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1.
Signal Transduct Target Ther ; 5(1): 221, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-33024073
2.
Mol Immunol ; 126: 143-152, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32829203

RESUMO

A viral infection is detected through germline-encoded pattern-recognition receptors (PRRs) leading to the production of interferons (IFNs) and proinflammatory cytokines. The objective of this study was to investigate the expression of retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs) in response to viral infection and the selected cytokine responses in the human term placenta. Placental villi and decidual explants were infected with human cytomegalovirus (CMV) or vesicular stomatitis virus (VSV) and cultured ex vivo to study viral infection. To evaluate DDX58 (RIG-I), IFIH1 (MDA5), and DHX58 (LGP2) expression, quantitative real-time PCR (qRT-PCR) was used. The expression of RLRs was detected by Western blotting. Cytokine and chemokine production, as well as RLR protein levels, were quantified using ELISA. The increased expression of both RIG-I and MDA5 and the enhanced secretion of IFN-ß were observed in response to VSV infection compared to mock-infected tissues. CMV infection resulted in higher transcript levels of DDX58 and IFIH1, while no changes in the cytokine production were observed. Our results indicate that RIG-I and MDA5 are specifically expressed in chorionic villi and deciduae in response to VSV infection. These findings suggest that RLRs may play a key role in pathogen recognition and the immune response against intrauterine viral transmission.


Assuntos
Proteína DEAD-box 58/metabolismo , Transmissão Vertical de Doença Infecciosa , Helicase IFIH1 Induzida por Interferon/metabolismo , Placenta/imunologia , Complicações Infecciosas na Gravidez/imunologia , Animais , Linhagem Celular , Citomegalovirus/imunologia , Feminino , Humanos , Interferon beta/imunologia , Interferon beta/metabolismo , Camundongos , Placenta/metabolismo , Placenta/virologia , Gravidez , Complicações Infecciosas na Gravidez/virologia , Terceiro Trimestre da Gravidez , RNA Helicases/metabolismo , Técnicas de Cultura de Tecidos , Vesiculovirus/imunologia
3.
Virology ; 548: 117-123, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32838932

RESUMO

The matrix (M) protein of vesicular stomatitis virus (VSV) plays a key role in immune evasion. While VSV has been thought to suppress the interferon (IFN) response primarily by inhibiting host cell transcription and translation, our recent findings indicate that the M protein also targets NF-κB activation. Therefore, the M protein may utilize two distinct mechanisms to limit expression of antiviral genes, inhibiting both host gene expression and NF-κB activation. Here we characterize a recently reported mutation in the M protein [M(D52G)] of VSV isolate 22-20, which suppressed IFN mRNA and protein production despite activating NF-κB. 22-20 inhibited reporter gene expression from multiple promoters, suggesting that 22-20 suppressed the IFN response via M-mediated inhibition of host cell transcription. We propose that suppression of the IFN response and regulation of NF-κB are independent, genetically separable functions of the VSV M protein.


Assuntos
Interferon beta/imunologia , NF-kappa B/imunologia , Estomatite Vesicular/imunologia , Vírus da Estomatite Vesicular Indiana/imunologia , Proteínas da Matriz Viral/imunologia , Animais , Linhagem Celular , Regulação da Expressão Gênica , Interações Hospedeiro-Patógeno , Humanos , Interferon beta/genética , Camundongos , NF-kappa B/genética , Estomatite Vesicular/genética , Estomatite Vesicular/virologia , Vírus da Estomatite Vesicular Indiana/genética , Vírus da Estomatite Vesicular Indiana/fisiologia , Proteínas da Matriz Viral/genética
4.
Nat Rev Immunol ; 20(10): 585-586, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32788708
5.
Proc Natl Acad Sci U S A ; 117(35): 21568-21575, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32817552

RESUMO

The DNA sensor cGMP-AMP synthase (cGAS) senses cytosolic microbial or self DNA to initiate a MITA/STING-dependent innate immune response. cGAS is regulated by various posttranslational modifications at its C-terminal catalytic domain. Whether and how its N-terminal unstructured domain is regulated by posttranslational modifications remain unknown. We identified the acetyltransferase KAT5 as a positive regulator of cGAS-mediated innate immune signaling. Overexpression of KAT5 potentiated viral-DNA-triggered transcription of downstream antiviral genes, whereas a KAT5 deficiency had the opposite effects. Mice with inactivated Kat5 exhibited lower levels of serum cytokines in response to DNA virus infection, higher viral titers in the brains, and more susceptibility to DNA-virus-induced death. Mechanistically, KAT5 catalyzed acetylation of cGAS at multiple lysine residues in its N-terminal domain, which promoted its DNA-binding ability. Our findings suggest that KAT5-mediated cGAS acetylation at its N terminus is important for efficient innate immune response to DNA virus.


Assuntos
Infecções por Vírus de DNA/imunologia , Vírus de DNA/imunologia , Lisina Acetiltransferase 5/imunologia , Nucleotidiltransferases/imunologia , Acetilação , Animais , GMP Cíclico/metabolismo , Infecções por Vírus de DNA/genética , Infecções por Vírus de DNA/metabolismo , Vírus de DNA/genética , Feminino , Células HEK293 , Células HeLa , Interações Hospedeiro-Patógeno , Humanos , Imunidade Inata , Interferon beta/imunologia , Lisina Acetiltransferase 5/genética , Lisina Acetiltransferase 5/metabolismo , Masculino , Camundongos , Camundongos Knockout , Óxido Nítrico Sintase/genética , Óxido Nítrico Sintase/metabolismo , Nucleotidiltransferases/genética , Nucleotidiltransferases/metabolismo , Processamento de Proteína Pós-Traducional , Transdução de Sinais , Proteínas Virais/metabolismo
6.
Arch Virol ; 165(10): 2249-2258, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32696270

RESUMO

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


Assuntos
Subpopulações de Linfócitos B/imunologia , Infecções por Birnaviridae/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Regulação da Expressão Gênica/imunologia , Doenças das Aves Domésticas/imunologia , Animais , Antígenos CD/genética , Antígenos CD/imunologia , Subpopulações de Linfócitos B/virologia , Infecções por Birnaviridae/genética , Infecções por Birnaviridae/patologia , Infecções por Birnaviridae/virologia , Bolsa de Fabricius/imunologia , Bolsa de Fabricius/virologia , Linfócitos T CD4-Positivos/virologia , Linfócitos T CD8-Positivos/virologia , Antígeno CTLA-4/genética , Antígeno CTLA-4/imunologia , Galinhas/virologia , Vírus da Doença Infecciosa da Bursa/crescimento & desenvolvimento , Vírus da Doença Infecciosa da Bursa/imunologia , Vírus da Doença Infecciosa da Bursa/patogenicidade , Interferon beta/genética , Interferon beta/imunologia , Interferon gama/genética , Interferon gama/imunologia , Interleucina-10/genética , Interleucina-10/imunologia , Mucosa Intestinal/imunologia , Mucosa Intestinal/virologia , Tonsila Palatina/imunologia , Tonsila Palatina/virologia , Doenças das Aves Domésticas/genética , Doenças das Aves Domésticas/patologia , Doenças das Aves Domésticas/virologia
7.
Artigo em Inglês | MEDLINE | ID: mdl-32656094

RESUMO

As an emerging swine enteropathogenic coronavirus, porcine deltacoronavirus (PDCoV) not only causes serious diarrhea in suckling piglets but also possesses the potential for cross-species transmission, which has sparked growing interest when studying this emerging virus. We previously identified a novel accessory protein NS7a encoded by PDCoV; however, the function of NS7a was not resolved. In this study, we demonstrated that PDCoV NS7a is an interferon antagonist. Overexpression of NS7a notably inhibited Sendai virus (SeV)-induced interferon-ß (IFN-ß) production and the activation of IRF3 rather than NF-κB. NS7a also inhibited IFN-ß promoter activity induced by RIG-I, MDA5, MAVS, TBK1, and IKKε, which are key components of the RIG-I-like receptor (RLR) signaling pathway but not IRF3, the transcription factor downstream of TBK1/IKKε. Surprisingly, NS7a specifically interacts with IKKε but not with the closely related TBK1. Furthermore, NS7a interacts simultaneously with the kinase domain (KD) and the scaffold dimerization domain (SDD) of IKKε, competing with TRAF3, and IRF3 for binding to IKKε, leading to the reduction of RLR-mediated IFN-ß production. The interactions of TRAF3-IKKε and IKKε-IRF3 are also attenuated in PDCoV-infected cells. Taken together, our results demonstrate that PDCoV NS7a inhibits IFN-ß production by disrupting the association of IKKε with both TRAF3 and IRF3, revealing a new mechanism utilized by a PDCoV accessory protein to evade the host antiviral innate immune response.


Assuntos
Infecções por Coronavirus/metabolismo , Coronavirus/metabolismo , Quinase I-kappa B/metabolismo , Fator Regulador 3 de Interferon/metabolismo , Interferon beta/antagonistas & inibidores , Fator 3 Associado a Receptor de TNF/metabolismo , Proteínas não Estruturais Virais/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Coronavirus/genética , Coronavirus/imunologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Células HEK293 , Humanos , Quinase I-kappa B/imunologia , Evasão da Resposta Imune , Fator Regulador 3 de Interferon/imunologia , Helicase IFIH1 Induzida por Interferon/metabolismo , Interferon beta/biossíntese , Interferon beta/imunologia , Receptores do Ácido Retinoico/metabolismo , Vírus Sendai/imunologia , Vírus Sendai/metabolismo , Transdução de Sinais , Suínos , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/imunologia
8.
Nat Commun ; 11(1): 3624, 2020 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-32681036

RESUMO

TRIM family proteins play integral roles in the innate immune response to virus infection. MG53 (TRIM72) is essential for cell membrane repair and is believed to be a muscle-specific TRIM protein. Here we show human macrophages express MG53, and MG53 protein expression is reduced following virus infection. Knockdown of MG53 in macrophages leads to increases in type I interferon (IFN) upon infection. MG53 knockout mice infected with influenza virus show comparable influenza virus titres to wild type mice, but display increased morbidity accompanied by more accumulation of CD45+ cells and elevation of IFNß in the lung. We find that MG53 knockdown results in activation of NFκB signalling, which is linked to an increase in intracellular calcium oscillation mediated by ryanodine receptor (RyR). MG53 inhibits IFNß induction in an RyR-dependent manner. This study establishes MG53 as a new target for control of virus-induced morbidity and tissue injury.


Assuntos
Influenza Humana/imunologia , Interferon beta/metabolismo , Proteínas de Membrana/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Proteínas com Motivo Tripartido/metabolismo , Animais , Sinalização do Cálcio/imunologia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Técnicas de Silenciamento de Genes , Técnicas de Inativação de Genes , Humanos , Imunidade Inata , Vírus da Influenza A Subtipo H1N1/imunologia , Influenza Humana/virologia , Interferon beta/imunologia , Macrófagos/imunologia , Macrófagos/metabolismo , Masculino , Proteínas de Membrana/genética , Camundongos , Camundongos Knockout , NF-kappa B/metabolismo , RNA Interferente Pequeno , Transdução de Sinais/imunologia , Proteínas com Motivo Tripartido/genética
9.
Mol Immunol ; 125: 178-186, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32717666

RESUMO

PM2.5, a major component of air pollutants, has caused severe health problems. It has been reported that PM2.5 index is closely associated with severity of influenza A virus (IAV) infection. However, the underlying mechanisms have not been addressed. NLRP3 inflammasome and type I interferon signaling regulate host defense against influenza infection. The present study investigated the potential effects of air pollutants on host defense against influenza infection in vitro and in vivo. In this study, different concentrations of PM2.5 were pre-exposed to macrophages and mice before IAV infection to assess the negative effects of air pollutants in virus infection. We found that exposure to PM2.5 deteriorated influenza virus infection via compromising innate immune responses manifested by a decrease IL-1ß and IFN-ß production in vitro. Meanwhile, mice exposed with PM2.5 were susceptible to PR8 virus infection due to down-regulation of IL-1ß and IFN-ß. Mechanistically, PM 2.5 exposure suppressed the NLRP3 inflammasome activation and the AHR-TIPARP signaling pathway, by which compromised the anti-influenza immunity. Thus, our study revealed that PM2.5 could alter macrophage inflammatory responses by suppressing LPS-induced activation of NLRP3 inflammasome and expression of IFN-ß during influenza infection. These findings provided us new insights in understanding that PM2.5 combining with influenza infection could enhance the severity of pneumonia.


Assuntos
Poluentes Atmosféricos/toxicidade , Inflamassomos/efeitos dos fármacos , Interferon beta/biossíntese , Proteína 3 que Contém Domínio de Pirina da Família NLR/efeitos dos fármacos , Infecções por Orthomyxoviridae/imunologia , Material Particulado/toxicidade , Animais , Inflamassomos/imunologia , Inflamassomos/metabolismo , Vírus da Influenza A Subtipo H1N1 , Interferon beta/imunologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Infecções por Orthomyxoviridae/metabolismo
12.
Virus Res ; 286: 198074, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32589897

RESUMO

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel human coronavirus causing the pandemic of severe pneumonia (Coronavirus Disease 2019, COVID-19). SARS-CoV-2 is highly pathogenic in human, having posed immeasurable public health challenges to the world. Innate immune response is critical for the host defense against viral infection and the dysregulation of the host innate immune responses probably aggravates SARS-CoV-2 infection, contributing to the high morbidity and lethality of COVID-19. It has been reported that some coronavirus proteins play an important role in modulating innate immunity of the host, but few studies have been conducted on SARS-CoV-2. In this study, we screened the viral proteins of SARS-CoV-2 and found that the viral ORF6, ORF8 and nucleocapsid proteins were potential inhibitors of type I interferon signaling pathway, a key component for antiviral response of host innate immune. All the three proteins showed strong inhibition on type I interferon (IFN-ß) and NF-κB-responsive promoter, further examination revealed that these proteins were able to inhibit the interferon-stimulated response element (ISRE) after infection with Sendai virus, while only ORF6 and ORF8 proteins were able to inhibit the ISRE after treatment with interferon beta. These findings would be helpful for the further study of the detailed signaling pathway and unveil the key molecular player that may be targeted.


Assuntos
Betacoronavirus/genética , Interações Hospedeiro-Patógeno/genética , Interferon beta/genética , NF-kappa B/genética , Proteínas do Nucleocapsídeo/genética , Proteínas Virais/genética , Betacoronavirus/imunologia , Regulação da Expressão Gênica , Genes Reporter , Células HEK293 , Interações Hospedeiro-Patógeno/imunologia , Humanos , Imunidade Inata , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/imunologia , Interferon beta/imunologia , Luciferases/genética , Luciferases/metabolismo , NF-kappa B/imunologia , Proteínas do Nucleocapsídeo/imunologia , Plasmídeos/química , Plasmídeos/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Elementos de Resposta , Vírus Sendai/genética , Vírus Sendai/imunologia , Transdução de Sinais , Transfecção/métodos , Proteínas Virais/imunologia
13.
Arch Virol ; 165(7): 1557-1567, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32356187

RESUMO

Caprine arthritis-encephalitis (CAE) is a chronic progressive infectious disease caused by caprine arthritis-encephalitis virus (CAEV) that seriously threatens the goat industry. Chronic infection and life-long multi-tissue inflammation are the typical features of the disease. Innate antiviral immunity is essential for the host defense system that rapidly recognizes and eliminates invading viruses. Interferon ß (IFN-ß) is important for innate immunity and regulates immunity against a broad spectrum of viruses. To investigate the details of the IFN-ß response to CAEV infection, the effects of six viral proteins and the molecular mechanisms by which they affect IFN-ß production were analyzed. Overexpression of DU and Vif promote virus proliferation and inhibit the production of IFN-ß. qRT-PCR and luciferase reporter assays showed that overexpression of Vif inhibits the expression of luciferase under the control of the ISRE, NF-κB or IFN-ß promoter but does not affect the expression of IFN-ß activated by IRF3, indicating that Vif negatively regulates IFN-ß production by affecting upstream signal transduction of IRF3. Amino acids 149-164 of Vif were found to be necessary for the inhibitory effect of IFN-ß production. Our results indicate that CAEV evades surveillance and clearance by intracellular innate immunity by downregulating IFN-ß production.


Assuntos
Vírus da Artrite-Encefalite Caprina/imunologia , Produtos do Gene vif/imunologia , Doenças das Cabras/imunologia , Interferon beta/imunologia , Infecções por Lentivirus/veterinária , Animais , Vírus da Artrite-Encefalite Caprina/genética , Produtos do Gene vif/genética , Doenças das Cabras/genética , Doenças das Cabras/virologia , Cabras , Interações Hospedeiro-Patógeno , Imunidade Inata , Interferon beta/genética , Infecções por Lentivirus/genética , Infecções por Lentivirus/imunologia , Infecções por Lentivirus/virologia , NF-kappa B/genética , NF-kappa B/imunologia
14.
Physiol Genomics ; 52(5): 217-221, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: covidwho-47305
15.
Physiol Genomics ; 52(5): 217-221, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32275178
16.
Mol Immunol ; 121: 195-203, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32298923

RESUMO

Cells recognize virus nucleic acid by pattern recognition receptors (PRRs), virus involve in the activation of signaling cascade of variable adaptor proteins, TANK-binding kinase1(TBK1)/ inhibitor of nuclear factor kappa-B kinase subunit epsilon(IKKi) complex, IκB kinase(IKKs) to trigger activation of transcription factor, interferon regulatory factor 3/7(IRF3/7), ultimately, leading to the production of type I interferon and exert anti-viral effects. In this study, E3 ubiquitin ligase ankyrin repeat and SOCS box-containing 8(ASB8) interacted with TBK1/IKKi and phosphorylation modification of ASB8 at site of Ser17 to further strengthen its ubiquitination activity were verified. Conversely, phosphorylated ASB8 accelerate K48-linked ubiquitination and degradation of TBK1/IKKi, which further reduces phosphorylation level of IRF3 and inhibits production of IFN-ß. At the same time, a new bridge molecule Leucine-rich repeat containing protein 10B(LRRC10B) upregulated after viral infection are involved in the formation and interaction with ASB8-TBK1/IKKi complex was reported. Our study reveals a new mechanism of ubiquitin ligase ASB8 modulating antiviral innate immunity by altering stability of TBK1/IKKi kinase complex.


Assuntos
Quinase I-kappa B/metabolismo , Interferon beta/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Supressoras da Sinalização de Citocina/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Células HEK293 , Células HeLa , Humanos , Quinase I-kappa B/imunologia , Imunidade Inata , Fator Regulador 3 de Interferon/metabolismo , Fator Regulador 7 de Interferon/metabolismo , Interferon beta/imunologia , Fosforilação/imunologia , Proteínas Serina-Treonina Quinases/imunologia , RNA Interferente Pequeno/metabolismo , Serina/metabolismo , Transdução de Sinais/imunologia , Proteínas Supressoras da Sinalização de Citocina/genética , Proteínas Supressoras da Sinalização de Citocina/imunologia , Ubiquitina-Proteína Ligases/imunologia , Ubiquitinação/imunologia
17.
Immunity ; 52(4): 668-682.e7, 2020 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-32294407

RESUMO

The primary mechanisms supporting immunoregulatory polarization of myeloid cells upon infiltration into tumors remain largely unexplored. Elucidation of these signals could enable better strategies to restore protective anti-tumor immunity. Here, we investigated the role of the intrinsic activation of the PKR-like endoplasmic reticulum (ER) kinase (PERK) in the immunoinhibitory actions of tumor-associated myeloid-derived suppressor cells (tumor-MDSCs). PERK signaling increased in tumor-MDSCs, and its deletion transformed MDSCs into myeloid cells that activated CD8+ T cell-mediated immunity against cancer. Tumor-MDSCs lacking PERK exhibited disrupted NRF2-driven antioxidant capacity and impaired mitochondrial respiratory homeostasis. Moreover, reduced NRF2 signaling in PERK-deficient MDSCs elicited cytosolic mitochondrial DNA elevation and, consequently, STING-dependent expression of anti-tumor type I interferon. Reactivation of NRF2 signaling, conditional deletion of STING, or blockade of type I interferon receptor I restored the immunoinhibitory potential of PERK-ablated MDSCs. Our findings demonstrate the pivotal role of PERK in tumor-MDSC functionality and unveil strategies to reprogram immunosuppressive myelopoiesis in tumors to boost cancer immunotherapy.


Assuntos
Carcinoma Pulmonar de Lewis/imunologia , Carcinoma Epitelial do Ovário/imunologia , Regulação Neoplásica da Expressão Gênica , Melanoma Experimental/imunologia , Proteínas de Membrana/imunologia , Neoplasias Cutâneas/imunologia , eIF-2 Quinase/imunologia , Animais , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Carcinoma Pulmonar de Lewis/genética , Carcinoma Pulmonar de Lewis/metabolismo , Carcinoma Pulmonar de Lewis/patologia , Carcinoma Epitelial do Ovário/genética , Carcinoma Epitelial do Ovário/metabolismo , Carcinoma Epitelial do Ovário/patologia , Feminino , Humanos , Imunossupressão , Interferon-alfa/genética , Interferon-alfa/imunologia , Interferon beta/genética , Interferon beta/imunologia , Masculino , Melanoma Experimental/genética , Melanoma Experimental/metabolismo , Melanoma Experimental/patologia , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/imunologia , Mitocôndrias/metabolismo , Células Supressoras Mieloides/imunologia , Células Supressoras Mieloides/patologia , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/imunologia , Receptores de Interferon/genética , Receptores de Interferon/imunologia , Transdução de Sinais , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Resposta a Proteínas não Dobradas/imunologia , eIF-2 Quinase/deficiência , eIF-2 Quinase/genética
18.
J Virol ; 94(11)2020 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-32238581

RESUMO

Highly pathogenic avian influenza A(H5N8) viruses first emerged in China in 2010 and in 2014 spread throughout Asia and to Europe and the United States via migrating birds. Influenza A(H5N8) viruses were first detected in the Netherlands in 2014 and caused five outbreaks in poultry farms but were infrequently detected in wild birds. In 2016, influenza A(H5N8) viruses were reintroduced into the Netherlands, resulting in eight poultry farm outbreaks. This outbreak resulted in numerous dead wild birds with severe pathology. Phylogenetic analysis showed that the polymerase genes of these viruses had undergone extensive reassortment between outbreaks. Here, we investigated the differences in virulence between the 2014-15 and the 2016-17 outbreaks by characterizing the polymerase complex of influenza A(H5N8) viruses from both outbreaks. We found that viruses from the 2014-15 outbreak had significantly higher polymerase complex activity in both human and avian cell lines than did those from the 2016-17 outbreak. No apparent differences in the balance between transcription and replication of the viral genome were observed. Interestingly, the 2014-15 polymerase complexes induced significantly higher levels of interferon beta (IFN-ß) than the polymerase complexes of the 2016-17 outbreak viruses, mediated via retinoic acid-inducible gene I (RIG-I). Inoculation of primary duck cells with recombinant influenza A(H5N8) viruses, including viruses with reassorted polymerase complexes, showed that the polymerase complexes from the 2014-15 outbreak induced higher levels of IFN-ß despite relatively minor differences in replication capacity. Together, these data suggest that despite the lower levels of polymerase activity, the higher 2016-17 influenza A(H5N8) virus virulence may be attributed to the lower level of activation of the innate immune system.IMPORTANCE Compared to the 2014-15 outbreak, the 2016-17 outbreak of influenza A(H5N8) viruses in the Netherlands and Europe was more virulent; the number of dead or diseased wild birds found and the severity of pathological changes were higher during the 2016-17 outbreak. The polymerase complex plays an important role in influenza virus virulence, and the gene segments of influenza A(H5N8) viruses reassorted extensively between the outbreaks. In this study, the 2014-15 polymerase complexes were found to be more active, which is counterintuitive with the observed higher virulence of the 2016-17 outbreak viruses. Interestingly, the 2014-15 polymerase complexes also induced higher levels of IFN-ß. These findings suggest that the higher virulence of influenza A(H5N8) viruses from the 2016-17 outbreak may be related to the lower induction of IFN-ß. An attenuated interferon response could lead to increased dissemination, pathology, and mortality, as observed in (wild) birds infected during the 2016-2017 outbreak.


Assuntos
Proteínas Aviárias , Surtos de Doenças , Vírus da Influenza A Subtipo H5N8 , Influenza Aviária , Interferon beta , RNA Replicase , Proteínas Virais , Animais , Proteínas Aviárias/genética , Proteínas Aviárias/imunologia , Coturnix , Cães , Patos , Células HEK293 , Humanos , Vírus da Influenza A Subtipo H5N8/genética , Vírus da Influenza A Subtipo H5N8/imunologia , Influenza Aviária/epidemiologia , Influenza Aviária/genética , Influenza Aviária/imunologia , Interferon beta/genética , Interferon beta/imunologia , Células Madin Darby de Rim Canino , RNA Replicase/genética , RNA Replicase/imunologia , Proteínas Virais/genética , Proteínas Virais/imunologia
19.
PLoS Pathog ; 16(3): e1008435, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32210480

RESUMO

A striking feature of human visceral leishmaniasis (VL) is chronic inflammation in the spleen and liver, and VL patients present increased production levels of multiple inflammatory mediators, which contribute to tissue damage and disease severity. Here, we combined an experimental model with the transcriptional profile of human VL to demonstrate that the TLR4-IFN-ß pathway regulates the chronic inflammatory process and is associated with the asymptomatic form of the disease. Tlr4-deficient mice harbored fewer parasites in their spleen and liver than wild-type mice. TLR4 deficiency enhanced the Th1 immune response against the parasite, which was correlated with an increased activation of dendritic cells (DCs). Gene expression analyses demonstrated that IRF1 and IFN-ß were expressed downstream of TLR4 after infection. Accordingly, IRF1- and IFNAR-deficient mice harbored fewer parasites in the target organs than wild-type mice due to having an increased Th1 immune response. However, the absence of TLR4 or IFNAR increased the serum transaminase levels in infected mice, indicating the presence of liver damage in these animals. In addition, IFN-ß limits IFN-γ production by acting directly on Th1 cells. Using RNA sequencing analysis of human samples, we demonstrated that the transcriptional signature for the TLR4 and type I IFN (IFN-I) pathways was positively modulated in asymptomatic subjects compared with VL patients and thus provide direct evidence demonstrating that the TLR4-IFN-I pathway is related to the nondevelopment of the disease. In conclusion, our results demonstrate that the TLR4-IRF1 pathway culminates in IFN-ß production as a mechanism for dampening the chronic inflammatory process and preventing immunopathology development.


Assuntos
Fator Regulador 1 de Interferon/imunologia , Interferon beta/imunologia , Leishmania infantum/imunologia , Leishmaniose Visceral/imunologia , Células Th1/imunologia , Receptor 4 Toll-Like/imunologia , Animais , Inflamação/genética , Inflamação/imunologia , Inflamação/patologia , Fator Regulador 1 de Interferon/genética , Interferon beta/genética , Leishmaniose Visceral/genética , Leishmaniose Visceral/patologia , Camundongos , Camundongos Knockout , Células Th1/patologia , Receptor 4 Toll-Like/genética
20.
Mol Immunol ; 121: 136-143, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32200171

RESUMO

The innate immune system is activated upon virus invasion of a host cell by recognizing viral component, such as dsRNA through specific receptors, resulting in the production of type- I IFNs, which confer an antiviral state within the invaded as well as surrounding cells. In the present study, fibroblast, monocyte and macrophage cells derived from water Buffalo (Bubalus bubalis) were exposed to a synthetic dsRNA analogue, poly I:C to mimic viral invasion in each cell type. Recognition of poly I:C through cytosolic helicase receptors RIG-I and MDA5 molecule lead to the activation of the RLR pathway, subsequently activating the MAVS-IRF3/7 cascade and the production of antiviral effector molecule like IFNß and ISGs. Within the different cell types, we identified variability in RLR receptor and IFNß expression after poly I:C administration. Fibroblasts responded quickly and strongly with IFNß production, followed by macrophages and monocytes. Despite absolute expression variability among different cell types the expression trend of RLRs pathway genes were similar. Length of poly I:C molecule also influence IFNß expression in response of RLR pathway. Short (LMW) poly I:C induce stronger IFN-ß expression in myeloid (macrophage and monocyte) cells. In contrast long (HMW) poly I:C preferably elicit higher IFNß expression in non-myeloid (fibroblast) cell. Therefore, MDA5 and RIG-1 plays an indispensable role in eliciting antiviral response in non- immune (fibroblast) host cell. Thus, stimulation of RLR pathway with suitable and potentially cell-type specific agonist molecules successfully elicit antiviral state in the host animal, with fibroblasts conferring a stronger antiviral state compared with the monocytes and macrophages.


Assuntos
Búfalos/imunologia , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Imunidade Inata/efeitos dos fármacos , Poli I-C/farmacologia , Animais , Células Cultivadas , Proteína DEAD-box 58/imunologia , Proteína DEAD-box 58/metabolismo , Resistência à Doença/imunologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/imunologia , Fibroblastos/metabolismo , Interações Hospedeiro-Patógeno/imunologia , Interferon beta/imunologia , Interferon beta/metabolismo , Macrófagos Alveolares/efeitos dos fármacos , Macrófagos Alveolares/imunologia , Macrófagos Alveolares/metabolismo , Monócitos/efeitos dos fármacos , Monócitos/imunologia , Monócitos/metabolismo , Cultura Primária de Células , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia
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