Project description:Subpopulations of B-lymphocytes traffic to different sites and organs to provide diverse and tissue-specific functions. Here, we provide evidence that epigenetic differences confer a neuroinvasive phenotype. An EBV+ B cell lymphoma cell line (M14) with low frequency trafficking to the CNS was neuroadapted to generate a highly neuroinvasive B-cell population (MUN14). MUN14 B cells efficiently infiltrated the CNS within one week and produced neurological pathologies. We compared the gene expression profiles of viral and cellular genes using RNA-Seq and identified one viral (EBNA1) and several cellular gene candidates, including secreted phosphoprotein 1/osteopontin (SPP1/OPN), neuron navigator 3 (NAV3), CXCR4, and germinal center-associated signaling and motility protein (GCSAM)) that were selectively upregulated in MUN14. ATAC-Seq and ChIP-qPCR revealed that these gene expression changes correlated with epigenetic changes at gene regulatory elements. The neuroinvasive phenotype could be attenuated with a neutralizing antibody to OPN, confirming the functional role of this protein in trafficking EBV+ B cells to the CNS. These studies indicate that B-cell trafficking to the CNS can be acquired by epigenetic adaptations and provide a new model to study B-cell neuroinvasion associated CNS lymphoma and autoimmune disease of the CNS, including multiple sclerosis (MS).cell infection to investigate the underlying mechanisms that control EBV-induced B-cell immortalization. ATAC-seq revealed that over a third of accessible chromatin is altered with the most perturbed sites overlapping Ets-family, including PU.1 and RUNX1 transcription factors. EBV nuclear antigens (EBNAs) clustered with different gene categories and RNA-seq identified the transcriptional response of these gene. Focusing on EBNA1 revealed a selection of gene targets involved in nucleotide metabolism. Metabolomics indicated that adenosine and purine metabolism are significantly altered by EBV immortalization, and we validated that adenosine deaminase (ADA) is a direct and critical target of EBNA1 and the EBV-directed immortalization process. These findings reveal that purine metabolism and ADA inhibitors may be a useful therapeutic for EBV-driven lymphoid cancers
Project description:Subpopulations of B-lymphocytes traffic to different sites and organs to provide diverse and tissue-specific functions. Here, we provide evidence that epigenetic differences confer a neuroinvasive phenotype. An EBV+ B cell lymphoma cell line (M14) with low frequency trafficking to the CNS was neuroadapted to generate a highly neuroinvasive B-cell population (MUN14). MUN14 B cells efficiently infiltrated the CNS within one week and produced neurological pathologies. We compared the gene expression profiles of viral and cellular genes using RNA-Seq and identified one viral (EBNA1) and several cellular gene candidates, including secreted phosphoprotein 1/osteopontin (SPP1/OPN), neuron navigator 3 (NAV3), CXCR4, and germinal center-associated signaling and motility protein (GCSAM)) that were selectively upregulated in MUN14. ATAC-Seq and ChIP-qPCR revealed that these gene expression changes correlated with epigenetic changes at gene regulatory elements. The neuroinvasive phenotype could be attenuated with a neutralizing antibody to OPN, confirming the functional role of this protein in trafficking EBV+ B cells to the CNS. These studies indicate that B-cell trafficking to the CNS can be acquired by epigenetic adaptations and provide a new model to study B-cell neuroinvasion associated CNS lymphoma and autoimmune disease of the CNS, including multiple sclerosis (MS).cell infection to investigate the underlying mechanisms that control EBV-induced B-cell immortalization. ATAC-seq revealed that over a third of accessible chromatin is altered with the most perturbed sites overlapping Ets-family, including PU.1 and RUNX1 transcription factors. EBV nuclear antigens (EBNAs) clustered with different gene categories and RNA-seq identified the transcriptional response of these gene. Focusing on EBNA1 revealed a selection of gene targets involved in nucleotide metabolism. Metabolomics indicated that adenosine and purine metabolism are significantly altered by EBV immortalization, and we validated that adenosine deaminase (ADA) is a direct and critical target of EBNA1 and the EBV-directed immortalization process. These findings reveal that purine metabolism and ADA inhibitors may be a useful therapeutic for EBV-driven lymphoid cancers
Project description:Subpopulations of B-lymphocytes traffic to different sites and organs to provide diverse and tissue-specific functions. Here, we provide evidence that epigenetic differences confer a neuroinvasive phenotype. An EBV+ B cell lymphoma cell line (M14) with low frequency trafficking to the CNS was neuroadapted to generate a highly neuroinvasive B-cell population (MUN14). MUN14 B cells efficiently infiltrated the CNS within one week and produced neurological pathologies. We compared the gene expression profiles of viral and cellular genes using RNA-Seq and identified one viral (EBNA1) and several cellular gene candidates, including secreted phosphoprotein 1/osteopontin (SPP1/OPN), neuron navigator 3 (NAV3), CXCR4, and germinal center-associated signaling and motility protein (GCSAM) that were selectively upregulated in MUN14. ATAC-Seq and ChIP-qPCR revealed that these gene expression changes correlated with epigenetic changes at gene regulatory elements. The neuroinvasive phenotype could be attenuated with a neutralizing antibody to OPN, confirming the functional role of this protein in trafficking EBV+ B cells to the CNS. These studies indicate that B-cell trafficking to the CNS can be acquired by epigenetic adaptations and provide a new model to study B-cell neuroinvasion associated CNS lymphoma and autoimmune disease of the CNS, including multiple sclerosis (MS).
Project description:Most humans are infected with Epstein-Barr virus (EBV), a cancer-causing virus. While EBV generally persists silently in B lymphocytes, periodic lytic (re-)activation of latent virus is central to its life cycle and to most EBV-related diseases. However, a substantial fraction of EBV-infected B cells and tumor cells in a population is refractory to lytic activation. This resistance to lytic activation directly and profoundly impacts viral persistence and effectiveness of oncolytic therapy for EBV+ cancers. To identify the mechanisms that underlie susceptibility to EBV-lytic activation, we used host protein-expression profiling of separated-lytic and -refractory cells.
Project description:Most humans are infected with Epstein-Barr virus (EBV), a cancer-causing virus. While EBV generally persists silently in B lymphocytes, periodic lytic (re-)activation of latent virus is central to its life cycle and to most EBV-related diseases. However, a substantial fraction of EBV-infected B cells and tumor cells in a population is refractory to lytic activation. This resistance to lytic activation directly and profoundly impacts viral persistence and effectiveness of oncolytic therapy for EBV+ cancers. To identify the mechanisms that underlie susceptibility to EBV-lytic activation, we used host protein-expression profiling of separated-lytic and -refractory cells.
Project description:Immunodeficiency-related Epstein-Barr-virus-positive (EBV+) primary CNS lymphoma (PCNSL) represents a distinct clinical entity with an inferior prognosis compared to EBV--disease. Genetic alterations that drive EBV-related CNS lymphomagenesis remain unclear precluding targeted therapies. In this study, we performed whole-exome sequencing of 5 paired (tumor and germline control) and 13 unpaired (tumor only) EBV+ PCNSL as well as 2 EBV- controls.
Project description:Background: In several types of malignancies, especially EBV-associated nasopharyngeal carcinomas, high Galectin-9 (Gal-9) expression is indicative of an aggressive tumor phenotype. The contribution of Gal-9 to the oncogenesis of B-cell lymphomas (BCLs) has not yet been investigated. Methods: The expression of Gal-9, STING, and EBNA1 was measured by immunohistochemical (IHC) staining on tumor sections from 66 BCL patients. Artificial EBV infection of normal primary B cells in vitro was used as an experimental model. The dynamic changes of the transcriptome of EBV-infected B cells undergoing transformation were investigated by bulk RNA-sequencing and bioinformatics analysis. The oncogenic role of Gal-9 was investigated in vitro by addition of recombinant Gal-9 to EBV-infected primary B-cells, and growth assays. The underlying molecular mechanisms were investigated by immunoblotting and immunofluorescent (IF) staining, CHIP and luciferase reporter assays. Results: In clinical specimens of BCLs, Gal-9 expression was significantly associated with tumor stage, latent EBV infection and abundance of the viral latent protein EBNA1. Looking at the transcriptome changes occurring in vitro during EBV-driven B-cell transformation, we could identify a series of genes undergoing long term activation and remaining highly expressed in mature LCLs. The Gal-9 gene is one of them. Its expression is enhanced during the transformation process at the mRNA level and even more at the protein level. This up-regulation results at least in part from its transactivation by EBNA1 which can bind its promoter. Reciprocally, we find that addition of extra-cellular Gal-9 promotes B-cell transformation and establishment of the latent phase of EBV-infection. Concomitantly, extra-cellular Gal-9 blocks STING signaling and enhances STAT3 phosphorylation. Inhibition of Sting signaling or STAT3 phosphorylation blocks B-cell transformation, even in the presence of Gal-9. Conclusion: our data unveil a role of amplification and acceleration for Gal-9 in the process of EBV-driven B-cell transformation. This process might be relevant to the pathogenesis of EBV-associated BCLs.