RESUMO
Microglia, the resident macrophages of the central nervous system, exhibit altered gene expression in response to various neurological conditions. This study investigates the relationship between West Nile Virus infection and microglial senescence, focusing on the role of LGALS3BP, a protein implicated in both antiviral responses and aging. Using spatial transcriptomics, RNA sequencing and flow cytometry, we characterized changes in microglial gene signatures in adult and aged mice following recovery from WNV encephalitis. Additionally, we analyzed Lgals3bp expression and generated Lgals3bp-deficient mice to assess the impact on neuroinflammation and microglial phenotypes. Our results show that WNV-activated microglia share transcriptional signatures with aged microglia, including upregulation of genes involved in interferon response and inflammation. Lgals3bp was broadly expressed in the CNS and robustly upregulated during WNV infection and aging. Lgals3bp-deficient mice exhibited reduced neuroinflammation, increased homeostatic microglial numbers, and altered T cell populations without differences in virologic control or survival. These data indicate that LGALS3BP has a role in regulating neuroinflammation and microglial activation and suggest that targeting LGALS3BP might provide a potential route for mitigating neuroinflammation-related cognitive decline in aging and post-viral infections.
Assuntos
Córtex Cerebral , Glicoproteínas , Microglia , Febre do Nilo Ocidental , Vírus do Nilo Ocidental , Animais , Masculino , Camundongos , Envelhecimento/genética , Envelhecimento/metabolismo , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Senescência Celular/genética , Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microglia/metabolismo , Microglia/virologia , Microglia/patologia , Fenótipo , Febre do Nilo Ocidental/genética , Febre do Nilo Ocidental/virologia , Febre do Nilo Ocidental/patologia , Febre do Nilo Ocidental/metabolismo , Vírus do Nilo Ocidental/fisiologia , Glicoproteínas/genética , Glicoproteínas/metabolismoRESUMO
In response to viral infection, how cells balance translational shutdown to limit viral replication and the induction of antiviral components like interferons (IFNs) is not well understood. Moreover, how distinct isoforms of IFN-induced oligoadenylate synthetase 1 (OAS1) contribute to this antiviral response also requires further elucidation. Here, we show that human, but not mouse, OAS1 inhibits SARS-CoV-2 replication through its canonical enzyme activity via RNase L. In contrast, both mouse and human OAS1 protect against West Nile virus infection by a mechanism distinct from canonical RNase L activation. OAS1 binds AU-rich elements (AREs) of specific mRNAs, including IFNß. This binding leads to the sequestration of IFNß mRNA to the endomembrane regions, resulting in prolonged half-life and continued translation. Thus, OAS1 is an ARE-binding protein with two mechanisms of antiviral activity: driving inhibition of translation but also a broader, non-canonical function of protecting IFN expression from translational shutdown.
Assuntos
2',5'-Oligoadenilato Sintetase , Interferons , Oligorribonucleotídeos , Viroses , Febre do Nilo Ocidental , Animais , Humanos , Camundongos , 2',5'-Oligoadenilato Sintetase/genética , 2',5'-Oligoadenilato Sintetase/metabolismo , Nucleotídeos de Adenina , Antivirais/farmacologia , Febre do Nilo Ocidental/genética , Febre do Nilo Ocidental/metabolismo , Vírus do Nilo Ocidental/metabolismo , Vírus do Nilo Ocidental/patogenicidadeRESUMO
IMPORTANCE: Arboviruses, particularly those transmitted by mosquitoes, pose a significant threat to humans and are an increasing concern because of climate change, human activity, and expanding vector-competent populations. West Nile virus is of significant concern as the most frequent mosquito-borne disease transmitted annually within the continental United States. Here, we identify a previously uncharacterized signaling pathway that impacts West Nile virus infection, namely endothelin signaling. Additionally, we demonstrate that we can successfully translate results obtained from D. melanogaster into the more relevant human system. Our results add to the growing field of insulin-mediated antiviral immunity and identify potential biomarkers or intervention targets to better address West Nile virus infection and severe disease.
Assuntos
Endotelinas , Insulina , Febre do Nilo Ocidental , Animais , Humanos , Drosophila melanogaster/imunologia , Drosophila melanogaster/metabolismo , Drosophila melanogaster/virologia , Insulina/metabolismo , Transdução de Sinais , Febre do Nilo Ocidental/imunologia , Febre do Nilo Ocidental/metabolismo , Febre do Nilo Ocidental/virologia , Vírus do Nilo Ocidental/imunologia , Vírus do Nilo Ocidental/fisiologia , Endotelinas/imunologia , Endotelinas/metabolismoRESUMO
Tick-borne encephalitis virus and West Nile virus can cross the blood-brain barrier via hematogenous route. The attachment of a virion to the cells of a neurovascular unit, which is mediated by domain III of glycoprotein E, initiates a series of events that may aid viral entry. Thus, we sought to uncover the post-attachment biological events elicited in brain microvascular endothelial cells by domain III. RNA sequencing of cells treated with DIII of TBEV and WNV showed significant alteration in the expression of 309 and 1076 genes, respectively. Pathway analysis revealed activation of the TAM receptor pathway. Several genes that regulate tight-junction integrity were also activated, including pro-inflammatory cytokines and chemokines, cell-adhesion molecules, claudins, and matrix metalloprotease (mainly ADAM17). Results also indicate activation of a pro-apoptotic pathway. TLR2 was upregulated in both cases, but MyD88 was not. In the case of TBEV DIII, a MyD88 independent pathway was activated. Furthermore, both cases showed dramatic dysregulation of IFN and IFN-induced genes. Results strongly suggest that the virus contact to the cell surface emanates a series of events namely viral attachment and diffusion, breakdown of tight junctions, induction of virus uptake, apoptosis, reorganization of the extracellular-matrix, and activation of the innate immune system.
Assuntos
Vírus da Encefalite Transmitidos por Carrapatos , Encefalite Transmitida por Carrapatos , Febre do Nilo Ocidental , Vírus do Nilo Ocidental , Encéfalo/metabolismo , Encefalite Transmitida por Carrapatos/metabolismo , Células Endoteliais/metabolismo , Glicoproteínas/metabolismo , Humanos , Febre do Nilo Ocidental/metabolismoRESUMO
Innate immune responses to emerging RNA viruses are increasingly recognized as having significant contributions to neurologic sequelae, especially memory disorders. Using a recovery model of West Nile virus (WNV) encephalitis, we show that, while macrophages deliver the antiviral and anti-neurogenic cytokine IL-1ß during acute infection; viral recovery is associated with continued astrocyte inflammasome-mediated production of inflammatory levels of IL-1ß, which is maintained by hippocampal astrogenesis via IL-1R1 signaling in neural stem cells (NSC). Accordingly, aberrant astrogenesis is prevented in the absence of IL-1 signaling in NSC, indicating that only newly generated astrocytes exert neurotoxic effects, preventing synapse repair and promoting spatial learning deficits. Ex vivo evaluation of IL-1ß-treated adult hippocampal NSC revealed the upregulation of developmental differentiation pathways that derail adult neurogenesis in favor of astrogenesis, following viral infection. We conclude that NSC-specific IL-1 signaling within the hippocampus during viral encephalitis prevents synapse recovery and promotes spatial learning defects via altered fates of NSC progeny that maintain inflammation.
Assuntos
Encefalite Viral , Células-Tronco Neurais , Febre do Nilo Ocidental , Humanos , Inflamassomos/metabolismo , Células-Tronco Neurais/metabolismo , Neurogênese/fisiologia , Febre do Nilo Ocidental/metabolismoRESUMO
West Nile virus (WNV), re-emerging neurotropic flavivirus, can cross the blood-brain barrier (BBB) and cause fatal encephalitis and meningitis. Infection of the human brain microvascular endothelial cells (hBMECs), building blocks of the BBB, represents the pivotal step in neuroinvasion. Domain III (DIII) of the envelope (E) glycoprotein is a key receptor-binding domain, thus, it is an attractive target for anti-flavivirus strategies. Here, two combinatorial phage display peptide libraries, Ph.D.-C7C and Ph.D.-12, were panned against receptor-binding site (RBS) on DIII to isolate peptides that could block DIII. From series of pannings, nine peptides (seven 7-mer cyclic and two 12-mer linear) were selected and overexpressed in E. coli SHuffle T5. Presence of disulfide bond in 7-mer peptides was confirmed with thiol-reactive maleimide labeling. Except for linear peptide 19 (HYSWSWIAYSPG), all peptides proved to be DIII binders. Among all peptides, 4 cyclic peptides (CTKTDVHFC, CIHSSTRAC, CTYENHRTC, and CLAQSHPLC) showed significant blocking of the interaction between DIII and hBMECs, and ability to neutralize infection in cultured cells. None of these peptides showed toxic or hemolytic activity. Peptides identified in this study may serve as potential candidates for the development of novel antiviral therapeutics against WNV.
Assuntos
Encéfalo/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Proteínas do Envelope Viral/antagonistas & inibidores , Febre do Nilo Ocidental/prevenção & controle , Vírus do Nilo Ocidental/fisiologia , Sítios de Ligação , Encéfalo/metabolismo , Encéfalo/virologia , Células Cultivadas , Endotélio Vascular/metabolismo , Endotélio Vascular/virologia , Humanos , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/isolamento & purificação , Biblioteca de Peptídeos , Ligação Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/metabolismo , Febre do Nilo Ocidental/metabolismo , Febre do Nilo Ocidental/virologiaRESUMO
West Nile virus (WNV) is a Flavivirus, which can cause febrile illness in humans that may progress to encephalitis. Like any other obligate intracellular pathogens, Flaviviruses hijack cellular protein functions as a strategy for sustaining their life cycle. Many cellular proteins display globular domain known as PDZ domain that interacts with PDZ-Binding Motifs (PBM) identified in many viral proteins. Thus, cellular PDZ-containing proteins are common targets during viral infection. The non-structural protein 5 (NS5) from WNV provides both RNA cap methyltransferase and RNA polymerase activities and is involved in viral replication but its interactions with host proteins remain poorly known. In this study, we demonstrate that the C-terminal PBM of WNV NS5 recognizes several human PDZ-containing proteins using both in vitro and in cellulo high-throughput methods. Furthermore, we constructed and assayed in cell culture WNV replicons where the PBM within NS5 was mutated. Our results demonstrate that the PBM of WNV NS5 is important in WNV replication. Moreover, we show that knockdown of the PDZ-containing proteins TJP1, PARD3, ARHGAP21 or SHANK2 results in the decrease of WNV replication in cells. Altogether, our data reveal that interactions between the PBM of NS5 and PDZ-containing proteins affect West Nile virus replication.
Assuntos
Proteínas não Estruturais Virais/metabolismo , Replicação Viral , Febre do Nilo Ocidental/virologia , Vírus do Nilo Ocidental/fisiologia , Animais , Sítios de Ligação , Linhagem Celular , Células HEK293 , Humanos , Domínios PDZ , Proteínas não Estruturais Virais/química , Febre do Nilo Ocidental/metabolismoRESUMO
Infection by malaria parasites triggers dynamic immune responses leading to diverse symptoms and pathologies; however, the molecular mechanisms responsible for these reactions are largely unknown. We performed Trans-species Expression Quantitative Trait Locus analysis to identify a large number of host genes that respond to malaria parasite infections. Here we functionally characterize one of the host genes called receptor transporter protein 4 (RTP4) in responses to malaria parasite and virus infections. RTP4 is induced by type I IFN (IFN-I) and binds to the TANK-binding kinase (TBK1) complex where it negatively regulates TBK1 signaling by interfering with expression and phosphorylation of both TBK1 and IFN regulatory factor 3. Rtp4-/- mice were generated and infected with malaria parasite Plasmodiun berghei ANKA. Significantly higher levels of IFN-I response in microglia, lower parasitemia, fewer neurologic symptoms, and better survival rates were observed in Rtp4-/- than in wild-type mice. Similarly, RTP4 deficiency significantly reduced West Nile virus titers in the brain, but not in the heart and the spleen, of infected mice, suggesting a specific role for RTP4 in brain infection and pathology. This study reveals functions of RTP4 in IFN-I response and a potential target for therapy in diseases with neuropathology.
Assuntos
Encéfalo/patologia , Interferon Tipo I/metabolismo , Malária Cerebral/patologia , Chaperonas Moleculares/metabolismo , Animais , Encéfalo/parasitologia , Encéfalo/virologia , Células HEK293 , Interações Hospedeiro-Patógeno , Humanos , Fator Regulador 3 de Interferon , Malária Cerebral/metabolismo , Malária Cerebral/parasitologia , Proteínas de Membrana , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microglia/metabolismo , Chaperonas Moleculares/genética , Fosforilação , Plasmodium berghei/fisiologia , Plasmodium yoelii/fisiologia , Ligação Proteica , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Febre do Nilo Ocidental/metabolismo , Febre do Nilo Ocidental/patologia , Febre do Nilo Ocidental/virologia , Vírus do Nilo Ocidental/fisiologiaRESUMO
Neurotropic flavivirus Japanese encephalitis virus (JEV) and West Nile virus (WNV) are amongst the leading causes of encephalitis. Using label-free quantitative proteomics, we identified proteins differentially expressed upon JEV (gp-3, RP9) or WNV (IS98) infection of human neuroblastoma cells. Data are available via ProteomeXchange with identifier PXD016805. Both viruses were associated with the up-regulation of immune response (IFIT1/3/5, ISG15, OAS, STAT1, IRF9) and the down-regulation of SSBP2 and PAM, involved in gene expression and in neuropeptide amidation respectively. Proteins associated to membranes, involved in extracellular matrix organization and collagen metabolism represented major clusters down-regulated by JEV and WNV. Moreover, transcription regulation and mRNA processing clusters were also heavily regulated by both viruses. The proteome of neuroblastoma cells infected by JEV or WNV was significantly modulated in the presence of mosquito saliva, but distinct patterns were associated to each virus. Mosquito saliva favored modulation of proteins associated with gene regulation in JEV infected neuroblastoma cells while modulation of proteins associated with protein maturation, signal transduction and ion transporters was found in WNV infected neuroblastoma cells.
Assuntos
Culicidae/metabolismo , Encefalite Japonesa/metabolismo , Neurônios/patologia , Proteoma/metabolismo , Febre do Nilo Ocidental/metabolismo , Animais , Linhagem Celular Tumoral , Culicidae/virologia , Vírus da Encefalite Japonesa (Subgrupo)/isolamento & purificação , Encefalite Japonesa/patologia , Encefalite Japonesa/virologia , Feminino , Humanos , Neurônios/metabolismo , Neurônios/virologia , Proteoma/análise , Saliva/metabolismo , Saliva/virologia , Febre do Nilo Ocidental/patologia , Febre do Nilo Ocidental/virologia , Vírus do Nilo Ocidental/isolamento & purificaçãoRESUMO
West Nile virus (WNV) is an important cause of viral encephalitis in birds and animals, including humans. Amino acid 159 of the envelope (E) protein is reportedly implicated in the different levels of neurovirulence in mice infected with WNV NY99 or Eg101. We investigated the role of amino acid 159 of the E protein in the pathogenesis of WNV infection. We produced recombinant WNV with the structural proteins of the NY99 or Eg101 strain (NY-WT or EgCME-WT) and mutant viruses with substitutions of amino acid 159 of the E protein (NY-E-V159I or EgCME-E-I159V). The NY-WT and NY-E-V159I or EgCME-WT and EgCME-E-I159V titers in culture supernatant were similar. The mortality rate and viral titer in the brains of mice inoculated intraperitoneally with NY-WT or NY-E-V159I were also similar. In contrast, the mortality rate and viral titer in the brains of mice inoculated intracranially with EgCME-E-I159V were significantly higher than those of mice inoculated with EgCME-WT. The numbers of CD3-positive and CD8-positive T cells were greater in brains inoculated with EgCME-E-I159V than in those inoculated with EgCME-WT. Therefore, amino acid 159 of the E protein modulates the pathogenicity of WNV by affecting viral replication and T-cell infiltration in the brain.
Assuntos
Encéfalo , Linfócitos T , Proteínas do Envelope Viral , Replicação Viral , Febre do Nilo Ocidental , Vírus do Nilo Ocidental/fisiologia , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Encéfalo/virologia , Chlorocebus aethiops , Células HEK293 , Humanos , Camundongos , Linfócitos T/metabolismo , Linfócitos T/patologia , Células Vero , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/metabolismo , Febre do Nilo Ocidental/genética , Febre do Nilo Ocidental/metabolismo , Febre do Nilo Ocidental/patologiaAssuntos
Doenças Transmissíveis Importadas/diagnóstico , Doença Relacionada a Viagens , Febre do Nilo Ocidental/diagnóstico , Agamaglobulinemia/induzido quimicamente , Agamaglobulinemia/complicações , Doenças Transmissíveis Importadas/complicações , Doenças Transmissíveis Importadas/metabolismo , DNA Viral/análise , Evolução Fatal , Feminino , Humanos , Linfoma Folicular/tratamento farmacológico , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Rituximab/efeitos adversos , Análise de Sequência de DNA , Febre do Nilo Ocidental/complicações , Febre do Nilo Ocidental/metabolismoRESUMO
West Nile Virus (WNV), an emerging and re-emerging RNA virus, is the leading source of arboviral encephalitic morbidity and mortality in the United States. WNV infections are acutely controlled by innate immunity in peripheral tissues outside of the central nervous system (CNS) but WNV can evade the actions of interferon (IFN) to facilitate CNS invasion, causing encephalitis, encephalomyelitis, and death. Recent studies indicate that STimulator of INterferon Gene (STING), canonically known for initiating a type I IFN production and innate immune response to cytosolic DNA, is required for host defense against neurotropic RNA viruses. We evaluated the role of STING in host defense to control WNV infection and pathology in a murine model of infection. When challenged with WNV, STING knock out (-/-) mice displayed increased morbidity and mortality compared to wild type (WT) mice. Virologic analysis and assessment of STING activation revealed that STING signaling was not required for control of WNV in the spleen nor was WNV sufficient to mediate canonical STING activation in vitro. However, STING-/- mice exhibited a clear trend of increased viral load and virus dissemination in the CNS. We found that STING-/- mice exhibited increased and prolonged neurological signs compared to WT mice. Pathological examination revealed increased lesions, mononuclear cellular infiltration and neuronal death in the CNS of STING-/- mice, with sustained pathology after viral clearance. We found that STING was required in bone marrow derived macrophages for early control of WNV replication and innate immune activation. In vivo, STING-/- mice developed an aberrant T cell response in both the spleen and brain during WNV infection that linked with increased and sustained CNS pathology compared to WT mice. Our findings demonstrate that STING plays a critical role in immune programming for the control of neurotropic WNV infection and CNS disease.
Assuntos
Sistema Nervoso Central/imunologia , Sistema Nervoso Central/patologia , Imunidade Inata/imunologia , Proteínas de Membrana/fisiologia , Replicação Viral , Febre do Nilo Ocidental/imunologia , Vírus do Nilo Ocidental/imunologia , Animais , Sistema Nervoso Central/metabolismo , Sistema Nervoso Central/virologia , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Carga Viral , Febre do Nilo Ocidental/metabolismo , Febre do Nilo Ocidental/virologiaRESUMO
The genus Flavivirus comprises approximately 73 viruses, which share several common aspects, such as dimension, structure, nucleic acid properties, and shape in electronic microscopy. Global incidence of flavivirus infection increased dramatically over the last decades, causing large outbreaks in several areas of the world. These viruses are expanding from endemic tropical and subtropical areas to previously nonendemic areas, affecting and causing diseases in millions of individuals worldwide and posing a formidable challenge to public health in several countries. The majority of clinically significant flavivirus-associated infections are mosquito borne (arboviruses-acronym for ARthropod-BOrne VIRUSES), such as dengue, yellow fever, Japanese encephalitis, Zika, and West Nile fever. Most diseases caused by flaviviruses are asymptomatic or manifest as self-limited, mild, undifferentiated febrile diseases. In a limited number of cases, these diseases may evolve to severe inflammatory, multisystem diseases, causing high morbidity and mortality. Some flaviviruses have been consistently identified in kidney tissue and urine and have been clinically associated with kidney diseases. In this review, we will provide an overview of the epidemiology, risk factors, kidney pathology, etiopathogenesis, and outcomes of acute and chronic kidney syndromes associated with dengue, yellow fever, Zika, and West Nile virus disease.
Assuntos
Injúria Renal Aguda/epidemiologia , Dengue/epidemiologia , Insuficiência Renal Crônica/epidemiologia , Febre do Nilo Ocidental/epidemiologia , Febre Amarela/epidemiologia , Infecção por Zika virus/epidemiologia , Injúria Renal Aguda/metabolismo , Injúria Renal Aguda/patologia , Injúria Renal Aguda/virologia , Dengue/metabolismo , Dengue/patologia , Flavivirus , Infecções por Flavivirus/epidemiologia , Infecções por Flavivirus/patologia , Humanos , Mosquitos Vetores , Insuficiência Renal Crônica/metabolismo , Insuficiência Renal Crônica/patologia , Insuficiência Renal Crônica/virologia , Fatores de Risco , Febre do Nilo Ocidental/metabolismo , Febre do Nilo Ocidental/patologia , Febre Amarela/metabolismo , Febre Amarela/patologia , Infecção por Zika virus/metabolismo , Infecção por Zika virus/patologiaRESUMO
West Nile virus (WNV) infection outcomes vary among individuals, with most infections resulting in asymptomatic or mild flu-like symptoms. We previously reported an association between early cytokine production and symptom outcome following WNV infection in US blood donors. In this meta-analysis, we found that WNV-infected females reported more symptoms than WNV-infected males, despite similar initial viremia and type I interferon responses. As the infection progressed, males exhibited a protracted cytokine response-marked by sustained CCL2 (MCP-1), CCL11 (eotaxin-1), CXCL10 (IP-10) and IL-15-that was absent in females. Our results suggest that sex differences may be a factor in sustaining WNV immunity.
Assuntos
Citocinas/biossíntese , Febre do Nilo Ocidental/metabolismo , Febre do Nilo Ocidental/virologia , Vírus do Nilo Ocidental/fisiologia , Biomarcadores , Feminino , Humanos , Mediadores da Inflamação/metabolismo , Masculino , Índice de Gravidade de Doença , Fatores Sexuais , Avaliação de Sintomas , Carga Viral , Febre do Nilo Ocidental/diagnósticoRESUMO
Double-stranded RNA (dsRNA) is a potent proinflammatory signature of viral infection and is sensed primarily by RIG-I-like receptors (RLRs). Oligomerization of RLRs following binding to cytosolic dsRNA activates and nucleates self-assembly of the mitochondrial antiviral-signaling protein (MAVS). In the current signaling model, the caspase recruitment domains of MAVS form helical fibrils that self-propagate like prions to promote signaling complex assembly. However, there is no conclusive evidence that MAVS forms fibrils in cells or with the transmembrane anchor present. We show here with super-resolution light microscopy that MAVS activation by dsRNA induces mitochondrial membrane remodeling. Quantitative image analysis at imaging resolutions as high as 32 nm shows that in the cellular context, MAVS signaling complexes and the fibrils within them are smaller than 80 nm. The transmembrane domain of MAVS is required for its membrane remodeling, interferon signaling, and proapoptotic activities. We conclude that membrane tethering of MAVS restrains its polymerization and contributes to mitochondrial remodeling and apoptosis upon dsRNA sensing.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Interferon beta/metabolismo , Membranas Mitocondriais/metabolismo , Células 3T3/virologia , Proteínas Adaptadoras de Transdução de Sinal/química , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Morte Celular/fisiologia , Citosol/fisiologia , Fibroblastos/metabolismo , Helicase IFIH1 Induzida por Interferon/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Camundongos , Camundongos Knockout , Microscopia/métodos , Membranas Mitocondriais/virologia , Proteínas do Complexo de Importação de Proteína Precursora Mitocondrial , Domínios Proteicos , RNA de Cadeia Dupla/metabolismo , Receptores de Superfície Celular/metabolismo , Transdução de Sinais , Análise de Célula Única/métodos , Febre do Nilo Ocidental/metabolismoRESUMO
Virus infections of the central nervous system (CNS) can manifest in various forms of inflammation, including that of the brain (encephalitis) and spinal cord (myelitis), all of which may have long-lasting deleterious consequences. Although the knowledge of how different viruses affect neural cells is increasing, understanding of the mechanisms by which cells respond to neurotropic viruses remains fragmented. Several virus types have the ability to infect neural tissue, and astrocytes, an abundant and heterogeneous neuroglial cell type and a key element providing CNS homeostasis, are one of the first CNS cell types to get infected. Astrocytes are morphologically closely aligned with neuronal synapses, blood vessels, and ventricle cavities, and thereby have the capacity to functionally interact with neurons and endothelial cells. In this review, we focus on the responses of astrocytes to infection by neurotropic flaviviruses, including tick-borne encephalitis virus (TBEV), Zika virus (ZIKV), West Nile virus (WNV), and Japanese encephalitis virus (JEV), which have all been confirmed to infect astrocytes and cause multiple CNS defects. Understanding these mechanisms may help design new strategies to better contain and mitigate virus- and astrocyte-dependent neuroinflammation.
Assuntos
Astrócitos/metabolismo , Astrócitos/virologia , Infecções por Flavivirus/metabolismo , Infecções por Flavivirus/virologia , Flavivirus/fisiologia , Animais , Vírus da Encefalite Japonesa (Espécie)/fisiologia , Encefalite Japonesa/virologia , Infecções por Flavivirus/patologia , Infecções por Flavivirus/transmissão , Humanos , Tropismo Viral , Febre do Nilo Ocidental/metabolismo , Febre do Nilo Ocidental/patologia , Febre do Nilo Ocidental/virologia , Vírus do Nilo Ocidental/fisiologiaRESUMO
In recent years, West Nile virus (WNV) has posed a great threat to global human health due to its explosive spread. Studying the protein-protein interactions (PPIs) between WNV and human is beneficial for understanding the pathogenesis of WNV and the immune response mechanism of human against WNV infection at the molecular level. In this study, we identified the human target proteins which interact with WNV based on protein structure similarity, and then the interacting pairs were filtered by the subcellular co-localization information. As a result, a network of 3346 interactions was constructed, involving 6 WNV proteins and 1970 human target proteins. To our knowledge, this is the first predicted interactome for WNV-human. By analyzing the topological properties and evolutionary rates of the human target proteins, it was demonstrated that these proteins tend to be the hub and bottleneck proteins in the human PPI network and are more conserved than the non-target ones. Triplet analysis showed that the target proteins are adjacent to each other in the human PPI network, suggesting that these proteins may have similar biological functions. Further, the functional enrichment analysis indicated that the target proteins are mainly involved in virus process, transcription regulation, cell adhesion, and so on. In addition, the common and specific targets were identified and compared based on the networks between WNV-human and Dengue virus II (DENV2)-human. Finally, by combining topological features and existing drug target information, we identified 30 potential anti-WNV human targets, among which 11 ones were reported to be associated with WNV infection. Communicated by Ramaswamy H. Sarma.
Assuntos
Mapeamento de Interação de Proteínas/métodos , Mapas de Interação de Proteínas , Proteínas Virais/química , Febre do Nilo Ocidental/metabolismo , Vírus do Nilo Ocidental/metabolismo , Algoritmos , Bases de Dados de Proteínas , Interações Hospedeiro-Patógeno , Humanos , Ligação Proteica , Transdução de Sinais , Proteínas Virais/metabolismo , Febre do Nilo Ocidental/virologia , Vírus do Nilo Ocidental/fisiologiaRESUMO
The MHC class II region in humans is highly polymorphic. Each MHC molecule is formed by an α and a ß chain, produced by different genes, creating an antigen-binding groove. In the groove there are several pockets into which antigens anchor and fit. The affinity of this fitting determines the recognition specificity of a given peptide. Here, based on our previous results about the association of MHC class II with the WNV disease, we examined the role of the binding pockets of HLA-DPA1, -DQA1 and-DRB1 in the severe form of the disease. In HLA-DQA1, variants in all pockets 1, 6 and 9 were found to be associated with either protection and/or susceptibility to neuroinvasion caused by WNV. Similarly, pockets 7, 9 and 10 in HLA-DRB1 were associated with severe disease. Protein modeling of these molecules revealed structural and functional differences among alleles with opposite roles concerning the development of the disease. Different amino acids in positions α52 and α66 (HLA-DQA1) significantly influenced the peptide binding while DYWLR/EFA combination (HLA-DRB1) was associated with neuronal damage. Further studies could help us understand the selectivity of pocket variants in order to create suitable peptides for an effective response.
Assuntos
Resistência à Doença/genética , Predisposição Genética para Doença , Cadeias alfa de HLA-DP/genética , Cadeias alfa de HLA-DQ/genética , Cadeias HLA-DRB1/genética , Febre do Nilo Ocidental/genética , Motivos de Aminoácidos , Sequência de Aminoácidos , Sítios de Ligação , Estudos de Coortes , Éxons , Estudos de Associação Genética , Cadeias alfa de HLA-DP/metabolismo , Cadeias alfa de HLA-DQ/metabolismo , Cadeias HLA-DRB1/metabolismo , Humanos , Ligação de Hidrogênio , Modelos Moleculares , Índice de Gravidade de Doença , Febre do Nilo Ocidental/metabolismoRESUMO
The E3 ubiquitin ligase Pellino 1 (Peli1) is a microglia-specific mediator of autoimmune encephalomyelitis. Its role in neurotropic flavivirus infection is largely unknown. Here, we report that mice deficient in Peli1 (Peli1-/-) were more resistant to lethal West Nile virus (WNV) infection and exhibited reduced viral loads in tissues and attenuated brain inflammation. Peli1 mediates chemokine and proinflammatory cytokine production in microglia and promotes T cell and macrophage infiltration into the CNS. Unexpectedly, Peli1 was required for WNV entry and replication in mouse macrophages and mouse and human neurons and microglia. It was also highly expressed on WNV-infected neurons and adjacent inflammatory cells from postmortem patients who died of acute WNV encephalitis. WNV passaged in Peli1-/- macrophages or neurons induced a lower viral load and impaired activation in WT microglia and thereby reduced lethality in mice. Smaducin-6, which blocks interactions between Peli1 and IRAK1, RIP1, and IKKε, did not inhibit WNV-triggered microglia activation. Collectively, our findings suggest a nonimmune regulatory role for Peli1 in promoting microglia activation during WNV infection and identify a potentially novel host factor for flavivirus cell entry and replication.
Assuntos
Neurônios/metabolismo , Proteínas Nucleares/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Replicação Viral/fisiologia , Febre do Nilo Ocidental/metabolismo , Vírus do Nilo Ocidental/fisiologia , Animais , Quimiocinas/genética , Quimiocinas/metabolismo , Chlorocebus aethiops , Humanos , Inflamação/genética , Inflamação/metabolismo , Inflamação/patologia , Inflamação/virologia , Macrófagos/metabolismo , Macrófagos/patologia , Macrófagos/virologia , Camundongos , Camundongos Knockout , Microglia/metabolismo , Microglia/patologia , Microglia/virologia , Neurônios/patologia , Neurônios/virologia , Proteínas Nucleares/genética , Linfócitos T/metabolismo , Linfócitos T/patologia , Ubiquitina-Proteína Ligases/genética , Células Vero , Carga Viral , Febre do Nilo Ocidental/genética , Febre do Nilo Ocidental/patologiaRESUMO
Flaviviruses are relevant animal and human pathogens that include West Nile virus (WNV), Japanese encephalitis virus, dengue virus, or Zika virus, among others. Currently, no licensed therapy is available to fight flaviviral infections. Protein kinases C (PKCs) constitute a family of multifunctional lipid-dependent isoenzymes that regulate a wide variety of cellular processes (apoptosis, differentiation, proliferation, cellular transformation, motility, adhesion, etc.) being currently considered at the front line of drug development for the treatment of diverse human disorders. PKCs have also been implicated in different steps during viral replication; however, nowadays, results regarding their role in flavivirus replication are controversial. Here we demonstrate that calphostin C and chelerythrine, two broad-PKC inhibitors that target conventional, novel and atypical PKCs, significantly inhibit WNV multiplication in cell culture without affecting cell viability. A reduction of viral yields was observed in treated cells when compared with mock-treated cells. Likewise, immunofluorescence detection of viral enveloped E protein was reduced in treated cells, as was the amount of viral RNA released to the supernatant, mainly in those treated with chelerythrine. On the other hand, two PKC inhibitors specific for conventional and novel isoforms (staurosporine and enzastaurine) did not show any significant effect in WNV multiplication. These results suggested that PKCs, more probably atypical PKCs, are likely involved in WNV multiplication, although both broad-spectrum tested drugs seem to act through different mechanisms, and point to them as potential antiviral candidates for WNV, as well as for other related flaviviruses.