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1.
Microbiol Spectr ; 11(3): e0032623, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37022262

RESUMO

Epstein-Barr virus (EBV) infects host cells and establishes a latent infection that requires evasion of host innate immunity. A variety of EBV-encoded proteins that manipulate the innate immune system have been reported, but whether other EBV proteins participate in this process is unclear. EBV-encoded envelope glycoprotein gp110 is a late protein involved in virus entry into target cells and enhancement of infectivity. Here, we reported that gp110 inhibits RIG-I-like receptor pathway-mediated promoter activity of interferon-ß (IFN-ß) as well as the transcription of downstream antiviral genes to promote viral proliferation. Mechanistically, gp110 interacts with the inhibitor of NF-κB kinase (IKKi) and restrains its K63-linked polyubiquitination, leading to attenuation of IKKi-mediated activation of NF-κB and repression of the phosphorylation and nuclear translocation of p65. Additionally, gp110 interacts with an important regulator of the Wnt signaling pathway, ß-catenin, and induces its K48-linked polyubiquitination degradation via the proteasome system, resulting in the suppression of ß-catenin-mediated IFN-ß production. Taken together, these results suggest that gp110 is a negative regulator of antiviral immunity, revealing a novel mechanism of EBV immune evasion during lytic infection. IMPORTANCE Epstein-Barr virus (EBV) is a ubiquitous pathogen that infects almost all human beings, and the persistence of EBV in the host is largely due to immune escape mediated by its encoded products. Thus, elucidation of EBV's immune escape mechanisms will provide a new direction for the design of novel antiviral strategies and vaccine development. Here, we report that EBV-encoded gp110 serves as a novel viral immune evasion factor, which inhibits RIG-I-like receptor pathway-mediated interferon-ß (IFN-ß) production. Furthermore, we found that gp110 targeted two key proteins, inhibitor of NF-κB kinase (IKKi) and ß-catenin, which mediate antiviral activity and the production of IFN-ß. gp110 inhibited K63-linked polyubiquitination of IKKi and induced ß-catenin degradation via the proteasome, resulting in decreased IFN-ß production. In summary, our data provide new insights into the EBV-mediated immune evasion surveillance strategy.


Assuntos
Infecções por Vírus Epstein-Barr , NF-kappa B , Humanos , NF-kappa B/metabolismo , Herpesvirus Humano 4/genética , Complexo de Endopeptidases do Proteassoma , beta Catenina , Interferon beta , Antivirais , Glicoproteínas
2.
J Biol Chem ; 299(5): 104613, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36931391

RESUMO

Epstein-Barr virus (EBV) is a member of the lymphotropic virus family and is highly correlated with some human malignant tumors. It has been reported that envelope glycoprotein 110 (gp110) plays an essential role in viral fusion, DNA replication, and nucleocapsid assembly of EBV. However, it has not been established whether gp110 is involved in regulating the host's innate immunity. In this study, we found that gp110 inhibits tumor necrosis factor α-mediated NF- κB promoter activity and the downstream production of NF- κB-regulated cytokines under physiological conditions. Using dual-luciferase reporter assays, we showed that gp110 might impede the NF-κB promoter activation downstream of NF-κB transactivational subunit p65. Subsequently, we used coimmunoprecipitation assays to demonstrate that gp110 interacts with p65 during EBV lytic infection, and that the C-terminal cytoplasmic region of gp110 is the key interaction domain with p65. Furthermore, we determined that gp110 can bind to the N-terminal Rel homologous and C-terminal domains of p65. Alternatively, gp110 might not disturb the association of p65 with nontransactivational subunit p50, but we showed it restrains activational phosphorylation (at Ser536) and nuclear translocation of p65, which we also found to be executed by the C-terminal cytoplasmic region of gp110. Altogether, these data suggest that the surface protein gp110 may be a vital component for EBV to antagonize the host's innate immune response, which is also helpful for revealing the infectivity and pathogenesis of EBV.


Assuntos
Infecções por Vírus Epstein-Barr , NF-kappa B , Humanos , NF-kappa B/genética , NF-kappa B/metabolismo , Herpesvirus Humano 4/metabolismo , Infecções por Vírus Epstein-Barr/genética , Fator de Transcrição RelA/genética , Fator de Transcrição RelA/metabolismo , Transdução de Sinais , Transporte Proteico
3.
Artigo em Inglês | MEDLINE | ID: mdl-31777414

RESUMO

Labeling training data is one of the most costly bottlenecks in developing machine learning-based applications. We present a first-of-its-kind study showing how existing knowledge resources from across an organization can be used as weak supervision in order to bring development time and cost down by an order of magnitude, and introduce Snorkel DryBell, a new weak supervision management system for this setting. Snorkel DryBell builds on the Snorkel framework, extending it in three critical aspects: flexible, template-based ingestion of diverse organizational knowledge, cross-feature production serving, and scalable, sampling-free execution. On three classification tasks at Google, we find that Snorkel DryBell creates classifiers of comparable quality to ones trained with tens of thousands of hand-labeled examples, converts non-servable organizational resources to servable models for an average 52% performance improvement, and executes over millions of data points in tens of minutes.

4.
ACS Appl Mater Interfaces ; 9(18): 15638-15643, 2017 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-28429589

RESUMO

Zero drift can severely deteriorate the stability of the light-dark current ratio, detectivity, and responsivity of photodetectors. In this paper, the effects of a [6,6]-phenyl-C61-butyric acid methyl ester (PCBM)-doped perovskite-based photodetector device on the inhibition of zero drift under dark state are discussed. Two kinds of photodetectors (Au/CH3NH3PbIxCl3-x/Au and Au/CH3NH3PbIxCl3-x:PCBM/Au) were prepared, and the materials and photodetector devices were measured by scanning electron microscopy, X-ray diffraction, photoluminescence, ultraviolet absorption spectra, and current-voltage and current-time measurements. It was found that similar merit parameters, including light-dark current ratio (∼102), detectivity (∼1011 Jones), and responsivity were obtained for these two kinds of photodetectors. However, the drift of Au/CH3NH3PbIxCl3-x:PCBM/Au devices is negligible, while a drift of ∼0.2 V exists in Au/CH3NH3PbIxCl3-x/Au devices. A new model is proposed based on the hindering theory of ion (vacancy) migration, and it is believed that the dopant PCBM can hinder the ion (vacancy) migration of perovskite materials to suppress the phenomenon of zero drift in perovskite-based photodetectors.

5.
Endocr Relat Cancer ; 20(3): 415-29, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23580589

RESUMO

Recent studies have suggested that FSH plays an important role in ovarian epithelial carcinogenesis. We demonstrated that FSH stimulates the proliferation and invasion of ovarian cancer cells, inhibits apoptosis and facilitates neovascularisation. Our previous work has shown that transient receptor potential channel C3 (TRPC3) contributes to the progression of human ovarian cancer. In this study, we further investigated the interaction between FSH and TRPC3. We found that FSH stimulation enhanced the expression of TRPC3 at both the mRNA and protein levels. siRNA-mediated silencing of TRPC3 expression inhibited the ability of FSH to stimulate proliferation and blocked apoptosis in ovarian cancer cell lines. FSH stimulation was associated with the up-regulation of TRPC3, while also facilitating the influx of Ca(2)(+) after treatment with a TRPC-specific agonist. Knockdown of TRPC3 abrogated FSH-stimulated Akt/PKB phosphorylation, leading to decreased expression of downstream effectors including survivin, HIF1-α and VEGF. Ovarian cancer specimens were analysed for TRPC3 expression; higher TRPC3 expression levels correlated with early relapse and worse prognosis. Association with poor disease-free survival and overall survival remained after adjusting for clinical stage and grade. In conclusion, TRPC3 plays a significant role in the stimulating activity of FSH and could be a potential therapeutic target for the treatment of ovarian cancer, particularly in postmenopausal women with elevated FSH levels.


Assuntos
Hormônio Foliculoestimulante/farmacologia , Neoplasias Ovarianas/metabolismo , Canais de Cátion TRPC/metabolismo , Adulto , Idoso , Cálcio/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias Ovarianas/patologia , Prognóstico , Proteínas Proto-Oncogênicas c-akt/metabolismo , Canais de Cátion TRPC/genética , Adulto Jovem
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