1
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Crawford LB. Hematopoietic stem cells and betaherpesvirus latency. Front Cell Infect Microbiol 2023; 13:1189805. [PMID: 37346032 PMCID: PMC10279960 DOI: 10.3389/fcimb.2023.1189805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 05/11/2023] [Indexed: 06/23/2023] Open
Abstract
The human betaherpesviruses including human cytomegalovirus (HCMV), human herpesvirus (HHV)-6a and HHV-6b, and HHV-7 infect and establish latency in CD34+ hematopoietic stem and progenitor cells (HPCs). The diverse repertoire of HPCs in humans and the complex interactions between these viruses and host HPCs regulate the viral lifecycle, including latency. Precise manipulation of host and viral factors contribute to preferential maintenance of the viral genome, increased host cell survival, and specific manipulation of the cellular environment including suppression of neighboring cells and immune control. The dynamic control of these processes by the virus regulate inter- and intra-host signals critical to the establishment of chronic infection. Regulation occurs through direct viral protein interactions and cellular signaling, miRNA regulation, and viral mimics of cellular receptors and ligands, all leading to control of cell proliferation, survival, and differentiation. Hematopoietic stem cells have unique biological properties and the tandem control of virus and host make this a unique environment for chronic herpesvirus infection in the bone marrow. This review highlights the elegant complexities of the betaherpesvirus latency and HPC virus-host interactions.
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Affiliation(s)
- Lindsey B Crawford
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, United States
- Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE, United States
- Nebraska Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, NE, United States
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2
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Effect of Cytomegalovirus on the Immune System: Implications for Aging and Mental Health. Curr Top Behav Neurosci 2022; 61:181-214. [PMID: 35871707 DOI: 10.1007/7854_2022_376] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Human cytomegalovirus (HCMV) is a major modulator of the immune system leading to long-term changes in T-lymphocytes, macrophages, and natural killer (NK) cells among others. Perhaps because of this immunomodulatory capacity, HCMV infection has been linked with a host of deleterious effects including accelerated immune aging (premature mortality, increased expression of immunosenescence-linked markers, telomere shortening, speeding-up of epigenetic "clocks"), decreased vaccine immunogenicity, and greater vulnerability to infectious diseases (e.g., tuberculosis) or infectious disease-associated pathology (e.g., HIV). Perhaps not surprisingly given the long co-evolution between HCMV and humans, the virus has also been associated with beneficial effects, such as increased vaccine responsiveness, heterologous protection against infections, and protection against relapse in the context of leukemia. Here, we provide an overview of this literature. Ultimately, we focus on one other deleterious effect of HCMV, namely the emerging literature suggesting that HCMV plays a pathophysiological role in psychiatric illness, particularly depression and schizophrenia. We discuss this literature through the lens of psychological stress and inflammation, two well-established risk factors for psychiatric illness that are also known to predispose to reactivation of HCMV.
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Wang H, Qi J, Li X, Chu T, Qiu H, Fu C, Tang X, Ruan C, Wu D, Han Y. Prognostic Value of Thrombocytopenia in Myelodysplastic Syndromes After Hematopoietic Stem Cell Transplantation. Front Oncol 2022; 12:940320. [PMID: 35898899 PMCID: PMC9309887 DOI: 10.3389/fonc.2022.940320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 06/21/2022] [Indexed: 11/13/2022] Open
Abstract
Prolonged isolated thrombocytopenia (PT) is a common complication affecting the outcome of stem cell transplantation. In this study, we undertook a real-world study of 303 myelodysplastic syndrome (MDS) patients who received allogeneic hematopoietic stem cell transplantation (HSCT) between December 2007 and June 2018. 28.4% of MDS patients suffered from PT after HSCT. Survival analysis indicated that PT was associated with worse overall survival (OS) in MDS patients. The 2-year and 5-year OS in MDS patients with PT after HSCT were 49% and 47%, significantly worse than that of 68% and 60% in patients without PT (P=0.005). For RFS, patients with PT did not have an increased risk of disease relapse (P=0.964). After multivariate adjustment, PT was proved to be the independent risk factor associated with the worse OS (HR 1.49, 95% CI 1.00-2.21, P =0.048). We further analyzed risk factors associated with the occurrence of PT in MDS patients. Multiple logistic regression identified grade II-IV aGVHD, extensive chronic GVHD, hemorrhagic cystitis, and CMV activation as significant risk factors for developing PT. Among these variables, the Odds Ratio (OR) of grade II-IV aGVHD was the highest (P =0.001, OR: 2.65, 95% CI: 1.51-4.64). These data indicated the prognostic value of PT in MDS after HSCT. The identification of risk factors for PT may help improve patient management and lead to the design of effective treatment strategies.
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Affiliation(s)
- Hong Wang
- National Clinical Research Center for Hematologic Diseases, Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, China
- Institute of Blood and Marrow Transplantation, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, China
- Key Laboratory of Thrombosis and Hemostasis of Ministry of Health, Suzhou, China
| | - Jiaqian Qi
- National Clinical Research Center for Hematologic Diseases, Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, China
- Institute of Blood and Marrow Transplantation, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, China
- Key Laboratory of Thrombosis and Hemostasis of Ministry of Health, Suzhou, China
| | - Xueqian Li
- National Clinical Research Center for Hematologic Diseases, Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, China
- Institute of Blood and Marrow Transplantation, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, China
- Key Laboratory of Thrombosis and Hemostasis of Ministry of Health, Suzhou, China
| | - Tiantian Chu
- National Clinical Research Center for Hematologic Diseases, Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, China
- Institute of Blood and Marrow Transplantation, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, China
- Key Laboratory of Thrombosis and Hemostasis of Ministry of Health, Suzhou, China
| | - Huiying Qiu
- National Clinical Research Center for Hematologic Diseases, Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, China
- Institute of Blood and Marrow Transplantation, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, China
- Key Laboratory of Thrombosis and Hemostasis of Ministry of Health, Suzhou, China
| | - Chengcheng Fu
- National Clinical Research Center for Hematologic Diseases, Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, China
- Institute of Blood and Marrow Transplantation, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, China
- Key Laboratory of Thrombosis and Hemostasis of Ministry of Health, Suzhou, China
| | - Xiaowen Tang
- National Clinical Research Center for Hematologic Diseases, Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, China
- Institute of Blood and Marrow Transplantation, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, China
- Key Laboratory of Thrombosis and Hemostasis of Ministry of Health, Suzhou, China
| | - Changgeng Ruan
- National Clinical Research Center for Hematologic Diseases, Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, China
- Institute of Blood and Marrow Transplantation, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, China
- Key Laboratory of Thrombosis and Hemostasis of Ministry of Health, Suzhou, China
| | - Depei Wu
- National Clinical Research Center for Hematologic Diseases, Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, China
- Institute of Blood and Marrow Transplantation, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, China
- Key Laboratory of Thrombosis and Hemostasis of Ministry of Health, Suzhou, China
- State Key Laboratory of Radiation Medicine and Protection, Soochow University, Suzhou, China
- *Correspondence: Yue Han, ; Depei Wu,
| | - Yue Han
- National Clinical Research Center for Hematologic Diseases, Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, China
- Institute of Blood and Marrow Transplantation, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, China
- Key Laboratory of Thrombosis and Hemostasis of Ministry of Health, Suzhou, China
- State Key Laboratory of Radiation Medicine and Protection, Soochow University, Suzhou, China
- *Correspondence: Yue Han, ; Depei Wu,
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Haidar Ahmad S, Pasquereau S, El Baba R, Nehme Z, Lewandowski C, Herbein G. Distinct Oncogenic Transcriptomes in Human Mammary Epithelial Cells Infected With Cytomegalovirus. Front Immunol 2022; 12:772160. [PMID: 35003089 PMCID: PMC8727587 DOI: 10.3389/fimmu.2021.772160] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 11/24/2021] [Indexed: 12/13/2022] Open
Abstract
Human cytomegalovirus is being recognized as a potential oncovirus beside its oncomodulation role. We previously isolated two clinical isolates, HCMV-DB (KT959235) and HCMV-BL (MW980585), which in primary human mammary epithelial cells promoted oncogenic molecular pathways, established anchorage-independent growth in vitro, and produced tumorigenicity in mice models, therefore named high-risk oncogenic strains. In contrast, other clinical HCMV strains such as HCMV-FS, KM, and SC did not trigger such traits, therefore named low-risk oncogenic strains. In this study, we compared high-risk oncogenic HCMV-DB and BL strains (high-risk) with low-risk oncogenic strains HCMV-FS, KM, and SC (low-risk) additionally to the prototypic HCMV-TB40/E, knowing that all strains infect HMECs in vitro. Numerous pro-oncogenic features including enhanced expression of oncogenes, cell survival, proliferation, and epithelial-mesenchymal transition genes were observed with HCMV-BL. In vitro, mammosphere formation was observed only in high-risk strains. HCMV-TB40/E showed an intermediate transcriptome landscape with limited mammosphere formation. Since we observed that Ki67 gene expression allows us to discriminate between high and low-risk HCMV strains in vitro, we further tested its expression in vivo. Among HCMV-positive breast cancer biopsies, we only detected high expression of the Ki67 gene in basal tumors which may correspond to the presence of high-risk HCMV strains within tumors. Altogether, the transcriptome of HMECs infected with HCMV clinical isolates displays an “oncogenic gradient” where high-risk strains specifically induce a prooncogenic environment which might participate in breast cancer development.
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Affiliation(s)
- Sandy Haidar Ahmad
- Pathogens & Inflammation/EPILAB Laboratory, EA4266, Université de Franche-Comté, Université Bourgogne Franche-Comté (UBFC), Besançon, France
| | - Sébastien Pasquereau
- Pathogens & Inflammation/EPILAB Laboratory, EA4266, Université de Franche-Comté, Université Bourgogne Franche-Comté (UBFC), Besançon, France
| | - Ranim El Baba
- Pathogens & Inflammation/EPILAB Laboratory, EA4266, Université de Franche-Comté, Université Bourgogne Franche-Comté (UBFC), Besançon, France
| | - Zeina Nehme
- Pathogens & Inflammation/EPILAB Laboratory, EA4266, Université de Franche-Comté, Université Bourgogne Franche-Comté (UBFC), Besançon, France
| | - Clara Lewandowski
- Pathogens & Inflammation/EPILAB Laboratory, EA4266, Université de Franche-Comté, Université Bourgogne Franche-Comté (UBFC), Besançon, France
| | - Georges Herbein
- Pathogens & Inflammation/EPILAB Laboratory, EA4266, Université de Franche-Comté, Université Bourgogne Franche-Comté (UBFC), Besançon, France.,Department of Virology, Centre Hospitalier Universitaire (CHU) Besançon, Besançon, France
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Liu Z, Xuan B, Tang S, Qian Z. Histone Deacetylase Inhibitor SAHA Induces Expression of Fatty Acid-Binding Protein 4 and Inhibits Replication of Human Cytomegalovirus. Virol Sin 2021; 36:1352-1362. [PMID: 34156645 DOI: 10.1007/s12250-021-00382-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 03/11/2021] [Indexed: 10/21/2022] Open
Abstract
Suberoylanilide hydroxamic acid (SAHA) is a histone deacetylase inhibitor that shows marked efficacy against many types of cancers and is approved to treat severe metastatic cutaneous T-cell lymphomas. In addition to its anticancer activity, SAHA has significant effects on the growth of many viruses. The effect of SAHA on replication of human cytomegalovirus (HCMV) has not, however, been investigated. Here, we showed that the replication of HCMV was significantly suppressed by treatment with SAHA at concentrations that did not show appreciable cytotoxicity. SAHA reduced transcription and protein levels of HCMV immediate early genes, showing that SAHA acts at an early stage in the viral life-cycle. RNA-sequencing data mining showed that numerous pathways and molecules were affected by SAHA. Interferon-mediated immunity was one of the most relevant pathways in the RNA-sequencing data, and we confirmed that SAHA inhibits HCMV-induced IFN-mediated immune responses using quantitative Real-time PCR (qRT-PCR). Fatty acid-binding protein 4 (FABP4), which plays a role in lipid metabolism, was identified by RNA-sequencing. We found that FABP4 expression was reduced by HCMV infection but increased by treatment with SAHA. We then showed that knockdown of FABP4 partially rescued the effect of SAHA on HCMV replication. Our data suggest that FABP4 contributes to the inhibitory effect of SAHA on HCMV replication.
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Affiliation(s)
- Zhongshun Liu
- CAS Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, University of the Chinese Academy of Sciences, Shanghai, 200031, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Baoqin Xuan
- CAS Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, University of the Chinese Academy of Sciences, Shanghai, 200031, China
| | - Shubing Tang
- CAS Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, University of the Chinese Academy of Sciences, Shanghai, 200031, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhikang Qian
- CAS Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, University of the Chinese Academy of Sciences, Shanghai, 200031, China.
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6
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Diggins NL, Crawford LB, Hancock MH, Mitchell J, Nelson JA. Human Cytomegalovirus miR-US25-1 Targets the GTPase RhoA To Inhibit CD34 + Hematopoietic Progenitor Cell Proliferation To Maintain the Latent Viral Genome. mBio 2021; 12:e00621-21. [PMID: 33824207 PMCID: PMC8092260 DOI: 10.1128/mbio.00621-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 03/09/2021] [Indexed: 12/25/2022] Open
Abstract
Human cytomegalovirus (HCMV) microRNAs play essential roles in latency and reactivation in CD34+ hematopoietic progenitor cells (HPCs) via regulation of viral and cellular gene expression. In the present study, we show that HCMV miR-US25-1 targets RhoA, a small GTPase required for CD34+ HPC self-renewal, proliferation, and hematopoiesis. Expression of miR-US25-1 impairs signaling through the nonmuscle myosin II light chain, which leads to a block in cytokinesis and an inhibition of proliferation. Moreover, infection with an HCMV mutant lacking miR-US25-1 resulted in increased proliferation of CD34+ HPCs and a decrease in the proportion of genome-containing cells at the end of latency culture. These observations provide a mechanism by which HCMV limits proliferation to maintain latent viral genomes in CD34+ HPCs.IMPORTANCE Each herpesvirus family establishes latency in a unique cell type. Since herpesvirus genomes are maintained as episomes, the virus needs to devise mechanisms to retain the latent genome during cell division. Alphaherpesviruses overcome this obstacle by infecting nondividing neurons, while gammaherpesviruses tether their genome to the host chromosome in dividing B cells. The betaherpesvirus human cytomegalovirus (HCMV) establishes latency in CD34+ hematopoietic progenitor cells (HPCs), but the mechanism used to maintain the viral genome is unknown. In this report, we demonstrate that HCMV miR-US25-1 downregulates expression of RhoA, a key cell cycle regulator, which results in inhibition of CD34+ HPC proliferation by blocking mitosis. Mutation of miR-US25-1 during viral infection results in enhanced cellular proliferation and a decreased frequency of genome-containing CD34+ HPCs. These results reveal a novel mechanism through which HCMV is able to regulate cell division to prevent viral genome loss during proliferation.
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Affiliation(s)
- Nicole L Diggins
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Lindsey B Crawford
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Meaghan H Hancock
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Jennifer Mitchell
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Jay A Nelson
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
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7
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New Insights Into the Molecular Mechanisms and Immune Control of Cytomegalovirus Reactivation. Transplantation 2020; 104:e118-e124. [PMID: 31996662 PMCID: PMC7790173 DOI: 10.1097/tp.0000000000003138] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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.
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Baasch S, Ruzsics Z, Henneke P. Cytomegaloviruses and Macrophages-Friends and Foes From Early on? Front Immunol 2020; 11:793. [PMID: 32477336 PMCID: PMC7235172 DOI: 10.3389/fimmu.2020.00793] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 04/07/2020] [Indexed: 01/01/2023] Open
Abstract
Starting at birth, newborn infants are exposed to numerous microorganisms. Adaptation of the innate immune system to them is a delicate process, with potentially advantageous and harmful implications for health development. Cytomegaloviruses (CMVs) are highly adapted to their specific mammalian hosts, with which they share millions of years of co-evolution. Throughout the history of mankind, human CMV has infected most infants in the first months of life without overt implications for health. Thus, CMV infections are intertwined with normal immune development. Nonetheless, CMV has retained substantial pathogenicity following infection in utero or in situations of immunosuppression, leading to pathology in virtually any organ and particularly the central nervous system (CNS). CMVs enter the host through mucosal interfaces of the gastrointestinal and respiratory tract, where macrophages (MACs) are the most abundant immune cell type. Tissue MACs and their potential progenitors, monocytes, are established target cells of CMVs. Recently, several discoveries have revolutionized our understanding on the pre- and postnatal development and site-specific adaptation of tissue MACs. In this review, we explore experimental evidences and concepts on how CMV infections may impact on MAC development and activation as part of host-virus co-adaptation.
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Affiliation(s)
- Sebastian Baasch
- Institute for Immunodeficiency, Center for Chronic Immunodeficiency (CCI), Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center for Pediatrics and Adolescent Medicine, University of Freiburg, Freiburg, Germany
| | - Zsolt Ruzsics
- Institute of Virology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Philipp Henneke
- Institute for Immunodeficiency, Center for Chronic Immunodeficiency (CCI), Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center for Pediatrics and Adolescent Medicine, University of Freiburg, Freiburg, Germany
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9
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Forte E, Zhang Z, Thorp EB, Hummel M. Cytomegalovirus Latency and Reactivation: An Intricate Interplay With the Host Immune Response. Front Cell Infect Microbiol 2020; 10:130. [PMID: 32296651 PMCID: PMC7136410 DOI: 10.3389/fcimb.2020.00130] [Citation(s) in RCA: 113] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 03/10/2020] [Indexed: 12/16/2022] Open
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.
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Affiliation(s)
- Eleonora Forte
- Department of Surgery, Comprehensive Transplant Center, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Zheng Zhang
- Department of Surgery, Comprehensive Transplant Center, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Edward B. Thorp
- Department of Pathology and Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Mary Hummel
- Department of Surgery, Comprehensive Transplant Center, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
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Lee JH, Pasquarella JR, Kalejta RF. Cell Line Models for Human Cytomegalovirus Latency Faithfully Mimic Viral Entry by Macropinocytosis and Endocytosis. J Virol 2019; 93:e01021-19. [PMID: 31391271 PMCID: PMC6803280 DOI: 10.1128/jvi.01021-19] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 08/05/2019] [Indexed: 02/06/2023] Open
Abstract
Human cytomegalovirus (HCMV) enters primary CD34+ hematopoietic progenitor cells by macropinocytosis, where it establishes latency in part because its tegument-transactivating protein, pp71, remains associated with endosomes and is therefore unable to initiate productive, lytic replication. Here we show that multiple HCMV strains also enter cell line models used to study latency by macropinocytosis and endocytosis. In all latency models tested, tegument-delivered pp71 was found to be colocalized with endosomal markers and was not associated with the seven other cytoplasmic localization markers tested. Like the capsid-associated pp150 tegument protein, we initially detected capsid proteins in association with endosomes but later detected them in the nucleus. Inhibitors of macropinocytosis and endocytosis reduced latent viral gene expression and precluded reactivation. Importantly, we utilized electron microscopy to observe entry by macropinocytosis and endocytosis, providing additional visual corroboration of the findings of our functional studies. Our demonstration that HCMV enters cell line models for latency in a manner indistinguishable from that of its entry into primary cells illustrates the utility of these cell lines for probing the mechanisms, host genetics, and small-molecule-mediated inhibition of HCMV entry into the cell types where it establishes latency.IMPORTANCE Primary cells cultured in vitro currently provide the highest available relevance for examining molecular and genetic requirements for the establishment, maintenance, and reactivation of HCMV latency. However, their expense, heterogeneity, and intransigence to both long-term culture and molecular or genetic modification create rigor and reproducibility challenges for HCMV latency studies. There are several cell line models for latency not obstructed by deficiencies inherent in primary cells. However, many researchers view cell line studies of latency to be physiologically irrelevant because of the perception that these models display numerous and significant differences from primary cells. Here, we show that the very first step in a latent HCMV infection, entry of the virus into cells, occurs in cell line models in a manner indistinguishable from that in which it occurs in primary CD34+ hematopoietic progenitor cells. Our data argue that experimental HCMV latency is much more similar than it is different in cell lines and primary cells.
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Affiliation(s)
- Jeong-Hee Lee
- Institute for Molecular Virology and McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Joseph R Pasquarella
- Institute for Molecular Virology and McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Robert F Kalejta
- Institute for Molecular Virology and McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, Wisconsin, USA
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11
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Schwartz M, Stern-Ginossar N. The Transcriptome of Latent Human Cytomegalovirus. J Virol 2019; 93:e00047-19. [PMID: 30867313 PMCID: PMC6532091 DOI: 10.1128/jvi.00047-19] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 03/09/2019] [Indexed: 12/29/2022] Open
Abstract
The latent human cytomegalovirus (HCMV) transcriptome has been extremely difficult to define due to the scarcity of naturally latent cells and the complexity of available models. The genomic era offers many approaches to transcriptome profiling that hold great potential for elucidating this challenging issue. The results from two recent studies applying different transcriptomic methodologies and analyses of both experimental and natural samples challenge the dogma of a restricted latency-associated transcription program. Instead, they portray the hallmark of HCMV latent infection as low-level expression of a broad spectrum of canonical viral lytic genes.
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Affiliation(s)
- Michal Schwartz
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Noam Stern-Ginossar
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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12
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Foglierini M, Marcandalli J, Perez L. HCMV Envelope Glycoprotein Diversity Demystified. Front Microbiol 2019; 10:1005. [PMID: 31156572 PMCID: PMC6529531 DOI: 10.3389/fmicb.2019.01005] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 04/18/2019] [Indexed: 12/27/2022] Open
Abstract
Human cytomegalovirus (HCMV) is the leading viral cause of congenital birth defects and is responsible for morbidity and mortality in immunosuppressed individuals. Considerable efforts have been deployed over the last decade to develop a vaccine capable of preventing HCMV infection. However, in recent clinical trials, vaccines showed at best modest efficacy in preventing infection. These findings might be explained by the high level of sequence polymorphism at the genomic level. To investigate if genomic variation also leads to antigenic variation, we performed a bioinformatic sequence analysis and evaluated the percentage of conservation at the amino acid level of all the proteins present in the virion envelope. Using more than two hundred sequences per envelope glycoprotein and analyzing their degree of conservation, we observe that antigenic variation is in large part limited to three proteins. In addition, we demonstrate that the two leading vaccine candidates, the pentamer and gB complexes, are well conserved at the amino acid level. These results suggest that despite genomic polymorphism, antigenic variability is not involved in the modest efficacy observed in the recent clinical trials for a HCMV vaccine. We therefore propose that next-generation vaccines should focus on stabilizing and refining the gB domains needed to induce a protective humoral response.
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Affiliation(s)
- Mathilde Foglierini
- Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera Italiana, Bellinzona, Switzerland.,Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Jessica Marcandalli
- Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera Italiana, Bellinzona, Switzerland
| | - Laurent Perez
- Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera Italiana, Bellinzona, Switzerland
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Selective 4-Thiouracil Labeling of RNA Transcripts within Latently Infected Cells after Infection with Human Cytomegalovirus Expressing Functional Uracil Phosphoribosyltransferase. J Virol 2018; 92:JVI.00880-18. [PMID: 30089702 DOI: 10.1128/jvi.00880-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 08/03/2018] [Indexed: 12/25/2022] Open
Abstract
Infections with human cytomegalovirus (HCMV) are highly prevalent in the general population as the virus has evolved the capacity to undergo distinct replication strategies resulting in lytic, persistent, and latent infections. During the latent life cycle, HCMV resides in subsets of cells within the hematopoietic cell compartment, including hematopoietic progenitor cells (HPCs) and peripheral blood monocytes. Since only a small fraction of these cell types harbor viral genomes during natural latency, identification and analysis of distinct changes mediated by viral infection are difficult to assess. In order to characterize latent infections of HPCs, we used an approach that involves complementation of deficiencies within the human pyrimidine salvage pathway, thus allowing for conversion of labeled uracil into rUTP. Here, we report the development of a recombinant HCMV that complements the defective human pyrimidine salvage pathway, allowing incorporation of thiol containing UTP into all RNA species that are synthesized within an infected cell. This virus grows to wild-type kinetics and can establish a latent infection within two distinct culture models of HCMV latency. Using this recombinant HCMV, we report the specific labeling of transcripts only within infected cells. These transcripts reveal a transcriptional landscape during HCMV latency that is distinct from uninfected cells. The utility of this labeling system allows for the identification of distinct changes within host transcripts and will shed light on characterizing how HCMV establishes and maintains latency.IMPORTANCE HCMV is a significant pathogen that accounts for a substantial amount of complications within the immunosuppressed and immunocompromised. Of particular significance is the capacity of HCMV to reactivate within solid tissue and bone marrow transplant recipients. While it is known that HCMV latency resides within a fraction of HPCs and monocytes, the exact subset of cells that harbor latent viral genomes during natural infections remain uncharacterized. The capacity to identify changes within the host transcriptome during latent infections is critical for developing approaches that therapeutically or physically eliminate latent viral genome containing cells and will represent a major breakthrough for reducing complications due to HCMV reactivation posttransplant. In this report, we describe the generation and use of a recombinant HCMV that allows specific and distinct labeling of RNA species that are produced within virally infected cells. This is a critical first step in identifying how HCMV affects the host cell during latency and more importantly, allows one to characterize cells that harbor latent HCMV.
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14
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HCMV Infection and Apoptosis: How Do Monocytes Survive HCMV Infection? Viruses 2018; 10:v10100533. [PMID: 30274264 PMCID: PMC6213175 DOI: 10.3390/v10100533] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 09/10/2018] [Accepted: 09/26/2018] [Indexed: 12/11/2022] Open
Abstract
Human cytomegalovirus (HCMV) infection of peripheral blood monocytes plays a key role in the hematogenous dissemination of the virus to multiple organ systems following primary infection or reactivation of latent virus in the bone marrow. Monocytes have a short life span of 1⁻3 days in circulation; thus, HCMV must alter their survival and differentiation to utilize these cells and their differentiated counterparts-macrophages-for dissemination and long term viral persistence. Because monocytes are not initially permissive for viral gene expression and replication, HCMV must control host-derived factors early during infection to prevent apoptosis or programmed cell death prior to viral induced differentiation into naturally long-lived macrophages. This review provides a short overview of HCMV infection of monocytes and describes how HCMV has evolved to utilize host cell anti-apoptotic pathways to allow infected monocytes to bridge the 48⁻72 h viability gate so that differentiation into a long term stable mature cell can occur. Because viral gene expression is delayed in monocytes following initial infection and only occurs (begins around two to three weeks post infection in our model) following what appears to be complete differentiation into mature macrophages or dendritic cells, or both; virally-encoded anti-apoptotic gene products cannot initially control long term infected cell survival. Anti-apoptotic viral genes are discussed in the second section of this review and we argue they would play an important role in long term macrophage or dendritic cell survival following infection-induced differentiation.
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15
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Tumor Necrosis Factor Alpha Induces Reactivation of Human Cytomegalovirus Independently of Myeloid Cell Differentiation following Posttranscriptional Establishment of Latency. mBio 2018; 9:mBio.01560-18. [PMID: 30206173 PMCID: PMC6134100 DOI: 10.1128/mbio.01560-18] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
HCMV is an important human pathogen that establishes lifelong latent infection in myeloid progenitor cells and reactivates frequently to cause significant disease in immunocompromised people. Our observation that viral gene expression is first turned on and then turned off to establish latency suggests that there is a host defense, which may be myeloid cell specific, responsible for transcriptional silencing of viral gene expression. Our observation that TNF-α induces reactivation independently of differentiation provides insight into molecular mechanisms that control reactivation. 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/Ewt-GFP, flow sorted for green fluorescent protein-positive (GFP+) cells, and cultured for various times to monitor establishment of latency, as judged by repression of viral gene expression (RNA/DNA ratio) and loss of virus production. We found that, in the vast majority of cells, latency was established posttranscriptionally in the GFP+ infected cells: transcription was initially turned on and then turned off. We also found that some of the GFP− cells were infected, suggesting that latency might be established in these cells at the outset of infection. We were not able to test this hypothesis because some GFP− cells expressed lytic genes and thus it was not possible to separate them from GFP− quiescent cells. In addition, we found that the pattern of expression of lytic genes that have been associated with latency, including UL138, US28, and RNA2.7, was the same as that of other lytic genes, indicating that there was no preferential expression of these genes once latency was established. We confirmed previous studies showing that tumor necrosis factor alpha (TNF-α) induced reactivation of infectious virus, and by analyzing expression of the progenitor cell marker CD34 as well as myeloid cell differentiation markers in IE+ cells after treatment with TNF-α, we showed that TNF-α induced transcriptional reactivation of IE gene expression independently of differentiation. TNF-α-mediated reactivation in Kasumi-3 cells was correlated with activation of NF-κB, KAP-1, and ATM.
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16
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Collins-McMillen D, Buehler J, Peppenelli M, Goodrum F. Molecular Determinants and the Regulation of Human Cytomegalovirus Latency and Reactivation. Viruses 2018; 10:E444. [PMID: 30127257 PMCID: PMC6116278 DOI: 10.3390/v10080444] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 08/16/2018] [Accepted: 08/17/2018] [Indexed: 02/06/2023] Open
Abstract
Human cytomegalovirus (HCMV) is a beta herpesvirus that establishes a life-long persistence in the host, like all herpesviruses, by way of a latent infection. During latency, viral genomes are maintained in a quieted state. Virus replication can be reactivated from latency in response to changes in cellular signaling caused by stress or differentiation. The past decade has brought great insights into the molecular basis of HCMV latency. Here, we review the complex persistence of HCMV with consideration of latent reservoirs, viral determinants and their host interactions, and host signaling and the control of cellular and viral gene expression that contributes to the establishment of and reactivation from latency.
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Affiliation(s)
| | - Jason Buehler
- BIO5 Institute, University of Arizona, Tucson, AZ 85721, USA.
| | | | - Felicia Goodrum
- BIO5 Institute, University of Arizona, Tucson, AZ 85721, USA.
- Department of Immunobiology, University of Arizona, Tucson, AZ 85721, USA.
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17
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Poole EL, Kew VG, Lau JC, Murray MJ, Stamminger T, Sinclair JH, Reeves MB. A Virally Encoded DeSUMOylase Activity Is Required for Cytomegalovirus Reactivation from Latency. Cell Rep 2018; 24:594-606. [PMID: 30021158 PMCID: PMC6077246 DOI: 10.1016/j.celrep.2018.06.048] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 05/03/2018] [Accepted: 06/11/2018] [Indexed: 02/02/2023] Open
Abstract
A subset of viral genes is required for the long-term latent infection of hematopoietic cells by human cytomegalovirus (HCMV). Here, we show that a latency-associated gene product (LUNA) promotes the disruption of cellular PML bodies during latency. Mutation and inhibitor studies reveal that LUNA encodes a deSUMOylase activity responsible for this disruption. Specifically, LUNA encodes a conserved Asp-Cys-Gly motif common to all deSUMOylases. Importantly, mutation of the putative catalytic cysteine is sufficient to reverse LUNA-mediated PML dispersal and markedly reduces the efficiency of viral reactivation. The depletion of PML from cells is sufficient to rescue the reactivation of the LUNA-deficient viruses, arguing that targeting PML is an important biological role of LUNA. Finally, we demonstrate that reactivation of naturally latent HCMV is blocked by deSUMOylase inhibitors. Thus, latent HCMV primes the cellular environment for efficient reactivation via the activity of a virally encoded deSUMOylase.
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Affiliation(s)
- Emma L. Poole
- Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Cambridge CB2 2QQ, UK
| | - Verity G. Kew
- Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Cambridge CB2 2QQ, UK
| | - Jonathan C.H. Lau
- Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Cambridge CB2 2QQ, UK
| | - Matthew J. Murray
- Institute of Immunity & Transplantation, University College London, Royal Free Campus, London NW3 2PF, UK
| | | | - John H. Sinclair
- Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Cambridge CB2 2QQ, UK,Corresponding author
| | - Matthew B. Reeves
- Institute of Immunity & Transplantation, University College London, Royal Free Campus, London NW3 2PF, UK,Corresponding author
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18
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Humanes Cytomegalievirus (HCMV). Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz 2018; 61:116-128. [DOI: 10.1007/s00103-017-2661-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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19
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Kew VG, Wills MR, Reeves MB. LPS promotes a monocyte phenotype permissive for human cytomegalovirus immediate-early gene expression upon infection but not reactivation from latency. Sci Rep 2017; 7:810. [PMID: 28400599 PMCID: PMC5429787 DOI: 10.1038/s41598-017-00999-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 03/21/2017] [Indexed: 12/28/2022] Open
Abstract
Human cytomegalovirus (HCMV) infection of myeloid cells is closely linked with the differentiation status of the cell. Haematopoietic progenitors and CD14+ monocytes are usually non-permissive for lytic gene expression which can lead to the establishment of latent infections. In contrast, differentiation to macrophage or dendritic cell (DC) phenotypes promotes viral reactivation or renders them permissive for lytic infection. The observation that high doses of Lipopolysaccharide (LPS) drove rapid monocyte differentiation in mice led us to investigate the response of human monocytes to HCMV following LPS stimulation in vitro. Here we report that LPS triggers a monocyte phenotype permissiveness for lytic infection directly correlating with LPS concentration. In contrast, addition of LPS directly to latently infected monocytes was not sufficient to trigger viral reactivation which is likely linked with the failure of the monocytes to differentiate to a DC phenotype. Interestingly, we observe that this effect on lytic infection of monocytes is transient, appears to be dependent on COX-2 activation and does not result in a full productive infection. Thus LPS stimulated monocytes are partially permissive lytic gene expression but did not have long term impact on monocyte identity regarding their differentiation and susceptibility for the full lytic cycle of HCMV.
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Affiliation(s)
- V G Kew
- Department of Medicine, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
| | - M R Wills
- Department of Medicine, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK.
| | - M B Reeves
- Institute of Immunity & Transplantation, UCL Division of Infection & Immunity, Royal Free Hospital, London, NW3 2PF, UK.
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20
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Kim JH, Collins-McMillen D, Buehler JC, Goodrum FD, Yurochko AD. Human Cytomegalovirus Requires Epidermal Growth Factor Receptor Signaling To Enter and Initiate the Early Steps in the Establishment of Latency in CD34 + Human Progenitor Cells. J Virol 2017; 91:e01206-16. [PMID: 27974567 PMCID: PMC5309964 DOI: 10.1128/jvi.01206-16] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 12/06/2016] [Indexed: 01/11/2023] Open
Abstract
The establishment of human cytomegalovirus (HCMV) latency and persistence relies on the successful infection of hematopoietic cells, which serve as sites of viral persistence and contribute to viral spread. Here, using blocking antibodies and pharmacological inhibitors, we document that HCMV activation of the epidermal growth factor receptor (EGFR) and downstream phosphatidylinositol 3-kinase (PI3K) mediates viral entry into CD34+ human progenitor cells (HPCs), resulting in distinct cellular trafficking and nuclear translocation of the virus compared to that in other immune cells, such as we have documented in monocytes. We argue that the EGFR allows HCMV to regulate the cellular functions of these replication-restricted cells via its signaling activity following viral binding. In addition to regulating HCMV entry/trafficking, EGFR signaling may also shape the early steps required for the successful establishment of viral latency in CD34+ cells, as pharmacological inhibition of EGFR increases the transcription of lytic IE1/IE2 mRNA while curbing the expression of latency-associated UL138 mRNA. EGFR signaling following infection of CD34+ HPCs may also contribute to changes in hematopoietic potential, as treatment with the EGFR kinase (EGFRK) inhibitor AG1478 alters the expression of the cellular hematopoietic cytokine interleukin 12 (IL-12) in HCMV-infected cells but not in mock-infected cells. These findings, along with our previous work with monocytes, suggest that EGFR likely serves as an important determinant of HCMV tropism for select subsets of hematopoietic cells. Moreover, our new data suggest that EGFR is a key receptor for efficient viral entry and that the ensuing signaling regulates important early events required for successful infection of CD34+ HPCs by HCMV.IMPORTANCE HCMV establishes lifelong persistence within the majority of the human population without causing overt pathogenesis in healthy individuals. Despite this, reactivation of HCMV from its latent reservoir in the bone marrow causes significant morbidity and mortality in immunologically compromised individuals, such as bone marrow and solid organ transplant patients. Lifelong persistent infection has also been linked with the development of various cardiovascular diseases in otherwise healthy individuals. Current HCMV therapeutics target lytic replication, but not the latent viral reservoir; thus, an understanding of the molecular basis for viral latency and persistence is paramount to controlling or eliminating HCMV infection. Here, we show that the viral signalosome activated by HCMV binding to its entry receptor, EGFR, in CD34+ HPCs initiates early events necessary for successful latent infection of this cell type. EGFR and associated signaling players may therefore represent promising targets for mitigating HCMV persistence.
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Affiliation(s)
- Jung Heon Kim
- Department of Microbiology and Immunology, Center for Molecular and Tumor Virology, Center for Cardiovascular Diseases and Sciences, Louisiana State University Health Sciences Center, Shreveport, Louisiana, USA
| | - Donna Collins-McMillen
- Department of Microbiology and Immunology, Center for Molecular and Tumor Virology, Center for Cardiovascular Diseases and Sciences, Louisiana State University Health Sciences Center, Shreveport, Louisiana, USA
| | | | - Felicia D Goodrum
- BIO5 Institute, University of Arizona, Tucson, Arizona, USA
- Department of Cellular and Molecular Medicine, Department of Immunobiology, Department of Molecular and Cellular Biology, University of Arizona Cancer Center, University of Arizona, Tucson, Arizona, USA
| | - Andrew D Yurochko
- Department of Microbiology and Immunology, Center for Molecular and Tumor Virology, Center for Cardiovascular Diseases and Sciences, Louisiana State University Health Sciences Center, Shreveport, Louisiana, USA
- Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center, Shreveport, Louisiana, USA
- Center of Excellence in Arthritis and Rheumatology, Louisiana State University Health Sciences Center, Shreveport, Louisiana, USA
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21
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Shimada T, Nagata N, Okahara K, Joya A, Hayashida T, Oka S, Sakurai T, Akiyama J, Uemura N, Gatanaga H. PCR detection of human herpesviruses in colonic mucosa of individuals with inflammatory bowel disease: Comparison with individuals with immunocompetency and HIV infection. PLoS One 2017; 12:e0184699. [PMID: 28902907 PMCID: PMC5597220 DOI: 10.1371/journal.pone.0184699] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 08/29/2017] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Detection of human herpesviruses (HHVs) other than cytomegalovirus (CMV) in colonic mucosa of individuals with inflammatory bowel disease (IBD) remains unknown. This study identified eight HHVs in the colonic mucosa of individuals with IBD and compared the results with immunocompetent and human immunodeficiency virus (HIV)-infected individuals. METHODS A total of 89 individuals who had colorectal ulcer on colonoscopy were enrolled: 26 with immunocompetency (n = 26), 41 with IBD, and 22 with HIV infection. We examined the colonic ulcers for the presence of eight HHVs-herpes simplex virus (HSV)-1/2, varicella zoster virus (VZV), CMV, Epstein-Barr virus (EBV), HHV-6, HHV-7, and HHV-8-using mucosal PCR. RESULTS The IBD group had positivity rates of 0%, 0%, 0%, 53.7%, 24.4%, 39%, 39%, and 0% for HSV-1, HSV-2, VZV, EBV, CMV, HHV-6, HHV-7, and HHV-8, respectively. The positivity rates of EBV and CMV in colonic mucosa increased significantly in the order of the immunocompetent, IBD, and HIV groups (EBV: 23.1%, 53.7%, 72.7%, P for trend = 0.0005; CMV, 7.7%, 24.4%, 54.5%, P for trend = 0.0003, respectively), but no increase was found in the other HHVs. Median mucosal EBV DNA values in the immunocompetent, IBD, and HIV groups were 0, 76, and 287 copies/μg DNA, respectively (P for trend = 0.002). Corresponding median mucosal CMV DNA values were 0, 0, and 17 copies/μg DNA (P for trend = 0.0001). There was no significant difference in the positivity rates of the eight HHVs between ulcerative colitis and Crohn's disease. CONCLUSION The HHVs of EBV, CMV, HHV-6, and HHV-7, but not of HSV-1, HSV-2, VZV, or HHV-8, were identified in the colonic mucosa of IBD individuals. EBV and CMV in colonic mucosa was correlated with host immune status in increasing order of immunocompetent, IBD, and HIV-infected individuals.
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Affiliation(s)
- Takayuki Shimada
- Department of Gastroenterology and Hepatology, National Center for Global Health and Medicine, Tokyo, Japan
| | - Naoyoshi Nagata
- Department of Gastroenterology and Hepatology, National Center for Global Health and Medicine, Tokyo, Japan
- * E-mail:
| | - Koki Okahara
- Department of Gastroenterology and Hepatology, National Center for Global Health and Medicine, Tokyo, Japan
| | - Akane Joya
- AIDS Clinical Center, National Center for Global Health and Medicine, Tokyo, Japan
| | - Tsunefusa Hayashida
- AIDS Clinical Center, National Center for Global Health and Medicine, Tokyo, Japan
| | - Shinichi Oka
- AIDS Clinical Center, National Center for Global Health and Medicine, Tokyo, Japan
| | - Toshiyuki Sakurai
- Department of Gastroenterology and Hepatology, National Center for Global Health and Medicine, Tokyo, Japan
| | - Junichi Akiyama
- Department of Gastroenterology and Hepatology, National Center for Global Health and Medicine, Tokyo, Japan
| | - Naomi Uemura
- Department of Gastroenterology and Hepatology, National Center for Global Health and Medicine, Kohnodai Hospital, Chiba, Japan
| | - Hiroyuki Gatanaga
- AIDS Clinical Center, National Center for Global Health and Medicine, Tokyo, Japan
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22
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Van Damme E, Thys K, Tuefferd M, Van Hove C, Aerssens J, Van Loock M. HCMV Displays a Unique Transcriptome of Immunomodulatory Genes in Primary Monocyte-Derived Cell Types. PLoS One 2016; 11:e0164843. [PMID: 27760232 PMCID: PMC5070835 DOI: 10.1371/journal.pone.0164843] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 10/01/2016] [Indexed: 12/17/2022] Open
Abstract
Human cytomegalovirus (HCMV) is a betaherpesvirus which rarely presents problems in healthy individuals, yet may result in severe morbidity in immunocompromised patients and in immune-naïve neonates. HCMV has a large 235 kb genome with a coding capacity of at least 165 open reading frames (ORFs). This large genome allows complex gene regulation resulting in different sets of transcripts during lytic and latent infection. While latent virus mainly resides within monocytes and CD34+ progenitor cells, reactivation to lytic infection is driven by differentiation towards terminally differentiated myeloid dendritic cells and macrophages. Consequently, it has been suggested that macrophages and dendritic cells contribute to viral spread in vivo. Thus far only limited knowledge is available on the expression of HCMV genes in terminally differentiated myeloid primary cells and whether or not the virus exhibits a different set of lytic genes in primary cells compared with lytic infection in NHDF fibroblasts. To address these questions, we used Illumina next generation sequencing to determine the HCMV transcriptome in macrophages and dendritic cells during lytic infection and compared it to the transcriptome in NHDF fibroblasts. Here, we demonstrate unique expression profiles in macrophages and dendritic cells which significantly differ from the transcriptome in fibroblasts mainly by modulating the expression of viral transcripts involved in immune modulation, cell tropism and viral spread. In a head to head comparison between macrophages and dendritic cells, we observed that factors involved in viral spread and virion composition are differentially regulated suggesting that the plasticity of the virion facilitates the infection of surrounding cells. Taken together, this study provides the full transcript expression analysis of lytic HCMV genes in monocyte-derived type 1 and type 2 macrophages as well as in monocyte-derived dendritic cells. Thereby underlining the potential of HCMV to adapt to or influence different cellular environments to promote its own survival.
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Affiliation(s)
- Ellen Van Damme
- Infectious Diseases, Janssen Pharmaceutica NV, Beerse, Belgium
| | - Kim Thys
- Infectious Diseases, Janssen Pharmaceutica NV, Beerse, Belgium
| | | | - Carl Van Hove
- Discovery Sciences, Janssen Pharmaceutica NV, Beerse, Belgium
| | - Jeroen Aerssens
- Infectious Diseases, Janssen Pharmaceutica NV, Beerse, Belgium
| | - Marnix Van Loock
- Infectious Diseases, Janssen Pharmaceutica NV, Beerse, Belgium
- * E-mail:
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23
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Abstract
Herpesviruses have evolved exquisite virus-host interactions that co-opt or evade a number of host pathways to enable the viruses to persist. Persistence of human cytomegalovirus (CMV), the prototypical betaherpesvirus, is particularly complex in the host organism. Depending on host physiology and the cell types infected, CMV persistence comprises latent, chronic, and productive states that may occur concurrently. Viral latency is a central strategy by which herpesviruses ensure their lifelong persistence. Although much remains to be defined about the virus-host interactions important to CMV latency, it is clear that checkpoints composed of viral and cellular factors exist to either maintain a latent state or initiate productive replication in response to host cues. CMV offers a rich platform for defining the virus-host interactions and understanding the host biology important to viral latency. This review describes current understanding of the virus-host interactions that contribute to viral latency and reactivation.
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Affiliation(s)
- Felicia Goodrum
- Department of Immunobiology, BIO5 Institute, University of Arizona, Tucson, Arizona 85721;
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24
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Coronel R, Jesus DM, Dalle Ore L, Mymryk JS, Hertel L. Activation of Langerhans-Type Dendritic Cells Alters Human Cytomegalovirus Infection and Reactivation in a Stimulus-Dependent Manner. Front Microbiol 2016; 7:1445. [PMID: 27683575 PMCID: PMC5021960 DOI: 10.3389/fmicb.2016.01445] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 08/30/2016] [Indexed: 12/18/2022] Open
Abstract
Oral mucosal Langerhans cells (LC) are likely to play important roles in host defense against infection by human cytomegalovirus (CMV). We previously showed that in vitro-differentiated immature LC (iLC) populations contain smaller amounts of infected cells but produce higher yields than mature LC (mLC) cultures, obtained by iLC stimulation with fetal bovine serum (FBS), CD40 ligand (CD40L) and lipopolysaccharide (LPS). Here, we sought to determine if exposure to select stimuli can improve LC permissiveness to infection, if specific components of the mLC cocktail are responsible for lowering viral yields, if this is due to defects in progeny production or release, and if these restrictions are also effective against reactivated virus. None of the stimuli tested extended the proportion of infected cells to 100%, suggesting that the block to infection onset cannot be fully removed. While CD40L and FBS exerted positive effects on viral progeny production per cell, stimulation with LPS alone or in combination with CD40L was detrimental. Reductions in viral titers were not due to defects in progeny release, and the permissive or restrictive intracellular environment established upon exposure to each stimulus appeared to act in a somewhat similar way toward lytic and latent infections.
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Affiliation(s)
- Roxanne Coronel
- Center for Immunobiology and Vaccine Development, Children's Hospital Oakland Research Institute Oakland, CA, USA
| | - Desyree M Jesus
- Center for Immunobiology and Vaccine Development, Children's Hospital Oakland Research Institute Oakland, CA, USA
| | - Lucia Dalle Ore
- Center for Immunobiology and Vaccine Development, Children's Hospital Oakland Research Institute Oakland, CA, USA
| | - Joe S Mymryk
- Department of Microbiology and Immunology and Department of Oncology, The University of Western Ontario London, ON, Canada
| | - Laura Hertel
- Center for Immunobiology and Vaccine Development, Children's Hospital Oakland Research Institute Oakland, CA, USA
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25
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Inhibition of the FACT Complex Reduces Transcription from the Human Cytomegalovirus Major Immediate Early Promoter in Models of Lytic and Latent Replication. J Virol 2016; 90:4249-4253. [PMID: 26865717 DOI: 10.1128/jvi.02501-15] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 02/02/2016] [Indexed: 12/24/2022] Open
Abstract
The successful colonization of the majority of the population by human cytomegalovirus is a direct result of the virus's ability to establish and, more specifically, reactivate from latency. The underlying cellular factors involved in viral reactivation remain unknown. Here, we show that the host complexfacilitateschromatintranscription (FACT) binds to the major immediate early promoter (MIEP) and that inhibition of this complex reduces MIEP transactivation, thus inhibiting viral reactivation.
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Dupont L, Reeves MB. Cytomegalovirus latency and reactivation: recent insights into an age old problem. Rev Med Virol 2015; 26:75-89. [PMID: 26572645 DOI: 10.1002/rmv.1862] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 10/05/2015] [Indexed: 12/25/2022]
Abstract
Human cytomegalovirus (HCMV) infection remains a major cause of morbidity in patient populations. In certain clinical settings, it is the reactivation of the pre-existing latent infection in the host that poses the health risk. The prevailing view of HCMV latency was that the virus was essentially quiescent in myeloid progenitor cells and that terminal differentiation resulted in the initiation of the lytic lifecycle and reactivation of infectious virus. However, our understanding of HCMV latency and reactivation at the molecular level has been greatly enhanced through recent advancements in systems biology approaches to perform global analyses of both experimental and natural latency. These approaches, in concert with more classical reductionist experimentation, are furnishing researchers with new concepts in cytomegalovirus latency and suggest that latent infection is far more active than first thought. In this review, we will focus on new studies that suggest that distinct sites of cellular latency could exist in the human host, which, when coupled with recent observations that report different transcriptional programmes within cells of the myeloid lineage, argues for multiple latent phenotypes that could impact differently on the biology of this virus in vivo. Finally, we will also consider how the biology of the host cell where the latent infection persists further contributes to the concept of a spectrum of latent phenotypes in multiple cell types that can be exploited by the virus.
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Affiliation(s)
- Liane Dupont
- Institute of Immunity and Transplantation, University College London, London, UK
| | - Matthew B Reeves
- Institute of Immunity and Transplantation, University College London, London, UK
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Tarrant-Elorza M, Rossetto CC, Pari GS. Maintenance and replication of the human cytomegalovirus genome during latency. Cell Host Microbe 2015; 16:43-54. [PMID: 25011107 DOI: 10.1016/j.chom.2014.06.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 03/26/2014] [Accepted: 05/01/2014] [Indexed: 11/17/2022]
Abstract
Human cytomegalovirus (HCMV) can establish latent infection in hematopoietic progenitor cells (HPCs) or CD14 (+) monocytes. While circularized viral genomes are observed during latency, how viral genomes persist or which viral factors contribute to genome maintenance and/or replication is unclear. Previously, we identified a HCMV cis-acting viral maintenance element (TR element) and showed that HCMV IE1 exon 4 mRNA is expressed in latently infected HPCs. We now show that a smaller IE1 protein species (IE1x4) is expressed in latently infected HPCs. IE1x4 protein expression is required for viral genome persistence and maintenance and replication of a TR element containing plasmid (pTR). Both IE1x4 and the cellular transcription factor Sp1 interact with the TR, and inhibition of Sp1 binding abrogates pTR amplification. Further, IE1x4 interacts with Topoisomerase IIβ (TOPOIIβ), whose activity is required for pTR amplification. These results identify a HCMV latency-specific factor that promotes viral chromosome maintenance and replication.
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Affiliation(s)
- Margaret Tarrant-Elorza
- University of Nevada School of Medicine, 1664 North Virginia Street/MS320, Reno, NV 89557, USA
| | - Cyprian C Rossetto
- University of Nevada School of Medicine, 1664 North Virginia Street/MS320, Reno, NV 89557, USA
| | - Gregory S Pari
- University of Nevada School of Medicine, 1664 North Virginia Street/MS320, Reno, NV 89557, USA.
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Dynamics of Human Cytomegalovirus Infection in CD34+ Hematopoietic Cells and Derived Langerhans-Type Dendritic Cells. J Virol 2015; 89:5615-32. [PMID: 25762731 DOI: 10.1128/jvi.00305-15] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 03/02/2015] [Indexed: 12/13/2022] Open
Abstract
UNLABELLED Acquisition of human cytomegalovirus (CMV) usually occurs by contact between contaminated bodily fluids, such as urine and saliva, and host mucosal cells. Langerhans-type dendritic cells (LC) are the only type of immune cells found in the outermost layers of the oral mucosae, where they not only provide a first line of defense against CMV but can easily be targeted by orally administered vaccines, while their bone marrow resident progenitors are important sites of virus latency. In this work, we tracked the progress of infection in CD34(+) progenitor cells, immature LC (iLC), and mature LC (mLC) exposed to the clinical-like strain TB40-BAC4 or to the vaccine strain AD169varATCC, prior to their long-term maintenance under either immature or mature conditions. We show that the genomes of both strains are efficiently maintained in CD34(+) cells during their differentiation into iLC, although this requires the presence of larger amounts of input AD169varATCC DNA. Lipopolysaccharide- and CD40 ligand-induced maturation of iLC derived from latently infected progenitors was not associated with robust viral genome replication and progeny production, while maturation of directly infected iLC increased and prolonged expression of the viral immediate early proteins. While effective replication of viral genomes from both strains occurred only in mLC, both iLC and mLC produced viral progeny, suggesting that both types of LC may contribute to CMV horizontal transmission in vivo. IMPORTANCE Human CMV is usually acquired via the oral and nasal mucosae. Langerhans-type dendritic cells (LC) are the only type of immune cells found in the outermost layers of these tissues. Understanding how CMV interacts with LC and their hematopoietic progenitors is thus essential to develop innovative means of defense against this virus. Here we show that the genomes of a virulent and an attenuated strain of CMV are maintained in hematopoietic progenitor cells during their differentiation into immature LC and that maturation of these cells by exposure to lipopolysaccharide and CD40 ligand is not sufficient to trigger virus reactivation. While the extents of viral protein expression and genome replication were broadest in directly infected mature LC populations, similar amounts of viral progeny were detected in the supernatants of immature and mature LC, suggesting that these immune cells of the oral mucosa are likely to be important for CMV transmission within the human population.
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Van Damme E, Sauviller S, Lau B, Kesteleyn B, Griffiths P, Burroughs A, Emery V, Sinclair J, Van Loock M. Glucocorticosteroids trigger reactivation of human cytomegalovirus from latently infected myeloid cells and increase the risk for HCMV infection in D+R+ liver transplant patients. J Gen Virol 2014; 96:131-143. [PMID: 25312585 PMCID: PMC4268819 DOI: 10.1099/vir.0.069872-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Graft rejection in transplant patients is managed clinically by suppressing T-cell function with immunosuppressive drugs such as prednisolone and methylprednisolone. In such immunocompromised hosts, human cytomegalovirus (HCMV) is an important opportunistic pathogen and can cause severe morbidity and mortality. Currently, the effect of glucocorticosteroids (GCSs) on the HCMV life cycle remains unclear. Previous reports showed enhanced lytic replication of HCMV in vitro in the presence of GCSs. In the present study, we explored the implications of steroid exposure on latency and reactivation. We observed a direct effect of several GCSs used in the clinic on the activation of a quiescent viral major immediate-early promoter in stably transfected THP-1 monocytic cells. This activation was prevented by the glucocorticoid receptor (GR) antagonist Ru486 and by shRNA-mediated knockdown of the GR. Consistent with this observation, prednisolone treatment of latently infected primary monocytes resulted in HCMV reactivation. Analysis of the phenotype of these cells showed that treatment with GCSs was correlated with differentiation to an anti-inflammatory macrophage-like cell type. On the basis that these observations may be pertinent to HCMV reactivation in post-transplant settings, we retrospectively evaluated the incidence, viral kinetics and viral load of HCMV in liver transplant patients in the presence or absence of GCS treatment. We observed that combination therapy of baseline prednisolone and augmented methylprednisolone, upon organ rejection, significantly increased the incidence of HCMV infection in the intermediate risk group where donor and recipient are both HCMV seropositive (D+R+) to levels comparable with the high risk D+R- group.
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Affiliation(s)
- Ellen Van Damme
- Janssen Infectious Diseases BVBA, Turnhoutseweg 30, 2340 Beerse, Belgium
| | - Sarah Sauviller
- Janssen Infectious Diseases BVBA, Turnhoutseweg 30, 2340 Beerse, Belgium
| | - Betty Lau
- Department of Medicine, University of Cambridge, Level 5, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0QQ, UK
| | - Bart Kesteleyn
- Janssen Infectious Diseases BVBA, Turnhoutseweg 30, 2340 Beerse, Belgium
| | - Paul Griffiths
- Division of Infection and Immunity (Royal Free Campus), University College London, Rowland Hill Street, Hampstead, London NW3 2QG, UK
| | - Andrew Burroughs
- Sheila Sherlock Liver Centre, Royal Free NHS Trust, Hampstead, London NW3 2QG, UK
| | - Vincent Emery
- Department of Microbial and Cellular Sciences, University of Surrey, Guildford, Surrey GU2 7XH, UK.,Division of Infection and Immunity (Royal Free Campus), University College London, Rowland Hill Street, Hampstead, London NW3 2QG, UK
| | - John Sinclair
- Department of Medicine, University of Cambridge, Level 5, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0QQ, UK
| | - Marnix Van Loock
- Janssen Infectious Diseases BVBA, Turnhoutseweg 30, 2340 Beerse, Belgium
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Sinclair J, Reeves M. The intimate relationship between human cytomegalovirus and the dendritic cell lineage. Front Microbiol 2014; 5:389. [PMID: 25147545 PMCID: PMC4124589 DOI: 10.3389/fmicb.2014.00389] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 07/11/2014] [Indexed: 11/13/2022] Open
Abstract
Primary infection of healthy individuals with human cytomegalovirus (HCMV) is normally asymptomatic but results in the establishment of a lifelong infection of the host. One important cellular reservoir of HCMV latency is the CD34+ haematopoietic progenitor cells resident in the bone marrow. Viral gene expression is highly restricted in these cells with an absence of viral progeny production. However, cellular differentiation into mature myeloid cells is concomitant with the induction of a full lytic transcription program, DNA replication and, ultimately, the production of infectious viral progeny. Such reactivation of HCMV is a major cause of morbidity and mortality in a number of immune-suppressed patient populations. Our current understanding of HCMV carriage and reactivation is that cellular differentiation of the CD34+ progenitor cells through the myeloid lineage, resulting in terminal differentiation to either a macrophage or dendritic cell (DC) phenotype, is crucial for the reactivation event. In this mini-review, we focus on the interaction of HCMV with DCs, with a particular emphasis on their role in reactivation, and discuss how the critical regulation of viral major immediate-early gene expression appears to be delicately entwined with the activation of cellular pathways in differentiating DCs. Furthermore, we also explore the possible immune consequences associated with reactivation in a professional antigen presenting cell and potential countermeasures HCMV employs to abrogate these.
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Affiliation(s)
- John Sinclair
- Department of Medicine, University of Cambridge - Addenbrooke's Hospital Cambridge, UK
| | - Matthew Reeves
- Institute of Immunity and Transplantation, University College London - Royal Free Hospital Hampstead, London, UK
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Kew VG, Yuan J, Meier J, Reeves MB. Mitogen and stress activated kinases act co-operatively with CREB during the induction of human cytomegalovirus immediate-early gene expression from latency. PLoS Pathog 2014; 10:e1004195. [PMID: 24945302 PMCID: PMC4055774 DOI: 10.1371/journal.ppat.1004195] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 05/06/2014] [Indexed: 11/19/2022] Open
Abstract
The devastating clinical consequences associated with human cytomegalovirus (HCMV) infection and reactivation underscores the importance of understanding triggers of HCMV reactivation in dendritic cells (DC). Here we show that ERK-mediated reactivation is dependent on the mitogen and stress activated kinase (MSK) family. Furthermore, this MSK mediated response is dependent on CREB binding to the viral major immediate early promoter (MIEP). Specifically, CREB binding to the MIEP provides the target for MSK recruitment. Importantly, MSK mediated phosphorylation of histone H3 is required to promote histone de-methylation and the subsequent exit of HCMV from latency. Taken together, these data suggest that CREB binding to the MIEP is necessary for the recruitment of the kinase activity of MSKs to initiate the chromatin remodelling at the MIEP required for reactivation. Thus the importance of CREB during HCMV reactivation is to promote chromatin modifications conducive for viral gene expression as well as acting as a classical transcription factor. Clearly, specific inhibition of this interaction between CREB and MSKs could provide a strategy for therapeutic intervention.
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Affiliation(s)
- Verity G. Kew
- Department of Medicine, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Jinxiang Yuan
- Department of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Jeffery Meier
- Department of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Matthew B. Reeves
- Department of Medicine, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom
- Institute of Immunity & Transplantation, Division of Infection & Immunity, Royal Free Hospital, University College London, London, United Kingdom
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32
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Van Damme E, Van Loock M. Functional annotation of human cytomegalovirus gene products: an update. Front Microbiol 2014; 5:218. [PMID: 24904534 PMCID: PMC4032930 DOI: 10.3389/fmicb.2014.00218] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 04/25/2014] [Indexed: 01/31/2023] Open
Abstract
Human cytomegalovirus is an opportunistic double-stranded DNA virus with one of the largest viral genomes known. The 235 kB genome is divided in a unique long (UL) and a unique short (US) region which are flanked by terminal and internal repeats. The expression of HCMV genes is highly complex and involves the production of protein coding transcripts, polyadenylated long non-coding RNAs, polyadenylated anti-sense transcripts and a variety of non-polyadenylated RNAs such as microRNAs. Although the function of many of these transcripts is unknown, they are suggested to play a direct or regulatory role in the delicately orchestrated processes that ensure HCMV replication and life-long persistence. This review focuses on annotating the complete viral genome based on three sources of information. First, previous reviews were used as a template for the functional keywords to ensure continuity; second, the Uniprot database was used to further enrich the functional database; and finally, the literature was manually curated for novel functions of HCMV gene products. Novel discoveries were discussed in light of the viral life cycle. This functional annotation highlights still poorly understood regions of the genome but more importantly it can give insight in functional clusters and/or may be helpful in the analysis of future transcriptomics and proteomics studies.
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Affiliation(s)
- Ellen Van Damme
- Janssen Infectious Diseases BVBA, Therapeutic Area of Infectious Diseases Beerse, Belgium
| | - Marnix Van Loock
- Janssen Infectious Diseases BVBA, Therapeutic Area of Infectious Diseases Beerse, Belgium
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33
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Shi X, Sims MD, Hanna MM, Xie M, Gulick PG, Zheng YH, Basson MD, Zhang P. Neutropenia during HIV infection: adverse consequences and remedies. Int Rev Immunol 2014; 33:511-36. [PMID: 24654626 DOI: 10.3109/08830185.2014.893301] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Neutropenia frequently occurs in patients with Human immunodeficiency virus (HIV) infection. Causes for neutropenia during HIV infection are multifactoral, including the viral toxicity to hematopoietic tissue, the use of myelotoxic agents for treatment, complication with secondary infections and malignancies, as well as the patient's association with confounding factors which impair myelopoiesis. An increased prevalence and severity of neutropenia is commonly seen in advanced stages of HIV disease. Decline of neutrophil phagocytic defense in combination with the failure of adaptive immunity renders the host highly susceptible to developing fatal secondary infections. Neutropenia and myelosuppression also restrict the use of many antimicrobial agents for treatment of infections caused by HIV and opportunistic pathogens. In recent years, HIV infection has increasingly become a chronic disease because of progress in antiretroviral therapy (ART). Prevention and treatment of severe neutropenia becomes critical for improving the survival of HIV-infected patients.
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34
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Eberhardt MK, Barry PA. Pathogen manipulation of cIL-10 signaling pathways: opportunities for vaccine development? Curr Top Microbiol Immunol 2014; 380:93-128. [PMID: 25004815 DOI: 10.1007/978-3-662-43492-5_5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Interleukin-10 (IL-10) is a tightly regulated, pleiotropic cytokine that has profound effects on all facets of the immune system, eliciting cell-type-specific responses within cells expressing the IL-10 receptor (IL-10R). It is considered a master immune regulator, and imbalances in IL-10 expression, resulting from either inherent or infectious etiologies, have far reaching clinical ramifications. Regarding infectious diseases, there has been accumulating recognition that many pathogens, particularly those that establish lifelong persistence, share a commonality of their natural histories: manipulation of IL-10-mediated signaling pathways. Multiple viral, bacterial, protozoal, and fungal pathogens appear to have evolved mechanisms to co-opt normal immune functions, including those involving IL-10R-mediated signaling, and immune effector pathways away from immune-mediated protection toward environments of immune evasion, suppression, and tolerance. As a result, pathogens can persist for the life of the infected host, many of whom possess otherwise competent immune systems. Because of pathogenic avoidance of immune clearance, persistent infections can exact incalculable physical and financial costs, and represent some of the most vexing challenges for improvements in human health. Enormous benefits could be gained by the development of efficient prevention and/or therapeutic strategies that block primary infection, or clear the infection. There are now precedents that indicate that modalities focusing on pathogen-mediated manipulation of IL-10 signaling may have clinical benefit.
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Affiliation(s)
- Meghan K Eberhardt
- Center for Comparative Medicine, University of California, Davis, CA, 95616, USA
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35
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Sinclair JH, Reeves MB. Human cytomegalovirus manipulation of latently infected cells. Viruses 2013; 5:2803-24. [PMID: 24284875 PMCID: PMC3856416 DOI: 10.3390/v5112803] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 11/11/2013] [Accepted: 11/13/2013] [Indexed: 12/28/2022] Open
Abstract
Primary infection with human cytomegalovirus (HCMV) results in the establishment of a lifelong infection of the host which is aided by the ability of HCMV to undergo a latent infection. One site of HCMV latency in vivo is in haematopoietic progenitor cells, resident in the bone marrow, with genome carriage and reactivation being restricted to the cells of the myeloid lineage. Until recently, HCMV latency has been considered to be relatively quiescent with the virus being maintained essentially as a “silent partner” until conditions are met that trigger reactivation. However, advances in techniques to study global changes in gene expression have begun to show that HCMV latency is a highly active process which involves expression of specific latency-associated viral gene products which orchestrate major changes in the latently infected cell. These changes are argued to help maintain latent infection and to modulate the cellular environment to the benefit of latent virus. In this review, we will discuss these new findings and how they impact not only on our understanding of the biology of HCMV latency but also how they could provide tantalising glimpses into mechanisms that could become targets for the clearance of latent HCMV.
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Affiliation(s)
- John H. Sinclair
- Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Hills Road, Cambridge, CB2 0QQ, UK; E-Mail:
| | - Matthew B. Reeves
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College London, Royal Free Campus, Rowland Hill Street, London, NW3 2PF, UK
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +44-(0)207-794-0500 (ext. 33109)
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Circulating dendritic cells isolated from healthy seropositive donors are sites of human cytomegalovirus reactivation in vivo. J Virol 2013; 87:10660-7. [PMID: 23885077 DOI: 10.1128/jvi.01539-13] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Primary infection with human cytomegalovirus (HCMV) is generally asymptomatic in healthy individuals and results in a lifelong infection of the host. In contrast, in immunosuppressed transplant recipients and late-stage AIDS patients, HCMV infection and reactivation can result in severe disease or death. In vivo, latency is established in bone marrow CD34(+) progenitor cells with reactivation linked with their differentiation to macrophages and dendritic cells (DCs). However, previous analyses have relied on ex vivo differentiation of myeloid progenitor cells to DCs in culture. Here, we now report on the isolation and analysis of circulating blood myeloid DCs, resulting from natural differentiation in vivo, from healthy HCMV-seropositive carriers. We show that these in vivo-differentiated circulating DCs are fully permissive for HCMV and exhibit a phenotype similar to that of monocyte-derived DCs routinely used for in vitro studies of HCMV. Importantly, we also show that these DCs from healthy HCMV-seropositive donors carry HCMV genomes and, significantly, are typically positive for viral immediate-early (IE) gene expression, in contrast to circulating monocytes, which carry genomes with an absence of IE expression. Finally, we show that HCMV reactivation from these circulating DCs is enhanced by inflammatory stimuli. Overall, these data argue that the differentiation in vivo of myeloid progenitors to circulating DCs promotes the reactivation of HCMV lytic gene expression in healthy individuals, thereby providing valuable confirmation of studies performed using in vitro generation of DCs from myeloid precursors to study HCMV reactivation.
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Cis and trans acting factors involved in human cytomegalovirus experimental and natural latent infection of CD14 (+) monocytes and CD34 (+) cells. PLoS Pathog 2013; 9:e1003366. [PMID: 23717203 PMCID: PMC3662700 DOI: 10.1371/journal.ppat.1003366] [Citation(s) in RCA: 144] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 04/02/2013] [Indexed: 12/15/2022] Open
Abstract
The parameters involved in human cytomegalovirus (HCMV) latent infection in CD14 (+) and CD34 (+) cells remain poorly identified. Using next generation sequencing we deduced the transcriptome of HCMV latently infected CD14 (+) and CD34 (+) cells in experimental as well as natural latency settings. The gene expression profile from natural infection in HCMV seropositive donors closely matched experimental latency models, and included two long non-coding RNAs (lncRNAs), RNA4.9 and RNA2.7 as well as the mRNAs encoding replication factors UL84 and UL44. Chromatin immunoprecipitation assays on experimentally infected CD14 (+) monocytes followed by next generation sequencing (ChIP-Seq) were employed to demonstrate both UL84 and UL44 proteins interacted with the latent viral genome and overlapped at 5 of the 8 loci identified. RNA4.9 interacts with components of the polycomb repression complex (PRC) as well as with the MIE promoter region where the enrichment of the repressive H3K27me3 mark suggests that this lncRNA represses transcription. Formaldehyde Assisted Isolation of Regulatory Elements (FAIRE), which identifies nucleosome-depleted viral DNA, was used to confirm that latent mRNAs were associated with actively transcribed, FAIRE analysis also showed that the terminal repeat (TR) region of the latent viral genome is depleted of nucleosomes suggesting that this region may contain an element mediating viral genome maintenance. ChIP assays show that the viral TR region interacts with factors associated with the pre replication complex and a plasmid subclone containing the HCMV TR element persisted in latently infected CD14 (+) monocytes, strongly suggesting that the TR region mediates viral chromosome maintenance. Human cytomegalovirus (HCMV) is a ubiquitous herpesvirus where infection is usually subclinical. HCMV initial infection is followed by the establishment of latency in CD34 (+) myeloid cells and CD14 (+) monocytes. Primary infection or reactivation from latency can be associated with significant morbidity and mortality can occur in immune compromised patients. Latency is marked by the persistence of the viral genome, lack of production of infectious virus and the expression of only a few previously recognized latency associated transcripts. Despite the significant interest in HCMV latent infection, little is known regarding the mechanism involved in establishment or maintenance of the viral chromosome. We have now identified the transacting factors present in latently infected CD14 (+) monocytes and CD34 (+) progenitor cells as well as identification of a region of the HCMV genome, the terminal repeat locus that mediates viral DNA maintenance. This is a major step toward understanding the mechanism of HCMV latent infection.
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Hjortø GM, Kiilerich-Pedersen K, Selmeczi D, Kledal TN, Larsen NB. Human cytomegalovirus chemokine receptor US28 induces migration of cells on a CX3CL1-presenting surface. J Gen Virol 2013; 94:1111-1120. [DOI: 10.1099/vir.0.047290-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Human cytomegalovirus (HCMV)-encoded G protein-coupled-receptor US28 is believed to participate in virus dissemination through modulation of cell migration and immune evasion. US28 binds different CC chemokines and the CX3C chemokine CX3CL1. Membrane-anchored CX3CL1 is expressed by immune-activated endothelial cells, causing redirection of CX3CR1-expressing leukocytes in the blood to sites of infection. Here, we used stable transfected cell lines to examine how US28 expression affects cell migration on immobilized full-length CX3CL1, to model how HCMV-infected leukocytes interact with inflamed endothelium. We observed that US28-expressing cells migrated more than CX3CR1-expressing cells when adhering to immobilized CX3CL1. US28-induced migration was G protein-signalling dependent and was blocked by the phospholipase Cβ inhibitor U73122 and the intracellular calcium chelator BAPTA-AM. In addition, migration was inhibited in a dose-dependent manner by competition from CCL2 and CCL5, whereas CCL3 had little effect. Instead of migrating, CX3CR1-expressing cells performed ‘dancing-on-the-spot’ movements, demonstrating that anchored CX3CL1 acts as a strong tether for these cells. At low receptor expression levels, however, no significant difference in migration potential was observed when comparing the migration of CX3CR1- and US28-expressing cells. Thus, these data showed that, in contrast to CX3CR1, which promotes efficient cell capture upon binding to anchored CX3CL1, US28 acts to increase the migration of cells upon binding to the same ligand. Overall, this indicates that infected cells probably move more than uninfected cells in inflamed tissues with high CX3CL1 expression, with soluble chemokines affecting the final migration.
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Affiliation(s)
- Gertrud M. Hjortø
- Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, DK-2800 Kgs Lyngby, Denmark
| | - Katrine Kiilerich-Pedersen
- Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, DK-2800 Kgs Lyngby, Denmark
| | - David Selmeczi
- Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, DK-2800 Kgs Lyngby, Denmark
| | - Thomas N. Kledal
- Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, DK-2800 Kgs Lyngby, Denmark
| | - Niels B. Larsen
- Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, DK-2800 Kgs Lyngby, Denmark
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HCMV protein LUNA is required for viral reactivation from latently infected primary CD14⁺ cells. PLoS One 2012; 7:e52827. [PMID: 23300789 PMCID: PMC3530514 DOI: 10.1371/journal.pone.0052827] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 11/22/2012] [Indexed: 11/24/2022] Open
Abstract
Human cytomegalovirus (HCMV) is a member of the Herpesviridae family that infects individuals throughout the world. Following an initial lytic stage, HCMV can persist in the individual for life in a non-active (or latent) form. During latency, the virus resides within cells of the myeloid lineage. The mechanisms controlling HCMV latency are not completely understood. A latency associated transcript, UL81-82ast, encoding the protein LUNA (Latency Unique Natural Antigen) was identified from latently infected donors in vivo. To address the role of the UL81-82ast protein product LUNA, in the context of the viral genome, we developed a recombinant HCMV bacterial artificial chromosome (BAC) that does not express LUNA. This construct, LUNA knockout FIX virus (FIX-ΔLUNA), was used to evaluate LUNA's role in HCMV latency. The FIX-ΔLUNA virus was able to lytically infect Human Fibroblast (HF) cells, showing that LUNA is not required to establish a lytic infection. Interestingly, we observed significantly higher viral copy numbers in HF cells infected with FIX-ΔLUNA when compared to FIX-WT virus. Furthermore, FIX-WT and FIX-ΔLUNA genomic DNA and transcription of UL81-82ast persisted over time in primary monocytes. In contrast, the levels of UL138 transcript expression in FIX-ΔLUNA infected HF and CD14+ cells was 100 and 1000 fold lower (respectively) when compared to the levels observed for FIX-WT infection. Moreover, FIX-ΔLUNA virus failed to reactivate from infected CD14+ cells following differentiation. This lack of viral reactivation was accompanied by a lack of lytic gene expression, increase in viral copy numbers, and lack of the production of infectious units following differentiation of the cells. Our study suggests that the LUNA protein is involved in regulating HCMV reactivation, and that in the absence of LUNA, HCMV may not be able to enter a proper latent state and therefore cannot be rescued from the established persistent infection in CD14+ cells.
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Wen-jun L, qu-lian G, Hong-ying C, Yan Z, Mei-Xian H. Studies on HOXB4 expression during differentiation of human cytomegalovirus-infected hematopoietic stem cells into lymphocyte and erythrocyte progenitor cells. Cell Biochem Biophys 2012; 63:133-41. [PMID: 22402911 DOI: 10.1007/s12013-012-9349-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
We investigated the role of homeobox B4 (HOXB4) mRNA/protein expression induced by human cytomegalovirus (HCMV) and/or all-trans retinoic acid (ATRA) in proliferation and committed differentiation of human cord blood hematopoietic stem cells (HSCs) into colony-forming-units of T-lymphocyte (CFU-TL) and erythroid (CFU-E) progenitors in vitro. Twelve cord blood samples were collected from the fetal placenta umbilical vein and cultured in vitro. The proliferation and differentiation of cord blood HSCs into CFU-TL and CFU-E were continuously disrupted with HCMV-AD169 and/or 6 × 10(-8) mol/l of ATRA. HOXB4 mRNA/protein expression in CFU-TL and CFU-E was detected in control, ATRA, HCMV and ATRA + HCMV groups on days 3, 7, and 12 of culture by fluorescent qRT-PCR/western blot. We found that HOXB4 mRNA/protein expression was detectable on day 3, increased on day 7 and was highest on day 12. HOXB4 mRNA/protein expression in HCMV group was downregulated compared with control group (P < 0.05). However, the levels were significantly upregulated in HCMV + ATRA group compared with HCMV group (P < 0.05). We concluded that the abnormal HOXB4 mRNA/protein expression induced by HCMV could play a role in hematopoietic damage. ATRA, at the concentration used, significantly up-regulated HOXB4 mRNA/protein expression in normal lymphocyte and erythrocyte progenitor cells as well as in HCMV-infected cells.
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Affiliation(s)
- Liu Wen-jun
- Department of Pediatrics, Affiliated Hospital of Luzhou Medical College, Luzhou 646000, Sichuan Province, China.
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41
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Efficient human cytomegalovirus reactivation is maturation dependent in the Langerhans dendritic cell lineage and can be studied using a CD14+ experimental latency model. J Virol 2012; 86:8507-15. [PMID: 22647696 DOI: 10.1128/jvi.00598-12] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Studies from a number of laboratories have shown that the myeloid lineage is prominent in human cytomegalovirus (HCMV) latency, reactivation, dissemination, and pathogenesis. Existing as a latent infection in CD34(+) progenitors and circulating CD14(+) monocytes, reactivation is observed upon differentiation to mature macrophage or dendritic cell (DC) phenotypes. Langerhans' cells (LCs) are a subset of periphery resident DCs that represent a DC population likely to encounter HCMV early during primary infection. Furthermore, we have previously shown that CD34(+) derived LCs are a site of HCMV reactivation ex vivo. Accordingly, we have utilized healthy-donor CD34(+) cells to study latency and reactivation of HCMV in LCs. However, the increasing difficulty acquiring healthy-donor CD34(+) cells--particularly from seropositive donors due to the screening regimens used--led us to investigate the use of CD14(+) monocytes to generate LCs. We show here that CD14(+) monocytes cultured with transforming growth factor β generate Langerin-positive DCs (MoLCs). Consistent with observations using CD34(+) derived LCs, only mature MoLCs were permissive for HCMV infection. The lytic infection of mature MoLCs is productive and results in a marked inhibition in the capacity of these cells to promote T cell proliferation. Pertinently, differentiation of experimentally latent monocytes to the MoLC phenotype promotes reactivation in a maturation and interleukin-6 (IL-6)-dependent manner. Intriguingly, however, IL-6-mediated effects were restricted to mature LCs, in contrast to observations with classical CD14(+) derived DCs. Consequently, elucidation of the molecular basis behind the differential response of the two DC subsets should further our understanding of the fundamental mechanisms important for reactivation.
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42
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Keyes LR, Bego MG, Soland M, St Jeor S. Cyclophilin A is required for efficient human cytomegalovirus DNA replication and reactivation. J Gen Virol 2012; 93:722-732. [PMID: 22238232 DOI: 10.1099/vir.0.037309-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Human cytomegalovirus (HCMV) is a large DNA virus belonging to the subfamily Betaherpesvirinae. Haematopoietic cells of the myeloid lineage have been shown to harbour latent HCMV. However, following terminal differentiation of these cells, virus is reactivated, and in an immunocompromised host acute infection can occur. It is currently unknown which viral and cellular factors are involved in regulating the switch between lytic and latent infections. Cyclophilin A (CyPA) is a cellular protein that acts as a major factor in virus replication and/or virion maturation for a number of different viruses, including human immunodeficiency virus, hepatitis C virus, murine cytomegalovirus, influenza A virus and vaccinia virus. This study investigated the role of CyPA during HCMV infection. CyPA expression was silenced in human foreskin fibroblast (HF) and THP-1 cells using small interfering RNA (siRNA) technology, or the cells were treated with cyclosporin A (CsA) to inhibit CyPA activity. Silencing CyPA in HF cells with siRNA resulted in an overall reduction in virus production characterized by delayed expression of immediate-early (IE) proteins, decreased viral DNA loads and reduced titres. Furthermore, silencing of CyPA in THP-1 cells pre- and post-differentiation prevented IE protein expression and virus reactivation from a non-productive state. Interestingly, it was observed that treatment of THP-1 cells with CsA prevented the cells from establishing a fully latent infection. In summary, these results demonstrate that CyPA expression is an important factor in HCMV IE protein expression and virus production in lytically infected HF cells, and is a major component in virus reactivation from infected THP-1 cells.
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Affiliation(s)
- Lisa R Keyes
- Department of Microbiology and Immunology and Graduate Program in Cell and Molecular Biology, University of Nevada, Reno, NV 89557, USA
| | - Mariana G Bego
- Institut de Recherches Cliniques de Montréal (IRCM), 110 avenue des Pins Ouest, Montréal, QC H2W 1R7, Canada.,Department of Microbiology and Immunology and Graduate Program in Cell and Molecular Biology, University of Nevada, Reno, NV 89557, USA
| | - Melisa Soland
- Department of Microbiology and Immunology and Graduate Program in Cell and Molecular Biology, University of Nevada, Reno, NV 89557, USA
| | - Stephen St Jeor
- Department of Microbiology and Immunology and Graduate Program in Cell and Molecular Biology, University of Nevada, Reno, NV 89557, USA
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43
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Viral interleukin-10 expressed by human cytomegalovirus during the latent phase of infection modulates latently infected myeloid cell differentiation. J Virol 2011; 85:7465-71. [PMID: 21593144 DOI: 10.1128/jvi.00088-11] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The human cytomegalovirus UL111A gene is expressed during latent and productive infections, and it codes for homologs of interleukin-10 (IL-10). We examined whether viral IL-10 expressed during latency altered differentiation of latently infected myeloid progenitors. In comparison to infection with parental virus or mock infection, latent infection with a virus in which the gene encoding viral IL-10 has been deleted upregulated cytokines associated with dendritic cell (DC) formation and increased the proportion of myeloid DCs. These data demonstrate that viral IL-10 restricts the ability of latently infected myeloid progenitors to differentiate into DCs and identifies an immunomodulatory role for viral IL-10 which may limit the host's ability to clear latent virus.
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44
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Reeves MB. Chromatin-mediated regulation of cytomegalovirus gene expression. Virus Res 2010; 157:134-43. [PMID: 20875471 DOI: 10.1016/j.virusres.2010.09.019] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Revised: 09/17/2010] [Accepted: 09/17/2010] [Indexed: 02/03/2023]
Abstract
Following primary infection, whether Human cytomegalovirus (HCMV) enters either the latent or lytic lifecycle is dependent on the phenotype of the cell type infected. Multiple cell types are permissive for lytic infection with HCMV whereas, in contrast, well characterized sites of latency are restricted to a very specific population of CD34+ cells resident in the bone marrow and the immature myeloid cells they give rise to. It is becoming increasingly clear that one of the mechanisms that promote HCMV latency involves the recruitment of histone proteins to the major immediate early promoter (MIEP) which are subject to post-translational modifications that promote a transcriptionally inactive state. Integral to this, is the role of cellular transcriptional repressors that interact with histone modifying enzymes that promote and maintain this repressed state during latency. Crucially, the chromatin associated with the MIEP is dynamically regulated-myeloid cell differentiation triggers the acetylation of histones bound to the MIEP which is concomitant with the reactivation of IE gene expression and re-entry into lytic infection. Interestingly, this dynamic regulation of the MIEP by chromatin structure in latency extends not only into lytic infection but also for the regulation of multiple viral promoters in all phases of infection. HCMV lytic infection is characterised by a timely and co-ordinated pattern of gene expression that now has been shown to correlate with active post-translational modification of the histones associated with early and late promoters. These effects are mediated by the major IE products (IE72 and IE86) which physically and functionally interact with histone modifying enzymes resulting in the efficient activation of viral gene expression. Thus chromatin appears to play an important role in gene regulation in all phases of infection. Furthermore, these studies are highly suggestive that an intrinsic cellular anti-viral response to incoming viral genomes is to promote chromatinisation into a transcriptionally repressed state which the virus must overcome to establish a lytic infection. What is becoming evident is that chromatin structure is becoming as increasingly important for the regulation of viral gene expression as it is for cellular gene expression and thus understanding the mechanisms employed by HCMV to modulate chromatin function could have broader implications on our understanding of the control of gene expression in general.
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Affiliation(s)
- Matthew B Reeves
- Department of Medicine, University of Cambridge, Box 157, Level 5, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0QQ, UK.
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45
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Slobedman B, Cao JZ, Avdic S, Webster B, McAllery S, Cheung AK, Tan JC, Abendroth A. Human cytomegalovirus latent infection and associated viral gene expression. Future Microbiol 2010; 5:883-900. [PMID: 20521934 DOI: 10.2217/fmb.10.58] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Human cytomegalovirus (HCMV) is a clinically important and ubiquitous herpesvirus. Following primary productive infection the virus is not completely eliminated from the host, but instead establishes a lifelong latent infection without detectable virus production, from where it can reactivate at a later stage to generate new infectious virus. Reactivated HCMV often results in life-threatening disease in immunocompromised individuals, particularly allogeneic stem cell and solid organ transplant recipients, where it remains one of the most difficult opportunistic pathogens that complicate the care of these patients. The ability of HCMV to establish and reactivate from latency is central to its success as a human pathogen, yet latency remains very poorly understood. This article will cover several aspects of HCMV latency, with a focus on current understanding of viral gene expression and functions during this phase of infection.
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Affiliation(s)
- Barry Slobedman
- Centre For Virus Research, Westmead Millennium Institute & University of Sydney, Westmead Millennium Institute, PO Box 412, New South Wales 2145, Australia.
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46
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Banerjee P, Crawford L, Samuelson E, Feuer G. Hematopoietic stem cells and retroviral infection. Retrovirology 2010; 7:8. [PMID: 20132553 PMCID: PMC2826343 DOI: 10.1186/1742-4690-7-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2009] [Accepted: 02/04/2010] [Indexed: 11/10/2022] Open
Abstract
Retroviral induced malignancies serve as ideal models to help us better understand the molecular mechanisms associated with the initiation and progression of leukemogenesis. Numerous retroviruses including AEV, FLV, M-MuLV and HTLV-1 have the ability to infect hematopoietic stem and progenitor cells, resulting in the deregulation of normal hematopoiesis and the development of leukemia/lymphoma. Research over the last few decades has elucidated similarities between retroviral-induced leukemogenesis, initiated by deregulation of innate hematopoietic stem cell traits, and the cancer stem cell hypothesis. Ongoing research in some of these models may provide a better understanding of the processes of normal hematopoiesis and cancer stem cells. Research on retroviral induced leukemias and lymphomas may identify the molecular events which trigger the initial cellular transformation and subsequent maintenance of hematologic malignancies, including the generation of cancer stem cells. This review focuses on the role of retroviral infection in hematopoietic stem cells and the initiation, maintenance and progression of hematological malignancies.
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Affiliation(s)
- Prabal Banerjee
- Department of Microbiology and Immunology, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
- Center for Humanized SCID Mice and Stem Cell Processing Laboratory, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
| | - Lindsey Crawford
- Department of Microbiology and Immunology, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
| | - Elizabeth Samuelson
- Department of Microbiology and Immunology, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
| | - Gerold Feuer
- Department of Microbiology and Immunology, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
- Center for Humanized SCID Mice and Stem Cell Processing Laboratory, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
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47
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Chang WLW, Barry PA, Szubin R, Wang D, Baumgarth N. Human cytomegalovirus suppresses type I interferon secretion by plasmacytoid dendritic cells through its interleukin 10 homolog. Virology 2009; 390:330-7. [PMID: 19524994 DOI: 10.1016/j.virol.2009.05.013] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Revised: 05/05/2009] [Accepted: 05/14/2009] [Indexed: 01/06/2023]
Abstract
Type I interferons (IFNs) are innate cytokines with potent antiviral and immunoregulatory activities. It remains unclear how human cytomegalovirus (HCMV) can establish persistence in the face of these strongly antagonistic cytokines. In this study, we confirm that IFN-alpha efficiently suppresses the penetration of HCMV into susceptible cells, including monocytes, the major cell population in peripheral blood that is highly susceptible to HCMV infection. We further demonstrate that the HCMV-derived interleukin 10 (IL-10) homolog functions similar to cellular IL-10 and broadly inhibits TLR-induced transcriptional activation of IFN-alpha/beta genes in plasmacytoid dendritic cells (PDCs), a major type I IFN-producer in vivo that is highly resistant to HCMV infection in vitro. These results suggest that HCMV subverts innate immunity by suppressing type I IFN production of PDCs during primary viral infection via its IL-10 homolog.
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Affiliation(s)
- W L William Chang
- Center for Comparative Medicine, University of California, Davis, CA 95616, USA.
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48
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Hashizume H, Aoshima M, Ito T, Seo N, Takigawa M, Yagi H. Emergence of circulating monomyeloid precursors predicts reactivation of human herpesvirus-6 in drug-induced hypersensitivity syndrome. Br J Dermatol 2009; 161:486-8. [PMID: 19485994 DOI: 10.1111/j.1365-2133.2009.09280.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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49
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Focosi D, Sordi E, Papineschi F, Benedetti E, Galimberti S, Petrini M. Fatal ongoing human cytomegalovirus reactivation during high-dose melphalan and autologous stem cell transplantation. J Med Virol 2009; 81:857-860. [DOI: 10.1002/jmv.21440] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
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50
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Characterization of a novel Golgi apparatus-localized latency determinant encoded by human cytomegalovirus. J Virol 2009; 83:5615-29. [PMID: 19297488 DOI: 10.1128/jvi.01989-08] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human cytomegalovirus (HCMV) exists indefinitely in infected individuals by a yet poorly characterized latent infection in hematopoietic cells. We previously demonstrated a requirement for the putative UL138 open reading frame (ORF) in promoting a latent infection in CD34(+) hematopoietic progenitor cells (HPCs) infected in vitro. In our present study, we have identified two coterminal transcripts of 2.7 and 3.6 kb and a 21-kilodalton (kDa) protein (pUL138) that are derived from the UL138 locus with early-late gene kinetics during productive infection. The UL138 transcripts and protein are detected in both fibroblasts and HPCs. A recombinant virus, FIX-UL138(STOP), that synthesizes the UL138 transcripts but not the protein exhibited a partial loss-of-latency phenotype in HPCs, similar to the phenotype observed for the UL138-null recombinant virus. This finding suggests that the UL138 protein is required for latency, but it does not exclude the possibility that the UL138 transcripts or other ORFs also contribute to latency. The mechanisms by which pUL138 contributes to latency remain unknown. While the 86- and 72-kDa immediate-early proteins were not detected in HPCs infected with HCMV in vitro, pUL138 did not function directly to suppress expression from the major immediate-early promoter in reporter assays. Interestingly, pUL138 localizes to the Golgi apparatus in infected cells but is not incorporated into virus particles. The localization of pUL138 to the Golgi apparatus suggests that pUL138 contributes to HCMV latency by a novel mechanism. pUL138 is the first HCMV protein demonstrated to promote an infection with the hallmarks of latency in CD34(+) HPCs.
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