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1.
Vet Immunol Immunopathol ; 213: 109882, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31307672

RESUMO

Marek's disease virus (MDV), a highly cell-associated oncogenic avian α-herpesvirus, is the causative agent of malignant transformation of T cells in domestic chickens. The latently infected CD4+CD8- T cells carry the virus through the blood stream and establish lymphomas in the skin, visceral organs and peripheral nerves. The feather follicle epithelium (FFE) is the only anatomical site where fully infectious enveloped virions are produced and eventually disseminated into the environment to infect contact birds. Therefore, skin and FFE play a critical role as being the common source of re-infection of birds sharing the same habitat. The molecular mechanism involved in the replication and assembly of MDV in the FFE leading to the production and release of cell-free infectious virus particles is unknown and to date no viral or host gene has been implicated in the process. To examine alterations in the expression pattern of viral genes, we performed RNA-seq on the skin samples of Marek's disease virus-infected susceptible chickens at 10, 20, and 30 days post infection. For comparative analysis of the expression patterns of viral genes between the skin and spleen of the MD-susceptible and resistant lines, Real-Time RT-PCR was employed. In total, RNA-seq based analysis identified 42 viral genes that were differentially expressed in the skin of infected birds. Majority of the identified genes are involved in DNA replication, capsid, tegument, and envelop formation. Comparative analysis between the skin and spleen of MD-susceptible and resistant chicken lines, revealed significantly higher expression of the genes in the skin of either lines than the spleen. Furthermore, much higher expression of the genes was observed in the skin of the susceptible line than the resistant line.


Assuntos
Regulação Viral da Expressão Gênica , Genes Virais , Herpesvirus Galináceo 2/genética , Doença de Marek/imunologia , Pele/virologia , Animais , Galinhas/virologia , Genoma Viral , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de RNA , Pele/patologia , Organismos Livres de Patógenos Específicos , Baço/patologia , Baço/virologia
2.
BMC Bioinformatics ; 20(1): 296, 2019 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-31151381

RESUMO

BACKGROUND: Gene regulatory networks can be modelled in various ways depending on the level of detail required and biological questions addressed. One of the earliest formalisms used for modeling is a Boolean network, although these models cannot describe most temporal aspects of a biological system. Differential equation models have also been used to model gene regulatory networks, but these frameworks tend to be too detailed for large models and many quantitative parameters might not be deducible in practice. Hybrid models bridge the gap between these two model classes - these are useful when concentration changes are important while the information about precise concentrations and binding site affinities is partial. RESULTS: In this paper we study the stable behaviours of phage λ via a hybrid system based model. We identify wild type and mutant behaviours that arise for various orderings of binding site affinities. We propose experiments for detecting these behaviours: we suggest several ways of altering binding affinities with either mutations or genome rearrangements to achieve modified behaviours. The feasibility of these experiments is assessed. The interplay between the qualitative aspects of a network, e.g. network topology, and quantitative parameters, e.g. growth and degradation rates of proteins, is demonstrated. We also provide a software for exploring all feasible states of a hybrid system model and identifying all attractors. CONCLUSIONS: The behaviours of phage λ are determined mainly by the topology of this network and by the mutual order of binding affinities. Exact affinities and growth and degradation rates of proteins fine tune the system. We show that only two stable behaviours are possible for phage λ if the main constraints of λ switch are preserved - these behaviours correspond to lysis and lysogeny. We identify several variants of both lysis and lysogeny - one wild type and one modified behaviour for each. We elucidate the necessary constraints for binding site affinities to achieve both wild type lysis and lysogeny. Our software is applicable to a wide range of biological models described as a hybrid system.


Assuntos
Bacteriófago lambda/genética , Regulação Viral da Expressão Gênica , Redes Reguladoras de Genes , Bacteriófago lambda/fisiologia , Lisogenia , Modelos Biológicos , Mutação , Óperon , Software
3.
Retrovirology ; 16(1): 13, 2019 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-31036006

RESUMO

BACKGROUND: HIV-1 patients receiving combination antiretroviral therapy (cART) survive infection but require life-long adherence at high expense. In chronic cART-treated patients with undetectable viral titers, cell-associated viral RNA is still detectable, pointing to low-level viral transcriptional leakiness. To date, there are no FDA-approved drugs against HIV-1 transcription. We have previously shown that F07#13, a third generation Tat peptide mimetic with competitive activity against Cdk9/T1-Tat binding sites, inhibits HIV-1 transcription in vitro and in vivo. RESULTS: Here, we demonstrate that increasing concentrations of F07#13 (0.01, 0.1, 1 µM) cause a decrease in Tat levels in a dose-dependent manner by inhibiting the Cdk9/T1-Tat complex formation and subsequent ubiquitin-mediated Tat sequestration and degradation. Our data indicate that complexes I and IV contain distinct patterns of ubiquitinated Tat and that transcriptional inhibition induced by F07#13 causes an overall reduction in Tat levels. This reduction may be triggered by F07#13 but ultimately is mediated by TAR-gag viral RNAs that bind suppressive transcription factors (similar to 7SK, NRON, HOTAIR, and Xist lncRNAs) to enhance transcriptional gene silencing and latency. These RNAs complex with PRC2, Sin3A, and Cul4B, resulting in epigenetic modifications. Finally, we observed an F07#13-mediated decrease of viral burden by targeting the R region of the long terminal repeat (HIV-1 promoter region, LTR), promoting both paused polymerases and increased efficiency of CRISPR/Cas9 editing in infected cells. This implies that gene editing may be best performed under a repressed transcriptional state. CONCLUSIONS: Collectively, our results indicate that F07#13, which can terminate RNA Polymerase II at distinct sites, can generate scaffold RNAs, which may assemble into specific sets of "RNA Machines" that contribute to gene regulation. It remains to be seen whether these effects can also be seen in various clades that have varying promoter strength, mutant LTRs, and in patient samples.


Assuntos
Regulação Viral da Expressão Gênica/efeitos dos fármacos , HIV-1/genética , RNA não Traduzido/genética , Transcrição Genética , Antirretrovirais/farmacologia , Biomimética , Sistemas CRISPR-Cas , Linhagem Celular , Edição de Genes , Inativação Gênica , HIV-1/efeitos dos fármacos , Humanos , Regiões Promotoras Genéticas , RNA Viral/genética , Produtos do Gene tat do Vírus da Imunodeficiência Humana/química
4.
Virol J ; 16(1): 59, 2019 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-31046787

RESUMO

BACKGROUND: Much evidence has demonstrated the influence of Hepatitis B virus (HBV) mutations on the clinical course of HBV infection. As large (L) protein plays a crucial role for viral entry, we hypothesized that mutations in the pre-S1 promoter region might affect the expression of L protein and subsequently change the biological characters of virus. METHODS: Patients infected with genotype C HBV were enrolled for analysis. HBV DNA sequences were inserted into a TA cloning vector and analyzed. To evaluate the effects of mutations in the pre-S1 promoter region, promoter activity and the expression of mRNA and L protein were analyzed using HepG2 cells. RESULTS: In total, 35 patients were enrolled and 13 patients (37.1%) had a single base substitution in the pre-S1 promoter region; the most frequent substitution was a G-to-A substitution at the 2765th base (G2765A) in the Sp1 region. The HBV viral load showed a negative correlation with the substitution ratio of the Sp1 region or G2765A (r = - 0.493 and - 0.473, respectively). Among those with a viral load ≤5.0 log IU/ml, patients with the G2765A substitution showed a significantly lower HBV viral load than those with the wild-type sequence. HepG2 cells transfected with the G2765A substitution vector showed reduced luciferase activity of the pre-S1 promoter, as well as reduced expression of pre-S1 mRNA and L protein. Furthermore, the G2765A substitution greatly reduced the L protein expression level of vector-produced virus particles. CONCLUSION: G2765A substitution in the pre-S1 promoter reduced the expression of L protein and resulted in a low viral load and less severe disease in chronic HBV infections.


Assuntos
Regulação Viral da Expressão Gênica , Vírus da Hepatite B/genética , Mutação Puntual , Regiões Promotoras Genéticas , Proteínas do Envelope Viral/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Substituição de Aminoácidos , Feminino , Hepatite B Crônica/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Carga Viral , Adulto Jovem
5.
Molecules ; 24(9)2019 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-31058822

RESUMO

Foot-and-mouth disease (FMD) is a highly contagious viral disease of cloven-hoofed animals, which has significant economic consequences in affected countries. As the currently available vaccines against FMD provide no protection until 4-7 days post-vaccination, the only alternative method to control the spread of FMD virus (FMDV) during outbreaks is the application of antiviral agents. Hence, it is important to identify effective antiviral agents against FMDV infection. In this study, we found that mizoribine has potent antiviral activity against FMDV replication in IBRS-2 cells. A time-of-drug-addition assay demonstrated that mizoribine functions at the early stage of replication. Moreover, mizoribine also showed antiviral effect on FMDV in vivo. In summary, these results revealed that mizoribine could be a potential antiviral drug against FMDV.


Assuntos
Antivirais/administração & dosagem , Vírus da Febre Aftosa/fisiologia , Febre Aftosa/tratamento farmacológico , Ribonucleosídeos/administração & dosagem , Animais , Antivirais/química , Antivirais/farmacologia , Linhagem Celular , Surtos de Doenças , Febre Aftosa/epidemiologia , Febre Aftosa/virologia , Vírus da Febre Aftosa/efeitos dos fármacos , Regulação Viral da Expressão Gênica/efeitos dos fármacos , Camundongos , Ribonucleosídeos/química , Ribonucleosídeos/farmacologia , Suínos , Proteínas Virais/metabolismo , Replicação Viral/efeitos dos fármacos
6.
Biomed Res Int ; 2019: 5201790, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31080820

RESUMO

Rabbit hemorrhagic disease (RHD) is an acute, high fatal contagious disease induced by rabbit hemorrhagic disease virus (RHDV) with acute severe hepatic injury and causes huge economic loss worldwide. In order to develop an effective and reliable drug to treat this disease in clinic, a prescription formulated with baicalin, linarin, icariin, and notoginsenoside R1 (BLIN) according to the theory of syndrome differentiation and treatment in traditional Chinese veterinary medicine was applied to investigate its curative effects against RHD in vivo. The preliminary study results showed that BLIN prescription exerted good curative effect on RHD therapy. To further validate the curative effect and to investigate the possible related curative mechanisms of this drug, the survival rates, the plasma biochemical indexes of hepatic function, the plasma evaluation indexes of oxidative injury, and the RHDV gene expression levels were detected and then the correlation among these indexes was also analyzed. These results showed that BLIN prescription could significantly increase the survival rate, reduce the hepatic injury severity, alleviate the oxidative injury, and decrease the RHDV gene expression level in rabbits infected with RHDV. All these results indicate that BLIN prescription possesses outstanding curative effect against RHD, and the curative mechanism may be related to its antioxidant and anti-RHDV activities. Therefore, this prescription can be expected to be exploited into a new candidate for RHD therapy in clinic.


Assuntos
Infecções por Caliciviridae/tratamento farmacológico , Flavonoides/farmacologia , Flavonoides/uso terapêutico , Vírus da Doença Hemorrágica de Coelhos/efeitos dos fármacos , Animais , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Infecções por Caliciviridae/sangue , Infecções por Caliciviridae/patologia , Infecções por Caliciviridae/virologia , Relação Dose-Resposta a Droga , Regulação Viral da Expressão Gênica/efeitos dos fármacos , Ginsenosídeos/farmacologia , Ginsenosídeos/uso terapêutico , Glicosídeos/farmacologia , Glicosídeos/uso terapêutico , Vírus da Doença Hemorrágica de Coelhos/genética , Fígado/efeitos dos fármacos , Fígado/lesões , Fígado/patologia , Coelhos , Taxa de Sobrevida
7.
Virol Sin ; 34(2): 135-161, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31025296

RESUMO

Kaposi's sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus-8 (HHV-8), is etiologically linked to the development of Kaposi's sarcoma, primary effusion lymphoma, and multicentric Castleman's disease. These malignancies often occur in immunosuppressed individuals, making KSHV infection-associated diseases an increasing global health concern with persistence of the AIDS epidemic. KSHV exhibits biphasic life cycles between latent and lytic infection and extensive transcriptional and posttranscriptional regulation of gene expression. As a member of the herpesvirus family, KSHV has evolved many strategies to evade the host immune response, which help the virus establish a successful lifelong infection. In this review, we summarize the current research status on the biology of latent and lytic viral infection, the regulation of viral life cycles and the related pathogenesis.


Assuntos
Herpesvirus Humano 8/fisiologia , Herpesvirus Humano 8/patogenicidade , Transcrição Genética , Replicação Viral , Animais , Hiperplasia do Linfonodo Gigante/virologia , Estudos Clínicos como Assunto , Expressão Gênica , Regulação Viral da Expressão Gênica , Interações Hospedeiro-Patógeno , Humanos , Evasão da Resposta Imune , Hospedeiro Imunocomprometido , Linfoma de Efusão Primária/virologia , Camundongos , Processamento Pós-Transcricional do RNA , Sarcoma de Kaposi/virologia , Proteínas Virais/genética , Latência Viral
8.
PLoS Pathog ; 15(4): e1007632, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30943274

RESUMO

Chimeric Simian-Human Immunodeficiency Viruses (SHIVs) are an important tool for evaluating anti-HIV Env interventions in nonhuman primate (NHP) models. However, most unadapted SHIVs do not replicate well in vivo limiting their utility. Furthermore, adaptation in vivo often negatively impacts fundamental properties of the Env, including neutralization profiles. Transmitted/founder (T/F) viruses are particularly important to study since they represent viruses that initiated primary HIV-1 infections and may have unique attributes. Here we combined in vivo competition and rational design to develop novel subtype C SHIVs containing T/F envelopes. We successfully generated 19 new, infectious subtype C SHIVs, which were tested in multiple combinatorial pools in Indian-origin rhesus macaques. Infected animals attained peak viremia within 5 weeks ranging from 103 to 107 vRNA copies/mL. Sequence analysis during primary infection revealed 7 different SHIVs replicating in 8 productively infected animals with certain clones prominent in each animal. We then generated 5 variants each of 6 SHIV clones (3 that predominated and 3 undetectable after pooled in vivo inoculations), converting a serine at Env375 to methionine, tyrosine, histidine, tryptophan or phenylalanine. Overall, most Env375 mutants replicated better in vitro and in vivo than wild type with both higher and earlier peak viremia. In 4 of these SHIV clones (with and without Env375 mutations) we also created mutations at position 281 to include serine, alanine, valine, or threonine. Some Env281 mutations imparted in vitro replication dynamics similar to mutations at 375; however, clones with both mutations did not exhibit incremental benefit. Therefore, we identified unique subtype C T/F SHIVs that replicate in rhesus macaques with improved acute phase replication kinetics without altering phenotype. In vivo competition and rational design can produce functional SHIVs with globally relevant HIV-1 Envs to add to the growing number of SHIV clones for HIV-1 research in NHPs.


Assuntos
Infecções por HIV/virologia , HIV-1/genética , Mutação , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/genética , Produtos do Gene env do Vírus da Imunodeficiência Humana/metabolismo , Animais , Regulação Viral da Expressão Gênica , Humanos , Macaca mulatta , Projetos de Pesquisa , Replicação Viral , Produtos do Gene env do Vírus da Imunodeficiência Humana/genética
9.
Pol J Vet Sci ; 22(1): 163-171, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30997771

RESUMO

Duck viral hepatitis (DVH) is an acute and fatal disease of young ducklings characterized by rapid transmission and damages. The most important agent of DVH is duck hepatitis virus 1 (DHV-1). The effective control of DVH was achieved by active immunization of 1-day-old duck- lings with an attenuated DHV-1 virus vaccine. However, the attenuated virus might reverse to virulence. In this study, a DHV-1 strain, Du/CH/LBJ/090809, was identified and its genomic se- quences were determined. The genome of Du/CH/LBJ/090809 is composed of 7,692 nt excluding poly A and the virus was clustered into genotype A by comparing with other referenced DHV-1 strains. Du/CH/LBJ/090809 could lead to 30% mortality of 10-day-old specific pathogen free (SPF) ducklings. The virus was passaged serially in SPF chicken embryonated eggs and three vi- ruses, passage 16 (P16), P29 and P40, were selected for genomic analysis. P29 and P40 were used to evaluate the attenuation in duckling by inoculating the virus to 10-day-old SPF ducklings. Re- sults of vaccination-challenge assay showed that the inactivated virus P40 could evoke protection against the pathogenic parent virus. Nucleotide and amino acid sequences of the genomes of Du/ CH/LBJ/090809, P16, P29 and P40 were compared. Changes both in nucleotides and amino acids, which might be contributed to the decreasing in virulence by chicken embryo-passaging of DHV- 1, were observed. We speculated that these changes might be important in the adaption and at- tenuation of the virulent virus. Additionally, strains obtained in this study will provide potential candidate in the development of vaccines against DHV-1.


Assuntos
Patos , Vírus da Hepatite do Pato/patogenicidade , Hepatite Viral Animal/virologia , Infecções por Picornaviridae/veterinária , Doenças das Aves Domésticas/virologia , Animais , China , Regulação Viral da Expressão Gênica , Genoma Viral , Genótipo , Hepatite Viral Animal/diagnóstico , Hepatite Viral Animal/epidemiologia , Fígado/patologia , Fígado/virologia , Filogenia , Infecções por Picornaviridae/diagnóstico , Infecções por Picornaviridae/epidemiologia , Infecções por Picornaviridae/virologia , Doenças das Aves Domésticas/diagnóstico , Doenças das Aves Domésticas/epidemiologia , RNA Viral , Vacinas Atenuadas , Vacinas Virais , Virulência
10.
Virus Res ; 266: 15-24, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30951791

RESUMO

Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiological agent of Kaposi's sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman Disease (MCD). Recent mechanistic advances have discerned the importance of microRNAs in the virus-host relationship. KSHV has two modes of replication: lytic and latent phase. KSHV entry into permissive cells, establishment of infection, and maintenance of latency are contingent upon successful modulation of the host miRNA transcriptome. Apart from host cell miRNAs, KSHV also encodes viral miRNAs. Among various cellular and molecular targets, miRNAs are appearing to be key players in regulating viral pathogenesis. Therefore, the use of miRNAs as novel therapeutics has gained considerable attention as of late. This innovative approach relies on either mimicking miRNA species by identical oligonucleotides, or selective silencing of miRNA with specific oligonucleotide inhibitors. Here, we provide an overview of KSHV pathogenesis at the molecular level with special emphasis on the various roles miRNAs play during virus infection.


Assuntos
Herpesvirus Humano 8/genética , Herpesvirus Humano 8/patogenicidade , MicroRNAs/metabolismo , RNA Viral/metabolismo , Hiperplasia do Linfonodo Gigante/virologia , Regulação Viral da Expressão Gênica , Herpesvirus Humano 8/fisiologia , Humanos , Linfoma de Efusão Primária/virologia , MicroRNAs/genética , RNA Viral/genética , Sarcoma de Kaposi/virologia , Internalização do Vírus , Latência Viral , Replicação Viral
11.
Lipids Health Dis ; 18(1): 87, 2019 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-30954078

RESUMO

BACKGROUND: The homeostasis of lipid droplets (LDs) plays a crucial role in maintaining the physical metabolic processes in cells, and is regulated by many LD-associated proteins, including perilipin 5 (Plin5) in liver. As the putative sites of hepatitis C virus (HCV) virion assembly, LDs are vital to viral infection. In addition, the hepatic LD metabolism can be disturbed by non-structural HCV proteins, such as NS5A, but the details are still inexplicit. METHODS: HCV NS5A was overexpressed in the livers and hepatocytes of wild-type and Plin5-null mice. BODIPY 493/503 and oil red O staining were used to detect the lipid content in mouse livers and hepatocytes. The levels of lipids, lipid peroxidation and inflammation biomarkers were further determined. Immunofluorescence assay and co-immunoprecipitation assay were performed to investigate the relationship of Plin5 and NS5A. RESULTS: One week after adenovirus injection, livers expressing NS5A showed more inflammatory cell aggregation and more severe hepatic injuries in Plin5-null mice than in control mice, which was consistent with the increased serum levels of IL-2 and TNF-α (P < 0.05) observed in Plin5-null mice. Moreover, Plin5 deficiency in the liver and hepatocytes aggravated the elevation of MDA and 4-HNE levels induced by NS5A expression (P < 0.01). The triglyceride (TG) content was increased approximately 25% by NS5A expression in the wild-type liver and hepatocytes but was unchanged in the Plin5-null liver and hepatocytes. More importantly, Plin5 deficiency in the liver and hepatocytes exacerbated the elevation of non-esterified fatty acids (NEFAs) stimulated by NS5A expression (P < 0.05 and 0.01 respectively). Using triacsin C to block acyl-CoA biosynthesis, we found that Plin5 deficiency aggravated the NS5A-induced lipolysis of TG. In contrast, Plin5 overexpression in HepG2 cells ameliorated the NS5A-induced lipolysis and lipotoxic injuries. Immunofluorescent staining demonstrated that NS5A expression stimulated the targeting of Plin5 to the surface of the LDs in hepatocytes without altering the protein levels of Plin5. By co-IP, we found that the N-terminal domain (aa 32-128) of Plin5 was pivotal for its binding with NS5A. CONCLUSIONS: Our data highlight a protective role of Plin5 against hepatic lipotoxic injuries induced by HCV NS5A, which is helpful for understanding the steatosis and injuries in liver during HCV infection.


Assuntos
Fígado Gorduroso/genética , Hepatite C/genética , Fígado/metabolismo , Perilipina-5/genética , Proteínas não Estruturais Virais/genética , Acil Coenzima A/antagonistas & inibidores , Acil Coenzima A/biossíntese , Adenoviridae/genética , Animais , Modelos Animais de Doenças , Fígado Gorduroso/metabolismo , Fígado Gorduroso/terapia , Regulação Viral da Expressão Gênica/genética , Hepacivirus/genética , Hepacivirus/patogenicidade , Hepatite C/metabolismo , Hepatite C/patologia , Hepatite C/virologia , Hepatócitos/metabolismo , Hepatócitos/patologia , Hepatócitos/virologia , Humanos , Gotículas Lipídicas/metabolismo , Gotículas Lipídicas/patologia , Metabolismo dos Lipídeos/genética , Lipólise/genética , Fígado/lesões , Fígado/patologia , Fígado/virologia , Camundongos , Triazenos/administração & dosagem , Triglicerídeos/genética , Triglicerídeos/metabolismo , Fator de Necrose Tumoral alfa/genética
12.
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
13.
Molecules ; 24(7)2019 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-30959741

RESUMO

The present results dealing with the antiphytoviral activity of essential oil indicate that these plant metabolites can trigger a response to viral infection. The essential oil from Micromeria croatica and the main oil components ß-caryophyllene and caryophyllene oxide were tested for antiphytoviral activity on plants infected with satellite RNA associated cucumber mosaic virus. Simultaneous inoculation of virus with essential oil or with the dominant components of oil, and the treatment of plants prior to virus inoculation, resulted in a reduction of virus infection in the local and systemic host plants. Treatment with essential oil changed the level of alternative oxidase gene expression in infected Arabidopsis plants indicating a connection between the essential oil treatment, aox gene expression and the development of viral infection.


Assuntos
Satélite do Vírus do Mosaico do Pepino/antagonistas & inibidores , Cucumovirus/efeitos dos fármacos , Óleos Voláteis/farmacologia , Doenças das Plantas/prevenção & controle , Arabidopsis/efeitos dos fármacos , Arabidopsis/virologia , Cucumovirus/patogenicidade , Regulação Viral da Expressão Gênica/efeitos dos fármacos , Lamiaceae/química , Oxirredutases/antagonistas & inibidores , Doenças das Plantas/virologia
14.
Arch Virol ; 164(5): 1393-1404, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30877452

RESUMO

Many transcription factors are encoded by DNA viruses and retroviruses due to their regulatory roles in gene expression in the host cell. However, no transcriptional regulator has been identified in any reovirus. Here, a non-structural protein, NS31, encoded by grass carp reovirus genomic segment S7 was characterized. The NS31 protein is predicted to contain a helix-turn-helix (HTH)-like domain and a C-terminal acidic α-helix motif. In yeast, a fusion protein composed of the Gal4-BD domain and NS31 (BD-NS31) was able to activate the expression of reporter genes (Gal1/MEL1 promoter) without the Gal4-AD domain. We also found that NS31 activated the reporter genes in a BD-dependent manner, and both the C- and N-termini contribute to the activation function of NS31. Furthermore, NS31 homologues from other aquareoviruses were also shown to possess a similar transcriptional activation function in yeast. Thus, the aquareovirus NS31 protein appears to act as a transcriptional regulatory protein, the first one identified in a member of the family Reoviridae.


Assuntos
Carpas/virologia , Reoviridae/genética , Ativação Transcricional/genética , Proteínas não Estruturais Virais/genética , Sequência de Aminoácidos , Animais , Linhagem Celular Tumoral , Regulação Viral da Expressão Gênica/genética , Genes Reporter/genética , Células HeLa , Humanos , Proteínas Recombinantes de Fusão/genética , Saccharomyces cerevisiae/genética
15.
PLoS Pathog ; 15(3): e1007695, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30925159

RESUMO

p53, which regulates cell-cycle arrest and apoptosis, is a crucial target for viruses to release cells from cell-cycle checkpoints or to protect cells from apoptosis for their own benefit. Viral evasion mechanisms of aquatic viruses remain mysterious. Here, we report the spring viremia of carp virus (SVCV) degrading and stabilizing p53 in the ubiquitin-proteasome pathway by the N and P proteins, respectively. Early in an SVCV infection, significant induction was observed in the S phase and p53 was decreased in the protein level. Further experiments demonstrated that p53 interacted with SVCV N protein and was degraded by suppressing the K63-linked ubiquitination. However, the increase of p53 was observed late in the infection and experiments suggested that p53 was bound to SVCV P protein and stabilized by enhancing the K63-linked ubiquitination. Finally, lysine residue 358 was the key site for p53 K63-linked ubiquitination by the N and P proteins. Thus, our findings suggest that fish p53 is modulated by SVCV N and P protein in two distinct mechanisms, which uncovers the strategy for the subversion of p53-mediated host innate immune responses by aquatic viruses.


Assuntos
Rhabdoviridae/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Animais , Pontos de Checagem do Ciclo Celular/fisiologia , Vírus de DNA , Doenças dos Peixes , Regulação Viral da Expressão Gênica/genética , Células HEK293 , Humanos , Imunidade Inata , Rhabdoviridae/patogenicidade , Ubiquitinação , Viremia , Peixe-Zebra , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
16.
Vet Res Commun ; 43(2): 91-97, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30900113

RESUMO

Ovine herpesvirus-2 (OvHV-2) is the causative agent of the sheep-associated form of malignant catarrhal fever, a usually fatal lymphoproliferative disease of bison, deer and cattle. Malignant catarrhal fever is a major cause of cattle loss in Africa with approximately 7% affected annually; and in North America has significant impact on bison farming. Research into the mechanisms by which OvHV-2 induces disease in susceptible species has been hampered by a lack of a cell culture system for the virus. Ov2 is a bZIP protein encoded by OvHV-2. Proteins with bZIP domains in other herpesviruses, such as the Kaposi's sarcoma-associated herpesvirus K8 protein and the BZLF1 protein of Epstein-Barr virus are known to play important roles in lytic virus replication. Using a reporter based system, we demonstrate that Ov2 can modulate the activity of the major virus transactivator (Replication and Transcriptional Activator protein, RTA) to 1) drive expression of viral genes predicted to be required for efficient reactivation of the virus, including ORF49; and 2) differentially regulate the expression of the two virus encoded Bcl-2 homologues Ov4.5 and Ov9.


Assuntos
Gammaherpesvirinae/genética , Gammaherpesvirinae/metabolismo , Regulação Viral da Expressão Gênica/genética , Proteínas Virais/metabolismo , Transativadores/metabolismo , Proteínas Virais/genética
17.
Vet Res Commun ; 43(2): 99-104, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30888610

RESUMO

Herpesviruses encode miRNAs that target both virus and host genes; however their role in herpesvirus biology is still poorly understood. We previously identified thirty five miRNAs encoded by OvHV-2; the causative agent of malignant catarrhal fever (MCF) and are investigating the role of these miRNAs in regulating expression of OvHV-2 genes that play important roles in virus biology. Analysis, using RNAHybrid predicted that two OvHV-2 encoded miRNAs, ovhv2-miR-17-10 and ovhv2-miR-61-1, target transcripts coding for the OvHV-2 bZIP protein Ov2. In other herpesvirus bZIP proteins are known to play important roles in lytic virus replication. Here we show by Flow cytometry and western blotting that ovhv2-miR-17-10 and ovhv2-miR-61-1, reduce the expression of Ov2 protein. The predicted target sites for both miRNAs within the Ov2 gene were disrupted whilst retaining the Ov2 coding sequence. Mutation of the ovhv2-miR-61-1 target sequence restored Ov2 protein expression levels to control levels confirming the identity of its target site. However, it was not possible to determine the binding site of ovhv2-miR-17-10 possibly due to potential G:U pairing introduced during the mutation process. The targeting of Ov2 by two virus-encoded miRNAs suggests an important regulatory role for Ov2 in OvHV-2 replication or reactivation.


Assuntos
Gammaherpesvirinae/genética , Gammaherpesvirinae/metabolismo , Regulação Viral da Expressão Gênica/genética , MicroRNAs/genética , Proteínas Virais/genética , Replicação Viral/genética , MicroRNAs/metabolismo
18.
Emerg Microbes Infect ; 8(1): 291-302, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30866783

RESUMO

African swine fever virus is complex DNA virus that infects pigs with mortality rates up to 100% leading to devastating socioeconomic effected in the affected countries. There is neither a vaccine nor a treatment to control ASF. African swine fever virus genome encodes two putative SF2 RNA helicases (QP509L and Q706L). In the present study, we found that these two RNA helicases do not share a common ancestral besides sharing a sequence overlap. Although, our phylogenetic studies revealed that they are conserved among virulent and non-virulent isolates, it was possible to observe a degree of variation between isolates corresponding to different genotypes occurring in distinct geographic regions. Further experiments showed that QP509L and Q706L are actively transcribed from 4 h post infection. The immunoblot analysis revealed that both protein co-localized in the viral factories at 12 h post infection, however, QP509L was also detected in the cell nucleus. Finally, siRNA assays uncover the relevant role of these proteins during viral cycle progression, in particular, for the late transcription, genome replication, and viral progeny (a reduction of infectious particles up to 99.4% when siRNA against QP509L was used and 98.4% for siRNA against Q706L). Thus, our results suggest that both helicases are essential during viral infection, highlighting the potential use of these enzymes as target for drug and vaccine development against African swine fever.


Assuntos
Vírus da Febre Suína Africana/fisiologia , Núcleo Celular/metabolismo , RNA Helicases/genética , RNA Helicases/metabolismo , Vírus da Febre Suína Africana/enzimologia , Vírus da Febre Suína Africana/genética , Animais , Sequência Conservada , Regulação Viral da Expressão Gênica , Filogenia , Suínos , Transcrição Genética , Proteínas Virais/genética , Proteínas Virais/metabolismo , Virulência , Replicação Viral
19.
Molecules ; 24(5)2019 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-30862068

RESUMO

Enterovirus 71 (EV-A71) is the main causative pathogen of childhood hand, foot and mouth disease. Effective medicine is currently unavailable for the treatment of this viral disease. Using the fragment-hopping strategy, a series of 2-aryl-isoindolin-1-one compounds were designed, synthesized and investigated for their in vitro antiviral activity towards multiple EV-A71 clinical isolates (H, BrCr, Shenzhen98, Jiangsu52) in Vero cell culture in this study. The structure⁻activity relationship (SAR) studies identified 2-phenyl-isoindolin-1-ones as a new potent chemotype with potent antiviral activity against EV-A71. Ten out of the 24 tested compounds showed significant antiviral activity (EC50 < 10 µM) towards four EV-A71 strains. Compounds A3 and A4 exhibited broad and potent antiviral activity with the 50% effective concentration (EC50) values in the range of 1.23⁻1.76 µM. Moreover, the selectivity indices of A3 and A4 were significantly higher than those of the reference compound, pirodavir. The western blotting experiment indicated that the viral VP1 was significantly decreased at both the protein and RNA level in a dose-dependent manner following treatment with compound A3. Moreover, compound A3 inhibited the viral replication by acting on the virus entry stage. In summary, this study led to the discovery of 2-aryl-isoindolin-1-ones as a promising scaffold with potent anti-EV-A71 activities, which deserves further in-depth studies.


Assuntos
Antivirais/síntese química , Antivirais/farmacologia , Enterovirus Humano A/efeitos dos fármacos , Isoindóis/síntese química , Isoindóis/farmacologia , Animais , Antivirais/química , Linhagem Celular , Cercopithecus aethiops , Enterovirus Humano A/isolamento & purificação , Enterovirus Humano A/fisiologia , Regulação Viral da Expressão Gênica/efeitos dos fármacos , Humanos , Isoindóis/química , Testes de Sensibilidade Microbiana , Relação Estrutura-Atividade , Células Vero , Replicação Viral/efeitos dos fármacos
20.
PLoS Pathog ; 15(3): e1007667, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30901352

RESUMO

Host innate immune defences play a critical role in restricting the intracellular propagation and pathogenesis of invading viral pathogens. Here we show that the histone H3.3 chaperone HIRA (histone cell cycle regulator) associates with promyelocytic leukaemia nuclear bodies (PML-NBs) to stimulate the induction of innate immune defences against herpes simplex virus 1 (HSV-1) infection. Following the activation of innate immune signalling, HIRA localized at PML-NBs in a Janus-Associated Kinase (JAK), Cyclin Dependent Kinase (CDK), and Sp100-dependent manner. RNA-seq analysis revealed that HIRA promoted the transcriptional upregulation of a broad repertoire of host genes that regulate innate immunity to HSV-1 infection, including those involved in MHC-I antigen presentation, cytokine signalling, and interferon stimulated gene (ISG) expression. ChIP-seq analysis revealed that PML, the principle scaffolding protein of PML-NBs, was required for the enrichment of HIRA onto ISGs, identifying a role for PML in the HIRA-dependent regulation of innate immunity to virus infection. Our data identifies independent roles for HIRA in the intrinsic silencing of viral gene expression and the induction of innate immune defences to restrict the initiation and propagation of HSV-1 infection, respectively. These intracellular host defences are antagonized by the HSV-1 ubiquitin ligase ICP0, which disrupts the stable recruitment of HIRA to infecting viral genomes and PML-NBs at spatiotemporally distinct phases of infection. Our study highlights the importance of histone chaperones to regulate multiple phases of intracellular immunity to virus infection, findings that are likely to be highly pertinent in the cellular restriction of many clinically important viral pathogens.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Fibroblastos/imunologia , Infecções por Herpesviridae/imunologia , Herpesvirus Humano 1/patogenicidade , Chaperonas de Histonas/metabolismo , Interações Hospedeiro-Patógeno/imunologia , Imunidade Inata/imunologia , Fatores de Transcrição/metabolismo , Proteínas de Ciclo Celular/genética , Células Cultivadas , Fibroblastos/citologia , Fibroblastos/virologia , Regulação Viral da Expressão Gênica , Infecções por Herpesviridae/metabolismo , Infecções por Herpesviridae/virologia , Chaperonas de Histonas/genética , Humanos , Fatores de Transcrição/genética , Replicação Viral
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