Project description:Our aim was to investigate the interaction between epidermal differentiation and VZV infection. By means of a calcium-induced keratinocyte differentiation model and RNA-seq we show VZV infection has a profound effect on differentiating keratinocytes and hijacks the normal process of epidermal gene expression to generate a signature resembling patterns of gene expression seen in both heritable and acquired skin-blistering disorders. Analysis of the viral transcriptome provides evidence that VZV replication in skin is tightly linked to differentiation and critically, that late viral gene expression is associated with cellular differentiation. The experiment was performed on human primary keratinocytes under four conditions: undifferentiated/uninfected, uninfected/differentiated, VZV-infected/undifferentiated and VZV-infected/differentiated.
Project description:The highly conserved herpesvirus glycoprotein complex, gB/gH-gL, mediates membrane fusion during virion entry and cell-cell fusion. Varicella-zoster virus (VZV) characteristically forms multi-nucleated cells, or syncytia, during the infection of human tissues but little is known about this process. The cytoplasmic domain of VZV gB (gBcyt) has been implicated in cell-cell fusion regulation because a gB[Y881F] substitution causes hyperfusion. The gBcyt regulation is necessary for VZV pathogenesis as the hyperfusogenic mutant gB[Y881F] is severely attenuated in human skin xenografts. In this study, gBcyt regulated fusion was investigated by comparing melanoma cells infected with wild type-like VZV or hyperfusogenic mutants. The gB[Y881F] mutant exhibited dramatically accelerated syncytia formation in melanoma cells caused by fusion of infected cells with many uninfected cells, increased cytoskeleton reorganization and rapid displacement of nuclei to dense central structures when compared to pOka using live cell confocal microscopy. VZV and human transcriptomes were concurrently investigated using RNA-seq to identify viral and cellular responses induced when the gBcyt regulation was disrupted by the gB[Y881F] substitution. The expression of four vital VZV genes, ORF61 and glycoproteins, gC, gE and gI, was significantly reduced at 36 hours post infection for the hyperfusogenic mutants. Importantly, hierarchical clustering demonstrated an association of differential gene expression with dysregulated gBcyt-mediated fusion. A subset of Ras GTPase genes linked to membrane remodeling were upregulated in cells infected with the hyperfusogenic mutants. These data implicate the gBcyt in the regulation gB fusion function that, if unmodulated, triggers cellular processes leading to hyperfusion that attenuates VZV infection.
Project description:Sequence analyses shown that most exons of VZV circVLTs were overlapped with ORFs, except for exon5, which was an ideal mutation position. Using a galK positive/counter selection VZV bacteria artificial chromosome (BAC) system, we replaced upstream (104,765-104,785 Mutation2, pOKA-M2) or downstream (104,785-104,805, Mutation1, pOKA-M1) of circVLTs BSJ exon5 with 20 bp random sequences in VZV genomic DNA level. The code used in this study and extended data are available from the GitHub repository (https://github.com/ShaominYang/VZV_circRNA)
Project description:Varicella Zoster Virus (VZV) is a skin-tropic virus that infects epidermal keratinocytes and causes chickenpox. Although common, VZV infection can be life-threatening particularly in the immunocompromised. Therefore, understanding VZV-keratinocyte interactions is important to find new treatments beyond vaccination and anti-viral drugs. In VZV- infected skin, Kallikrein 6 (KLK6), and the ubiquitin-ligase MDM2 are up-regulated concomitant with Keratin 10 (K10) down-regulation. MDM2 binds to K10 targeting it for degradation via the ubiquitin-proteasome pathway. Preventing K10 degradation reduced VZV propagation in culture and prevented epidermal disruption in skin explants. K10 knockdown induced expression of the nuclear receptor subfamily 4, group A, member 1 (NR4A1) and enhanced viral propagation in culture. NR4A1 knockdown prevented viral propagation in culture, reduced LC3 levels and increased LAMP2 expression. We therefore describe a novel drug-able pathway whereby MDM2 ubiquitinates and degrades K10 increasing NR4A1 expression allowing VZV replication and propagation.
Project description:Two wild house mice lines were genetically selected for short and long attack latency. Mice with an attack latency <50s or >600s were considered short attack latency mice (SAL) and long attack latency mice(LAL) respectively. RNA from the hippocampus of 14 SAL or 14 LAL mice was pooled and used as input material for the SAGE libraries. Keywords: other
Project description:Deciphering the molecular pathogenesis of virally induced cancers is challenging due, in part, to the heterogeneity of both viral and host gene expression. Epstein-Barr Virus (EBV) is a ubiquitous herpesvirus prevalent in B-cell lymphomas of the immune suppressed. EBV infection of primary human B cells leads to their immortalization into lymphoblastoid cell lines (LCLs) serving as a model of these lymphomas. In previous studies, our lab has described a temporal model for immortalization with an initial phase characterized by expression of the Epstein-Barr Nuclear Antigens (EBNAs), high c-Myc activity, and hyper-proliferation in the absence of the Latent Membrane Proteins (LMPs), called latency IIb. This is followed by the long-term outgrowth of LCLs expressing the EBNAs along with the LMPs, particularly the NFkB-activating LMP1, defining latency III. LCLs, however, express a broad distribution of LMP1 such that a subset of these cells expresses LMP1 at levels seen in latency IIb, making it difficult to distinguish these two latency states. In this study, we performed mRNA-Seq on early EBV-infected latency IIb cells and latency III LCLs sorted by NFkB activity. We found that latency IIb transcriptomes clustered independently from latency III independent of NFkB. We identified and validated mRNAs defining these latency states. Indeed, we were able to distinguish latency IIb cells from LCLs expressing low levels of LMP1 using multiplex RNA-FISH targeting EBV EBNA2, LMP1, and human CCR7 or MGST1. This study defines latency IIb as a bona fide latency state independent from latency III and identifies biomarkers for understanding EBV-associated tumor heterogeneity