Dysregulation of RNA Pol activity at CTCF binding sites in EBV LCL ΔCTCF mutant
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE211247 | GEO | 2023/01/06
REPOSITORIES: GEO
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Project description:Epstein-Barr virus (EBV) is a ubiquitous human pathogen that is etiologically linked to several cancers and has been connected to multiple sclerosis. EBV persists in its human hosts through a biphasic replication cycle that depends on three latency stages. Understanding the host mechanisms that contribute to the tight regulation of viral gene expression in the discrete states of latency III, latency II, and latency I is important for developing therapeutic approaches for treating EBV positive cancers. Regulation of the chromatin structure of the EBV genome by cohesin and CTCF plays a role in this latency type switching. However, the function of the cohesin release factor WAPL had not previously been understood. In this study, we employ RNA-seq combined with immunofluorescence analysis to determine that the cohesin release factor WAPL plays a role specifically in inhibiting the expression of the oncogenic latent membrane proteins LMP-1 and LMP-2A. Through a combination of Hi-ChIP and ChIP-qPCR, we uncover that WAPL loss alters the looping interactions within the EBV genome and alters the histone modifications present at the LMP promoter. We propose that EBV coopts WAPL to maintain a latency I state and, without WAPL, leaky expression of the LMP proteins occurs.
2024-08-06 | GSE248336 | GEO
Project description:Epstein-Barr virus (EBV) is a ubiquitous human pathogen that is etiologically linked to several cancers and has been connected to multiple sclerosis. EBV persists in its human hosts through a biphasic replication cycle that depends on three latency stages. Understanding the host mechanisms that contribute to the tight regulation of viral gene expression in the discrete states of latency III, latency II, and latency I is important for developing therapeutic approaches for treating EBV positive cancers. Regulation of the chromatin structure of the EBV genome by cohesin and CTCF plays a role in this latency type switching. However, the function of the cohesin release factor WAPL had not previously been understood. In this study, we employ RNA-seq combined with immunofluorescence analysis to determine that the cohesin release factor WAPL plays a role specifically in inhibiting the expression of the oncogenic latent membrane proteins LMP-1 and LMP-2A. Through a combination of Hi-ChIP and ChIP-qPCR, we uncover that WAPL loss alters the looping interactions within the EBV genome and alters the histone modifications present at the LMP promoter. We propose that EBV coopts WAPL to maintain a latency I state and, without WAPL, leaky expression of the LMP proteins occurs.
2024-08-06 | GSE248335 | GEO
Project description:Epstein-Barr virus (EBV) is a ubiquitous human pathogen that is etiologically linked to several cancers and has been connected to multiple sclerosis. EBV employs a series of latency programs, including latency III, latency II, and latency I, to persistently colonize the B-cell compartment. Each of these programs is associated with human malignancies. However, our understanding remains incomplete of how these distinct latency programs are epigenetically restricted. While regulation of the chromatin structure of the EBV genome by cohesin and CTCF contributes to genome regulation, the function of the cohesin release factor Wings Apart-Like Protein Homolog (WAPL) had not previously been understood. In this study, we employ RNA-seq combined with immunofluorescence analysis to determine that loss of WAPL leads to aberrant expression of the oncogenic latent membrane proteins LMP1 and LMP2A in latency I Burkitt lymphoma cells. Through a combination of Hi-C, Hi-ChIP, and ChIP-qPCR, we uncover that WAPL loss causes alterations in looping across the EBV genome and specifically induces formation of loops between the LMP promoter and the oriLyt enhancers. We propose that EBV coopts WAPL to maintain a strict latency I state and, without WAPL, leaky expression of the LMP proteins occurs.
2024-08-06 | GSE264502 | GEO
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
2019-06-04 | GSE132138 | GEO
Project description:Epstein Barr Virus (EBV) is a potentially oncogenic gammaherpesvirus that establishes a chronic, latent infection in memory B cells. The EBV genome persists in infected host cells as a chromatinized episome and is subject to chromatin-mediated regulation. Binding of the host insulator protein CTCF to the EBV genome has an established role in maintaining viral latency type. CTCF is post-translationally modified by the host enzyme PARP1. PARP1, or Poly(ADP-ribose) polymerase 1, catalyzes the transfer of a poly(ADP-ribose) (PAR) moiety from NAD+ onto acceptor proteins including itself, histone proteins, and CTCF. PARylation of CTCF by PARP1 can affect CTCF’s insulator activity, DNA binding capacity, and ability to form chromatin loops. Both PARP1 and CTCF have been implicated in the regulation of EBV latency and lytic reactivation. Thus, we predicted that pharmacological inhibition with PARP1 inhibitors would affect EBV latency type through a chromatin-specific mechanism. Here, we show that PARP1 and CTCF colocalize at specific sites throughout the EBV genome, and provide evidence to suggest that PARP1 acts to stabilize CTCF binding and maintain the open chromatin landscape at the active Cp promoter during type III latency. Further, PARP1 activity is important in maintaining latency type-specific viral gene expression. The data presented here provide a rationale for the use of PARP inhibitors in the treatment of EBV-associated cancers exhibiting type III latency, and could ultimately contribute to an EBV-specific treatment strategy for AIDS-related or post-transplant lymphomas.
2018-06-27 | GSE115829 | GEO
Project description:Kaposi’s sarcoma-associated herpesvirus (KSHV) is the etiologic agent of primary effusion lymphoma (PEL). All PEL cell lines are infected with KSHV, and 70% are co-infected with Epstein-Barr Virus (EBV). KSHV reactivation from latency requires promoter-specific transactivation by the KSHV Rta protein through interactions with RBP-Jk (CSL), the cellular DNA binding component of the Notch signal transduction pathway. EBV transformation of primary B cells requires EBV nuclear antigen (EBNA)-2 to interact with RBP-Jk to direct the latent viral and cellular gene expression program. Although KSHV Rta and EBV EBNA-2 both require RBP-Jk for transactivation, previous studies have suggested that RBP-Jk-dependent transactivators do not function identically. We have found that the EBV latent protein LMP-1 is expressed in less than 5% of KSHV+/EBV+ PEL cells, but is induced in an Rta-dependent fashion when KSHV reactivates. KSHV Rta transactivates the EBV latency promoters in an RBP-Jk-dependent fashion and forms a ternary complex with RBP-Jk on the promoters. In B cells that are conditionally transformed by EBV alone, we show that KSHV Rta complements a short-term EBNA2 growth deficiency in an autocrine/paracrine manner. Complementaton of EBNA2-deficiency by Rta depends on RBP-Jk and LMP-1, and Rta transactivation is required for optimal growth of KSHV+/EBV+ PEL lines. Our data suggest that Rta can contribute to EBV-driven cellular growth by transactivating RBP-Jk-dependent EBV latency genes. However, our data also suggest that EBNA2 and Rta induce distinct alterations in the cellular proteomes that contribute to growth of infected cells.
2010-12-31 | GSE21375 | GEO
Project description:Epstein-Barr virus (EBV) establishes lifelong asymptomatic infection by replication of its chromatinized episomes with the host genome. EBV exhibits different latency-associated transcriptional repertoires, each with distinct three-dimensional structures. CTCF, Cohesin and PARP1 are involved in maintaining viral latency and establishing episome architecture. Epstein-Barr virus-associated gastric cancer (EBVaGC) represents 1.3% to 30.9% of all gastric cancers globally. EBV-positive gastric cancers exhibit an intermediate viral transcription profile known as "Latency II", expressing specific viral genes and noncoding RNAs. In this study, we investigated the impact of PARP1 inhibition on CTCF/Cohesin binding in Type II latency. We observed destabilization of the binding of both factors, leading to a disrupted three-dimensional architecture of the episomes and an altered viral gene expression. Despite sharing the same CTCF binding profile, Type I, II, and III latencies exhibit different 3D structures that correlate with variations in viral gene expression. Additionally, our analysis of H3K27ac-enriched interactions revealed differences between Type II latency episomes and a link to cellular transformation through docking of the EBV genome at specific sites of the Human genome, thus promoting oncogene expression. Overall, this work provides insights into the role of PARP1 in maintaining active latency and novel mechanisms of EBV-induced cellular transformation.
2023-10-11 | GSE239987 | GEO
Project description:Epstein-Barr virus (EBV) establishes lifelong asymptomatic infection by replication of its chromatinized episomes with the host genome. EBV exhibits different latency-associated transcriptional repertoires, each with distinct three-dimensional structures. CTCF, Cohesin and PARP1 are involved in maintaining viral latency and establishing episome architecture. Epstein-Barr virus-associated gastric cancer (EBVaGC) represents 1.3% to 30.9% of all gastric cancers globally. EBV-positive gastric cancers exhibit an intermediate viral transcription profile known as "Latency II", expressing specific viral genes and noncoding RNAs. In this study, we investigated the impact of PARP1 inhibition on CTCF/Cohesin binding in Type II latency. We observed destabilization of the binding of both factors, leading to a disrupted three-dimensional architecture of the episomes and an altered viral gene expression. Despite sharing the same CTCF binding profile, Type I, II, and III latencies exhibit different 3D structures that correlate with variations in viral gene expression. Additionally, our analysis of H3K27ac-enriched interactions revealed differences between Type II latency episomes and a link to cellular transformation through docking of the EBV genome at specific sites of the Human genome, thus promoting oncogene expression. Overall, this work provides insights into the role of PARP1 in maintaining active latency and novel mechanisms of EBV-induced cellular transformation.
2023-10-11 | GSE239994 | GEO
Project description:Epstein-Barr virus (EBV) establishes lifelong asymptomatic infection by replication of its chromatinized episomes with the host genome. EBV exhibits different latency-associated transcriptional repertoires, each with distinct three-dimensional structures. CTCF, Cohesin and PARP1 are involved in maintaining viral latency and establishing episome architecture. Epstein-Barr virus-associated gastric cancer (EBVaGC) represents 1.3% to 30.9% of all gastric cancers globally. EBV-positive gastric cancers exhibit an intermediate viral transcription profile known as "Latency II", expressing specific viral genes and noncoding RNAs. In this study, we investigated the impact of PARP1 inhibition on CTCF/Cohesin binding in Type II latency. We observed destabilization of the binding of both factors, leading to a disrupted three-dimensional architecture of the episomes and an altered viral gene expression. Despite sharing the same CTCF binding profile, Type I, II, and III latencies exhibit different 3D structures that correlate with variations in viral gene expression. Additionally, our analysis of H3K27ac-enriched interactions revealed differences between Type II latency episomes and a link to cellular transformation through docking of the EBV genome at specific sites of the Human genome, thus promoting oncogene expression. Overall, this work provides insights into the role of PARP1 in maintaining active latency and novel mechanisms of EBV-induced cellular transformation.
2023-10-11 | GSE239992 | GEO
Project description:Epstein-Barr virus (EBV) establishes lifelong asymptomatic infection by replication of its chromatinized episomes with the host genome. EBV exhibits different latency-associated transcriptional repertoires, each with distinct three-dimensional structures. CTCF, Cohesin and PARP1 are involved in maintaining viral latency and establishing episome architecture. Epstein-Barr virus-associated gastric cancer (EBVaGC) represents 1.3% to 30.9% of all gastric cancers globally. EBV-positive gastric cancers exhibit an intermediate viral transcription profile known as "Latency II", expressing specific viral genes and noncoding RNAs. In this study, we investigated the impact of PARP1 inhibition on CTCF/Cohesin binding in Type II latency. We observed destabilization of the binding of both factors, leading to a disrupted three-dimensional architecture of the episomes and an altered viral gene expression. Despite sharing the same CTCF binding profile, Type I, II, and III latencies exhibit different 3D structures that correlate with variations in viral gene expression. Additionally, our analysis of H3K27ac-enriched interactions revealed differences between Type II latency episomes and a link to cellular transformation through docking of the EBV genome at specific sites of the Human genome, thus promoting oncogene expression. Overall, this work provides insights into the role of PARP1 in maintaining active latency and novel mechanisms of EBV-induced cellular transformation.
2023-10-11 | GSE239989 | GEO