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Mackin SR, Sariol A, Diamond MS. Antibody-mediated control mechanisms of viral infections. Immunol Rev 2024. [PMID: 39162394 DOI: 10.1111/imr.13383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/21/2024]
Abstract
Antibodies generated after vaccination or natural pathogen exposure are essential mediators of protection against many infections. Most studies with viruses have focused on antibody neutralization, in which protection is conferred by the fragment antigen binding region (Fab) through targeting of different steps in the viral lifecycle including attachment, internalization, fusion, and egress. Beyond neutralization, the fragment crystallizable (Fc) region of antibodies can integrate innate and adaptive immune responses by engaging complement components and distinct Fc gamma receptors (FcγR) on different host immune cells. In this review, we discuss recent advances in our understanding of antibody neutralization and Fc effector functions, and the assays used to measure them. Additionally, we describe the contexts in which these mechanisms are associated with protection against viruses and highlight how Fc-FcγR interactions can improve the potency of antibody-based therapies.
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Affiliation(s)
- Samantha R Mackin
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Pathology & Immunology and Center for Genome Sciences, Lab & Genomic Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Alan Sariol
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Michael S Diamond
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Pathology & Immunology and Center for Genome Sciences, Lab & Genomic Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
- Andrew M. and Jane M. Bursky the Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, St. Louis, Missouri, USA
- Center for Vaccines and Immunity to Microbial Pathogens, Washington University School of Medicine, St. Louis, Missouri, USA
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2
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Otero CE, Petkova S, Ebermann M, Taher H, John N, Hoffmann K, Davalos A, Moström MJ, Gilbride RM, Papen CR, Barber-Axthelm A, Scheef EA, Barfield R, Sprehe LM, Kendall S, Manuel TD, Vande Burgt NH, Chan C, Denton M, Streblow ZJ, Streblow DN, Hansen SG, Kaur A, Permar S, Früh K, Hengel H, Malouli D, Kolb P. Rhesus Cytomegalovirus-encoded Fcγ-binding glycoproteins facilitate viral evasion from IgG-mediated humoral immunity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.27.582371. [PMID: 38464092 PMCID: PMC10925275 DOI: 10.1101/2024.02.27.582371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Human cytomegalovirus (HCMV) encodes four viral Fc-gamma receptors (vFcγRs) that counteract antibody-mediated activation in vitro , but their role in infection and pathogenesis is unknown. To examine the in vivo function of vFcγRs in animal hosts closely related to humans, we identified and characterized vFcγRs encoded by rhesus CMV (RhCMV). We demonstrate that Rh05, Rh152/151 and Rh173 represent the complete set of RhCMV vFcγRs, each displaying functional similarities to their respective HCMV orthologs with respect to antagonizing host FcγR activation in vitro . When RhCMV-naïve rhesus macaques were infected with vFcγR-deleted RhCMV, peak plasma viremia levels and anti-RhCMV antibody responses were comparable to wildtype infections. However, the duration of plasma viremia was significantly shortened in immunocompetent, but not in CD4+ T cell-depleted animals. Since vFcγRs were not required for superinfection, we conclude that vFcγRs delay control by virus-specific adaptive immune responses, particularly antibodies, during primary infection.
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3
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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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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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Ourahmane A, Hertel L, McVoy MA. The RL13 Temperance Factor Represses Replication of the Highly Cell Culture-Adapted Towne Strain of Human Cytomegalovirus. Viruses 2023; 15:1023. [PMID: 37113003 PMCID: PMC10142520 DOI: 10.3390/v15041023] [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: 12/17/2022] [Revised: 04/06/2023] [Accepted: 04/17/2023] [Indexed: 04/29/2023] Open
Abstract
Human cytomegalovirus (CMV) has evolved to replicate while causing minimal damage, maintain life-long latency, reactivate sub-clinically, and, in spite of robust host immunity, produce and shed infectious virus in order to transmit to new hosts. The CMV temperance factor RL13 may contribute to this strategy of coexistence with the host by actively restricting viral replication and spread. Viruses with an intact RL13 gene grow slowly in cell culture, release little extracellular virus, and form small foci. By contrast, viruses carrying disruptive mutations in the RL13 gene form larger foci and release higher amounts of cell-free infectious virions. Such mutations invariably arise during cell culture passage of clinical isolates and are consistently found in highly adapted strains. The potential existence in such strains of other mutations with roles in mitigating RL13's restrictive effects, however, has not been explored. To this end, a mutation that frame shifts the RL13 gene in the highly cell culture-adapted laboratory strain Towne was repaired, and a C-terminal FLAG epitope was added. Compared to the frame-shifted parental virus, viruses encoding wild-type or FLAG-tagged wild-type RL13 produced small foci and replicated poorly. Within six to ten cell culture passages, mutations emerged in RL13 that restored replication and focus size to those of the RL13-frame-shifted parental virus, implying that none of the numerous adaptive mutations acquired by strain Towne during more than 125 cell culture passages mitigate the temperance activity of RL13. Whilst RL13-FLAG expressed by passage zero stocks was localized exclusively within the virion assembly compartment, RL13-FLAG with a E208K substitution that emerged in one lineage was mostly dispersed into the cytoplasm, suggesting that localization to the virion assembly compartment is likely required for RL13 to exert its growth-restricting activities. Changes in localization also provided a convenient way to assess the emergence of RL13 mutations during serial passage, highlighting the usefulness of RL13-FLAG Towne variants for elucidating the mechanisms underlying RL13's temperance functions.
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Affiliation(s)
- Amine Ourahmane
- Department of Microbiology & Immunology, Virginia Commonwealth University, Richmond, VA 23298, USA;
| | - Laura Hertel
- Department of Pediatrics, University of California San Francisco, Oakland, CA 94609, USA;
| | - Michael A. McVoy
- Department of Pediatrics, Virginia Commonwealth University, Richmond, VA 23298, USA
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6
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Vezzani G, Pimazzoni S, Ferranti R, Calò S, Monda G, Amendola D, Frigimelica E, Maione D, Cortese M, Merola M. Human immunoglobulins are transported to HCMV viral envelope by viral Fc gamma receptors-dependent and independent mechanisms. Front Microbiol 2023; 13:1106401. [PMID: 36726564 PMCID: PMC9885202 DOI: 10.3389/fmicb.2022.1106401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 12/20/2022] [Indexed: 01/18/2023] Open
Abstract
Human cytomegaloviruses (HCMVs) employ many different mechanisms to escape and subvert the host immune system, including expression of the viral IgG Fcγ receptors (vFcγRs) RL11 (gp34), RL12 (gp95), RL13 (gpRL13), and UL119 (gp68) gene products. The role of vFcγRs in HCMV pathogenesis has been reported to operate in infected cells by interfering with IgG-mediated effector functions. We found that gp34 and gp68 are envelope proteins that bind and internalize human IgGs on the surface of infected cells. Internalized IgGs are then transported on the envelope of viral particles in a vFcR-dependent mechanism. This mechanism is also responsible for the incorporation on the virions of the anti-gH neutralizing antibody MSL-109. Intriguingly, we show that gp68 is responsible for MSL-109 incorporation, but it is dispensable for other anti-HCMV antibodies that do not need this function to be transported on mature virions. HCMV-infected cells grown in presence of anti-HCMV monoclonal antibodies generate a viral progeny still infective and possible to be neutralized. This is the first example of a virus carrying neutralizing IgGs on its surface and their possible role is discussed.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Mirko Cortese
- GSK, Siena, Italy,Department of Environmental Biological and Pharmaceutical Sciences and Technologies, University of Campania “Luigi Vanvitelli”, Caserta, Italy,Mirko Cortese, ✉
| | - Marcello Merola
- GSK, Siena, Italy,Department of Biology, University of Naples Federico II, Naples, Italy,*Correspondence: Marcello Merola, ✉
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7
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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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8
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Long X, Qiu Y, Zhang Z, Wu M. Insight for Immunotherapy of HCMV Infection. Int J Biol Sci 2021; 17:2899-2911. [PMID: 34345215 PMCID: PMC8326118 DOI: 10.7150/ijbs.58127] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Accepted: 06/30/2021] [Indexed: 12/29/2022] Open
Abstract
Human cytomegalovirus (HCMV), a ubiquitous in humans, has a high prevalence rate. Young people are susceptible to HCMV infection in developing countries, while older individuals are more susceptible in developed countries. Most patients have no obvious symptoms from the primary infection. Studies have indicated that the virus has gradually adapted to the host immune system. Therefore, the control of HCMV infection requires strong immune modulation. With the recent advances in immunotherapy, its application to HCMV infections is receiving increasing attention. Here, we discuss the immune response to HCMV infection, the immune escape mechanism, and the different roles that HCMV plays in various types of immunotherapy, including vaccines, adoptive cell therapy, checkpoint blockade therapy, and targeted antibodies.
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Affiliation(s)
- Xinmiao Long
- Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha 410013, Hunan, China
- The Key Laboratory of Carcinogenesis of the Chinese Ministry of Health, The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, 410008 , Hunan, China
- Department of Pathogeny Biology, School of Basic Medical Science, Central South University, Changsha, 410078, Hunan, China
| | - Yi Qiu
- Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha 410013, Hunan, China
- The Key Laboratory of Carcinogenesis of the Chinese Ministry of Health, The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, 410008 , Hunan, China
- Department of Pathogeny Biology, School of Basic Medical Science, Central South University, Changsha, 410078, Hunan, China
| | - Zuping Zhang
- Department of Pathogeny Biology, School of Basic Medical Science, Central South University, Changsha, 410078, Hunan, China
| | - Minghua Wu
- Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha 410013, Hunan, China
- The Key Laboratory of Carcinogenesis of the Chinese Ministry of Health, The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, 410008 , Hunan, China
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The Zinc Finger Antiviral Protein ZAP Restricts Human Cytomegalovirus and Selectively Binds and Destabilizes Viral UL4/ UL5 Transcripts. mBio 2021; 12:mBio.02683-20. [PMID: 33947766 PMCID: PMC8263000 DOI: 10.1128/mbio.02683-20] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Interferon-stimulated gene products (ISGs) play a crucial role in early infection control. The ISG zinc finger CCCH-type antiviral protein 1 (ZAP/ZC3HAV1) antagonizes several RNA viruses by binding to CG-rich RNA sequences, whereas its effect on DNA viruses is less well understood. Here, we decipher the role of ZAP in the context of human cytomegalovirus (HCMV) infection, a β-herpesvirus that is associated with high morbidity in immunosuppressed individuals and newborns. We show that expression of the two major isoforms of ZAP, ZAP-S and ZAP-L, is induced during HCMV infection and that both negatively affect HCMV replication. Transcriptome and proteome analyses demonstrated that the expression of ZAP results in reduced viral mRNA and protein levels and decelerates the progression of HCMV infection. Metabolic RNA labeling combined with high-throughput sequencing (SLAM-seq) revealed that most of the gene expression changes late in infection result from the general attenuation of HCMV. Furthermore, at early stages of infection, ZAP restricts HCMV by destabilizing a distinct subset of viral mRNAs, particularly those from the previously uncharacterized UL4-UL6 HCMV gene locus. Through enhanced cross-linking immunoprecipitation and sequencing analysis (eCLIP-seq), we identified the transcripts expressed from this HCMV locus as the direct targets of ZAP. Moreover, our data show that ZAP preferentially recognizes not only CG, but also other cytosine-rich sequences, thereby expanding its target specificity. In summary, this report is the first to reveal direct targets of ZAP during HCMV infection, which strongly indicates that transcripts from the UL4-UL6 locus may play an important role for HCMV replication.IMPORTANCE Viral infections have a large impact on society, leading to major human and economic losses and even global instability. So far, many viral infections, including human cytomegalovirus (HCMV) infection, are treated with a small repertoire of drugs, often accompanied by the occurrence of resistant mutants. There is no licensed HCMV vaccine in sight to protect those most at risk, particularly immunocompromised individuals or pregnant women who might otherwise transmit the virus to the fetus. Thus, the identification of novel intervention strategies is urgently required. In this study, we show that ZAP decelerates the viral gene expression cascade, presumably by selectively handpicking a distinct set of viral transcripts for degradation. Our study illustrates the potent role of ZAP as an HCMV restriction factor and sheds light on a possible role for UL4 and/or UL5 early during infection, paving a new avenue for the exploration of potential targets for novel therapies.
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10
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Kolb P, Hoffmann K, Sievert A, Reinhard H, Merce-Maldonado E, Le-Trilling VTK, Halenius A, Gütle D, Hengel H. Human cytomegalovirus antagonizes activation of Fcγ receptors by distinct and synergizing modes of IgG manipulation. eLife 2021; 10:63877. [PMID: 33724188 PMCID: PMC8041466 DOI: 10.7554/elife.63877] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 03/15/2021] [Indexed: 01/19/2023] Open
Abstract
Human cytomegalovirus (HCMV) is endowed with multiple highly sophisticated immune evasion strategies. This includes the evasion from antibody mediated immune control by counteracting host Fc-gamma receptor (FcγR) mediated immune control mechanisms such as antibody-dependent cellular cytotoxicity (ADCC). We have previously shown that HCMV avoids FcγR activation by concomitant expression of the viral Fc-gamma-binding glycoproteins (vFcγRs) gp34 and gp68. We now show that gp34 and gp68 bind IgG simultaneously at topologically different Fcγ sites and achieve efficient antagonization of host FcγR activation by distinct but synergizing mechanisms. While gp34 enhances immune complex internalization, gp68 acts as inhibitor of host FcγR binding to immune complexes. In doing so, gp68 induces Fcγ accessibility to gp34 and simultaneously limits host FcγR recognition. The synergy of gp34 and gp68 is compelled by the interfering influence of excessive non-immune IgG ligands and highlights conformational changes within the IgG globular chains critical for antibody effector function. Human cytomegalovirus is a type of herpes virus that rarely causes symptoms in healthy people but can cause serious complications in unborn babies and in people with compromised immune systems, such as transplant recipients. The virus has found ways to successfully evade the immune system, and once infected, the body retains the virus for life. It deploys an arsenal of proteins that bind to antibodies, specialized proteins the immune system uses to flag virus-infected cells for destruction. This prevents certain cells of the immune system, the natural killer cells, from recognizing and destroying virus-infected cells. These immune-evading proteins are called viral Fc-gamma receptors, or vFcγRs. While it has been previously shown that these receptors are able to evade the immune system, it remained unknown how exactly they prevent natural killer cells from recognizing infected cells. Now, Kolb et al. show that the cytomegalovirus deploys two vFcγRs called gp34 and gp68, which work together to block natural killer cells. The latter reduces the ability of natural killer cells to bind to antibodies on cytomegalovirus-infected cells. This paves the way for gp34 to pull virus proteins from the surface of the infected cell, making them inaccessible to the immune system. Neither protein fully protects virus-infected cells on its own, but together they are highly effective. The experiments reveal further details about how cytomegalovirus uses two defense mechanisms simultaneously to outmaneuver the immune system. Understanding this two-part viral evasion system may help scientists to develop vaccines or new treatments that can protect vulnerable people from diseases caused by the cytomegalovirus.
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Affiliation(s)
- Philipp Kolb
- Faculty of Medicine, Albert-Ludwigs-University Freiburg, Freiburg, Germany.,Institute of Virology, University Medical Center, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Katja Hoffmann
- Faculty of Medicine, Albert-Ludwigs-University Freiburg, Freiburg, Germany.,Institute of Virology, University Medical Center, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Annika Sievert
- Faculty of Medicine, Albert-Ludwigs-University Freiburg, Freiburg, Germany.,Institute of Virology, University Medical Center, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Henrike Reinhard
- Institute of Virology, University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Eva Merce-Maldonado
- Institute of Virology, University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | | | - Anne Halenius
- Faculty of Medicine, Albert-Ludwigs-University Freiburg, Freiburg, Germany.,Institute of Virology, University Medical Center, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Dominique Gütle
- Faculty of Medicine, Albert-Ludwigs-University Freiburg, Freiburg, Germany.,Institute of Virology, University Medical Center, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Hartmut Hengel
- Faculty of Medicine, Albert-Ludwigs-University Freiburg, Freiburg, Germany.,Institute of Virology, University Medical Center, Albert-Ludwigs-University Freiburg, Freiburg, Germany
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11
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Gugliesi F, Pasquero S, Griffante G, Scutera S, Albano C, Pacheco SFC, Riva G, Dell’Oste V, Biolatti M. Human Cytomegalovirus and Autoimmune Diseases: Where Are We? Viruses 2021; 13:260. [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] [MESH Headings] [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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Affiliation(s)
- Francesca Gugliesi
- Department of Public Health and Pediatric Sciences, University of Turin, 10126 Turin, Italy; (F.G.); (S.P.); (S.S.); (C.A.); (S.F.C.P.); (V.D.)
| | - Selina Pasquero
- Department of Public Health and Pediatric Sciences, University of Turin, 10126 Turin, Italy; (F.G.); (S.P.); (S.S.); (C.A.); (S.F.C.P.); (V.D.)
| | - Gloria Griffante
- Department of Translational Medicine, Molecular Virology Unit, University of Piemonte Orientale Medical School, 28100 Novara, Italy;
| | - Sara Scutera
- Department of Public Health and Pediatric Sciences, University of Turin, 10126 Turin, Italy; (F.G.); (S.P.); (S.S.); (C.A.); (S.F.C.P.); (V.D.)
| | - Camilla Albano
- Department of Public Health and Pediatric Sciences, University of Turin, 10126 Turin, Italy; (F.G.); (S.P.); (S.S.); (C.A.); (S.F.C.P.); (V.D.)
| | - Sergio Fernando Castillo Pacheco
- Department of Public Health and Pediatric Sciences, University of Turin, 10126 Turin, Italy; (F.G.); (S.P.); (S.S.); (C.A.); (S.F.C.P.); (V.D.)
| | - Giuseppe Riva
- Otorhinolaryngology Division, Department of Surgical Sciences, University of Turin, 10126 Turin, Italy;
| | - Valentina Dell’Oste
- Department of Public Health and Pediatric Sciences, University of Turin, 10126 Turin, Italy; (F.G.); (S.P.); (S.S.); (C.A.); (S.F.C.P.); (V.D.)
| | - Matteo Biolatti
- Department of Public Health and Pediatric Sciences, University of Turin, 10126 Turin, Italy; (F.G.); (S.P.); (S.S.); (C.A.); (S.F.C.P.); (V.D.)
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12
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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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13
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Taher H, Mahyari E, Kreklywich C, Uebelhoer LS, McArdle MR, Moström MJ, Bhusari A, Nekorchuk M, E X, Whitmer T, Scheef EA, Sprehe LM, Roberts DL, Hughes CM, Jackson KA, Selseth AN, Ventura AB, Cleveland-Rubeor HC, Yue Y, Schmidt KA, Shao J, Edlefsen PT, Smedley J, Kowalik TF, Stanton RJ, Axthelm MK, Estes JD, Hansen SG, Kaur A, Barry PA, Bimber BN, Picker LJ, Streblow DN, Früh K, Malouli D. In vitro and in vivo characterization of a recombinant rhesus cytomegalovirus containing a complete genome. PLoS Pathog 2020; 16:e1008666. [PMID: 33232376 PMCID: PMC7723282 DOI: 10.1371/journal.ppat.1008666] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 12/08/2020] [Accepted: 09/30/2020] [Indexed: 02/07/2023] Open
Abstract
Cytomegaloviruses (CMVs) are highly adapted to their host species resulting in strict species specificity. Hence, in vivo examination of all aspects of CMV biology employs animal models using host-specific CMVs. Infection of rhesus macaques (RM) with rhesus CMV (RhCMV) has been established as a representative model for infection of humans with HCMV due to the close evolutionary relationships of both host and virus. However, the only available RhCMV clone that permits genetic modifications is based on the 68-1 strain which has been passaged in fibroblasts for decades resulting in multiple genomic changes due to tissue culture adaptations. As a result, 68-1 displays reduced viremia in RhCMV-naïve animals and limited shedding compared to non-clonal, low passage isolates. To overcome this limitation, we used sequence information from primary RhCMV isolates to construct a full-length (FL) RhCMV by repairing all mutations affecting open reading frames (ORFs) in the 68-1 bacterial artificial chromosome (BAC). Inoculation of adult, immunocompetent, RhCMV-naïve RM with the reconstituted virus resulted in significant viremia in the blood similar to primary isolates of RhCMV and furthermore led to high viral genome copy numbers in many tissues at day 14 post infection. In contrast, viral dissemination was greatly reduced upon deletion of genes also lacking in 68-1. Transcriptome analysis of infected tissues further revealed that chemokine-like genes deleted in 68-1 are among the most highly expressed viral transcripts both in vitro and in vivo consistent with an important immunomodulatory function of the respective proteins. We conclude that FL-RhCMV displays in vitro and in vivo characteristics of a wildtype virus while being amenable to genetic modifications through BAC recombineering techniques.
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Affiliation(s)
- Husam Taher
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Eisa Mahyari
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Craig Kreklywich
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Luke S. Uebelhoer
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Matthew R. McArdle
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Matilda J. Moström
- Tulane National Primate Research Center, Tulane University, Covington, Louisiana, United States of America
| | - Amruta Bhusari
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Michael Nekorchuk
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Xiaofei E
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Travis Whitmer
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Elizabeth A. Scheef
- Tulane National Primate Research Center, Tulane University, Covington, Louisiana, United States of America
| | - Lesli M. Sprehe
- Tulane National Primate Research Center, Tulane University, Covington, Louisiana, United States of America
| | - Dawn L. Roberts
- Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Colette M. Hughes
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Kerianne A. Jackson
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Andrea N. Selseth
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Abigail B. Ventura
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Hillary C. Cleveland-Rubeor
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Yujuan Yue
- Center for Comparative Medicine and Department of Medical Pathology, University of California, Davis, California, United States of America
| | - Kimberli A. Schmidt
- Center for Comparative Medicine and Department of Medical Pathology, University of California, Davis, California, United States of America
| | - Jason Shao
- Statistical Center for HIV/AIDS Research and Prevention, Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Paul T. Edlefsen
- Statistical Center for HIV/AIDS Research and Prevention, Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Jeremy Smedley
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Timothy F. Kowalik
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Richard J. Stanton
- Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Michael K. Axthelm
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Jacob D. Estes
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Scott G. Hansen
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Amitinder Kaur
- Tulane National Primate Research Center, Tulane University, Covington, Louisiana, United States of America
| | - Peter A. Barry
- Center for Comparative Medicine and Department of Medical Pathology, University of California, Davis, California, United States of America
| | - Benjamin N. Bimber
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Louis J. Picker
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Daniel N. Streblow
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Klaus Früh
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Daniel Malouli
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
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14
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Wang YQ, Zhao XY. Human Cytomegalovirus Primary Infection and Reactivation: Insights From Virion-Carried Molecules. Front Microbiol 2020; 11:1511. [PMID: 32765441 PMCID: PMC7378892 DOI: 10.3389/fmicb.2020.01511] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 06/10/2020] [Indexed: 12/12/2022] Open
Abstract
Human cytomegalovirus (HCMV), a ubiquitous beta-herpesvirus, is able to establish lifelong latency after initial infection. Periodical reactivation occurs after immunosuppression, remaining a major cause of death in immunocompromised patients. HCMV has to reach a structural and functional balance with the host at its earliest entry. Virion-carried mediators are considered to play pivotal roles in viral adaptation into a new cellular environment upon entry. Additionally, one clear difference between primary infection and reactivation is the idea that virion-packaged factors are already formed such that those molecules can be used swiftly by the virus. In contrast, virion-carried mediators have to be transcribed and translated; thus, they are not readily available during reactivation. Hence, understanding virion-carried molecules helps to elucidate HCMV reactivation. In this article, the impact of virion-packaged molecules on viral structure, biological behavior, and viral life cycle will be reviewed.
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Affiliation(s)
- Yu-Qing Wang
- Peking University People's Hospital, Peking University Institute of Hematology, National Clinical Research Center for Hematologic Disease, Key Laboratory of Hematopoietic Stem Cell Transplantation, Beijing, China.,PKU-THU Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Xiang-Yu Zhao
- Peking University People's Hospital, Peking University Institute of Hematology, National Clinical Research Center for Hematologic Disease, Key Laboratory of Hematopoietic Stem Cell Transplantation, Beijing, China
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15
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Specialization for Cell-Free or Cell-to-Cell Spread of BAC-Cloned Human Cytomegalovirus Strains Is Determined by Factors beyond the UL128-131 and RL13 Loci. J Virol 2020; 94:JVI.00034-20. [PMID: 32321807 DOI: 10.1128/jvi.00034-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 04/13/2020] [Indexed: 12/17/2022] Open
Abstract
It is widely held that clinical isolates of human cytomegalovirus (HCMV) are highly cell associated, and mutations affecting the UL128-131 and RL13 loci that arise in culture lead to the appearance of a cell-free spread phenotype. The bacterial artificial chromosome (BAC) clone Merlin (ME) expresses abundant UL128-131, is RL13 impaired, and produces low infectivity virions in fibroblasts, whereas TB40/e (TB) and TR are low in UL128-131, are RL13 intact, and produce virions of much higher infectivity. Despite these differences, quantification of spread by flow cytometry revealed remarkably similar spread efficiencies in fibroblasts. In epithelial cells, ME spread more efficiently, consistent with robust UL128-131 expression. Strikingly, ME spread far better than did TB or TR in the presence of neutralizing antibodies on both cell types, indicating that ME is not simply deficient at cell-free spread but is particularly efficient at cell-to-cell spread, whereas TB and TR cell-to-cell spread is poor. Sonically disrupted ME-infected cells contained scant infectivity, suggesting that the efficient cell-to-cell spread mechanism of ME depends on features of the intact cells such as junctions or intracellular trafficking processes. Even when UL128-131 was transcriptionally repressed, cell-to-cell spread of ME was still more efficient than that of TB or TR. Moreover, RL13 expression comparably reduced both cell-free and cell-to-cell spread of all three strains, suggesting that it acts at a stage of assembly and/or egress common to both routes of spread. Thus, HCMV strains can be highly specialized for either for cell-free or cell-to-cell spread, and these phenotypes are determined by factors beyond the UL128-131 or RL13 loci.IMPORTANCE Both cell-free and cell-to-cell spread are likely important for the natural biology of HCMV. In culture, strains clearly differ in their capacity for cell-free spread as a result of differences in the quantity and infectivity of extracellular released progeny. However, it has been unclear whether "cell-associated" phenotypes are simply the result of poor cell-free spread or are indicative of particularly efficient cell-to-cell spread mechanisms. By measuring the kinetics of spread at early time points, we were able to show that HCMV strains can be highly specialized to either cell-free or cell-to-cell mechanisms, and this was not strictly linked the efficiency of cell-free spread. Our results provide a conceptual approach to evaluating intervention strategies for their ability to limit cell-free or cell-to-cell spread as independent processes.
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16
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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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17
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Characterization of pUL5, an HCMV protein interacting with the cellular protein IQGAP1. Virology 2019; 540:57-65. [PMID: 31739185 DOI: 10.1016/j.virol.2019.10.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 10/30/2019] [Accepted: 10/30/2019] [Indexed: 01/01/2023]
Abstract
Among the Herpesviridae, human cytomegalovirus (HCMV) owns the largest genome and displays a huge coding potential. Here, we characterized the UL5 gene product (pUL5) of the clinical isolate TR strain. The protein was predicted as a 166-amino-acid membrane protein with a theoretical mass of 19 kDa. Recombinant virus expressing pUL5 with a tag allowed the identification of two pUL5 non-glycosylated species of approximately 19 and 9 kDa, expressed with early and late kinetic respectively. Experiments in infection confirmed that the lower molecular weight species was translated from an internal ATG in the UL5 open reading frame. Confocal microscopy analysis showed that pUL5 localized within the assembly compartment, but is not incorporated in the virion, as shown by Western blot on purified viral particles. Finally, pull-down experiments coupled with mass spectrometry analysis identified IQGAP1 as a pUL5 interactor, giving new hints on possible roles of pUL5 during HCMV infection.
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18
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Berry R, Watson GM, Jonjic S, Degli-Esposti MA, Rossjohn J. Modulation of innate and adaptive immunity by cytomegaloviruses. Nat Rev Immunol 2019; 20:113-127. [PMID: 31666730 DOI: 10.1038/s41577-019-0225-5] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2019] [Indexed: 02/07/2023]
Abstract
The coordinated activities of innate and adaptive immunity are critical for effective protection against viruses. To counter this, some viruses have evolved sophisticated strategies to circumvent immune cell recognition. In particular, cytomegaloviruses encode large arsenals of molecules that seek to subvert T cell and natural killer cell function via a remarkable array of mechanisms. Consequently, these 'immunoevasins' play a fundamental role in shaping the nature of the immune system by driving the evolution of new immune receptors and recognition mechanisms. Here, we review the diverse strategies adopted by cytomegaloviruses to target immune pathways and outline the host's response.
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Affiliation(s)
- Richard Berry
- Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia. .,Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia. .,Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria, Australia.
| | - Gabrielle M Watson
- Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia.,Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia.,Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria, Australia
| | - Stipan Jonjic
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Mariapia A Degli-Esposti
- Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia.,Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia.,Centre for Experimental Immunology, Lions Eye Institute, Perth, Western Australia, Australia
| | - Jamie Rossjohn
- Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia.,Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia.,Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria, Australia.,Institute of Infection and Immunity, Cardiff University School of Medicine, Cardiff, UK
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19
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Jenks JA, Goodwin ML, Permar SR. The Roles of Host and Viral Antibody Fc Receptors in Herpes Simplex Virus (HSV) and Human Cytomegalovirus (HCMV) Infections and Immunity. Front Immunol 2019; 10:2110. [PMID: 31555298 PMCID: PMC6742691 DOI: 10.3389/fimmu.2019.02110] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 08/21/2019] [Indexed: 12/01/2022] Open
Abstract
Herpesvirus infections are a leading cause of neurodevelopmental delay in newborns and end-organ disease in immunocompromised patients. One leading strategy to reduce the disease burden of herpesvirus infections such as herpes simplex virus (HSV) and human cytomegalovirus (HCMV) is to prevent primary acquisition by vaccination, yet vaccine development remains hampered by limited understanding of immune correlates of protection against infection. Traditionally, vaccine development has aimed to increase antibody titers with neutralizing function, which involves the direct binding of antibodies to viral particles. However, recent research has explored the numerous other responses that can be mediated by engagement of the antibody constant region (Fc) with Fc receptors (FcR) present on immune cells or with complement molecules. These functions include antiviral responses such as antibody-dependent cell-mediated cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP). Uniquely, herpesviruses encode FcR that can act as distractor receptors for host antiviral IgG, thus enabling viral evasion of host defenses. This review focuses on the relative roles of neutralizing and non-neutralizing functions antibodies that target herpesvirus antigens for HSV and HCMV, as well as the roles of Fc-FcR interactions for both host defenses and viral escape.
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Affiliation(s)
- Jennifer A Jenks
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC, United States
| | - Matthew L Goodwin
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC, United States
| | - Sallie R Permar
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC, United States.,Department of Pediatrics, Children's Health and Discovery Institute, Durham, NC, United States
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20
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Suárez NM, Musonda KG, Escriva E, Njenga M, Agbueze A, Camiolo S, Davison AJ, Gompels UA. Multiple-Strain Infections of Human Cytomegalovirus With High Genomic Diversity Are Common in Breast Milk From Human Immunodeficiency Virus-Infected Women in Zambia. J Infect Dis 2019; 220:792-801. [PMID: 31050737 PMCID: PMC6667993 DOI: 10.1093/infdis/jiz209] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 05/01/2019] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND In developed countries, human cytomegalovirus (HCMV) is a major pathogen in congenitally infected and immunocompromised individuals, where multiple-strain infection appears linked to disease severity. The situation is less documented in developing countries. In Zambia, breast milk is a key route for transmitting HCMV and carries higher viral loads in human immunodeficiency virus (HIV)-infected women. We investigated HCMV strain diversity. METHODS High-throughput sequence datasets were generated from 28 HCMV-positive breast milk samples donated by 22 mothers (15 HIV-infected and 7 HIV-negative) at 4-16 weeks postpartum, then analyzed by genome assembly and novel motif-based genotyping in 12 hypervariable HCMV genes. RESULTS Among the 20 samples from 14 donors (13 HIV-infected and one HIV-negative) who yielded data meeting quality thresholds, 89 of the possible 109 genotypes were detected, and multiple-strain infections involving up to 5 strains per person were apparent in 9 HIV-infected women. Strain diversity was extensive among individuals but conserved compartmentally and longitudinally within them. Genotypic linkage was maintained within hypervariable UL73/UL74 and RL12/RL13/UL1 loci for virus entry and immunomodulation, but not between genes more distant from each other. CONCLUSIONS Breast milk from HIV-infected women contains multiple HCMV strains of high genotypic complexity and thus constitutes a major source for transmitting viral diversity.
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Affiliation(s)
- Nicolás M Suárez
- Medical Research Council–University of Glasgow Centre for Virus Research, United Kingdom
| | - Kunda G Musonda
- Pathogen Molecular Biology Department, London School of Hygiene and Tropical Medicine, United Kingdom
- Virology Laboratory, University Teaching Hospital, Lusaka, Zambia
| | - Eric Escriva
- Pathogen Molecular Biology Department, London School of Hygiene and Tropical Medicine, United Kingdom
- Birkbeck College, University of London, United Kingdom
| | - Margaret Njenga
- Pathogen Molecular Biology Department, London School of Hygiene and Tropical Medicine, United Kingdom
| | - Anthony Agbueze
- Pathogen Molecular Biology Department, London School of Hygiene and Tropical Medicine, United Kingdom
- Birkbeck College, University of London, United Kingdom
| | - Salvatore Camiolo
- Medical Research Council–University of Glasgow Centre for Virus Research, United Kingdom
| | - Andrew J Davison
- Medical Research Council–University of Glasgow Centre for Virus Research, United Kingdom
| | - Ursula A Gompels
- Pathogen Molecular Biology Department, London School of Hygiene and Tropical Medicine, United Kingdom
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21
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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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22
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Pathogen at the Gates: Human Cytomegalovirus Entry and Cell Tropism. Viruses 2018; 10:v10120704. [PMID: 30544948 PMCID: PMC6316194 DOI: 10.3390/v10120704] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 12/04/2018] [Accepted: 12/05/2018] [Indexed: 12/24/2022] Open
Abstract
The past few years have brought substantial progress toward understanding how human cytomegalovirus (HCMV) enters the remarkably wide spectrum of cell types and tissues that it infects. Neuropilin-2 and platelet-derived growth factor receptor alpha (PDGFRα) were identified as receptors, respectively, for the trimeric and pentameric glycoprotein H/glycoprotein L (gH/gL) complexes that in large part govern HCMV cell tropism, while CD90 and CD147 were also found to play roles during entry. X-ray crystal structures for the proximal viral fusogen, glycoprotein B (gB), and for the pentameric gH/gL complex (pentamer) have been solved. A novel virion gH complex consisting of gH bound to UL116 instead of gL was described, and findings supporting the existence of a stable complex between gH/gL and gB were reported. Additional work indicates that the pentamer promotes a mode of cell-associated spread that resists antibody neutralization, as opposed to the trimeric gH/gL complex (trimer), which appears to be broadly required for the infectivity of cell-free virions. Finally, viral factors such as UL148 and US16 were identified that can influence the incorporation of the alternative gH/gL complexes into virions. We will review these advances and their implications for understanding HCMV entry and cell tropism.
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23
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Abstract
Natural killer (NK) cells play an important role in the host response against viral infections and cancer development. They are able to kill virus-infected and tumor cells, and they produce different important cytokines that stimulate the antiviral and antitumor adaptive immune response, particularly interferon gamma. NK cells are of particular importance in herpesvirus infections, which is illustrated by systemic and life-threatening herpesvirus disease symptoms in patients with deficiencies in NK cell activity and by the myriad of reports describing herpesvirus NK cell evasion strategies. The latter is particularly obvious for cytomegaloviruses, but increasing evidence indicates that most, if not all, members of the herpesvirus family suppress NK cell activity to some extent. This review discusses the different NK cell evasion strategies described for herpesviruses and how this knowledge may translate to clinical applications.
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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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25
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A Prominent Role of the Human Cytomegalovirus UL8 Glycoprotein in Restraining Proinflammatory Cytokine Production by Myeloid Cells at Late Times during Infection. J Virol 2018; 92:JVI.02229-17. [PMID: 29467314 DOI: 10.1128/jvi.02229-17] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 02/14/2018] [Indexed: 01/21/2023] Open
Abstract
Human cytomegalovirus (HCMV) persistence in infected individuals relies on a plethora of mechanisms to efficiently reduce host immune responses. To that end, HCMV uses a variety of gene products, some of which have not been identified yet. Here we characterized the UL8 gene, which consists of two exons, sharing the first with the HCMV RL11 family member UL7 UL8 is a transmembrane protein with an N-terminal immunoglobulin (Ig)-like domain in common with UL7 but with an extended stalk and a distinctive cytoplasmic tail. The UL8 open reading frame gives rise to a heavily glycosylated protein predominantly expressed on the cell surface, from where it can be partially endocytosed and subsequently degraded. Infections with UL8-tagged viruses indicated that UL8 was synthesized with late-phase kinetics. By virtue of its highly conserved Ig-like domain, this viral protein interacted with a surface molecule present on activated neutrophils. Notably, when ectopically expressed in THP-1 myeloid cells, UL8 was able to significantly reduce the production of a variety of proinflammatory cytokines. Mutations in UL8 indicated that this functional effect was mediated by the cell surface expression of its Ig-like domain. To investigate the impact of the viral protein in the infection context, we engineered HCMVs lacking the UL8 gene and demonstrated that UL8 decreases the release of a large number of proinflammatory factors at late times after infection of THP-1 cells. Our data indicate that UL8 may exert an immunosuppressive role key for HCMV survival in the host.IMPORTANCE HCMV is a major pathogen that causes life-threatening diseases and disabilities in infected newborns and immunocompromised individuals. Containing one of the largest genomes among all reported human viruses, HCMV encodes an impressive repertoire of gene products. However, the functions of a large proportion of them still remain unknown, a fact that complicates the design of new therapeutic approaches to prevent or treat HCMV-associated diseases. In this report, we have conducted an extensive study of UL8, one of the previously uncharacterized HCMV open reading frames. We found that the UL8 protein is expressed at late times postinfection and utilized by HCMV to reduce the production of proinflammatory factors by infected myeloid cells. Thus, the work presented here points to a key role of UL8 as a novel HCMV immune modulator capable of restraining host antiviral defenses.
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26
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Cloning, Assembly, and Modification of the Primary Human Cytomegalovirus Isolate Toledo by Yeast-Based Transformation-Associated Recombination. mSphere 2017; 2:mSphere00331-17. [PMID: 28989973 PMCID: PMC5628293 DOI: 10.1128/mspheredirect.00331-17] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 07/29/2017] [Indexed: 01/17/2023] Open
Abstract
The genomes of large DNA viruses, such as human cytomegalovirus (HCMV), are difficult to manipulate using current genetic tools, and at this time, it is not possible to obtain, molecular clones of CMV without extensive tissue culture. To overcome these limitations, we used synthetic biology tools to capture genomic fragments from viral DNA and assemble full-length genomes in yeast. Using an early passage of the HCMV isolate Toledo containing a mixture of wild-type and tissue culture-adapted virus. we directly cloned the majority sequence and recreated the minority sequence by simultaneous modification of multiple genomic regions. Thus, our novel approach provides a paradigm to not only efficiently engineer HCMV and other large DNA viruses on a genome-wide scale but also facilitates the cloning and genetic manipulation of primary isolates and provides a pathway to generating entirely synthetic genomes. Genetic engineering of cytomegalovirus (CMV) currently relies on generating a bacterial artificial chromosome (BAC) by introducing a bacterial origin of replication into the viral genome using in vivo recombination in virally infected tissue culture cells. However, this process is inefficient, results in adaptive mutations, and involves deletion of viral genes to avoid oversized genomes when inserting the BAC cassette. Moreover, BAC technology does not permit the simultaneous manipulation of multiple genome loci and cannot be used to construct synthetic genomes. To overcome these limitations, we adapted synthetic biology tools to clone CMV genomes in Saccharomyces cerevisiae. Using an early passage of the human CMV isolate Toledo, we first applied transformation-associated recombination (TAR) to clone 16 overlapping fragments covering the entire Toledo genome in Saccharomyces cerevisiae. Then, we assembled these fragments by TAR in a stepwise process until the entire genome was reconstituted in yeast. Since next-generation sequence analysis revealed that the low-passage-number isolate represented a mixture of parental and fibroblast-adapted genomes, we selectively modified individual DNA fragments of fibroblast-adapted Toledo (Toledo-F) and again used TAR assembly to recreate parental Toledo (Toledo-P). Linear, full-length HCMV genomes were transfected into human fibroblasts to recover virus. Unlike Toledo-F, Toledo-P displayed characteristics of primary isolates, including broad cellular tropism in vitro and the ability to establish latency and reactivation in humanized mice. Our novel strategy thus enables de novo cloning of CMV genomes, more-efficient genome-wide engineering, and the generation of viral genomes that are partially or completely derived from synthetic DNA. IMPORTANCE The genomes of large DNA viruses, such as human cytomegalovirus (HCMV), are difficult to manipulate using current genetic tools, and at this time, it is not possible to obtain, molecular clones of CMV without extensive tissue culture. To overcome these limitations, we used synthetic biology tools to capture genomic fragments from viral DNA and assemble full-length genomes in yeast. Using an early passage of the HCMV isolate Toledo containing a mixture of wild-type and tissue culture-adapted virus. we directly cloned the majority sequence and recreated the minority sequence by simultaneous modification of multiple genomic regions. Thus, our novel approach provides a paradigm to not only efficiently engineer HCMV and other large DNA viruses on a genome-wide scale but also facilitates the cloning and genetic manipulation of primary isolates and provides a pathway to generating entirely synthetic genomes.
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27
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Farré D, Martínez-Vicente P, Engel P, Angulo A. Immunoglobulin superfamily members encoded by viruses and their multiple roles in immune evasion. Eur J Immunol 2017; 47:780-796. [PMID: 28383780 DOI: 10.1002/eji.201746984] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 03/11/2017] [Accepted: 03/29/2017] [Indexed: 12/31/2022]
Abstract
Pathogens have developed a plethora of strategies to undermine host immune defenses in order to guarantee their survival. For large DNA viruses, these immune evasion mechanisms frequently rely on the expression of genes acquired from host genomes. Horizontally transferred genes include members of the immunoglobulin superfamily, whose products constitute the most diverse group of proteins of vertebrate genomes. Their promiscuous immunoglobulin domains, which comprise the building blocks of these molecules, are involved in a large variety of functions mediated by ligand-binding interactions. The flexible structural nature of the immunoglobulin domains makes them appealing targets for viral capture due to their capacity to generate high functional diversity. Here, we present an up-to-date review of immunoglobulin superfamily gene homologs encoded by herpesviruses, poxviruses, and adenoviruses, that include CD200, CD47, Fc receptors, interleukin-1 receptor 2, interleukin-18 binding protein, CD80, carcinoembryonic antigen-related cell adhesion molecules, and signaling lymphocyte activation molecules. We discuss their distinct structural attributes, binding properties, and functions, shaped by evolutionary pressures to disarm specific immune pathways. We include several novel genes identified from extensive genome database surveys. An understanding of the properties and modes of action of these viral proteins may guide the development of novel immune-modulatory therapeutic tools.
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Affiliation(s)
- Domènec Farré
- Immunology Unit, Department of Biomedical Sciences, Medical School, University of Barcelona, Barcelona, Spain
| | - Pablo Martínez-Vicente
- Immunology Unit, Department of Biomedical Sciences, Medical School, University of Barcelona, Barcelona, Spain
| | - Pablo Engel
- Immunology Unit, Department of Biomedical Sciences, Medical School, University of Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain
| | - Ana Angulo
- Immunology Unit, Department of Biomedical Sciences, Medical School, University of Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain
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28
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Burwitz BJ, Malouli D, Bimber BN, Reed JS, Ventura AB, Hancock MH, Uebelhoer LS, Bhusari A, Hammond KB, Espinosa Trethewy RG, Klug A, Legasse AW, Axthelm MK, Nelson JA, Park BS, Streblow DN, Hansen SG, Picker LJ, Früh K, Sacha JB. Cross-Species Rhesus Cytomegalovirus Infection of Cynomolgus Macaques. PLoS Pathog 2016; 12:e1006014. [PMID: 27829026 PMCID: PMC5102353 DOI: 10.1371/journal.ppat.1006014] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 10/20/2016] [Indexed: 12/14/2022] Open
Abstract
Cytomegaloviruses (CMV) are highly species-specific due to millennia of co-evolution and adaptation to their host, with no successful experimental cross-species infection in primates reported to date. Accordingly, full genome phylogenetic analysis of multiple new CMV field isolates derived from two closely related nonhuman primate species, Indian-origin rhesus macaques (RM) and Mauritian-origin cynomolgus macaques (MCM), revealed distinct and tight lineage clustering according to the species of origin, with MCM CMV isolates mirroring the limited genetic diversity of their primate host that underwent a population bottleneck 400 years ago. Despite the ability of Rhesus CMV (RhCMV) laboratory strain 68-1 to replicate efficiently in MCM fibroblasts and potently inhibit antigen presentation to MCM T cells in vitro, RhCMV 68-1 failed to productively infect MCM in vivo, even in the absence of host CD8+ T and NK cells. In contrast, RhCMV clone 68-1.2, genetically repaired to express the homologues of the HCMV anti-apoptosis gene UL36 and epithelial cell tropism genes UL128 and UL130 absent in 68-1, efficiently infected MCM as evidenced by the induction of transgene-specific T cells and virus shedding. Recombinant variants of RhCMV 68-1 and 68-1.2 revealed that expression of either UL36 or UL128 together with UL130 enabled productive MCM infection, indicating that multiple layers of cross-species restriction operate even between closely related hosts. Cumulatively, these results implicate cell tropism and evasion of apoptosis as critical determinants of CMV transmission across primate species barriers, and extend the macaque model of human CMV infection and immunology to MCM, a nonhuman primate species with uniquely simplified host immunogenetics.
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Affiliation(s)
- Benjamin J. Burwitz
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Daniel Malouli
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Benjamin N. Bimber
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Jason S. Reed
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Abigail B. Ventura
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Meaghan H. Hancock
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Luke S. Uebelhoer
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Amruta Bhusari
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Katherine B. Hammond
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Renee G. Espinosa Trethewy
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Alex Klug
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Alfred W. Legasse
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Michael K. Axthelm
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Jay A. Nelson
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Byung S. Park
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Daniel N. Streblow
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Scott G. Hansen
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Louis J. Picker
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Klaus Früh
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Jonah B. Sacha
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
- * E-mail:
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29
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Pandey JP, Namboodiri AM, Mohan S, Nietert PJ, Peterson L. Genetic markers of immunoglobulin G and immunity to cytomegalovirus in patients with breast cancer. Cell Immunol 2016; 312:67-70. [PMID: 27825564 DOI: 10.1016/j.cellimm.2016.11.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 10/13/2016] [Accepted: 11/01/2016] [Indexed: 01/18/2023]
Abstract
Human cytomegalovirus (CMV), a ubiquitous herpesvirus, has been implicated in the etiology of breast cancer. It is clear that not all people exposed to CMV are equally likely to develop this malignancy, implying the presence of host genetic factors that might modulate the cancer-spurring properties of the virus. CMV has evolved sophisticated strategies for evading host immunosurveillance. One strategy involves encoding decoy Fcγ receptors (FcγR) that thwart the Fcγ-mediated effector functions, such as antibody-dependent cellular cytotoxicity. In this investigation, using an enzyme-linked immunosorbent assay (ELISA), we aimed to determine whether the decoy FcγR encoded by the CMV gene RL13 binds differentially to anti-CMV antibodies expressing different immunoglobulin GM (γ marker) allotypes, genetic markers of immunoglobulin G (IgG). Results of our ELISA binding studies showed that the absorbance values for the binding of the viral FcγR to the GM 17-expressing IgG antibodies were significantly higher than for the GM 3-expressing antibodies (0.60 vs. 0.36; p=0.0019). These findings provide mechanistic insights into the modulating role played by the genetic variants of IgG in the generation of immunity to CMV in patients with breast cancer.
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Affiliation(s)
- Janardan P Pandey
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, SC 29425, USA.
| | - Aryan M Namboodiri
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Sarumathi Mohan
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Paul J Nietert
- Department of Public Health Sciences, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Lindsay Peterson
- Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, USA
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30
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Bruno L, Cortese M, Monda G, Gentile M, Calò S, Schiavetti F, Zedda L, Cattaneo E, Piccioli D, Schaefer M, Notomista E, Maione D, Carfì A, Merola M, Uematsu Y. Human cytomegalovirus pUL10 interacts with leukocytes and impairs TCR-mediated T-cell activation. Immunol Cell Biol 2016; 94:849-860. [PMID: 27192938 DOI: 10.1038/icb.2016.49] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 05/11/2016] [Accepted: 05/11/2016] [Indexed: 01/27/2023]
Abstract
Human cytomegalovirus (HCMV) is known to exert suppressive effects on the host immune system through expression of various viral genes, thus directly and indirectly affecting antiviral immunity of the infected individuals. We report here that HCMV UL10 encodes a protein (pUL10) with immunosuppressive properties. UL10 has been classified as a member of the HCMV RL11 gene family. Although pUL10 is known to be dispensable for viral replication in cultured cells, its amino-acid sequence is well conserved among different HCMV isolates, suggesting that the protein has a crucial role in viral survival in the host environment. We show that pUL10 is cleaved from the cell surface of fibroblasts as well as epithelial cells and interacts with a cellular receptor ubiquitously expressed on the surface of human leukocytes, demonstrated by ex vivo cell-based assays and flow cytometric analyses on both lymphoid cell lines and primary blood cells. Furthermore, preincubation of peripheral blood mononuclear cells with purified pUL10 ectodomain results in significantly impaired proliferation and substantially reduced pro-inflammatory cytokine production, in particular in CD4+ T cells upon in vitro T-cell stimulation. The inhibitory effect of pUL10 is also observed on antigen receptor-mediated intracellular tyrosine phosphorylation in a T-cell line. Based on these observations, we suggest that pUL10 is a newly identified immunomodulatory protein encoded by HCMV. Further elucidation of interactions between pUL10 and the host immune system during HCMV may contribute to finding ways towards new therapies for HCMV infection.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Eugenio Notomista
- Department of Biology, University of Naples 'Federico II', Naples, Italy
| | | | | | - Marcello Merola
- Research, GSK Vaccines, Siena, Italy.,Department of Biology, University of Naples 'Federico II', Naples, Italy
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31
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The Human Cytomegalovirus UL116 Gene Encodes an Envelope Glycoprotein Forming a Complex with gH Independently from gL. J Virol 2016; 90:4926-38. [PMID: 26937030 DOI: 10.1128/jvi.02517-15] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 02/22/2016] [Indexed: 02/01/2023] Open
Abstract
UNLABELLED Human cytomegalovirus (HCMV) is a major cause of morbidity and mortality in transplant patients and is the leading viral cause of birth defects after congenital infection. HCMV infection relies on the recognition of cell-specific receptors by one of the viral envelope glycoprotein complexes. Either the gH/gL/gO or the gH/gL/UL128/UL130/UL131A (Pentamer) complex has been found to fulfill this role, accounting for HCMV entry into almost all cell types. We have studied the UL116 gene product, a putative open reading frame identified by in silico analysis and predicted to code for a secreted protein. Virus infection experiments in mammalian cells demonstrated that UL116 is expressed late in the HCMV replication cycle and is a heavily glycosylated protein that first localizes to the cellular site of virus assembly and then inserts into the virion envelope. Transient-transfection studies revealed that UL116 is efficiently transported to the plasma membrane when coexpressed with gH and that gL competes with UL116 for gH binding. Further evidence for gH/UL116 complex formation was obtained by coimmunoprecipitation experiments on both transfected and infected cells and biochemical characterization of the purified complex. In summary, our results show that the product of the UL116 gene is an HCMV envelope glycoprotein that forms a novel gH-based complex alternative to gH/gL. Remarkably, the gH/UL116 complex is the first herpesvirus gH-based gL-less complex. IMPORTANCE HCMV infection can cause severe disease in immunocompromised adults and infants infected in utero The dissection of the HCMV entry machinery is important to understand the mechanism of viral infection and to identify new vaccine antigens. The gH/gL/gO and gH/gL/UL128/UL130/UL131 (Pentamer) complexes play a key role in HCMV cell entry and tropism. Both complexes are formed by an invariant gH/gL scaffold on which the other subunits assemble. Here, we show that the UL116 gene product is expressed in infected cells and forms a heterodimer with gH. The gH/UL116 complex is carried on the infectious virions, although in smaller amounts than gH/gL complexes. No gH/UL116/gL ternary complex formed in transfected cells, suggesting that the gH/UL116 complex is independent from gL. This new gH-based gL-free complex represents a potential target for a protective HCMV vaccine and opens new perspectives on the comprehension of the HCMV cell entry mechanism and tropism.
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Bagdonaite I, Nordén R, Joshi HJ, King SL, Vakhrushev SY, Olofsson S, Wandall HH. Global Mapping of O-Glycosylation of Varicella Zoster Virus, Human Cytomegalovirus, and Epstein-Barr Virus. J Biol Chem 2016; 291:12014-28. [PMID: 27129252 DOI: 10.1074/jbc.m116.721746] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Indexed: 12/27/2022] Open
Abstract
Herpesviruses are among the most complex and widespread viruses, infection and propagation of which depend on envelope proteins. These proteins serve as mediators of cell entry as well as modulators of the immune response and are attractive vaccine targets. Although envelope proteins are known to carry glycans, little is known about the distribution, nature, and functions of these modifications. This is particularly true for O-glycans; thus we have recently developed a "bottom up" mass spectrometry-based technique for mapping O-glycosylation sites on herpes simplex virus type 1. We found wide distribution of O-glycans on herpes simplex virus type 1 glycoproteins and demonstrated that elongated O-glycans were essential for the propagation of the virus. Here, we applied our proteome-wide discovery platform for mapping O-glycosites on representative and clinically significant members of the herpesvirus family: varicella zoster virus, human cytomegalovirus, and Epstein-Barr virus. We identified a large number of O-glycosites distributed on most envelope proteins in all viruses and further demonstrated conserved patterns of O-glycans on distinct homologous proteins. Because glycosylation is highly dependent on the host cell, we tested varicella zoster virus-infected cell lysates and clinically isolated virus and found evidence of consistent O-glycosites. These results present a comprehensive view of herpesvirus O-glycosylation and point to the widespread occurrence of O-glycans in regions of envelope proteins important for virus entry, formation, and recognition by the host immune system. This knowledge enables dissection of specific functional roles of individual glycosites and, moreover, provides a framework for design of glycoprotein vaccines with representative glycosylation.
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Affiliation(s)
- Ieva Bagdonaite
- From the Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, 2200 Copenhagen, Denmark and
| | - Rickard Nordén
- the Department of Infectious Diseases, Institute of Biomedicine, University of Gothenburg, 413 45 Gothenburg, Sweden
| | - Hiren J Joshi
- From the Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, 2200 Copenhagen, Denmark and
| | - Sarah L King
- From the Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, 2200 Copenhagen, Denmark and
| | - Sergey Y Vakhrushev
- From the Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, 2200 Copenhagen, Denmark and
| | - Sigvard Olofsson
- the Department of Infectious Diseases, Institute of Biomedicine, University of Gothenburg, 413 45 Gothenburg, Sweden
| | - Hans H Wandall
- From the Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, 2200 Copenhagen, Denmark and
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Wang G, Ren G, Cui X, Lu Z, Ma Y, Qi Y, Huang Y, Liu Z, Sun Z, Ruan Q. Human cytomegalovirus RL13 protein interacts with host NUDT14 protein affecting viral DNA replication. Mol Med Rep 2016; 13:2167-74. [PMID: 26781650 DOI: 10.3892/mmr.2016.4778] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 12/18/2015] [Indexed: 11/05/2022] Open
Abstract
The interaction between the host and human cytomegalovirus (HCMV) is important in determining the outcome of a viral infection. The HCMV RL13 gene product exerts independent, inhibitory effects on viral growth in fibroblasts and epithelial cells. At present, there are few reports on the interactions between the HCMV RL13 protein and human host proteins. The present study provided direct evidence for the specific interaction between HCMV RL13 and host nucleoside diphosphate linked moiety X (nudix)‑type motif 14 (NUDT14), a UDP‑glucose pyrophosphatase, using two‑hybrid screening, an in vitro glutathione S‑transferase pull‑down assay, and co‑immunoprecipitation in human embryonic kidney HEK293 cells. Additionally, the RL13 protein was shown to co‑localize with the NUDT14 protein in the HEK293 cell membrane and cytoplasm, demonstrated using fluorescence confocal microscopy. Decreasing the expression level of NUDT14 via NUDT14‑specific small interfering RNAs increased the number of viral DNA copies in the HCMV‑infected cells. However, the overexpression of NUDT14 in a stably expressing cell line did not affect viral DNA levels significantly in the HCMV infected cells. Based on the known functions of NUDT14, the results of the present study suggested that the interaction between the RL13 protein and NUDT14 protein may be involved in HCMV DNA replication, and that NUDT14 may offer potential in the modulation of viral infection.
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Affiliation(s)
- Guili Wang
- Virus Laboratory, The Affiliated Shengjing Hospital, China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Gaowei Ren
- Virus Laboratory, The Affiliated Shengjing Hospital, China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Xin Cui
- Virus Laboratory, The Affiliated Shengjing Hospital, China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Zhitao Lu
- Virus Laboratory, The Affiliated Shengjing Hospital, China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Yanping Ma
- Virus Laboratory, The Affiliated Shengjing Hospital, China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Ying Qi
- Virus Laboratory, The Affiliated Shengjing Hospital, China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Yujing Huang
- Virus Laboratory, The Affiliated Shengjing Hospital, China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Zhongyang Liu
- Virus Laboratory, The Affiliated Shengjing Hospital, China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Zhengrong Sun
- Virus Laboratory, The Affiliated Shengjing Hospital, China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Qiang Ruan
- Virus Laboratory, The Affiliated Shengjing Hospital, China Medical University, Shenyang, Liaoning 110004, P.R. China
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Characterization of Antibody Bipolar Bridging Mediated by the Human Cytomegalovirus Fc Receptor gp68. J Virol 2016; 90:3262-7. [PMID: 26739053 DOI: 10.1128/jvi.02855-15] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 12/30/2015] [Indexed: 01/27/2023] Open
Abstract
The human cytomegalovirus glycoprotein gp68 functions as an Fc receptor for host IgGs and can form antibody bipolar bridging (ABB) complexes in which gp68 binds the Fc region of an antigen-bound IgG. Here we show that gp68-mediated endocytosis transports ABB complexes into endosomes, after which the complex is routed to lysosomes, presumably for degradation. These results suggest gp68 contributes to evasion of IgG-mediated immune responses by mediating destruction of host IgG and viral antigens.
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High-throughput analysis of human cytomegalovirus genome diversity highlights the widespread occurrence of gene-disrupting mutations and pervasive recombination. J Virol 2015; 89:7673-7695. [PMID: 25972543 DOI: 10.1128/jvi.00578-15] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Human cytomegalovirus is a widespread pathogen of major medical importance. It causes significant morbidity and mortality in the immunocompromised and congenital infections can result in severe disabilities or stillbirth. Development of a vaccine is prioritized, but no candidate is close to release. Although correlations of viral genetic variability with pathogenicity are suspected, knowledge about strain diversity of the 235kb genome is still limited. In this study, 96 full-length human cytomegalovirus genomes from clinical isolates were characterized, quadrupling the available information for full-genome analysis. These data provide the first high-resolution map of human cytomegalovirus interhost diversity and evolution. We show that cytomegalovirus is significantly more divergent than all other human herpesviruses and highlight hotspots of diversity in the genome. Importantly, 75% of strains are not genetically intact, but contain disruptive mutations in a diverse set of 26 genes, including immunomodulative genes UL40 and UL111A. These mutants are independent from culture passaging artifacts and circulate in natural populations. Pervasive recombination, which is linked to the widespread occurrence of multiple infections, was found throughout the genome. Recombination density was significantly higher than in other human herpesviruses and correlated with strain diversity. While the overall effects of strong purifying selection on virus evolution are apparent, evidence of diversifying selection was found in several genes encoding proteins that interact with the host immune system, including UL18, UL40, UL142 and UL147. These residues may present phylogenetic signatures of past and ongoing virus-host interactions. IMPORTANCE Human cytomegalovirus has the largest genome of all viruses that infect humans. Currently, there is a great interest in establishing associations between genetic variants and strain pathogenicity of this herpesvirus. Since the number of publicly available full-genome sequences is limited, knowledge about strain diversity is highly fragmented and biased towards a small set of loci. Combined with our previous work, we have now contributed 101 complete genome sequences. We have used these data to conduct the first high-resolution analysis of interhost genome diversity, providing an unbiased and comprehensive overview of cytomegalovirus variability. These data are of major value to the development of novel antivirals and a vaccine and to identify potential targets for genotype-phenotype experiments. Furthermore, they have enabled a thorough study of the evolutionary processes that have shaped cytomegalovirus diversity.
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Gabaev I, Elbasani E, Ameres S, Steinbrück L, Stanton R, Döring M, Lenac Rovis T, Kalinke U, Jonjic S, Moosmann A, Messerle M. Expression of the human cytomegalovirus UL11 glycoprotein in viral infection and evaluation of its effect on virus-specific CD8 T cells. J Virol 2014; 88:14326-39. [PMID: 25275132 PMCID: PMC4249143 DOI: 10.1128/jvi.01691-14] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 09/25/2014] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The human cytomegalovirus (CMV) UL11 open reading frame (ORF) encodes a putative type I transmembrane glycoprotein which displays remarkable amino acid sequence variability among different CMV isolates, suggesting that it represents an important virulence factor. In a previous study, we have shown that UL11 can interact with the cellular receptor tyrosine phosphatase CD45, which has a central role for signal transduction in T cells, and treatment of T cells with large amounts of a soluble UL11 protein inhibited their proliferation. In order to analyze UL11 expression in CMV-infected cells, we constructed CMV recombinants whose genomes either encode tagged UL11 versions or carry a stop mutation in the UL11 ORF. Moreover, we examined whether UL11 affects the function of virus-specific cytotoxic T lymphocytes (CTLs). We found that the UL11 ORF gives rise to several proteins due to both posttranslational modification and alternative translation initiation sites. Biotin labeling of surface proteins on infected cells indicated that only highly glycosylated UL11 forms are present at the plasma membrane, whereas less glycosylated UL11 forms were found in the endoplasmic reticulum. We did not find evidence of UL11 cleavage or secretion of a soluble UL11 version. Cocultivation of CTLs recognizing different CMV epitopes with fibroblasts infected with a UL11 deletion mutant or the parental strain revealed that under the conditions applied UL11 did not influence the activation of CMV-specific CD8 T cells. For further studies, we propose to investigate the interaction of UL11 with CD45 and the functional consequences in other immune cells expressing CD45. IMPORTANCE Human cytomegalovirus (CMV) belongs to those viruses that extensively interfere with the host immune response, yet the precise function of many putative immunomodulatory CMV proteins remains elusive. Previously, we have shown that the CMV UL11 protein interacts with the leukocyte common antigen CD45, a cellular receptor tyrosine phosphatase with a central role for signal transduction in T cells. Here, we examined the proteins expressed by the UL11 gene in CMV-infected cells and found that at least one form of UL11 is present at the cell surface, enabling it to interact with CD45 on immune cells. Surprisingly, CMV-expressed UL11 did not affect the activity of virus-specific CD8 T cells. This finding warrants investigation of the impact of UL11 on CD45 functions in other leukocyte subpopulations.
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Affiliation(s)
- Ildar Gabaev
- Department of Virology, Hannover Medical School, Hannover, Germany
| | - Endrit Elbasani
- Department of Virology, Hannover Medical School, Hannover, Germany
| | - Stefanie Ameres
- Clinical Cooperation Group Immunooncology, Helmholtz Centre Munich, Munich, Germany
| | - Lars Steinbrück
- Department of Virology, Hannover Medical School, Hannover, Germany
| | - Richard Stanton
- Institute of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Marius Döring
- Centre for Experimental and Clinical Infection Research, Twincore, Hannover, Germany
| | - Tihana Lenac Rovis
- Department of Histology and Embryology and Center for Proteomics, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Ulrich Kalinke
- Centre for Experimental and Clinical Infection Research, Twincore, Hannover, Germany
| | - Stipan Jonjic
- Department of Histology and Embryology and Center for Proteomics, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Andreas Moosmann
- Clinical Cooperation Group Immunooncology, Helmholtz Centre Munich, Munich, Germany German Center for Infection Research (DZIF), partner sites, Hannover and Munich, Germany
| | - Martin Messerle
- Department of Virology, Hannover Medical School, Hannover, Germany German Center for Infection Research (DZIF), partner sites, Hannover and Munich, Germany
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Corrales-Aguilar E, Hoffmann K, Hengel H. CMV-encoded Fcγ receptors: modulators at the interface of innate and adaptive immunity. Semin Immunopathol 2014; 36:627-40. [PMID: 25288477 DOI: 10.1007/s00281-014-0448-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2014] [Accepted: 09/03/2014] [Indexed: 12/22/2022]
Abstract
The constant region of IgG antibodies mediates antiviral activities upon engaging host Fcγ receptors (FcγRs) expressed by a variety of immune cells, such as antibody-dependent cellullar cytotoxcity (ADCC) executed by natural killer (NK)cells. Human cytomegalovirus (HCMV) is unique among viruses by encoding also an array of several Fcγ-binding glycoproteins with cell surface disposition and concomitant incorporation into the virion. Evidence is increasing that the virus-encoded Fcγ receptors differ in their Fcγ binding mode but effectively operate as adversaries of host FcγRs since they are able to prevent IgG-mediated triggering of activating host FcγRs, i.e., FcγRI, FcγRIIA, and FcγRIIIA. Here we discuss virus-encoded FcγRs as the first known HCMV inhibitors of IgG-mediated immunity which could account for the limited efficacy of HCMV hyperimmune globulin in clinical settings. A better understanding of their molecular mode of action opens up new perspectives for improving IgG therapies against HCMV disease.
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Affiliation(s)
- Eugenia Corrales-Aguilar
- Virology-CIET, Faculty of Microbiology, University of Costa Rica, 11501-2060, San José, Costa Rica
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Pandey JP. Immunoglobulin GM Genes, Cytomegalovirus Immunoevasion, and the Risk of Glioma, Neuroblastoma, and Breast Cancer. Front Oncol 2014; 4:236. [PMID: 25221749 PMCID: PMC4148617 DOI: 10.3389/fonc.2014.00236] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 08/16/2014] [Indexed: 12/16/2022] Open
Abstract
Human cytomegalovirus (HCMV), a common herpes virus, has been reported to be a risk factor for many diseases, including malignant diseases such as glioma, neuroblastoma, and breast cancer. Some of the HCMV-associated diseases (e.g., glioma) are rare. The question arises: how could a common virus be associated with uncommon diseases? Interactions between a major gene complex of the human immune system and a viral immunoevasion strategy – a probable mechanism of their co-evolutionary adaptation – may shed light on this paradox. To ensure its survival, HCMV has evolved sophisticated immunoevasion strategies. One strategy involves encoding decoy Fcγ receptors (FcγR), which may enable the virus to evade host immunosurveillance by avoiding the Fcγ-mediated effector consequences of anti-HCMV IgG antibody binding. Immunoglobulin G1 proteins expressing GM (γ marker) alleles 3 and 17 have differential affinity to the HCMV TRL11/IRL11-encoded FcγR, and thus act as effect modifiers of HCMV-associated malignancies. The high affinity GM 3 allele has been shown to be a risk factor for neuroblastoma, glioma, and breast cancer. Additional studies involving other viral FcγRs as well as GM alleles expressed on other IgG subclasses are warranted.
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Affiliation(s)
- Janardan P Pandey
- Department of Microbiology and Immunology, Medical University of South Carolina , Charleston, SC , USA
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Weekes MP, Tomasec P, Huttlin EL, Fielding CA, Nusinow D, Stanton RJ, Wang ECY, Aicheler R, Murrell I, Wilkinson GWG, Lehner PJ, Gygi SP. Quantitative temporal viromics: an approach to investigate host-pathogen interaction. Cell 2014; 157:1460-1472. [PMID: 24906157 PMCID: PMC4048463 DOI: 10.1016/j.cell.2014.04.028] [Citation(s) in RCA: 316] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 02/18/2014] [Accepted: 04/03/2014] [Indexed: 12/11/2022]
Abstract
A systematic quantitative analysis of temporal changes in host and viral proteins throughout the course of a productive infection could provide dynamic insights into virus-host interaction. We developed a proteomic technique called “quantitative temporal viromics” (QTV), which employs multiplexed tandem-mass-tag-based mass spectrometry. Human cytomegalovirus (HCMV) is not only an important pathogen but a paradigm of viral immune evasion. QTV detailed how HCMV orchestrates the expression of >8,000 cellular proteins, including 1,200 cell-surface proteins to manipulate signaling pathways and counterintrinsic, innate, and adaptive immune defenses. QTV predicted natural killer and T cell ligands, as well as 29 viral proteins present at the cell surface, potential therapeutic targets. Temporal profiles of >80% of HCMV canonical genes and 14 noncanonical HCMV open reading frames were defined. QTV is a powerful method that can yield important insights into viral infection and is applicable to any virus with a robust in vitro model. PaperClip
>8,000 proteins quantified over eight time points, including 1,200 cell-surface proteins Temporal profiles of 139/171 canonical HCMV proteins and 14 noncanonical HCMV ORFs Multiple families of cell-surface receptors selectively modulated by HCMV Multiple signaling pathways modulated during HCMV infection
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Affiliation(s)
- Michael P Weekes
- Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA; Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK.
| | - Peter Tomasec
- School of Medicine, Cardiff University, Tenovus Building, Heath Park, Cardiff CF14 4XX, UK
| | - Edward L Huttlin
- Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
| | - Ceri A Fielding
- School of Medicine, Cardiff University, Tenovus Building, Heath Park, Cardiff CF14 4XX, UK
| | - David Nusinow
- Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
| | - Richard J Stanton
- School of Medicine, Cardiff University, Tenovus Building, Heath Park, Cardiff CF14 4XX, UK
| | - Eddie C Y Wang
- School of Medicine, Cardiff University, Tenovus Building, Heath Park, Cardiff CF14 4XX, UK
| | - Rebecca Aicheler
- School of Medicine, Cardiff University, Tenovus Building, Heath Park, Cardiff CF14 4XX, UK
| | - Isa Murrell
- School of Medicine, Cardiff University, Tenovus Building, Heath Park, Cardiff CF14 4XX, UK
| | - Gavin W G Wilkinson
- School of Medicine, Cardiff University, Tenovus Building, Heath Park, Cardiff CF14 4XX, UK
| | - Paul J Lehner
- Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Steven P Gygi
- Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA.
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Van Damme E, Van Loock M. Functional annotation of human cytomegalovirus gene products: an update. Front Microbiol 2014; 5:218. [PMID: 24904534 PMCID: PMC4032930 DOI: 10.3389/fmicb.2014.00218] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 04/25/2014] [Indexed: 01/31/2023] Open
Abstract
Human cytomegalovirus is an opportunistic double-stranded DNA virus with one of the largest viral genomes known. The 235 kB genome is divided in a unique long (UL) and a unique short (US) region which are flanked by terminal and internal repeats. The expression of HCMV genes is highly complex and involves the production of protein coding transcripts, polyadenylated long non-coding RNAs, polyadenylated anti-sense transcripts and a variety of non-polyadenylated RNAs such as microRNAs. Although the function of many of these transcripts is unknown, they are suggested to play a direct or regulatory role in the delicately orchestrated processes that ensure HCMV replication and life-long persistence. This review focuses on annotating the complete viral genome based on three sources of information. First, previous reviews were used as a template for the functional keywords to ensure continuity; second, the Uniprot database was used to further enrich the functional database; and finally, the literature was manually curated for novel functions of HCMV gene products. Novel discoveries were discussed in light of the viral life cycle. This functional annotation highlights still poorly understood regions of the genome but more importantly it can give insight in functional clusters and/or may be helpful in the analysis of future transcriptomics and proteomics studies.
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Affiliation(s)
- Ellen Van Damme
- Janssen Infectious Diseases BVBA, Therapeutic Area of Infectious Diseases Beerse, Belgium
| | - Marnix Van Loock
- Janssen Infectious Diseases BVBA, Therapeutic Area of Infectious Diseases Beerse, Belgium
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Corrales-Aguilar E, Trilling M, Hunold K, Fiedler M, Le VTK, Reinhard H, Ehrhardt K, Mercé-Maldonado E, Aliyev E, Zimmermann A, Johnson DC, Hengel H. Human cytomegalovirus Fcγ binding proteins gp34 and gp68 antagonize Fcγ receptors I, II and III. PLoS Pathog 2014; 10:e1004131. [PMID: 24830376 PMCID: PMC4022731 DOI: 10.1371/journal.ppat.1004131] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 04/03/2014] [Indexed: 12/22/2022] Open
Abstract
Human cytomegalovirus (HCMV) establishes lifelong infection with recurrent episodes of virus production and shedding despite the presence of adaptive immunological memory responses including HCMV immune immunoglobulin G (IgG). Very little is known how HCMV evades from humoral and cellular IgG-dependent immune responses, the latter being executed by cells expressing surface receptors for the Fc domain of IgG (FcγRs). Remarkably, HCMV expresses the RL11-encoded gp34 and UL119-118-encoded gp68 type I transmembrane glycoproteins which bind Fcγ with nanomolar affinity. Using a newly developed FcγR activation assay, we tested if the HCMV-encoded Fcγ binding proteins (HCMV FcγRs) interfere with individual host FcγRs. In absence of gp34 or/and gp68, HCMV elicited a much stronger activation of FcγRIIIA/CD16, FcγRIIA/CD32A and FcγRI/CD64 by polyclonal HCMV-immune IgG as compared to wildtype HCMV. gp34 and gp68 co-expression culminates in the late phase of HCMV replication coinciding with the emergence of surface HCMV antigens triggering FcγRIII/CD16 responses by polyclonal HCMV-immune IgG. The gp34- and gp68-dependent inhibition of HCMV immune IgG was fully reproduced when testing the activation of primary human NK cells. Their broad antagonistic function towards FcγRIIIA, FcγRIIA and FcγRI activation was also recapitulated in a gain-of-function approach based on humanized monoclonal antibodies (trastuzumab, rituximab) and isotypes of different IgG subclasses. Surface immune-precipitation showed that both HCMV-encoded Fcγ binding proteins have the capacity to bind trastuzumab antibody-HER2 antigen complexes demonstrating simultaneous linkage of immune IgG with antigen and the HCMV inhibitors on the plasma membrane. Our studies reveal a novel strategy by which viral FcγRs can compete for immune complexes against various Fc receptors on immune cells, dampening their activation and antiviral immunity. Herpes viruses persist lifelong continuously alternating between latency and virus production and transmission. The latter events occur despite the presence of immune IgG antibodies. IgG acts by neutralization of virions and activation of immune cells bearing one or more surface receptors, called FcγRs, recognizing the constant Fc domain of IgG. Activating FcγRs induce a wide range of immune responses, including antibody dependent cellular cytotoxicity (ADCC) of virus-infected cells by natural killer (NK) cells, cytokine secretion and the uptake of immune complexes to enhance antigen presentation to T cells. We demonstrate that the HCMV glycoproteins RL11/gp34 and UL119-118/gp68 block IgG-mediated activation of FcγRs. A novel reporter cell-based assay was used to test FcγRs individually and assess their relative susceptibility to each antagonist. This approach revealed that gp34 and gp68 block triggering of activating FcγRs, i.e. FcγRI (CD64), FcγRII (CD32A) and FcγRIII (CD16). Co-immunoprecipitation showed the formation of ternary complexes containing IgG, IgG-bound antigen and the viral antagonists on the cell surface. Assigning the redundant abilities of HCMV to hinder IgG effector responses to the viral Fc binding proteins, we discuss gp34 and gp68 as potential culprits which might contribute to the limited efficacy of therapeutic IgG against HCMV.
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Affiliation(s)
| | - Mirko Trilling
- Institute for Virology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Katja Hunold
- Institute of Virology, University Medical Center, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Manuela Fiedler
- Institute for Virology, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Vu Thuy Khanh Le
- Institute for Virology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Henrike Reinhard
- Institute for Virology, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Katrin Ehrhardt
- Institute of Virology, University Medical Center, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Eva Mercé-Maldonado
- Institute for Virology, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Enver Aliyev
- Institute for Virology, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Albert Zimmermann
- Institute for Virology, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - David C. Johnson
- Department of Molecular Microbiology & Immunology, Oregon Health Sciences University, Portland, Oregon, United States of America
| | - Hartmut Hengel
- Institute of Virology, University Medical Center, Albert-Ludwigs-University Freiburg, Freiburg, Germany
- * E-mail:
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42
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Hu C, Chen J, Ye L, Chen R, Zhang L, Xue X. Codon usage bias in human cytomegalovirus and its biological implication. Gene 2014; 545:5-14. [PMID: 24814188 DOI: 10.1016/j.gene.2014.05.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2013] [Revised: 05/02/2014] [Accepted: 05/06/2014] [Indexed: 10/25/2022]
Abstract
Human cytomegalovirus (HCMV) infection, a worldwide contagion, causes a serious disorder in infected individuals. Analysis of codon usage can reveal much molecular information about this virus. The effective number of codon (ENC) values, relative synonymous codon usage (RSCU) values, codon adaptation index (CAI), and nucleotide contents was investigated in approximately 160 coding sequences (CDS) among 17 human cytomegalovirus genomes using the software CodonW. Linear regression analysis and logistic regression were performed to explore the preliminary data. The results showed that, overall, HCMV genomes had low codon usage bias (mean ENC=47.619). However, the ENC of individual CDS varied widely and was distributed unevenly between host-related genes and viral-self-function genes (P=0.002, odds ratio (OR)=3.194), as did the GC content (P=0.016, OR=2.178). The ENC values correlated with CAI, GC content, and the nucleotide composing at the 3rd codon position (GC3s) (P<0.001). There was a significant variation in the codon preference that depended on the RSCU data. The predicted ENC curve suggested that mutational pressure, rather than natural selection, was one of the main factors that determined the codon usage bias in HCMV. Among 123 genes with known function, the genes related to viral self-replication and viral-host interaction showed different ENC and CAI values, and GC and GC3s contents. In conclusion, the detailed codon usage bias theoretically revealed information concerning HCMV evolution and could be a valuable additional parameter for HCMV gene function research.
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Affiliation(s)
- Changyuan Hu
- Department of General Surgery, The First Affiliated Hospital of Wenzhou Medical University, Ouhai District 325035, Wenzhou City, Zhejiang Province, China
| | - Jing Chen
- Department of Rheumatism and Immunology, The First Affiliated Hospital of Wenzhou Medical University, Ouhai District 325035, Wenzhou City, Zhejiang Province, China
| | - Lulu Ye
- Department of Microbiology and Immunology, Institute of Molecular Virology and Immunology, Wenzhou Medical University, Ouhai District 325035, Wenzhou City, Zhejiang Province, China
| | - Renpin Chen
- Department of Gastroenterology and Hepatology, The First Affiliated Hospital of Wenzhou Medical University, Ouhai District 325035, Wenzhou City, Zhejiang Province, China
| | - Lifang Zhang
- Department of Microbiology and Immunology, Institute of Molecular Virology and Immunology, Wenzhou Medical University, Ouhai District 325035, Wenzhou City, Zhejiang Province, China
| | - Xiangyang Xue
- Department of Microbiology and Immunology, Institute of Molecular Virology and Immunology, Wenzhou Medical University, Ouhai District 325035, Wenzhou City, Zhejiang Province, China.
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Sijmons S, Van Ranst M, Maes P. Genomic and functional characteristics of human cytomegalovirus revealed by next-generation sequencing. Viruses 2014; 6:1049-72. [PMID: 24603756 PMCID: PMC3970138 DOI: 10.3390/v6031049] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 02/11/2014] [Accepted: 02/11/2014] [Indexed: 01/08/2023] Open
Abstract
The complete genome of human cytomegalovirus (HCMV) was elucidated almost 25 years ago using a traditional cloning and Sanger sequencing approach. Analysis of the genetic content of additional laboratory and clinical isolates has lead to a better, albeit still incomplete, definition of the coding potential and diversity of wild-type HCMV strains. The introduction of a new generation of massively parallel sequencing technologies, collectively called next-generation sequencing, has profoundly increased the throughput and resolution of the genomics field. These increased possibilities are already leading to a better understanding of the circulating diversity of HCMV clinical isolates. The higher resolution of next-generation sequencing provides new opportunities in the study of intrahost viral population structures. Furthermore, deep sequencing enables novel diagnostic applications for sensitive drug resistance mutation detection. RNA-seq applications have changed the picture of the HCMV transcriptome, which resulted in proof of a vast amount of splicing events and alternative transcripts. This review discusses the application of next-generation sequencing technologies, which has provided a clearer picture of the intricate nature of the HCMV genome. The continuing development and application of novel sequencing technologies will further augment our understanding of this ubiquitous, but elusive, herpesvirus.
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Affiliation(s)
- Steven Sijmons
- Laboratory of Clinical Virology, Rega Institute for Medical Research, K.U.Leuven, Minderbroedersstraat 10, Leuven BE-3000, Belgium.
| | - Marc Van Ranst
- Laboratory of Clinical Virology, Rega Institute for Medical Research, K.U.Leuven, Minderbroedersstraat 10, Leuven BE-3000, Belgium.
| | - Piet Maes
- Laboratory of Clinical Virology, Rega Institute for Medical Research, K.U.Leuven, Minderbroedersstraat 10, Leuven BE-3000, Belgium.
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