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Vlachava VM, Seirafian S, Fielding CA, Kollnberger S, Aicheler RJ, Hughes J, Baker A, Weekes MP, Forbes S, Wilkinson GWG, Wang ECY, Stanton RJ. HCMV-secreted glycoprotein gpUL4 inhibits TRAIL-mediated apoptosis and NK cell activation. Proc Natl Acad Sci U S A 2023; 120:e2309077120. [PMID: 38011551 PMCID: PMC10710050 DOI: 10.1073/pnas.2309077120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 10/07/2023] [Indexed: 11/29/2023] Open
Abstract
Human cytomegalovirus (HCMV) is a paradigm of pathogen immune evasion and sustains lifelong persistent infection in the face of exceptionally powerful host immune responses through the concerted action of multiple immune-evasins. These reduce NK cell activation by inhibiting ligands for activating receptors, expressing ligands for inhibitory receptors, or inhibiting synapse formation. However, these functions only inhibit direct interactions with the infected cell. To determine whether the virus also expresses soluble factors that could modulate NK function at a distance, we systematically screened all 170 HCMV canonical protein-coding genes. This revealed that UL4 encodes a secreted and heavily glycosylated protein (gpUL4) that is expressed with late-phase kinetics and is capable of inhibiting NK cell degranulation. Analyses of gpUL4 binding partners by mass spectrometry identified an interaction with TRAIL. gpUL4 bound TRAIL with picomolar affinity and prevented TRAIL from binding its receptor, thus acting as a TRAIL decoy receptor. TRAIL is found in both soluble and membrane-bound forms, with expression of the membrane-bound form strongly up-regulated on NK cells in response to interferon. gpUL4 inhibited apoptosis induced by soluble TRAIL, while also binding to the NK cell surface in a TRAIL-dependent manner, where it blocked NK cell degranulation and cytokine secretion. gpUL4 therefore acts as an immune-evasin by inhibiting both soluble and membrane-bound TRAIL and is a viral-encoded TRAIL decoy receptor. Interestingly, gpUL4 could also suppress NK responses to heterologous viruses, suggesting that it may act as a systemic virally encoded immunosuppressive agent.
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Affiliation(s)
- Virginia-Maria Vlachava
- Infection and Immunity, School of Medicine, Cardiff University, CardiffCF14 4XN, United Kingdom
| | - Sepehr Seirafian
- Infection and Immunity, School of Medicine, Cardiff University, CardiffCF14 4XN, United Kingdom
| | - Ceri A. Fielding
- Infection and Immunity, School of Medicine, Cardiff University, CardiffCF14 4XN, United Kingdom
| | - Simon Kollnberger
- Infection and Immunity, School of Medicine, Cardiff University, CardiffCF14 4XN, United Kingdom
| | - Rebecca J. Aicheler
- Department of Biomedical Sciences, Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, CardiffCF5 2YB, United Kingdom
| | - Joseph Hughes
- Centre for Virus Research, School of Infection & Immunity, Glasgow University, GlasgowG61 1QH, United Kingdom
| | - Alexander Baker
- Infection and Immunity, School of Medicine, Cardiff University, CardiffCF14 4XN, United Kingdom
| | - Michael P. Weekes
- Cambridge Institute for Medical Research, Department of Medicine, University of Cambridge, CambridgeCB2 0XY, United Kingdom
| | - Simone Forbes
- Infection and Immunity, School of Medicine, Cardiff University, CardiffCF14 4XN, United Kingdom
| | - Gavin W. G. Wilkinson
- Infection and Immunity, School of Medicine, Cardiff University, CardiffCF14 4XN, United Kingdom
| | - Eddie C. Y. Wang
- Infection and Immunity, School of Medicine, Cardiff University, CardiffCF14 4XN, United Kingdom
| | - Richard J. Stanton
- Infection and Immunity, School of Medicine, Cardiff University, CardiffCF14 4XN, United Kingdom
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2
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Dirck A, Diggins NL, Crawford LB, Perez WD, Parkins CJ, Struthers HH, Turner R, Pham AH, Mitchell J, Papen CR, Malouli D, Hancock MH, Caposio P. HCMV UL8 interaction with β-catenin and DVL2 regulates viral reactivation in CD34 + hematopoietic progenitor cells. J Virol 2023; 97:e0124123. [PMID: 37772824 PMCID: PMC10617580 DOI: 10.1128/jvi.01241-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 08/15/2023] [Indexed: 09/30/2023] Open
Abstract
IMPORTANCE CD34+ hematopoietic progenitor cells (HPCs) are an important cellular reservoir for latent human cytomegalovirus (HCMV). Several HCMV genes are expressed during latency that are involved with the maintenance of the viral genome in CD34+ HPC. However, little is known about the process of viral reactivation in these cells. Here, we describe a viral protein, pUL8, and its interaction and stabilization with members of the Wnt/β-catenin pathway as an important component of viral reactivation. We further define that pUL8 and β-catenin interact with DVL2 via a PDZ-binding domain, and loss of UL8 interaction with β-catenin-DVL2 restricts viral reactivation. Our findings will be instrumental in understanding the molecular processes involved in HCMV reactivation in order to design new antiviral therapeutics.
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Affiliation(s)
- Aaron Dirck
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, USA
| | - Nicole L. Diggins
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, USA
| | - Lindsey B. Crawford
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, USA
| | - Wilma D. Perez
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, USA
| | - Christopher J. Parkins
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, USA
| | - Hillary H. Struthers
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, USA
| | - Rebekah Turner
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, USA
| | - Andrew H. Pham
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, USA
| | - Jennifer Mitchell
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, USA
| | - Courtney R. Papen
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, USA
| | - Daniel Malouli
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, USA
| | - Meaghan H. Hancock
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, USA
| | - Patrizia Caposio
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, USA
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3
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Rubina A, Patel M, Nightingale K, Potts M, Fielding CA, Kollnberger S, Lau B, Ladell K, Miners KL, Nichols J, Nobre L, Roberts D, Trinca TM, Twohig JP, Vlahava VM, Davison AJ, Price DA, Tomasec P, Wilkinson GWG, Weekes MP, Stanton RJ, Wang ECY. ADAM17 targeting by human cytomegalovirus remodels the cell surface proteome to simultaneously regulate multiple immune pathways. Proc Natl Acad Sci U S A 2023; 120:e2303155120. [PMID: 37561786 PMCID: PMC10438378 DOI: 10.1073/pnas.2303155120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 06/23/2023] [Indexed: 08/12/2023] Open
Abstract
Human cytomegalovirus (HCMV) is a major human pathogen whose life-long persistence is enabled by its remarkable capacity to systematically subvert host immune defenses. In exploring the finding that HCMV infection up-regulates tumor necrosis factor receptor 2 (TNFR2), a ligand for the pro-inflammatory antiviral cytokine TNFα, we found that the underlying mechanism was due to targeting of the protease, A Disintegrin And Metalloproteinase 17 (ADAM17). ADAM17 is the prototype 'sheddase', a family of proteases that cleaves other membrane-bound proteins to release biologically active ectodomains into the supernatant. HCMV impaired ADAM17 surface expression through the action of two virally-encoded proteins in its UL/b' region, UL148 and UL148D. Proteomic plasma membrane profiling of cells infected with an HCMV double-deletion mutant for UL148 and UL148D with restored ADAM17 expression, combined with ADAM17 functional blockade, showed that HCMV stabilized the surface expression of 114 proteins (P < 0.05) in an ADAM17-dependent fashion. These included reported substrates of ADAM17 with established immunological functions such as TNFR2 and jagged1, but also numerous unreported host and viral targets, such as nectin1, UL8, and UL144. Regulation of TNFα-induced cytokine responses and NK inhibition during HCMV infection were dependent on this impairment of ADAM17. We therefore identify a viral immunoregulatory mechanism in which targeting a single sheddase enables broad regulation of multiple critical surface receptors, revealing a paradigm for viral-encoded immunomodulation.
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Affiliation(s)
- Anzelika Rubina
- Division of Infection and Immunity, School of Medicine, Cardiff University, CardiffCF14 4XN, United Kingdom
| | - Mihil Patel
- Division of Infection and Immunity, School of Medicine, Cardiff University, CardiffCF14 4XN, United Kingdom
| | - Katie Nightingale
- Cambridge Institute for Medical Research, University of Cambridge, CambridgeCB2 0XY, United Kingdom
| | - Martin Potts
- Cambridge Institute for Medical Research, University of Cambridge, CambridgeCB2 0XY, United Kingdom
- Department of Medicine, University of Cambridge, CambridgeCB2 0XY, United Kingdom
| | - Ceri A. Fielding
- Division of Infection and Immunity, School of Medicine, Cardiff University, CardiffCF14 4XN, United Kingdom
| | - Simon Kollnberger
- Division of Infection and Immunity, School of Medicine, Cardiff University, CardiffCF14 4XN, United Kingdom
| | - Betty Lau
- Centre for Virus Research, University of Glasgow, GlasgowG12 8TA, United Kingdom
| | - Kristin Ladell
- Division of Infection and Immunity, School of Medicine, Cardiff University, CardiffCF14 4XN, United Kingdom
| | - Kelly L. Miners
- Division of Infection and Immunity, School of Medicine, Cardiff University, CardiffCF14 4XN, United Kingdom
| | - Jenna Nichols
- Centre for Virus Research, University of Glasgow, GlasgowG12 8TA, United Kingdom
| | - Luis Nobre
- Cambridge Institute for Medical Research, University of Cambridge, CambridgeCB2 0XY, United Kingdom
| | - Dawn Roberts
- Division of Infection and Immunity, School of Medicine, Cardiff University, CardiffCF14 4XN, United Kingdom
| | - Terrence M. Trinca
- Division of Infection and Immunity, School of Medicine, Cardiff University, CardiffCF14 4XN, United Kingdom
| | - Jason P. Twohig
- Division of Infection and Immunity, School of Medicine, Cardiff University, CardiffCF14 4XN, United Kingdom
| | - Virginia-Maria Vlahava
- Division of Infection and Immunity, School of Medicine, Cardiff University, CardiffCF14 4XN, United Kingdom
| | - Andrew J. Davison
- Centre for Virus Research, University of Glasgow, GlasgowG12 8TA, United Kingdom
| | - David A. Price
- Division of Infection and Immunity, School of Medicine, Cardiff University, CardiffCF14 4XN, United Kingdom
| | - Peter Tomasec
- Division of Infection and Immunity, School of Medicine, Cardiff University, CardiffCF14 4XN, United Kingdom
| | - Gavin W. G. Wilkinson
- Division of Infection and Immunity, School of Medicine, Cardiff University, CardiffCF14 4XN, United Kingdom
| | - Michael P. Weekes
- Cambridge Institute for Medical Research, University of Cambridge, CambridgeCB2 0XY, United Kingdom
- Department of Medicine, University of Cambridge, CambridgeCB2 0XY, United Kingdom
| | - Richard J. Stanton
- Division of Infection and Immunity, School of Medicine, Cardiff University, CardiffCF14 4XN, United Kingdom
| | - Eddie C. Y. Wang
- Division of Infection and Immunity, School of Medicine, Cardiff University, CardiffCF14 4XN, United Kingdom
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4
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Zeng J, Cao D, Yang S, Jaijyan DK, Liu X, Wu S, Cruz-Cosme R, Tang Q, Zhu H. Insights into the Transcriptome of Human Cytomegalovirus: A Comprehensive Review. Viruses 2023; 15:1703. [PMID: 37632045 PMCID: PMC10458407 DOI: 10.3390/v15081703] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 08/03/2023] [Accepted: 08/04/2023] [Indexed: 08/27/2023] Open
Abstract
Human cytomegalovirus (HCMV) is a widespread pathogen that poses significant risks to immunocompromised individuals. Its genome spans over 230 kbp and potentially encodes over 200 open-reading frames. The HCMV transcriptome consists of various types of RNAs, including messenger RNAs (mRNAs), long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), and microRNAs (miRNAs), with emerging insights into their biological functions. HCMV mRNAs are involved in crucial viral processes, such as viral replication, transcription, and translation regulation, as well as immune modulation and other effects on host cells. Additionally, four lncRNAs (RNA1.2, RNA2.7, RNA4.9, and RNA5.0) have been identified in HCMV, which play important roles in lytic replication like bypassing acute antiviral responses, promoting cell movement and viral spread, and maintaining HCMV latency. CircRNAs have gained attention for their important and diverse biological functions, including association with different diseases, acting as microRNA sponges, regulating parental gene expression, and serving as translation templates. Remarkably, HCMV encodes miRNAs which play critical roles in silencing human genes and other functions. This review gives an overview of human cytomegalovirus and current research on the HCMV transcriptome during lytic and latent infection.
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Affiliation(s)
- Janine Zeng
- Department of Microbiology and Molecular Genetics, New Jersey Medical School, Rutgers University, 225 Warren Street, Newark, NJ 070101, USA
| | - Di Cao
- Department of Pain Medicine, Huazhong University of Science and Technology Union Shenzhen Hospital, Shenzhen 518052, China
| | - Shaomin Yang
- Department of Pain Medicine, Huazhong University of Science and Technology Union Shenzhen Hospital, Shenzhen 518052, China
| | - Dabbu Kumar Jaijyan
- Department of Microbiology and Molecular Genetics, New Jersey Medical School, Rutgers University, 225 Warren Street, Newark, NJ 070101, USA
| | - Xiaolian Liu
- Institute of Pathogenic Organisms, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
| | - Songbin Wu
- Department of Pain Medicine, Huazhong University of Science and Technology Union Shenzhen Hospital, Shenzhen 518052, China
| | - Ruth Cruz-Cosme
- Department of Microbiology, Howard University College of Medicine, 520 W Street NW, Washington, DC 20059, USA
| | - Qiyi Tang
- Department of Microbiology, Howard University College of Medicine, 520 W Street NW, Washington, DC 20059, USA
| | - Hua Zhu
- Department of Microbiology and Molecular Genetics, New Jersey Medical School, Rutgers University, 225 Warren Street, Newark, NJ 070101, USA
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5
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Inferring differential subcellular localisation in comparative spatial proteomics using BANDLE. Nat Commun 2022; 13:5948. [PMID: 36216816 PMCID: PMC9550814 DOI: 10.1038/s41467-022-33570-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 09/20/2022] [Indexed: 11/08/2022] Open
Abstract
The steady-state localisation of proteins provides vital insight into their function. These localisations are context specific with proteins translocating between different subcellular niches upon perturbation of the subcellular environment. Differential localisation, that is a change in the steady-state subcellular location of a protein, provides a step towards mechanistic insight of subcellular protein dynamics. High-accuracy high-throughput mass spectrometry-based methods now exist to map the steady-state localisation and re-localisation of proteins. Here, we describe a principled Bayesian approach, BANDLE, that uses these data to compute the probability that a protein differentially localises upon cellular perturbation. Extensive simulation studies demonstrate that BANDLE reduces the number of both type I and type II errors compared to existing approaches. Application of BANDLE to several datasets recovers well-studied translocations. In an application to cytomegalovirus infection, we obtain insights into the rewiring of the host proteome. Integration of other high-throughput datasets allows us to provide the functional context of these data.
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6
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Deciphering the Potential Coding of Human Cytomegalovirus: New Predicted Transmembrane Proteome. Int J Mol Sci 2022; 23:ijms23052768. [PMID: 35269907 PMCID: PMC8911422 DOI: 10.3390/ijms23052768] [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: 01/03/2022] [Revised: 02/18/2022] [Accepted: 02/26/2022] [Indexed: 02/06/2023] Open
Abstract
CMV is a major cause of morbidity and mortality in immunocompromised individuals that will benefit from the availability of a vaccine. Despite the efforts made during the last decade, no CMV vaccine is available. An ideal CMV vaccine should elicit a broad immune response against multiple viral antigens including proteins involved in virus-cell interaction and entry. However, the therapeutic use of neutralizing antibodies targeting glycoproteins involved in viral entry achieved only partial protection against infection. In this scenario, a better understanding of the CMV proteome potentially involved in viral entry may provide novel candidates to include in new potential vaccine design. In this study, we aimed to explore the CMV genome to identify proteins with putative transmembrane domains to identify new potential viral envelope proteins. We have performed in silico analysis using the genome sequences of nine different CMV strains to predict the transmembrane domains of the encoded proteins. We have identified 77 proteins with transmembrane domains, 39 of which were present in all the strains and were highly conserved. Among the core proteins, 17 of them such as UL10, UL139 or US33A have no ascribed function and may be good candidates for further mechanistic studies.
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7
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Lee BJ, Min CK, Hancock M, Streblow DN, Caposio P, Goodrum FD, Yurochko AD. Human Cytomegalovirus Host Interactions: EGFR and Host Cell Signaling Is a Point of Convergence Between Viral Infection and Functional Changes in Infected Cells. Front Microbiol 2021; 12:660901. [PMID: 34025614 PMCID: PMC8138183 DOI: 10.3389/fmicb.2021.660901] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 04/07/2021] [Indexed: 12/22/2022] Open
Abstract
Viruses have evolved diverse strategies to manipulate cellular signaling pathways in order to promote infection and/or persistence. Human cytomegalovirus (HCMV) possesses a number of unique properties that allow the virus to alter cellular events required for infection of a diverse array of host cell types and long-term persistence. Of specific importance is infection of bone marrow derived and myeloid lineage cells, such as peripheral blood monocytes and CD34+ hematopoietic progenitor cells (HPCs) because of their essential role in dissemination of the virus and for the establishment of latency. Viral induced signaling through the Epidermal Growth Factor Receptor (EGFR) and other receptors such as integrins are key control points for viral-induced cellular changes and productive and latent infection in host organ systems. This review will explore the current understanding of HCMV strategies utilized to hijack cellular signaling pathways, such as EGFR, to promote the wide-spread dissemination and the classic life-long herpesvirus persistence.
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Affiliation(s)
- Byeong-Jae Lee
- Department of Microbiology & Immunology, Center for Molecular and Tumor Virology, Louisiana State University Health Sciences Center Shreveport, Shreveport, LA, United States.,Center for Applied Immunology and Pathological Processes, Louisiana State University Health Sciences Center Shreveport, Shreveport, LA, United States.,Center of Excellence for Emerging Viral Threats, Louisiana State University Health Sciences Center Shreveport, Shreveport, LA, United States
| | - Chan-Ki Min
- Department of Microbiology & Immunology, Center for Molecular and Tumor Virology, Louisiana State University Health Sciences Center Shreveport, Shreveport, LA, United States.,Center for Applied Immunology and Pathological Processes, Louisiana State University Health Sciences Center Shreveport, Shreveport, LA, United States.,Center of Excellence for Emerging Viral Threats, Louisiana State University Health Sciences Center Shreveport, Shreveport, LA, United States
| | - Meaghan Hancock
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, OR, United States
| | - Daniel N Streblow
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, OR, United States
| | - Patrizia Caposio
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, OR, United States
| | | | - Andrew D Yurochko
- Department of Microbiology & Immunology, Center for Molecular and Tumor Virology, Louisiana State University Health Sciences Center Shreveport, Shreveport, LA, United States.,Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center Shreveport, Shreveport, LA, United States.,Center for Cardiovascular Diseases and Sciences, Louisiana State University Health Sciences Center Shreveport, Shreveport, LA, United States.,Center of Excellence in Arthritis and Rheumatology, Louisiana State University Health Sciences Center Shreveport, Shreveport, LA, United States
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8
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Human Cytomegalovirus and Autoimmune Diseases: Where Are We? Viruses 2021; 13:v13020260. [PMID: 33567734 PMCID: PMC7914970 DOI: 10.3390/v13020260] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 02/03/2021] [Accepted: 02/05/2021] [Indexed: 12/14/2022] Open
Abstract
Human cytomegalovirus (HCMV) is a ubiquitous double-stranded DNA virus belonging to the β-subgroup of the herpesvirus family. After the initial infection, the virus establishes latency in poorly differentiated myeloid precursors from where it can reactivate at later times to cause recurrences. In immunocompetent subjects, primary HCMV infection is usually asymptomatic, while in immunocompromised patients, HCMV infection can lead to severe, life-threatening diseases, whose clinical severity parallels the degree of immunosuppression. The existence of a strict interplay between HCMV and the immune system has led many to hypothesize that HCMV could also be involved in autoimmune diseases (ADs). Indeed, signs of active viral infection were later found in a variety of different ADs, such as rheumatological, neurological, enteric disorders, and metabolic diseases. In addition, HCMV infection has been frequently linked to increased production of autoantibodies, which play a driving role in AD progression, as observed in systemic lupus erythematosus (SLE) patients. Documented mechanisms of HCMV-associated autoimmunity include molecular mimicry, inflammation, and nonspecific B-cell activation. In this review, we summarize the available literature on the various ADs arising from or exacerbating upon HCMV infection, focusing on the potential role of HCMV-mediated immune activation at disease onset.
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9
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Human Cytomegalovirus UL7, miR-US5-1, and miR-UL112-3p Inactivation of FOXO3a Protects CD34 + Hematopoietic Progenitor Cells from Apoptosis. mSphere 2021; 6:6/1/e00986-20. [PMID: 33408225 PMCID: PMC7845589 DOI: 10.1128/msphere.00986-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Human cytomegalovirus (HCMV) infection of myeloid lineage cells, such as CD34+ hematopoietic progenitor cells (HPCs) or monocytes, results in the upregulation of antiapoptotic cellular proteins that protect the newly infected cells from programmed cell death. The mechanisms used by HCMV to regulate proapoptotic cellular proteins upon infection of CD34+ HPCs have not been fully explored. Here, we show that HCMV utilizes pUL7, a secreted protein that signals through the FLT3 receptor, and miR-US5-1 and miR-UL112-3p to reduce the abundance and activity of the proapoptotic transcription factor FOXO3a at early times after infection of CD34+ HPCs. Regulation of FOXO3a by pUL7, miR-US5-1, and miR-UL112 results in reduced expression of the proapoptotic BCL2L11 transcript and protection of CD34+ HPCs from virus-induced apoptosis. These data highlight the importance of both viral proteins and microRNAs (miRNAs) in protecting CD34+ HPCs from apoptosis at early times postinfection, allowing for the establishment of latency and maintenance of viral genome-containing cells.IMPORTANCE Human cytomegalovirus (HCMV) causes serious disease in immunocompromised individuals and is a significant problem during transplantation. The virus can establish a latent infection in CD34+ hematopoietic progenitor cells (HPCs) and periodically reactivate to cause disease in the absence of an intact immune system. What viral gene products are required for successful establishment of latency is still not fully understood. Here, we show that both a viral protein and viral miRNAs are required to prevent apoptosis after infection of CD34+ HPCs. HCMV pUL7 and miRNAs miR-US5-1 and miR-UL112-3p act to limit the expression and activation of the transcription factor FOXO3a, which in turn reduces expression of proapoptotic gene BCL2L11 and prevents virus-induced apoptosis in CD34+ HPCs.
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10
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Pang J, Slyker JA, Roy S, Bryant J, Atkinson C, Cudini J, Farquhar C, Griffiths P, Kiarie J, Morfopoulou S, Roxby AC, Tutil H, Williams R, Gantt S, Goldstein RA, Breuer J. Mixed cytomegalovirus genotypes in HIV-positive mothers show compartmentalization and distinct patterns of transmission to infants. eLife 2020; 9:e63199. [PMID: 33382036 PMCID: PMC7806273 DOI: 10.7554/elife.63199] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 12/31/2020] [Indexed: 12/15/2022] Open
Abstract
Cytomegalovirus (CMV) is the commonest cause of congenital infection and particularly so among infants born to HIV-infected women. Studies of congenital CMV infection (cCMVi) pathogenesis are complicated by the presence of multiple infecting maternal CMV strains, especially in HIV-positive women, and the large, recombinant CMV genome. Using newly developed tools to reconstruct CMV haplotypes, we demonstrate anatomic CMV compartmentalization in five HIV-infected mothers and identify the possibility of congenitally transmitted genotypes in three of their infants. A single CMV strain was transmitted in each congenitally infected case, and all were closely related to those that predominate in the cognate maternal cervix. Compared to non-transmitted strains, these congenitally transmitted CMV strains showed statistically significant similarities in 19 genes associated with tissue tropism and immunomodulation. In all infants, incident superinfections with distinct strains from breast milk were captured during follow-up. The results represent potentially important new insights into the virologic determinants of early CMV infection.
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Affiliation(s)
- Juanita Pang
- Division of Infection and Immunity, University College London, Cruciform BuildingLondonUnited Kingdom
| | - Jennifer A Slyker
- Departments of Global Health and Epidemiology, University of WashingtonSeattleUnited States
| | - Sunando Roy
- Division of Infection and Immunity, University College London, Cruciform BuildingLondonUnited Kingdom
| | - Josephine Bryant
- Division of Infection and Immunity, University College London, Cruciform BuildingLondonUnited Kingdom
| | - Claire Atkinson
- Institute of Immunology and Transplantation, Division of Infection and Immunity, University College LondonLondonUnited Kingdom
| | - Juliana Cudini
- Division of Infection and Immunity, University College London, Cruciform BuildingLondonUnited Kingdom
| | - Carey Farquhar
- Departments of Global Health, Epidemiology, Medicine (Div. Allergy and Infectious Diseases), University of WashingtonSeattleUnited States
| | - Paul Griffiths
- Institute of Immunology and Transplantation, Division of Infection and Immunity, University College LondonLondonUnited Kingdom
| | - James Kiarie
- University of Nairobi, Department of Obstetrics and Gynaecology, World Health OrganizationNairobiKenya
| | - Sofia Morfopoulou
- Division of Infection and Immunity, University College London, Cruciform BuildingLondonUnited Kingdom
| | - Alison C Roxby
- Departments of Global Health, Epidemiology, Medicine (Div. Allergy and Infectious Diseases), University of WashingtonSeattleUnited States
| | - Helena Tutil
- Division of Infection and Immunity, University College London, Cruciform BuildingLondonUnited Kingdom
| | - Rachel Williams
- Division of Infection and Immunity, University College London, Cruciform BuildingLondonUnited Kingdom
| | - Soren Gantt
- Research Centre of the Sainte-Justine University Hospital, Department of Microbiology, Infectious Diseases and Immunology, University of Montréal QCMontréalCanada
| | - Richard A Goldstein
- Division of Infection and Immunity, University College London, Cruciform BuildingLondonUnited Kingdom
| | - Judith Breuer
- Department of Infection, Immunity and Inflammation, UCL Great Ormond Street Institute of Child Health, University College LondonLondonUnited Kingdom
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11
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Chinta P, Garcia EC, Tajuddin KH, Akhidenor N, Davis A, Faure L, Spencer JV. Control of Cytokines in Latent Cytomegalovirus Infection. Pathogens 2020; 9:pathogens9100858. [PMID: 33096622 PMCID: PMC7589642 DOI: 10.3390/pathogens9100858] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/17/2020] [Accepted: 10/19/2020] [Indexed: 12/12/2022] Open
Abstract
Human cytomegalovirus (HCMV) has evolved a number of mechanisms for long-term co-existence within its host. HCMV infects a wide range of cell types, including fibroblasts, epithelial cells, monocytes, macrophages, dendritic cells, and myeloid progenitor cells. Lytic infection, with the production of infectious progeny virions, occurs in differentiated cell types, while undifferentiated myeloid precursor cells are the primary site of latent infection. The outcome of HCMV infection depends partly on the cell type and differentiation state but is also influenced by the composition of the immune environment. In this review, we discuss the role of early interactions between HCMV and the host immune system, particularly cytokine and chemokine networks, that facilitate the establishment of lifelong latent infection. A better understanding of these cytokine signaling pathways could lead to novel therapeutic targets that might prevent latency or eradicate latently infected cells.
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12
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Martínez-Vicente P, Farré D, Engel P, Angulo A. Divergent Traits and Ligand-Binding Properties of the Cytomegalovirus CD48 Gene Family. Viruses 2020; 12:v12080813. [PMID: 32731344 PMCID: PMC7472110 DOI: 10.3390/v12080813] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 07/22/2020] [Accepted: 07/24/2020] [Indexed: 12/28/2022] Open
Abstract
The genesis of gene families by the capture of host genes and their subsequent duplication is a crucial process in the evolution of large DNA viruses. CD48 is a cell surface molecule that interacts via its N-terminal immunoglobulin (Ig) domain with the cell surface receptor 2B4 (CD244), regulating leukocyte cytotoxicity. We previously reported the presence of five CD48 homologs (vCD48s) in two related cytomegaloviruses, and demonstrated that one of them, A43, binds 2B4 and acts as a soluble CD48 decoy receptor impairing NK cell function. Here, we have characterized the rest of these vCD48s. We show that they are highly glycosylated proteins that display remarkably distinct features: divergent biochemical properties, cellular locations, and temporal expression kinetics. In contrast to A43, none of them interacts with 2B4. Consistent with this, molecular modeling of the N-terminal Ig domains of these vCD48s evidences notable changes as compared to CD48, suggesting that they interact with alternative targets. Accordingly, we demonstrate that one of them, S30, tightly binds CD2, a crucial T- and NK-cell adhesion and costimulatory molecule. Thus, our findings show how a key host immune receptor gene captured by a virus can be subsequently remodeled to evolve new immunoevasins with altered binding properties.
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Affiliation(s)
- Pablo Martínez-Vicente
- Immunology Unit, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Barcelona, 08036 Barcelona, Spain; (D.F.); (P.E.)
- Correspondence: (P.M.-V.); (A.A.)
| | - Domènec Farré
- Immunology Unit, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Barcelona, 08036 Barcelona, Spain; (D.F.); (P.E.)
| | - Pablo Engel
- Immunology Unit, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Barcelona, 08036 Barcelona, Spain; (D.F.); (P.E.)
- Institut d’Investigacions Biomèdiques August Pi i Sunyer, 08036 Barcelona, Spain
| | - Ana Angulo
- Immunology Unit, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Barcelona, 08036 Barcelona, Spain; (D.F.); (P.E.)
- Institut d’Investigacions Biomèdiques August Pi i Sunyer, 08036 Barcelona, Spain
- Correspondence: (P.M.-V.); (A.A.)
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13
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Georgi F, Greber UF. The Adenovirus Death Protein - a small membrane protein controls cell lysis and disease. FEBS Lett 2020; 594:1861-1878. [PMID: 32472693 DOI: 10.1002/1873-3468.13848] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 05/20/2020] [Accepted: 05/21/2020] [Indexed: 12/16/2022]
Abstract
Human adenoviruses (HAdVs) cause widespread acute and persistent infections. Infections are usually mild and controlled by humoral and cell-based immunity. Reactivation of persistently infected immune cells can lead to a life-threatening disease in immunocompromised individuals, especially children and transplant recipients. To date, no effective therapy or vaccine against HAdV disease is available to the public. HAdV-C2 and C5 are the best-studied of more than 100 HAdV types. They persist in infected cells and release their progeny by host cell lysis to neighbouring cells and fluids, a process facilitated by the adenovirus death protein (ADP). ADP consists of about 100 amino acids and harbours a single membrane-spanning domain. It undergoes post-translational processing in endoplasmic reticulum and Golgi compartments, before localizing to the inner nuclear membrane. Here, we discuss the current knowledge on how ADP induces membrane rupture. Membrane rupture is essential for both progression of disease and efficacy of therapeutic viruses in clinical applications, in particular oncolytic therapy.
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Affiliation(s)
- Fanny Georgi
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - Urs F Greber
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
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14
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Li W, Chai H, Feng L, Deng J, Yang X, Ran Y, Li H. Generation and Application of Mouse Monoclonal Antibody Against Human Cytomegalovirus UL23. Viral Immunol 2020; 33:378-383. [PMID: 32181702 DOI: 10.1089/vim.2019.0180] [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] [Indexed: 11/12/2022] Open
Abstract
Human cytomegalovirus (HCMV) is a paradigm for pathogen-mediated immune evasion. The immune response to HCMV has been intensively studied for many years and still remains the focus of attention for numerous research groups. UL23 is an early gene of HCMV, belonging to the US22 gene family, encoding protein UL23. However, no monoclonal antibodies against to HCMV UL23 protein have been reported to prepare for the research. In this study, we prepared a highly specific monoclonal antibody against UL23 protein by alternately immunizing BALB/C mice with both UL23 recombinant protein and HCMV Towne. Recombinant protein UL23 was used as a detection antigen to screen 305 strains of hybridoma cells. One of them was identified to secrete IgG1 mAb named as 26C5. Western blotting results showed that not only the overexpressed UL23 protein in 293T cells but also the viral UL23 protein in HCMV-infected human foreskin fibroblast cells specifically were recognized by 26C5 mAb. Notably, we found that UL23 protein were enriched by 26C5 mAb in coimmunoprecipitation experiment with high potency and the native form of UL23 protein localizing primarily in the cytoplasm were recognized by 26C5 mAb in immunofluorescence assay with high specificity. The monoclonal antibody obtained in this study lays the foundation for further study of HCMV UL23 protein.
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Affiliation(s)
- Wenjing Li
- Department of Biotechnology, College of Life Science and Technology, The Key Laboratory for Virology of Guangzhou, Jinan University, Guangzhou, China
| | - Huizi Chai
- Institute of Medical Microbiology, Jinan University, Guangzhou, China
| | - Linyuan Feng
- Department of Biotechnology, College of Life Science and Technology, The Key Laboratory for Virology of Guangzhou, Jinan University, Guangzhou, China
| | - Jinfeng Deng
- Department of Biotechnology, College of Life Science and Technology, The Key Laboratory for Virology of Guangzhou, Jinan University, Guangzhou, China
| | - Xiaoping Yang
- Department of Biotechnology, College of Life Science and Technology, The Key Laboratory for Virology of Guangzhou, Jinan University, Guangzhou, China
| | - Yanhong Ran
- Department of Biotechnology, College of Life Science and Technology, The Key Laboratory for Virology of Guangzhou, Jinan University, Guangzhou, China
| | - Hongjian Li
- Department of Biotechnology, College of Life Science and Technology, The Key Laboratory for Virology of Guangzhou, Jinan University, Guangzhou, China.,Institute of Medical Microbiology, Jinan University, Guangzhou, China
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15
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Abstract
: The use of cytomegalovirus (CMV) as a vaccine vector to express antigens against multiple infectious diseases, including simian immunodeficiency virus, Ebola virus, plasmodium, and mycobacterium tuberculosis, in rhesus macaques has generated extraordinary levels of protective immunity against subsequent pathogenic challenge. Moreover, the mechanisms of immune protection have altered paradigms about viral vector-mediated immunity against ectopically expressed vaccine antigens. Further optimization of CMV-vectored vaccines, particularly as this approach moves to human clinical trials will be augmented by a more complete understanding of how CMV engenders mechanisms of immune protection. This review summarizes the particulars of the specific CMV vaccine vector that has been used to date (rhesus CMV strain 68-1) in relation to CMV natural history.
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16
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Ye L, Qian Y, Yu W, Guo G, Wang H, Xue X. Functional Profile of Human Cytomegalovirus Genes and Their Associated Diseases: A Review. Front Microbiol 2020; 11:2104. [PMID: 33013768 PMCID: PMC7498621 DOI: 10.3389/fmicb.2020.02104] [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: 05/30/2020] [Accepted: 08/10/2020] [Indexed: 12/18/2022] Open
Abstract
The human cytomegalovirus (HCMV), whose genome is 235 ± 1.9 kbp long, is a common herpesvirus. However, the functions of many of its genes are still unknown. HCMV is closely associated with various human diseases and infects 60-90% of the global population. It can infect various human cells, including fibroblasts, epithelial cells, endothelial cells, smooth muscle cells, and monocytes. Although HCMV infection is generally asymptomatic and causes subtle clinical symptoms, it can generate a robust immune response and establish a latent infection in immunocompromised individuals, including those with AIDS, transplant recipients, and developing fetuses. Currently available antivirals approved for the treatment of HCMV-associated diseases are limited by dose-limiting toxicity and the emergence of resistance; however, vaccines and immunoglobulins are unavailable. In this review, we have summarized the recent literature on 43 newly identified HCMV genes. We have described their novel functions on the viral replication cycle, latency, and host immune evasion. Further, we have discussed HCMV-associated diseases and current therapeutic targets. Our review may provide a foundational basis for studies aiming to prevent and develop targeted therapies for HCMV-associated diseases.
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Affiliation(s)
- Lele Ye
- Department of Gynecologic Oncology, Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Department of Microbiology and Immunology, Institute of Molecular Virology and Immunology, Institute of Tropical Medicine, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, China
| | - Yunyun Qian
- First Clinical College, Wenzhou Medical University, Wenzhou, China
| | - Weijie Yu
- First Clinical College, Wenzhou Medical University, Wenzhou, China
| | - Gangqiang Guo
- Department of Microbiology and Immunology, Institute of Molecular Virology and Immunology, Institute of Tropical Medicine, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, China
| | - Hong Wang
- Department of Microbiology and Immunology, Institute of Molecular Virology and Immunology, Institute of Tropical Medicine, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, China
- *Correspondence: Hong Wang, ; Xiangyang Xue,
| | - Xiangyang Xue
- Department of Microbiology and Immunology, Institute of Molecular Virology and Immunology, Institute of Tropical Medicine, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, China
- *Correspondence: Hong Wang, ; Xiangyang Xue,
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17
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Dobbins GC, Patki A, Chen D, Tiwari HK, Hendrickson C, Britt WJ, Fowler K, Chen JY, Boppana SB, Ross SA. Association of CMV genomic mutations with symptomatic infection and hearing loss in congenital CMV infection. BMC Infect Dis 2019; 19:1046. [PMID: 31822287 PMCID: PMC6905059 DOI: 10.1186/s12879-019-4681-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 11/29/2019] [Indexed: 12/23/2022] Open
Abstract
Background Congenital cytomegalovirus (cCMV) infection is the most common congenital infection and a leading cause of long-term neurological and sensory sequelae, the most common being sensorineural hearing loss (SNHL). Despite extensive research, clinical or laboratory markers to identify CMV infected children with increased risk for disease have not been identified. This study utilizes viral whole-genome next generation-sequencing (NGS) of specimens from congenitally infected infants to explore viral diversity and specific viral variants that may be associated with symptomatic infection and SNHL. Methods CMV DNA from urine specimens of 30 infants (17 asymptomatic, 13 symptomatic) was target enriched and next generation sequenced resulting in 93% coverage of the CMV genome allowing analysis of viral diversity. Results Variant frequency distribution was compared between children with symptomatic and asymptomatic cCMV and those with (n = 13) and without (n = 17) hearing loss. The CMV genes UL48A, UL88, US19 and US22 were found to have an increase in nucleotide diversity in symptomatic children; while UL57, UL20, UL104, US14, UL115, and UL35 had an increase in diversity in children with hearing loss. An analysis of single variant differences between symptomatic and asymptomatic children found UL55 to have the highest number, while the most variants associated with SNHL were in the RL11 gene family. In asymptomatic infants with SNHL, mutations were observed more frequently in UL33 and UL20. Conclusion CMV genomes from infected newborns can be mapped to 93% of the genome at a depth allowing accurate and reproducible analysis of polymorphisms for variant and gene discovery that may be linked to symptomatic and hearing loss outcomes.
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Affiliation(s)
- G Clement Dobbins
- Department of Pediatrics, The University of Alabama School of Medicine, CHB 116, 1600 6th Avenue South, Birmingham, AL, USA.
| | - Amit Patki
- Department of Biostatistics, The University of Alabama School of Public Health, Birmingham, AL, USA
| | - Dongquan Chen
- Informatics Institute, The University of Alabama at Birmingham, Birmingham, AL, USA.,Department of Medicine, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Hemant K Tiwari
- Department of Biostatistics, The University of Alabama School of Public Health, Birmingham, AL, USA
| | - Curtis Hendrickson
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - William J Britt
- Department of Pediatrics, The University of Alabama School of Medicine, CHB 116, 1600 6th Avenue South, Birmingham, AL, USA.,Informatics Institute, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Karen Fowler
- Department of Pediatrics, The University of Alabama School of Medicine, CHB 116, 1600 6th Avenue South, Birmingham, AL, USA
| | - Jake Y Chen
- Informatics Institute, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Suresh B Boppana
- Department of Pediatrics, The University of Alabama School of Medicine, CHB 116, 1600 6th Avenue South, Birmingham, AL, USA.,Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Shannon A Ross
- Department of Pediatrics, The University of Alabama School of Medicine, CHB 116, 1600 6th Avenue South, Birmingham, AL, USA. .,Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL, USA.
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18
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Subversion of natural killer cell responses by a cytomegalovirus-encoded soluble CD48 decoy receptor. PLoS Pathog 2019; 15:e1007658. [PMID: 30947296 PMCID: PMC6448830 DOI: 10.1371/journal.ppat.1007658] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 02/25/2019] [Indexed: 02/07/2023] Open
Abstract
Throughout evolution, cytomegaloviruses (CMVs) have been capturing genes from their hosts, employing the derived proteins to evade host immune defenses. We have recently reported the presence of a number of CD48 homologs (vCD48s) encoded by different pathogenic viruses, including several CMVs. However, their properties and biological relevance remain as yet unexplored. CD48, a cosignaling molecule expressed on the surface of most hematopoietic cells, modulates the function of natural killer (NK) and other cytotoxic cells by binding to its natural ligand 2B4 (CD244). Here, we have characterized A43, the vCD48 exhibiting the highest amino acid sequence identity with host CD48. A43, which is encoded by owl monkey CMV, is a soluble molecule released from the cell after being proteolytically processed through its membrane proximal region. A43 is expressed with immediate-early kinetics, yielding a protein that is rapidly detected in the supernatant of infected cells. Remarkably, surface plasmon resonance assays revealed that this viral protein binds to host 2B4 with high affinity and slow dissociation rates. We demonstrate that soluble A43 is capable to abrogate host CD48:2B4 interactions. Moreover, A43 strongly binds to human 2B4 and prevents 2B4-mediated NK-cell adhesion to target cells, therefore reducing the formation of conjugates and the establishment of immunological synapses between human NK cells and CD48-expressing target cells. Furthermore, in the presence of this viral protein, 2B4-mediated cytotoxicity and IFN-γ production by NK cells are severely impaired. In summary, we propose that A43 may serve as a functional soluble CD48 decoy receptor by binding and masking 2B4, thereby impeding effective NK cell immune control during viral infections. Thus, our findings provide a novel example of the immune evasion strategies developed by viruses. In order to evade detection and destruction by cytotoxic lymphocytes and successfully persist within their hosts, cytomegalovirus (CMVs) have evolved a number of genes dedicated to block immune recognition. Certain CMVs and other large DNA viruses encode homologs of the cell-surface molecule CD48, a ligand of the 2B4 receptor involved in regulating the function of cytotoxic lymphocytes. Here, we have investigated for the first time the immunomodulatory potential of one of these viral molecules. We show that A43, a CD48 homolog encoded by owl monkey CMV, is a soluble molecule that exhibits exceptional binding kinetics for 2B4, and is furthermore capable of blocking the interaction with its counter-receptor CD48. Moreover, we reveal how this viral protein interferes with human NK cell-mediated cytotoxicity by inhibiting the immune synapse between human NK cells and target cells. Thus, these findings not only underscore the importance of 2B4-mediated immune responses in controlling CMV infections, but also unveil the shedding of a virally-encoded soluble variant of CD48 as a new viral counteract mechanism for subverting immune surveillance.
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19
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Kolb P, Sijmons S, McArdle MR, Taher H, Womack J, Hughes C, Ventura A, Jarvis MA, Stahl-Hennig C, Hansen S, Picker LJ, Malouli D, Hengel H, Früh K. Identification and Functional Characterization of a Novel Fc Gamma-Binding Glycoprotein in Rhesus Cytomegalovirus. J Virol 2019; 93:e02077-18. [PMID: 30487278 PMCID: PMC6364020 DOI: 10.1128/jvi.02077-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 11/26/2018] [Indexed: 12/20/2022] Open
Abstract
Receptors recognizing the Fc part of immunoglobulin G (FcγRs) are key determinants in antibody-mediated immune responses. Members of the Herpesviridae interfere with this immune regulatory network by expressing viral FcγRs (vFcγRs). Human cytomegalovirus (HCMV) encodes four distinct vFcγRs that differ with respect to their IgG subtype specificity and their impact on antibody-mediated immune function in vitro The impact of vFcγRs on HCMV pathogenesis and immunomodulation in vivo is not known. The closest evolutionary animal model of HCMV is rhesus CMV (RhCMV) infection of rhesus macaques. To enable the characterization of vFcγR function in this model, we studied IgG binding by RhCMV. We show that lysates of RhCMV-infected cells contain an IgG-binding protein of 30 kDa encoded by the gene Rh05 that is a predicted type I glycoprotein belonging to the RL11 gene family. Upon deletion of Rh05, IgG-Fc binding by RhCMV strain 68-1 is lost, whereas ectopic expression of Rh05 results in IgG binding to transfected cells consistent with Rh05 being a vFcγR. Using a set of reporter cell lines stably expressing human and rhesus FcγRs, we further demonstrate that Rh05 antagonizes host FcγR activation. Compared to Rh05-intact RhCMV, RhCMVΔRh05 showed an increased activation of host FcγR upon exposure of infected cells to IgG from RhCMV-seropositive animals, suggesting that Rh05 protects infected cells from opsonization and IgG-dependent activation of host FcγRs. However, antagonizing host FcγR activation by Rh05 was not required for the establishment and maintenance of infection of RhCMV, even in a seropositive host, as shown by the induction of T cell responses to heterologous antigens expressed by RhCMV lacking the gene region encoding Rh05. In contrast to viral evasion of natural killer cells or T cell recognition, the evasion of antibody-mediated effects does not seem to be absolutely required for infection or reinfection. The identification of the first vFcγR that efficiently antagonizes host FcγR activation in the RhCMV genome will thus permit more detailed studies of this immunomodulatory mechanism in promoting viral dissemination in the presence of natural or vaccine-induced humoral immunity.IMPORTANCE Rhesus cytomegalovirus (RhCMV) offers a unique model for studying human cytomegalovirus (HCMV) pathogenesis and vaccine development. RhCMV infection of nonhuman primates greatly broadened the understanding of mechanisms by which CMVs evade or reprogram T cell and natural killer cell responses in vivo However, the role of humoral immunity and viral modulation of anti-CMV antibodies has not been studied in this model. There is evidence from in vitro studies that HCMVs can evade humoral immunity. By gene mapping and with the help of a novel cell-based reporter assay system we characterized the first RhCMV encoded IgG-Fcγ binding glycoprotein as a potent antagonist of rhesus FcγR activation. We further demonstrate that, unlike evasion of T cell immunity, this viral Fcγ receptor is not required to overcome anti-CMV immunity to establish secondary infections. These findings enable more detailed studies of the in vivo consequences of CMV evasion from IgG responses in nonhuman primate models.
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Affiliation(s)
- Philipp Kolb
- Institute of Virology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Steven Sijmons
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Matthew R McArdle
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Husam Taher
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Jennie Womack
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Colette Hughes
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Abigail Ventura
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Michael A Jarvis
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | | | - Scott Hansen
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Louis J Picker
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Daniel Malouli
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Hartmut Hengel
- Institute of Virology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Klaus Früh
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
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20
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Human Cytomegalovirus Encodes a Novel FLT3 Receptor Ligand Necessary for Hematopoietic Cell Differentiation and Viral Reactivation. mBio 2018; 9:mBio.00682-18. [PMID: 29691342 PMCID: PMC5915732 DOI: 10.1128/mbio.00682-18] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The ability of human cytomegalovirus (HCMV) to reactivate from latent infection of hematopoietic progenitor cells (HPCs) is intimately linked to cellular differentiation. HCMV encodes UL7 that our group has shown is secreted from infected cells and induces angiogenesis. In this study, we show that UL7 is a ligand for Fms-like tyrosine kinase 3 receptor (Flt-3R), a well-known critical factor in HPC differentiation. We observed that UL7 directly binds Flt-3R and induces downstream signaling cascades, including phosphatidylinositol 3-kinase (PI3K)/Akt and mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathways. Importantly, we show that UL7 protein induces differentiation of both CD34+ HPCs and CD14+ monocytes. Last, we show that an HCMV mutant lacking UL7 fails to reactivate in CD34+ HPCs in vitro as well as in humanized mice. These observations define the first virally encoded differentiation factor with significant implications not only for HCMV reactivation but also for alteration of the hematopoietic compartment in transplant patients.IMPORTANCE Human cytomegalovirus (HCMV) remains a significant cause of morbidity and mortality in allogeneic hematopoietic stem cell transplant recipients. CD34+ hematopoietic progenitor cells (HPCs) represent a critical reservoir of latent HCMV in the transplant population, thereby providing a source of virus for dissemination to visceral organs. HCMV reactivation has been linked to HPC/myeloid cellular differentiation; however, the mechanisms involved in these events are poorly understood at the molecular level. In this study, we show that a viral protein is a ligand for Fms-like tyrosine kinase 3 receptor (Flt-3R) and that the binding of HCMV UL7 to the Flt-3R triggers HPC and monocyte differentiation. Moreover, the loss of UL7 prevents viral reactivation in HPCs in vitro as well as in humanized mice. These observations define the first virally encoded differentiation factor with significant implications not only for HCMV reactivation but also for alteration of the hematopoietic compartment in transplant patients.
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