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Poole E, Neves TC, Oliveira MT, Sinclair J, da Silva MCC. Human Cytomegalovirus Interleukin 10 Homologs: Facing the Immune System. Front Cell Infect Microbiol 2020; 10:245. [PMID: 32582563 PMCID: PMC7296156 DOI: 10.3389/fcimb.2020.00245] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 04/27/2020] [Indexed: 12/12/2022] Open
Abstract
Human Cytomegalovirus (HCMV) can cause a variety of health disorders that can lead to death in immunocompromised individuals and neonates. The HCMV lifecycle comprises both a lytic (productive) and a latent (non-productive) phase. HCMV lytic infection occurs in a wide range of terminally differentiated cell types. HCMV latency has been less well-studied, but one characterized site of latency is in precursor cells of the myeloid lineage. All known viral genes are expressed during a lytic infection and a subset of these are also transcribed during latency. The UL111A gene which encodes the viral IL-10, a homolog of the human IL-10, is one of these genes. During infection, different transcript isoforms of UL111A are generated by alternative splicing. The most studied of the UL111A isoforms are cmvIL-10 (also termed the "A" transcript) and LAcmvIL-10 (also termed the "B" transcript), the latter being a well-characterized latency associated transcript. Both isoforms can downregulate MHC class II, however they differ in a number of other immunomodulatory properties, such as the ability to bind the IL10 receptor and induce signaling through STAT3. There are also a number of other isoforms which have been identified which are expressed by differential splicing during lytic infection termed C, D, E, F, and G, although these have been less extensively studied. HCMV uses the viral IL-10 proteins to manipulate the immune system during lytic and latent phases of infection. In this review, we will discuss the literature on the viral IL-10 transcripts identified to date, their encoded proteins and the structures of these proteins as well as the functional properties of all the different isoforms of viral IL-10.
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Affiliation(s)
- Emma Poole
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Tainan Cerqueira Neves
- Center for Natural and Humanities Sciences, Federal University of ABC (UFABC), São Bernardo do Campo, Brazil
| | - Martha Trindade Oliveira
- Center for Natural and Humanities Sciences, Federal University of ABC (UFABC), São Bernardo do Campo, Brazil
| | - John Sinclair
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
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Wilski NA, Stotesbury C, Del Casale C, Montoya B, Wong E, Sigal LJ, Snyder CM. STING Sensing of Murine Cytomegalovirus Alters the Tumor Microenvironment to Promote Antitumor Immunity. THE JOURNAL OF IMMUNOLOGY 2020; 204:2961-2972. [PMID: 32284333 DOI: 10.4049/jimmunol.1901136] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 03/18/2020] [Indexed: 01/04/2023]
Abstract
CMV has been proposed to play a role in cancer progression and invasiveness. However, CMV has been increasingly studied as a cancer vaccine vector, and multiple groups, including ours, have reported that the virus can drive antitumor immunity in certain models. Our previous work revealed that intratumoral injections of wild-type murine CMV (MCMV) into B16-F0 melanomas caused tumor growth delay in part by using a viral chemokine to recruit macrophages that were subsequently infected. We now show that MCMV acts as a STING agonist in the tumor. MCMV infection of tumors in STING-deficient mice resulted in normal recruitment of macrophages to the tumor, but poor recruitment of CD8+ T cells, reduced production of inflammatory cytokines and chemokines, and no delay in tumor growth. In vitro, expression of type I IFN was dependent on both STING and the type I IFNR. Moreover, type I IFN alone was sufficient to induce cytokine and chemokine production by macrophages and B16 tumor cells, suggesting that the major role for STING activation was to produce type I IFN. Critically, viral infection of wild-type macrophages alone was sufficient to restore tumor growth delay in STING-deficient animals. Overall, these data show that MCMV infection and sensing in tumor-associated macrophages through STING signaling is sufficient to promote antitumor immune responses in the B16-F0 melanoma model.
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Affiliation(s)
- Nicole A Wilski
- Department of Microbiology and Immunology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107
| | - Colby Stotesbury
- Department of Microbiology and Immunology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107
| | - Christina Del Casale
- Department of Microbiology and Immunology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107
| | - Brian Montoya
- Department of Microbiology and Immunology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107
| | - Eric Wong
- Department of Microbiology and Immunology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107
| | - Luis J Sigal
- Department of Microbiology and Immunology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107
| | - Christopher M Snyder
- Department of Microbiology and Immunology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107
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Ouyang P, Yang R, Yin L, Geng Y, Lai W, Huang X, Chen D, Fang J, Chen Z, Tang L, He M, Huang C, Liu W, Wang K. Molecular characterization of Cyprinid herpesvirus 3 encoded viral interleukin10. FISH & SHELLFISH IMMUNOLOGY 2019; 89:149-157. [PMID: 30926478 DOI: 10.1016/j.fsi.2019.03.048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 03/11/2019] [Accepted: 03/22/2019] [Indexed: 06/09/2023]
Abstract
Cyprinid herpesvirus 3 (CyHV-3), a virus that encodes an interleukin10 (IL-10) homologue, causes severe economic losses to the common carp and koi culture industry. The present study was devoted to this IL-10 homologue. Recombinant viral IL-10 (vIL-10) protein encoded by CyHV-3 ORF134 gene using prokaryotic expression system was obtained successfully. Bioinformatics analysis revealed that the amino acid sequence of CyHV-3 vIL-10 has low homology with other host IL-10 or viruses encoded IL-10s. However, their tertiary structure is quite similar, suggesting conservative biological functions between IL-10s and vIL-10s. The biological activity of CyHV-3 vIL-10 was detected by using CCK-8 kit and real time quantitative PCR. The results showed that CyHV-3 vIL-10 down regulate epithelioma papulosum cyprini (EPC) cellular activity at 72 h. Moreover, CyHV-3 vIL-10 inhibits the LPS-induced expression of proinflammatory genes, similar to common carp IL-10. Altogether, the results of this study demonstrate that a clear biological activity of CyHV-3 vIL-10 on its host cells and indicates CyHV-3 vIL-10 may play an important role in viral immune evasion.
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Affiliation(s)
- Ping Ouyang
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
| | - Ruixue Yang
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
| | - Lizi Yin
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
| | - Yi Geng
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
| | - Weiming Lai
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
| | - Xiaoli Huang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
| | - Defang Chen
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
| | - Jing Fang
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
| | - Zhengli Chen
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
| | - Li Tang
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
| | - Min He
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
| | - Chao Huang
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
| | - Wentao Liu
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
| | - Kaiyu Wang
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
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Schönrich G, Abdelaziz MO, Raftery MJ. Herpesviral capture of immunomodulatory host genes. Virus Genes 2017; 53:762-773. [PMID: 28451945 DOI: 10.1007/s11262-017-1460-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 04/18/2017] [Indexed: 12/27/2022]
Abstract
Herpesviruses have acquired numerous genes from their hosts. Although these homologs are not essential for viral replication, they often have important immunomodulatory functions that ensure viral persistence in the host. Some of these viral molecules are called virokines as they mimic cellular cytokines of their host such as interleukin-10 (cIL-10). In recent years, many viral homologs of IL-10 (vIL-10s) have been discovered in the genome of members of the order Herpesvirales. For some, gene and protein structure as well as biological activity and potential use in the clinical context have been explored. Besides virokines, herpesviruses have also captured genes encoding membrane-bound host immunomodulatory proteins such as major histocompatibility complex (MHC) molecules. These viral MHC mimics also retain many of the functions of the cellular genes, in particular directly or indirectly modulating the activity of natural killer cells. The mechanisms underlying capture of cellular genes by large DNA viruses are still enigmatic. In this review, we provide an update of the advances in the field of herpesviral gene piracy and discuss possible scenarios that could explain how the gene transfer from host to viral genome was achieved.
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Affiliation(s)
- Günther Schönrich
- Institute of Medical Virology, Helmut-Ruska-Haus, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany.
| | - Mohammed O Abdelaziz
- Institute of Medical Virology, Helmut-Ruska-Haus, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Martin J Raftery
- Institute of Medical Virology, Helmut-Ruska-Haus, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
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Luganini A, Terlizzi ME, Gribaudo G. Bioactive Molecules Released From Cells Infected with the Human Cytomegalovirus. Front Microbiol 2016; 7:715. [PMID: 27242736 PMCID: PMC4865657 DOI: 10.3389/fmicb.2016.00715] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 04/29/2016] [Indexed: 01/01/2023] Open
Abstract
Following primary infection in humans, the human cytomegalovirus (HCMV) persists in a latent state throughout the host’s lifetime despite a strong and efficient immune response. If the host experiences some form of immune dysregulation, such as immunosuppression or immunodeficiency, HCMV reactivates, thereby emerging from latency. Thus, in the absence of effective functional immune responses, as occurs in immunocompromised or immunoimmature individuals, both HCMV primary infections and reactivations from latency can cause significant morbidity and mortality. However, even in immunocompetent hosts, HCMV represents a relevant risk factor for the development of several chronic inflammatory diseases and certain forms of neoplasia. HCMV infection may shift between the lytic and latent state, regulated by a delicate and intricate balance between virus-mediated immunomodulation and host immune defenses. Indeed, HCMV is a master in manipulating innate and adaptive host defense pathways, and a large portion of its genome is devoted to encoding immunomodulatory proteins; such proteins may thus represent important virulence determinants. However, the pathogenesis of HCMV-related diseases is strengthened by the activities of bioactive molecules, of both viral and cellular origin, that are secreted from infected cells and collectively named as the secretome. Here, we review the state of knowledge on the composition and functions of HCMV-derived secretomes. In lytic infections of fibroblasts and different types of endothelial cells, the majority of HCMV-induced secreted proteins act in a paracrine fashion to stimulate the generation of an inflammatory microenvironment around infected cells; this may lead to vascular inflammation and angiogenesis that, in turn, foster HCMV replication and its dissemination through host tissues. Conversely, the HCMV secretome derived from latently infected hematopoietic progenitor cells induces an immunosuppressive extracellular environment that interferes with immune recognition and elimination of latently infected cells, thereby promoting viral persistence. Characterization of the composition and biological activities of HCMV secretomes from different types of infected cells will lay the foundation for future advances in our knowledge about the pathogenesis HCMV diseases and may provide targets for the development of novel antiviral intervention strategies.
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Affiliation(s)
- Anna Luganini
- Laboratory of Microbiology and Virology, Department of Life Sciences and Systems Biology, University of Turin Turin, Italy
| | - Maria E Terlizzi
- Laboratory of Microbiology and Virology, Department of Life Sciences and Systems Biology, University of Turin Turin, Italy
| | - Giorgio Gribaudo
- Laboratory of Microbiology and Virology, Department of Life Sciences and Systems Biology, University of Turin Turin, Italy
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6
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Latency-associated viral interleukin-10 (IL-10) encoded by human cytomegalovirus modulates cellular IL-10 and CCL8 Secretion during latent infection through changes in the cellular microRNA hsa-miR-92a. J Virol 2014; 88:13947-55. [PMID: 25253336 PMCID: PMC4249158 DOI: 10.1128/jvi.02424-14] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The UL111A gene of human cytomegalovirus encodes a viral homologue of the cellular immunomodulatory cytokine interleukin 10 (cIL-10), which, due to alternative splicing, results in expression of two isoforms designated LAcmvIL-10 (expressed during both lytic and latent infection) and cmvIL-10 (identified only during lytic infection). We have analyzed the functions of LAcmvIL-10 during latent infection of primary myeloid progenitor cells and found that LAcmvIL-10 is responsible, at least in part, for the known increase in secretion of cellular IL-10 and CCL8 in the secretomes of latently infected cells. This latency-associated increase in CCL8 expression results from a concomitant LAcmvIL-10-mediated suppression of the expression of the cellular microRNA (miRNA) hsa-miR-92a, which targets CCL8 directly. Taking the data together, we show that the previously observed downregulation of hsa-miR-92a and upregulation of CCL8 during HCMV latent infection of myeloid cells are intimately linked via the latency-associated expression of LAcmvIL-10. IMPORTANCE HCMV latency causes significant morbidity and mortality in immunocompromised individuals, yet HCMV is carried silently (latently) in 50 to 90% of the population. Understanding how HCMV maintains infection for the lifetime of an infected individual is critical for the treatment of immunocompromised individuals suffering with disease as a result of HCMV. In this study, we analyze one of the proteins that are expressed during the “latent” phase of HCMV, LAcmvIL-10, and find that the expression of the gene modulates the microenvironment of the infected cell, leading to evasion of the immune system.
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7
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Avdic S, McSharry BP, Slobedman B. Modulation of dendritic cell functions by viral IL-10 encoded by human cytomegalovirus. Front Microbiol 2014; 5:337. [PMID: 25071749 PMCID: PMC4081832 DOI: 10.3389/fmicb.2014.00337] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Accepted: 06/17/2014] [Indexed: 12/22/2022] Open
Abstract
Human cytomegalovirus (HCMV), a clinically important β-herpesvirus, is a master of evasion and modulation of the host immune system, including inhibition of a number of dendritic cell (DC) functions. DCs play a central role in co-ordination of the immune response against pathogens and any disturbance of DCs functions can result in a cascade effect on a range of immune cells. Recently, the HCMV gene UL111A, which encodes viral homologs of human interleukin 10, has been identified as a strong suppressor of a number of DCs functions. In this mini review, we focus on HCMV-encoded viral IL-10-mediated inhibitory effects on DCs and implications for the development of an effective HCMV vaccine.
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Affiliation(s)
- Selmir Avdic
- Human Cytomegalovirus Research Group, Discipline of Infectious Diseases and Immunology, University of Sydney Camperdown, NSW, Australia
| | - Brian P McSharry
- Human Cytomegalovirus Research Group, Discipline of Infectious Diseases and Immunology, University of Sydney Camperdown, NSW, Australia
| | - Barry Slobedman
- Human Cytomegalovirus Research Group, Discipline of Infectious Diseases and Immunology, University of Sydney Camperdown, NSW, Australia ; Centre for Virus Research, Westmead Millennium Institute Westmead, NSW, Australia
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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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9
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Ouyang P, Rakus K, van Beurden SJ, Westphal AH, Davison AJ, Gatherer D, Vanderplasschen AF. IL-10 encoded by viruses: a remarkable example of independent acquisition of a cellular gene by viruses and its subsequent evolution in the viral genome. J Gen Virol 2013; 95:245-262. [PMID: 24225498 DOI: 10.1099/vir.0.058966-0] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Many viruses have evolved strategies to deregulate the host immune system. These strategies include mechanisms to subvert or recruit the host cytokine network. IL-10 is a pleiotropic cytokine that has both immunostimulatory and immunosuppressive properties. However, its key features relate mainly to its capacity to exert potent immunosuppressive effects. Several viruses have been shown to upregulate the expression of cellular IL-10 (cIL-10) with, in some cases, enhancement of infection by suppression of immune functions. Other viruses encode functional orthologues of cIL-10, called viral IL-10s (vIL-10s). The present review is devoted to these virokines. To date, vIL-10 orthologues have been reported for 12 members of the family Herpesviridae, two members of the family Alloherpesviridae and seven members of the family Poxviridae. Study of vIL-10s demonstrated several interesting aspects on the origin and the evolution of these viral genes, e.g. the existence of multiple (potentially up to nine) independent gene acquisition events at different times during evolution, viral gene acquisition resulting from recombination with cellular genomic DNA or cDNA derived from cellular mRNA and the evolution of cellular sequence in the viral genome to restrict the biological activities of the viral orthologues to those beneficial for the virus life cycle. Here, various aspects of the vIL-10s described to date are reviewed, including their genetic organization, protein structure, origin, evolution, biological properties and potential in applied research.
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Affiliation(s)
- Ping Ouyang
- Immunology-Vaccinology (B43b), Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, University of Liège, 4000 Liège, Belgium
| | - Krzysztof Rakus
- Immunology-Vaccinology (B43b), Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, University of Liège, 4000 Liège, Belgium
| | - Steven J van Beurden
- Immunology-Vaccinology (B43b), Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, University of Liège, 4000 Liège, Belgium
| | - Adrie H Westphal
- Laboratory of Biochemistry, Department of Agrotechnology and Food Sciences, Wageningen University, Wageningen UR, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - Andrew J Davison
- MRC-University of Glasgow Centre for Virus Research, 8 Church Street, Glasgow G11 5JR, UK
| | - Derek Gatherer
- Division of Biomedical & Life Sciences, Lancaster University, Lancaster LA1 4YQ, UK.,MRC-University of Glasgow Centre for Virus Research, 8 Church Street, Glasgow G11 5JR, UK
| | - Alain F Vanderplasschen
- Immunology-Vaccinology (B43b), Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, University of Liège, 4000 Liège, Belgium
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McSharry BP, Avdic S, Slobedman B. Human cytomegalovirus encoded homologs of cytokines, chemokines and their receptors: roles in immunomodulation. Viruses 2012. [PMID: 23202490 PMCID: PMC3509658 DOI: 10.3390/v4112448] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Human cytomegalovirus (HCMV), the largest human herpesvirus, infects a majority of the world’s population. Like all herpesviruses, following primary productive infection, HCMV establishes a life-long latent infection, from which it can reactivate years later to produce new, infectious virus. Despite the presence of a massive and sustained anti-HCMV immune response, productively infected individuals can shed virus for extended periods of time, and once latent infection is established, it is never cleared from the host. It has been proposed that HCMV must therefore encode functions which help to evade immune mediated clearance during productive virus replication and latency. Molecular mimicry is a strategy used by many viruses to subvert and regulate anti-viral immunity and HCMV has hijacked/developed a range of functions that imitate host encoded immunomodulatory proteins. This review will focus on the HCMV encoded homologs of cellular cytokines/chemokines and their receptors, with an emphasis on how these virus encoded homologs may facilitate viral evasion of immune clearance.
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Affiliation(s)
- Brian P. McSharry
- Discipline of Infectious Diseases and Immunology, University of Sydney, Australia; (B.P.McS); (S.A.); (B.S.)
- Centre for Virus Research, Westmead Millennium Institute, Sydney, Australia
| | - Selmir Avdic
- Discipline of Infectious Diseases and Immunology, University of Sydney, Australia; (B.P.McS); (S.A.); (B.S.)
- Centre for Virus Research, Westmead Millennium Institute, Sydney, Australia
| | - Barry Slobedman
- Discipline of Infectious Diseases and Immunology, University of Sydney, Australia; (B.P.McS); (S.A.); (B.S.)
- Author to whom correspondence should be addressed; ; Tel.: +1-61-93514334
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Stack G, Stacey MA, Humphreys IR. Herpesvirus exploitation of host immune inhibitory pathways. Viruses 2012; 4:1182-201. [PMID: 23012619 PMCID: PMC3446756 DOI: 10.3390/v4081182] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 07/21/2012] [Accepted: 07/23/2012] [Indexed: 12/21/2022] Open
Abstract
Herpesviruses employ a plethora of mechanisms to circumvent clearance by host immune responses. A key feature of mammalian immune systems is the employment of regulatory pathways that limit immune responsiveness. The primary functions of these mechanisms are to control autoimmunity and limit exuberant responses to harmless antigen in mucosal surfaces. However, such pathways can be exploited by viral pathogens to enable acute infection, persistence and dissemination. Herein, we outline the current understanding of inhibitory pathways in modulating antiviral immunity during herpesvirus infections in vivo and discuss strategies employed by herpesviruses to exploit these pathways to limit host antiviral immunity.
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Affiliation(s)
- Gabrielle Stack
- Institute of Infection and Immunity, Cardiff University, Cardiff, CF14 4XN, UK.
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12
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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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13
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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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14
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Virus-encoded homologs of cellular interleukin-10 and their control of host immune function. J Virol 2009; 83:9618-29. [PMID: 19640997 DOI: 10.1128/jvi.01098-09] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
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