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High pressure is both an environmental challenge to which deep sea biology has to adapt, and a highly sensitive thermodynamic tool that can be used to trigger structural changes in biological molecules and assemblies. Lipid membranes are amongst the most pressure sensitive biological assemblies and pressure can have a large influence on their structure and properties. In this chapter, we will explore the use of high pressure small angle X-ray diffraction and high pressure microscopy to measure and quantify changes in the lateral structure of lipid membranes under both equilibrium high pressure conditions and in response to pressure jumps.
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Presión Hidrostática , Membrana Dobles de Lípidos , Difracción de Rayos X , Difracción de Rayos X/métodos , Membrana Dobles de Lípidos/química , Membrana Dobles de Lípidos/metabolismo , Dispersión del Ángulo Pequeño , Lípidos de la Membrana/química , Lípidos de la Membrana/metabolismo , TermodinámicaRESUMEN
Epstein-Barr virus (EBV) uses a biphasic lifecycle of latency and lytic reactivation to infect >95% of adults worldwide. Despite its central role in EBV persistence and oncogenesis, much remains unknown about how EBV latency is maintained. We used a human genome-wide CRISPR/Cas9 screen to identify that the nuclear protein SFPQ was critical for latency. SFPQ supported expression of linker histone H1, which stabilizes nucleosomes and regulates nuclear architecture, but has not been previously implicated in EBV gene regulation. H1 occupied latent EBV genomes, including the immediate early gene BZLF1 promoter. Upon reactivation, SFPQ was sequestered into sub-nuclear puncta, and EBV genomic H1 occupancy diminished. Enforced H1 expression blocked EBV reactivation upon SFPQ knockout, confirming it as necessary downstream of SFPQ. SFPQ knockout triggered reactivation of EBV in B and epithelial cells, as well as of Kaposi's sarcoma-associated herpesvirus in B cells, suggesting a conserved gamma-herpesvirus role. These findings highlight SFPQ as a major regulator of H1 expression and EBV latency.
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Herpesvirus Humano 4 , Histonas , Factor de Empalme Asociado a PTB , Activación Viral , Latencia del Virus , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/fisiología , Humanos , Histonas/metabolismo , Activación Viral/genética , Latencia del Virus/genética , Factor de Empalme Asociado a PTB/metabolismo , Factor de Empalme Asociado a PTB/genética , Regulación Viral de la Expresión Génica , Linfocitos B/virología , Linfocitos B/metabolismo , Infecciones por Virus de Epstein-Barr/virología , Infecciones por Virus de Epstein-Barr/genética , Infecciones por Virus de Epstein-Barr/metabolismo , Sistemas CRISPR-Cas , Regiones Promotoras Genéticas/genética , Transactivadores/metabolismo , Transactivadores/genética , Genoma ViralRESUMEN
Epstein-Barr virus (EBV) persistently infects 95% of adults worldwide and is associated with multiple human lymphomas that express characteristic EBV latency programs used by the virus to navigate the B-cell compartment. Upon primary infection, the EBV latency III program, comprised of six Epstein-Barr Nuclear Antigens (EBNA) and two Latent Membrane Protein (LMP) antigens, drives infected B-cells into germinal center (GC). By incompletely understood mechanisms, GC microenvironmental cues trigger the EBV genome to switch to the latency II program, comprised of EBNA1, LMP1 and LMP2A and observed in GC-derived Hodgkin lymphoma. To gain insights into pathways and epigenetic mechanisms that control EBV latency reprogramming as EBV-infected B-cells encounter microenvironmental cues, we characterized GC cytokine effects on EBV latency protein expression and on the EBV epigenome. We confirmed and extended prior studies highlighting GC cytokine effects in support of the latency II transition. The T-follicular helper cytokine interleukin 21 (IL-21), which is a major regulator of GC responses, and to a lesser extent IL-4 and IL-10, hyper-induced LMP1 expression, while repressing EBNA expression. However, follicular dendritic cell cytokines including IL-15 and IL-27 downmodulate EBNA but not LMP1 expression. CRISPR editing highlighted that STAT3 and STAT5 were necessary for cytokine mediated EBNA silencing via epigenetic effects at the EBV genomic C promoter. By contrast, STAT3 was instead necessary for LMP1 promoter epigenetic remodeling, including gain of activating histone chromatin marks and loss of repressive polycomb repressive complex silencing marks. Thus, EBV has evolved to coopt STAT signaling to oppositely regulate the epigenetic status of key viral genomic promoters in response to GC cytokine cues.
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Epigénesis Genética , Infecciones por Virus de Epstein-Barr , Regulación Viral de la Expresión Génica , Centro Germinal , Herpesvirus Humano 4 , Latencia del Virus , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/fisiología , Humanos , Centro Germinal/inmunología , Centro Germinal/virología , Infecciones por Virus de Epstein-Barr/virología , Infecciones por Virus de Epstein-Barr/genética , Infecciones por Virus de Epstein-Barr/inmunología , Citocinas/metabolismo , Linfocitos B/virología , Linfocitos B/metabolismoRESUMEN
Cancers associated with the oncogenic gammaherpesviruses, Epstein-Barr virus and Kaposi sarcoma herpesvirus, are notable for their constitutive activation of the transcription factor signal transducer and activator of transcription 3 (STAT3). To better understand the role of STAT3 during gammaherpesvirus latency and the B cell response to infection, we used the model pathogen murine gammaherpesvirus 68 (MHV68). Genetic deletion of STAT3 in B cells of CD19cre/+Stat3f/f mice reduced peak MHV68 latency approximately sevenfold. However, infected CD19cre/+Stat3f/f mice exhibited disordered germinal centers and heightened virus-specific CD8 T cell responses compared to wild-type (WT) littermates. To circumvent the systemic immune alterations observed in the B cell-STAT3 knockout mice and more directly evaluate intrinsic roles for STAT3, we generated mixed bone marrow chimeric mice consisting of WT and STAT3 knockout B cells. We discovered a dramatic reduction in latency in STAT3 knockout B cells compared to their WT B cell counterparts in the same lymphoid organ. RNA sequencing of sorted germinal center B cells revealed that MHV68 infection shifts the gene signature toward proliferation and away from type I and type II IFN responses. Loss of STAT3 largely reversed the virus-driven transcriptional shift without impacting the viral gene expression program. STAT3 promoted B cell processes of the germinal center, including IL-21-stimulated downregulation of surface CD23 on B cells infected with MHV68 or EBV. Together, our data provide mechanistic insights into the role of STAT3 as a latency determinant in B cells for oncogenic gammaherpesviruses.IMPORTANCEThere are no directed therapies to the latency program of the human gammaherpesviruses, Epstein-Barr virus and Kaposi sarcoma herpesvirus. Activated host factor signal transducer and activator of transcription 3 (STAT3) is a hallmark of cancers caused by these viruses. We applied the murine gammaherpesvirus pathogen system to explore STAT3 function upon primary B cell infection in the host. Since STAT3 deletion in all CD19+ B cells of infected mice led to altered B and T cell responses, we generated chimeric mice with both normal and STAT3-deleted B cells. B cells lacking STAT3 failed to support virus latency compared to normal B cells from the same infected animal. Loss of STAT3 impaired B cell proliferation and differentiation and led to a striking upregulation of interferon-stimulated genes. These findings expand our understanding of STAT3-dependent processes that are key to its function as a pro-viral latency determinant for oncogenic gammaherpesviruses in B cells and may provide novel therapeutic targets.
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Infecciones por Virus de Epstein-Barr , Gammaherpesvirinae , Infecciones por Herpesviridae , Herpesvirus Humano 8 , Rhadinovirus , Sarcoma de Kaposi , Animales , Humanos , Ratones , Gammaherpesvirinae/genética , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/metabolismo , Herpesvirus Humano 8/metabolismo , Ratones Endogámicos C57BL , Rhadinovirus/genética , Factor de Transcripción STAT3/genética , Factor de Transcripción STAT3/metabolismo , Latencia del Virus/genéticaRESUMEN
IMPORTANCE: Marek's disease virus (MDV) is a highly infectious and oncogenic virus that can induce severe T cell lymphomas in chickens. MDV encodes more than 100 genes, most of which have unknown functions. This work indicated that the LORF9 gene is necessary for MDV early cytolytic replication in B lymphocytes. In addition, we have found that the LORF9 deletion mutant has a comparative immunological protective effect with CVI988/Rispens vaccine strain against very virulent MDV challenge. This is a significant discovery that LORF9 can be exploited as a possible target for the development of an MDV gene deletion vaccine.
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Herpesvirus Gallináceo 2 , Vacunas contra la Enfermedad de Marek , Enfermedad de Marek , Enfermedades de las Aves de Corral , Animales , Linfocitos B , Pollos , Eliminación de Gen , Herpesvirus Gallináceo 2/genética , Enfermedad de Marek/prevención & control , Enfermedad de Marek/genética , Vacunas contra la Enfermedad de Marek/genética , Replicación ViralRESUMEN
Radiotherapy could regulate systemic antitumor immunity, while the immune state in the tumor microenvironment (TME) also affects the efficacy of radiotherapy. We have found that higher CD8+ T cell infiltration is associated with longer overall survival of lung adenocarcinoma and melanoma patients receiving radiotherapy. 8-Gray radiation increased the transcriptional levels of chemokines in tumor cells in vitro. However, it was not sufficient to induce significant lymphocyte infiltration in vivo. Dipeptidyl peptidase 4 (DPP4) has been reported to inactivate chemokines via post-translational truncation. Single-cell sequencing revealed that dendritic cells (DCs) had a higher DPP4 expression among other cells in the TME and upregulated DPP4 expression after radiation. Combining a DPP4 inhibitor with radiotherapy could promote chemokines expression and T cell infiltration in the TME, enhancing the antitumor effect of radiotherapy. Moreover, this therapy further enhanced the therapeutic efficacy of anti-PD-1. In this study, we demonstrated the underlying mechanism of why radiotherapy failed to induce sufficient T cell infiltration and proposed an effective strategy to promote T cell infiltration and sensitize radiotherapy. These findings demonstrate the translational value of DPP4 inhibition as a complementary approach to enhance the efficacy of radiotherapy and the combination of radiotherapy with immunotherapy.
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Inhibidores de la Dipeptidil-Peptidasa IV , Neoplasias , Humanos , Dipeptidil Peptidasa 4/genética , Inhibidores de la Dipeptidil-Peptidasa IV/farmacología , Inhibidores de la Dipeptidil-Peptidasa IV/uso terapéutico , Quimiocinas/metabolismo , Neoplasias/tratamiento farmacológico , Linfocitos T CD8-positivos , Microambiente TumoralRESUMEN
BACKGROUND: Lamellibrachia luymesi dominates cold sulfide-hydrocarbon seeps and is known for its ability to consume bacteria for energy. The symbiotic relationship between tubeworms and bacteria with particular adaptations to chemosynthetic environments has received attention. However, metabolic studies have primarily focused on the mechanisms and pathways of the bacterial symbionts, while studies on the animal hosts are limited. RESULTS: Here, we sequenced the transcriptome of L. luymesi and generated a transcriptomic database containing 79,464 transcript sequences. Based on GO and KEGG annotations, we identified transcripts related to sulfur metabolism, sterol biosynthesis, trehalose synthesis, and hydrolysis. Our in-depth analysis identified sulfation pathways in L. luymesi, and sulfate activation might be an important detoxification pathway for promoting sulfur cycling, reducing byproducts of sulfide metabolism, and converting sulfur compounds to sulfur-containing organics, which are essential for symbiotic survival. Moreover, sulfide can serve directly as a sulfur source for cysteine synthesis in L. luymesi. The existence of two pathways for cysteine synthesis might ensure its participation in the formation of proteins, heavy metal detoxification, and the sulfide-binding function of haemoglobin. Furthermore, our data suggested that cold-seep tubeworm is capable of de novo sterol biosynthesis, as well as incorporation and transformation of cycloartenol and lanosterol into unconventional sterols, and the critical enzyme involved in this process might have properties similar to those in the enzymes from plants or fungi. Finally, trehalose synthesis in L. luymesi occurs via the trehalose-6-phosphate synthase (TPS) and trehalose-6-phosphate phosphatase (TPP) pathways. The TPP gene has not been identified, whereas the TPS gene encodes a protein harbouring conserved TPS/OtsA and TPP/OtsB domains. The presence of multiple trehalases that catalyse trehalose hydrolysis could indicate the different roles of trehalase in cold-seep tubeworms. CONCLUSIONS: We elucidated several molecular pathways of sulfate activation, cysteine and cholesterol synthesis, and trehalose metabolism. Contrary to the previous analysis, two pathways for cysteine synthesis and the cycloartenol-C-24-methyltransferase gene were identified in animals for the first time. The present study provides new insights into particular adaptations to chemosynthetic environments in L. luymesi and can serve as the basis for future molecular studies on host-symbiont interactions and biological evolution.
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Poliquetos , Trehalosa , Animales , Esteroles , Cisteína , Hidrocarburos , Azufre , Sulfuros/metabolismo , Sulfatos/metabolismoRESUMEN
Ethylene induces anthocyanin biosynthesis in most fruits, including apple (Malus domestica) and plum (Prunus spp.). By contrast, ethylene inhibits anthocyanin biosynthesis in pear (Pyrus spp.), but the underlying molecular mechanism remains unclear. In this study, we identified and characterized an ethylene-induced ETHYLENE RESPONSE FACTOR (ERF) transcription factor, PpETHYLENE RESPONSE FACTOR9 (PpERF9), which functions as a transcriptional repressor. Our analyses indicated PpERF9 can directly inhibit expression of the MYB transcription factor gene PpMYB114 by binding to its promoter. Additionally, PpERF9 inhibits the expression of the transcription factor gene PpRELATED TO APETALA2.4 (PpRAP2.4), which activates PpMYB114 expression, by binding to its promoter, thus forming a PpERF9-PpRAP2.4-PpMYB114 regulatory circuit. Furthermore, PpERF9 interacts with the co-repressor PpTOPLESS1 (PpTPL1) via EAR motifs to form a complex that removes the acetyl group on histone H3 and maintains low levels of acetylated H3 in the PpMYB114 and PpRAP2.4 promoter regions. The resulting suppressed expression of these 2 genes leads to decreased anthocyanin biosynthesis in pear. Collectively, these results indicate that ethylene inhibits anthocyanin biosynthesis by a mechanism that involves PpERF9-PpTPL1 complex-mediated histone deacetylation of PpMYB114 and PpRAP2.4. The data presented herein will be useful for clarifying the relationship between chromatin status and hormone signaling, with implications for plant biology research.
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Malus , Pyrus , Pyrus/genética , Pyrus/metabolismo , Factores de Transcripción/metabolismo , Antocianinas/metabolismo , Histonas/metabolismo , Regulación de la Expresión Génica de las Plantas , Etilenos/metabolismo , Frutas/metabolismo , Malus/genética , Malus/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismoRESUMEN
Dynamic alteration of the epitranscriptome exerts regulatory effects on the lifecycle of oncogenic viruses in vitro. However, little is known about these effects in vivo because of the general lack of suitable animal infection models of these viruses. Using a model of rapid-onset Marek's disease lymphoma in chickens, we investigated changes in viral and host messenger RNA (mRNA) N6-methyladenosine (m6 A) modification during Marek's disease virus (MDV) infection in vivo. We found that the expression of major epitranscriptomic proteins varies among viral infection phases, reprogramming both the viral and the host epitranscriptomes. Specifically, the methyltransferase-like 3 (METTL3)/14 complex was suppressed during the lytic and reactivation phases of the MDV lifecycle, whereas its expression was increased during the latent phase and in MDV-induced tumors. METTL3/14 overexpression inhibits, whereas METTL3/14 knockdown enhances, MDV gene expression and replication. These findings reveal the dynamic features of the mRNA m6 A modification program during viral replication in vivo, especially in relation to key pathways involved in tumorigenesis.
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Enfermedad de Marek , Animales , Enfermedad de Marek/genética , Virus Oncogénicos/genética , Pollos , ARN Mensajero/genética , ARN Mensajero/metabolismoRESUMEN
Previous studies focused on the effects of light on fruit appearance, especially the peel color. However, the effect of light on fruit internal quality and the underlying mechanisms are unclear. In this study, we analyzed the effects of blue light on the appearance and internal quality of mango fruit (Mangifera indica L.). Blue light simultaneously induced peel anthocyanin and flesh sucrose/carotenoid biosynthesis in mango fruit. Analyses of co-expression networks and gene expression trends in mango fruit peel and flesh identified candidate genes, including transcription factor genes, involved in blue light-regulated anthocyanin, carotenoid, and sucrose biosynthesis pathways. Key blue light signaling-related genes (MiCRY and MiHY5) and blue light-triggered phytohormones were involved in these pathways. Additionally, there were common and tissue-specific pathways for the blue light-promoted accumulation of anthocyanins, carotenoids, and sucrose. Our results provide new insights into the regulatory effects of light on the appearance and internal quality of mango fruit.
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Antocianinas , Mangifera , Antocianinas/metabolismo , Mangifera/genética , Frutas/genética , Frutas/metabolismo , Transcriptoma , Carotenoides/metabolismo , Regulación de la Expresión Génica de las PlantasRESUMEN
Marek's disease virus (MDV) induces immunosuppression and neoplastic disease in chickens. The virus is controllable via an attenuated meq deletion mutant virus, which has the disadvantage of retaining the ability to induce lymphoid organ atrophy. To overcome this deficiency and produce more vaccine candidates, a recombinant MDV was generated from the highly virulent Md5BAC strain, in which both meq and a cytolytic replication-related gene, pp38, were deleted. Replication of the double deletion virus, Md5BAC ΔmeqΔpp38, was comparable with that of the parental virus in vitro. The double deletion virus was shown to be fully attenuated and to reduce lymphoid organ atrophy in vivo. Crucially, Md5BAC ΔmeqΔpp38 confers superior protection against highly virulent virus compared with a commercial vaccine strain, CVI988/Rispens. Transcriptomic profiling indicated that Md5BAC ΔmeqΔpp38 induced a different host immune response from CVI988/Rispens. In summary, a novel, effective, and safe vaccine candidate for prevention and control of MD caused by highly virulent MDV is reported. IMPORTANCE MDV is a highly contagious immunosuppressive and neoplastic pathogen. The virus can be controlled through vaccination via an attenuated meq deletion mutant virus that retains the ability to induce lymphoid organ atrophy. In this study, we overcame the deficiency by generating meq and pp38 double deletion mutant virus. Indeed, the successfully generated meq and pp38 double deletion mutant virus had significantly reduced replication capacity in vivo but not in vitro. It was fully attenuated and conferred superior protection efficacy against very virulent MDV challenge. In addition, the possible immunological protective mechanism of the double deletion mutant virus was shown to be different from that of the gold standard MDV vaccine, CVI988/Rispens. Overall, we successfully generated an attenuated meq deletion mutant virus and widened the range of potential vaccine candidates. Importantly, this study provides for the first time the theoretical basis of vaccination induced by fully attenuated gene-deletion mutant virus.
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Herpesvirus Gallináceo 2 , Vacunas contra la Enfermedad de Marek , Enfermedad de Marek , Proteínas Oncogénicas Virales , Enfermedades de las Aves de Corral , Animales , Enfermedad de Marek/prevención & control , Enfermedad de Marek/genética , Eliminación de Gen , Proteínas Oncogénicas Virales/genética , Pollos , Herpesvirus Gallináceo 2/genética , Vacunas contra la Enfermedad de Marek/genética , AtrofiaRESUMEN
Epstein-Barr virus (EBV) persists in human cells as episomes. EBV episomes are chromatinized and their 3D conformation varies greatly in cells expressing different latency genes. We used HiChIP, an assay which combines genome-wide chromatin conformation capture followed by deep sequencing (Hi-C) and chromatin immunoprecipitation (ChIP), to interrogate the EBV episome 3D conformation in different cancer cell lines. In an EBV-transformed lymphoblastoid cell line (LCL) GM12878 expressing type III EBV latency genes, abundant genomic interactions were identified by H3K27ac HiChIP. A strong enhancer was located near the BILF2 gene and looped to multiple genes around BALFs loci. Perturbation of the BILF2 enhancer by CRISPR interference (CRISPRi) and CRISPR activation (CRISPRa) altered the expression of BILF2 enhancer-linked genes, including BARF0 and BALF2, suggesting that this enhancer regulates the expression of linked genes. H3K27ac ChIP followed by deep sequencing (ChIP-seq) identified several strong EBV enhancers in T/NK (natural killer) lymphoma cells that express type II EBV latency genes. Extensive intragenomic interactions were also found which linked enhancers to target genes. A strong enhancer at BILF2 also looped to the BALF loci. CRISPRi also validated the functional connection between BILF2 enhancer and BARF1 gene. In contrast, H3K27ac HiChIP found significantly fewer intragenomic interactions in type I EBV latency gene-expressing primary effusion lymphoma (PEL) cell lines. These data provided new insight into the regulation of EBV latency gene expression in different EBV-associated tumors. IMPORTANCE EBV is the first human DNA tumor virus identified, discovered over 50 years ago. EBV causes ~200,000 cases of various cancers each year. EBV-encoded oncogenes, noncoding RNAs, and microRNAs (miRNAs) can promote cell growth and survival and suppress senescence. Regulation of EBV gene expression is very complex. The viral C promoter regulates the expression of all EBV nuclear antigens (EBNAs), some of which are very far away from the C promoter. Another way by which the virus activates remote gene expression is through DNA looping. In this study, we describe the viral genome looping patterns in various EBV-associated cancer cell lines and identify important EBV enhancers in these cells. This study also identified novel opportunities to perturb and eventually control EBV gene expression in these cancer cells.
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Infecciones por Virus de Epstein-Barr , Herpesvirus Humano 4 , Plásmidos , Latencia del Virus , Línea Celular Tumoral , Elementos de Facilitación Genéticos/genética , Infecciones por Virus de Epstein-Barr/genética , Infecciones por Virus de Epstein-Barr/virología , Antígenos Nucleares del Virus de Epstein-Barr/genética , Herpesvirus Humano 4/genética , Humanos , MicroARNs/metabolismo , Neoplasias/virología , Plásmidos/química , Plásmidos/genética , Plásmidos/metabolismo , Proteínas Virales/genética , Latencia del Virus/genéticaRESUMEN
The local coordination environment around the active centers has a major impact on tuning the intrinsic activity of M-N-C catalysts. Herein, a porous graphene with Fe-N5 active sites modified with Fe clusters is successfully fabricated by using Fe3+-SCN- and NaHCO3 as the metal precursor and pore-forming agent, respectively. The unique Fe-N5 configuration accompanying Fe clusters and the improved ORR activity are confirmed by various characterization techniques and theoretical calculations. Benefiting from the pores, mass and electron transfer channels are successfully constructed, making more active sites accessible and facilitating the ORR process. As a consequence, the as-prepared catalyst has an excellent ORR activity with a half-wave potential of 0.89 V, comparable selectivity, and superior stability. In addition, a homemade primary zinc-air battery using this material as the cathode catalyst has a maximum power density of 0.205 W/cm2, revealing the potential of the as-constructed CSA-Fe-N-C catalyst to replace precious Pt catalysts.
RESUMEN
Marek's disease (MD) is a neoplastic disease of chickens caused by an avian alphaherpesvirus, Marek's disease virus (MDV, also known as Gallid alphaherpesvirus 2 [GaHV2]). A total of 14 microRNA (miRNA) precursors and 26 mature miRNAs have been identified in MDV genome, which were grouped in three distinct clusters. In recent years, our studies revealed the role of MDV encoded cluster 3 miRNAs (or miR-M8-M10) and the specific function of its three members, miR-M6, miR-M7 and miR-M10, in regulating MDV replication and pathogenesis. In this study, we characterized the unique function of the other two members, miR-M8 and miR-M13, in cluster 3 miRNAs. Our results show that miR-M8 and miR-M13 are not important for MDV plaque formation and genome replication in vitro. Animal experiment results show that deletion of miR-M8-5p and miR-M13-5p eliminates the bursa atrophy, but not thymus atrophy, of MDV inoculated chickens. In addition, we found that the survival curve and MD incidences were not affected by disruption of miR-M8 and miR-M13. Taken together, this study uncovers the unique role of miR-M8 and miR-M13 in MDV replication and pathogenesis, which filled the gap in the research of MDV encoded miRNAs.
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Herpesvirus Gallináceo 2 , Enfermedad de Marek , MicroARNs , Animales , Atrofia/veterinaria , Pollos , Herpesvirus Gallináceo 2/genética , MicroARNs/genéticaRESUMEN
Chicken infectious anemia (CIA) is an immunosuppressive disease caused by the chicken infectious anemia virus (CIAV) resulting in heavy economic losses once an outbreak is established. This study conducted a systematic analysis of the epidemiology and pathology of CIA in Henan province, China. A total of 437 clinical tissue samples and 120 poultry disease-related live attenuated vaccines were collected during 2017-2020; of which 45 were positive for CIAV nucleic acid, with a positive rate of 8.08%. Our results showed that genome sequence similarity among a total of 12 CIAV isolates was high, and ranged from 97.1 to 99.3%, and their similarity to the vaccine strains Cux-1 and Del-Ros ranged from 97.8 to 98.6%. However, There were mutations in the locus of the major capsid proteins VP1, VP2, and VP3 among all isolates. The subsequent sequence analysis indicated that the isolates of HN-4 and HN-8 showed genetic recombination and follow up animal experiments revealed that HN-4 might be a pathogenic strain. Our results reveal that both field infection and non-CIAV vaccines contamination promote the epidemiology of CIAV in China and some dominant epidemic viruses have undergone recombination and evolution. This study provides important information to help with the prevention and control of CIAV in the poultry industry.
RESUMEN
Deoxyuridine 5'-triphosphate nucleotidohydrolase (dUTPase) of African swine fever virus (ASFV) is an essential enzyme required for efficient virus replication. Previous crystallography data have indicated that dUTPase (E165R) may serve as a therapeutic target for inhibiting ASFV replication; however, the specificity of the targeting site(s) in ASFV dUTPase remains unclear. In this study, 19 mouse monoclonal antibodies (mAbs) were produced, in which four mAbs showed inhibitory reactivity against E165R recombinant protein. Epitope mapping studies indicated that E165R has three major antigenic regions: 100-120 aa, 120-140 aa, and 140-165 aa. Three mAbs inhibited the dUTPase activity of E165R by binding to the highly conserved 149-RGEGRFGSTG-158 amino acid sequence. Interestingly, 8F6 mAb specifically recognized ASFV dUTPase but not Sus scrofa dUTPase, which may be due to structural differences in the amino acids of F151, R153, and F154 in the motif V region. In summary, we developed anti-E165R-specific mAbs, and identified an important antibody-binding antigenic epitope in the motif V of ASFV dUTPase. Our study provides a comprehensive analysis of mAbs that target the antigenic epitope of ASFV dUTPase, which may contribute to the development of novel antibody-based ASFV therapeutics.
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Virus de la Fiebre Porcina Africana/genética , Virus de la Fiebre Porcina Africana/inmunología , Anticuerpos Monoclonales/inmunología , Epítopos/aislamiento & purificación , Pirofosfatasas/genética , Fiebre Porcina Africana/virología , Secuencia de Aminoácidos , Animales , Anticuerpos Antivirales/inmunología , Antígenos Virales/inmunología , Mapeo Epitopo , Epítopos/genética , Proteínas Recombinantes , Porcinos , Replicación ViralRESUMEN
MicroRNAs (miRNAs) are a class of approximately 22 nucleotides long non-coding RNAs, and virus-encoded miRNAs play an important role in pathogenesis. Marek's disease virus (MDV) is an oncogenic avian alphaherpesvirus that causes immunosuppression and tumors in its natural host, chicken. In the MDV genome, 14 miRNA precursors and 26 mature miRNAs were identified, thus MDV has been used as a model to study the function of viral miRNAs in vivo. Recently, a cluster of miRNAs encoded by MDV, Cluster 3 miRNAs (miR-M8-M10), has been shown to restrict early cytolytic replication and pathogenesis of MDV. In this study, we further analyzed the role of miR-M6 and miR-M10, members of cluster miR-M8-M10, in MDV replication and pathogenicity. We found that, compared to parental MDV, deletion of miR-M6-5p significantly enhanced the replication of MDV in cell culture, but not in chickens. The replication of miR-M6-5p deletion MDV was restored once the deleted sequences were re-inserted. Our results also showed that deletion of miR-M10-5p did not affect the replication of MDV in vitro and in vivo. In addition, our animal study results showed that deletion of miR-M6-5p or miR-M10-5p did not alter the pathogenesis of MDV. In conclusion, our study shows that both miR-M6 and miR-M10 are dispensable for MDV replication and pathogenesis in chickens, while also suggests a repressive role of miR-M6 in MDV replication in cell culture.
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Herpesvirus Gallináceo 2 , Enfermedad de Marek , MicroARNs , Replicación Viral , Animales , Células Cultivadas , Pollos , Herpesvirus Gallináceo 2/genética , Enfermedad de Marek/fisiopatología , Enfermedad de Marek/virología , MicroARNs/genética , MicroARNs/metabolismo , Replicación Viral/genéticaRESUMEN
Herpesviruses are a group of double-strand DNA viruses that infect a wide range of hosts, including humans and animals. In the past decades, numerous methods have been developed to manipulate herpesviruses genomes, from the introduction of random mutations to specific genome editing. The development of genome manipulation methods has largely advanced the study of viral genes function, contributing not only to the understanding of herpesvirus biology and pathogenesis, but also the generation of novel vaccines and therapies to control and treat diseases. In this review, we summarize the major methods of herpesvirus genome manipulation with emphasis in their application to Marek's disease virus research.
RESUMEN
Marek's disease virus (MDV) is an oncogenic avian alphaherpesvirus whose genome consists of unique long (UL) and short (US) regions that are flanked by inverted repeat regions. More than 100 open reading frames (ORFs) have been annotated in the MDV genome, and are involved in various aspects of MDV biology and pathogenesis. Within UL and US regions of MDV, there are several unique ORFs, some of which have recently been shown to be important for MDV replication and pathogenesis. In this review, we will summarize the current knowledge on these ORFs and compare their location in different MDV strains.
Asunto(s)
Pollos/virología , ADN Viral/genética , Genoma Viral , Herpesvirus Gallináceo 2/genética , Enfermedad de Marek/virología , Sistemas de Lectura Abierta , Animales , Proteínas Virales/genética , Replicación ViralRESUMEN
Urea oxidation reaction (UOR) has been proposed to replace the formidable oxygen evolution reaction (OER) to reduce the energy consumption for producing hydrogen from electrolysis of water owing to its much lower thermodynamic oxidation potential compared to that of the OER. Therefore, exploring a highly efficient and stable hydrogen evolution and urea electrooxidation bifunctional catalyst is the key to achieve economical and efficient hydrogen production. In this paper, we report a heterostructured sulfide/phosphide catalyst (Ni3S2-Ni3P/NF) synthesized via one-step thermal treatment of Ni(OH)2/NF, which allows the simultaneous occurrence of phosphorization and sulfuration. The obtained Ni3S2-Ni3P/NF catalyst shows a sheet structure with an average sheet thickness of â¼100 nm, and this sheet is composed of interconnected Ni3S2 and Ni3P nanoparticles (â¼20 nm), between which there are a large number of accessible interfaces of Ni3S2-Ni3P. Thus, the Ni3S2-Ni3P/NF exhibits superior performance for both UOR and hydrogen evolution reaction (HER). For the overall urea-water electrolysis, to achieve current densities of 10 and 100 mA cm-2, cell voltage of only 1.43 and 1.65 V is required using this catalyst as both the anode and the cathode. Moreover, this catalyst also maintains fairly excellent stability after a long-term testing, indicating its potential for efficient and energy-saving hydrogen production. The theoretical calculation results show that the Ni atoms at the interface are the most efficient catalytically active site for the HER, and the free energy of hydrogen adsorption is closest to thermal neutrality, which is only 0.16 eV. A self-driven electron transfer at the interface, making the Ni3S2 sides become electron donating while Ni3P sides become electron withdrawing, may be the reason for the enhancement of the UOR activity. Therefore, this work shows an easy treatment for enhancing the catalytic activity of Ni-based materials to achieve high-efficiency urea-water electrolysis.