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1.
Front Immunol ; 11: 611004, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33343585

RESUMO

Background: SARS-CoV-2 infection represents a global health problem that has affected millions of people. The fine host immune response and its association with the disease course have not yet been fully elucidated. Consequently, we analyze circulating B cell subsets and their possible relationship with COVID-19 features and severity. Methods: Using a multiparametric flow cytometric approach, we determined B cell subsets frequencies from 52 COVID-19 patients, grouped them by hierarchical cluster analysis, and correlated their values with clinical data. Results: The frequency of CD19+ B cells is increased in severe COVID-19 compared to mild cases. Specific subset frequencies such as transitional B cell subsets increase in mild/moderate cases but decrease with the severity of the disease. Memory B compartment decreased in severe and critical cases, and antibody-secreting cells are increased according to the severity of the disease. Other non-typical subsets such as double-negative B cells also showed significant changes according to disease severity. Globally, these differences allow us to identify severity-associated patient clusters with specific altered subsets. Finally, respiratory parameters, biomarkers of inflammation, and clinical scores exhibited correlations with some of these subpopulations. Conclusions: The severity of COVID-19 is accompanied by changes in the B cell subpopulations, either immature or terminally differentiated. Furthermore, the existing relationship of B cell subset frequencies with clinical and laboratory parameters suggest that these lymphocytes could serve as potential biomarkers and even active participants in the adaptive antiviral response mounted against SARS-CoV-2.


Assuntos
Subpopulações de Linfócitos B , Adulto , Idoso , Idoso de 80 Anos ou mais , Subpopulações de Linfócitos B/imunologia , Subpopulações de Linfócitos B/metabolismo , Subpopulações de Linfócitos B/patologia , /imunologia , Feminino , Citometria de Fluxo , Humanos , Masculino , Pessoa de Meia-Idade , /metabolismo , Índice de Gravidade de Doença
2.
Sci Rep ; 10(1): 20836, 2020 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-33257775

RESUMO

Impaired immune responses have been hypothesised to be a possible trigger of unfavourable outcomes in coronavirus disease 2019 (COVID-19). We aimed to characterise IgM memory B cells in patients with COVID-19 admitted to an internal medicine ward in Northern Italy. Overall, 66 COVID-19 patients (mean age 74 ± 16.6 years; 29 females) were enrolled. Three patients (4.5%; 1 female) had been splenectomised and were excluded from further analyses. Fifty-five patients (87.3%) had IgM memory B cell depletion, and 18 (28.6%) died during hospitalisation (cumulative incidence rate 9.26/100 person-week; 5.8-14.7 95% CI). All patients who died had IgM memory B cell depletion. A superimposed infection was found in 6 patients (9.5%), all of them having IgM memory B cell depletion (cumulative incidence rate 3.08/100 person-week; 1.3-6.8 95% CI). At bivariable analyses, older age, sex, number of comorbidities, and peripheral blood lymphocyte count < 1500/µl were not correlated with IgM memory B cell depletion. A discrete-to-marked reduction of the B-cell compartment was also noticed in autoptic spleen specimens of two COVID-19 patients. We conclude that IgM memory B cells are commonly depleted in COVID-19 patients and this correlates with increased mortality and superimposed infections.


Assuntos
Linfócitos B/citologia , Mortalidade Hospitalar , Memória Imunológica/imunologia , Depleção Linfocítica , Adulto , Idoso , Idoso de 80 Anos ou mais , Subpopulações de Linfócitos B/citologia , Subpopulações de Linfócitos B/imunologia , Linfócitos B/imunologia , Feminino , Humanos , Imunoglobulina M/sangue , Estudos Longitudinais , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Baço/citologia , Baço/imunologia
4.
Ann Hematol ; 99(10): 2215-2229, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32856140

RESUMO

The B cell surface antigen CD19 is a target for treating B cell malignancies, such as B cell precursor acute lymphoblastic leukemia and B cell non-Hodgkin lymphoma. The BiTE® immuno-oncology platform includes blinatumomab, which is approved for relapsed/refractory B cell precursor acute lymphoblastic leukemia and B cell precursor acute lymphoblastic leukemia with minimal residual disease. Blinatumomab is also being evaluated in combination with other agents (tyrosine kinase inhibitors, checkpoint inhibitors, and chemotherapy) in various treatment settings, including frontline protocols. An extended half-life BiTE molecule is also under investigation. Patients receiving blinatumomab may experience cytokine release syndrome and neurotoxicity; however, these events may be less frequent and severe than in patients receiving other CD19-targeted immunotherapies, such as chimeric antigen receptor T cell therapy. We review BiTE technology for treating malignancies that express CD19, analyzing the benefits and limitations of this bispecific T cell engager platform from clinical experience with blinatumomab.


Assuntos
Anticorpos Biespecíficos/uso terapêutico , Antígenos CD19/imunologia , Antígenos de Neoplasias/imunologia , Antineoplásicos Imunológicos/uso terapêutico , Subpopulações de Linfócitos B/imunologia , Linfoma de Células B/terapia , Leucemia-Linfoma Linfoblástico de Células Precursoras B/terapia , Adolescente , Corticosteroides/uso terapêutico , Adulto , Anticorpos Biespecíficos/administração & dosagem , Anticorpos Biespecíficos/efeitos adversos , Anticorpos Biespecíficos/economia , Antineoplásicos Imunológicos/administração & dosagem , Antineoplásicos Imunológicos/efeitos adversos , Antineoplásicos Imunológicos/economia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Criança , Ensaios Clínicos como Assunto , Terapia Combinada , Análise Custo-Benefício , Síndrome da Liberação de Citocina/etiologia , Síndrome da Liberação de Citocina/prevenção & controle , Custos de Medicamentos , Humanos , Imunoterapia Adotiva/efeitos adversos , Imunoterapia Adotiva/economia , Infusões Intravenosas , Injeções Subcutâneas , Linfoma de Células B/tratamento farmacológico , Linfoma de Células B/imunologia , Neoplasia Residual , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/imunologia , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patologia , Pré-Medicação , Qualidade de Vida , Subpopulações de Linfócitos T/imunologia , Resultado do Tratamento , Carga Tumoral , Evasão Tumoral
5.
Nat Med ; 26(10): 1623-1635, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32807934

RESUMO

Improved understanding and management of COVID-19, a potentially life-threatening disease, could greatly reduce the threat posed by its etiologic agent, SARS-CoV-2. Toward this end, we have identified a core peripheral blood immune signature across 63 hospital-treated patients with COVID-19 who were otherwise highly heterogeneous. The signature includes discrete changes in B and myelomonocytic cell composition, profoundly altered T cell phenotypes, selective cytokine/chemokine upregulation and SARS-CoV-2-specific antibodies. Some signature traits identify links with other settings of immunoprotection and immunopathology; others, including basophil and plasmacytoid dendritic cell depletion, correlate strongly with disease severity; while a third set of traits, including a triad of IP-10, interleukin-10 and interleukin-6, anticipate subsequent clinical progression. Hence, contingent upon independent validation in other COVID-19 cohorts, individual traits within this signature may collectively and individually guide treatment options; offer insights into COVID-19 pathogenesis; and aid early, risk-based patient stratification that is particularly beneficial in phasic diseases such as COVID-19.


Assuntos
Anticorpos Antivirais/imunologia , Linfócitos B/imunologia , Infecções por Coronavirus/imunologia , Citocinas/imunologia , Células Dendríticas/imunologia , Pneumonia Viral/imunologia , Linfócitos T/imunologia , Idoso , Subpopulações de Linfócitos B/imunologia , Basófilos/imunologia , Betacoronavirus , Estudos de Casos e Controles , Ciclo Celular , Quimiocina CXCL10/imunologia , Quimiocinas/imunologia , Estudos de Coortes , Infecções por Coronavirus/sangue , Progressão da Doença , Feminino , Citometria de Fluxo , Hospitalização , Humanos , Memória Imunológica , Imunofenotipagem , Interleucina-10/imunologia , Interleucina-6/imunologia , Contagem de Leucócitos , Ativação Linfocitária/imunologia , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/sangue , Prognóstico , Índice de Gravidade de Doença , Subpopulações de Linfócitos T/imunologia , Regulação para Cima
6.
Nat Immunol ; 21(9): 1082-1093, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32601467

RESUMO

Memory B cells (MBCs) are essential for long-lived humoral immunity. However, the transcription factors involved in MBC differentiation are poorly defined. Here, using single-cell RNA sequencing analysis, we identified a population of germinal center (GC) B cells in the process of differentiating into MBCs. Using an inducible CRISPR-Cas9 screening approach, we identified the hematopoietically expressed homeobox protein Hhex as a transcription factor regulating MBC differentiation. The corepressor Tle3 was also identified in the screen and was found to interact with Hhex to promote MBC development. Bcl-6 directly repressed Hhex in GC B cells. Reciprocally, Hhex-deficient MBCs exhibited increased Bcl6 expression and reduced expression of the Bcl-6 target gene Bcl2. Overexpression of Bcl-2 was able to rescue MBC differentiation in Hhex-deficient cells. We also identified Ski as an Hhex-induced transcription factor involved in MBC differentiation. These findings establish an important role for Hhex-Tle3 in regulating the transcriptional circuitry governing MBC differentiation.


Assuntos
Subpopulações de Linfócitos B/imunologia , Linfócitos B/imunologia , Proteínas Correpressoras/metabolismo , Centro Germinativo/imunologia , Proteínas de Homeodomínio/metabolismo , Fatores de Transcrição/metabolismo , Animais , Sistemas CRISPR-Cas , Diferenciação Celular , Proteínas Correpressoras/genética , Feminino , Regulação da Expressão Gênica , Proteínas de Homeodomínio/genética , Memória Imunológica , Ativação Linfocitária , Masculino , Camundongos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Proto-Oncogênicas c-bcl-6/genética , Proteínas Proto-Oncogênicas c-bcl-6/metabolismo , Análise de Sequência de RNA , Análise de Célula Única , Fatores de Transcrição/genética
7.
PLoS One ; 15(7): e0235449, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32716916

RESUMO

BACKGROUND: Several disease modifying drugs (DMDs) have been approved for the treatment of multiple sclerosis (MS), however, little is known about their differential impact on peripheral blood (PB) B cell subsets. METHODS: We performed a cross sectional study on PB B cells in MS patients treated with interferon-ß (n = 25), glatiramer acetate (n = 19), dimethyl fumarate (n = 15), fingolimod (n = 16) or natalizumab (n = 22), untreated MS patients (n = 20), and in patients with non-inflammatory neurological diseases (n = 12). Besides analyzing routine laboratory data, flow cytometry was performed to analyze naïve B cells (CD19+CD20+CD27-IgD+), non-class switched (CD19+CD20+CD27+IgD+) and class-switched memory B cells (CD19+CD20+CD27+IgD-), double negative B cells (CD19+CD20lowCD27-IgD-) and plasmablasts (CD19+CD20lowCD27+CD38++). RESULTS: Treatment associated changes were found for the overall B cell pool as well as for all B cell subsets. Natalizumab increased absolute numbers and percentage of all B cells mainly by expanding the memory B cell pool. Fingolimod decreased absolute numbers of all B cell subsets and the percentage of total B cells. Fingolimod, dimethyl fumarate and interferon-ß treatments were associated with an increase in the fraction of naïve B cells while class switched and non-class switched memory B cells showed decreased percentages. CONCLUSION: Our results highlight differential effects of DMDs on the PB B cell compartment. Across the examined treatments, a decreased percentage of memory B cells was found in dimethyl fumarate, interferon-ß and fingolimod treated patients which might contribute to the drugs' mode of action in MS. Further studies are necessary to decipher the exact role of B cell subsets during MS pathogenesis.


Assuntos
Subpopulações de Linfócitos B/efeitos dos fármacos , Linfócitos B/efeitos dos fármacos , Memória Imunológica/efeitos dos fármacos , Esclerose Múltipla/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos CD/classificação , Antígenos CD/imunologia , Antígenos CD19 , Subpopulações de Linfócitos B/classificação , Subpopulações de Linfócitos B/imunologia , Linfócitos B/imunologia , Estudos Transversais , Fumarato de Dimetilo/administração & dosagem , Feminino , Cloridrato de Fingolimode/administração & dosagem , Citometria de Fluxo , Acetato de Glatiramer/administração & dosagem , Humanos , Memória Imunológica/imunologia , Imunofenotipagem , Imunossupressores/administração & dosagem , Imunossupressores/imunologia , Interferon beta/administração & dosagem , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/sangue , Esclerose Múltipla/imunologia , Esclerose Múltipla/patologia , Natalizumab/administração & dosagem , Adulto Jovem
8.
Life Sci ; 257: 118117, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32693243

RESUMO

AIMS: B cells can promote or inhibit immune responses against breast cancer. We investigated changes in the frequency of B cells with stimulatory or regulatory capacity in breast tumor draining lymph nodes during cancer progression. MAIN METHODS: We isolated mononuclear cells from fresh axillary lymph nodes (LNs) of 44 patients with breast cancer and stained lymphocytes with antibodies against CD19, CD80, CD86, CD39 and CD73. To assess programmed death-1 (PD-1) and PD-ligand 1 (PD-L1) expression, lymphocytes were briefly stimulated, stained for CD19, PD-1 and PD-L1, and examined with flow cytometry. KEY FINDINGS: The frequency of CD80+ B cells was higher in nonmetastatic lymph nodes, while the percentage of CD86+ B cells showed a positive relationship with higher tumor grade and higher numbers of involved LNs. A small proportion of unstimulated B cells expressed PD-1 or PD-L1 but these molecules were rapidly upregulated on B cells following activation. The frequency of stimulated PD-L1+ B cells showed an inverse association with estrogen and progesterone receptor expression and a nonsignificant positive association with tumor grade. In addition, the percentage of unstimulated PD-1+ B cells was higher in patients with higher-grade tumors. CD73 expression on B cells was associated with lower numbers of involved LNs, and the frequency of CD39+ B cells was higher in patients with larger tumors. SIGNIFICANCE: CD86+, CD39+, PD-1+ and PD-L1+ B cells showed associations with poor prognostic factors, therefore their potential role in the suppression of the immune responses against breast cancer should be evaluated in greater detail.


Assuntos
Subpopulações de Linfócitos B/patologia , Linfócitos B Reguladores/patologia , Neoplasias da Mama/imunologia , Linfonodos/patologia , Adulto , Idoso , Apirase/imunologia , Axila , Subpopulações de Linfócitos B/imunologia , Linfócitos B Reguladores/imunologia , Antígeno B7-2/imunologia , Antígeno B7-H1/metabolismo , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/patologia , Feminino , Citometria de Fluxo , Humanos , Linfonodos/citologia , Linfonodos/imunologia , Pessoa de Meia-Idade , Prognóstico , Receptor de Morte Celular Programada 1/metabolismo
9.
PLoS One ; 15(7): e0235743, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645052

RESUMO

Granulomatosis with polyangiitis (GPA) is an autoimmune disease affecting mainly small blood vessels. B-cells are important in the GPA pathogenesis as precursors of autoantibody-producing cells but likely also contribute (auto)antibody-independently. This has been underlined by the effectiveness of B-cell-depletion (with Rituximab) in inducing and maintaining disease remission. Mycophenolate-mofetil (MMF) and azathioprine (AZA) are immunosuppressive therapies frequently used in GPA-patients. Interestingly, MMF-treated GPA-patients are more prone to relapses than AZA-treated patients, while little is known about the influence of these drugs on B-cells. We investigated whether MMF or AZA treatment (or their active compounds) alters the circulating B-cell subset distribution and has differential effects on in vitro B-cell proliferation and cytokine production in GPA-patients that might underlie the different relapse rate. Circulating B-cell subset frequencies were determined in samples from AZA-treated (n = 13), MMF-treated (n = 12), untreated GPA-patients (n = 19) and matched HCs (n = 41). To determine the ex vivo effects of the active compounds of MMF and AZA, MPA and 6-MP respectively, on B-cell proliferation and cytokine production, PBMCs of untreated GPA-patients (n = 29) and matched HCs (n = 30) were cultured for 3-days in the presence of CpG-oligodeoxynucleotides (CpG) with MPA or 6-MP. After restimulation (with phorbol myristate acetate, calcium-ionophore), cytokine-positive B-cell frequencies were measured. Finally, to assess the effect of MMF or AZA treatment on in vitro B-cell proliferation and cytokine production, PBMCs of MMF-treated (n = 18), and AZA-treated patients (n = 28) and HCs (n = 41) were cultured with CpG. The memory B-cell frequency was increased in AZA- compared to MMF-treated patients, while no other subset was different. The active compounds of MMF and AZA showed in vitro that MPA decreased B-cell proliferation in GPA-patients and HCs. B-cell proliferation in MMF- and AZA-treated patients was not different. Finally, the IL-6+ B-cell frequency was decreased by MPA compared to 6-MP. No differences in IL-10+, IL-6+ or TNFα+ B-cell proportions or proliferation were found in MMF- and AZA-treated patients. Our results indicate that MMF could be superior to AZA in inhibiting B-cell cytokine production in GPA-patients. Future studies should assess the effects of these immunosuppressive drugs on other immune cells to elucidate mechanisms underlying the potential differences in relapse rates.


Assuntos
Linfócitos B/imunologia , Granulomatose com Poliangiite , Imunossupressores/farmacologia , Ácido Micofenólico/farmacologia , Adulto , Idoso , Azatioprina/farmacologia , Subpopulações de Linfócitos B/imunologia , Linfócitos B/efeitos dos fármacos , Linfócitos B/metabolismo , Proliferação de Células/efeitos dos fármacos , Citocinas/metabolismo , Feminino , Citometria de Fluxo , Granulomatose com Poliangiite/tratamento farmacológico , Granulomatose com Poliangiite/imunologia , Humanos , Interleucina-6/metabolismo , Masculino , Mercaptopurina/farmacologia , Pessoa de Meia-Idade
10.
Arch Virol ; 165(10): 2249-2258, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32696270

RESUMO

While infectious bursal disease virus (IBDV) mainly targets immature B cells and causes T cell infiltration in the bursa of Fabricius (BF) of chickens, the effect of IBDV infection on the properties of T cells and relevant cytokine production in avian gut-associated lymphoid tissues (GALTs) remains unknown. Here, we show that while the CD8+ T cell subset is not affected, IBDV infection decreases the percentage of CD4+ T cells in the cecal tonsil (CT), but not in esophagus tonsil, pylorus tonsil, and Meckel's diverticulum of GALTs, in contrast to BF and spleen, in which the proportion of CD4+ cells increases upon IBDV infection. Further, IBDV infection upregulates IFN-γ, IL-10, and the T cell checkpoint receptor LAG-3 mRNA expression in BF. In contrast, in CTs, IBDV infection significantly increases the production of IFN-ß and CTLA-4 mRNA, while no significant effect is seen in the case of IFN-γ, IL-10 and LAG-3. Together, our data reveal differential modulation of T cell subsets and proinflammatory cytokine production in different lymphoid tissues during the course of IBDV infection.


Assuntos
Subpopulações de Linfócitos B/imunologia , Infecções por Birnaviridae/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Regulação da Expressão Gênica/imunologia , Doenças das Aves Domésticas/imunologia , Animais , Antígenos CD/genética , Antígenos CD/imunologia , Subpopulações de Linfócitos B/virologia , Infecções por Birnaviridae/genética , Infecções por Birnaviridae/patologia , Infecções por Birnaviridae/virologia , Bolsa de Fabricius/imunologia , Bolsa de Fabricius/virologia , Linfócitos T CD4-Positivos/virologia , Linfócitos T CD8-Positivos/virologia , Antígeno CTLA-4/genética , Antígeno CTLA-4/imunologia , Galinhas/virologia , Vírus da Doença Infecciosa da Bursa/crescimento & desenvolvimento , Vírus da Doença Infecciosa da Bursa/imunologia , Vírus da Doença Infecciosa da Bursa/patogenicidade , Interferon beta/genética , Interferon beta/imunologia , Interferon gama/genética , Interferon gama/imunologia , Interleucina-10/genética , Interleucina-10/imunologia , Mucosa Intestinal/imunologia , Mucosa Intestinal/virologia , Tonsila Palatina/imunologia , Tonsila Palatina/virologia , Doenças das Aves Domésticas/genética , Doenças das Aves Domésticas/patologia , Doenças das Aves Domésticas/virologia
11.
Shock ; 54(5): 586-594, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32604223

RESUMO

Coronavirus disease 2019 (COVID-19) is a life-threatening respiratory illness caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Its clinical presentation can vary from the asymptomatic state to acute respiratory distress syndrome (ARDS) and multi-organ dysfunction. Due to our insufficient understanding of its pathophysiology and lack of effective treatment, the morbidity and mortality of severe COVID-19 patients are high. Patients with COVID-19 develop ARDS fueled by exaggerated neutrophil influx into the lungs and cytokine storm. B-1a cells represent a unique subpopulation of B lymphocytes critical for circulating natural antibodies, innate immunity, and immunoregulation. These cells spontaneously produce natural IgM, interleukin (IL)-10, and granulocyte-monocyte colony stimulating factor (GM-CSF). Natural IgM neutralizes viruses and opsonizes bacteria, IL-10 attenuates the cytokine storm, and GM-CSF induces IgM production by B-1a cells in an autocrine manner. Indeed, B-1a cells have been shown to ameliorate influenza virus infection, sepsis, and pneumonia, all of which are similar to COVID-19. The recent discovery of B-1a cells in humans further reinforces their potentially critical role in the immune response against SARS-CoV-2 and their anticipated translational applications against viral and microbial infections. Given that B-1a cells protect against ARDS via immunoglobulin production and the anti-COVID-19 effects of convalescent plasma treatment, we recommend that studies be conducted to further examine the role of B-1a cells in the pathogenesis of COVID-19 and explore their therapeutic potential to treat COVID-19 patients.


Assuntos
Transferência Adotiva , Subpopulações de Linfócitos B/transplante , Betacoronavirus/patogenicidade , Infecções por Coronavirus/terapia , Pneumonia Viral/terapia , Transferência Adotiva/efeitos adversos , Animais , Subpopulações de Linfócitos B/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Interações Hospedeiro-Patógeno , Humanos , Pandemias , Pneumonia Viral/diagnóstico , Pneumonia Viral/imunologia , Pneumonia Viral/virologia
12.
Sci Immunol ; 5(49)2020 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-32669287

RESUMO

Although critical illness has been associated with SARS-CoV-2-induced hyperinflammation, the immune correlates of severe COVID-19 remain unclear. Here, we comprehensively analyzed peripheral blood immune perturbations in 42 SARS-CoV-2 infected and recovered individuals. We identified extensive induction and activation of multiple immune lineages, including T cell activation, oligoclonal plasmablast expansion, and Fc and trafficking receptor modulation on innate lymphocytes and granulocytes, that distinguished severe COVID-19 cases from healthy donors or SARS-CoV-2-recovered or moderate severity patients. We found the neutrophil to lymphocyte ratio to be a prognostic biomarker of disease severity and organ failure. Our findings demonstrate broad innate and adaptive leukocyte perturbations that distinguish dysregulated host responses in severe SARS-CoV-2 infection and warrant therapeutic investigation.


Assuntos
Subpopulações de Linfócitos B/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/imunologia , Neutrófilos/imunologia , Pneumonia Viral/imunologia , Linfócitos T/imunologia , Idoso , Seleção Clonal Mediada por Antígeno/imunologia , Infecções por Coronavirus/patologia , Citocinas/metabolismo , Feminino , Humanos , Imunidade Inata/imunologia , Memória Imunológica/imunologia , Ativação Linfocitária/imunologia , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/patologia
13.
Science ; 369(6508)2020 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-32669297

RESUMO

Coronavirus disease 2019 (COVID-19) is currently a global pandemic, but human immune responses to the virus remain poorly understood. We used high-dimensional cytometry to analyze 125 COVID-19 patients and compare them with recovered and healthy individuals. Integrated analysis of ~200 immune and ~50 clinical features revealed activation of T cell and B cell subsets in a proportion of patients. A subgroup of patients had T cell activation characteristic of acute viral infection and plasmablast responses reaching >30% of circulating B cells. However, another subgroup had lymphocyte activation comparable with that in uninfected individuals. Stable versus dynamic immunological signatures were identified and linked to trajectories of disease severity change. Our analyses identified three immunotypes associated with poor clinical trajectories versus improving health. These immunotypes may have implications for the design of therapeutics and vaccines for COVID-19.


Assuntos
Linfócitos B/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/imunologia , Pneumonia Viral/imunologia , Linfócitos T/imunologia , Imunidade Adaptativa , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/sangue , Subpopulações de Linfócitos B/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Citocinas/sangue , Feminino , Humanos , Memória Imunológica , Ativação Linfocitária , Masculino , Pessoa de Meia-Idade , Pandemias , Plasmócitos/imunologia , Índice de Gravidade de Doença , Subpopulações de Linfócitos T/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Fatores de Tempo , Adulto Jovem
14.
Science ; 369(6505): 818-823, 2020 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-32616673

RESUMO

Coronavirus disease 2019 (COVID-19), which is caused by infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a global pandemic. It is unclear whether convalescing patients have a risk of reinfection. We generated a rhesus macaque model of SARS-CoV-2 infection that was characterized by interstitial pneumonia and systemic viral dissemination mainly in the respiratory and gastrointestinal tracts. Rhesus macaques reinfected with the identical SARS-CoV-2 strain during the early recovery phase of the initial SARS-CoV-2 infection did not show detectable viral dissemination, clinical manifestations of viral disease, or histopathological changes. Comparing the humoral and cellular immunity between primary infection and rechallenge revealed notably enhanced neutralizing antibody and immune responses. Our results suggest that primary SARS-CoV-2 exposure protects against subsequent reinfection in rhesus macaques.


Assuntos
Betacoronavirus , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Canal Anal/virologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Subpopulações de Linfócitos B/imunologia , Betacoronavirus/imunologia , Betacoronavirus/isolamento & purificação , Betacoronavirus/fisiologia , Infecções por Coronavirus/patologia , Infecções por Coronavirus/fisiopatologia , Modelos Animais de Doenças , Interações entre Hospedeiro e Microrganismos , Imunidade Celular , Imunidade Humoral , Pulmão/diagnóstico por imagem , Pulmão/imunologia , Pulmão/patologia , Pulmão/virologia , Doenças Pulmonares Intersticiais/imunologia , Doenças Pulmonares Intersticiais/patologia , Doenças Pulmonares Intersticiais/virologia , Macaca mulatta , Nasofaringe/virologia , Pandemias , Pneumonia Viral/patologia , Pneumonia Viral/fisiopatologia , Recidiva , Subpopulações de Linfócitos T/imunologia , Carga Viral , Replicação Viral
15.
PLoS Negl Trop Dis ; 14(6): e0008358, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32589656

RESUMO

Antibody-mediated parasite killing is considered the most effective host immune response against extracellular trypanosome parasites. However, due to host-parasite co-evolution pressure, these parasites have "learned" how to hijack the host immune system via the development of immune evasion strategies. Hereby they prevent elimination and promote transmission. In the past, our group has shown that African trypanosome parasites are able to "shut down" the host B cell compartment, via the abolishment of the homeostatic B cell compartment. In line with this, we have reported that trypanosome infections result in detrimental outcomes on auto-reactive and cancer B cells. To unravel the immune mechanisms involved in these processes we adopted here a well-defined B cell vaccine model, i.e. the thymo-dependent hapten-carrier NP-CGG (4-Hydroxy-3-nitrophenylacetyl-Chicken Gamma Globulin) emulsified in Alum adjuvant. Results show that T. brucei infections abrogate the circulating titres of vaccine-induced CGG-specific as well as NP-specific IgG1+ antibodies, a hallmark of memory B cell responses in this model. This happens independently of their affinity and IFNÉ£ signalling. Next, we demonstrate that T. brucei infections also induce a decrease of anti-NP IgG3+ antibodies induced by the administration of NP coupled to Ficoll, a thymo-independent antigen. Confirming the non-specificity of the infection-associated immunopathology, this report also shows that trypanosome infections abolish vaccine-induced memory response against malaria parasite in BALB/c mice. Together, these data indicates that T. brucei infections impair every stages of B cell development, including effector plasma B cells, independently of their specificity and affinity as well as the host genetic background.


Assuntos
Subpopulações de Linfócitos B/imunologia , Plasmócitos/imunologia , Tripanossomíase Africana/imunologia , Animais , Anticorpos Antiprotozoários/imunologia , Antígenos de Protozoários/imunologia , Linfócitos B/imunologia , Modelos Animais de Doenças , Feminino , Patrimônio Genético , Interações Hospedeiro-Parasita/imunologia , Evasão da Resposta Imune , Imunidade Humoral , Imunoglobulina G , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Vacinas Protozoárias/imunologia , Trypanosoma brucei brucei
16.
Am J Respir Crit Care Med ; 202(7): 1013-1023, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32501729

RESUMO

Rationale: A subpopulation of B cells (age-associated B cells [ABCs]) is increased in mice and humans with infections or autoimmune diseases. Because depletion of these cells might be valuable in patients with certain lung diseases, the goal was to find out if ABC-like cells were at elevated levels in such patients.Objectives: To measure ABC-like cell percentages in patients with lung granulomatous diseases.Methods: Peripheral blood and BAL cells from patients with sarcoidosis, beryllium sensitivity, or hypersensitivity pneumonitis and healthy subjects were analyzed for the percentage of B cells that were ABC-like, defined by expression of CD11c, low levels of CD21, FcRL 1-5 (Fc receptor-like protein 1-5) expression, and, in some cases, T-bet.Measurements and Main Results: ABC-like cells in blood were at low percentages in healthy subjects and higher percentages in patients with sarcoidosis as well as at high percentages among BAL cells of patients with sarcoidosis, beryllium disease, and hypersensitivity pneumonitis. Treatment of patients with sarcoidosis led to reduced percentages of ABC-like cells in blood.Conclusions: Increased levels of ABC-like cells in patients with sarcoidosis may be useful in diagnosis. The increase in percentage of ABC-like cells in patients with lung granulomatous diseases and decrease in treated patients suggests that depletion of these cells may be valuable.


Assuntos
Alveolite Alérgica Extrínseca/sangue , Subpopulações de Linfócitos B/metabolismo , Beriliose/sangue , Líquido da Lavagem Broncoalveolar/citologia , Sarcoidose Pulmonar/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Alveolite Alérgica Extrínseca/imunologia , Subpopulações de Linfócitos B/imunologia , Beriliose/imunologia , Antígeno CD11c/metabolismo , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Proteínas de Membrana/metabolismo , Pessoa de Meia-Idade , Receptores de Superfície Celular/metabolismo , Receptores de Complemento 3d/metabolismo , Receptores Fc/metabolismo , Receptores Imunológicos/metabolismo , Sarcoidose Pulmonar/imunologia , Proteínas com Domínio T/metabolismo , Adulto Jovem
17.
Science ; 369(6504): 731-736, 2020 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-32540900

RESUMO

Broadly protective vaccines against known and preemergent human coronaviruses (HCoVs) are urgently needed. To gain a deeper understanding of cross-neutralizing antibody responses, we mined the memory B cell repertoire of a convalescent severe acute respiratory syndrome (SARS) donor and identified 200 SARS coronavirus 2 (SARS-CoV-2) binding antibodies that target multiple conserved sites on the spike (S) protein. A large proportion of the non-neutralizing antibodies display high levels of somatic hypermutation and cross-react with circulating HCoVs, suggesting recall of preexisting memory B cells elicited by prior HCoV infections. Several antibodies potently cross-neutralize SARS-CoV, SARS-CoV-2, and the bat SARS-like virus WIV1 by blocking receptor attachment and inducing S1 shedding. These antibodies represent promising candidates for therapeutic intervention and reveal a target for the rational design of pan-sarbecovirus vaccines.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Anticorpos Amplamente Neutralizantes/imunologia , Vírus da SARS/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Adulto , Idoso , Afinidade de Anticorpos , Subpopulações de Linfócitos B/imunologia , Sítios de Ligação , Reações Cruzadas , Epitopos , Feminino , Humanos , Memória Imunológica , Masculino , Pessoa de Meia-Idade , Testes de Neutralização , Peptidil Dipeptidase A/química , Peptidil Dipeptidase A/metabolismo , Domínios Proteicos , Receptores Virais/química , Receptores Virais/metabolismo , Síndrome Respiratória Aguda Grave/imunologia , Hipermutação Somática de Imunoglobulina , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/metabolismo , Adulto Jovem
18.
J Vis Exp ; (159)2020 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-32538902

RESUMO

As cell function is influenced by niche-specific factors in the cellular microenvironment, methods to dissect cell localization and migration can provide further insight on cell function. B-1a cells are a unique B cell subset in mice that produce protective natural IgM antibodies against oxidation-specific epitopes that arise during health and disease. B-1a cell IgM production differs depending on B-1a cell location, and therefore it becomes useful from a therapeutic standpoint to target B-1a localization to niches supportive of high antibody production. Here we describe a method to target B-1a cell migration to the bone marrow by retroviral-mediated overexpression of the C-X-C motif chemokine receptor 4 (CXCR4). Gene induction in primary murine B cells can be challenging and typically yields low transfection efficiencies of 10-20% depending on technique. Here we demonstrate that retroviral transduction of primary murine B-1a cells results in 30-40% transduction efficiency. This method utilizes adoptive cell transfer of transduced B-1a cells into B cell-deficient recipient mice so that donor B-1a cell migration and localization can be visualized. This protocol can be modified for other retroviral constructs and can be used in diverse functional assays post-adoptive transfer, including analysis of donor cell or host cell phenotype and function, or analysis of soluble factors secreted post B-1a cell transfer. The use of distinct donor and recipient mice differentiated by CD45.1 and CD45.2 allotype and the presence of a GFP reporter within the retroviral plasmid could also enable detection of donor cells in other, immune-sufficient mouse models containing endogenous B cell populations.


Assuntos
Transferência Adotiva , Subpopulações de Linfócitos B/imunologia , Células da Medula Óssea/imunologia , Movimento Celular , Receptores CXCR4/metabolismo , Retroviridae/metabolismo , Animais , Formação de Anticorpos , Linfócitos B/imunologia , Diferenciação Celular , Imunoglobulina M/imunologia , Antígenos Comuns de Leucócito , Camundongos , Receptores CXCR4/genética , Transdução de Sinais
19.
Science ; 369(6504): 643-650, 2020 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-32540902

RESUMO

The rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has had a large impact on global health, travel, and economy. Therefore, preventative and therapeutic measures are urgently needed. Here, we isolated monoclonal antibodies from three convalescent coronavirus disease 2019 (COVID-19) patients using a SARS-CoV-2 stabilized prefusion spike protein. These antibodies had low levels of somatic hypermutation and showed a strong enrichment in VH1-69, VH3-30-3, and VH1-24 gene usage. A subset of the antibodies was able to potently inhibit authentic SARS-CoV-2 infection at a concentration as low as 0.007 micrograms per milliliter. Competition and electron microscopy studies illustrate that the SARS-CoV-2 spike protein contains multiple distinct antigenic sites, including several receptor-binding domain (RBD) epitopes as well as non-RBD epitopes. In addition to providing guidance for vaccine design, the antibodies described here are promising candidates for COVID-19 treatment and prevention.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/imunologia , Pneumonia Viral/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Adulto , Idoso , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Afinidade de Anticorpos , Antígenos Virais/imunologia , Subpopulações de Linfócitos B/imunologia , Anticorpos Amplamente Neutralizantes/imunologia , Linhagem Celular Tumoral , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/terapia , Epitopos/imunologia , Feminino , Humanos , Memória Imunológica , Imunofenotipagem , Masculino , Pessoa de Meia-Idade , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Pneumonia Viral/terapia , Domínios Proteicos , Domínios e Motivos de Interação entre Proteínas/imunologia , Receptores Virais/metabolismo , Glicoproteína da Espícula de Coronavírus/química
20.
Immunity ; 52(5): 842-855.e6, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32353250

RESUMO

B cell subsets expressing the transcription factor T-bet are associated with humoral immune responses and autoimmunity. Here, we examined the anatomic distribution, clonal relationships, and functional properties of T-bet+ and T-bet- memory B cells (MBCs) in the context of the influenza-specific immune response. In mice, both T-bet- and T-bet+ hemagglutinin (HA)-specific B cells arose in germinal centers, acquired memory B cell markers, and persisted indefinitely. Lineage tracing and IgH repertoire analyses revealed minimal interconversion between T-bet- and T-bet+ MBCs, and parabionts showed differential tissue residency and recirculation properties. T-bet+ MBCs could be subdivided into recirculating T-betlo MBCs and spleen-resident T-bethi MBCs. Human MBCs displayed similar features. Conditional gene deletion studies revealed that T-bet expression in B cells was required for nearly all HA stalk-specific IgG2c antibodies and for durable neutralizing titers to influenza. Thus, T-bet expression distinguishes MBC subsets that have profoundly different homing, residency, and functional properties, and mediate distinct aspects of humoral immune memory.


Assuntos
Especificidade de Anticorpos/imunologia , Subpopulações de Linfócitos B/imunologia , Linfócitos B/imunologia , Memória Imunológica/imunologia , Especificidade de Órgãos/imunologia , Proteínas com Domínio T/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Subpopulações de Linfócitos B/metabolismo , Linfócitos B/metabolismo , Centro Germinativo/citologia , Centro Germinativo/imunologia , Centro Germinativo/metabolismo , Anticorpos Anti-HIV/imunologia , Humanos , Vírus da Influenza A/imunologia , Vírus da Influenza A/fisiologia , Influenza Humana/imunologia , Influenza Humana/virologia , Camundongos , Proteínas com Domínio T/genética , Proteínas com Domínio T/metabolismo
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