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1.
Proc Natl Acad Sci U S A ; 119(27): e2116896119, 2022 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-35771942

RESUMO

Throughout their evolution, plant nucleotide-binding leucine-rich-repeat receptors (NLRs) have acquired widely divergent unconventional integrated domains that enhance their ability to detect pathogen effectors. However, the functional dynamics that drive the evolution of NLRs with integrated domains (NLR-IDs) remain poorly understood. Here, we reconstructed the evolutionary history of an NLR locus prone to unconventional domain integration and experimentally tested hypotheses about the evolution of NLR-IDs. We show that the rice (Oryza sativa) NLR Pias recognizes the effector AVR-Pias of the blast fungal pathogen Magnaporthe oryzae. Pias consists of a functionally specialized NLR pair, the helper Pias-1 and the sensor Pias-2, that is allelic to the previously characterized Pia pair of NLRs: the helper RGA4 and the sensor RGA5. Remarkably, Pias-2 carries a C-terminal DUF761 domain at a similar position to the heavy metal-associated (HMA) domain of RGA5. Phylogenomic analysis showed that Pias-2/RGA5 sensor NLRs have undergone recurrent genomic recombination within the genus Oryza, resulting in up to six sequence-divergent domain integrations. Allelic NLRs with divergent functions have been maintained transspecies in different Oryza lineages to detect sequence-divergent pathogen effectors. By contrast, Pias-1 has retained its NLR helper activity throughout evolution and is capable of functioning together with the divergent sensor-NLR RGA5 to respond to AVR-Pia. These results suggest that opposite selective forces have driven the evolution of paired NLRs: highly dynamic domain integration events maintained by balancing selection for sensor NLRs, in sharp contrast to purifying selection and functional conservation of immune signaling for helper NLRs.


Assuntos
Evolução Molecular , Magnaporthe , Proteínas NLR , Oryza , Doenças das Plantas , Proteínas de Plantas , Receptores Imunológicos , Ligação Genética , Interações Hospedeiro-Patógeno/imunologia , Magnaporthe/genética , Magnaporthe/patogenicidade , Proteínas NLR/genética , Proteínas NLR/imunologia , Oryza/imunologia , Oryza/microbiologia , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Proteínas de Plantas/imunologia , Proteínas Inibidoras de STAT Ativados/genética , Proteínas Inibidoras de STAT Ativados/imunologia , Receptores Imunológicos/genética , Receptores Imunológicos/imunologia
2.
Viruses ; 12(8)2020 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-32722523

RESUMO

Flaviviruses are constantly evolving diverse immune evasion strategies, and the exploitation of the functions of suppressors of cytokine signalling (SOCS) and protein inhibitors of activated STATs (PIAS) to favour virus replication has been described for Dengue and Japanese encephalitis viruses but not for yellow fever virus (YFV), which is still of global importance despite the existence of an effective vaccine. Some mechanisms that YFV employs to evade host immune defence has been reported, but the expression patterns of SOCS and PIAS in infected cells is yet to be determined. Here, we show that SOCS1 is down-regulated early in YFV-infected HeLa and HEK 293T cells, while SOCS3 and SOCS5 are not significantly altered, and PIAS mRNA expression appears to follow a rise-dip pattern akin to circadian-controlled genes. We also demonstrate that YFV evades interferon-ß application to produce comparable viral titres. This report provides initial insight into the in vitro expression dynamics of SOCS and PIAS upon YFV infection and a basis for further investigation into SOCS/PIAS expression and how these modulate the immune response in animal models.


Assuntos
Regulação para Baixo , Proteína 1 Supressora da Sinalização de Citocina/genética , Replicação Viral/imunologia , Vírus da Febre Amarela/imunologia , Células HEK293 , Células HeLa , Humanos , Proteínas Inibidoras de STAT Ativados/genética , Proteínas Inibidoras de STAT Ativados/imunologia , Proteína 1 Supressora da Sinalização de Citocina/imunologia
3.
Oncogene ; 39(24): 4681-4694, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32398867

RESUMO

We previously identified that the development of early-stage myeloid-derived suppressor cells (eMDSCs) in breast cancer with high IL-6 (IL-6high) expression was correlated with the SOCS3 deficiency-dependent hyperactivation of the JAK/STAT signaling pathway. However, the regulatory mechanisms have not yet been elucidated. In this study, we aimed to investigate how the posttranscriptional regulation mediated by cancer exosome-derived miRNAs affected the JAK/STAT signaling pathway and the development of eMDSCs. Using miRNA microarray, we screened miR-9 and miR-181a which were exclusively upregulated in eMDSCs and inversely associated with SOCS3 expression. We found both miRNAs promoted the amplification of immature eMDSCs with the strong suppression on T-cell immunity in mice and humans. Furthermore, miR-9 and miR-181a promoted 4T1 tumor growth and immune escape via enhancing eMDSCs infiltration in situ. But miR-9 and miR-181a stimulated eMDSCs development by separately inhibiting SOCS3 and PIAS3, two crucial regulators in the negative feedback loop of the JAK/STAT signaling pathway. Elevated miR-9 and miR-181a in eMDSCs was derived from tumor-derived exosomes, and blocking the exosome release could fully attenuate the miRNA-mediated regulation on eMDSCs development. In summary, our findings indicated that tumor exosome-derived miR-9 and miR-181a activated the JAK/STAT signaling pathway via targeting SOCS3 and PIAS3, respectively, and thus promoted the expansion of eMDSCs which might provide potential therapeutic target for IL-6high breast cancer treatment.


Assuntos
Neoplasias da Mama/imunologia , Exossomos/imunologia , Neoplasias Mamárias Experimentais/imunologia , MicroRNAs/imunologia , Chaperonas Moleculares/imunologia , Células Supressoras Mieloides/imunologia , Proteínas Inibidoras de STAT Ativados/imunologia , Proteína 3 Supressora da Sinalização de Citocinas/imunologia , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Exossomos/genética , Exossomos/patologia , Feminino , Humanos , Neoplasias Mamárias Experimentais/genética , Neoplasias Mamárias Experimentais/patologia , Camundongos , Camundongos Endogâmicos BALB C , MicroRNAs/genética , Chaperonas Moleculares/genética , Células Supressoras Mieloides/patologia , Proteínas Inibidoras de STAT Ativados/genética , Proteína 3 Supressora da Sinalização de Citocinas/genética
4.
Fish Shellfish Immunol ; 94: 417-426, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31491531

RESUMO

Protein inhibitor of activated STAT (PIAS) plays a critical role in the feedback modulation of the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway as a negative regulator in mammals and Drosophila, but the function of PIAS in crustaceans is still unclear. In this study, a PIAS termed LvPIAS was cloned and characterized from Litopenaeus vannamei. The full length of LvPIAS was 3065 bp, including a 2361 bp open reading frame (ORF) coding for a protein of 786 aa. LvPIAS expression was most abundant in muscle and could respond to the challenge of LPS, Vibrio parahaemolyticus, Staphhylococcus aureus, Poly I: C and white spot syndrome virus (WSSV). LvPIAS could be induced by the transcription factor LvSTAT, but LvPIAS could inhibit the transcriptional activity of LvSTAT to the LvPIAS promoter conversely, which indicated that there was a negative feedback loop between LvSTAT and LvPIAS. Furthermore, RNAi-mediated knockdown of LvPIAS shrimps showed higher survival rate to WSSV infection than those in the control group (dsGFP injection), suggesting that LvPIAS may play a negatively role against WSSV infection.


Assuntos
Regulação da Expressão Gênica/imunologia , Imunidade Inata/genética , Penaeidae/genética , Penaeidae/imunologia , Proteínas Inibidoras de STAT Ativados/genética , Proteínas Inibidoras de STAT Ativados/imunologia , Sequência de Aminoácidos , Animais , Proteínas de Artrópodes/química , Proteínas de Artrópodes/genética , Proteínas de Artrópodes/imunologia , Sequência de Bases , Perfilação da Expressão Gênica , Lipopolissacarídeos/farmacologia , Filogenia , Poli I-C/farmacologia , Proteínas Inibidoras de STAT Ativados/química , Alinhamento de Sequência , Staphylococcus aureus/fisiologia , Vibrio parahaemolyticus/fisiologia , Vírus da Síndrome da Mancha Branca 1/fisiologia
5.
Front Immunol ; 10: 314, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30873169

RESUMO

The SUMO modification system plays an important role in T cell activation, yet how sumoylation regulates TCR-proximal signaling remains largely unknown. We show here that Phospholipase C-γ1 (PLC-γ1) is conjugated by SUMO1 at K54 and K987 upon TCR stimulation and that K54 sumoylation is pivotal for PLC-γ1-mediated T cell activation. We further demonstrate that TCR-induced K54 sumoylation of PLC-γ1 significantly promotes the formation of PLC-γ1 microclusters and the association of PLC-γ1 with the adaptor proteins SLP76 and Gads, but only slightly affects the phosphorylation of PLC-γ1 on Y783, which determines the enzyme catalytic activity. Moreover, upon TCR stimulation, the SUMO E3 ligases PIASxß and PIAS3 both interact with PLC-γ1 and cooperate to sumoylate PLC-γ1, facilitating the assembly of PLC-γ1 microclusters. Together, our findings reveal a critical role of PLC-γ1 K54 sumoylation in PLC-γ1 microcluster assembly that controls PLC-γ1-mediated T cell activation, suggesting that sumoylation may have an important role in the microcluster assembly of TCR-proximal signaling proteins.


Assuntos
Chaperonas Moleculares/imunologia , Fosfolipase C gama/imunologia , Proteínas Inibidoras de STAT Ativados/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Ubiquitina-Proteína Ligases/imunologia , Linhagem Celular , Humanos , Fosfolipase C gama/genética , Sumoilação , Linfócitos T/imunologia
6.
J Immunol ; 201(2): 451-464, 2018 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-29848755

RESUMO

The ability of cells to induce the appropriate transcriptional response to inflammatory stimuli is crucial for the timely induction of host defense mechanisms. Although a role for tumor suppressor p14ARF (ARF) in the innate immune response was previously demonstrated, the underlying mechanism is still unclear. ARF is a potent upregulator of protein SUMOylation; however, no association of this function with the immune system has been made. In this study, we show the unique role of ARF in IFN-γ-induced immune response using human cell lines. Through a systematic search of proteins SUMOylated by ARF, we identified PIAS1, an inhibitor of IFN-activated transcription factor STAT1, as a novel ARF-binding partner and SUMOylation target. In response to IFN-γ treatment, ARF promoted PIAS1 SUMOylation to inhibit the ability of PIAS1 to attenuate IFN-γ response. Wild-type, but not ARF mutants unable to enhance PIAS1 SUMOylation, prevented the PIAS1-mediated inhibition of IFN-γ response. Conversely, the SUMO-deconjugase SENP1 deSUMOylated PIAS1 to reactivate PIAS1 that was inhibited by ARF. These findings suggest that PIAS1 function is negatively modulated by SUMO modification and that SUMOylation by ARF is required to inhibit PIAS1 activity and restore IFN-γ-induced transcription. In the presence of ARF, in which case PIAS1 is inhibited, depletion of PIAS1 did not have an additive effect on IFN-γ response, suggesting that ARF-mediated enhancement of IFN-γ response is mainly due to PIAS1 inhibition. Our findings reveal a novel function of ARF to inhibit PIAS1 by enhancing SUMOylation to promote the robust induction of IFN-γ response.


Assuntos
Imunidade Inata/imunologia , Interferon gama/imunologia , Proteínas Inibidoras de STAT Ativados/imunologia , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/imunologia , Sumoilação/imunologia , Proteína Supressora de Tumor p14ARF/imunologia , Linhagem Celular , Linhagem Celular Tumoral , Células HEK293 , Humanos , Inflamação/imunologia , Fator de Transcrição STAT1/imunologia , Transcrição Gênica/imunologia , Regulação para Cima/imunologia
7.
Immunopharmacol Immunotoxicol ; 38(5): 334-43, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27324722

RESUMO

Constitutive activation of signal transducer and activator of transcription 3 (STAT3) is frequently observed and closely linked with proliferation, survival, metastasis and angiogenesis of various cancer cells, and thus its inhibition can be considered a potential therapeutic strategy. We found that 3-formylchromone (3FC) inhibited both constitutive and inducible STAT3 activation in multiple myeloma (MM) cells. Besides the inhibition of STAT3 phosphorylation, 3FC also abrogated constitutive activity and nuclear translocation of STAT3. This suppression was mediated through the inhibition of phosphorylation of Janus-activated kinase (JAK) 1/2 and Src. Furthermore, 3FC induced the expression of the protein inhibitors of activated STAT3 (PIAS3), and gene silencing of the PIAS3 by small interfering RNA abolished the ability of 3FC to inhibit STAT3 activation, suggesting a critical role for PIAS3 in the action of 3FC. 3FC also downregulated the expression of STAT3-regulated gene products such as Bcl-2, Bcl-xl, Mcl-1, Survivin, inhibitor of apoptosis protein-1 (IAP-1), Cyclin D1, cyclooxygenase-2 (COX-2), and matrix metalloproteinases-9 (MMP-9) in MM cells. This correlated with induction of substantial apoptosis as indicated by an increase in the sub-G1 cell population and caspase-3 induced poly ADP ribose polymerase (PARP) cleavage. Overall, these results suggest that 3FC is a novel blocker of STAT3 activation pathway thus may have a potential in therapy of MM and other cancers.


Assuntos
Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Cromonas/farmacologia , Chaperonas Moleculares/imunologia , Mieloma Múltiplo/imunologia , Proteínas de Neoplasias/imunologia , Proteínas Inibidoras de STAT Ativados/imunologia , Fator de Transcrição STAT3/imunologia , Transdução de Sinais/efeitos dos fármacos , Apoptose/imunologia , Linhagem Celular Tumoral , Humanos , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/patologia , Transdução de Sinais/imunologia
8.
J Immunol ; 195(3): 982-93, 2015 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-26136427

RESUMO

Many members of the BTB-ZF family have been shown to play important roles in lymphocyte development and function. The role of zinc finger Znf131 (also known as Zbtb35) in T cell lineage was elucidated through the production of mice with floxed allele to disrupt at different stages of development. In this article, we present that Znf131 is critical for T cell development during double-negative to double-positive stage, with which significant cell expansion triggered by the pre-TCR signal is coupled. In mature T cells, Znf131 is required for the activation of effector genes, as well as robust proliferation induced upon TCR signal. One of the cyclin-dependent kinase inhibitors, p21(Cip1) encoded by cdkn1a gene, is one of the targets of Znf131. The regulation of T cell proliferation by Znf131 is in part attributed to its suppression on the expression of p21(Cip1).


Assuntos
Inibidor de Quinase Dependente de Ciclina p21/genética , Proteínas de Ligação a DNA/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Linfócitos T/imunologia , Fatores de Transcrição/imunologia , Células 3T3 , Animais , Diferenciação Celular/imunologia , Linhagem Celular , Proliferação de Células , Inibidor de Quinase Dependente de Ciclina p21/biossíntese , Proteínas de Ligação a DNA/genética , Ativação Linfocitária/genética , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas Nucleares/imunologia , Regiões Promotoras Genéticas/genética , Proteínas Inibidoras de STAT Ativados/imunologia , Proteínas Proto-Oncogênicas c-myb/genética , Proteínas Proto-Oncogênicas c-myb/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Linfócitos T/citologia , Fatores de Transcrição/genética , Ubiquitina-Proteína Ligases
9.
J Virol ; 88(19): 11045-55, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25008924

RESUMO

UNLABELLED: Dendritic cells (DCs) are fundamental for the initiation of immune responses and are important players in AIDS immunopathogenesis. The modulation of DC functional activities represents a strategic mechanism for HIV-1 to evade immune surveillance. Impairment of DC function may result from bystander effects of HIV-1 envelope proteins independently of direct HIV-1 infection. In this study, we report that exposure of immature monocyte-derived DCs (MDDCs) to HIV-1 R5 gp120 resulted in the CCR5-dependent production of interleukin-6 (IL-6) via mitogen-activated protein kinase (MAPK)/NF-κB pathways. IL-6 in turn activated STAT3 by an autocrine loop. Concomitantly, gp120 promoted an early activation of STAT3 that further contributed to IL-6 induction. This activation paralleled a concomitant upregulation of the STAT3 inhibitor PIAS3. Notably, STAT3/IL-6 pathway activation was not affected by the CCR5-specific ligand CCL4. These results identify STAT3 as a key signaling intermediate activated by gp120 in MDDCs and highlight the existence of a virus-induced dysregulation of the IL-6/STAT3 axis. HIV-1 gp120 signaling through STAT3 may provide an explanation for the impairment of DC function observed upon HIV exposure. IMPORTANCE: This study provides new evidence for the molecular mechanisms and signaling pathways triggered by HIV-1 gp120 in human DCs in the absence of productive infection, emphasizing a role of aberrant signaling in early virus-host interaction, contributing to viral pathogenesis. We identified STAT3 as a key component in the gp120-mediated signaling cascade involving MAPK and NF-κB components and ultimately leading to IL-6 secretion. STAT3 now is recognized as a key regulator of DC functions. Thus, the identification of this transcription factor as a signaling molecule mediating some of gp120's biological effects unveils a new mechanism by which HIV-1 may deregulate DC functions and contribute to AIDS pathogenesis.


Assuntos
Células Dendríticas/imunologia , Proteína gp120 do Envelope de HIV/imunologia , HIV-1/imunologia , Interleucina-6/imunologia , Fator de Transcrição STAT3/imunologia , Transdução de Sinais/imunologia , Comunicação Autócrina , Diferenciação Celular , Células Cultivadas , Quimiocina CCL4/genética , Quimiocina CCL4/imunologia , Células Dendríticas/virologia , Regulação da Expressão Gênica , Proteína gp120 do Envelope de HIV/genética , HIV-1/genética , Interações Hospedeiro-Patógeno , Humanos , Evasão da Resposta Imune , Interleucina-6/genética , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/imunologia , Chaperonas Moleculares/genética , Chaperonas Moleculares/imunologia , Monócitos/imunologia , Monócitos/virologia , NF-kappa B/genética , NF-kappa B/imunologia , Proteínas Inibidoras de STAT Ativados/genética , Proteínas Inibidoras de STAT Ativados/imunologia , Receptores CCR5/genética , Receptores CCR5/imunologia , Fator de Transcrição STAT3/genética
10.
J Allergy Clin Immunol ; 134(2): 460-9, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24582310

RESUMO

BACKGROUND: The involvement of mitochondrial oxidative phosphorylation (OXPHOS) in mast cell exocytosis was recently suggested by the finding that mitochondria translocate to exocytosis sites upon mast cell activation. In parallel, mitochondrial signal transducer and activator of transcription 3 (STAT3) was found to be involved in ATP production. However, the regulation of mitochondrial STAT3 function and its connection to mast cell exocytosis is unknown. OBJECTIVE: We sought to explore the role played by mitochondrial STAT3 in mast cell exocytosis. METHODS: Experiments were performed in vitro with human and mouse mast cells and rat basophilic leukemia (RBL) cells and in vivo in mice. OXPHOS activity was measured after immunologic activation. The expression of STAT3, extracellular signal-regulated kinase 1/2, and protein inhibitor of activated STAT3 in the mitochondria during mast cell activation was determined, as was the effect of STAT3 inhibition on OXPHOS activity and mast cell function. RESULTS: Here we show that mitochondrial STAT3 is essential for immunologically mediated degranulation of human and mouse mast cells and RBL cells. Additionally, in IgE-antigen-activated RBL cells, mitochondrial STAT3 was phosphorylated on serine 727 in an extracellular signal-regulated kinase 1/2-dependent manner, which was followed by induction of OXPHOS activity. Furthermore, the endogenous inhibitor of STAT3, protein inhibitor of activated STAT3, was found to inhibit OXPHOS activity in the mitochondria, resulting in inhibition of mast cell degranulation. Moreover, mice injected with Stattic, a STAT3 inhibitor, had a significant decrease in histamine secretion. CONCLUSION: These results provide the first evidence of a regulatory role for mitochondrial STAT3 in mast cell functions, and therefore mitochondrial STAT3 could serve as a new target for the manipulation of allergic diseases.


Assuntos
Imunoglobulina E/genética , Mastócitos/patologia , Fator de Transcrição STAT3/imunologia , Animais , Antígenos/imunologia , Antígenos/farmacologia , Degranulação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Óxidos S-Cíclicos/farmacologia , Dinitrofenóis/imunologia , Dinitrofenóis/farmacologia , Exocitose/efeitos dos fármacos , Regulação da Expressão Gênica , Humanos , Imunoglobulina E/imunologia , Mastócitos/efeitos dos fármacos , Mastócitos/imunologia , Camundongos , Camundongos Endogâmicos C3H , Mitocôndrias/genética , Mitocôndrias/imunologia , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/imunologia , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 1 Ativada por Mitógeno/imunologia , Proteína Quinase 3 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/imunologia , Fosforilação Oxidativa , Proteínas Inibidoras de STAT Ativados/genética , Proteínas Inibidoras de STAT Ativados/imunologia , Ratos , Fator de Transcrição STAT3/antagonistas & inibidores , Fator de Transcrição STAT3/genética , Transdução de Sinais
11.
Biochem Biophys Res Commun ; 439(3): 384-9, 2013 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-23998932

RESUMO

MicroRNAs (miRNAs) are a class of small endogenous gene regulators that have been implicated in various developmental and pathological processes. However, the precise identities and functions of miRNAs involved in antitumor immunity are not yet well understood. miRNA-21 is an oncogenic miRNA that can be detected in various tumours. In this study, we report that a miRNA-21 inhibitor enhances the release of chemoattractants RANTES and IP-10 in the MCF-7 breast cancer cell line and results in increased lymphocyte migration. Thus, miRNA-21 is a potential therapeutic target for cancer immunotherapy. We further demonstrated that PIAS3, a protein inhibitor of activated STAT3, is a target of miRNA-21 in MCF-7. Thus, miRNA-21 is a novel miRNA regulating immune cell recruitment, which acts at least in part via its inhibition of PIAS3 expression and oncogenic STAT3 signalling in tumour cells.


Assuntos
Neoplasias da Mama/imunologia , Quimiocina CCL5/imunologia , Quimiocina CXCL10/imunologia , MicroRNAs/imunologia , Chaperonas Moleculares/imunologia , Proteínas Inibidoras de STAT Ativados/imunologia , Fator de Transcrição STAT3/imunologia , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Movimento Celular , Regulação para Baixo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Linfócitos/imunologia , Linfócitos/metabolismo , MicroRNAs/genética , Chaperonas Moleculares/genética , Proteínas Inibidoras de STAT Ativados/genética , Interferência de RNA , Transdução de Sinais
12.
J Immunol ; 188(6): 2653-68, 2012 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-22345667

RESUMO

Members of the protein inhibitor of activated STAT (PIAS) family are key regulators of various human and mammalian signaling pathways, but data on their occurrence and functions in ancient vertebrates are limited. This study characterizes for the first time to our knowledge a PIAS4 homologue (PIAS4a) from zebrafish. Structurally, this zebrafish PIAS4a (zfPIAS4a) shares a number of conserved functional domains with mammalian PIAS4 proteins, including the scaffold attachment factor A/B/acinus/PIAS box, PINIT, and RING-finger-like zinc-binding domains and a highly acidic domain in the C-terminal region. Subcellular localization analysis shows that zfPIAS4a is a nuclear-localized protein and that the C terminus of the molecule harbors strict nuclear localization signals. Functionally, zfPIAS4a expression can be dramatically induced by the stimulation of polyinosinic-polycytidylic acid and zebrafish IFN1. It acts as a critical negative regulator of the TIR domain-containing adapter inducing IFN-ß, mitochondrial antiviral signaling (MAVS), and IFN signaling pathways, and it is the first PIAS protein that plays a role in the MAVS-mediated pathway to be identified. The structure and functionality of PIAS4 seem highly conserved from zebrafish to mammals, making zebrafish an attractive model for screens designed to uncover genes involved in IFN- and inflammatory cytokine-induced signaling pathways. This study provides preliminary evidence that the PIAS regulatory mechanism already existed in fish during vertebrate evolution. It presents valuable clues for improving the understanding of not only the negative regulation of cytokine signaling in fish but also the evolutionary history of the PIAS family from fish to mammals as a whole.


Assuntos
Evolução Biológica , Proteínas Inibidoras de STAT Ativados/genética , Transdução de Sinais/fisiologia , Peixe-Zebra/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Western Blotting , Linhagem Celular , Sequência Conservada , Feminino , Humanos , Interferons/imunologia , Interferons/metabolismo , Masculino , Mitocôndrias/metabolismo , Dados de Sequência Molecular , Filogenia , Proteínas Inibidoras de STAT Ativados/imunologia , Proteínas Inibidoras de STAT Ativados/metabolismo , Estrutura Terciária de Proteína , Transfecção , Vertebrados/genética , Peixe-Zebra/imunologia , Peixe-Zebra/metabolismo
13.
PLoS Negl Trop Dis ; 5(11): e1317, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22069502

RESUMO

Malaria affects 300 million people worldwide every year and 450,000 in Brazil. In coastal areas of Brazil, the main malaria vector is Anopheles aquasalis, and Plasmodium vivax is responsible for the majority of malaria cases in the Americas. Insects possess a powerful immune system to combat infections. Three pathways control the insect immune response: Toll, IMD, and JAK-STAT. Here we analyze the immune role of the A. aquasalis JAK-STAT pathway after P. vivax infection. Three genes, the transcription factor Signal Transducers and Activators of Transcription (STAT), the regulatory Protein Inhibitors of Activated STAT (PIAS) and the Nitric Oxide Synthase enzyme (NOS) were characterized. Expression of STAT and PIAS was higher in males than females and in eggs and first instar larvae when compared to larvae and pupae. RNA levels for STAT and PIAS increased 24 and 36 hours (h) after P. vivax challenge. NOS transcription increased 36 h post infection (hpi) while this protein was already detected in some midgut epithelial cells 24 hpi. Imunocytochemistry experiments using specific antibodies showed that in non-infected insects STAT and PIAS were found mostly in the fat body, while in infected mosquitoes the proteins were found in other body tissues. The knockdown of STAT by RNAi increased the number of oocysts in the midgut of A. aquasalis. This is the first clear evidence for the involvement of a specific immune pathway in the interaction of the Brazilian malaria vector A. aquasalis with P. vivax, delineating a potential target for the future development of disease controlling strategies.


Assuntos
Anopheles/imunologia , Anopheles/parasitologia , Óxido Nítrico Sintase/biossíntese , Plasmodium vivax/imunologia , Plasmodium vivax/isolamento & purificação , Proteínas Inibidoras de STAT Ativados/biossíntese , Fatores de Transcrição STAT/biossíntese , Animais , Brasil , Feminino , Perfilação da Expressão Gênica , Técnicas de Silenciamento de Genes , Imuno-Histoquímica , Masculino , Dados de Sequência Molecular , Óxido Nítrico Sintase/imunologia , Proteínas Inibidoras de STAT Ativados/imunologia , Fatores de Transcrição STAT/imunologia , Análise de Sequência de DNA
14.
J Immunol ; 187(6): 2982-92, 2011 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-21841135

RESUMO

Miz-1 is a Broad-complex, Tramtrack and Bric-à-brac/pox virus zinc finger domain (BTB/POZ)-containing protein expressed in lymphoid precursors that can activate or repress transcription. We report in this article that mice expressing a nonfunctional Miz-1 protein lacking the BTB/POZ domain (Miz-1(ΔPOZ)) have a severe differentiation block at the pre-T cell "ß-selection" checkpoint, evident by a drastic reduction of CD4(-)CD8(-) double-negative-3 (DN3) and DN4 cell numbers. T cell-specific genes including Rag-1, Rag-2, CD3ε, pTα, and TCRß are expressed in Miz-1-deficient cells and V(D)J recombination is intact, but few DN3/DN4 cells express a surface pre-TCR. Miz-1-deficient DN3 cells are highly apoptotic and do not divide, which is consistent with enhanced expression of p53 target genes such as Cdkn1a, PUMA, and Noxa. However, neither coexpression of the antiapoptotic protein Bcl2 nor the deletion of p21(CIP1) nor the combination of both relieved Miz-1-deficient DN3/DN4 cells from their differentiation block. Only the coexpression of rearranged TCRαß and Bcl2 fully rescued Miz-1-deficient DN3/DN4 cell numbers and enabled them to differentiate into DN4TCRß(+) and double-positive cells. We propose that Miz-1 is a critical factor for the ß-selection checkpoint and is required for both the regulation of p53 target genes and proper expression of the pre-TCR to support the proliferative burst of DN3 cells during T cell development.


Assuntos
Diferenciação Celular/imunologia , Regulação da Expressão Gênica/imunologia , Genes Codificadores da Cadeia beta de Receptores de Linfócitos T , Proteínas Nucleares/imunologia , Proteínas Inibidoras de STAT Ativados/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/biossíntese , Proteína Supressora de Tumor p53/biossíntese , Animais , Ciclo Celular , Separação Celular , Citometria de Fluxo , Expressão Gênica , Immunoblotting , Camundongos , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Proteínas Nucleares/genética , Análise de Sequência com Séries de Oligonucleotídeos , Proteínas Inibidoras de STAT Ativados/genética , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Linfócitos T/citologia , Linfócitos T/imunologia , Proteína Supressora de Tumor p53/genética , Ubiquitina-Proteína Ligases
15.
Immunity ; 33(6): 917-28, 2010 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-21167753

RESUMO

B cell development requires the coordinated action of transcription factors and cytokines, in particular interleukin-7 (IL-7). We report that mice lacking the POZ (Poxvirus and zinc finger) domain of the transcription factor Miz-1 (Zbtb17(ΔPOZ/ΔPOZ)) almost entirely lacked follicular B cells, as shown by the fact that their progenitors failed to activate the Jak-Stat5 pathway and to upregulate the antiapoptotic gene Bcl2 upon IL-7 stimulation. We show that Miz-1 exerted a dual role in the interleukin-7 receptor (IL-7R) pathway by directly repressing the Janus kinase (Jak) inhibitor suppressor of cytokine signaling 1 (Socs1) and by activating Bcl2 expression. Zbtb17(ΔPOZ/ΔPOZ) (Miz-1-deficient) B cell progenitors had low expression of early B cell genes as transcription factor 3 (Tcf3) and early B cell factor 1 (Ebf1) and showed a propensity for apoptosis. Only the combined re-expression of Bcl2 and Ebf1 could reconstitute the ability of Miz-1-deficient precursors to develop into CD19(+) B cells.


Assuntos
Linfócitos B/metabolismo , Medula Óssea/patologia , Proteínas Nucleares/metabolismo , Proteínas Inibidoras de STAT Ativados/metabolismo , Receptores de Interleucina-7/metabolismo , Proteína de Morte Celular Associada a bcl/biossíntese , Animais , Linfócitos B/imunologia , Linfócitos B/patologia , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Linhagem da Célula/genética , Linhagem da Célula/imunologia , Sobrevivência Celular/genética , Células Cultivadas , Camundongos , Camundongos Mutantes , Mutação/genética , Proteínas Nucleares/genética , Proteínas Nucleares/imunologia , Proteínas Inibidoras de STAT Ativados/genética , Proteínas Inibidoras de STAT Ativados/imunologia , Receptores de Interleucina-7/genética , Receptores de Interleucina-7/imunologia , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Ubiquitina-Proteína Ligases , Proteína de Morte Celular Associada a bcl/genética , Proteína de Morte Celular Associada a bcl/imunologia
16.
Int J Mol Med ; 26(4): 619-26, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20818504

RESUMO

Our aim in this study was to investigate the changes of inflammatory response by protein inhibitor of activated signal transducer and activator of transcription 1 (PIAS1) gene silencing treatment in cerulein-stimulated AR42J cells, and relate them to changes in cell injury, thus providing evidence for developing clinical therapies. This study examined the effects of cerulein on the activity of P38 mitogen activated protein kinase (P38MAPK), c-jun NH2-terminal kinase/stress-activated protein kinase and the inflammatory mediators released by PIAS1 gene-silenced AR42J cells. Consequently, the markers including DNA ladder, cell apoptotic rat, cell cycles, levels of cell cycle and apoptotic related factors were used to determine the effects of PIAS1 gene silencing on the cerulein-induced cell injury. The results indicated that in the cerulein-stimulated PIASI silencing cells, the activity of P38MAPK was enhanced, while at the same time, the levels of inflammatory mediators such as the tumor necrosis factor-alpha, interleukin (IL)-1beta, IL-6 and matrix metallopeptidase-9, were markedly higher than those of other cerulein-stimulated cells. Thus, the cerulein-stimulated PIASI gene-silenced cells obviously increased cell arrest in the G1/M phase by increasing P21 and P27 expression, and also induced apoptosis by regulating the P53 signaling pathway. This study suggests that the down-regulation of PIAS1 is efficacious at enhancing the expression of inflammatory mediators and inducing cell injury in acute pancreatitis (AP), thus deteriorating the severity of disease. It provides evidence that PIAS1 is a potential therapeutic target for AP.


Assuntos
Ceruletídeo/imunologia , Inativação Gênica , Pâncreas/citologia , Proteínas Inibidoras de STAT Ativados/genética , Proteínas Inibidoras de STAT Ativados/imunologia , Proteínas Quinases p38 Ativadas por Mitógeno/imunologia , Animais , Apoptose , Linhagem Celular , Inflamação/genética , Inflamação/imunologia , Interleucina-6/imunologia , Proteínas Quinases JNK Ativadas por Mitógeno/imunologia , Pancreatite/genética , Pancreatite/imunologia , RNA Interferente Pequeno/genética , Ratos , Transdução de Sinais , Fator de Necrose Tumoral alfa/imunologia
17.
Trends Immunol ; 31(5): 199-204, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20181527

RESUMO

Protein inhibitor of activated STAT3 (PIAS3), the main cellular inhibitor of signal transducers and activator of transcription 3 (STAT3), has been described as a modulator of DNA binding transcription factors. The exploration of the emerging roles of PIAS3 in immune regulation is a growing and fascinating field. Recent discoveries have shed new light on the key role of PIAS3 in the regulation of transcriptional activity, and on the molecular mechanism involved. These findings suggest that the known functions of this signalling molecule are merely the "tip of the iceberg". This article reviews the challenging questions regarding the link between PIAS3 and the intracellular signalling in immune cells. Some of the known functions of PIAS3 that potentially modulate key proteins in the immune system will also be discussed.


Assuntos
Proteínas Inibidoras de STAT Ativados/imunologia , Animais , Humanos , Fator de Transcrição Associado à Microftalmia/imunologia , Fator de Transcrição Associado à Microftalmia/metabolismo , Ligação Proteica , Proteínas Inibidoras de STAT Ativados/metabolismo , Fator de Transcrição STAT3/imunologia , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Transcrição Gênica
18.
J Immunol ; 181(8): 5646-52, 2008 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-18832723

RESUMO

Efficient clearance of apoptotic cells (AC) by professional phagocytes is crucial for tissue homeostasis and resolution of inflammation. Macrophages respond to AC with an increase in antiinflammatory cytokine production but a diminished release of proinflammatory mediators. Mechanisms to explain attenuated proinflammatory cytokine formation remain elusive. We provide evidence that peroxisome proliferator-activated receptor gamma (PPARgamma) coordinates antiinflammatory responses following its activation by AC. Exposing murine RAW264.7 macrophages to AC before LPS stimulation reduced NF-kappaB transactivation and lowered target gene expression of, that is, TNF-alpha and IL-6 compared with controls. In macrophages overexpressing a dominant negative mutant of PPARgamma, NF-kappaB transactivation in response to LPS was restored, while macrophages from myeloid lineage-specific conditional PPARgamma knockout mice proved that PPARgamma transmitted an antiinflammatory response, which was delivered by AC. Expressing a PPARgamma-Delta aa32-250 deletion mutant, we observed no inhibition of NF-kappaB. Analyzing the PPARgamma domain structures within aa 32-250, we anticipated PPARgamma sumoylation in mediating the antiinflammatory effect in response to AC. Interfering with sumoylation of PPARgamma by mutating the predicted sumoylation site (K77R), or knockdown of the small ubiquitin-like modifier (SUMO) E3 ligase PIAS1 (protein inhibitor of activated STAT1), eliminated the ability of AC to suppress NF-kappaB. Chromatin immunoprecipitation analysis demonstrated that AC prevented the LPS-induced removal of nuclear receptor corepressor (NCoR) from the kappaB site within the TNF-alpha promoter. We conclude that AC induce PPARgamma sumoylation to attenuate the removal of NCoR, thereby blocking transactivation of NF-kappaB. This contributes to an antiinflammatory phenotype shift in macrophages responding to AC by lowering proinflammatory cytokine production.


Assuntos
Apoptose/imunologia , Mediadores da Inflamação/imunologia , Interleucina-6/imunologia , Lipopolissacarídeos/farmacologia , Macrófagos/imunologia , NF-kappa B/imunologia , Proteínas Nucleares/imunologia , PPAR gama/imunologia , Processamento de Proteína Pós-Traducional/imunologia , Proteínas Repressoras/imunologia , Proteína SUMO-1/imunologia , Fator de Necrose Tumoral alfa/imunologia , Sequência de Aminoácidos/genética , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Humanos , Mediadores da Inflamação/metabolismo , Interleucina-6/biossíntese , Células Jurkat , Macrófagos/metabolismo , Camundongos , Camundongos Knockout , NF-kappa B/genética , NF-kappa B/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Correpressor 1 de Receptor Nuclear , PPAR gama/genética , PPAR gama/metabolismo , Proteínas Inibidoras de STAT Ativados/genética , Proteínas Inibidoras de STAT Ativados/imunologia , Proteínas Inibidoras de STAT Ativados/metabolismo , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Estrutura Terciária de Proteína/genética , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Elementos de Resposta/genética , Elementos de Resposta/imunologia , Proteína SUMO-1/genética , Proteína SUMO-1/metabolismo , Deleção de Sequência/genética , Deleção de Sequência/imunologia , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/genética , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/imunologia , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/metabolismo , Ativação Transcricional/efeitos dos fármacos , Ativação Transcricional/genética , Ativação Transcricional/imunologia , Fator de Necrose Tumoral alfa/biossíntese , Fator de Necrose Tumoral alfa/genética
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