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1.
Acta Virol ; 63(3): 286-291, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31507194

RESUMO

Schmallenberg virus (SBV), a neurotropic member of the genus Orthobunyavirus, infects ruminants and causes neurological lesions and fetal malformations including cerebellar hypoplasia, hydranencephaly, and porencephaly. The aim of this study is to establish intracerebral (i.c.) infection of SBV in newborn BALB/c mice and to investigate some of the transcription factors in brain. For this aim, brain samples of newborn BALB/c mice which were infected with SBV i.c. were analyzed by plaque titration and real-time RT-PCR for T-bet, Gata3, RoRγt, Foxp3 and Eomes mRNA levels. Study results showed that SBV can replicate in BALB/c mice brain and cause death of newborn mice with generation of infectious viral particles. Analyses of transcription factor mRNA levels indicated up-regulation of T-bet, Gata3, RoRγt, Foxp3 and down-regulation of Eomes. In this report, we introduce preliminary data of T cell transcription factors affected by SBV infection of BALB/c mice. Keywords: Eomes; Foxp3; Gata3; RoRγt; Schmallenberg virus; T-bet.


Assuntos
Encéfalo , Infecções por Bunyaviridae , Regulação da Expressão Gênica , Orthobunyavirus , Fatores de Transcrição , Animais , Animais Recém-Nascidos , Encéfalo/virologia , Infecções por Bunyaviridae/fisiopatologia , Camundongos , Camundongos Endogâmicos BALB C , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ruminantes , Fatores de Transcrição/genética , Replicação Viral
2.
Arch Virol ; 164(10): 2585-2592, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31377889

RESUMO

Marbled eel reovirus (MERV) is an aquareovirus (AQRV) isolated from diseased marbled eels (Anguilla marmorata) with petechial skin hemorrhage. In this study, we propagated MERV in a cell line derived from the brain of Aequidens rivulatus and purified viral particles by using a discontinuous cesium chloride gradient. Genomic RNA sequences were obtained through next-generation sequencing. MERV, similar to most other AQRVs, showed the presence of 11 double-stranded RNA segments encoding 12 proteins; however, the genome sequence displayed very little similarity to known AQRV sequences. Furthermore, the structural proteins of MERV were most closely related to American grass carp reovirus with sequence identity values of no more than 64.89%. Phylogenetic analysis based on the sequences of structural proteins indicated that MERV shows an evolutionary history between AQRV-B and -G, which belong to the saline and freshwater environment subgroups, respectively. We also observed that MERV showed a closer relationship to orthoreoviruses based on the protein sequences of NS38 and NS73. In summary, MERV is a novel AQRV that could be classified as a member of the new proposed AQRV species "Aquareovirus H". The taxonomic assignments and evolution of AQRVs thus warrant further investigation.


Assuntos
Anguilla/virologia , Doenças dos Peixes/virologia , Infecções por Reoviridae/veterinária , Reoviridae/isolamento & purificação , Animais , Encéfalo/virologia , Linhagem Celular , Genoma Viral , Sequenciamento de Nucleotídeos em Larga Escala , Microscopia Eletrônica de Transmissão , Filogenia , RNA de Cadeia Dupla/genética , RNA Viral/genética , Reoviridae/classificação , Reoviridae/genética , Infecções por Reoviridae/virologia , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Coloração e Rotulagem , Proteínas Virais/genética , Vírion/ultraestrutura , Cultura de Vírus
3.
Vet Res ; 50(1): 50, 2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31227007

RESUMO

Nervous necrosis virus (NNV), Genus Betanodavirus, is the causative agent of viral encephalopathy and retinopathy (VER), a neuropathological disease that causes fish mortalities worldwide. The NNV genome is composed of two single-stranded RNA molecules, RNA1 and RNA2, encoding the RNA polymerase and the coat protein, respectively. Betanodaviruses are classified into four genotypes: red-spotted grouper nervous necrosis virus (RGNNV), striped jack nervous necrosis virus (SJNNV), barfin flounder nervous necrosis virus (BFNNV) and tiger puffer nervous necrosis virus (TPNNV). In Southern Europe the presence of RGNNV, SJNNV and their natural reassortants (in both RNA1/RNA2 forms: RGNNV/SJNNV and SJNNV/RGNNV) has been reported. Pathology caused by these genotypes is closely linked to water temperature and the RNA1 segment encoding amino acids 1-445 has been postulated to regulate viral adaptation to temperature. Reassortants isolated from sole (RGNNV/SJNNV) show 6 substitutions in this region when compared with the RGNNV genotype (positions 41, 48, 218, 223, 238 and 289). We have demonstrated that change of these positions to those present in the RGNNV genotype cause low and delayed replication in vitro when compared with that of the wild type strain at 25 and 30 °C. The experimental infections confirmed the impact of the mutations on viral replication because at 25 °C the viral load and the mortality were significantly lower in fish infected with the mutant than in those challenged with the non-mutated virus. It was not possible to challenge fish at 30 °C because of the scarce tolerance of sole to this temperature.


Assuntos
Substituição de Aminoácidos , Linguados/virologia , Temperatura Alta , Mutação/genética , Nodaviridae/genética , Adaptação Fisiológica , Animais , Encéfalo/virologia , Linhagem Celular , Mutagênese Sítio-Dirigida , Nodaviridae/fisiologia , Replicação Viral
4.
Nat Commun ; 10(1): 2009, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-31043599

RESUMO

HIV-associated cerebrovascular events remain highly prevalent even in the current era of antiretroviral therapy (ART). We hypothesize that low-level HIV replication and associated inflammation endure despite antiretroviral treatment and affect ischemic stroke severity and outcomes. Using the EcoHIV infection model and the middle cerebral artery occlusion as the ischemic stroke model in mice, we present in vivo analysis of the relationship between HIV and stroke outcome. EcoHIV infection increases infarct size and negatively impacts tissue and functional recovery. Ischemic stroke also results in an increase in EcoHIV presence in the affected regions, suggesting post-stroke reactivation that magnifies pro-inflammatory status. Importantly, ART with a high CNS penetration effectiveness (CPE) is more beneficial than low CPE treatment in limiting tissue injury and accelerating post-stroke recovery. These results provide potential insight for treatment of HIV-infected patients that are at risk of developing cerebrovascular disease, such as ischemic stroke.


Assuntos
Antirretrovirais/farmacocinética , Barreira Hematoencefálica/metabolismo , Infarto Encefálico/tratamento farmacológico , Encéfalo/patologia , Infecções por HIV/tratamento farmacológico , Animais , Antirretrovirais/uso terapêutico , Comportamento Animal/efeitos dos fármacos , Encéfalo/irrigação sanguínea , Encéfalo/efeitos dos fármacos , Encéfalo/virologia , Infarto Encefálico/diagnóstico , Infarto Encefálico/etiologia , Modelos Animais de Doenças , Infecções por HIV/complicações , Infecções por HIV/virologia , HIV-1 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Artéria Cerebral Média/cirurgia , Permeabilidade , Recuperação de Função Fisiológica/efeitos dos fármacos , Índice de Gravidade de Doença , Resultado do Tratamento , Ativação Viral , Replicação Viral
5.
Aust Vet J ; 97(5): 133-143, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31025323

RESUMO

BACKGROUND: Between February and June 2011, more than 300 horses with unexplained neurological disease were observed in New South Wales, Australia. A virulent strain of West Nile virus (WNVNSW2011 ), of Australian origin, was shown to be the cause of many of these cases. METHODS: We reviewed the clinical descriptions provided by veterinary practitioners and the associated laboratory results. Although there was a range of clinical signs described, ataxia was the only sign that was consistently described in laboratory-confirmed cases. RESULTS: WNV was detected in brain samples by real-time reverse transcription PCR assay and virus isolation. For serological confirmation of clinical cases, an equine IgM ELISA specific for WNV was shown to be the most effective tool. CONCLUSION: A state-wide serological survey undertaken after the outbreak indicated that, contrary to expectation, although infection had been widespread, the seroprevalence of antibodies to WNV was very low, suggesting that there could be a significant risk of future disease outbreaks.


Assuntos
Encefalomielite Equina/epidemiologia , Encefalomielite Equina/virologia , Doenças dos Cavalos/epidemiologia , Doenças dos Cavalos/virologia , Febre do Nilo Ocidental/veterinária , Animais , Anticorpos Antivirais , Austrália/epidemiologia , Encéfalo/virologia , Surtos de Doenças/veterinária , Encefalomielite Equina/diagnóstico , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Doenças dos Cavalos/diagnóstico , Cavalos , Masculino , New South Wales/epidemiologia , Estudos Soroepidemiológicos , Febre do Nilo Ocidental/diagnóstico , Febre do Nilo Ocidental/epidemiologia , Vírus do Nilo Ocidental/isolamento & purificação
6.
MBio ; 10(2)2019 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-30940697

RESUMO

Hepatitis D virus (HDV) forms the genus Deltavirus unassigned to any virus family. HDV is a satellite virus and needs hepatitis B virus (HBV) to make infectious particles. Deltaviruses are thought to have evolved in humans, since for a long time, they had not been identified elsewhere. Herein we report, prompted by the recent discovery of an HDV-like agent in birds, the identification of a deltavirus in snakes (Boa constrictor) designated snake HDV (sHDV). The circular 1,711-nt RNA genome of sHDV resembles human HDV (hHDV) in its coding strategy and size. We discovered sHDV during a metatranscriptomic study of brain samples of a Boa constrictor breeding pair with central nervous system signs. Applying next-generation sequencing (NGS) to brain, blood, and liver samples from both snakes, we did not find reads matching hepadnaviruses. Sequence comparison showed the snake delta antigen (sHDAg) to be 55% and 37% identical to its human and avian counterparts. Antiserum raised against recombinant sHDAg was used in immunohistology and demonstrated a broad viral target cell spectrum, including neurons, epithelial cells, and leukocytes. Using RT-PCR, we also detected sHDV RNA in two juvenile offspring and in a water python (Liasis mackloti savuensis) in the same snake colony, potentially indicating vertical and horizontal transmission. Screening of 20 randomly selected boas from another breeder by RT-PCR revealed sHDV infection in three additional snakes. The observed broad tissue tropism and the failure to detect accompanying hepadnavirus suggest that sHDV could be a satellite virus of a currently unknown enveloped virus.IMPORTANCE So far, the only known example of deltaviruses is the hepatitis delta virus (HDV). HDV is speculated to have evolved in humans, since deltaviruses were until very recently found only in humans. Using a metatranscriptomic sequencing approach, we found a circular RNA, which resembles that of HDV in size and coding strategy, in a snake. The identification of similar deltaviruses in distantly related species other than humans indicates that the previously suggested hypotheses on the origins of deltaviruses need to be updated. It is still possible that the ancestor of deltaviruses emerged from cellular RNAs; however, it likely would have happened much earlier in evolution than previously thought. These findings open up completely new avenues in evolution and pathogenesis studies of deltaviruses.


Assuntos
Boidae/virologia , Hepatite D/veterinária , Vírus Delta da Hepatite/classificação , Vírus Delta da Hepatite/isolamento & purificação , Estruturas Animais/virologia , Animais , Encéfalo/virologia , Transmissão de Doença Infecciosa , Perfilação da Expressão Gênica , Ordem dos Genes , Hepatite D/transmissão , Hepatite D/virologia , Vírus Delta da Hepatite/genética , Sequenciamento de Nucleotídeos em Larga Escala , Imuno-Histoquímica , Filogenia , RNA/genética , RNA Viral/genética , Homologia de Sequência , Tropismo Viral
7.
J Neuroinflammation ; 16(1): 86, 2019 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-30981282

RESUMO

BACKGROUND: Impairment of the blood-brain barrier (BBB) has been associated with cognitive decline in many CNS diseases, including HIV-associated neurocognitive disorders (HAND). Recent research suggests an important role for the Sonic hedgehog (Shh) signaling pathway in the maintenance of BBB integrity under both physiological and pathological conditions. METHODS: In the present study, we sought to examine the expression of Shh and its downstream effectors in relation to brain pericytes and BBB integrity in HIV-infected humans and rhesus macaques infected with simian immunodeficiency virus (SIV), an animal model of HIV infection and CNS disease. Cortical brain tissues from uninfected (n = 4) and SIV-infected macaques with (SIVE, n = 6) or without encephalitis (SIVnoE, n = 4) were examined using multi-label, semi-quantitative immunofluorescence microscopy of Shh, netrin-1, tight junction protein zona occludens 1 (ZO1), glial fibrillary acidic protein, CD163, platelet-derived growth factor receptor b (PDGFRB), glucose transporter 1, fibrinogen, and SIV Gag p28. RESULTS: While Shh presence in the brain persisted during HIV/SIV infection, both netrin-1 immunoreactivity and the size of PDGFRB+ pericytes, a cellular source of netrin-1, were increased around non-lesion-associated vessels in encephalitis compared to uninfected brain or brain without encephalitis, but were completely absent in encephalitic lesions. Hypertrophied pericytes were strongly localized in areas of fibrinogen extravasation and showed the presence of intracellular SIVp28 and HIVp24 by immunofluorescence in all SIV and HIV encephalitis cases examined, respectively. CONCLUSIONS: The lack of pericytes and netrin-1 in encephalitic lesions, in line with downregulation of ZO1 on the fenestrated endothelium, suggests that pericyte loss, despite the strong presence of Shh, contributes to HIV/SIV-induced BBB disruption and neuropathogenesis in HAND.


Assuntos
Encéfalo/patologia , Regulação Viral da Expressão Gênica/fisiologia , Proteínas Hedgehog/metabolismo , Infecções por Lentivirus/patologia , Pericitos/metabolismo , Pericitos/patologia , Transdução de Sinais/fisiologia , Animais , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Encéfalo/virologia , Feminino , Proteína Glial Fibrilar Ácida/metabolismo , Transportador de Glucose Tipo 1/metabolismo , Infecções por HIV/patologia , Humanos , Macaca mulatta , Masculino , Netrina-1/metabolismo , Ocludina/metabolismo , Receptor beta de Fator de Crescimento Derivado de Plaquetas/metabolismo , Vírus da Imunodeficiência Símia/patogenicidade , Proteína da Zônula de Oclusão-1/metabolismo
8.
J Fish Dis ; 42(7): 959-964, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31012499

RESUMO

During a PCR-based CEV survey in Poland in 2015-2017, the virus was detected in many farms both in clinical and asymptomatic cases and in common as well as in koi carp (Cyprinus carpio). In order to evaluate the potential carrier role of fish species that share the same habitats with carp, an experimental trial was performed. Investigations carried out on specimens of bleak (Alburnus alburnus), crucian carp (Carassius carassius), European perch (Perca fluviatilis), Prussian carp (Carassius gibelio), roach (Rutilus rutilus) and tench (Tinca tinca) cohabited with CEV-infected carp yielded positive results. These species of fish were experimentally cohabited with CEV-infected common carp at a temperature of 16°C ± 1. Material from the brain, gills, spleen, kidneys, intestine and skin was investigated for the presence of CEV DNA. Similar investigations were performed with uninfected fish designated controls. Samples were tested for CEV by qPCR.


Assuntos
Carpas/virologia , Vetores de Doenças , Doenças dos Peixes/virologia , Infecções por Poxviridae/veterinária , Poxviridae/genética , Animais , Encéfalo/virologia , DNA Viral/genética , Edema/veterinária , Edema/virologia , Brânquias/virologia , Rim/virologia , Reação em Cadeia da Polimerase em Tempo Real , Baço/virologia
9.
J Fish Dis ; 42(7): 1023-1033, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31025373

RESUMO

Eleven viral haemorrhagic septicaemia virus (VHSV) genotype IVb isolates were sequenced, and their genetic variation explored to determine the source of a VHS outbreak on the eastern shore of Cayuga Lake. An active fish kill of round gobies (Neogobius melanostomus, Pallas) was intensively sampled at King Ferry, NY and nearby Long Point State Park in May 2017. Gross lesions observed on 67 moribund round gobies and two rock bass (Ambloplites rupestris, Rafinesque) included moderately haemorrhagic internal organs and erythematous areas on the head, flank, and fins. RT-qPCR tests for VHSV were positive for all 69 fish. Viral isolation on epithelioma papulosum cyprinid cells showed cytopathic effect characteristic of VHSV for six round goby samples from King Ferry. The complete nucleotide sequence of the VHSV IVb genomes of five Cayuga Lake round goby isolates were derived on an Illumina platform along with 2017 VHSV IVb isolates from round gobies collected from the following: Lake Erie near Dunkirk, NY; the St. Lawrence River near Clayton and Cape Vincent, NY; and Lake St. Lawrence near Massena, NY. The phylogenetic tree created from these aligned sequences and four other complete VHSV IVb genomes shows Cayuga Lake isolates are closely related to the Lake Erie isolates.


Assuntos
Surtos de Doenças/veterinária , Doenças dos Peixes/virologia , Peixes/virologia , Septicemia Hemorrágica Viral/epidemiologia , Novirhabdovirus/genética , Animais , Encéfalo/virologia , Feminino , Doenças dos Peixes/epidemiologia , Variação Genética , Genoma Viral , Genótipo , Lagos/virologia , Masculino , New York/epidemiologia , Novirhabdovirus/isolamento & purificação , Filogenia , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de DNA
10.
PLoS Pathog ; 15(3): e1007617, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30870531

RESUMO

Herpes simplex virus type 1 (HSV-1) is a DNA neurotropic virus, usually establishing latent infections in the trigeminal ganglia followed by periodic reactivations. Although numerous findings suggested potential links between HSV-1 and Alzheimer's disease (AD), a causal relation has not been demonstrated yet. Hence, we set up a model of recurrent HSV-1 infection in mice undergoing repeated cycles of viral reactivation. By virological and molecular analyses we found: i) HSV-1 spreading and replication in different brain regions after thermal stress-induced virus reactivations; ii) accumulation of AD hallmarks including amyloid-ß protein, tau hyperphosphorylation, and neuroinflammation markers (astrogliosis, IL-1ß and IL-6). Remarkably, the progressive accumulation of AD molecular biomarkers in neocortex and hippocampus of HSV-1 infected mice, triggered by repeated virus reactivations, correlated with increasing cognitive deficits becoming irreversible after seven cycles of reactivation. Collectively, our findings provide evidence that mild and recurrent HSV-1 infections in the central nervous system produce an AD-like phenotype and suggest that they are a risk factor for AD.


Assuntos
Transtornos Cognitivos/metabolismo , Transtornos Cognitivos/virologia , Herpesvirus Humano 1/patogenicidade , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides , Animais , Encéfalo/virologia , Cognição/fisiologia , Transtornos Cognitivos/etiologia , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/virologia , Modelos Animais de Doenças , Feminino , Herpesvirus Humano 1/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Doenças Neurodegenerativas/etiologia , Doenças Neurodegenerativas/virologia , Gânglio Trigeminal/virologia , Ativação Viral/fisiologia , Replicação Viral/fisiologia
11.
Top Magn Reson Imaging ; 28(1): 29-33, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30817678

RESUMO

In the present case series, the cause of death of infants diagnosed with congenital Zika syndrome (CZS) was lung disease (pneumonia and sepsis with massive pulmonary aspiration), probably secondary to dysphagia and reflux. The main findings in infants with a confirmed diagnosis of CZS who died were as follows: (1) calcification and hypoplasia of the lentiform nuclei, hypoplasia of the caudate nuclei, and calcification at the cortical-subcortical junction was noted in all cases (100%) and calcification of the caudate nuclei was noted in 66.7% of cases; (2) calcification in the brainstem and along the lateral wall of the lateral ventricles was noted in only the case with arthrogryposis (33.3%); and (3) lesions in the posterior fossa (hypoplasia of the brainstem and cerebellum) were noted in two cases (66.7%), including the case with arthrogryposis. The findings concerning calcifications and brain malformations obtained from non-contrast computed tomography (CT) demonstrated good agreement with findings obtained from the postmortem pathological analysis; however, CT failed to detect discontinuity of the pia mater with heterotopia, invasion of the cerebral tissue into the subarachnoid space, and discontinuity of the ependyma in the lateral ventricles with gliosis; this last feature was only imaged in the most severe case of extreme microcephaly with a simplified gyral pattern. Only histopathology showed grouped calcifications associated with scattered calcifications suggestive of the neuron morphology.


Assuntos
Encéfalo/diagnóstico por imagem , Complicações Infecciosas na Gravidez/mortalidade , Tomografia Computadorizada por Raios X/métodos , Infecção por Zika virus/congênito , Infecção por Zika virus/mortalidade , Autopsia , Encéfalo/ultraestrutura , Encéfalo/virologia , Calcinose/diagnóstico por imagem , Calcinose/etiologia , Calcinose/mortalidade , Causas de Morte , Feminino , Humanos , Lactente , Pneumopatias/etiologia , Pneumopatias/mortalidade , Microcefalia/etiologia , Microcefalia/mortalidade , Microcefalia/virologia , Gravidez , Sepse/etiologia , Sepse/mortalidade , Síndrome , Zika virus , Infecção por Zika virus/diagnóstico por imagem
12.
Tohoku J Exp Med ; 247(3): 189-195, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30890665

RESUMO

Encephalitis is an inflammatory process involving the brain parenchyma associated with neurologic dysfunction. The main causes of infectious encephalitis are viruses, including Herpes simplex virus type 1 (HSV-1). As the mortality rate of HSV-1 encephalitis could be reduced with early acyclovir treatment, it is imperative to distinguish HSV-1 encephalitis from other type of viral encephalitis as early as possible. However, sophisticated methods for definitive diagnosis of HSV-1 encephalitis are not readily available. We aimed to explore distinctive clinical and laboratory features of HSV-1 encephalitis. All of the adult patients with viral encephalitis hospitalized between 2011-2017 were enrolled, including 16 patients with HSV-1 encephalitis and 51 patients non-HSV-1 viral encephalitis. Determination of viruses in cerebrospinal fluid was performed by PCR tests. Female sex, hyponatremia, and abnormalities in MRI were independently associated with HSV-1 encephalitis (p < 0.05 for each). In particular, hyponatremia (< 135 mEq/L) was found in nine patients with HSV-1 encephalitis (56.3%) and 10 patients with non-HSV-1 viral encephalitis (19.6%) (p = 0.005). As serum sodium is determined easily and quickly in clinical practice, the presence of hyponatremia among patients with viral encephalitis could be helpful for the early diagnosis of HSV-1 encephalitis before cerebrospinal fluid PCR results were available. Moreover, the presence of positive finding in MRI could further support the diagnosis. This is the first study that compared the serum sodium levels among patients between HSV-1 and non-HSV-1 viral encephalitis. We thus propose the diagnostic value of hyponatremia for HSV-1 encephalitis.


Assuntos
Encefalite por Herpes Simples/complicações , Encefalite por Herpes Simples/virologia , Encefalite Viral/complicações , Encefalite Viral/virologia , Herpesvirus Humano 1/fisiologia , Hiponatremia/complicações , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Encéfalo/virologia , Encefalite por Herpes Simples/epidemiologia , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Prognóstico , Resultado do Tratamento
13.
Nat Microbiol ; 4(6): 1006-1013, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30833734

RESUMO

Antiviral immunity has been studied extensively from the perspective of virus-cell interactions, yet the role of virus-virus interactions remains poorly addressed. Here, we demonstrate that viral escape from interferon (IFN)-based innate immunity is a social process in which IFN-stimulating viruses determine the fitness of neighbouring viruses. We propose a general and simple social evolution framework to analyse how natural selection acts on IFN shutdown and validate it in cell cultures and mice infected with vesicular stomatitis virus. Furthermore, we find that IFN shutdown is costly because it reduces short-term viral progeny production, thus fulfilling the definition of an altruistic trait. Hence, in well-mixed populations, the IFN-blocking wild-type virus is susceptible to invasion by IFN-stimulating variants and spatial structure consequently determines whether IFN shutdown can evolve. Our findings reveal that fundamental social evolution rules govern viral innate immunity evasion and virulence and suggest possible antiviral interventions.


Assuntos
Antivirais/imunologia , Evolução Biológica , Evasão da Resposta Imune , Imunidade Inata , Animais , Encéfalo/patologia , Encéfalo/virologia , RNA Polimerases Dirigidas por DNA , Modelos Animais de Doenças , Feminino , Interações Hospedeiro-Patógeno/imunologia , Interferons/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Modelos Biológicos , Vírus da Estomatite Vesicular Indiana/efeitos dos fármacos , Vírus da Estomatite Vesicular Indiana/patogenicidade , Proteínas Virais
14.
Arch Virol ; 164(4): 1069-1083, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30783772

RESUMO

The blood-brain barrier (BBB) is a physical barrier that restricts the passage of cells and molecules as well as pathogens into the central nervous system (CNS). Some viruses enter the CNS by disrupting the BBB, while others can reach the CNS without altering the integrity of the BBB. Even though dengue virus (DENV) is not a distinctive neurotropic virus, the virus is considered to be one of the leading causes of neurological manifestations. In this study, we found that DENV is able to compromise the integrity of a murine in vitro blood-brain barrier (BBB) model, resulting in hyperpermeability, as shown by a significant increase in sucrose and albumin permeability. Infection of brain endothelial cells (ECs) was facilitated by the presence of glycans, in particular, mannose and N-acetyl glucosamine residues, on cell surfaces and viral envelope proteins, and the requirement for glycan moieties for cell infection was serotype-specific. Direct viral disruption of brain ECs was observed, leading to a significant decrease in tight-junction protein expression and peripheral localization, which contributed to the changes in BBB permeability. In conclusion, the hyperpermeability and breaching mechanism of BBB by DENV are primarily due to direct consequences of viral infection of ECs, as shown in this in vitro study.


Assuntos
Barreira Hematoencefálica/virologia , Vírus da Dengue/fisiologia , Dengue/virologia , Albuminas/metabolismo , Animais , Transporte Biológico , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Encéfalo/virologia , Técnicas de Cocultura , Dengue/metabolismo , Vírus da Dengue/classificação , Vírus da Dengue/genética , Células Endoteliais/metabolismo , Células Endoteliais/virologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Permeabilidade , Sorogrupo , Sacarose/metabolismo , Junções Íntimas/metabolismo
15.
Nat Commun ; 10(1): 706, 2019 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-30742008

RESUMO

Japanese encephalitis virus (JEV) is a leading cause of viral encephalitis. However, the mechanisms of JEV penetration of the blood-brain-barrier (BBB) remain poorly understood. Mast cells (MCs) are granulated innate immune sentinels located perivascularly, including at the BBB. Here we show that JEV activates MCs, leading to the release of granule-associated proteases in vivo. MC-deficient mice display reduced BBB permeability during JEV infection compared to congenic wild-type (WT) mice, indicating that enhanced vascular leakage in the brain during JEV infection is MC-dependent. Moreover, MCs promoted increased JEV infection in the central nervous system (CNS), enhanced neurological deficits, and reduced survival in vivo. Mechanistically, chymase, a MC-specific protease, enhances JEV-induced breakdown of the BBB and cleavage of tight-junction proteins. Chymase inhibition reversed BBB leakage, reduced brain infection and neurological deficits during JEV infection, and prolonged survival, suggesting chymase is a novel therapeutic target to prevent JEV encephalitis.


Assuntos
Quimases/metabolismo , Vírus da Encefalite Japonesa (Espécie)/patogenicidade , Encefalite Japonesa/imunologia , Encefalite Japonesa/metabolismo , Mastócitos/metabolismo , Mastócitos/virologia , Animais , Barreira Hematoencefálica/imunologia , Barreira Hematoencefálica/virologia , Encéfalo/patologia , Encéfalo/virologia , Linhagem Celular , Sistema Nervoso Central/patologia , Sistema Nervoso Central/virologia , Quimases/efeitos dos fármacos , Citocinas/metabolismo , Modelos Animais de Doenças , Encefalite Japonesa/mortalidade , Humanos , Imunidade Inata , Masculino , Mastócitos/imunologia , Mastócitos/patologia , Camundongos , Camundongos Endogâmicos C57BL , Morbidade , Permeabilidade , Análise de Sobrevida , Proteínas de Junções Íntimas
16.
PLoS Negl Trop Dis ; 13(2): e0007071, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30716104

RESUMO

The emergence of Zika virus (ZIKV) in the New World has led to more than 200,000 human infections. Perinatal infection can cause severe neurological complications, including fetal and neonatal microcephaly, and in adults there is an association with Guillain-Barré syndrome (GBS). ZIKV is transmitted to humans by Aedes sp. mosquitoes, yet little is known about its enzootic cycle in which transmission is thought to occur between arboreal Aedes sp. mosquitos and non-human primates. In the 1950s and '60s, several bat species were shown to be naturally and experimentally susceptible to ZIKV with acute viremia and seroconversion, and some developed neurological disease with viral antigen detected in the brain. Because of ZIKV emergence in the Americas, we sought to determine susceptibility of Jamaican fruit bats (Artibeus jamaicensis), one of the most common bats in the New World. Bats were inoculated with ZIKV PRVABC59 but did not show signs of disease. Bats held to 28 days post-inoculation (PI) had detectable antibody by ELISA and viral RNA was detected by qRT-PCR in the brain, saliva and urine in some of the bats. Immunoreactivity using polyclonal anti-ZIKV antibody was detected in testes, brain, lung and salivary glands plus scrotal skin. Tropism for mononuclear cells, including macrophages/microglia and fibroblasts, was seen in the aforementioned organs in addition to testicular Leydig cells. The virus likely localized to the brain via infection of Iba1+ macrophage/microglial cells. Jamaican fruit bats, therefore, may be a useful animal model for the study of ZIKV infection. This work also raises the possibility that bats may have a role in Zika virus ecology in endemic regions, and that ZIKV may pose a wildlife disease threat to bat populations.


Assuntos
Encéfalo/virologia , Quirópteros/virologia , RNA Viral/isolamento & purificação , Infecção por Zika virus/veterinária , Zika virus/fisiologia , Animais , Masculino , RNA Viral/urina , Infecção por Zika virus/virologia
17.
Viruses ; 11(2)2019 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-30744110

RESUMO

Paramyxoviruses comprise a large number of diverse viruses which in part give rise to severe diseases in affected hosts. A new genotype of feline morbillivirus, tentatively named feline morbillivirus genotype 2 (FeMV-GT2), was isolated from urine of cats with urinary tract diseases. Whole genome sequencing showed about 78% nucleotide homology to known feline morbilliviruses. The virus was isolated in permanent cell lines of feline and simian origin. To investigate the cell tropism of FeMV-GT2 feline primary epithelial cells from the kidney, the urinary bladder and the lung, peripheral blood mononuclear cells (PBMC), as well as organotypic brain slice cultures were used for infection experiments. We demonstrate that FeMV-GT2 is able to infect renal and pulmonary epithelial cells, primary cells from the cerebrum and cerebellum, as well as immune cells in the blood, especially CD4⁺ T cells, CD20⁺ B cells and monocytes. The cats used for virus isolation shed FeMV-GT2 continuously for several months despite the presence of neutralizing antibodies in the blood. Our results point towards the necessity of increased awareness for this virus when clinical signs of the aforementioned organs are encountered in cats which cannot be explained by other etiologies.


Assuntos
Encéfalo/virologia , Rim/virologia , Leucócitos Mononucleares/virologia , Pulmão/virologia , Infecções por Morbillivirus/veterinária , Morbillivirus/genética , Animais , Encéfalo/citologia , Doenças do Gato/urina , Doenças do Gato/virologia , Gatos , Células Cultivadas , Feminino , Genótipo , Rim/citologia , Pulmão/citologia , Masculino , Morbillivirus/fisiologia , Filogenia , RNA Viral , Tropismo Viral , Sequenciamento Completo do Genoma
18.
Acta Histochem ; 121(3): 368-375, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30771905

RESUMO

Lentiviral transduction is a powerful tool and widely used in neuroscience research to manipulate gene expression of cells. However, the injection of lentiviral vectors in the brain is not totally benign, it potentially induces focal neuroinflammation. Upon inflammation, microglial cells get activated and can induce major changes in tissue environment, which may interfere with experimental results. In the current study, two weeks after the injection of control viral construction in the dentate gyrus (DG) of rats, an activation of microglia was detected. To access the activation status, we used a fast and accurate method of phenotype detection - measurement of fractal dimension (FD). Microglial morphology is a key indicator of neuroinflammation, therefore FD of microglial cells may serve as a reliable index of inflammation status in the brain. Here we present a detailed description of image processing procedure of images of individual microglial cells. The method allows to preserve the complex structure of microglial cells and their thin processes on the output image, which is important for accurate FD assessment.


Assuntos
Encéfalo/citologia , Giro Denteado/citologia , Microglia/citologia , Neurônios/citologia , Animais , Encéfalo/virologia , Giro Denteado/virologia , Lentivirus/isolamento & purificação , Masculino , Microglia/virologia , Neurônios/virologia , Ratos Wistar
19.
Brain Dev ; 41(3): 263-270, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30798941

RESUMO

BACKGROUND: Norovirus is a major pathogen of gastroenteritis and is known to cause encephalitis/encephalopathy. The aim of this national survey was to clarify the clinical features of norovirus-associated encephalitis/encephalopathy (NoVE) among children in Japan. METHODS: A nationwide survey of children with NoVE was conducted using a structured research form. The initial survey asked pediatricians about children with NoVE treated between January 2011 and March 2016. The second survey obtained patient information from two sources: hospitals that responded to the initial survey and those identified as having treated cases from a literature search. RESULTS: Clinical information was available for 29 children. Their median age was 2 y 8 m. The outcome was good in 13 patients and poor in 15. The interval between the onset of gastrointestinal symptoms and that of encephalitis/encephalopathy was significantly shorter in those with a poor outcome. At the onset of an elevated serum creatinine level and an abnormal blood glucose level were correlated with a poor outcome. Regarding the subtypes of encephalitis/encephalopathy, acute encephalopathy with biphasic seizures and late reduced diffusion and hemorrhagic shock and encephalopathy syndrome were frequent. CONCLUSION: The outcome of children with NoVE was poor. Early onset of neurological symptoms, an elevated serum creatinine level, and an abnormal blood glucose level were associated with a poor outcome. No effective treatment was identified and this should be the subject of future studies.


Assuntos
Infecções por Caliciviridae/complicações , Infecções por Caliciviridae/epidemiologia , Encefalite Viral/epidemiologia , Encefalite Viral/etiologia , Adolescente , Encéfalo/diagnóstico por imagem , Encéfalo/virologia , Infecções por Caliciviridae/diagnóstico por imagem , Criança , Pré-Escolar , Encefalite Viral/diagnóstico por imagem , Feminino , Humanos , Lactente , Japão/epidemiologia , Imagem por Ressonância Magnética , Masculino , Estudos Retrospectivos , Inquéritos e Questionários
20.
Microb Pathog ; 129: 146-151, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30731189

RESUMO

To distinguish between three types of Siniperca chuatsi rhabdovirus (SCRV) viral RNA (vRNA, cRNA, and mRNA) and investigate SCRV transcription and replication dynamics in Chinese perch brain CPB cells, a novel, strand-specific, reverse transcriptase quantitative real-time PCR (RT-qPCR) assay was established. The method is based on strand-specific reverse transcription, using tagged primers to add a 'tag' sequence at the 5' end. We used the 'tag' sequence as the forward primer and a strand-specific reverse primer to quantify the three types of RNA. Three types of synthetic viral RNA were used as reference standards for validation and quantification. These assays were optimized to produce a standard curve from 102 to 107 copies/µL, with an efficiency of 91-101% and an R2 value of 0.9949-0.9999. The coefficients of variation for repeatability and reproducibility were less than 2.85% and 5.52%, respectively. Using this method, specific target RNA was detected at a 3500-70,000 fold higher level than other types of RNA. This method was also used to evaluate the dynamics of vRNA, cRNA and mRNA synthesis in CPB cells infected with SCRV. The results indicate that the intracellular dynamics of vRNA, cRNA and mRNA are different. In the earliest phase of SCRV infection, all three types of viral RNA increased very slowly. The copy number of vRNA and mRNA increased exponentially from 4 h post infection, while cRNA increased from 6 h post infection. The amount of cRNA was lower than vRNA and mRNA throughout the infection. The novel, strand-specific RT-qPCR method developed in this study provides critical data to aid the understanding of transcription and replication during SCRV infection.


Assuntos
Doenças dos Peixes/virologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Infecções por Rhabdoviridae/veterinária , Rhabdoviridae/fisiologia , Transcrição Genética , Replicação Viral , Animais , Encéfalo/virologia , Percas , RNA Viral/genética , Reprodutibilidade dos Testes , Rhabdoviridae/genética , Infecções por Rhabdoviridae/virologia , Sensibilidade e Especificidade
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