Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.728
Filtrar
3.
PLoS Pathog ; 15(9): e1008030, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31518366

RESUMO

Epstein-Barr virus (EBV) causes infectious mononucleosis and is associated with multiple human malignancies. EBV drives B-cell proliferation, which contributes to the pathogenesis of multiple lymphomas. Yet, knowledge of how EBV subverts host biosynthetic pathways to transform resting lymphocytes into activated lymphoblasts remains incomplete. Using a temporal proteomic dataset of EBV primary human B-cell infection, we identified that cholesterol and fatty acid biosynthetic pathways were amongst the most highly EBV induced. Epstein-Barr nuclear antigen 2 (EBNA2), sterol response element binding protein (SREBP) and MYC each had important roles in cholesterol and fatty acid pathway induction. Unexpectedly, HMG-CoA reductase inhibitor chemical epistasis experiments revealed that mevalonate pathway production of geranylgeranyl pyrophosphate (GGPP), rather than cholesterol, was necessary for EBV-driven B-cell outgrowth, perhaps because EBV upregulated the low-density lipoprotein receptor in newly infected cells for cholesterol uptake. Chemical and CRISPR genetic analyses highlighted downstream GGPP roles in EBV-infected cell small G protein Rab activation. Rab13 was highly EBV-induced in an EBNA3-dependent manner and served as a chaperone critical for latent membrane protein (LMP) 1 and 2A trafficking and target gene activation in newly infected and in lymphoblastoid B-cells. Collectively, these studies identify highlight multiple potential therapeutic targets for prevention of EBV-transformed B-cell growth and survival.


Assuntos
Linfócitos B/virologia , Ácidos Graxos/biossíntese , Herpesvirus Humano 4/patogenicidade , Ácido Mevalônico/metabolismo , Alquil e Aril Transferases/metabolismo , Linfócitos B/patologia , Proliferação de Células , Sobrevivência Celular , Colesterol/biossíntese , Infecções por Vírus Epstein-Barr/metabolismo , Infecções por Vírus Epstein-Barr/patologia , Infecções por Vírus Epstein-Barr/virologia , Antígenos Nucleares do Vírus Epstein-Barr/metabolismo , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/fisiologia , Interações entre Hospedeiro e Microrganismos/genética , Interações entre Hospedeiro e Microrganismos/fisiologia , Humanos , Redes e Vias Metabólicas , Proteínas Proto-Oncogênicas c-myc/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 2/genética , Proteína de Ligação a Elemento Regulador de Esterol 2/metabolismo , Proteínas Virais/metabolismo , Proteínas rab de Ligação ao GTP/metabolismo
4.
Adv Virus Res ; 104: 313-343, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31439152

RESUMO

The prototypical human γ-herpesviruses Epstein-Barr virus (EBV) and Kaposi Sarcoma-associated herpesvirus (KSHV) are involved in the development of malignancies. Like all herpesviruses, they share the establishment of latency, the typical architecture, and the conserved fusion machinery to initiate infection. The fusion machinery reflects virus-specific adaptations due to the requirements of the respective herpesvirus. For example, EBV evolved a tropism switch involving either the B- or epithelial cell-tropism complexes to activate fusion driven by gB. Most of the EBV entry proteins and their cellular receptors have been crystallized providing molecular details of the initial steps of infection. For KSHV, a variety of entry and binding receptors has also been reported but the mechanism how receptor binding activates gB-driven fusion is not as well understood as that for EBV. However, the downstream signaling pathways that promote the early steps of KSHV entry are well described. This review summarizes the current knowledge of the key players involved in EBV and KSHV entry and the cell-type specific mechanisms that allow infection of a wide variety of cell types.


Assuntos
Herpesvirus Humano 4/fisiologia , Herpesvirus Humano 8/fisiologia , Internalização do Vírus , Linfócitos B/virologia , Células Epiteliais/virologia , Humanos , Ligação Proteica , Receptores Virais/metabolismo , Proteínas Virais/metabolismo
5.
Nat Commun ; 10(1): 3256, 2019 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-31332191

RESUMO

Epstein-Barr virus (EBV) is associated with a number of diseases, including malignancies. Currently, it is not known whether patients with different EBV-associated diseases have different methylation profiles of circulating EBV DNA. Through whole-genome methylation analysis of plasma samples from patients with nasopharyngeal carcinoma (NPC), EBV-associated lymphoma and infectious mononucleosis, we demonstrate that EBV DNA methylation profiles exhibit a disease-associated pattern. This observation implies a significant potential for the development of methylation analysis of plasma EBV DNA for NPC diagnostics. We further analyse the plasma EBV DNA methylome of NPC and non-NPC subjects from a prospective screening cohort. Plasma EBV DNA fragments demonstrate differential methylation patterns between NPC and non-NPC subjects. Combining such differential methylation patterns with the fractional concentration (count) and size of plasma EBV DNA, population screening of NPC is performed with an improved positive predictive value of 35.1%, compared to a count- and size-based only protocol.


Assuntos
Metilação de DNA , DNA Viral/genética , Infecções por Vírus Epstein-Barr/complicações , Herpesvirus Humano 4/genética , Adulto , DNA Viral/sangue , Infecções por Vírus Epstein-Barr/sangue , Infecções por Vírus Epstein-Barr/virologia , Feminino , Herpesvirus Humano 4/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Carcinoma Nasofaríngeo/sangue , Carcinoma Nasofaríngeo/complicações , Carcinoma Nasofaríngeo/diagnóstico , Neoplasias Nasofaríngeas/sangue , Neoplasias Nasofaríngeas/complicações , Neoplasias Nasofaríngeas/diagnóstico , Estudos Prospectivos
6.
J Clin Pathol ; 72(10): 651-658, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31315893

RESUMO

Epstein-Barr virus (EBV) is a ubiquitous human virus which infects almost all humans during their lifetime and following the acute phase, persists for the remainder of the life of the individual. EBV infects B lymphocytes leading to their immortalisation, with persistence of the EBV genome as an episome. In the latent phase, EBV is prevented from reactivating through efficient cytotoxic cellular immunity. EBV reactivates (lytic phase) under conditions of psychological stress with consequent weakening of cellular immunity, and EBV reactivation has been shown to occur in a subset of individuals with each of a variety of cancers, autoimmune diseases, the autoimmune-like disease, chronic fatigue syndrome/myalgic encephalitis and under other circumstances such as being an inpatient in an intensive care unit. Chronic EBV reactivation is an important mechanism in the pathogenesis of many such diseases, yet is rarely tested for in immunocompetent individuals. This review summarises the pathogenesis of EBV infection, EBV reactivation and its role in disease, and methods which may be used to detect it. Known inhibitors of EBV reactivation and replication are discussed, including drugs licensed for treatment of other herpesviruses, licensed or experimental drugs for various other indications, compounds at an early stage of drug development and nutritional constituents such as vitamins and dietary supplements.


Assuntos
Antivirais/uso terapêutico , Suplementos Nutricionais , Infecções por Vírus Epstein-Barr/virologia , Genoma Viral/genética , Herpesvirus Humano 4/fisiologia , Vitaminas , Linfócitos B/virologia , Infecções por Vírus Epstein-Barr/tratamento farmacológico , Infecções por Vírus Epstein-Barr/psicologia , Herpesvirus Humano 4/efeitos dos fármacos , Herpesvirus Humano 4/patogenicidade , Interações Hospedeiro-Patógeno , Humanos , Estresse Psicológico , Ativação Viral/efeitos dos fármacos , Latência Viral , Replicação Viral/efeitos dos fármacos
7.
Cancer Immunol Immunother ; 68(8): 1317-1329, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31312900

RESUMO

BACKGROUND: Nasopharyngeal carcinoma (NPC) is an EBV-associated neoplasm occurring endemically in Southeast Asia and sporadically all over the world. In children and adolescents, high cure rates have been obtained using chemotherapy, radiochemotherapy and maintenance therapy with interferon beta (IFNß). The mechanism by which IFNß contributes to a low systemic relapse rate has not yet been fully revealed. PATIENTS AND METHODS: NK cells and serum samples from two patients with NPC were analyzed before and at different time points during IFNß therapy, for assessment of TRAIL expression and NK cell cytotoxicity. Cytotoxicity was measured using the calcein release assay and the contribution of different death effector pathways was analyzed using specific inhibitors. RESULTS: Treatment with IFNß induced TRAIL expression on patients' NK cells and increased their cytotoxicity against NPC targets in vitro. NK cell-mediated cytotoxicity was predominately mediated via TRAIL. IFNß also induced the production of soluble TRAIL (sTRAIL) by NK cells and its release upon contact with NPC cells. IFNß treatment increased serum levels of sTRAIL in patients. Moreover, sTRAIL concentrated from patients' serum samples induced apoptosis ex vivo in NPC cells from a patient-derived xenograft. CONCLUSION: Increased cytotoxicity of NK cells against NPC cells and increased serum levels of biologically active TRAIL in patients treated with IFNß could be a means to eliminate micrometastatic disease and explain the low systemic relapse rate in this patient group.


Assuntos
Infecções por Vírus Epstein-Barr/imunologia , Herpesvirus Humano 4/fisiologia , Imunoterapia/métodos , Interferon beta/uso terapêutico , Células Matadoras Naturais/imunologia , Carcinoma Nasofaríngeo/terapia , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Adolescente , Animais , Apoptose , Linhagem Celular Tumoral , Criança , Citotoxicidade Imunológica , Feminino , Humanos , Camundongos , Camundongos Nus , Carcinoma Nasofaríngeo/imunologia , Recidiva Local de Neoplasia , Resultado do Tratamento , Ensaios Antitumorais Modelo de Xenoenxerto
8.
Clin Lab ; 65(7)2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31307165

RESUMO

BACKGROUND: We report a case that presented as fever with positive Epstein-Barr Virus (EBV) IgM antibody combined with subcutaneous nodules on lower extremities and cervical lymphadenopathy firstly misdiagnosed as infectious mononucleosis, which was proven as subcutaneous panniculitis-like T-cell lymphoma by subcutaneous nodule biopsies. METHODS: Appropriate serum and bacteriological laboratory tests were carried out for the cause of fever. An ultrasound and subcutaneous nodule biopsies were performed. RESULTS: EBV IgM antibody was positive. An ultrasound revealed multiple subcutaneous nodules, which were prone to be lipoma on lower extremities and cervical lymphadenopathy. Subcutaneous nodule biopsies were firstly misdiagnosed as lipoma, while pathology consultation for the subcutaneous nodule biopsies diagnosed subcutaneous panniculitis-like T-cell lymphoma. CONCLUSIONS: When patients have persistent fever with positive EBV IgM antibody combined other system involvements, especially lymphadenopathy and multiple subcutaneous nodules, it should differentiate lymphoma from infectious diseases.


Assuntos
Febre/diagnóstico , Imunoglobulina M/imunologia , Mononucleose Infecciosa/diagnóstico , Extremidade Inferior/patologia , Linfadenopatia/diagnóstico , Linfoma de Células T/diagnóstico , Paniculite/diagnóstico , Tela Subcutânea/patologia , Adulto , Anticorpos Antivirais/imunologia , Biópsia , Diagnóstico Diferencial , Feminino , Febre/etiologia , Herpesvirus Humano 4/imunologia , Herpesvirus Humano 4/fisiologia , Humanos , Mononucleose Infecciosa/complicações , Mononucleose Infecciosa/virologia , Extremidade Inferior/virologia , Linfadenopatia/etiologia , Linfoma de Células T/complicações , Pescoço , Paniculite/complicações , Encaminhamento e Consulta , Tela Subcutânea/virologia
9.
Clin Nucl Med ; 44(10): 829-830, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31162258

RESUMO

FDG PET/CT was performed in a 20-year-old woman to find the underlying cause of hemophagocytic lymphohistiocytosis. The images revealed hypermetabolic activity in multiple lymph nodes and in the spleen. Lymphoma was suspected. However, the pathology of bone marrow, lymph nodes, and the spleen demonstrated chronic active Epstein-Barr virus-associated T-cell lymphoproliferative disorders.


Assuntos
Fluordesoxiglucose F18 , Herpesvirus Humano 4/fisiologia , Linfo-Histiocitose Hemofagocítica/complicações , Linfoma/complicações , Linfoma/virologia , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons , Linfócitos T/patologia , Proliferação de Células , Feminino , Humanos , Linfoma/diagnóstico por imagem , Adulto Jovem
10.
Oncol Rep ; 42(2): 775-784, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31173259

RESUMO

Deregulation of microRNA expression plays a significant role in several cancer types including Burkitt lymphoma (BL). MicroRNA genes may be regulated through epigenetic mechanisms, such as specific histone modifications and/or DNA methylation of CpG islands in promoter regions, or by regions that are located next to microRNA genes. Given the regulatory role of MYC in miR­29 expression, methylation as an additional mechanism for miR­29 silencing was investigated. Methylation of miR­29a/b/c in BL tumour samples and BL cell lines (BL41 and Raji) was assessed by pyrosequencing assay. BL cells were treated with 5­aza­2'­deoxicitidine (decitabine) and evaluated for miR­29a/b/c expression and methylation status. MYC, DNMT1 and DNMT3B protein expression were accessed by western blotting. For Epstein­Barr virus (EBV) microRNA (miR)­BART6 inhibition, the cells were transiently transfected with anti­BART6­5p. BL tumour samples and BL cell lines presented miR­29a/b1 and miR­29b2/c genes methylated in CpG sites located in both the promoter and enhancer regions. The treatment of BL cells with decitabine reduced methylation, induced miR­29s expression and downregulated MYC protein levels in a dose­dependent manner. Notably, inhibition of EBV miR­BART6­5p combined with decitabine enhanced miR­29 expression in an EBV­BL cell line. In conclusion, the miR­29a/b1 and miR­29b2/c genes have methylated CpG sequences at promoter and enhancer regions that may contribute to the regulation of miR­29 expression in BL tumours. The present findings indicated interplay between MYC and miR­29 regulation, highlighting the potential role of EBV­miRNAs in miR­29 regulation for BL pathogenesis.


Assuntos
Linfoma de Burkitt/patologia , Metilação de DNA , Elementos Facilitadores Genéticos , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-myc/metabolismo , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Linfoma de Burkitt/genética , Linfoma de Burkitt/metabolismo , Criança , Pré-Escolar , Ilhas de CpG , Epigênese Genética , Feminino , Herpesvirus Humano 4/fisiologia , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Masculino , Proteínas Proto-Oncogênicas c-myc/genética , Células Tumorais Cultivadas
11.
Blood ; 134(7): 591-596, 2019 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-31186275

RESUMO

Although a pathogenic role for the Epstein-Barr virus (EBV) is largely undisputed for tumors that are consistently EBV genome positive (eg, nasopharyngeal carcinoma, endemic Burkitt lymphoma), this is not the case for classical Hodgkin lymphoma (cHL), a tumor with only a variable EBV association. In light of recent developments in immunotherapeutics and small molecules targeting EBV, we believe it is now timely to reevaluate the role of EBV in cHL pathogenesis.


Assuntos
Infecções por Vírus Epstein-Barr/complicações , Herpesvirus Humano 4/fisiologia , Doença de Hodgkin/etiologia , Doença de Hodgkin/virologia , Animais , Infecções por Vírus Epstein-Barr/virologia , Regulação Viral da Expressão Gênica , Genes Virais , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/isolamento & purificação , Doença de Hodgkin/patologia , Doença de Hodgkin/terapia , Humanos , Fatores de Risco
12.
J Immunol Res ; 2019: 6720819, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31205958

RESUMO

Extracellular vesicles (EVs) are known to contain unique proteins that reflect the cells of origins. Activated T cells are reported to secrete various EVs. To establish T cell subset-specific biomarkers, we performed proteomic analysis with Th1- and Th2-derived EVs and identified HLA-DR as a Th1-dominated EV membrane protein. We designed a measurement system for CD3+CD4+, CD3+CD8+, and CD3+HLA-DR+ EVs to specifically determine EV subpopulations derived from CD4+, CD8+, and Th1-type T cells, respectively. In vitro analysis showed that CD3+CD4+ EVs and CD3+CD8+ EVs were selectively secreted from activated CD4+ and CD8+ T cells, respectively, and that CD3+HLA-DR+ EVs were actively secreted from not only Th1 but also activated CD8+ T (probably mostly Tc1) cells. To evaluate the clinical usefulness of these EVs, we measured the serum levels in patients with inflammatory diseases, including Epstein-Barr virus (EBV, n = 13) infection, atopic dermatitis (AD, n = 10), rheumatoid arthritis (RA, n = 20), and osteoarthritis (OA, n = 20) and compared the levels with those of healthy adults (n = 20). CD3 + CD4 + EVs were significantly higher in all of EBV infection, AD, RA, and OA while CD3+CD8+ EVs were higher in EBV infection, lower in RA, and not different in AD and OA relative to the control. The levels of CD3+HLA-DR+ EVs were markedly higher in EBV infection and significantly lower in AD. The results suggest that these EV subpopulations reflect in vivo activation status of total CD4+, total CD8+, and Th1/Tc1-type T cells, respectively, and may be helpful in T cell-related clinical settings, such as cancer immunotherapy and treatment of chronic infection, autoimmune diseases, and graft-versus-host disease.


Assuntos
Artrite Reumatoide/diagnóstico , Dermatite Atópica/diagnóstico , Infecções por Vírus Epstein-Barr/diagnóstico , Vesículas Extracelulares/metabolismo , Antígenos HLA-DR/metabolismo , Herpesvirus Humano 4/fisiologia , Osteoartrite/diagnóstico , Linfócitos T Citotóxicos/imunologia , Células Th1/imunologia , Biomarcadores , Células Cultivadas , Citometria de Fluxo , Humanos , Imunidade Celular , Imunofenotipagem , Ativação Linfocitária , Proteômica
13.
Genome Med ; 11(1): 26, 2019 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-31039804

RESUMO

BACKGROUND: Genome wide association studies have identified > 200 susceptibility loci accounting for much of the heritability of multiple sclerosis (MS). Epstein-Barr virus (EBV), a memory B cell tropic virus, has been identified as necessary but not sufficient for development of MS. The molecular and immunological basis for this has not been established. Infected B cell proliferation is driven by signalling through the EBV produced cell surface protein LMP1, a homologue of the MS risk gene CD40. METHODS: We have investigated transcriptomes of B cells and EBV-infected B cells at Latency III (LCLs) and identified MS risk genes with altered expression on infection and with expression levels associated with the MS risk genotype (LCLeQTLs). The association of LCLeQTL genomic burden with EBV phenotypes in vitro and in vivo was examined. The risk genotype effect on LCL proliferation with CD40 stimulation was assessed. RESULTS: These LCLeQTL MS risk SNP:gene pairs (47 identified) were over-represented in genes dysregulated between B and LCLs (p < 1.53 × 10-4), and as target loci of the EBV transcription factor EBNA2 (p < 3.17 × 10-16). Overall genetic burden of LCLeQTLs was associated with some EBV phenotypes but not others. Stimulation of the CD40 pathway by CD40L reduced LCL proliferation (p < 0.001), dependent on CD40 and TRAF3 MS risk genotypes. Both CD40 and TRAF3 risk SNPs are in binding sites for the EBV transcription factor EBNA2, with expression of each correlated with EBNA2 expression dependent on genotype. CONCLUSIONS: These data indicate targeting EBV may be of therapeutic benefit in MS.


Assuntos
Linfócitos B/metabolismo , Antígenos CD4/genética , Herpesvirus Humano 4/fisiologia , Esclerose Múltipla/genética , Polimorfismo de Nucleotídeo Único , Fator 3 Associado a Receptor de TNF/genética , Linfócitos B/virologia , Células Cultivadas , Endonucleases/genética , Herpesvirus Humano 4/patogenicidade , Humanos , Locos de Características Quantitativas , Transcriptoma , Latência Viral , Replicação Viral
14.
Biomed Pharmacother ; 116: 108984, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31129512

RESUMO

Although the Epstein-Barr virus (EBV) is a well-known human oncogenic virus, its molecular mechanisms involved in the transformation of healthy human cells remain poorly understood. In this study, human lymphocytes were isolated from the peripheral blood of healthy adults, and lymphocytes were transformed in vitro by EBV. Agilent human whole genome microarrays were used to detect the differential gene expression profiles of EBV-transformed lymphoblasts and healthy peripheral blood lymphocytes (PBLs). By constructing the gene functional network of EBV-induced lymphocyte transformation, we screened out candidate key genes in this process and verified their expression levels by real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot. In the EBV-transformed lymphoblasts, 2335 differentially expressed genes, including 1328 up-regulated and 1007 down-regulated, were screened out. Five candidate key genes, namely, PLK1, E2F1, PTPN11, BIRC5 and FYN were mainly screened out according to the results of LIMMA, String, Cytoscape software analysis. RT-qPCR and Western blot showed that PLK1, E2F1, PTPN11, BIRC5 genes had increased expression levels, and FYN gene was down-regulated in EBV-transformed lymphoblasts. Silencing of PLK1 gene in Raji cells could inhibit cell proliferation and invasion, and induce cell cycle arrest and apoptosis. In conclusion, PLK1, E2F1, PTPN11, BIRC5 and FYN are the candidate key molecules of EBV-transformed lymphocytes.


Assuntos
Transformação Celular Viral/genética , Biologia Computacional/métodos , Perfilação da Expressão Gênica , Herpesvirus Humano 4/fisiologia , Linfócitos/metabolismo , Linfócitos/virologia , Apoptose , Ciclo Celular , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular , Proliferação de Células , Regulação da Expressão Gênica , Humanos , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , RNA Interferente Pequeno/metabolismo
15.
PLoS One ; 14(5): e0217578, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31125383

RESUMO

Cellular sumoylation processes are proposed targets for anti-viral and anti-cancer therapies. We reported that Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) dysregulates cellular sumoylation processes, contributing to its oncogenic potential in EBV-associated malignancies. Ginkgolic acid and anacardic acid, known inhibitors of sumoylation, inhibit LMP1-induced protein sumoylation; however, both drugs have adverse effects in hosts. Here we test the effects of glycyrrhizic acid, a medicinal botanical extract with anti-inflammatory, anti-carcinogenic, and anti-viral properties, on cellular sumoylation processes. While glycyrrhizic acid is known to inhibit EBV penetration, its affect on cellular sumoylation processes remains to be documented. We hypothesized that glycyrrhizic acid inhibits cellular sumoylation processes and may be a viable treatment for Epstein-Barr virus-associated malignancies. Results showed that glycyrrhizic acid inhibited sumoylation processes (without affecting ubiquitination processes), limited cell growth, and induced apoptosis in multiple cell lines. Similar to ginkgolic acid; glycyrrhizic acid targeted the first step of the sumoylation process and resulted in low levels of spontaneous EBV reactivation. Glycyrrhizic acid did not affect induced reactivation of the virus, but the presence of the extract did reduce the ability of the produced virus to infect additional cells. Therefore, we propose that glycyrrhizic acid may be a potential therapeutic drug to augment the treatment of EBV-associated lymphoid malignancies.


Assuntos
Antivirais/farmacologia , Infecções por Vírus Epstein-Barr/tratamento farmacológico , Ácido Glicirrízico/farmacologia , Herpesvirus Humano 4/efeitos dos fármacos , Sumoilação/efeitos dos fármacos , Latência Viral/efeitos dos fármacos , Linhagem Celular , Infecções por Vírus Epstein-Barr/metabolismo , Células HEK293 , Herpesvirus Humano 4/fisiologia , Humanos
16.
Scand J Immunol ; 90(4): e12796, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31145476

RESUMO

Nasopharyngeal carcinoma (NPC) is one the most confusing and rare malignancy in most part of the world with significantly high occurrence in some populations of Southeast Asia, North Africa and Alaska. Apart from the dietary and environmental factors, NPC is well-associated with Epstein-Barr virus (EBV) infection in these ethnic groups. However, the internal molecular mechanism(s) for such association in specific populations is not known till date. Polymorphisms in the genes of histocompatibility locus antigens (HLA) are reported in NPC, but association of any particular polymorphism with ethnicity is not established yet. Here, we report a set of HLA polymorphisms in EBV-infected NPC samples from Northeast Indian population. These polymorphisms might play an important role for the lack of proper immune function against EBV infection and thus, eventually, for NPC generation in endemic populations like those of Northeast India.


Assuntos
Infecções por Vírus Epstein-Barr/imunologia , Grupos Étnicos , Genótipo , Antígenos HLA/genética , Herpesvirus Humano 4/fisiologia , Carcinoma Nasofaríngeo/imunologia , Neoplasias Nasofaríngeas/imunologia , Viés , Infecções por Vírus Epstein-Barr/epidemiologia , Infecções por Vírus Epstein-Barr/genética , Frequência do Gene , Predisposição Genética para Doença , Histocompatibilidade/genética , Humanos , Imunidade/genética , Índia/epidemiologia , Índia/etnologia , Carcinoma Nasofaríngeo/epidemiologia , Carcinoma Nasofaríngeo/genética , Neoplasias Nasofaríngeas/epidemiologia , Neoplasias Nasofaríngeas/genética , Polimorfismo Genético
17.
Biologicals ; 59: 29-36, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30992161

RESUMO

The utilization of the current combination of in vitro, in vivo and PCR assays for the identification of adventitious viruses in production cells has a limited range of detection. While Next Generation Sequencing (NGS) has a broader breadth of detection, it is unable to differentiate sequences from replicating viruses versus background inert sequences. In order to improve NGS specificity, we have designed a new NGS approach which targets subsets of viral RNAs only synthesized during cell infection. In order to evaluate the performance of this approach for detecting low levels of adventitious viruses, we selected two difficult virus/cell systems. This included B95-8 cells persistently infected by Human herpesvirus 4 (HHV-4) and serially diluted into HHV-4 negative Ramos cells and Madin-Darby bovine kidney cells with an early infection produced via a low dose of Bovine viral diarrhea virus. We demonstrated that the sensitivity of our RNA NGS approach was equivalent to targeted PCR with an increased specificity for the detection of viral infection. We were also able to identify a previously undetected Murine Leukemia Virus contaminant in Ramos cells. Based on these results, we conclude that this new RNA NGS approach is suitable for conducting viral safety evaluations of cells.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala/métodos , RNA Viral/genética , Análise de Sequência de RNA/métodos , Vírus/genética , Animais , Bovinos , Linhagem Celular , Linhagem Celular Tumoral , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/fisiologia , Humanos , Vírus da Leucemia Murina/genética , Vírus da Leucemia Murina/fisiologia , Camundongos , Reprodutibilidade dos Testes , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade , Viroses/diagnóstico , Viroses/virologia , Vírus/classificação
18.
PLoS Pathog ; 15(4): e1007541, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-31017975

RESUMO

DNA damage response (DDR) and selective autophagy both can be activated by reactive oxygen/nitrogen species (ROS/RNS), and both are of paramount importance in cancer development. The selective autophagy receptor and ubiquitin (Ub) sensor p62 plays a key role in their crosstalk. ROS production has been well documented in latent infection of oncogenic viruses including Epstein-Barr Virus (EBV). However, p62-mediated selective autophagy and its interplay with DDR have not been investigated in these settings. In this study, we provide evidence that considerable levels of p62-mediated selective autophagy are spontaneously induced, and correlate with ROS-Keap1-NRF2 pathway activity, in virus-transformed cells. Inhibition of autophagy results in p62 accumulation in the nucleus, and promotes ROS-induced DNA damage and cell death, as well as downregulates the DNA repair proteins CHK1 and RAD51. In contrast, MG132-mediated proteasome inhibition, which induces rigorous autophagy, promotes p62 degradation but accumulation of the DNA repair proteins CHK1 and RAD51. However, pretreatment with an autophagy inhibitor offsets the effects of MG132 on CHK1 and RAD51 levels. These findings imply that p62 accumulation in the nucleus in response to autophagy inhibition promotes proteasome-mediated CHK1 and RAD51 protein instability. This claim is further supported by the findings that transient expression of a p62 mutant, which is constitutively localized in the nucleus, in B cell lines with low endogenous p62 levels recaptures the effects of autophagy inhibition on CHK1 and RAD51 protein stability. These results indicate that proteasomal degradation of RAD51 and CHK1 is dependent on p62 accumulation in the nucleus. However, small hairpin RNA (shRNA)-mediated p62 depletion in EBV-transformed lymphoblastic cell lines (LCLs) had no apparent effects on the protein levels of CHK1 and RAD51, likely due to the constitutive localization of p62 in the cytoplasm and incomplete knockdown is insufficient to manifest its nuclear effects on these proteins. Rather, shRNA-mediated p62 depletion in EBV-transformed LCLs results in significant increases of endogenous RNF168-γH2AX damage foci and chromatin ubiquitination, indicative of activation of RNF168-mediated DNA repair mechanisms. Our results have unveiled a pivotal role for p62-mediated selective autophagy that governs DDR in the setting of oncogenic virus latent infection, and provide a novel insight into virus-mediated oncogenesis.


Assuntos
Autofagia , Transformação Celular Viral , Dano ao DNA , Infecções por Vírus Epstein-Barr/patologia , Estresse Oxidativo , Proteínas de Ligação a RNA/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Linfoma de Burkitt/genética , Linfoma de Burkitt/metabolismo , Linfoma de Burkitt/patologia , Linfoma de Burkitt/virologia , Cromatina , Reparo do DNA , Infecções por Vírus Epstein-Barr/genética , Infecções por Vírus Epstein-Barr/metabolismo , Infecções por Vírus Epstein-Barr/virologia , Herpesvirus Humano 4/fisiologia , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Complexo de Endopeptidases do Proteassoma , Proteínas de Ligação a RNA/genética , Transdução de Sinais , Ubiquitina/metabolismo , Latência Viral
19.
Virol Sin ; 34(3): 253-261, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30911896

RESUMO

Epstein-Barr virus (EBV) is an important human dsDNA virus, which has been shown to be associated with several malignancies including about 10% of gastric carcinomas. How EBV enters an epithelial cell has been an interesting project for investigation. "Cell-in-cell" infection was recently reported an efficient way for the entry of EBV into nasopharynx epithelial cells. The present approach was to explore the feasibility of this mode for EBV infection in gastric epithelial cells and the dynamic change of host inflammatory reaction. The EBV-positive lymphoblastic cells of Akata containing a GFP tag in the viral genome were co-cultured with the gastric epithelial cells (GES-1). The infection situation was observed under fluorescence and electron microscopies. Real-time quantitative PCR and Western-blotting assay were employed to detect the expression of a few specific cytokines and inflammatory factors. The results demonstrated that EBV could get into gastric epithelial cells by "cell-in-cell" infection but not fully successful due to the host fighting. IL-1ß, IL-6 and IL-8 played prominent roles in the cellular response to the infection. The activation of NF-κB and HSP70 was also required for the host antiviral response. The results imply that the gastric epithelial cells could powerfully resist the virus invader via cell-in-cell at the early stage through inflammatory and innate immune responses.


Assuntos
Formação de Célula em Célula , Células Epiteliais/virologia , Trato Gastrointestinal/virologia , Herpesvirus Humano 4/fisiologia , Linhagem Celular , Citocinas/imunologia , Células Epiteliais/imunologia , Fluorescência , Trato Gastrointestinal/citologia , Proteínas de Fluorescência Verde , Proteínas de Choque Térmico HSP72/metabolismo , Herpesvirus Humano 4/genética , Humanos , Imunidade Inata , Hibridização In Situ , Inflamação , Microscopia Eletrônica de Transmissão , NF-kappa B/metabolismo
20.
Viruses ; 11(3)2019 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-30901892

RESUMO

Epstein⁻Barr virus (EBV) is a ubiquitous virus that causes infectious mononucleosis and several types of cancer, such as Burkitt lymphoma, T/NK-cell lymphoma, and nasopharyngeal carcinoma. As a herpesvirus, it encodes more than 80 genes, many of which have not been characterized. EBV BamHI S rightward reading frame 1 (BSRF1) encodes a tegument protein that, unlike its homologs herpes simplex virus unique long 51 (UL51) and human cytomegalovirus UL71, has not been extensively investigated. To examine the role of BSRF1, we prepared knockout and revertant strains using the bacterial artificial chromosome system. Unexpectedly, the disruption of the gene had little or no effect on EBV lytic replication and the transformation of primary B cells. However, the knockdown of BSRF1 in B95-8 cells decreased progeny production. An immunofluorescence assay revealed that BSRF1 localized to the Golgi apparatus in the cytoplasm, as did its homologs. BSRF1 also associated with BamHI G leftward reading frame 3.5 (BGLF3.5), BamHI B rightward reading frame 2 (BBRF2), and BamHI A leftward reading frame 1 (BALF1), and BALF1 was incorporated into the tegument fraction with BSRF1. Taken together, our results indicate that BSRF1 plays a role in secondary envelopment or virion egress in the cytoplasm, as do its homolog genes.


Assuntos
Complexo de Golgi/virologia , Herpesvirus Humano 4/genética , Proteínas Virais/genética , Liberação de Vírus , Animais , Cromossomos Artificiais Bacterianos/genética , Citoplasma/virologia , Imunofluorescência , Técnicas de Inativação de Genes , Células HEK293 , Herpesvirus Humano 4/fisiologia , Humanos , Fases de Leitura , Células Vero , Vírion/genética , Vírion/fisiologia , Montagem de Vírus , Replicação Viral
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA