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Marek's disease virus (MDV) encodes a basic-leucine zipper (BZIP) protein, Meq, which is considered the major MDV oncoprotein. It has been reported that the oncogenicity of Meq is associated with its interaction with C-terminal binding protein 1 (CtBP), which is also an interaction partner of Epstein-Barr virus encoded EBNA3A and EBNA3C oncoproteins. Since both EBNA3C and CtBP interact with histone deacetylase 1 (HDAC1) and HDAC2, we examined whether Meq shares this interaction with chicken HDAC1 (chHDAC1) and chHDAC2. Using confocal microscopy analysis, we show that Meq co-localizes with chHDAC1 and chHDAC2 in the nuclei of MDV lymphoblastoid tumor cells. In addition, immunoprecipitation assays demonstrate that Meq interacts with chHDAC1 and chHDAC2 in transfected cells and MDV lymphoblastoid tumor cells. Using deletion mutants, interaction domains were mapped to the N-terminal dimerization domain of chHDAC1 and chHDAC2, and the BZIP domain of Meq. Our results further demonstrate that this interaction mediates the degradation of chHDAC1 and chHDAC2 via the proteasome dependent pathway. In addition, our results show that Meq also induces the reduction of global ubiquitinated proteins through a proteasome dependent pathway. In conclusion, our results provide evidence that Meq interacts with chHDAC1 and chHDAC2, and induces their proteasome dependent degradation.

Marek's disease (MD) is a neoplastic disease of chickens caused by Marek's disease virus (MDV), a member of the subfamily Alphaherpesvirinae Like other alphaherpesviruses, MDV encodes a serine/threonine protein kinase, US3. The functions of US3 have been extensively studied in other alphaherpesviruses; however, the biological functions of MDV US3 and its substrates have not been studied in detail. In this study, we investigated potential cellular pathways that are regulated by MDV US3 and identified chicken CREB (chCREB) as a substrate of MDV US3. We show that wild-type MDV US3, but not kinase-dead US3 (US3-K220A), increases CREB phosphorylation, leading to recruitment of phospho-CREB (pCREB) to the promoter of the CREB-responsive gene and activation of CREB target gene expression. Using US3 deletion and US3 kinase-dead recombinant MDV, we identified US3-responsive MDV genes during infection and found that the majority of US3-responsive genes were located in the MDV repeat regions. Chromatin immunoprecipitation sequencing (ChIP-seq) studies determined that some US3-regulated genes colocalized with Meq (an MDV-encoded oncoprotein) recruitment sites. Chromatin immunoprecipitation-PCR (ChIP-PCR) further confirmed Meq binding to the ICP4/LAT region, which is also regulated by US3. Furthermore, biochemical studies demonstrated that MDV US3 interacts with Meq in transfected cells and MDV-infected chicken embryonic fibroblasts in a phosphorylation-dependent manner. Finally, in vitro kinase studies revealed that Meq is a US3 substrate. MDV US3 thus acts as an upstream kinase of the CREB signaling pathway to regulate the transcription function of the CREB/Meq heterodimer, which targets cellular and viral gene expression.IMPORTANCE MDV is a potent oncogenic herpesvirus that induces T-cell lymphoma in infected chickens. Marek's disease continues to have a significant economic impact on the poultry industry worldwide. US3 encoded by alphaherpesviruses is a multifunctional kinase involved in the regulation of various cellular pathways. Using an MDV genome quantitative reverse transcriptase PCR (qRT-PCR) array and chromatin immunoprecipitation, we elucidated the role of MDV US3 in viral and cellular gene regulation. Our results provide insights into how viral kinase regulates host cell signaling pathways to activate both viral and host gene expression. This is an important step toward understanding host-pathogen interaction through activation of signaling cascades.

Vaccine‐based therapeutics for cancers face several challenges including lack of immunogenicity and tumor escape pathways for single antigen targets. It has been reported that radiotherapy has an in situ vaccine effect that provides tumor antigens following irradiation, helping to activate antigen‐presenting cells (APCs). Herein, a new vaccine approach is developed by combining genetically engineered irradiated tumor cell debris (RTD) and hyaluronic acid (HA), termed HA@RTD. A cancer cell line is developed that overexpresses granulocyte‐macrophage colony‐stimulating factor (GM‐CSF). A hydrogel was developed by covalent conjugation of HA with RTD proteins that acted as a potent vaccine system, the effects which were probed with T cell receptor sequencing. The engineered vaccine activated antitumor immunity responses and prevented tumor growth in mice even with a single immunization. HA@RTD vaccine efficacy was also assessed in therapeutic settings with established tumors and in combination with immune checkpoint blockade. [ABSTRACT FROM AUTHOR]

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. Author summary: A longstanding question has remained how Epstein-Barr virus (EBV) epigenetically switches between latency programs as it navigates the B-cell compartment. EBV uses its latency III program to stimulate newly infected B cell growth and then trafficking into secondary lymphoid tissue germinal centers (GCs). In latency III, the viral C promoter stimulates expression of six Epstein-Barr nuclear antigens (EBNA) that in turn induce two latent membrane proteins (LMP). However, knowledge has remained incomplete about how GC microenvironmental cues trigger switching to latency II, where only one EBNA and two LMP are expressed, a program observed in Hodgkin lymphoma. Building on prior evidence that GC cytokines are a major cue, we systematically tested effects of cytokines secreted by GC-resident T follicular helper and follicular dendritic cells on EBV latency gene expression and on epigenetic remodeling of their promoters. This highlighted that a range of GC cytokines repress latency III EBNA, while only several support LMP1 expression, major events in the transition between the latency III and II programs. We identified key downstream roles of JAK/STAT signaling in relaying cytokine signals to the EBV epigenome, including obligatory STAT3 and 5 roles in rewiring of C and LMP promoter histone epigenetic marks. [ABSTRACT FROM AUTHOR]

To evaluate the effect and toxicity of alprostadil combined with thioctic acid injection in the treatment of patients with diabetic nephropathy (DN).

The near-surface structure of the Pt-based alloy including the surface and subsurface structures is prominent to their electrocatalytic performance. Modulating the near-surface structure of PtCo intermetallics with small particle size could efficiently optimize the binding force between Pt and oxygen and finally enhance its oxygen reduction reaction (ORR) performance. Here we simultaneously achieve the size controlling and surface modulation of intermetallic nanoparticles (NPs) in a weak-oxidative confined space with abundant uncoordinated oxygen atoms. 1–2 atomic layers of concave Pt-rich surface were successfully constructed on 4 nm L10-PtCo core after removing Co—O species which is derived from the segregation of the subsurface Co to the surface induced by the uncoordinated oxygen atoms. Owing to the elaborate structure, PtCo-1000/C catalyst shows significant improvement in both activity (1.290 A·mgPt−1 and 1.529 mA·cmPt−2 at 0.9 V vs. reversible hydrogen electrode (RHE)) and stability (85.2% of initial mass activity after accelerated degression tests (ADTs)) even the production is scaled up to gram level. Density functional theory calculations suggest that the cave Pt site optimizes the protonation of *O, which finally boosts the ORR performance. [ABSTRACT FROM AUTHOR]

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 (m6A) 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 m6A modification program during viral replication in vivo, especially in relation to key pathways involved in tumorigenesis. [ABSTRACT FROM AUTHOR]