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1.
Immunity ; 51(3): 465-478.e6, 2019 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-31422869

RESUMO

The generation of high-affinity neutralizing antibodies, the objective of most vaccine strategies, occurs in B cells within germinal centers (GCs) and requires rate-limiting "help" from follicular helper CD4+ T (Tfh) cells. Although Tfh differentiation is an attribute of MHC II-restricted CD4+ T cells, the transcription factors driving Tfh differentiation, notably Bcl6, are not restricted to CD4+ T cells. Here, we identified a requirement for the CD4+-specific transcription factor Thpok during Tfh cell differentiation, GC formation, and antibody maturation. Thpok promoted Bcl6 expression and bound to a Thpok-responsive region in the first intron of Bcl6. Thpok also promoted the expression of Bcl6-independent genes, including the transcription factor Maf, which cooperated with Bcl6 to mediate the effect of Thpok on Tfh cell differentiation. Our findings identify a transcriptional program that links the CD4+ lineage with Tfh differentiation, a limiting factor for efficient B cell responses, and suggest avenues to optimize vaccine generation.


Assuntos
Diferenciação Celular/imunologia , Proteínas Proto-Oncogênicas c-bcl-6/imunologia , Proteínas Proto-Oncogênicas c-maf/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Fatores de Transcrição/imunologia , Transcrição Genética/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Linfócitos B/imunologia , Linfócitos T CD4-Positivos/imunologia , Feminino , Regulação da Expressão Gênica/imunologia , Centro Germinativo/imunologia , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos C57BL
2.
Fish Shellfish Immunol ; 93: 612-622, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31408730

RESUMO

In teleost fish, IgM+ B cells play important roles in innate and adaptive immunity. Different IgM+ B cells are detected in teleost, named IgMlo and IgMhi B cell subsets, according to the distinct expression levels of membrane IgM (mIgM). However, the study on the heterogeneity in IgM+ B cell subsets remains poorly understood. In this study, the comparative transcriptomic profiles of IgM-, IgMlo and IgMhi from peripheral blood of Nile tilapia (Oreochromis niloticus) were carried out by using RNA-sequencing technique. A total of 6045 and 5470 differentially expressed genes (DEGs) were detected in IgMlo and IgMhi cells, respectively, as compared with IgM- lymphocytes, whereas 3835 genes were differentially expressed when IgMlo compared to IgMhi cells. Analysis of the KEGG database indicated that the DEGs were enriched in immune system categories and signaling transduction and interaction in IgM- vs IgMhi, IgM- vs IgMlo and IgMlo vs IgMhi. Comparatively, in IgMlo vs IgMhi, GO enrichment analysis indicated that the DEGs enriched in nucleic acid binding transcription factor activity. Analysis of crucial transcription factors for B cell differentiation indicated that IgMlo and IgMhi cell clusters belonged to the different B cell subsets. The data generated in this study may provide insights into understanding the heterogeneity of IgM+ cells in teleost, and suggest that IgM+ B cells play a crucial role in innate immunity.


Assuntos
Ciclídeos/genética , Ciclídeos/imunologia , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Imunidade Inata/genética , Imunoglobulina M/imunologia , Transcrição Genética/imunologia , Animais , Perfilação da Expressão Gênica/veterinária , Imunoglobulina M/genética , Leucócitos/imunologia , /veterinária
3.
Nat Commun ; 10(1): 3023, 2019 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-31289266

RESUMO

The largest gene families in eukaryotes are subject to allelic exclusion, but mechanisms underpinning single allele selection and inheritance remain unclear. Here, we describe a protein complex sustaining variant surface glycoprotein (VSG) allelic exclusion and antigenic variation in Trypanosoma brucei parasites. The VSG-exclusion-1 (VEX1) protein binds both telomeric VSG-associated chromatin and VEX2, an ortholog of nonsense-mediated-decay helicase, UPF1. VEX1 and VEX2 assemble in an RNA polymerase-I transcription-dependent manner and sustain the active, subtelomeric VSG-associated transcription compartment. VSG transcripts and VSG coats become highly heterogeneous when VEX proteins are depleted. Further, the DNA replication-associated chromatin assembly factor, CAF-1, binds to and specifically maintains VEX1 compartmentalisation following DNA replication. Thus, the VEX-complex controls VSG-exclusion, while CAF-1 sustains VEX-complex inheritance in association with the active-VSG. Notably, the VEX2-orthologue and CAF-1 in mammals are also implicated in exclusion and inheritance functions. In trypanosomes, these factors sustain a highly effective and paradigmatic immune evasion strategy.


Assuntos
Variação Antigênica/genética , Epigênese Genética/imunologia , Proteínas de Protozoários/genética , Trypanosoma brucei brucei/genética , Glicoproteínas Variantes de Superfície de Trypanosoma/genética , Alelos , Animais , Variação Antigênica/imunologia , Linhagem Celular , Fator 1 de Modelagem da Cromatina/imunologia , Fator 1 de Modelagem da Cromatina/metabolismo , Replicação do DNA/imunologia , Regulação da Expressão Gênica/imunologia , Interações Hospedeiro-Parasita/genética , Interações Hospedeiro-Parasita/imunologia , Evasão da Resposta Imune , Proteínas de Protozoários/imunologia , Transcrição Genética/imunologia , Trypanosoma brucei brucei/imunologia , Tripanossomíase Africana/imunologia , Tripanossomíase Africana/parasitologia , Glicoproteínas Variantes de Superfície de Trypanosoma/imunologia , Glicoproteínas Variantes de Superfície de Trypanosoma/metabolismo
4.
BMC Med Genomics ; 12(1): 66, 2019 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-31118097

RESUMO

BACKGROUND: In cystic fibrosis (CF), impaired immune cell responses, driven by the dysfunctional CF transmembrane conductance regulator (CFTR) gene, may determine the disease severity but clinical heterogeneity remains a major therapeutic challenge. The characterization of molecular mechanisms underlying impaired immune responses in CF may reveal novel targets with therapeutic potential. Therefore, we utilized simultaneous RNA sequencing targeted at identifying differentially expressed genes, transcripts, and miRNAs that characterize impaired immune responses triggered by CF and its phenotypes. METHODS: Peripheral blood mononuclear cells (PBMCs) extracted from a healthy donor were stimulated with plasma from CF patients (n = 9) and healthy controls (n = 3). The PBMCs were cultured (1 × 105 cells/well) for 9 h at 37 ° C in 5% CO2. After culture, total RNA was extracted from each sample and used for simultaneous total RNA and miRNA sequencing. RESULTS: Analysis of expression signatures from peripheral blood mononuclear cells induced by plasma of CF patients and healthy controls identified 151 genes, 154 individual transcripts, and 41 miRNAs differentially expressed in CF compared to HC while the expression signatures of 285 genes, 241 individual transcripts, and seven miRNAs differed due to CF phenotypes. Top immune pathways influenced by CF included agranulocyte adhesion, diapedesis signaling, and IL17 signaling, while those influenced by CF phenotypes included natural killer cell signaling and PI3K signaling in B lymphocytes. Upstream regulator analysis indicated dysregulation of CCL5, NF-κB and IL1A due to CF while dysregulation of TREM1 and TP53 regulators were associated with CF phenotype. Five miRNAs showed inverse expression patterns with three target genes relevant in CF-associated impaired immune pathways while two miRNAs showed inverse expression patterns with two target genes relevant to a dysregulated immune pathway associated with CF phenotypes. CONCLUSIONS: Our results indicate that miRNAs and individual transcript variants are relevant molecular targets contributing to impaired immune cell responses in CF.


Assuntos
Fibrose Cística/genética , Fibrose Cística/imunologia , Análise de Sequência de RNA , Transcrição Genética/imunologia , Adolescente , Estudos de Casos e Controles , Criança , Fibrose Cística/sangue , Feminino , Perfilação da Expressão Gênica , Humanos , Masculino , MicroRNAs/genética , Fenótipo
5.
Fish Shellfish Immunol ; 91: 188-193, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31077849

RESUMO

Columnaris disease has long been recognized as a serious problem worldwide which affects both wild and cultured freshwater fish including the commercially important channel catfish (Ictalurus punctatus). The fundamental molecular mechanisms of the host immune response to the causative agent Flavobacterium columnare remain unclear, though gene expression analysis after the bacterial infection has been conducted. Alternative splicing, a post-transcriptional regulation process to modulate gene expression and increase the proteomic diversity, has not yet been studied in channel catfish following infection with F. columnare. In this study, genomic information and RNA-Seq datasets of channel catfish were used to characterize the changes of alternative splicing after the infection. Alternative splicing was shown to be induced by F. columnare infection, with 8.0% increase in alternative splicing event at early infection stage. Intriguingly, genes involved in RNA binding and RNA splicing themselves were significantly enriched in differentially alternatively spliced (DAS) gene sets after infection. This finding was consistent with our previous study in channel catfish following infection with Edwardsiella ictaluri. It was suggested to be a universal mechanism that genes involved in RNA binding and splicing were regulated to undergo differential alternative splicing after stresses in channel catfish. Moreover, many immune genes were observed to be differentially alternatively spliced after infection. Further studies need to be performed to get a deeper view of molecular regulation on alternative splicing after stresses, setting a foundation for developing catfish broodstocks with enhanced disease resistance.


Assuntos
Processamento Alternativo/imunologia , Doenças dos Peixes/imunologia , Infecções por Flavobacteriaceae/veterinária , Ictaluridae , Transcrição Genética/imunologia , Animais , Doenças dos Peixes/microbiologia , Infecções por Flavobacteriaceae/imunologia , Infecções por Flavobacteriaceae/microbiologia , Flavobacterium/fisiologia , Distribuição Aleatória
6.
Mol Immunol ; 112: 115-122, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31082645

RESUMO

Mycobacterium tuberculosis (M. tuberculosis) persistent infection might cause the dysfunction of hematopoiesis. To investigate whether M. tuberculosis persistent antigen stimulation impairs the proliferation and differentiation of hematopoietic stem and progenitor cells characterized as lineage- c-Kit+ (LK cells), C57BL/6 mice were primed with Mycobacterium bovis Bacillus Calmette-Guérin (BCG) and boosted with a cocktail of M. tuberculosis antigens ESAT6, CFP10 and Mtb10.4-HspX (MH) along with adjuvant N, N'-dimethyl-N, N'-dioctadecylammonium bromide (DDA) plus polyinosinic-polycytidylic acid (Poly I:C) weekly for 12 or 22 weeks. The cytokine production by splenic T cells, proliferation of LK cells and transcriptional events during differentiation of bone marrow (BM) c-Kit+ cells were investigated. Meanwhile, the mice were treated with interleukin 2 (IL-2) and the therapeutic effects were analyzed. We found that antigen specific interferon-γ (IFN-γ) production by splenic CD4+ T cells increased following antigen stimulation for 12 weeks, but it declined after continuous stimulation for 22 weeks. The long-term exposure of mice to M. tuberculosis antigen compromised the proliferation of LK cells. Moreover, the expression of transcription factors in the c-Kit+ cells was adjusted, with up-regulation of IRF8 and Batf2 involved in myeloid differentiation and down-regulation of NOTCH1 and GATA2 participated in T-cell lineage commitment. The concentrations of IFN-γ in BM of the persistent antigen group were higher than that in sham control at the 12th week, while the concentrations of IL-2 in BM of the persistent antigen group were lower compared with the transient antigen stimulation control. Following IL-2 treatment, the concentrations of IL-2 in BM increased while IFN-γ got declined. IL-2 treatment could restore the expression levels of those transcription factors and the proliferating activity of LK cells impaired by persistent antigen stimulation. Our results indicate that M. tuberculosis antigen persistent stimulation decreases the proliferating activity of LK cells, promotes myelopoietic differentiation, and represses lymphopoietic differentiation as a consequence of elevated IFN-γ production. IL-2 supplementation contributes to maintaining the homeostasis of hemopoiesis.


Assuntos
Antígenos de Bactérias/imunologia , Medula Óssea/imunologia , Proliferação de Células/fisiologia , Mycobacterium tuberculosis/imunologia , Transcrição Genética/imunologia , Adjuvantes Imunológicos/farmacologia , Animais , Anticorpos Antibacterianos/imunologia , Proteínas de Bactérias/imunologia , Medula Óssea/microbiologia , Linfócitos T CD4-Positivos/imunologia , Diferenciação Celular/imunologia , Feminino , Transplante de Células-Tronco Hematopoéticas/métodos , Interferon gama/imunologia , Interleucina-2/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Mycobacterium bovis/imunologia , Fatores de Transcrição/imunologia
7.
Mol Immunol ; 112: 10-21, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31075558

RESUMO

Extracellular adenosine triphosphate (eATP), released following inflammatory stimulation or infection, is a potent signaling molecule in activating innate immune responses in fish. However, the regulation of eATP-mediated innate immunity in fish remains unknown. Ecto-nucleoside triphosphate diphosphohydrolase 1 (CD39) is a critical molecular switch for controlling the ATP levels in the extracellular space. CD39 plays a key role in regulating eATP-activated innate immune responses through the phosphohydrolysis of pro-inflammatory eATP to inactive AMP. Here, we identified and characterized a CD39 homolog (namely, poCD39) in the Japanese flounder Paralichthys olivaceus and analyzed its regulatory role in eATP-mediated innate immunity. Real-time quantitative PCR analysis revealed that poCD39 is ubiquitously present in all tested normal tissues with dominant expression in enriched Japanese flounder head kidney macrophages (HKMs). Immune challenge experiments demonstrated that poCD39 expression was upregulated by inflammatory stimulation and Edwardsiella tarda infection. Biochemical and immunofluorescence analysis revealed that poCD39 is a functional glycosylated membrane protein for the hydrolysis of eATP. Inhibition of poCD939 activity with the ecto-NTPDase inhibitor ARL 67156 resulted in increased IL-1beta gene expression and ROS production in Japanese flounder HKMs. In contrast, overexpression of poCD39 in Japanese flounder FG-9307 cells reduced eATP-induced pro-inflammatory cytokine IL-1beta gene expression. Finally, poCD39 expression was significantly induced by eATP stimulation in the HKMs, suggesting that eATP may provide a feedback mechanism for transcriptional regulation of fish CD39. Taken together, we identified and characterized a functional fish CD39 protein involved in regulating eATP-mediated innate immune responses in fish.


Assuntos
Trifosfato de Adenosina/imunologia , Antígenos CD/imunologia , Apirase/imunologia , Linguado/imunologia , Imunidade Inata/imunologia , Monofosfato de Adenosina/imunologia , Animais , Edwardsiella tarda/imunologia , Infecções por Enterobacteriaceae/imunologia , Infecções por Enterobacteriaceae/microbiologia , Infecções por Enterobacteriaceae/veterinária , Proteínas de Peixes/imunologia , Linguado/microbiologia , Regulação da Expressão Gênica/imunologia , Rim Cefálico/imunologia , Rim Cefálico/microbiologia , Inflamação/imunologia , Inflamação/microbiologia , Japão , Macrófagos/imunologia , Macrófagos/microbiologia , Espécies Reativas de Oxigênio/imunologia , Transcrição Genética/imunologia , Regulação para Cima/imunologia
8.
Fish Shellfish Immunol ; 91: 209-215, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31112790

RESUMO

Runt related transcription factors as trans-acting elements play critical roles in the developmental control of cell fate, hematopoiesis, bone formation and cancers. In previous study, the homologue of runt related transcription factor PmRunt has been identified from pearl oyster Pinctada fucata martensii and considered to play an important role in nacre formation. In this study, we used the same samples to perform RNA-seq to detect the global effects after the decrease of PmRunt expression. The transcription levels of several nacre shell matrix protein (NSMP) genes were significantly changed and the potential compensatory effect could happen internal gene families. Downregulation of PmRunt could also influence the biosynthesis of NSMPs through affecting amino acid metabolism, translation, protein processing and export. The inhibition of PmRunt also possibly affected the expression of caspases, IAPs and C1qs that related to apoptosis and immune. In addition, PmRunt highly expressed at 12 h and 12 d after transplantation in hemolymph, which was corresponded to transplantation immunity immune response and the morphology of pearl sac, suggested the cross-talk of biomineralization-immune regulation in hemocytes. Furthermore, a lincRNA (LncRunt) that co-located with PmRunt was identified and showed a significantly relative expression with PmRunt, which suggested the potential regulation. Therefore, these findings provided new idea to find the regulation targets of runt-related transcription factors and offers evidence of lncRNAs in potential biomineralization-immune regulation.


Assuntos
Pinctada/genética , RNA Longo não Codificante/genética , Fatores de Transcrição/genética , Animais , Regulação da Expressão Gênica/imunologia , Pinctada/imunologia , Pinctada/metabolismo , RNA Longo não Codificante/metabolismo , Análise de Sequência de RNA , Fatores de Transcrição/metabolismo , Transcrição Genética/imunologia
9.
Mol Immunol ; 111: 43-52, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30959420

RESUMO

Salmonella enterica serovar Typhimurium (S. Typhimurium) changes the structure of its lipopolysaccharide (LPS) in response to the environment. The two main LPS variants found in S. Typhimurium correspond to LPS with a hepta-acylated lipid A (LPS 430) and LPS with modified phosphate groups on its lipid A (LPS 435). We have previously shown that these modified LPS have a lower capacity than wild type (WT) LPS to induce the production of pro-inflammatory cytokines in mice. Nevertheless, it is not know if LPS 430 and LPS 435 could also subvert the innate immune responses in human cells. In this study, we found that LPS 430 and LPS 435 were less efficient than WT LPS to induce the production of pro-inflammatory cytokines by human monocytes, in addition we found a decreased dimerization of the TLR4/MD-2 complex in response to LPS 430, suggesting that structurally modified LPS are sensed differently than WT LPS by this receptor; however, LPS 430 and 435 induced similar activation of the transcription factors NF-κB p65, IRF3, p38 and ERK1/2 than WT LPS. Microarray analysis of LPS 430- and LPS 435-activated monocytes revealed a gene transcription profile with differences only in the expression levels of microRNA genes compared to the profile induced by WT LPS, suggesting that the lipid A modifications present in LPS 430 and LPS 435 have a moderate effect on the activation of the human TLR4/MD-2 complex. Our results are relevant to understand LPS modulation of immune responses and this knowledge could be useful for the development of novel adjuvants and immunomodulators.


Assuntos
Citocinas/imunologia , Inflamação/imunologia , Lipopolissacarídeos/imunologia , Antígeno 96 de Linfócito/imunologia , Monócitos/imunologia , Salmonella typhimurium/imunologia , Receptor 4 Toll-Like/imunologia , Acilação/imunologia , Dimerização , Humanos , Inflamação/microbiologia , Lipídeo A/imunologia , Monócitos/microbiologia , Infecções por Salmonella/imunologia , Infecções por Salmonella/microbiologia , Transdução de Sinais/imunologia , Fatores de Transcrição/imunologia , Transcrição Genética/imunologia
10.
Fish Shellfish Immunol ; 89: 687-700, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31002929

RESUMO

Administration of probiotic, prebiotic or symbiotic supplemented diets boosts the antioxidant property, pro and/or anti-inflammatory cytokine gene transcription, innate-adaptive immunity, growth rate and feed digestibility with very low or no mortality in healthy and infected (both groups) in Labeo rohita against Aeromonas hydrophila is reported. The probiotic diet increased the white blood cell (WBC) count and globulin (GB) level significantly on or after 6th week whereas with the symbiotic diet the increase was noted two weeks earlier in both groups; the total protein (TP) level also increased significantly when fed with probiotic diet on weeks 6 and 8, whereas with symbiotic diet the significant increase manifested earlier at 4th week itself. The serum phagocytic activity (PA), respiratory burst activity (RBA), complement C3 (CC3) level, alternative complement pathway (ACP), lysozyme activity (LA), and immunoglobulin M (IgM) levels in head kidney (HK) leucocytes increased significantly (P < 0.05) in both groups fed with probiotic diet on weeks 6 and 8; with symbiotic diet from weeks 2-8; but with prebiotic diet only on 8th week. With probiotic diet the superoxide dismutase (SOD) and catalase (CAT) activities increased significantly (P < 0.05) on weeks 6 and 8; with symbiotic diet from weeks 4-8 but the prebiotics diet only on 8th week. However, glutathione peroxidase (GPx) activity increased significantly (P < 0.05) with probiotic diet on weeks 6 and 8 and with symbiotic diet from weeks 4-8. When healthy fish fed with any supplementation diet for a period of 30 days there was no mortality while 5%, 10%, and 10% mortality was observed in infected group fed with symbiotic, probiotic, and prebiotic supplementation diets. In head kidney (HK) leucocytes, the IL-1ß, IL-8, TNF-α, and NF-κB gene transcriptions were significantly up-regulation in both groups when fed with probiotic diet on weeks 6 and 8, symbiotic diet from weeks 4-8 while the prebiotic diet only on 8th week. The iNOS expression was up-regulation significantly in both groups fed with probiotic and symbiotic diets on weeks 6 and 8; however, with any diet, the relative IL-10 and TGF-ß gene expressions were down-regulated. The present study suggested that dietary administration of symbiotic diet elicited earlier antioxidant activity, innate-adaptive immune response, immune related cytokine gene modulation, and disease protection earlier i.e. on 4th week than with probiotic or prebiotic diets in L. rohita against A. hydrophila.


Assuntos
Antioxidantes/metabolismo , Cyprinidae/imunologia , Suplementos Nutricionais/análise , Doenças dos Peixes/imunologia , Imunidade Inata , Aeromonas hydrophila/fisiologia , Ração Animal/análise , Animais , Citocinas/genética , Citocinas/metabolismo , Dieta/veterinária , Infecções por Bactérias Gram-Negativas/imunologia , Imunidade Inata/efeitos dos fármacos , Prebióticos/administração & dosagem , Probióticos/administração & dosagem , Simbióticos/administração & dosagem , Transcrição Genética/imunologia
11.
J Immunol ; 202(8): 2460-2472, 2019 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-30877169

RESUMO

Tcrd and Tcrg display identical developmental programs that depend on the activity of the enhancers Eδ and Eγ being "on" in pre-ß-selection thymocytes to activate transcription and V(D)J recombination of the unrearranged genes and "off" in post-ß-selection CD4+CD8+ double-positive thymocytes to inhibit transcription of the rearranged genes and avoid the expression of TCR δ- and TCR γ-chains in αß T lymphocytes. Eδ and Eγ activity depends on transcription factor binding to essential Runx and Myb sites and parallels that of Notch signaling. We performed Notch gain- and loss-of-function experiments and found that Notch signaling activates Tcrd and Tcrg transcription by favoring the recruitment of RUNX1 and MYB to the enhancers. Our results suggest that the dissociation of RUNX1 and MYB from Eδ and Eγ chromatin in double-positive thymocytes, which results in enhancer inactivation, is caused by decreased Notch signaling triggered by pre-TCR signaling, thereby deciphering the molecular mechanism of Tcrd and Tcrg silencing during ß-selection. These findings reveal a novel molecular mechanism for gene regulation via Notch signaling through the recruitment of RUNX1 and MYB to enhancer chromatin during thymocyte development.


Assuntos
Subunidade alfa 2 de Fator de Ligação ao Core/imunologia , Elementos Facilitadores Genéticos/imunologia , Proteínas Proto-Oncogênicas c-myb/imunologia , Receptores Notch/imunologia , Transdução de Sinais/imunologia , Timócitos/imunologia , Transcrição Genética/imunologia , Animais , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Humanos , Células Jurkat , Camundongos , Camundongos Knockout , Proteínas Proto-Oncogênicas c-myb/genética , Receptores de Antígenos de Linfócitos T gama-delta/genética , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Receptores Notch/genética , Transdução de Sinais/genética
12.
J Biol Chem ; 294(19): 7787-7796, 2019 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-30898878

RESUMO

Platelet factor 4 (PF4) is an anti-Plasmodium component of platelets. It is expressed in megakaryocytes and released from platelets following infection with Plasmodium Innate immunity is crucial for the host anti-Plasmodium response, in which type I interferon plays an important role. Whether there is cross-talk between innate immune signaling and the production of anti-Plasmodium defense peptides is unknown. Here we demonstrate that E74, like ETS transcription factor 4 (ELF4), a type I interferon activator, can help protect the host from Plasmodium yoelii infection. Mechanically, ELF4 binds to the promoter of genes of two C-X-C chemokines, Pf4 and pro-platelet basic protein (Ppbp), initiating the transcription of these two genes, thereby enhancing PF4-mediated killing of parasites from infected erythrocytes. Elf4 -/- mice are much more susceptible to Plasmodium infection than WT littermates. The expression level of Pf4 and Ppbp in megakaryocytes from Elf4 -/- mice is much lower than in those from control animals, resulting in increased parasitemia. In conclusion, our study uncovered a distinct role of ELF4, an innate immune molecule, in host defense against malaria.


Assuntos
Quimiocinas CXC/imunologia , Proteínas de Ligação a DNA/imunologia , Malária/imunologia , Plasmodium yoelii/imunologia , Fator Plaquetário 4/imunologia , Fatores de Transcrição/imunologia , Transcrição Genética/imunologia , Animais , Quimiocinas CXC/genética , Proteínas de Ligação a DNA/genética , Malária/genética , Malária/patologia , Camundongos , Camundongos Knockout , Fator Plaquetário 4/genética , Fatores de Transcrição/genética , Transcrição Genética/genética
13.
J Immunol ; 202(8): 2229-2239, 2019 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-30833348

RESUMO

T follicular helper (Tfh) cells are a specialized T cell subset that regulates the long-lived production of highly specific Abs by B cells during the germinal center (GC) reaction. However, the transcriptional network sustaining the Tfh cell phenotype and function is still incompletely understood. In this study, we identify the transcription factor Bach2 as a central negative regulator of Tfh cells. Ectopic overexpression of Bach2 in murine Tfh cells resulted in a rapid loss of their phenotype and subsequent breakdown of the GC response. Low Bach2 expression levels are required to maintain high expression of the signature cytokine IL-21, the coinhibitory receptor TIGIT and the transcriptional repressor Bcl-6. In stark contrast to the regulatory network in GC B cells, Bach2 in Tfh cells is not coexpressed with Bcl-6 at high levels to inhibit the antagonizing factor Blimp-1, but suppresses Bcl-6 by direct binding to the promoter. These data reveal that by replacing an activating complex of Batf and Irf-4 at the Bcl-6 promoter, Bach2 regulates the transcriptional network of Tfh cells in a different way, as in GC B cells.


Assuntos
Fatores de Transcrição de Zíper de Leucina Básica , Regulação da Expressão Gênica/imunologia , Centro Germinativo/imunologia , Proteínas Proto-Oncogênicas c-bcl-6 , Linfócitos T Reguladores/imunologia , Transcrição Genética/imunologia , Animais , Fatores de Transcrição de Zíper de Leucina Básica/genética , Fatores de Transcrição de Zíper de Leucina Básica/imunologia , Centro Germinativo/citologia , Fatores Reguladores de Interferon/genética , Fatores Reguladores de Interferon/imunologia , Interleucinas/genética , Interleucinas/imunologia , Camundongos , Camundongos Knockout , Regiões Promotoras Genéticas/imunologia , Proteínas Proto-Oncogênicas c-bcl-6/genética , Proteínas Proto-Oncogênicas c-bcl-6/imunologia , Linfócitos T Reguladores/citologia
14.
Fish Shellfish Immunol ; 87: 650-658, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30753920

RESUMO

The serum IgM concentration of ballan wrasse is relatively high, estimated to approximately 13 mg/ml in adult wild fish of 800 g. The present study revealed an unusual high abundance of IgM mRNA in the gut of ballan wrasse. Initially, transcripts encoding IgM, IgT, IgD, TCRα, TCRδ and CD3ε were quantified by RT-qPCR in several tissues of wild caught fish (approx. 800 g), indicating an elevated immune activity in hindgut and an extraordinarily high expression of IgM. Subsequently, a new RT-qPCR analysis was performed on the entire intestine, cut into four different segments, of reared fish (32-100 g). The analysis indicated immune activity along the entire intestine, but not as strong as in the hindgut. Furthermore, similar to the larger fish, the relative abundance of IgM transcripts was higher in the hindgut than in kidney and spleen, although the absolute level of IgM was in general higher in the larger fish. The secreted form of IgM was completely dominant in comparison to the membrane bound form of IgM and the other analysed genes. IgM was purified from gut mucus and external mucosal surfaces by magnetic beads coated with protein A. Mucus IgM reacted with rabbit antisera raised against serum IgM and contained subunits of the same size. Regarding the elevated immune activity in the intestine it is tempting to speculate on a possible compensatory strategy in this lineage of stomach-less fish, and that natural antibodies have an important role in the first line defence.


Assuntos
Imunidade Adaptativa/genética , Proteínas de Peixes/genética , Imunoglobulinas/genética , Perciformes/genética , Perciformes/imunologia , Receptores de Antígenos de Linfócitos T/genética , Animais , Proteínas de Peixes/imunologia , Trato Gastrointestinal/metabolismo , Perfilação da Expressão Gênica/veterinária , Imunoglobulina M/genética , Imunoglobulina M/imunologia , Imunoglobulinas/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Transcrição Genética/imunologia
15.
Immunity ; 50(3): 738-750.e7, 2019 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-30770248

RESUMO

Systemic immunosuppression greatly affects the chemotherapeutic antitumor effect. Here, we showed that CD19+ extracellular vesicles (EVs) from B cells through CD39 and CD73 vesicle-incorporated proteins hydrolyzed ATP from chemotherapy-treated tumor cells into adenosine, thus impairing CD8+ T cell responses. Serum CD19+ EVs were increased in tumor-bearing mice and patients. Patients with fewer serum CD19+ EVs had a better prognosis after chemotherapy. Upregulated hypoxia-inducible factor-1α (HIF-1α) promoted B cells to release CD19+ EVs by inducing Rab27a mRNA transcription. Rab27a or HIF-1α deficiency in B cells inhibited CD19+ EV production and improved the chemotherapeutic antitumor effect. Silencing of Rab27a in B cells by inactivated Epstein-Barr viruses carrying Rab27a siRNA greatly improved chemotherapeutic efficacy in humanized immunocompromised NOD PrkdcscidIl2rg-/- mice. Thus, decreasing CD19+ EVs holds high potential to improve the chemotherapeutic antitumor effect.


Assuntos
Linfócitos B/imunologia , Linfócitos T CD8-Positivos/imunologia , Vesículas Extracelulares/imunologia , Animais , Antígenos CD19/imunologia , Linhagem Celular , Linhagem Celular Tumoral , Feminino , Células HEK293 , Herpesvirus Humano 4/imunologia , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Células NIH 3T3 , RNA Mensageiro/imunologia , Transcrição Genética/imunologia , Proteínas rab27 de Ligação ao GTP/imunologia
16.
Neurobiol Dis ; 125: 211-218, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30716470

RESUMO

BACKGROUND: Epidemiological studies suggest that the risk of neurodevelopmental disorders such as autism spectrum disorder (ASD) and schizophrenia is increased by prenatal exposure to viral or bacterial infection during pregnancy. It is still unclear how activation of the maternal immune response interacts with underlying genetic factors to influence observed ASD phenotypes. METHODS: The current study investigated how maternal immune activation (MIA) in mice impacts gene expression in the frontal cortex in adulthood, and how these molecular changes relate to deficits in cognitive flexibility and social behavior, and increases in repetitive behavior that are prevalent in ASD. Poly(I:C) (20 mg/kg) was administered to dams on E12.5 and offspring were tested for social approach behavior, repetitive grooming, and probabilistic reversal learning in adulthood (n = 8 vehicle; n = 9 Poly(I:C)). We employed next-generation high-throughput mRNA sequencing (RNA-seq) to comprehensively investigate the transcriptome profile in frontal cortex of adult offspring of Poly(I:C)-exposed dams. RESULTS: Exposure to poly(I:C) during gestation impaired probabilistic reversal learning and decreased social approach in MIA offspring compared to controls. We found long-term effects of MIA on expression of 24 genes, including genes involved in glutamatergic neurotransmission, mTOR signaling and potassium ion channel activity. Correlations between gene expression and specific behavioral measures provided insight into genes that may be responsible for ASD-like behavioral alterations. CONCLUSIONS: These findings suggest that MIA can lead to impairments in cognitive flexibility in mice similar to those exhibited in ASD individuals, and that these impairments are associated with altered gene expression in frontal cortex.


Assuntos
Lobo Frontal/imunologia , Transtornos do Neurodesenvolvimento/imunologia , Complicações Infecciosas na Gravidez/imunologia , Efeitos Tardios da Exposição Pré-Natal/imunologia , Transcrição Genética/imunologia , Animais , Comportamento Animal/fisiologia , Cognição/fisiologia , Feminino , Lobo Frontal/fisiopatologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Gravidez , Comportamento Social
17.
J Exp Med ; 216(2): 384-406, 2019 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-30674564

RESUMO

Glucocorticoids remain the most widely used immunosuppressive and anti-inflammatory drugs, yet substantial gaps exist in our understanding of glucocorticoid-mediated immunoregulation. To address this, we generated a pathway-level map of the transcriptional effects of glucocorticoids on nine primary human cell types. This analysis revealed that the response to glucocorticoids is highly cell type dependent, in terms of the individual genes and pathways affected, as well as the magnitude and direction of transcriptional regulation. Based on these data and given their importance in autoimmunity, we conducted functional studies with B cells. We found that glucocorticoids impair upstream B cell receptor and Toll-like receptor 7 signaling, reduce transcriptional output from the three immunoglobulin loci, and promote significant up-regulation of the genes encoding the immunomodulatory cytokine IL-10 and the terminal-differentiation factor BLIMP-1. These findings provide new mechanistic understanding of glucocorticoid action and emphasize the multifactorial, cell-specific effects of these drugs, with potential implications for designing more selective immunoregulatory therapies.


Assuntos
Linfócitos B/imunologia , Regulação da Expressão Gênica/efeitos dos fármacos , Glucocorticoides/farmacologia , Transdução de Sinais/efeitos dos fármacos , Transcrição Genética/efeitos dos fármacos , Regulação da Expressão Gênica/imunologia , Humanos , Interleucina-10/imunologia , Receptores de Antígenos de Linfócitos B/imunologia , Receptores de Glucocorticoides/imunologia , Transdução de Sinais/imunologia , Receptor 7 Toll-Like/imunologia , Transcrição Genética/imunologia
18.
Immunology ; 156(2): 109-110, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30632618

RESUMO

There have been considerable advances in characterization of the complexities of natural killer (NK) cell ligand recognition, activation, subsets and effector functions. The nature of the transcription factors that act to define distinctive functional programmes of NK cell subsets are now starting to be clarified as a consequence of studies in knockouts. Importantly, this is being extended to improved understanding of the nature of NK cell memory. As NK cell biology offers increasing resonance with analogous pathways in CD8 biology, some have made the case that immunology may sometimes benefit from a little less conceptual 'splitting' and a little more conceptual 'lumping.'


Assuntos
Antígenos CD8/imunologia , Células Matadoras Naturais/imunologia , Receptores Imunológicos/imunologia , Transdução de Sinais/imunologia , Transcrição Genética/imunologia , Animais , Humanos , Camundongos , Camundongos Knockout
19.
Immunology ; 156(2): 111-119, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30450565

RESUMO

Natural killer (NK) cells are highly specialized cytotoxic lymphocytes that provide protection against pathogens and malignant cells. They develop from common lymphoid progenitors via a multi-stage lineage commitment and differentiation process that gives rise to mature NK cells with potent cytotoxic functionality. Although generally considered cells of the innate immune system, recent studies have demonstrated that NK cells have the capacity to mount immune responses with features of adaptive immunity, including robust antigen-specific clonal-like expansion and the generation of long-lived memory cells that mediate enhanced recall responses. Here, we discuss specific transcription factors that have been shown to commonly and uniquely regulate NK cell development and effector and memory responses in experimental mouse models.


Assuntos
Imunidade Celular , Imunidade Inata , Memória Imunológica , Células Matadoras Naturais/imunologia , Modelos Imunológicos , Transcrição Genética/imunologia , Animais , Humanos , Camundongos
20.
J Clin Invest ; 129(1): 93-105, 2019 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-30457979

RESUMO

Vaccines are among the most effective public health tools for combating certain infectious diseases such as influenza. The role of the humoral immune system in vaccine-induced protection is widely appreciated; however, our understanding of how antibody specificities relate to B cell function remains limited due to the complexity of polyclonal antibody responses. To address this, we developed the Spec-seq framework, which allows for simultaneous monoclonal antibody (mAb) characterization and transcriptional profiling from the same single cell. Here, we present the first application of the Spec-seq framework, which we applied to human plasmablasts after influenza vaccination in order to characterize transcriptional differences governed by B cell receptor (BCR) isotype and vaccine reactivity. Our analysis did not find evidence of long-term transcriptional specialization between plasmablasts of different isotypes. However, we did find enhanced transcriptional similarity between clonally related B cells, as well as distinct transcriptional signatures ascribed by BCR vaccine recognition. These data suggest IgG and IgA vaccine-positive plasmablasts are largely similar, whereas IgA vaccine-negative cells appear to be transcriptionally distinct from conventional, terminally differentiated, antigen-induced peripheral blood plasmablasts.


Assuntos
Vacinas contra Influenza/imunologia , Plasmócitos/imunologia , Transcrição Genética/imunologia , Vacinação , Anticorpos Antivirais/imunologia , Feminino , Humanos , Imunoglobulina A/imunologia , Imunoglobulina G/imunologia , Vacinas contra Influenza/administração & dosagem , Masculino , Plasmócitos/citologia , Receptores de Antígenos de Linfócitos B/imunologia , Transcrição Genética/efeitos dos fármacos
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