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  1. Article ; Online: Cytomegalovirus Latency and Reactivation: An Intricate Interplay With the Host Immune Response.

    Forte, Eleonora / Zhang, Zheng / Thorp, Edward B / Hummel, Mary

    Frontiers in cellular and infection microbiology

    2020  Volume 10, Page(s) 130

    Abstract: CMV is an ancient herpesvirus that has co-evolved with its host over millions of years. The 236 kbp genome encodes at least 165 genes, four non-coding RNAs and 14 miRNAs. Of the protein-coding genes, 43-44 are core replication genes common to all ... ...

    Abstract CMV is an ancient herpesvirus that has co-evolved with its host over millions of years. The 236 kbp genome encodes at least 165 genes, four non-coding RNAs and 14 miRNAs. Of the protein-coding genes, 43-44 are core replication genes common to all herpesviruses, while ~30 are unique to betaherpesviruses. Many CMV genes are involved in evading detection by the host immune response, and others have roles in cell tropism. CMV replicates systemically, and thus, has adapted to various biological niches within the host. Different biological niches may place competing demands on the virus, such that genes that are favorable in some contexts are unfavorable in others. The outcome of infection is dependent on the cell type. In fibroblasts, the virus replicates lytically to produce infectious virus. In other cell types, such as myeloid progenitor cells, there is an initial burst of lytic gene expression, which is subsequently silenced through epigenetic repression, leading to establishment of latency. Latently infected monocytes disseminate the virus to various organs. Latency is established through cell type specific mechanisms of transcriptional silencing. In contrast, reactivation is triggered through pathways activated by inflammation, infection, and injury that are common to many cell types, as well as differentiation of myeloid cells to dendritic cells. Thus, CMV has evolved a complex relationship with the host immune response, in which it exploits cell type specific mechanisms of gene regulation to establish latency and to disseminate infection systemically, and also uses the inflammatory response to infection as an early warning system which allows the virus to escape from situations in which its survival is threatened, either by cellular damage or infection of the host with another pathogen. Spontaneous reactivation induced by cellular aging/damage may explain why extensive expression of lytic genes has been observed in recent studies using highly sensitive transcriptome analyses of cells from latently infected individuals. Recent studies with animal models highlight the potential for harnessing the host immune response to blunt cellular injury induced by organ transplantation, and thus, prevent reactivation of CMV and its sequelae.
    MeSH term(s) Animals ; Cytomegalovirus/genetics ; Gene Expression ; Humans ; Immunity ; Myeloid Cells ; Virus Activation ; Virus Latency
    Language English
    Publishing date 2020-03-31
    Publishing country Switzerland
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Review
    ZDB-ID 2619676-1
    ISSN 2235-2988 ; 2235-2988
    ISSN (online) 2235-2988
    ISSN 2235-2988
    DOI 10.3389/fcimb.2020.00130
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Critical Role for the Human Cytomegalovirus Major Immediate Early Proteins in Recruitment of RNA Polymerase II and H3K27Ac To an Enhancer-Like Element in Ori

    Forte, Eleonora / Li, Ming / Ayaloglu Butun, Fatma / Hu, Qiaolin / Borst, Eva Maria / Schipma, Matthew J / Piunti, Andrea / Shilatifard, Ali / Terhune, Scott S / Abecassis, Michael / Meier, Jeffery L / Hummel, Mary

    Microbiology spectrum

    2023  Volume 11, Issue 1, Page(s) e0314422

    Abstract: Human cytomegalovirus (HCMV) is an opportunistic pathogen that infects most of the population. The complex 236 kbp genome encodes more than 170 open reading frames, whose expression is temporally regulated by both viral transcriptional regulators and ... ...

    Abstract Human cytomegalovirus (HCMV) is an opportunistic pathogen that infects most of the population. The complex 236 kbp genome encodes more than 170 open reading frames, whose expression is temporally regulated by both viral transcriptional regulators and cellular factors that control chromatin and transcription. Here, we have used state of the art genomic technologies to investigate the viral transcriptome in conjunction with 2 key transcriptional regulators: Pol II and H3K27Ac. Although it is well known that the major immediate early (IE) proteins activate early gene expression through both direct and indirect interactions, and that histone modifications play an important role in regulating viral gene expression, the role of the IE proteins in modulating viral chromatin is not fully understood. To address this question, we have used a virus engineered for conditional expression of the IE proteins combined with RNA and Chromatin immunoprecipitation (ChIP) analyses to assess the role of these proteins in modulating both viral chromatin and gene expression. Our results show that (i) there is an enhancer-like element in Ori
    MeSH term(s) Humans ; Immediate-Early Proteins/genetics ; Cytomegalovirus/genetics ; RNA Polymerase II/genetics ; RNA Polymerase II/metabolism ; Viral Proteins/genetics ; Viral Proteins/metabolism ; Chromatin/genetics ; Gene Expression Regulation, Viral
    Chemical Substances Immediate-Early Proteins ; RNA Polymerase II (EC 2.7.7.-) ; Viral Proteins ; Chromatin
    Language English
    Publishing date 2023-01-16
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 2807133-5
    ISSN 2165-0497 ; 2165-0497
    ISSN (online) 2165-0497
    ISSN 2165-0497
    DOI 10.1128/spectrum.03144-22
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article: Epigenetic regulation of cellular and cytomegalovirus genes during myeloid cell development.

    Liu, Xue-Feng / Hummel, Mary / Abecassis, Michael

    Internal medicine review (Washington, D.C. : Online)

    2017  Volume 3, Issue 3

    Abstract: Myeloid cells are important cell types that carry human cytomegalovirus. Latent viral DNA is present in CD34+ progenitor cells and their derived monocytes. However, differentiation of latently infected monocytes to mature macrophages or dendritic cells ... ...

    Abstract Myeloid cells are important cell types that carry human cytomegalovirus. Latent viral DNA is present in CD34+ progenitor cells and their derived monocytes. However, differentiation of latently infected monocytes to mature macrophages or dendritic cells causes reactivation of latent viruses. During hematopoietic development, pluripotent genes are repressed, and lineage specific genes are activated in a step-wise manner. This process is governed by cell-type specific chromatin states. Enhancers in the hematopoietic system are highly dynamic and established by pioneer (first tier) transcription factors (TFs), which set the stage for second and third tier TF binding. In this review, we examine the epigenetic mechanisms that regulate myeloid cell development, cell identity, and activation with a special focus on factors that regulate viral gene expression and the status of viral infection in myeloid cells.
    Language English
    Publishing date 2017-03
    Publishing country United States
    Document type Journal Article
    ISSN 2470-3524
    ISSN 2470-3524
    DOI 10.18103/imr.v3i3.385
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: New Insights Into the Molecular Mechanisms and Immune Control of Cytomegalovirus Reactivation.

    Heald-Sargent, Taylor A / Forte, Eleonora / Liu, Xuefeng / Thorp, Edward B / Abecassis, Michael M / Zhang, Zheng Jenny / Hummel, Mary A

    Transplantation

    2020  Volume 104, Issue 5, Page(s) e118–e124

    Abstract: Cytomegalovirus (CMV) is a β-herpesvirus that establishes lifelong latency in infected hosts. Following transplantation of a latently infected organ, reactivation can occur and consists of a spectrum of clinically apparent syndromes from mild symptoms to ...

    Abstract Cytomegalovirus (CMV) is a β-herpesvirus that establishes lifelong latency in infected hosts. Following transplantation of a latently infected organ, reactivation can occur and consists of a spectrum of clinically apparent syndromes from mild symptoms to tissue-invasive, resulting in both direct and indirect sequelae. Before the advent of effective antiviral agents, the primary treatment was reduction in immunosuppression (IS). While antiviral agents provide effective prophylaxis, there are several important caveats associated with their use, including drug toxicity and resistance. The traditional view attributes CMV reactivation and the ensuing clinical disease primarily to IS, either intrinsic to disease-related immune compromise or from the extrinsic administration of IS agents. However, previous data from both animal models and human subjects showed that inflammatory signals could induce upregulation of latent viral gene expression. New data demonstrate that ischemia/reperfusion is necessary and sufficient to induce CMV reactivation following murine transplantation of a latently infected graft. In this article, we review a growing body of evidence that suggests that reactivation of both human CMV and murine CMV is first triggered by molecular events that activate CMV gene expression and lytic infection and viral dissemination are then facilitated by IS. The initial activation of viral gene expression may be mediated by oxidative stress, DNA damage, or inflammatory cytokines, and these factors may act synergistically. New therapeutic approaches are needed to capture this complex array of targets.
    MeSH term(s) Animals ; Antibodies, Viral/immunology ; Cytomegalovirus/immunology ; Cytomegalovirus Infections/drug therapy ; Cytomegalovirus Infections/immunology ; Cytomegalovirus Infections/virology ; Graft Rejection/immunology ; Graft Rejection/prevention & control ; Humans ; Immunosuppressive Agents/therapeutic use ; Kidney Transplantation ; Virus Activation/immunology ; Virus Latency/immunology
    Chemical Substances Antibodies, Viral ; Immunosuppressive Agents
    Language English
    Publishing date 2020-04-14
    Publishing country United States
    Document type Journal Article ; Review
    ZDB-ID 208424-7
    ISSN 1534-6080 ; 0041-1337
    ISSN (online) 1534-6080
    ISSN 0041-1337
    DOI 10.1097/TP.0000000000003138
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Tumor Necrosis Factor Alpha Induces Reactivation of Human Cytomegalovirus Independently of Myeloid Cell Differentiation following Posttranscriptional Establishment of Latency.

    Forte, Eleonora / Swaminathan, Suchitra / Schroeder, Mark W / Kim, Jeong Yeon / Terhune, Scott S / Hummel, Mary

    mBio

    2018  Volume 9, Issue 5

    Abstract: We used the Kasumi-3 model to study human cytomegalovirus (HCMV) latency and reactivation in myeloid progenitor cells. Kasumi-3 cells were infected with HCMV strain TB40/ ... ...

    Abstract We used the Kasumi-3 model to study human cytomegalovirus (HCMV) latency and reactivation in myeloid progenitor cells. Kasumi-3 cells were infected with HCMV strain TB40/E
    MeSH term(s) Antigens, CD34/metabolism ; Ataxia Telangiectasia Mutated Proteins/metabolism ; Cell Differentiation ; Cell Line, Tumor ; Cytomegalovirus/drug effects ; Cytomegalovirus/genetics ; Cytomegalovirus/physiology ; Flow Cytometry ; Gene Expression ; Green Fluorescent Proteins/metabolism ; Humans ; Myeloid Cells/virology ; NF-kappa B/metabolism ; RNA Processing, Post-Transcriptional ; Tripartite Motif-Containing Protein 28/metabolism ; Tumor Necrosis Factor-alpha/pharmacology ; Virus Activation/drug effects ; Virus Latency
    Chemical Substances Antigens, CD34 ; NF-kappa B ; Tumor Necrosis Factor-alpha ; Green Fluorescent Proteins (147336-22-9) ; TRIM28 protein, human (EC 2.3.2.27) ; Tripartite Motif-Containing Protein 28 (EC 2.3.2.27) ; ATM protein, human (EC 2.7.11.1) ; Ataxia Telangiectasia Mutated Proteins (EC 2.7.11.1)
    Language English
    Publishing date 2018-09-11
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 2557172-2
    ISSN 2150-7511 ; 2161-2129
    ISSN (online) 2150-7511
    ISSN 2161-2129
    DOI 10.1128/mBio.01560-18
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Epigenetic reprogramming of host and viral genes by Human Cytomegalovirus infection in Kasumi-3 myeloid progenitor cells at early times post-infection.

    Forte, Eleonora / Ayaloglu Butun, Fatma / Marinaccio, Christian / Schipma, Matthew J / Piunti, Andrea / Schroeder, Mark W / Kandpal, Manoj / Shilatifard, Ali / Abecassis, Michael / Hummel, Mary

    Journal of virology

    2021  Volume 95, Issue 11

    Abstract: HCMV establishes latency in myeloid cells. Using the Kasumi-3 latency model, we previously showed that lytic gene expression is activated prior to establishment of latency in these cells. The early events in infection may have a critical role in shaping ... ...

    Abstract HCMV establishes latency in myeloid cells. Using the Kasumi-3 latency model, we previously showed that lytic gene expression is activated prior to establishment of latency in these cells. The early events in infection may have a critical role in shaping establishment of latency. Here, we have used an integrative multi-omics approach to investigate dynamic changes in host and HCMV gene expression and epigenomes at early times post infection. Our results show dynamic changes in viral gene expression and viral chromatin. Analyses of Pol II, H3K27Ac and H3K27me3 occupancy of the viral genome showed that 1) Pol II occupancy was highest at the MIEP at 4 hours post infection. However, it was observed throughout the genome; 2) At 24 hours, H3K27Ac was localized to the major immediate early promoter/enhancer and to a possible second enhancer in the origin of replication Ori
    Language English
    Publishing date 2021-03-17
    Publishing country United States
    Document type Journal Article
    ZDB-ID 80174-4
    ISSN 1098-5514 ; 0022-538X
    ISSN (online) 1098-5514
    ISSN 0022-538X
    DOI 10.1128/JVI.00183-21
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article: MCMV Dissemination from Latently-Infected Allografts Following Transplantation into Pre-Tolerized Recipients.

    Shah, Sahil / DeBerge, Matthew / Iovane, Andre / Yan, Shixian / Qiu, Longhui / Wang, Jiao-Jing / Kanwar, Yashpal S / Hummel, Mary / Zhang, Zheng J / Abecassis, Michael M / Luo, Xunrong / Thorp, Edward B

    Pathogens (Basel, Switzerland)

    2020  Volume 9, Issue 8

    Abstract: Transplantation tolerance is achieved when recipients are unresponsive to donor alloantigen yet mobilize against third-party antigens, including virus. After transplantation, cytomegalovirus (CMV) reactivation in latently-infected transplants reduces ... ...

    Abstract Transplantation tolerance is achieved when recipients are unresponsive to donor alloantigen yet mobilize against third-party antigens, including virus. After transplantation, cytomegalovirus (CMV) reactivation in latently-infected transplants reduces allograft viability. To determine if pre-tolerized recipients are resistant to viral dissemination in this setting, we transfused chemically-fixed donor splenocytes (1-ethyl-3- (3'-dimethyl-aminopropyl)-carbo-diimide (ECDI)-treated splenocytes (ECDIsp)) to induce donor antigen tolerance without immunosuppression. In parallel, we implanted donor islet cells to validate operational tolerance. These pre-tolerized recipients were implanted with murine CMV (MCMV) latently-infected donor kidneys (a validated model of CMV latency) to monitor graft inflammation and viral dissemination. Our results indicate that tolerance to donor islets was sustained in recipients after implantation of donor kidneys. In addition, kidney allografts implanted after ECDIsp and islet implantation exhibited low levels of fibrosis and tubulitis. In contrast, kidney cellular and innate immune infiltrates trended higher in the CMV group and exhibited increased markers of CD8
    Keywords covid19
    Language English
    Publishing date 2020-07-26
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2695572-6
    ISSN 2076-0817
    ISSN 2076-0817
    DOI 10.3390/pathogens9080607
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article: MCMV Dissemination from Latently-Infected Allografts Following Transplantation into Pre-Tolerized Recipients

    Shah, Sahil / DeBerge, Matthew / Iovane, Andre / Yan, Shixian / Qiu, Longhui / Wang, Jiao-Jing / Kanwar, Yashpal S / Hummel, Mary / Zhang, Zheng J / Abecassis, Michael M / Luo, Xunrong / Thorp, Edward B

    Pathogens. 2020 July 26, v. 9, no. 8

    2020  

    Abstract: Transplantation tolerance is achieved when recipients are unresponsive to donor alloantigen yet mobilize against third-party antigens, including virus. After transplantation, cytomegalovirus (CMV) reactivation in latently-infected transplants reduces ... ...

    Abstract Transplantation tolerance is achieved when recipients are unresponsive to donor alloantigen yet mobilize against third-party antigens, including virus. After transplantation, cytomegalovirus (CMV) reactivation in latently-infected transplants reduces allograft viability. To determine if pre-tolerized recipients are resistant to viral dissemination in this setting, we transfused chemically-fixed donor splenocytes (1-ethyl-3- (3′-dimethyl-aminopropyl)-carbo-diimide (ECDI)-treated splenocytes (ECDIsp)) to induce donor antigen tolerance without immunosuppression. In parallel, we implanted donor islet cells to validate operational tolerance. These pre-tolerized recipients were implanted with murine CMV (MCMV) latently-infected donor kidneys (a validated model of CMV latency) to monitor graft inflammation and viral dissemination. Our results indicate that tolerance to donor islets was sustained in recipients after implantation of donor kidneys. In addition, kidney allografts implanted after ECDIsp and islet implantation exhibited low levels of fibrosis and tubulitis. In contrast, kidney cellular and innate immune infiltrates trended higher in the CMV group and exhibited increased markers of CD8⁺ T cell activation. Tolerance induction was unable to prevent increases in MCMV-specific CD8⁺ T cells or dissemination of viral IE-1 DNA. Our data suggest that latently-infected allografts are inherently more susceptible to inflammation that is associated with viral dissemination in pre-tolerized recipients. Thus, CMV latently-infected allografts require enhanced strategies to protect allograft integrity and viral spread.
    Keywords Cytomegalovirus ; DNA ; T-lymphocytes ; allografting ; antigens ; fibrosis ; immunosuppression ; inflammation ; islets of Langerhans ; kidneys ; mice ; model validation ; pathogens ; splenocytes ; viability ; viruses
    Language English
    Dates of publication 2020-0726
    Publishing place Multidisciplinary Digital Publishing Institute
    Document type Article
    Note NAL-light
    ZDB-ID 2695572-6
    ISSN 2076-0817
    ISSN 2076-0817
    DOI 10.3390/pathogens9080607
    Database NAL-Catalogue (AGRICOLA)

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  9. Article ; Online: A clinically relevant murine model unmasks a "two-hit" mechanism for reactivation and dissemination of cytomegalovirus after kidney transplant.

    Zhang, Zheng / Qiu, Longhui / Yan, Shixian / Wang, Jiao-Jing / Thomas, Paul M / Kandpal, Manoj / Zhao, Lihui / Iovane, Andre / Liu, Xue-Feng / Thorp, Edward B / Chen, Qing / Hummel, Mary / Kanwar, Yashpal S / Abecassis, Michael M

    American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons

    2019  Volume 19, Issue 9, Page(s) 2421–2433

    Abstract: Reactivation of latent cytomegalovirus remains an important complication after transplant. Although immunosuppression (IS) has been implicated as a primary cause, we have previously shown that the implantation response of a kidney allograft can lead to ... ...

    Abstract Reactivation of latent cytomegalovirus remains an important complication after transplant. Although immunosuppression (IS) has been implicated as a primary cause, we have previously shown that the implantation response of a kidney allograft can lead to early transcriptional activation of latent murine cytomegalovirus (MCMV) genes in an immune-competent host and to MCMV reactivation and dissemination to other organs in a genetically immune-deficient recipient. We now describe a model that allows us to separately analyze the impact of the implantation effect vs that of a clinically relevant IS regimen. Treatment with IS of latently infected mice alone does not induce viral reactivation, but transplant of latently infected allogeneic kidneys combined with IS facilitates MCMV reactivation in the graft and dissemination to other organs. The IS regimen effectively dampens allo-immune inflammatory pathways and depletes recipient anti-MCMV but does not affect ischemia-reperfusion injury pathways. MCMV reactivation similar to that seen in allogeneic transplants combined with also occurs after syngeneic transplants. Thus, our data strongly suggest that while ischemia-reperfusion injury of the implanted graft is sufficient and necessary to initiate transcriptional reactivation of latent MCMV ("first hit"), IS is permissive to the first hit and facilitates dissemination to other organs ("second hit").
    MeSH term(s) Animals ; Cytomegalovirus Infections/complications ; Disease Models, Animal ; Gene Deletion ; Histones/metabolism ; Immunosuppression Therapy ; Kidney/pathology ; Kidney Transplantation/adverse effects ; Mice ; Mice, Inbred BALB C ; Muromegalovirus/physiology ; Phenotype ; Postoperative Complications/virology ; Proteomics ; Renal Insufficiency/complications ; Renal Insufficiency/surgery ; Reperfusion Injury ; Transplantation, Homologous ; Virus Activation
    Chemical Substances Histones
    Language English
    Publishing date 2019-05-14
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 2060594-8
    ISSN 1600-6143 ; 1600-6135
    ISSN (online) 1600-6143
    ISSN 1600-6135
    DOI 10.1111/ajt.15376
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: Epigenetic control of cytomegalovirus latency and reactivation.

    Liu, Xue-feng / Wang, Xueqiong / Yan, Shixian / Zhang, Zheng / Abecassis, Michael / Hummel, Mary

    Viruses

    2013  Volume 5, Issue 5, Page(s) 1325–1345

    Abstract: Cytomegalovirus (CMV) gene expression is repressed in latency due to heterochromatinization of viral genomes. In murine CMV (MCMV) latently infected mice, viral genomes are bound to histones with heterochromatic modifications, to enzymes that mediate ... ...

    Abstract Cytomegalovirus (CMV) gene expression is repressed in latency due to heterochromatinization of viral genomes. In murine CMV (MCMV) latently infected mice, viral genomes are bound to histones with heterochromatic modifications, to enzymes that mediate these modifications, and to adaptor proteins that may recruit co-repressor complexes. Kinetic analyses of repressor binding show that these repressors are recruited at the earliest time of infection, suggesting that latency may be the default state. Kidney transplantation leads to epigenetic reprogramming of latent viral chromatin and reactivation of immediate early gene expression. Inflammatory signaling pathways, which activate transcription factors that regulate the major immediate early promoter (MIEP), likely mediate the switch in viral chromatin.
    MeSH term(s) Cytomegalovirus/genetics ; Cytomegalovirus/physiology ; Epigenesis, Genetic ; Gene Expression Regulation, Viral ; Host-Pathogen Interactions ; Humans ; Virus Activation ; Virus Latency
    Language English
    Publishing date 2013-05-23
    Publishing country Switzerland
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Review
    ZDB-ID 2516098-9
    ISSN 1999-4915 ; 1999-4915
    ISSN (online) 1999-4915
    ISSN 1999-4915
    DOI 10.3390/v5051325
    Database MEDical Literature Analysis and Retrieval System OnLINE

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