in brain volume, were in the same direction as the primary end point. Injection-related reactions occurred in 20.2% in the ofatumumab group and in 15.0% in the teriflunomide group (placebo injections). Serious infections occurred in 2.5% and 1.8% of the patients in the respective groups. CONCLUSIONS: Among patients with multiple sclerosis, ofatumumab was associated with lower annualized relapse rates than teriflunomide. (Funded by Novartis; ASCLEPIOS I and II ClinicalTrials.gov numbers, NCT02792218 and NCT02792231.).


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Crotonatos/uso terapêutico , Injeções Subcutâneas/efeitos adversos , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Toluidinas/uso terapêutico , Adulto , Anticorpos Monoclonais Humanizados/efeitos adversos , Linfócitos B , Encéfalo/patologia , Crotonatos/efeitos adversos , Progressão da Doença , Método Duplo-Cego , Feminino , Humanos , Estimativa de Kaplan-Meier , Imagem por Ressonância Magnética , Masculino , Esclerose Múltipla Recidivante-Remitente/patologia , Linfócitos T , Toluidinas/efeitos adversos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA