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1.
Anticancer Res ; 40(10): 5437-5443, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32988865

RESUMO

BACKGROUND: Neuropilin-1 (NRP1) is a receptor for vascular endothelial growth factor A (VEGFA), and has been reported to be overexpressed in several malignancies. Since angiogenesis plays an important role in pathogenesis of multiple myeloma (MM) and the role of NRP1 in MM has not been studied yet, we characterized the expression of NRP1 in this disease. MATERIALS AND METHODS: The expression level of NRP1 was measured in 140 patients newly diagnosed with MM and 28 healthy controls by flow cytometry and quantitative reverse transcriptase polymerase chain reaction. RESULTS: Expression of NRP1 was significantly reduced on plasma cells (median=2.05%) compared to that on B-cells (median=10.05%, p<0.0001) in bone marrow of patients with MM. In MM, the expression of NRP1 was high on plasmacytoid dendritic cells (median=85.85%) and low on regulatory T-cells (median=0.6%). CONCLUSION: In MM, NRP1 is regulated differentially as compared to other B-cell malignancies at both the RNA and protein level.


Assuntos
Mieloma Múltiplo/genética , Neovascularização Patológica/genética , Neuropilina-1/genética , Fator A de Crescimento do Endotélio Vascular/genética , Adulto , Linfócitos B/metabolismo , Feminino , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/sangue , Mieloma Múltiplo/patologia , Neovascularização Patológica/sangue , Neovascularização Patológica/patologia , Neuropilina-1/sangue , Transdução de Sinais/genética
2.
Int J Mol Med ; 46(4): 1266-1273, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32945352

RESUMO

The outbreak of the 2019 coronavirus disease (named, COVID­19), caused by the novel SARS­CoV­2 virus, represents a worldwide severe threat to public health. It is of the utmost importance to characterize the immune responses against the SARS­CoV­2 and the mechanisms of hyperinflammation, in order to design better therapeutic strategies for COVID­19. In the present study, a transcriptomic analysis was performed to profile the immune signatures in lung and the bronchoalveolar lavage fluid samples from COVID­19 patients and controls. Our data concordantly revealed increased humoral responses to infection. The elucidation of the host responses to SARS­CoV­2 infection may further improve our understanding of COVID­19 pathogenesis and suggest better therapeutic strategies.


Assuntos
Linfócitos B/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/imunologia , Ativação Linfocitária , Pneumonia Viral/imunologia , Transcriptoma , Linfócitos B/metabolismo , Betacoronavirus/fisiologia , Líquido da Lavagem Broncoalveolar , Infecções por Coronavirus/genética , Bases de Dados Factuais , Feminino , Regulação da Expressão Gênica , Redes Reguladoras de Genes , Interações Hospedeiro-Patógeno , Humanos , Pulmão/imunologia , Pulmão/metabolismo , Masculino , Pandemias , Pneumonia Viral/genética
4.
Gene ; 760: 145021, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32763489

RESUMO

Human B cell activating factor (TNFSF13B, BAFF) is a tumor necrosis factor superfamily member. Binding its unique receptor (TNFRSF13C, BAFF-R) mediates gene expression and cell survival in B cells via activation of NFκB pathway. Furthermore, there is data indicating a role in T cell function. A functionally inhibitory isoform (ΔBAFF) resulting from the deletion of exon 3 in the TNFSF13B pre-RNA has already been reported. However, data on the complexity of post-transcriptional regulation is scarce. Here, we report molecular cloning of nine TNFSF13B transcript variants resulting from alternative splicing of the TNFSF13B pre-mRNA including BAFFX1. This variant is characterized by a partial retention of intron 3 of the TNFSF13B gene causing the appearance of a premature stop codon. We demonstrate the expression of the corresponding BAFFX1 protein in Jurkat T cells, in ex vivo human immune cells and in human tonsillar tissue. Thereby we contribute to the understanding of TNFSF13B gene regulation and reveal that BAFF is regulated through a post-transcriptional mechanism to a greater extent than reported to date.


Assuntos
Fator Ativador de Células B/genética , Fator Ativador de Células B/imunologia , Processamento Alternativo/genética , Fator Ativador de Células B/metabolismo , Linfócitos B/metabolismo , Éxons , Expressão Gênica , Humanos , NF-kappa B/metabolismo , Isoformas de Proteínas/genética , Precursores de RNA/metabolismo , Linfócitos T/metabolismo , Fator de Necrose Tumoral alfa/genética
5.
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
6.
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
7.
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
8.
Gene ; 762: 145056, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32805313

RESUMO

BACKGROUND: Abdominal aortic aneurysm (AAA) is a disease characterized by weakening arterial wall and permanent expansion with high mortality once rupture, which was involved with immune system activation. However, owing to technical difficulties, previous research has limited the impact of one or limited immune cells on AAA. METHODS: We analyzed the composition of immune cells using the CIBERSORT algorithm through transcriptome sequencing data from patients with stable (eAAA) and ruptured aneurysms (rAAA). The whole transcriptome sequencing data, including 17 patients with ruptured AAA and 31 patients with stable AAA were downloaded from Gene Expression Omnibus (GEO, GSE98278). After normalizing and data processing, five rAAA and seventeen eAAA patients entered the follow-up analysis. We performed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis to identify several pathways that were significantly enriched in rAAA compared to eAAA tissues. RESULTS: We demonstrated that the compositions of infiltrative immune cell in eAAA and rAAA were different. Naïve B cells, both resting and activated CD4+ memory T cells were found significantly higher in ruptured AAA, while memory B cells and activated mast cells were much less in ruptured AAA than that in stable AAA. Besides, PTX3 was significantly highly expressed in rAAA, which might be associated with the complement system and polarization of macrophages. Finally, differentially expressed genes and the related immune cells were mapped in a network to reveal the relationship between gene expression and infiltrative immune cells. CONCLUSION: We identified the infiltrated immune cell profile of eAAA and rAAA patients, which might be the potential target of AAA treatment.


Assuntos
Aneurisma da Aorta Abdominal/genética , Ruptura Aórtica/genética , Linfócitos B/metabolismo , Linfócitos T/metabolismo , Transcriptoma , Animais , Aneurisma da Aorta Abdominal/metabolismo , Aneurisma da Aorta Abdominal/patologia , Ruptura Aórtica/metabolismo , Ruptura Aórtica/patologia , Proteína C-Reativa/genética , Proteína C-Reativa/metabolismo , Células Dendríticas/metabolismo , Humanos , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Componente Amiloide P Sérico/genética , Componente Amiloide P Sérico/metabolismo
9.
Nature ; 584(7819): 142-147, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32612238

RESUMO

Nuclear processes, such as V(D)J recombination, are orchestrated by the three-dimensional organization of chromosomes at multiple levels, including compartments1 and topologically associated domains (TADs)2,3 consisting of chromatin loops4. TADs are formed by chromatin-loop extrusion5-7, which depends on the loop-extrusion function of the ring-shaped cohesin complex8-12. Conversely, the cohesin-release factor Wapl13,14 restricts loop extension10,15. The generation of a diverse antibody repertoire, providing humoral immunity to pathogens, requires the participation of all V genes in V(D)J recombination16, which depends on contraction of the 2.8-Mb-long immunoglobulin heavy chain (Igh) locus by Pax517,18. However, how Pax5 controls Igh contraction in pro-B cells remains unknown. Here we demonstrate that locus contraction is caused by loop extrusion across the entire Igh locus. Notably, the expression of Wapl is repressed by Pax5 specifically in pro-B and pre-B cells, facilitating extended loop extrusion by increasing the residence time of cohesin on chromatin. Pax5 mediates the transcriptional repression of Wapl through a single Pax5-binding site by recruiting the polycomb repressive complex 2 to induce bivalent chromatin at the Wapl promoter. Reduced Wapl expression causes global alterations in the chromosome architecture, indicating that the potential to recombine all V genes entails structural changes of the entire genome in pro-B cells.


Assuntos
Genes de Cadeia Pesada de Imunoglobulina/genética , Cadeias Pesadas de Imunoglobulinas/genética , Região Variável de Imunoglobulina/genética , Fator de Transcrição PAX5/metabolismo , Proteínas/genética , Proteínas Repressoras/metabolismo , Recombinação V(D)J/genética , Animais , Linfócitos B/citologia , Linfócitos B/metabolismo , Sítios de Ligação , Proteínas de Ciclo Celular/metabolismo , Montagem e Desmontagem da Cromatina , Proteínas Cromossômicas não Histona/metabolismo , Cadeias Pesadas de Imunoglobulinas/química , Região Variável de Imunoglobulina/química , Camundongos , Complexo Repressor Polycomb 2/metabolismo , Células Precursoras de Linfócitos B/citologia , Células Precursoras de Linfócitos B/metabolismo , Regiões Promotoras Genéticas/genética
10.
Nat Commun ; 11(1): 3677, 2020 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-32699279

RESUMO

Through the formation of concentration gradients, morphogens drive graded responses to extracellular signals, thereby fine-tuning cell behaviors in complex tissues. Here we show that the chemokine CXCL13 forms both soluble and immobilized gradients. Specifically, CXCL13+ follicular reticular cells form a small-world network of guidance structures, with computer simulations and optimization analysis predicting that immobilized gradients created by this network promote B cell trafficking. Consistent with this prediction, imaging analysis show that CXCL13 binds to extracellular matrix components in situ, constraining its diffusion. CXCL13 solubilization requires the protease cathepsin B that cleaves CXCL13 into a stable product. Mice lacking cathepsin B display aberrant follicular architecture, a phenotype associated with effective B cell homing to but not within lymph nodes. Our data thus suggest that reticular cells of the B cell zone generate microenvironments that shape both immobilized and soluble CXCL13 gradients.


Assuntos
Linfócitos B/imunologia , Microambiente Celular/imunologia , Quimiocina CXCL13/metabolismo , Células Dendríticas Foliculares/imunologia , Imunidade Adaptativa , Animais , Linfócitos B/citologia , Linfócitos B/metabolismo , Catepsina B/genética , Catepsina B/metabolismo , Linhagem Celular , Quimiocina CXCL13/imunologia , Simulação por Computador , Células Dendríticas Foliculares/citologia , Células Dendríticas Foliculares/metabolismo , Matriz Extracelular/metabolismo , Humanos , Camundongos , Camundongos Knockout , Microscopia de Fluorescência , Modelos Biológicos , Tonsila Palatina/citologia , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , Células Estromais/imunologia , Células Estromais/metabolismo
11.
Proc Natl Acad Sci U S A ; 117(30): 17957-17964, 2020 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-32661157

RESUMO

There is a need for improved influenza vaccines. In this study we compared the antibody responses in humans after vaccination with an AS03-adjuvanted versus nonadjuvanted H5N1 avian influenza virus inactivated vaccine. Healthy young adults received two doses of either formulation 3 wk apart. We found that AS03 significantly enhanced H5 hemagglutinin (HA)-specific plasmablast and antibody responses compared to the nonadjuvanted vaccine. Plasmablast response after the first immunization was exclusively directed to the conserved HA stem region and came from memory B cells. Monoclonal antibodies (mAbs) derived from these plasmablasts had high levels of somatic hypermutation (SHM) and recognized the HA stem region of multiple influenza virus subtypes. Second immunization induced a plasmablast response to the highly variable HA head region. mAbs derived from these plasmablasts exhibited minimal SHM (naive B cell origin) and largely recognized the HA head region of the immunizing H5N1 strain. Interestingly, the antibody response to H5 HA stem region was much lower after the second immunization, and this suppression was most likely due to blocking of these epitopes by stem-specific antibodies induced by the first immunization. Taken together, these findings show that an adjuvanted influenza vaccine can substantially increase antibody responses in humans by effectively recruiting preexisting memory B cells as well as naive B cells into the response. In addition, we show that high levels of preexisting antibody can have a negative effect on boosting. These findings have implications toward the development of a universal influenza vaccine.


Assuntos
Adjuvantes Imunológicos , Linfócitos B/imunologia , Reações Cruzadas/imunologia , Memória Imunológica , Virus da Influenza A Subtipo H5N1/imunologia , Vacinas contra Influenza/imunologia , Influenza Humana/prevenção & controle , Anticorpos Antivirais/imunologia , Formação de Anticorpos/imunologia , Especificidade de Anticorpos/imunologia , Linfócitos B/metabolismo , Epitopos de Linfócito B/imunologia , Feminino , Humanos , Imunização Secundária , Masculino , Plasmócitos/imunologia , Plasmócitos/metabolismo
12.
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
13.
Mol Cell Biol ; 40(18)2020 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-32631903

RESUMO

Precursor B cell acute lymphoblastic leukemia (B-ALL) is caused by genetic lesions in developing B cells that function as drivers for the accumulation of additional mutations in an evolutionary selection process. We investigated secondary drivers of leukemogenesis in a mouse model of B-ALL driven by PU.1/Spi-B deletion (Mb1-CreΔPB). Whole-exome-sequencing analysis revealed recurrent mutations in Jak3 (encoding Janus kinase 3), Jak1, and Ikzf3 (encoding Aiolos). Mutations with a high variant-allele frequency (VAF) were dominated by C→T transition mutations that were compatible with activation-induced cytidine deaminase, whereas the majority of mutations, with a low VAF, were dominated by C→A transversions associated with 8-oxoguanine DNA damage caused by reactive oxygen species (ROS). The Janus kinase (JAK) inhibitor ruxolitinib delayed leukemia onset, reduced ROS and ROS-induced gene expression signatures, and altered ROS-induced mutational signatures. These results reveal that JAK mutations can alter the course of leukemia clonal evolution through ROS-induced DNA damage.


Assuntos
Dano ao DNA , Janus Quinase 1/genética , Janus Quinase 1/metabolismo , Leucemia de Células B/metabolismo , Animais , Linfócitos B/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Janus Quinase 3/metabolismo , Leucemia de Células B/genética , Leucemia de Células B/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutação , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-ets/genética , Proteínas Proto-Oncogênicas c-ets/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transativadores/genética , Transativadores/metabolismo
14.
Nat Commun ; 11(1): 2812, 2020 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-32499490

RESUMO

Activation-induced cytidine deaminase (AID) initiates both antibody class switch recombination (CSR) and somatic hypermutation (SHM) in antibody diversification. DNA double-strand break response (DSBR) factors promote rearrangement in CSR, while translesion synthesis (TLS) polymerases generate mutations in SHM. REV7, a component of TLS polymerase zeta, is also a downstream effector of 53BP1-RIF1 DSBR pathway. Here, we study the multi-functions of REV7 and find that REV7 is required for the B cell survival upon AID-deamination, which is independent of its roles in DSBR, G2/M transition or REV1-mediated TLS. The cell death in REV7-deficient activated B cells can be fully rescued by AID-deficiency in vivo. We further identify that REV7-depedent TLS across UNG-processed apurinic/apyrimidinic sites is required for cell survival upon AID/APOBEC deamination. This study dissects the multiple roles of Rev7 in antibody diversification, and discovers that TLS is not only required for sequence diversification but also B cell survival upon AID-initiated lesions.


Assuntos
Linfócitos B/metabolismo , Citidina Desaminase/metabolismo , Quebras de DNA de Cadeia Dupla , Ativação Linfocitária , Proteínas Mad2/metabolismo , Mutação , Animais , Linfócitos B/imunologia , Sobrevivência Celular , Análise Mutacional de DNA , Proteínas de Ligação a DNA/metabolismo , DNA Polimerase Dirigida por DNA/metabolismo , Feminino , Genótipo , Switching de Imunoglobulina , Masculino , Camundongos , Recombinação Genética , Hipermutação Somática de Imunoglobulina , Uracila-DNA Glicosidase/genética
15.
Nat Commun ; 11(1): 2856, 2020 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-32503977

RESUMO

Type I interferon (IFN-I) and T helper 17 (TH17) drive pathology in neuromyelitis optica spectrum disorder (NMOSD) and in TH17-induced experimental autoimmune encephalomyelitis (TH17-EAE). This is paradoxical because the prevalent theory is that IFN-I inhibits TH17 function. Here we report that a cascade involving IFN-I, IL-6 and B cells promotes TH17-mediated neuro-autoimmunity. In NMOSD, elevated IFN-I signatures, IL-6 and IL-17 are associated with severe disability. Furthermore, IL-6 and IL-17 levels are lower in patients on anti-CD20 therapy. In mice, IFN-I elevates IL-6 and exacerbates TH17-EAE. Strikingly, IL-6 blockade attenuates disease only in mice treated with IFN-I. By contrast, B-cell-deficiency attenuates TH17-EAE in the presence or absence of IFN-I treatment. Finally, IFN-I stimulates B cells to produce IL-6 to drive pathogenic TH17 differentiation in vitro. Our data thus provide an explanation for the paradox surrounding IFN-I and TH17 in neuro-autoimmunity, and may have utility in predicting therapeutic response in NMOSD.


Assuntos
Encefalomielite Autoimune Experimental/imunologia , Interferon Tipo I/imunologia , Neuromielite Óptica/imunologia , Células Th17/imunologia , Adulto , Animais , Autoimunidade , Linfócitos B/imunologia , Linfócitos B/metabolismo , Encefalomielite Autoimune Experimental/genética , Feminino , Perfilação da Expressão Gênica , Humanos , Interleucina-17/imunologia , Interleucina-17/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Masculino , Camundongos , Pessoa de Meia-Idade , Neuromielite Óptica/genética , Proteômica
16.
Anticancer Res ; 40(6): 3147-3153, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32487609

RESUMO

BACKGROUND/AIM: Few studies have evaluated the role of miRNAs in pediatric acute lymphoblastic leukemia (ALL) relapse and a consensus of a clinically significant miRNA signature is yet to be identified. In this study, we evaluated miRNAs associated with pediatric B-ALL early relapse in two independent sample sets. MATERIALS AND METHODS: We performed global miRNA profiling on diagnostic bone marrow specimens from six early relapse (≤3 years after diagnosis) and six age- and cytogenetics-matched prolonged remission (≥4 years) patients (first set) and an independent set of 14 early relapse and 14 matched prolonged remission specimens (second set). RESULTS: Twelve and 39 top differentially expressed miRNAs were observed in the first and second sets, respectively; however, there was no overlap between the top candidates. In post-hoc analyses six miRNAs (miR-101-3p, miR-4774-5p, miR-1324, miR-631, miR-4699-5p and miR-922) among the top candidates in the second, but not the first set, were consistently upregulated in early relapse compared to remission specimens in both first (fold change=1.13-2.19, q<0.38) and second (fold change=1.48-4.78, all q<0.05) sets. Four (miR-631, mir-101-3p, miR-922 and miR-1324) of these miRNAs have been previously implicated in key functional oncogenic pathways in adult cancers. CONCLUSION: This study suggests that six candidate miRNAs, not previously implicated in pediatric ALL, are associated with early relapse in pediatric B-ALL. Validation and investigation of mechanistic roles of these miRNAs in a larger cohort are warranted, so that they may be used as prognostic markers for early relapse of pediatric B-ALL.


Assuntos
Linfócitos B/metabolismo , MicroRNAs/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Recidiva
17.
Nat Commun ; 11(1): 3013, 2020 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-32541654

RESUMO

B lymphoid development is initiated by the differentiation of hematopoietic stem cells into lineage committed progenitors, ultimately generating mature B cells. This highly regulated process generates clonal immunological diversity via recombination of immunoglobulin V, D and J gene segments. While several transcription factors that control B cell development and V(D)J recombination have been defined, how these processes are initiated and coordinated into a precise regulatory network remains poorly understood. Here, we show that the transcription factor ETS Related Gene (Erg) is essential for early B lymphoid differentiation. Erg initiates a transcriptional network involving the B cell lineage defining genes, Ebf1 and Pax5, which directly promotes expression of key genes involved in V(D)J recombination and formation of the B cell receptor. Complementation of Erg deficiency with a productively rearranged immunoglobulin gene rescued B lineage development, demonstrating that Erg is an essential and stage-specific regulator of the gene regulatory network controlling B lymphopoiesis.


Assuntos
Linfócitos B/metabolismo , Diferenciação Celular/genética , Células-Tronco Hematopoéticas/metabolismo , Linfopoese/genética , Proteínas Oncogênicas/genética , Transcrição Genética , Regulador Transcricional ERG/genética , Animais , Linfócitos B/citologia , Linhagem da Célula/genética , Células Cultivadas , Redes Reguladoras de Genes/genética , Células-Tronco Hematopoéticas/citologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Oncogênicas/metabolismo , Fator de Transcrição PAX5/genética , Fator de Transcrição PAX5/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Regulador Transcricional ERG/metabolismo , Recombinação V(D)J/genética
18.
Life Sci ; 256: 117921, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32526288

RESUMO

Estrogen is a hormone responsible for modulating several physiological processes such as immune response and bone homeostasis. Physiological fluctuations of estrogen concentration are one of the defining principles behind its mechanism. In cases of estrogen deficiency, such as in menopausal women, a more intense bone resorption may occur due to an increase in osteoclast activity. One of the main factors that influence osteoclast formation and response is the immune system, mainly through cytokines secreted by B and T cells. The purpose of this review is to highlight how estrogen can modulate the secretion of cytokines that can alter bone physiology, thereby establishing an axis between estrogen, immune cells, and osteoclastogenesis.


Assuntos
Linfócitos B/metabolismo , Citocinas/metabolismo , Estrogênios/metabolismo , Osteogênese/fisiologia , Linfócitos T/metabolismo , Animais , Reabsorção Óssea/metabolismo , Osso e Ossos/metabolismo , Diferenciação Celular , Citocinas/genética , Moduladores de Receptor Estrogênico/metabolismo , Feminino , Regulação da Expressão Gênica/fisiologia , Humanos , Menopausa/metabolismo , Osteoclastos/metabolismo
19.
Scand J Immunol ; 92(3): e12922, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32592188

RESUMO

Lipopolysaccharide (LPS)-responsive beige-like anchor (LRBA) protein was initially described as a monogenetic cause for common variable immune deficiency, a syndrome characterized by low levels of B cells, defects in memory B cell differentiation and hypogammaglobulinaemia. LRBA was identified as an LPS up-regulated gene in B cells, macrophages and T cells. LRBA weighs 320 kDa and has 2863 amino acids. Its sequence contains multiple domains, suggesting that LRBA can act as a scaffolding protein. It contains two putative binding sites for cAMP-dependent kinase (PKA) regulatory subunits, suggesting this protein can act as A-kinase anchor protein (AKAP); however, physical interactions involving LRBA and PKA have not been demonstrated to date, and functional roles for such interactions are unexplored. In this work, we investigated physical interactions involving LRBA with regulatory subunits of PKA in human B cell lines and primary human B cells. PKA is a holoenzyme composed of two regulatory subunits, which can be RIα, RIß, RIIα or RIIß, and two catalytic subunits, Cα or Cß. We co-immunoprecipitated LRBA using Ramos B cell lymphoma cells and observed that LRBA interacts with RIIß. Interestingly, St-Ht31, an inhibitory peptide that disrupts AKAP interactions with regulatory subunits, reduced the amount of interacting protein. Furthermore, in primary human B cells, LRBA was induced after CD40L and IL-4 stimulation, and under such activation, we found that LRBA interacts with RIIα and RIIß, suggesting that LRBA acts as an AKAP and binds RII subunits. Interestingly, we also identified that LRBA interacts with activation-induced cytidine deaminase in primary B cells, suggesting that it is involved in B cell function.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Linfócitos B/imunologia , Linfócitos B/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Ligante de CD40/metabolismo , Células Cultivadas , Proteínas Quinases Dependentes de AMP Cíclico/química , Humanos , Interleucina-4/metabolismo , Ativação Linfocitária/imunologia , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Transporte Proteico
20.
Scand J Immunol ; 92(3): e12920, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32594535

RESUMO

The maintenance of inner integrity of an organism is founded on the proper performance of two immunity branches, innate and adaptive immune responses. Recently, it became apparent that subset of splenic B cells named marginal zone B cells (MZB cells) exhibits unique developmental and functional features that bridge these two immunity branches. Strategically positioned at the site where blood and lymph are filtered, MZB cells represent a population of sentinels that rapidly proliferate and differentiate into IgM plasmablast cells when encountered with blood-borne, thymus-independent (TI) Ags. Moreover, MZB cells have intrinsic capability to induce potent CD4+ helper T cell response and cytokine production upon stimulation with soluble antigens. Due to their ability to overcome a time gap prior the establishment of the full adaptive response towards pathogens, MZB cells connect and direct innate and adaptive immunity. An additional interesting characteristic of MZB cells is capacity to function as regulatory cells in autoimmune processes. MZB cells may also contribute to the control of autoimmunity via the induction of tolerance by apoptotic cells. Importantly, in the clear association with inflammation and autoimmunity, MZB cells may transform into MALT lymphoma, representing a concurrence point for the infection, immunity and malignancy. This paper presents an insight into the complex biology of marginal zone B cells and their role in intertwining and directing innate and adaptive immune processes at the physiological and pathological level.


Assuntos
Linfócitos B/imunologia , Linfócitos B/metabolismo , Suscetibilidade a Doenças , Homeostase , Baço/imunologia , Baço/metabolismo , Imunidade Adaptativa , Animais , Microambiente Celular/imunologia , Humanos , Ativação Linfocitária/imunologia , Baço/patologia
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