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Lin KM, Nightingale K, Soday L, Antrobus R, Weekes MP. Rapid Degradation Pathways of Host Proteins During HCMV Infection Revealed by Quantitative Proteomics. Front Cell Infect Microbiol 2021; 10:578259. [PMID: 33585265 PMCID: PMC7873559 DOI: 10.3389/fcimb.2020.578259] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 12/08/2020] [Indexed: 12/30/2022] Open
Abstract
Human cytomegalovirus (HCMV) is an important pathogen in immunocompromised individuals and neonates, and a paradigm for viral immune evasion. We previously developed a quantitative proteomic approach that identified 133 proteins degraded during the early phase of HCMV infection, including known and novel antiviral factors. The majority were rescued from degradation by MG132, which is known to inhibit lysosomal cathepsins in addition to the proteasome. Global definition of the precise mechanisms of host protein degradation is important both to improve our understanding of viral biology, and to inform novel antiviral therapeutic strategies. We therefore developed and optimized a multiplexed comparative proteomic analysis using the selective proteasome inhibitor bortezomib in addition to MG132, to provide a global mechanistic view of protein degradation. Of proteins rescued from degradation by MG132, 34-47 proteins were also rescued by bortezomib, suggesting both that the predominant mechanism of protein degradation employed by HCMV is via the proteasome, and that alternative pathways for degradation are nevertheless important. Our approach and data will enable improved mechanistic understanding of HCMV and other viruses, and provide a shortlist of candidate restriction factors for further analysis.
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Affiliation(s)
| | | | | | | | - Michael P. Weekes
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
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52
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Rand U, Kubsch T, Kasmapour B, Cicin-Sain L. A Novel Triple-Fluorescent HCMV Strain Reveals Gene Expression Dynamics and Anti-Herpesviral Drug Mechanisms. Front Cell Infect Microbiol 2021; 10:536150. [PMID: 33489928 PMCID: PMC7820782 DOI: 10.3389/fcimb.2020.536150] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 11/25/2020] [Indexed: 11/15/2022] Open
Abstract
Human Cytomegalovirus (HCMV) infection may result in severe outcomes in immunocompromised individuals such as AIDS patients, transplant recipients, and neonates. To date, no vaccines are available and there are only few drugs for anti-HCMV therapy. Adverse effects and the continuous emergence of drug-resistance strains require the identification of new drug candidates in the near future. Identification and characterization of such compounds and biological factors requires sensitive and reliable detection techniques of HCMV infection, gene expression and spread. In this work, we present and validate a novel concept for multi-reporter herpesviruses, identified through iterative testing of minimally invasive mutations. We integrated up to three fluorescence reporter genes into replication-competent HCMV strains, generating reporter HCMVs that allow the visualization of replication cycle stages of HCMV, namely the immediate early (IE), early (E), and late (L) phase. Fluorescent proteins with clearly distinguishable emission spectra were linked by 2A peptides to essential viral genes, allowing bicistronic expression of the viral and the fluorescent protein without major effects on viral fitness. By using this triple color reporter HCMV, we monitored gene expression dynamics of the IE, E, and L genes by measuring the fluorescent signal of the viral gene-associated fluorophores within infected cell populations and at high temporal resolution. We demonstrate distinct inhibitory profiles of foscarnet, fomivirsen, phosphonoacetic acid, ganciclovir, and letermovir reflecting their mode-of-action. In conclusion, our data argues that this experimental approach allows the identification and characterization of new drug candidates in a single step.
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Affiliation(s)
- Ulfert Rand
- Department of Vaccinology and Applied Microbiology, Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany
| | - Tobias Kubsch
- Department of Vaccinology and Applied Microbiology, Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany
| | - Bahram Kasmapour
- Department of Vaccinology and Applied Microbiology, Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany.,German Centre for Infection Research (DZIF), Hannover-Braunschweig Site, Braunschweig, Germany
| | - Luka Cicin-Sain
- Department of Vaccinology and Applied Microbiology, Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany.,German Centre for Infection Research (DZIF), Hannover-Braunschweig Site, Braunschweig, Germany.,Centre for Individualised Infection Medicine (CIIM), A Joint Venture of Helmholtz Centre for Infection Research (HZI) and Hannover Medical School (MHH), Braunschweig, Germany.,Cluster of Excellence RESIST (EXC 2155), Hannover Medical School (MHH), Hannover, Germany
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Griffiths P, Reeves M. Pathogenesis of human cytomegalovirus in the immunocompromised host. Nat Rev Microbiol 2021; 19:759-773. [PMID: 34168328 PMCID: PMC8223196 DOI: 10.1038/s41579-021-00582-z] [Citation(s) in RCA: 225] [Impact Index Per Article: 75.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/18/2021] [Indexed: 12/16/2022]
Abstract
Human cytomegalovirus (HCMV) is a herpesvirus that infects ~60% of adults in developed countries and more than 90% in developing countries. Usually, it is controlled by a vigorous immune response so that infections are asymptomatic or symptoms are mild. However, if the immune system is compromised, HCMV can replicate to high levels and cause serious end organ disease. Substantial progress is being made in understanding the natural history and pathogenesis of HCMV infection and disease in the immunocompromised host. Serial measures of viral load defined the dynamics of HCMV replication and are now used routinely to allow intervention with antiviral drugs in individual patients. They are also used as pharmacodynamic read-outs to evaluate prototype vaccines that may protect against HCMV replication and to define immune correlates of this protection. This novel information is informing the design of randomized controlled trials of new antiviral drugs and vaccines currently under evaluation. In this Review, we discuss immune responses to HCMV and countermeasures deployed by the virus, the establishment of latency and reactivation from it, exogenous reinfection with additional strains, pathogenesis, development of end organ disease, indirect effects of infection, immune correlates of control of replication, current treatment strategies and the evaluation of novel vaccine candidates.
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Affiliation(s)
- Paul Griffiths
- Institute for Immunity and Transplantation, University College London, London, UK.
| | - Matthew Reeves
- grid.83440.3b0000000121901201Institute for Immunity and Transplantation, University College London, London, UK
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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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55
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Investigational Antiviral Therapy Models for the Prevention and Treatment of Congenital Cytomegalovirus Infection during Pregnancy. Antimicrob Agents Chemother 2020; 65:AAC.01627-20. [PMID: 33077661 DOI: 10.1128/aac.01627-20] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/14/2020] [Indexed: 12/29/2022] Open
Abstract
Congenital cytomegalovirus (HCMV) infection may cause significant fetal malformation, lifelong disease, and, in severe cases, fetal or neonatal death. Placental infection with HCMV is the major mechanism of mother-to-child transmission (MTCT) and fetal injury. Thus, any pharmaceutical antiviral interference to reduce viral load may reduce placental damage, MTCT, and fetal disease. However, there is currently no licensed HCMV antiviral for use during pregnancy. In this study, aciclovir and the HCMV-specific antivirals letermovir, maribavir, and cidofovir were compared with ganciclovir for antiviral effects in model systems of pregnancy, including first-trimester TEV-1 trophoblast cell cultures and third-trimester ex vivo placental explant histocultures. HCMV-infected trophoblasts at 7 days postinfection (dpi) showed an EC50 of 21 μM for aciclovir, 0.0007 μM for letermovir, 0.11 μM for maribavir, and 0.29 μM for cidofovir, relative to 0.42 μM for ganciclovir. Antivirals added at 10 μM showed no cytotoxic effects and did not affect trophoblast cell proliferation (P > 0.9999). Multiple-round HCMV replication measured at 7 dpi showed letermovir, maribavir, and cidofovir treatment inhibited immediate early, early, and true late viral protein expression as assayed on Western blots. Antiviral treatment of HCMV-infected placental explants showed significant inhibition (P < 0.05) of viral replication with letermovir (83.3%), maribavir (83.6%), cidofovir (89.3%), and ganciclovir (82.4%), but not aciclovir (P > 0.9999). In ex vivo model systems, recently trialed HCMV antivirals letermovir and maribavir were effective at inhibiting HCMV replication. They partly fulfil requirements for use as safe and effective therapeutics during pregnancy to control congenital HCMV. Clinical trials of these newer agents would assist assessment of their utility in pregnancy.
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56
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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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57
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Repair of an Attenuated Low-Passage Murine Cytomegalovirus Bacterial Artificial Chromosome Identifies a Novel Spliced Gene Essential for Salivary Gland Tropism. J Virol 2020; 94:JVI.01456-20. [PMID: 32847854 DOI: 10.1128/jvi.01456-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 08/23/2020] [Indexed: 01/22/2023] Open
Abstract
The cloning of herpesviruses as bacterial artificial chromosomes (BACs) has revolutionized the study of herpesvirus biology, allowing rapid and precise manipulation of viral genomes. Several clinical strains of human cytomegalovirus (HCMV) have been cloned as BACs; however, no low-passage strains of murine CMV (MCMV), which provide a model mimicking these isolates, have been cloned. Here, the low-passage G4 strain of was BAC cloned. G4 carries an m157 gene that does not ligate the natural killer (NK) cell-activating receptor, Ly49H, meaning that unlike laboratory strains of MCMV, this virus replicates well in C57BL/6 mice. This BAC clone exhibited normal replication during acute infection in the spleen and liver but was attenuated for salivary gland tropism. Next-generation sequencing revealed a C-to-A mutation at nucleotide position 188422, located in the 3' untranslated region of sgg1, a spliced gene critical for salivary gland tropism. Repair of this mutation restored tropism for the salivary glands. Transcriptional analysis revealed a novel spliced gene within the sgg1 locus. This small open reading frame (ORF), sgg1.1, starts at the 3' end of the first exon of sgg1 and extends exon 2 of sgg1. This shorter spliced gene is prematurely terminated by the nonsense mutation at nt 188422. Sequence analysis of tissue culture-passaged virus demonstrated that sgg1.1 was stable, although other mutational hot spots were identified. The G4 BAC will allow in vivo studies in a broader range of mice, avoiding the strong NK cell responses seen in B6 mice with other MCMV BAC-derived MCMVs.IMPORTANCE Murine cytomegalovirus (MCMV) is widely used as a model of human CMV (HCMV) infection. However, this model relies on strains of MCMV that have been serially passaged in the laboratory for over four decades. These laboratory strains have been cloned as bacterial artificial chromosomes (BACs), which permits rapid and precise manipulation. Low-passage strains of MCMV add to the utility of the mouse model of HCMV infection but do not exist as cloned BACs. This study describes the first such low-passage MCMV BAC. This BAC-derived G4 was initially attenuated in vivo, with subsequent full genomic sequencing revealing a novel spliced transcript required for salivary gland tropism. These data suggest that MCMV, like HCMV, undergoes tissue culture adaptation that can limit in vivo growth and supports the use of BAC clones as a way of standardizing viral strains and minimizing interlaboratory strain variation.
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58
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Turner DL, Korneev DV, Purdy JG, de Marco A, Mathias RA. The host exosome pathway underpins biogenesis of the human cytomegalovirus virion. eLife 2020; 9:e58288. [PMID: 32910773 PMCID: PMC7556872 DOI: 10.7554/elife.58288] [Citation(s) in RCA: 23] [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: 04/26/2020] [Accepted: 08/26/2020] [Indexed: 02/07/2023] Open
Abstract
Human Cytomegalovirus (HCMV) infects over half the world's population, is a leading cause of congenital birth defects, and poses serious risks for immuno-compromised individuals. To expand the molecular knowledge governing virion maturation, we analysed HCMV virions using proteomics, and identified a significant proportion of host exosome constituents. To validate this acquisition, we characterized exosomes released from uninfected cells, and demonstrated that over 99% of the protein cargo was subsequently incorporated into HCMV virions during infection. This suggested a common membrane origin, and utilization of host exosome machinery for virion assembly and egress. Thus, we selected a panel of exosome proteins for knock down, and confirmed that loss of 7/9 caused significantly less HCMV production. Saliently, we report that VAMP3 is essential for viral trafficking and release of infectious progeny, in various HCMV strains and cell types. Therefore, we establish that the host exosome pathway is intrinsic for HCMV maturation, and reveal new host regulators involved in viral trafficking, virion envelopment, and release. Our findings underpin future investigation of host exosome proteins as important modulators of HCMV replication with antiviral potential.
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Affiliation(s)
- Declan L Turner
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash UniversityVictoriaAustralia
| | - Denis V Korneev
- School of Biological Sciences, Monash UniversityVictoriaAustralia
| | - John G Purdy
- Department of Immunobiology and BIO5 Institute, University of ArizonaTucsonUnited States
| | - Alex de Marco
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology, Monash UniversityVictoriaAustralia
- ARC Centre of Excellence in Advanced Molecular Imaging, Monash UniversityVictoriaAustralia
- University of WarwickCoventryUnited Kingdom
| | - Rommel A Mathias
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash UniversityVictoriaAustralia
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology, Monash UniversityVictoriaAustralia
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59
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Shibamura M, Yoshikawa T, Yamada S, Inagaki T, Nguyen PHA, Fujii H, Harada S, Fukushi S, Oka A, Mizuguchi M, Saijo M. Association of human cytomegalovirus (HCMV) neutralizing antibodies with antibodies to the HCMV glycoprotein complexes. Virol J 2020; 17:120. [PMID: 32746933 PMCID: PMC7397426 DOI: 10.1186/s12985-020-01390-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 07/28/2020] [Indexed: 12/18/2022] Open
Abstract
Background Human cytomegalovirus (HCMV) causes asymptomatic infections, but also causes congenital infections when women were infected with HCMV during pregnancy, and life-threatening diseases in immunocompromised patients. To better understand the mechanism of the neutralization activity against HCMV, the association of HCMV NT antibody titers was assessed with the antibody titers against each glycoprotein complex (gc) of HCMV. Methods Sera collected from 78 healthy adult volunteers were used. HCMV Merlin strain and HCMV clinical isolate strain 1612 were used in the NT assay with the plaque reduction assay, in which both the MRC-5 fibroblasts cells and the RPE-1 epithelial cells were used. Glycoprotein complex of gB, gH/gL complexes (gH/gL/gO and gH/gL/UL128–131A [PC]) and gM/gN were selected as target glycoproteins. 293FT cells expressed with gB, gM/gN, gH/gL/gO, or PC, were prepared and used for the measurement of the antibody titers against each gc in an indirect immunofluorescence assay (IIFA). The correlation between the IIFA titers to each gc and the HCMV-NT titers was evaluated. Results There were no significant correlations between gB-specific IIFA titers and the HCMV-NT titers in epithelial cells or between gM/gN complex-specific IIFA titers and the HCMV-NT titers. On the other hand, there was a statistically significant positive correlation between the IIFA titers to gH/gL complexes and HCMV-NT titers. Conclusions The data suggest that the gH/gL complexes might be the major target to induce NT activity against HCMV.
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Affiliation(s)
- Miho Shibamura
- Department of Virology 1, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo, 162-8640, Japan.,Department of Pediatrics, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
| | - Tomoki Yoshikawa
- Department of Virology 1, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo, 162-8640, Japan
| | - Souichi Yamada
- Department of Virology 1, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo, 162-8640, Japan
| | - Takuya Inagaki
- Department of Virology 1, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo, 162-8640, Japan.,Department of Life Science and Medical Bioscience, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo, Japan
| | - Phu Hoang Anh Nguyen
- Department of Virology 1, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo, 162-8640, Japan.,Department of Developmental Medical Sciences, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
| | - Hikaru Fujii
- Department of Virology 1, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo, 162-8640, Japan.,The Faculty of Veterinary Medicine, Okayama University of Science, Imabari, Ehime, Japan
| | - Shizuko Harada
- Department of Virology 1, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo, 162-8640, Japan
| | - Shuetsu Fukushi
- Department of Virology 1, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo, 162-8640, Japan
| | - Akira Oka
- Department of Pediatrics, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
| | - Masashi Mizuguchi
- Department of Developmental Medical Sciences, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
| | - Masayuki Saijo
- Department of Virology 1, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo, 162-8640, Japan. .,Department of Developmental Medical Sciences, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan.
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Lau B, Kerr K, Gu Q, Nightingale K, Antrobus R, Suárez NM, Stanton RJ, Wang ECY, Weekes MP, Davison AJ. Human Cytomegalovirus Long Non-coding RNA1.2 Suppresses Extracellular Release of the Pro-inflammatory Cytokine IL-6 by Blocking NF-κB Activation. Front Cell Infect Microbiol 2020; 10:361. [PMID: 32793512 PMCID: PMC7387431 DOI: 10.3389/fcimb.2020.00361] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 06/11/2020] [Indexed: 12/16/2022] Open
Abstract
Long non-coding RNAs (lncRNAs) are transcripts of >200 nucleotides that are not translated into functional proteins. Cellular lncRNAs have been shown to act as regulators by interacting with target nucleic acids or proteins and modulating their activities. We investigated the role of RNA1.2, which is one of four major lncRNAs expressed by human cytomegalovirus (HCMV), by comparing the properties of parental virus in vitro with those of deletion mutants lacking either most of the RNA1.2 gene or only the TATA element of the promoter. In comparison with parental virus, these mutants exhibited no growth defects and minimal differences in viral gene expression in human fibroblasts. In contrast, 76 cellular genes were consistently up- or down-regulated by the mutants at both the RNA and protein levels at 72 h after infection. Differential expression of the gene most highly upregulated by the mutants (Tumor protein p63-regulated gene 1-like protein; TPRG1L) was confirmed at both levels by RT-PCR and immunoblotting. Consistent with the known ability of TPRG1L to upregulate IL-6 expression via NF-κB stimulation, RNA1.2 mutant-infected fibroblasts were observed to upregulate IL-6 in addition to TPRG1L. Comparable surface expression of TNF receptors and responsiveness to TNF-α in cells infected by the parental and mutant viruses indicated that activation of signaling by TNF-α is not involved in upregulation of IL-6 by the mutants. In contrast, inhibition of NF-κB activity and knockdown of TPRG1L expression reduced the extracellular release of IL-6 by RNA1.2 mutant-infected cells, thus demonstrating that upregulation of TPRG1L activates NF-κB. The levels of MCP-1 and CXCL1 transcripts were also increased in RNA1.2 mutant-infected cells, further demonstrating the presence of active NF-κB signaling. These results suggest that RNA1.2 plays a role in manipulating intrinsic NF-κB-dependent cytokine and chemokine release during HCMV infection, thereby impacting downstream immune responses.
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Affiliation(s)
- Betty Lau
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Karen Kerr
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Quan Gu
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Katie Nightingale
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Robin Antrobus
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Nicolás M. Suárez
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Richard J. Stanton
- Division of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Eddie C. Y. Wang
- Division of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Michael P. Weekes
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Andrew J. Davison
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
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61
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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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Houldcroft CJ, Jackson SE, Lim EY, Sedikides GX, Davies EL, Atkinson C, McIntosh M, Remmerswaal EBM, Okecha G, Bemelman FJ, Stanton RJ, Reeves M, Wills MR. Assessing Anti-HCMV Cell Mediated Immune Responses in Transplant Recipients and Healthy Controls Using a Novel Functional Assay. Front Cell Infect Microbiol 2020; 10:275. [PMID: 32670891 PMCID: PMC7332694 DOI: 10.3389/fcimb.2020.00275] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 05/08/2020] [Indexed: 12/14/2022] Open
Abstract
HCMV infection, reinfection or reactivation occurs in 60% of untreated solid organ transplant (SOT) recipients. Current clinical approaches to HCMV management include pre-emptive and prophylactic antiviral treatment strategies. The introduction of immune monitoring to better stratify patients at risk of viraemia and HCMV mediated disease could improve clinical management. Current approaches quantify T cell IFNγ responses specific for predominantly IE and pp65 proteins ex vivo, as a proxy for functional control of HCMV in vivo. However, these approaches have only a limited predictive ability. We measured the IFNγ T cell responses to an expanded panel of overlapping peptide pools specific for immunodominant HCMV proteins IE1/2, pp65, pp71, gB, UL144, and US3 in a cohort of D+R- kidney transplant recipients in a longitudinal analysis. Even with this increased antigen diversity, the results show that while all patients had detectable T cell responses, this did not correlate with control of HCMV replication in some. We wished to develop an assay that could directly measure anti-HCMV cell-mediated immunity. We evaluated three approaches, stimulation of PBMC with (i) whole HCMV lysate or (ii) a defined panel of immunodominant HCMV peptides, or (iii) fully autologous infected cells co-cultured with PBMC or isolated CD8+ T cells or NK cells. Stimulation with HCMV lysate often generated non-specific antiviral responses while stimulation with immunodominant HCMV peptide pools produced responses which were not necessarily antiviral despite strong IFNγ production. We demonstrated that IFNγ was only a minor component of secreted antiviral activity. Finally, we used an antiviral assay system to measure the effect of whole PBMC, and isolated CD8+ T cells and NK cells to control HCMV in infected autologous dermal fibroblasts. The results show that both PBMC and especially CD8+ T cells from HCMV seropositive donors have highly specific antiviral activity against HCMV. In addition, we were able to show that NK cells were also antiviral, but the level of this control was highly variable between donors and not dependant on HCMV seropositivity. Using this approach, we show that non-viraemic D+R+ SOT recipients had significant and specific antiviral activity against HCMV.
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Affiliation(s)
- Charlotte J. Houldcroft
- Department of Medicine, Addenbrookes Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Sarah E. Jackson
- Department of Medicine, Addenbrookes Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Eleanor Y. Lim
- Department of Medicine, Addenbrookes Hospital, University of Cambridge, Cambridge, United Kingdom
| | - George X. Sedikides
- Department of Medicine, Addenbrookes Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Emma L. Davies
- Department of Medicine, Addenbrookes Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Claire Atkinson
- Division of Infection and Immunity, Institute for Immunity and Transplantation, University College London, London, United Kingdom
| | - Megan McIntosh
- Division of Infection and Immunity, Institute for Immunity and Transplantation, University College London, London, United Kingdom
| | - Ester B. M. Remmerswaal
- Department of Experimental Immunology, Amsterdam Infection and Immunity Institute, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Renal Transplant Unit, Division of Internal Medicine, Academic Medical Centre, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Georgina Okecha
- Department of Medicine, Addenbrookes Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Frederike J. Bemelman
- Department of Experimental Immunology, Amsterdam Infection and Immunity Institute, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Renal Transplant Unit, Division of Internal Medicine, Academic Medical Centre, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Richard J. Stanton
- Division of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Matthew Reeves
- Division of Infection and Immunity, Institute for Immunity and Transplantation, University College London, London, United Kingdom
| | - Mark R. Wills
- Department of Medicine, Addenbrookes Hospital, University of Cambridge, Cambridge, United Kingdom
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Park J, Gill KS, Aghajani AA, Heredia JD, Choi H, Oberstein A, Procko E. Engineered receptors for human cytomegalovirus that are orthogonal to normal human biology. PLoS Pathog 2020; 16:e1008647. [PMID: 32559251 PMCID: PMC7329128 DOI: 10.1371/journal.ppat.1008647] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 07/01/2020] [Accepted: 05/20/2020] [Indexed: 12/12/2022] Open
Abstract
A trimeric glycoprotein complex on the surface of human cytomegalovirus (HCMV) binds to platelet-derived growth factor (PDGF) receptor α (PDGFRα) to mediate host cell recognition and fusion of the viral and cellular membranes. Soluble PDGFRα potently neutralizes HCMV in tissue culture, and its potential use as an antiviral therapeutic has the benefit that any escape mutants will likely be attenuated. However, PDGFRα binds multiple PDGF ligands in the human body as part of developmental programs in embryogenesis and continuing through adulthood. Any therapies with soluble receptor therefore come with serious efficacy and safety concerns, especially for the treatment of congenital HCMV. Soluble virus receptors that are orthogonal to human biology might resolve these concerns. This engineering problem is solved by deep mutational scanning on the D2-D3 domains of PDGFRα to identify variants that maintain interactions with the HCMV glycoprotein trimer in the presence of competing PDGF ligands. Competition by PDGFs is conformation-dependent, whereas HCMV trimer binding is independent of proper D2-D3 conformation, and many mutations at the receptor-PDGF interface are suitable for functionally separating trimer from PDGF interactions. Purified soluble PDGFRα carrying a targeted mutation succeeded in displaying wild type affinity for HCMV trimer with a simultaneous loss of PDGF binding, and neutralizes trimer-only and trimer/pentamer-expressing HCMV strains infecting fibroblasts or epithelial cells. Overall, this work makes important progress in the realization of soluble HCMV receptors for clinical application. Human cytomegalovirus (HCMV) causes severe disease in transplant recipients and immunocompromised patients, and infections in a fetus or neonate are responsible for life-long neurological defects. Cell entry is in part mediated by a trimeric glycoprotein complex on the viral surface, which binds tightly to the host receptor PDGFRα. The soluble extracellular region of PDGFRα can be used as an antiviral agent to potently neutralize the virus in vitro. However, PDGFRα ordinarily binds growth factors in the human body to regulate developmental programs, which will limit the in vivo efficacy and safety of soluble PDGFRα. Using saturation mutagenesis and selections in human cell culture, mutations in PDGFRα are identified that eliminate off-target growth factor interactions while preserving HCMV binding and neutralization.
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Affiliation(s)
- Jihye Park
- Department of Biochemistry, University of Illinois, Urbana, Illinois, United States of America
| | - Kevin Sean Gill
- Department of Biochemistry, University of Illinois, Urbana, Illinois, United States of America
| | - Ali Asghar Aghajani
- Department of Biochemistry, University of Illinois, Urbana, Illinois, United States of America
| | - Jeremiah Dallas Heredia
- Department of Biochemistry, University of Illinois, Urbana, Illinois, United States of America
| | - Hannah Choi
- Department of Biochemistry, University of Illinois, Urbana, Illinois, United States of America
| | - Adam Oberstein
- Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago, Illinois, United States of America
| | - Erik Procko
- Department of Biochemistry, University of Illinois, Urbana, Illinois, United States of America
- Cancer Center at Illinois (CCIL), University of Illinois, Urbana, Illinois, United States of America
- * E-mail:
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64
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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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65
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A quantitative nuclear egress assay to investigate the nucleocytoplasmic capsid release of human cytomegalovirus. J Virol Methods 2020; 283:113909. [PMID: 32544419 DOI: 10.1016/j.jviromet.2020.113909] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 06/05/2020] [Accepted: 06/07/2020] [Indexed: 11/21/2022]
Abstract
Nuclear egress is a rate-limiting step of herpesviral replication, restricting the nucleocytoplasmic transport of viral capsids. The process is regulated by two viral nuclear egress proteins (core NEC pUL50-pUL53), which recruit additional cellular and viral proteins. The multicomponent NEC mediates disassembly of the nuclear lamina barrier and the docking of nuclear capsids. The quantitation of nuclear egress has been accomplished by electron microscopic analysis, but is generally hampered by the low number of detectable cytoplasmic capsids. A newly established method for the quantitation of viral nuclear egress improves the characterization of viral mutants, host cell permissiveness and antiviral drug efficacy. In this study, various strains of human cytomegalovirus (HCMV) were used to measure the replication efficiencies in primary human fibroblasts, applying methods of cell fractionation, DNase digestion, sucrose cushions and quantitative PCR. Several stages of optimization led to a reliable quantitative assay that allowed the characterization of viral nuclear egress efficacy. Using this assay, recovery of the nuclear egress of a NEC-defective HCMV mutant was quantitatively assessed by applying an inducible NEC-expressing fibroblast culture for trans-complementation. This novel assay system can be further used to accurately quantitate and characterize the functionality of nuclear egress of HCMV or other herpesviruses.
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66
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van Senten JR, Bebelman MP, van Gasselt P, Bergkamp ND, van den Bor J, Siderius M, Smit MJ. Human Cytomegalovirus-Encoded G Protein-Coupled Receptor UL33 Facilitates Virus Dissemination via the Extracellular and Cell-to-Cell Route. Viruses 2020; 12:v12060594. [PMID: 32486172 PMCID: PMC7354556 DOI: 10.3390/v12060594] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 05/25/2020] [Accepted: 05/27/2020] [Indexed: 02/06/2023] Open
Abstract
Human cytomegalovirus (HCMV) encodes four G protein-coupled receptor (GPCR) homologs. Three of these receptors, UL78, US27 and US28, are known for their roles in HCMV dissemination and latency. Despite importance of its rodent orthologs for viral replication and pathogenesis, such a function is not reported for the HCMV-encoded GPCR UL33. Using the clinical HCMV strain Merlin, we show that UL33 facilitates both cell-associated and cell-free virus transmission. A UL33-deficient virus derivative revealed retarded virus spread, formation of less and smaller plaques, and reduced extracellular progeny during multi-cycle growth analysis in fibroblast cultures compared to parental virus. The growth of UL33-revertant, US28-deficient, and US28-revertant viruses were similar to parental virus under multistep growth conditions. UL33- and US28-deficient Merlin viruses impaired cell-associated virus spread to a similar degree. Thus, the growth defect displayed by the UL33-deficient virus but not the US28-deficient virus reflects UL33's contribution to extracellular transmission. In conclusion, UL33 facilitates cell-associated and cell-free spread of the clinical HCMV strain Merlin in fibroblast cultures.
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67
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Suárez NM, Wilkie GS, Hage E, Camiolo S, Holton M, Hughes J, Maabar M, Vattipally SB, Dhingra A, Gompels UA, Wilkinson GWG, Baldanti F, Furione M, Lilleri D, Arossa A, Ganzenmueller T, Gerna G, Hubáček P, Schulz TF, Wolf D, Zavattoni M, Davison AJ. Human Cytomegalovirus Genomes Sequenced Directly From Clinical Material: Variation, Multiple-Strain Infection, Recombination, and Gene Loss. J Infect Dis 2020; 220:781-791. [PMID: 31050742 PMCID: PMC6667795 DOI: 10.1093/infdis/jiz208] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 04/24/2019] [Indexed: 11/29/2022] Open
Abstract
The genomic characteristics of human cytomegalovirus (HCMV) strains sequenced directly from clinical pathology samples were investigated, focusing on variation, multiple-strain infection, recombination, and gene loss. A total of 207 datasets generated in this and previous studies using target enrichment and high-throughput sequencing were analyzed, in the process enabling the determination of genome sequences for 91 strains. Key findings were that (i) it is important to monitor the quality of sequencing libraries in investigating variation; (ii) many recombinant strains have been transmitted during HCMV evolution, and some have apparently survived for thousands of years without further recombination; (iii) mutants with nonfunctional genes (pseudogenes) have been circulating and recombining for long periods and can cause congenital infection and resulting clinical sequelae; and (iv) intrahost variation in single-strain infections is much less than that in multiple-strain infections. Future population-based studies are likely to continue illuminating the evolution, epidemiology, and pathogenesis of HCMV.
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Affiliation(s)
- Nicolás M Suárez
- Medical Research Council-University of Glasgow Centre for Virus Research, United Kingdom
| | - Gavin S Wilkie
- Medical Research Council-University of Glasgow Centre for Virus Research, United Kingdom
| | - Elias Hage
- Institute of Virology, Hannover Medical School, United Kingdom.,German Center for Infection Research, Hannover-Braunschweig site, United Kingdom
| | - Salvatore Camiolo
- Medical Research Council-University of Glasgow Centre for Virus Research, United Kingdom
| | - Marylouisa Holton
- Medical Research Council-University of Glasgow Centre for Virus Research, United Kingdom
| | - Joseph Hughes
- Medical Research Council-University of Glasgow Centre for Virus Research, United Kingdom
| | - Maha Maabar
- Medical Research Council-University of Glasgow Centre for Virus Research, United Kingdom
| | - Sreenu B Vattipally
- Medical Research Council-University of Glasgow Centre for Virus Research, United Kingdom
| | - Akshay Dhingra
- Institute of Virology, Hannover Medical School, United Kingdom
| | - Ursula A Gompels
- Pathogen Molecular Biology Department, London School of Hygiene and Tropical Medicine, United Kingdom
| | - Gavin W G Wilkinson
- Division of Infection and Immunity, School of Medicine, Cardiff University, United Kingdom
| | - Fausto Baldanti
- Molecular Virology Unit, Microbiology and Virology Department, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Policlinico San Matteo, Italy.,Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, Italy
| | - Milena Furione
- Molecular Virology Unit, Microbiology and Virology Department, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Policlinico San Matteo, Italy
| | - Daniele Lilleri
- Laboratory of Genetics-Transplantology and Cardiovascular Diseases, Italy
| | - Alessia Arossa
- Departments of Obstetrics and Gynecology, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Tina Ganzenmueller
- Institute of Virology, Hannover Medical School, United Kingdom.,German Center for Infection Research, Hannover-Braunschweig site, United Kingdom.,Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tuebingen, Germany
| | - Giuseppe Gerna
- Laboratory of Genetics-Transplantology and Cardiovascular Diseases, Italy
| | - Petr Hubáček
- Department of Medical Microbiology, Motol University Hospital, Prague, Czech Republic, Israel
| | - Thomas F Schulz
- Institute of Virology, Hannover Medical School, United Kingdom.,German Center for Infection Research, Hannover-Braunschweig site, United Kingdom
| | - Dana Wolf
- Clinical Virology Unit, Department of Clinical Microbiology and Infectious Diseases, Hadassah University Hospital, Jerusalem, Israel
| | - Maurizio Zavattoni
- Molecular Virology Unit, Microbiology and Virology Department, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Policlinico San Matteo, Italy
| | - Andrew J Davison
- Medical Research Council-University of Glasgow Centre for Virus Research, United Kingdom
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Human Cytomegalovirus Congenital (cCMV) Infection Following Primary and Nonprimary Maternal Infection: Perspectives of Prevention through Vaccine Development. Vaccines (Basel) 2020; 8:vaccines8020194. [PMID: 32340180 PMCID: PMC7349293 DOI: 10.3390/vaccines8020194] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 04/13/2020] [Accepted: 04/18/2020] [Indexed: 01/26/2023] Open
Abstract
Congenital cytomegalovirus (cCMV) might occur as a result of the human cytomegalovirus (HCMV) primary (PI) or nonprimary infection (NPI) in pregnant women. Immune correlates of protection against cCMV have been partly identified only for PI. Following either PI or NPI, HCMV strains undergo latency. From a diagnostic standpoint, while the serological criteria for the diagnosis of PI are well-established, those for the diagnosis of NPI are still incomplete. Thus far, a recombinant gB subunit vaccine has provided the best results in terms of partial protection. This partial efficacy was hypothetically attributed to the post-fusion instead of the pre-fusion conformation of the gB present in the vaccine. Future efforts should be addressed to verify whether a new recombinant gB pre-fusion vaccine would provide better results in terms of prevention of both PI and NPI. It is still a matter of debate whether human hyperimmune globulin are able to protect from HCMV vertical transmission. In conclusion, the development of an HCMV vaccine that would prevent a significant portion of PI would be a major step forward in the development of a vaccine for both PI and NPI.
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69
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van Senten JR, Fan TS, Siderius M, Smit MJ. Viral G protein-coupled receptors as modulators of cancer hallmarks. Pharmacol Res 2020; 156:104804. [PMID: 32278040 DOI: 10.1016/j.phrs.2020.104804] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 04/02/2020] [Accepted: 04/03/2020] [Indexed: 12/12/2022]
Abstract
Herpesviruses encode transmembrane G protein-coupled receptors (GPCRs), which share structural homology to human chemokine receptors. These viral GPCRs include KSHV-encoded ORF74, EBV-encoded BILF1, and HCMV-encoded US28, UL33, UL78 and US27. Viral GPCRs hijack various signaling pathways and cellular networks, including pathways involved in the so-called cancer hallmarks as defined by Hanahan and Weinberg. These hallmarks describe cellular characteristics crucial for transformation and tumor progression. The cancer hallmarks involve growth factor-independent proliferation, angiogenesis, avoidance of apoptosis, invasion and metastasis, metabolic reprogramming, genetic instability and immune evasion amongst others. The role of beta herpesviruses modulating these cancer hallmarks is clearly highlighted by the proliferative and pro-angiogenic phenotype associated with KSHV infection which is largely ascribed to the ORF74-mediated modulation of signaling networks in host cells. For HCMV and Epstein-Bar encoded GPCRs, oncomodulatory effects have been described which contribute to the cancer hallmarks, thereby enhancing oncogenic development. In this review, we describe the main signaling pathways controlling the hallmarks of cancer which are affected by the betaherpesvirus encoded GPCRs. Most prominent among these involve the JAK-STAT, PI(3)K-AKT, NFkB and MAPK signaling nodes. These insights are important to effectively target these viral GPCRs and their signaling networks in betaherpesvirus-associated malignancies.
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Affiliation(s)
- Jeffrey R van Senten
- Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands
| | - Tian Shu Fan
- Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands
| | - Marco Siderius
- Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands
| | - Martine J Smit
- Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands.
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Tai-Schmiedel J, Karniely S, Lau B, Ezra A, Eliyahu E, Nachshon A, Kerr K, Suárez N, Schwartz M, Davison AJ, Stern-Ginossar N. Human cytomegalovirus long noncoding RNA4.9 regulates viral DNA replication. PLoS Pathog 2020; 16:e1008390. [PMID: 32294138 PMCID: PMC7185721 DOI: 10.1371/journal.ppat.1008390] [Citation(s) in RCA: 25] [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: 10/10/2019] [Revised: 04/27/2020] [Accepted: 02/07/2020] [Indexed: 01/25/2023] Open
Abstract
Viruses are known for their extremely compact genomes composed almost entirely of protein-coding genes. Nonetheless, four long noncoding RNAs (lncRNAs) are encoded by human cytomegalovirus (HCMV). Although these RNAs accumulate to high levels during lytic infection, their functions remain largely unknown. Here, we show that HCMV-encoded lncRNA4.9 localizes to the viral nuclear replication compartment, and that its depletion restricts viral DNA replication and viral growth. RNA4.9 is transcribed from the HCMV origin of replication (oriLyt) and forms an RNA-DNA hybrid (R-loop) through its G+C-rich 5' end, which may be important for the initiation of viral DNA replication. Furthermore, targeting the RNA4.9 promoter with CRISPR-Cas9 or genetic relocalization of oriLyt leads to reduced levels of the viral single-stranded DNA-binding protein (ssDBP), suggesting that the levels of ssDBP are coupled to the oriLyt activity. We further identified a similar, oriLyt-embedded, G+C-rich lncRNA in murine cytomegalovirus (MCMV). These results indicate that HCMV RNA4.9 plays an important role in regulating viral DNA replication, that the levels of ssDBP are coupled to the oriLyt activity, and that these regulatory features may be conserved among betaherpesviruses.
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Affiliation(s)
- Julie Tai-Schmiedel
- Weizmann Institute of Science, Department of Molecular Genetics, Rehovot, Israel
| | | | - Betty Lau
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Adi Ezra
- Weizmann Institute of Science, Department of Molecular Genetics, Rehovot, Israel
| | - Erez Eliyahu
- Weizmann Institute of Science, Department of Molecular Genetics, Rehovot, Israel
| | - Aharon Nachshon
- Weizmann Institute of Science, Department of Molecular Genetics, Rehovot, Israel
| | - Karen Kerr
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Nicolás Suárez
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Michal Schwartz
- Weizmann Institute of Science, Department of Molecular Genetics, Rehovot, Israel
| | - Andrew J Davison
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Noam Stern-Ginossar
- Weizmann Institute of Science, Department of Molecular Genetics, Rehovot, Israel
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71
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Polymorphisms in Human Cytomegalovirus Glycoprotein O (gO) Exert Epistatic Influences on Cell-Free and Cell-to-Cell Spread and Antibody Neutralization on gH Epitopes. J Virol 2020; 94:JVI.02051-19. [PMID: 31996433 DOI: 10.1128/jvi.02051-19] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 01/24/2020] [Indexed: 02/06/2023] Open
Abstract
Human cytomegalovirus (HCMV) glycoproteins H and L (gH/gL) can be bound by either gO or the UL128 to UL131 proteins (referred to here as UL128-131) to form complexes that facilitate entry and spread, and the complexes formed are important targets of neutralizing antibodies. Strains of HCMV vary considerably in the levels of gH/gL/gO and gH/gL/UL128-131, and this can impact infectivity and cell tropism. In this study, we investigated how natural interstrain variation in the amino acid sequence of gO influences the biology of HCMV. Heterologous gO recombinants were constructed in which 6 of the 8 alleles or genotypes (GT) of gO were analyzed in the backgrounds of strains TR and Merlin (ME). The levels of gH/gL complexes were not affected, but there were impacts on entry, spread, and neutralization by anti-gH antibodies. AD169 (AD) gO (GT1a) [referred to here as ADgO(GT1a)] drastically reduced cell-free infectivity of both strains on fibroblasts and epithelial cells. PHgO(GT2a) increased cell-free infectivity of TR in both cell types, but spread in fibroblasts was impaired. In contrast, spread of ME in both cell types was enhanced by Towne (TN) gO (GT4), despite similar cell-free infectivity. TR expressing TNgO(GT4) was resistant to neutralization by anti-gH antibodies AP86 and 14-4b, whereas ADgO(GT1a) conferred resistance to 14-4b but enhanced neutralization by AP86. Conversely, ME expressing ADgO(GT1a) was more resistant to 14-4b. These results suggest that (i) there are mechanistically distinct roles for gH/gL/gO in cell-free and cell-to-cell spread, (ii) gO isoforms can differentially shield the virus from neutralizing antibodies, and (iii) effects of gO polymorphisms are epistatically dependent on other variable loci.IMPORTANCE Advances in HCMV population genetics have greatly outpaced understanding of the links between genetic diversity and phenotypic variation. Moreover, recombination between genotypes may shuffle variable loci into various combinations with unknown outcomes. UL74(gO) is an important determinant of HCMV infectivity and one of the most diverse loci in the viral genome. By analyzing interstrain heterologous UL74(gO) recombinants, we showed that gO diversity can have dramatic impacts on cell-free and cell-to-cell spread as well as on antibody neutralization and that the manifestation of these impacts can be subject to epistatic influences of the global genetic background. These results highlight the potential limitations of laboratory studies of HCMV biology that use single, isolated genotypes or strains.
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72
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Evasion of a Human Cytomegalovirus Entry Inhibitor with Potent Cysteine Reactivity Is Concomitant with the Utilization of a Heparan Sulfate Proteoglycan-Independent Route of Entry. J Virol 2020; 94:JVI.02012-19. [PMID: 31941787 PMCID: PMC7081914 DOI: 10.1128/jvi.02012-19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 01/09/2020] [Indexed: 01/22/2023] Open
Abstract
The dependence of viruses on the host cell to complete their replicative cycle renders cellular functions potential targets for novel antivirals. We screened a panel of broadly acting cellular ion channel inhibitors for activity against human cytomegalovirus (HCMV) and identified the voltage-gated chloride ion channel inhibitor 4,4'-diisothiocyano-2,2'-stilbenedisulfonic acid (DIDS) as a potent inhibitor of HCMV replication. Time-of-addition studies demonstrated that DIDS inhibited entry via direct interaction with the virion that impeded binding to the plasma membrane. Synthesis and analysis of pharmacological variants of DIDS suggested that intrinsic cysteine, and not lysine, reactivity was important for activity against HCMV. Although sequencing of DIDS-resistant HCMV revealed enrichment of a mutation within UL100 (encoding glycoprotein M) and a specific truncation of glycoprotein RL13, these did not explain the DIDS resistance phenotype. Specifically, only the introduction of the RL13 mutant partially phenocopied the DIDS resistance phenotype. Serendipitously, the entry of DIDS-resistant HCMV also became independent of heparan sulfate proteoglycans (HSPGs), suggesting that evasion of DIDS lowered dependence on an initial interaction with HSPGs. Intriguingly, the DIDS-resistant virus demonstrated increased sensitivity to antibody neutralization, which mapped, in part, to the presence of the gM mutation. Taken together the data characterize the antiviral activity of a novel HCMV inhibitor that drives HCMV infection to occur independently of HSPGs and the generation of increased sensitivity to humoral immunity. The data also demonstrate that compounds with cysteine reactivity have the potential to act as antiviral compounds against HCMV via direct engagement of virions.IMPORTANCE Human cytomegalovirus (HCMV) is major pathogen of nonimmunocompetent individuals that remains in need of new therapeutic options. Here, we identify a potent antiviral compound (4,4'-diisothiocyano-2,2'-stilbenedisulfonic acid [DIDS]), its mechanism of action, and the chemical properties required for its activity. In doing so, the data argue that cysteine-reactive compounds could have the capacity to be developed for anti-HCMV activity. Importantly, the data show that entry of DIDS-resistant virus became independent of heparan sulfate proteoglycans (HSPGs) but, concomitantly, became more sensitive to neutralizing antibody responses. This serendipitous observation suggests that retention of an interaction with HSPGs during the entry process in vivo may be evolutionarily advantageous through better evasion of humoral responses directed against HCMV virions.
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73
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Roark HK, Jenks JA, Permar SR, Schleiss MR. Animal Models of Congenital Cytomegalovirus Transmission: Implications for Vaccine Development. J Infect Dis 2020; 221:S60-S73. [PMID: 32134481 PMCID: PMC7057791 DOI: 10.1093/infdis/jiz484] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Although cytomegaloviruses (CMVs) are species-specific, the study of nonhuman CMVs in animal models can help to inform and direct research aimed at developing a human CMV (HCMV) vaccine. Because the driving force behind the development of HCMV vaccines is to prevent congenital infection, the animal model in question must be one in which vertical transmission of virus occurs to the fetus. Fortunately, two such animal models-the rhesus macaque CMV and guinea pig CMV-are characterized by congenital infection. Hence, each model can be evaluated in "proof-of-concept" studies of preconception vaccination aimed at blocking transplacental transmission. This review focuses on similarities and differences in the respective model systems, and it discusses key insights from each model germane to the study of HCMV vaccines.
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Affiliation(s)
- Hunter K Roark
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, USA
| | - Jennifer A Jenks
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, USA
| | - Sallie R Permar
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, USA
| | - Mark R Schleiss
- Center for Infectious Diseases and Microbiology Translational Research, University of Minnesota Medical School, Department of Pediatrics, Division of Pediatric Infectious Diseases and Immunology, Minneapolis, Minnesota, USA
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74
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Differential Expression of PDGF Receptor-α in Human Placental Trophoblasts Leads to Different Entry Pathways by Human Cytomegalovirus Strains. Sci Rep 2020; 10:1082. [PMID: 31974453 PMCID: PMC6978357 DOI: 10.1038/s41598-020-57471-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 12/12/2019] [Indexed: 12/14/2022] Open
Abstract
Human cytomegalovirus (CMV) is the leading non-genetic cause of fetal malformation in developed countries. CMV placental infection is a pre-requisite for materno-fetal transmission of virus, and fetal infection. We investigated the roles of the viral pentameric complex gH/gL/pUL128-pUL131A, and cellular platelet-derived growth factor receptor-α (PDGFRα) for CMV infection in first trimester extravillous-derived (SGHPL-4) and villous-derived (HTR-8/SVneo) trophoblast cells. Infection with four CMV clinical and laboratory strains (Merlin, TB40E, Towne, AD169), and Merlin deletion mutants of UL128-, UL130-, and UL131A-genes, showed a cell type-dependent requirement of the viral pentameric complex for infection of trophoblast cells. The viral pentameric complex was essential for infection of villous trophoblasts, but non-essential for extravillous trophoblasts. Blocking of PDGFRα in extravillous trophoblasts, which naturally express PDGFRα, inhibited entry of pentameric complex-deficient CMV strains, but not the entry of pentameric positive CMV strains. Transient expression of PDGFRα in villous trophoblasts, which are naturally deficient in PDGFRα, promoted the entry of CMV strains lacking gH/gL/pUL128-pUL131A, but had no effect on entry of pentameric positive CMV strains. These results suggest PDGFRα is an important cell receptor for entry of CMV mutant strains lacking gH/gL/pUL128-pUL131A complexes in some placental cells, suggesting these entry pathways could be potential antiviral targets.
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75
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Nobre LV, Nightingale K, Ravenhill BJ, Antrobus R, Soday L, Nichols J, Davies JA, Seirafian S, Wang ECY, Davison AJ, Wilkinson GWG, Stanton RJ, Huttlin EL, Weekes MP. Human cytomegalovirus interactome analysis identifies degradation hubs, domain associations and viral protein functions. eLife 2019; 8:e49894. [PMID: 31873071 PMCID: PMC6959991 DOI: 10.7554/elife.49894] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 12/24/2019] [Indexed: 02/07/2023] Open
Abstract
Human cytomegalovirus (HCMV) extensively modulates host cells, downregulating >900 human proteins during viral replication and degrading ≥133 proteins shortly after infection. The mechanism of degradation of most host proteins remains unresolved, and the functions of many viral proteins are incompletely characterised. We performed a mass spectrometry-based interactome analysis of 169 tagged, stably-expressed canonical strain Merlin HCMV proteins, and two non-canonical HCMV proteins, in infected cells. This identified a network of >3400 virus-host and >150 virus-virus protein interactions, providing insights into functions for multiple viral genes. Domain analysis predicted binding of the viral UL25 protein to SH3 domains of NCK Adaptor Protein-1. Viral interacting proteins were identified for 31/133 degraded host targets. Finally, the uncharacterised, non-canonical ORFL147C protein was found to interact with elements of the mRNA splicing machinery, and a mutational study suggested its importance in viral replication. The interactome data will be important for future studies of herpesvirus infection.
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Affiliation(s)
- Luis V Nobre
- Cambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUnited Kingdom
| | - Katie Nightingale
- Cambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUnited Kingdom
| | - Benjamin J Ravenhill
- Cambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUnited Kingdom
| | - Robin Antrobus
- Cambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUnited Kingdom
| | - Lior Soday
- Cambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUnited Kingdom
| | - Jenna Nichols
- MRC-University of Glasgow Centre for Virus ResearchGlasgowUnited Kingdom
| | - James A Davies
- Division of Infection and ImmunityCardiff University School of MedicineCardiffUnited Kingdom
| | - Sepehr Seirafian
- Division of Infection and ImmunityCardiff University School of MedicineCardiffUnited Kingdom
| | - Eddie CY Wang
- Division of Infection and ImmunityCardiff University School of MedicineCardiffUnited Kingdom
| | - Andrew J Davison
- MRC-University of Glasgow Centre for Virus ResearchGlasgowUnited Kingdom
| | - Gavin WG Wilkinson
- Division of Infection and ImmunityCardiff University School of MedicineCardiffUnited Kingdom
| | - Richard J Stanton
- Division of Infection and ImmunityCardiff University School of MedicineCardiffUnited Kingdom
| | - Edward L Huttlin
- Department of Cell BiologyHarvard Medical SchoolBostonUnited States
| | - Michael P Weekes
- Cambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUnited Kingdom
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76
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Caposio P, van den Worm S, Crawford L, Perez W, Kreklywich C, Gilbride RM, Hughes CM, Ventura AB, Ratts R, Marshall EE, Malouli D, Axthelm MK, Streblow D, Nelson JA, Picker LJ, Hansen SG, Früh K. Characterization of a live-attenuated HCMV-based vaccine platform. Sci Rep 2019; 9:19236. [PMID: 31848362 PMCID: PMC6917771 DOI: 10.1038/s41598-019-55508-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 11/29/2019] [Indexed: 02/07/2023] Open
Abstract
Vaccines based on cytomegalovirus (CMV) demonstrate protection in animal models of infectious disease and cancer. Vaccine efficacy is associated with the ability of CMV to elicit and indefinitely maintain high frequencies of circulating effector memory T cells (TEM) providing continuous, life-long anti-pathogen immune activity. To allow for the clinical testing of human CMV (HCMV)-based vaccines we constructed and characterized as a vector backbone the recombinant molecular clone TR3 representing a wildtype genome. We demonstrate that TR3 can be stably propagated in vitro and that, despite species incompatibility, recombinant TR3 vectors elicit high frequencies of TEM to inserted antigens in rhesus macaques (RM). Live-attenuated versions of TR3 were generated by deleting viral genes required to counteract intrinsic and innate immune responses. In addition, we eliminated subunits of a viral pentameric glycoprotein complex thus limiting cell tropism. We show in a humanized mouse model that such modified vectors were able to establish persistent infection but lost their ability to reactivate from latency. Nevertheless, attenuated TR3 vectors preserved the ability to elicit and maintain TEM to inserted antigens in RM. We further demonstrate that attenuated TR3 can be grown in approved cell lines upon elimination of an anti-viral host factor using small interfering RNA, thus obviating the need for a complementing cell line. In sum, we have established a versatile platform for the clinical development of live attenuated HCMV-vectored vaccines and immunotherapies.
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Affiliation(s)
- Patrizia Caposio
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, 97006, USA
| | - Sjoerd van den Worm
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, 97006, USA
- Batavia Biosciences B.V., Zernikedreef 16, 2333 CL, Leiden, Netherlands
| | - Lindsey Crawford
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, 97006, USA
| | - Wilma Perez
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, 97006, USA
| | - Craig Kreklywich
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, 97006, USA
| | - Roxanne M Gilbride
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, 97006, USA
| | - Colette M Hughes
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, 97006, USA
| | - Abigail B Ventura
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, 97006, USA
| | - Robert Ratts
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, 97006, USA
- Vir Biotechnology, 4640, SW Macadam Avenue, Portland, OR, 97239, USA
| | - Emily E Marshall
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, 97006, USA
- Vir Biotechnology, 4640, SW Macadam Avenue, Portland, OR, 97239, USA
| | - Daniel Malouli
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, 97006, USA
| | - Michael K Axthelm
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, 97006, USA
| | - Daniel Streblow
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, 97006, USA
| | - Jay A Nelson
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, 97006, USA
| | - Louis J Picker
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, 97006, USA
| | - Scott G Hansen
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, 97006, USA.
| | - Klaus Früh
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, 97006, USA.
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77
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Zhang H, Read C, Nguyen CC, Siddiquey MNA, Shang C, Hall CM, von Einem J, Kamil JP. The Human Cytomegalovirus Nonstructural Glycoprotein UL148 Reorganizes the Endoplasmic Reticulum. mBio 2019; 10:e02110-19. [PMID: 31822584 PMCID: PMC6904874 DOI: 10.1128/mbio.02110-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 10/29/2019] [Indexed: 12/17/2022] Open
Abstract
Human cytomegalovirus (HCMV) encodes an endoplasmic reticulum (ER)-resident glycoprotein, UL148, which activates the unfolded protein response (UPR) but is fully dispensable for viral replication in cultured cells. Hence, its previously ascribed roles in immune evasion and modulation of viral cell tropism are hypothesized to cause ER stress. Here, we show that UL148 is necessary and sufficient to drive the formation of prominent ER-derived structures that on average occupy 5% of the infected cell cytoplasm. The structures are sites where UL148 coalesces with cellular proteins involved in ER quality control, such as HRD1 and EDEM1. Electron microscopy revealed that cells infected with wild-type but not UL148-null HCMV show prominent accumulations of densely packed ruffled ER membranes which connect to distended cisternae of smooth and partially rough ER. During ectopic expression of UL148-green fluorescent protein (GFP) fusion protein, punctate signals traffic to accumulate at conspicuous structures. The structures exhibit poor recovery of fluorescence after photobleaching, which suggests that their contents are poorly mobile and do not efficiently exchange with the rest of the ER. Small-molecule blockade of the integrated stress response (ISR) prevents the formation of puncta, leading to a uniform reticular fluorescent signal. Accordingly, ISR inhibition during HCMV infection abolishes the coalescence of UL148 and HRD1 into discrete structures, which argues that UL148 requires the ISR to cause ER reorganization. Given that UL148 stabilizes immature forms of a receptor binding subunit for a viral envelope glycoprotein complex important for HCMV infectivity, our results imply that stress-dependent ER remodeling contributes to viral cell tropism.IMPORTANCE Perturbations to endoplasmic reticulum (ER) morphology occur during infection with various intracellular pathogens and in certain genetic disorders. We identify that a human cytomegalovirus (HCMV) gene product, UL148, profoundly reorganizes the ER during infection and is sufficient to do so when expressed on its own. Our results reveal that UL148-dependent reorganization of the ER is a prominent feature of HCMV-infected cells. Moreover, we find that this example of virally induced organelle remodeling requires the integrated stress response (ISR), a stress adaptation pathway that contributes to a number of disease states. Since ER reorganization accompanies roles of UL148 in modulation of HCMV cell tropism and in evasion of antiviral immune responses, our results may have implications for understanding the mechanisms involved. Furthermore, our findings provide a basis to utilize UL148 as a tool to investigate organelle responses to stress and to identify novel drugs targeting the ISR.
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Affiliation(s)
- Hongbo Zhang
- Department of Microbiology and Immunology, LSU Health Sciences Center, Shreveport, Louisiana, USA
| | - Clarissa Read
- Institute of Virology, Ulm University Medical Center, Ulm, Germany
- Central Facility for Electron Microscopy, Ulm University, Ulm, Germany
| | - Christopher C Nguyen
- Department of Microbiology and Immunology, LSU Health Sciences Center, Shreveport, Louisiana, USA
| | - Mohammed N A Siddiquey
- Department of Microbiology and Immunology, LSU Health Sciences Center, Shreveport, Louisiana, USA
| | - Chaowei Shang
- Research Core Facility, LSU Health Sciences Center, Shreveport, Louisiana, USA
| | - Cameron M Hall
- Department of Microbiology and Immunology, LSU Health Sciences Center, Shreveport, Louisiana, USA
| | - Jens von Einem
- Institute of Virology, Ulm University Medical Center, Ulm, Germany
| | - Jeremy P Kamil
- Department of Microbiology and Immunology, LSU Health Sciences Center, Shreveport, Louisiana, USA
- Center for Molecular and Tumor Virology, LSU Health Sciences Center, Shreveport, Louisiana, USA
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78
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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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79
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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: 73] [Impact Index Per Article: 14.6] [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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80
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Eliyahu E, Tirosh O, Dobesova M, Nachshon A, Schwartz M, Stern-Ginossar N. Rho-Associated Coiled-Coil Kinase 1 Translocates to the Nucleus and Inhibits Human Cytomegalovirus Propagation. J Virol 2019; 93:e00453-19. [PMID: 31292242 PMCID: PMC6744247 DOI: 10.1128/jvi.00453-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 06/29/2019] [Indexed: 01/04/2023] Open
Abstract
Rho-associated coiled-coil kinase (ROCK) protein is a central kinase that regulates numerous cellular functions, including cellular polarity, motility, proliferation, and apoptosis. Here, we demonstrate that ROCK has antiviral properties, and inhibition of its activity results in enhanced propagation of human cytomegalovirus (HCMV). We show that during HCMV infection, ROCK1 translocates to the nucleus and concentrates in the nucleolus, where it colocalizes with the stress-related chaperone heat shock cognate 71-kDa protein (Hsc70). Gene expression measurements show that inhibition of ROCK activity does not seem to affect the cellular stress response. We demonstrate that inhibition of myosin, one of the central targets of ROCK, also increases HCMV propagation, implying that the antiviral activity of ROCK might be mediated by activation of the actomyosin network. Finally, we demonstrate that inhibition of ROCK results in increased levels of the tegument protein UL32 and of viral DNA in the cytoplasm, suggesting ROCK activity hinders the efficient egress of HCMV particles out of the nucleus. Altogether, our findings illustrate ROCK activity restricts HCMV propagation and suggest this inhibitory effect may be mediated by suppression of capsid egress out of the nucleus.IMPORTANCE ROCK is a central kinase in cells that regulates numerous cellular functions, including cellular polarity, motility, proliferation, and apoptosis. Here we reveal a novel antiviral activity of ROCK during infection with HCMV, a prevalent pathogen infecting most of the population worldwide. We reveal ROCK1 is translocated to the nucleus, where it mainly localizes to the nucleolus. Our findings suggest that ROCK's antiviral activity may be related to activation of the actomyosin network and inhibition of capsid egress out of the nucleus.
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Affiliation(s)
- Erez Eliyahu
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Osnat Tirosh
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Martina Dobesova
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Aharon Nachshon
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Michal Schwartz
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Noam Stern-Ginossar
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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81
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van Senten JR, Bebelman MP, Fan TS, Heukers R, Bergkamp ND, van Gasselt P, Langemeijer EV, Slinger E, Lagerweij T, Rahbar A, Stigter-van Walsum M, Maussang D, Leurs R, Musters RJP, van Dongen GAMS, Söderberg-Nauclér C, Würdinger T, Siderius M, Smit MJ. The human cytomegalovirus-encoded G protein-coupled receptor UL33 exhibits oncomodulatory properties. J Biol Chem 2019; 294:16297-16308. [PMID: 31519750 DOI: 10.1074/jbc.ra119.007796] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 09/09/2019] [Indexed: 12/14/2022] Open
Abstract
Herpesviruses can rewire cellular signaling in host cells by expressing viral G protein-coupled receptors (GPCRs). These viral receptors exhibit homology to human chemokine receptors, but some display constitutive activity and promiscuous G protein coupling. Human cytomegalovirus (HCMV) has been detected in multiple cancers, including glioblastoma, and its genome encodes four GPCRs. One of these receptors, US28, is expressed in glioblastoma and possesses constitutive activity and oncomodulatory properties. UL33, another HCMV-encoded GPCR, also displays constitutive signaling via Gαq, Gαi, and Gαs proteins. However, little is known about the nature and functional effects of UL33-driven signaling. Here, we assessed UL33's signaling repertoire and oncomodulatory potential. UL33 activated multiple proliferative, angiogenic, and inflammatory signaling pathways in HEK293T and U251 glioblastoma cells. Notably, upon infection, UL33 contributed to HCMV-mediated STAT3 activation. Moreover, UL33 increased spheroid growth in vitro and accelerated tumor growth in different in vivo tumor models, including an orthotopic glioblastoma xenograft model. UL33-mediated signaling was similar to that stimulated by US28; however, UL33-induced tumor growth was delayed. Additionally, the spatiotemporal expression of the two receptors only partially overlapped in HCMV-infected glioblastoma cells. In conclusion, our results unveil that UL33 has broad signaling capacity and provide mechanistic insight into its functional effects. UL33, like US28, exhibits oncomodulatory properties, elicited via constitutive activation of multiple signaling pathways. UL33 and US28 might contribute to HCMV's oncomodulatory effects through complementing and converging cellular signaling, and hence UL33 may represent a promising drug target in HCMV-associated malignancies.
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Affiliation(s)
- Jeffrey R van Senten
- Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit, 1081 HZ Amsterdam, The Netherlands
| | - Maarten P Bebelman
- Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit, 1081 HZ Amsterdam, The Netherlands
| | - Tian Shu Fan
- Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit, 1081 HZ Amsterdam, The Netherlands
| | - Raimond Heukers
- Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit, 1081 HZ Amsterdam, The Netherlands
| | - Nick D Bergkamp
- Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit, 1081 HZ Amsterdam, The Netherlands
| | - Puck van Gasselt
- Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit, 1081 HZ Amsterdam, The Netherlands
| | - Ellen V Langemeijer
- Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit, 1081 HZ Amsterdam, The Netherlands
| | - Erik Slinger
- Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit, 1081 HZ Amsterdam, The Netherlands
| | - Tonny Lagerweij
- Neuro-oncology Research Group, Cancer Center Amsterdam, VU University Medical Center, 1081 HV Amsterdam, The Netherlands
| | - Afsar Rahbar
- Department of Medicine Solna, Microbial Pathogenesis Research Unit and Department of Neurology, Center for Molecular Medicine, Karolinska Institute, 171 77 Stockholm, Sweden
| | - Marijke Stigter-van Walsum
- Department of Otolaryngology/Head and Neck Surgery, VU University Medical Center, 1081 HV Amsterdam, The Netherlands
| | - David Maussang
- Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit, 1081 HZ Amsterdam, The Netherlands
| | - Rob Leurs
- Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit, 1081 HZ Amsterdam, The Netherlands
| | - René J P Musters
- Department of Physiology, VU University Medical Center, 1081 HV Amsterdam, The Netherlands
| | - Guus A M S van Dongen
- Department of Radiology and Nuclear Medicine, VU University Medical Center, 1081 HV Amsterdam, The Netherlands
| | - Cecilia Söderberg-Nauclér
- Department of Medicine Solna, Microbial Pathogenesis Research Unit and Department of Neurology, Center for Molecular Medicine, Karolinska Institute, 171 77 Stockholm, Sweden
| | - Thomas Würdinger
- Neuro-oncology Research Group, Cancer Center Amsterdam, VU University Medical Center, 1081 HV Amsterdam, The Netherlands
| | - Marco Siderius
- Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit, 1081 HZ Amsterdam, The Netherlands
| | - Martine J Smit
- Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit, 1081 HZ Amsterdam, The Netherlands
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82
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Camacho Ortega SJ, Bohorquez Avila SDP, Velandia Romero ML, Castellanos Parra JE. Isolation of the Human Cytomegalovirus from bodily fluids. ACTA BIOLÓGICA COLOMBIANA 2019. [DOI: 10.15446/abc.v24n3.79406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
In vitro studies on the pathogenesis of the human cytomegalovirus (HCMV) are conducted regularly using laboratory adapted strains that lose some characteristics during the adaptation process. Since HCMV is excreted from bodily fluids during infection or reactivation, this work aimed to isolate and culture HCMV from the MRC-5 human cells found in the urine, bronchoalveolar lavage, saliva, and plasma samples of pediatric patients with probable or confirmed infection. The samples were inoculated on cell cultures either for 14 days or until a cytopathic effect (CPE) of 80 % was observed. The cell lysates and supernatants were used to perform successive viral passages. Besides HCMV, the herpes simplex virus was detected from all the saliva samples. Inoculation of the HCMV positive sera induced cell clustering and immediate monolayer damage that restricted their use. One sample of bronchoalveolar lavage induced a CPE after inoculation like that of the HCMV reference strains (Towne and Merlin), which was consequently propagated and titrated. A second viral isolate derived from the urine sample of a patient with congenital infection did not demonstrate a CPE, although presence of the virus had been confirmed using PCR. The viral isolates were examined and found to be negative for adenoviruses or enteroviruses. Despite the evident difficulty encountered for the isolation and harvesting of the HCMV, this work shows that it was possible to obtain a low passage viral strain using a modified shell vial method and inoculation protocol with extended follow-up and confirmation.
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83
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Dupont L, Du L, Poulter M, Choi S, McIntosh M, Reeves MB. Src family kinase activity drives cytomegalovirus reactivation by recruiting MOZ histone acetyltransferase activity to the viral promoter. J Biol Chem 2019; 294:12901-12910. [PMID: 31273084 PMCID: PMC6721939 DOI: 10.1074/jbc.ra119.009667] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 06/29/2019] [Indexed: 12/25/2022] Open
Abstract
Human cytomegalovirus (HCMV) latency and reactivation rely on a complex interplay between cellular differentiation, cell signaling pathways, and viral gene functions. HCMV reactivation in dendritic cells (DCs) is triggered by IL-6 and extracellular signal-regulated kinase (ERK)-mitogen-activated protein kinase signaling. However, activation of the same pathway fails to reactivate HCMV in other myeloid cell types, despite this signaling axis being active in those cells. We hypothesized that IL-6-induced ERK activation initiates the changes in chromatin structure required for viral reactivation but that a concomitant signal is necessary to complete the changes in chromatin structure required for gene expression to occur. Using a differential phosphoproteomics approach in cells that do or do not support IL-6-induced viral reactivation, we identified the concomitant activation of an Src family kinase (SFK), hematopoietic cell kinase (HCK), specifically in DCs in response to IL-6. Pharmacological and genetic inhibition of HCK activity indicated that HCK is required for HCMV reactivation. Furthermore, the HCK/SFK activity was linked to recruitment of the monocytic leukemia zinc finger protein (MOZ) histone acetyltransferase to the viral promoter, which promoted histone acetylation after ERK-mediated histone phosphorylation. Importantly, pharmacological and genetic inhibition of MOZ activity prevented reactivation. These results provide an explanation for the selective activation of viral gene expression in DCs by IL-6, dependent on concomitant SFK and ERK signaling. They also reveal a previously unreported role for SFK activity in the regulation of chromatin structure at promoters in eukaryotic cells via MOZ histone acetyltransferase activity.
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Affiliation(s)
- Liane Dupont
- Institute of Immunity and Transplantation, Division of Infection and Immunity, Royal Free Hospital, University College London, Hampstead, London NW3 2PF, United Kingdom
| | - Lily Du
- Institute of Immunity and Transplantation, Division of Infection and Immunity, Royal Free Hospital, University College London, Hampstead, London NW3 2PF, United Kingdom
| | - Madeleine Poulter
- Institute of Immunity and Transplantation, Division of Infection and Immunity, Royal Free Hospital, University College London, Hampstead, London NW3 2PF, United Kingdom
| | - Stephanie Choi
- Institute of Immunity and Transplantation, Division of Infection and Immunity, Royal Free Hospital, University College London, Hampstead, London NW3 2PF, United Kingdom
| | - Megan McIntosh
- Institute of Immunity and Transplantation, Division of Infection and Immunity, Royal Free Hospital, University College London, Hampstead, London NW3 2PF, United Kingdom
| | - Matthew B. Reeves
- Institute of Immunity and Transplantation, Division of Infection and Immunity, Royal Free Hospital, University College London, Hampstead, London NW3 2PF, United Kingdom, Supported by Wellcome Trust Grant WT/204870/Z/16/Z. To whom correspondence should be addressed. Tel.:
44-203-1086783; E-mail:
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84
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Patient-Derived Cytomegaloviruses with Different Ganciclovir Sensitivities from UL97 Mutation Retain Their Replication Efficiency and Some Kinase Activity In Vitro. Antimicrob Agents Chemother 2019; 63:AAC.02425-18. [PMID: 31262766 DOI: 10.1128/aac.02425-18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 06/22/2019] [Indexed: 11/20/2022] Open
Abstract
Mutations in the cytomegalovirus UL97 kinase gene contribute to antiviral resistance. Mutations A594S and G598D from two clinical isolates were analyzed, and bacterial artificial chromosome (BAC)-engineered A594S recombinant cytomegalovirus exhibited a ganciclovir-resistant phenotype on plaque reduction. Viral replication was comparable to that of the wild type. Cell-based kinase activity and autophosphorylation of ectopically expressed proteins showed that mutants retained some kinase activity. This study showed that patient-derived cytomegalovirus with different ganciclovir sensitivities retained replication efficiency and exhibited some kinase activity in vitro.
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85
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Gutjahr A, Papagno L, Nicoli F, Kanuma T, Kuse N, Cabral-Piccin MP, Rochereau N, Gostick E, Lioux T, Perouzel E, Price DA, Takiguchi M, Verrier B, Yamamoto T, Paul S, Appay V. The STING ligand cGAMP potentiates the efficacy of vaccine-induced CD8+ T cells. JCI Insight 2019; 4:125107. [PMID: 30944257 DOI: 10.1172/jci.insight.125107] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 02/14/2019] [Indexed: 11/17/2022] Open
Abstract
Pathogen recognition receptor (PRR) agonists are currently being developed and tested as adjuvants in various formulations to optimize the immunogenicity and efficacy of vaccines. Using an original in vitro approach to prime naive precursors from unfractionated human peripheral blood mononuclear cells, we assessed the influence of cyclic guanosine monophosphate-adenosine monophosphate (cGAMP), a ligand for the stimulator of interferon genes (STING), on the induction of antigen-specific CD8+ T cells. We found that 2'3'-cGAMP and 3'3'-cGAMP were especially potent adjuvants in this system, driving the expansion and maturation of functionally replete antigen-specific CD8+ T cells via the induction of type I IFNs. The biological relevance of these findings was confirmed in vivo using two mouse models, in which 2'3'-cGAMP-adjuvanted vaccination elicited protective antitumor or antiviral CD8+ T cell responses. These results identify particular isoforms of cGAMP as effective adjuvants that may find utility in the development of novel immunotherapies and vaccines.
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Affiliation(s)
- Alice Gutjahr
- Groupe Immunité des Muqueuses et Agents Pathogènes, INSERM, Centre d'Investigation Clinique en Vaccinologie 1408, Faculté de Médecine de Saint-Etienne, Saint-Etienne, France.,Laboratoire de Biologie Tissulaire et d'Ingénierie Thérapeutique, Unité Mixte de Recherche 5305, Université Lyon 1, CNRS, Lyon, France.,InvivoGen, Toulouse, France
| | - Laura Papagno
- Sorbonne Université, INSERM, Centre d'Immunologie et des Maladies Infectieuses (CIMI-Paris), Paris, France
| | - Francesco Nicoli
- Sorbonne Université, INSERM, Centre d'Immunologie et des Maladies Infectieuses (CIMI-Paris), Paris, France
| | - Tomohiro Kanuma
- Laboratory of Immunosenescence, National Institutes of Biomedical Innovation, Health and Nutrition, Osaka, Japan
| | - Nozomi Kuse
- Center for AIDS Research, Kumamoto University, Kumamoto, Japan
| | | | | | - Emma Gostick
- Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff, United Kingdom
| | | | | | - David A Price
- Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff, United Kingdom
| | | | - Bernard Verrier
- Laboratoire de Biologie Tissulaire et d'Ingénierie Thérapeutique, Unité Mixte de Recherche 5305, Université Lyon 1, CNRS, Lyon, France
| | - Takuya Yamamoto
- Laboratory of Immunosenescence, National Institutes of Biomedical Innovation, Health and Nutrition, Osaka, Japan.,Center for AIDS Research, Kumamoto University, Kumamoto, Japan
| | - Stéphane Paul
- Groupe Immunité des Muqueuses et Agents Pathogènes, INSERM, Centre d'Investigation Clinique en Vaccinologie 1408, Faculté de Médecine de Saint-Etienne, Saint-Etienne, France
| | - Victor Appay
- Sorbonne Université, INSERM, Centre d'Immunologie et des Maladies Infectieuses (CIMI-Paris), Paris, France.,International Research Center of Medical Sciences (IRCMS), Kumamoto University, Kumamoto, Japan
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86
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Ashley CL, Abendroth A, McSharry BP, Slobedman B. Interferon-Independent Upregulation of Interferon-Stimulated Genes during Human Cytomegalovirus Infection is Dependent on IRF3 Expression. Viruses 2019; 11:E246. [PMID: 30871003 PMCID: PMC6466086 DOI: 10.3390/v11030246] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 02/25/2019] [Accepted: 03/07/2019] [Indexed: 12/25/2022] Open
Abstract
The antiviral activity of type I interferons (IFNs) is primarily mediated by interferon-stimulated genes (ISGs). Induction of ISG transcription is achieved when type I IFNs bind to their cognate receptor and activate the Janus Kinase/Signal Transducer and Activator of Transcription (JAK/STAT) signaling pathways. Recently it has become clear that a number of viruses are capable of directly upregulating a subset of ISGs in the absence of type I IFN production. Using cells engineered to block either the response to, or production of type I IFN, the regulation of IFN-independent ISGs was examined in the context of human cytomegalovirus (HCMV) infection. Several ISGs, including IFIT1, IFIT2, IFIT3, Mx1, Mx2, CXCL10 and ISG15 were found to be upregulated transcriptionally following HCMV infection independently of type I IFN-initiated JAK-STAT signaling, but dependent on intact IRF3 signaling. ISG15 protein regulation mirrored that of its transcript with IFNβ neutralization failing to completely inhibit ISG15 expression post HCMV infection. In addition, no detectable ISG15 protein expression was observed following HCMV infection in IRF3 knockdown CRISPR/Cas-9 clones indicating that IFN-independent control of ISG expression during HCMV infection of human fibroblasts is absolutely dependent on IRF3 expression.
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Affiliation(s)
- Caroline L Ashley
- Department of Infectious Diseases and Immunology, Charles Perkins Centre, University of Sydney, Camperdown, New South Wales 2050, Australia.
| | - Allison Abendroth
- Department of Infectious Diseases and Immunology, Charles Perkins Centre, University of Sydney, Camperdown, New South Wales 2050, Australia.
| | - Brian P McSharry
- Department of Infectious Diseases and Immunology, Charles Perkins Centre, University of Sydney, Camperdown, New South Wales 2050, Australia.
| | - Barry Slobedman
- Department of Infectious Diseases and Immunology, Charles Perkins Centre, University of Sydney, Camperdown, New South Wales 2050, Australia.
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87
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Inclusion of Antibodies to Cell Culture Media Preserves the Integrity of Genes Encoding RL13 and the Pentameric Complex Components During Fibroblast Passage of Human Cytomegalovirus. Viruses 2019; 11:v11030221. [PMID: 30841507 PMCID: PMC6466449 DOI: 10.3390/v11030221] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 02/16/2019] [Indexed: 12/11/2022] Open
Abstract
Propagation of human cytomegalovirus (CMV) in cultured cells results in genetic adaptations that confer improved growth in vitro and significant attenuation in vivo. Mutations in RL13 arise quickly, while mutations in the UL128-131A locus emerge later during fibroblast passage and disrupt formation of a glycoprotein complex that is important for entry into epithelial and endothelial cells. As CMV replicates in the context of host antibodies in vivo, we reasoned that antibodies might mitigate the accumulation of adaptive mutations during cell culture passage. To test this, CMV in infant urine was used to infect replicate fibroblast cultures. One lineage was passaged in the absence of CMV-hyperimmuneglobulin (HIG) while the other was passaged with HIG in the culture medium. The former lost epithelial tropism and acquired mutations disrupting RL13 and UL131A expression, whereas the latter retained epithelial tropism and both gene loci remained intact after 22 passages. Additional mutations resulting in single amino acid changes also occurred in UL100 encoding glycoprotein M, UL102 encoding a subunit of the helicase/primase complex, and UL122 encoding the Immediate Early 2 protein. An epitheliotropic RL13+/UL131A+ virus was isolated by limiting dilution in the presence of HIG and expanded to produce a working stock sufficient to conduct cell tropism experiments. Thus, production of virus stocks by culture in the presence of antibodies may facilitate in vitro experiments using viruses that are genetically more authentic than previously available.
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88
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Copy-Paste Mutagenesis: A Method for Large-Scale Alteration of Viral Genomes. Int J Mol Sci 2019; 20:ijms20040913. [PMID: 30791544 PMCID: PMC6413233 DOI: 10.3390/ijms20040913] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 02/14/2019] [Accepted: 02/15/2019] [Indexed: 12/19/2022] Open
Abstract
The cloning of the large DNA genomes of herpesviruses, poxviruses, and baculoviruses as bacterial artificial chromosomes (BAC) in Escherichia coli has opened a new era in viral genetics. Several methods of lambda Red-mediated genome engineering (recombineering) in E. coli have been described, which are now commonly used to generate recombinant viral genomes. These methods are very efficient at introducing deletions, small insertions, and point mutations. Here we present Copy-Paste mutagenesis, an efficient and versatile strategy for scarless large-scale alteration of viral genomes. It combines gap repair and en passant mutagenesis procedures and relies on positive selection in all crucial steps. We demonstrate that this method can be used to generate chimeric strains of human cytomegalovirus (HCMV), the largest human DNA virus. Large (~15 kbp) genome fragments of HCMV strain TB40/E were tagged with an excisable marker and cloned (copied) in a low-copy plasmid vector by gap repair recombination. The cloned fragment was then excised and inserted (pasted) into the HCMV AD169 genome with subsequent scarless removal of the marker by en passant mutagenesis. We have done four consecutive rounds of this procedure, thereby generating an AD169-TB40/E chimera containing 60 kbp of the donor strain TB40/E. This procedure is highly useful for identifying gene variants responsible for phenotypic differences between viral strains. It can also be used for repair of incomplete viral genomes, and for modification of any BAC-cloned sequence. The method should also be applicable for large-scale alterations of bacterial genomes.
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89
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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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90
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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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91
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Hamilton ST, Hutterer C, Egilmezer E, Steingruber M, Milbradt J, Marschall M, Rawlinson WD. Human cytomegalovirus utilises cellular dual-specificity tyrosine phosphorylation-regulated kinases during placental replication. Placenta 2018; 72-73:10-19. [PMID: 30501876 DOI: 10.1016/j.placenta.2018.10.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Revised: 09/28/2018] [Accepted: 10/12/2018] [Indexed: 01/02/2023]
Abstract
INTRODUCTION Congenital cytomegalovirus (HCMV) infection may cause significant fetal malformation and in severe cases fetal and neonatal death. Fetal injury may be caused indirectly by the placental response to infection. Dual-specificity tyrosine phosphorylation-regulated kinases (DYRKs) have recently been identified as critical kinases for HCMV replication. In this study we provide first evidence that DYRK1A and DYRK1B are utilised during HCMV placental replication. METHODS DYRK expression was investigated in AD169- and Merlin-infected TEV-1 trophoblast cells, ex vivo placental explants and naturally infected clinical placentae by immunofluorescence, western blot, co-immunoprecipitation and RT-qPCR. RESULTS HCMV-infected placental cells showed accumulation and re-localisation of DYRK1A and DYRK1B protein to areas of cytoplasmic virion assembly complexes and nuclear viral replication compartments, respectively. This accumulation was a result of upregulated DYRK1A/B protein expression with HCMV inducing up to a 5.3-fold increase in DYRK1A and up to a 4.7-fold increase in DYRK1B protein, relative to mock-infected TEV-1 cells (p < 0.0001). Increased DYRK protein expression was correlated with DYRK1A/B mRNA upregulation, with HCMV-infected cells showing up to a 3.7-fold increase and 2.9-fold increase in DYRK1A and DYRK1B mRNA levels respectively (p < 0.05). Protein-protein interactions were detected between DYRK1A/1B complexes and HCMV immediate early IE2p86, early pp65 and pUL44 and late pp150 proteins. Treatment of HCMV-infected TEV-1 cells and placental explants with DYRK inhibitors significantly inhibited HCMV replication (p < 0.05) indicating these cellular kinases are required during HCMV placental replication. CONCLUSION HCMV modulates cellular DYRKs during placental replication which may have implications for congenital HCMV pathogenesis and represent promising antiviral targets.
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Affiliation(s)
- Stuart T Hamilton
- Serology and Virology Division, SEALS Microbiology, Prince of Wales Hospital, Sydney, Australia; School of Women's and Children's Health, University of New South Wales, Australia
| | - Corina Hutterer
- Institute for Clinical and Molecular Virology, Friedrich-Alexander University of Erlangen-Nürnberg (FAU), Germany
| | - Ece Egilmezer
- Serology and Virology Division, SEALS Microbiology, Prince of Wales Hospital, Sydney, Australia; School of Medical Sciences, University of New South Wales, Australia
| | - Mirjam Steingruber
- Institute for Clinical and Molecular Virology, Friedrich-Alexander University of Erlangen-Nürnberg (FAU), Germany
| | - Jens Milbradt
- Institute for Clinical and Molecular Virology, Friedrich-Alexander University of Erlangen-Nürnberg (FAU), Germany
| | - Manfred Marschall
- Institute for Clinical and Molecular Virology, Friedrich-Alexander University of Erlangen-Nürnberg (FAU), Germany
| | - William D Rawlinson
- Serology and Virology Division, SEALS Microbiology, Prince of Wales Hospital, Sydney, Australia; School of Women's and Children's Health, University of New South Wales, Australia; School of Medical Sciences, University of New South Wales, Australia; School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia.
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92
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Wu K, Oberstein A, Wang W, Shenk T. Role of PDGF receptor-α during human cytomegalovirus entry into fibroblasts. Proc Natl Acad Sci U S A 2018; 115:E9889-E9898. [PMID: 30275317 PMCID: PMC6196492 DOI: 10.1073/pnas.1806305115] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Human CMV (HCMV) exhibits a broad cell tropism that depends on two virion glycoprotein complexes: a trimeric complex (gH/gL/gO) that facilitates viral infection primarily in fibroblasts and a pentameric complex (gH/gL/pUL128-pUL130-pUL131A) that mediates infection in epithelial and endothelial cells. We performed genome-wide CRISPR screens in which the PDGF receptor-α (PDGFRα) was identified as the most significant cellular gene product essential for infection by HCMV virions containing only trimeric complex (trimer-only virus). Trimer-only virus did not enter PDGFRα knockout fibroblasts. By using knockout fibroblasts, the extracellular domain of PDGFRα required for virus entry was mapped, and the intracellular tyrosine kinase domain was shown to be nonessential. In addition, direct cell-to-cell spread of virus from knockout cells transfected with trimer-only viral DNA was blocked, despite the production of infectious virus in the transfected cells. In contrast to trimer-only virus, wild-type HCMV virions containing both trimeric and pentameric complexes entered PDGFRα knockout cells, reinforcing the view that fibroblasts contain a second, independent receptor for the pentameric complex. Importantly, however, wild-type virus entered the knockout fibroblasts at reduced efficiency compared with parental fibroblasts, arguing that the cellular receptor for the virion pentameric complex is limiting or that virions are produced containing different relative amounts of the two glycoprotein complexes. Finally, ectopic expression of PDGFRα in ARPE-19 epithelial cells and THP-1 monocytic cells, which have little to no endogenous PDGFRα expression, markedly enhanced their susceptibility to trimer-only virions. In sum, our data clarify several key determinants of HCMV tropism.
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Affiliation(s)
- Kai Wu
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544
| | - Adam Oberstein
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544
| | - Wei Wang
- Genomics Core Facility, Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544
| | - Thomas Shenk
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544;
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93
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Mizrahi O, Nachshon A, Shitrit A, Gelbart IA, Dobesova M, Brenner S, Kahana C, Stern-Ginossar N. Virus-Induced Changes in mRNA Secondary Structure Uncover cis-Regulatory Elements that Directly Control Gene Expression. Mol Cell 2018; 72:862-874.e5. [PMID: 30318442 DOI: 10.1016/j.molcel.2018.09.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 07/16/2018] [Accepted: 08/31/2018] [Indexed: 11/25/2022]
Abstract
mRNAs carry two layers of information, the genetic code and the information that dictates their post-transcriptional fate. The latter function relies on a complex interplay between cis-elements and trans-regulators, and unbiased identification of these elements is still challenging. To identify cis-elements that control gene expression, we use dimethyl sulfate (DMS) mutational profiling with sequencing and map changes in mRNA secondary structure following viral infection. Our dynamic structural data reveal a major role for ribosomes in unwinding secondary structures, which is further supported by the relationship we uncover between structure and translation efficiency. Moreover, our analysis revealed dozens of regions in viral and cellular mRNAs that exhibit changes in secondary structure. In-depth analysis of these regions reveals cis-elements in 3' UTRs that regulate mRNA stability and elements within coding sequences that control translation. Overall, our study demonstrates how mapping dynamic changes in mRNA structure allows unbiased identification of functional regulatory elements.
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Affiliation(s)
- Orel Mizrahi
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Aharon Nachshon
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Alina Shitrit
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Idit A Gelbart
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Martina Dobesova
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Shirly Brenner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Chaim Kahana
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Noam Stern-Ginossar
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel.
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94
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Patel M, Vlahava VM, Forbes SK, Fielding CA, Stanton RJ, Wang ECY. HCMV-Encoded NK Modulators: Lessons From in vitro and in vivo Genetic Variation. Front Immunol 2018; 9:2214. [PMID: 30327650 PMCID: PMC6174198 DOI: 10.3389/fimmu.2018.02214] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Accepted: 09/06/2018] [Indexed: 12/22/2022] Open
Abstract
Human cytomegalovirus (HCMV) is under constant selective pressure from the immune system in vivo. Study of HCMV genes that have been lost in the absence of, or genetically altered by, such selection can focus research toward findings of in vivo significance. We have been particularly interested in the most pronounced change in the highly passaged laboratory strains AD169 and Towne—the deletion of 13–15 kb of sequence (designated the UL/b′ region) that encodes up to 22 canonical genes, UL133-UL150. At least 5 genes have been identified in UL/b′ that inhibit NK cell function. UL135 suppresses formation of the immunological synapse (IS) by remodeling the actin cytoskeleton, thereby illustrating target cell cooperation in IS formation. UL141 inhibits expression of two activating ligands (CD155, CD112) for the activating receptor CD226 (DNAM-1), and two receptors (TRAIL-R1, R2) for the apoptosis-inducing TRAIL. UL142, ectopically expressed in isolation, and UL148A, target specific MICA allotypes that are ligands for NKG2D. UL148 impairs expression of CD58 (LFA-3), the co-stimulatory cell adhesion molecule for CD2 found on T and NK cells. Outside UL/b′, studies on natural variants have shown UL18 mutants change affinity for their inhibitory ligand LIR-1, while mutations in UL40's HLA-E binding peptide differentially drive NKG2C+ NK expansions. Research into HCMV genomic stability and its effect on NK function has provided important insights into virus:host interactions, but future studies will require consideration of genetic variability and the effect of genes expressed in the context of infection to fully understand their in vivo impact.
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Affiliation(s)
- Mihil Patel
- Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Virginia-Maria Vlahava
- Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Simone K Forbes
- Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Ceri A Fielding
- Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Richard J Stanton
- Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Eddie C Y Wang
- Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff, United Kingdom
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95
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Large-Scale Screening of HCMV-Seropositive Blood Donors Indicates that HCMV Effectively Escapes from Antibodies by Cell-Associated Spread. Viruses 2018; 10:v10090500. [PMID: 30223489 PMCID: PMC6163834 DOI: 10.3390/v10090500] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 09/07/2018] [Accepted: 09/12/2018] [Indexed: 12/16/2022] Open
Abstract
Immunoglobulins are only moderately effective for the treatment of human cytomegalovirus (HCMV) infections, possibly due to ineffectiveness against cell-associated virus spread. To overcome this limitation, we aimed to identify individuals with exceptional antibodies in their plasma that can efficiently block the cell-associated spread of HCMV. A Gaussia luciferase-secreting mutant of the cell-associated HCMV strain Merlin was generated, and luciferase activity evaluated as a readout for the extent of cell-associated focal spread. This reporter virus-based assay was then applied to screen plasma samples from 8400 HCMV-seropositive individuals for their inhibitory effect, including direct-acting antiviral drugs as positive controls. None of the plasmas reduced virus spread to the level of these controls. Even the top-scoring samples that partially reduced luciferase activity in the screening assay failed to inhibit focal growth when reevaluated with a more accurate, immunofluorescence-based assay. Selected sera with high neutralizing capacity against free viruses were analyzed separately, and none of them prevented the focal spread of three recent clinical HCMV isolates nor reduced the number of particles transmitted, as demonstrated with a fluorescent Merlin mutant. We concluded that donors with cell-to-cell-spread-inhibiting plasma are nonexistent or extremely rare, emphasizing cell-associated spread as a highly efficient immune escape mechanism of HCMV.
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96
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Human Cytomegalovirus Tropism Modulator UL148 Interacts with SEL1L, a Cellular Factor That Governs Endoplasmic Reticulum-Associated Degradation of the Viral Envelope Glycoprotein gO. J Virol 2018; 92:JVI.00688-18. [PMID: 29997207 DOI: 10.1128/jvi.00688-18] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 06/29/2018] [Indexed: 11/20/2022] Open
Abstract
UL148 is a viral endoplasmic reticulum (ER)-resident glycoprotein that contributes to human cytomegalovirus (HCMV) cell tropism. The influence of UL148 on tropism correlates with its potential to promote the expression of glycoprotein O (gO), a viral envelope glycoprotein that participates in a heterotrimeric complex with glycoproteins H and L that is required for infectivity. In an effort to gain insight into the mechanism, we used mass spectrometry to identify proteins that coimmunoprecipitate from infected cells with UL148. This approach led us to identify an interaction between UL148 and SEL1L, a factor that plays key roles in ER-associated degradation (ERAD). In pulse-chase experiments, gO was less stable in cells infected with UL148-null mutant HCMV than during wild-type infection, suggesting a potential functional relevance for the interaction with SEL1L. To investigate whether UL148 regulates gO abundance by influencing ERAD, small interfering RNA (siRNA) silencing of either SEL1L or its partner, Hrd1, was carried out in the context of infection. Knockdown of these ERAD factors strongly enhanced levels of gO but not other viral glycoproteins, and the effect was amplified in the presence of UL148. Furthermore, pharmacological inhibition of ERAD showed similar results. Silencing of SEL1L during infection also stabilized an interaction of gO with the ER lectin OS-9, which likewise suggests that gO is an ERAD substrate. Taken together, our results identify an intriguing interaction of UL148 with the ERAD machinery and demonstrate that gO behaves as a constitutive ERAD substrate during infection. These findings have implications for understanding the regulation of HCMV cell tropism.IMPORTANCE Viral glycoproteins in large part determine the cell types that an enveloped virus can infect and hence play crucial roles in transmission and pathogenesis. The glycoprotein H/L heterodimer (gH/gL) is part of the conserved membrane fusion machinery that all herpesviruses use to enter cells. In human cytomegalovirus (HCMV), gH/gL participates in alternative complexes in virions, one of which is a trimer of gH/gL with glycoprotein O (gO). Here, we show that gO is constitutively degraded during infection by the endoplasmic reticulum-associated degradation (ERAD) pathway and that UL148, a viral factor that regulates HCMV cell tropism, interacts with the ERAD machinery and slows gO decay. Since gO is required for cell-free virus to enter new host cells but dispensable for cell-associated spread that resists antibody neutralization, our findings imply that the posttranslational instability of a viral glycoprotein provides a basis for viral mechanisms to modulate tropism and spread.
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97
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Nightingale K, Lin KM, Ravenhill BJ, Davies C, Nobre L, Fielding CA, Ruckova E, Fletcher-Etherington A, Soday L, Nichols H, Sugrue D, Wang ECY, Moreno P, Umrania Y, Huttlin EL, Antrobus R, Davison AJ, Wilkinson GWG, Stanton RJ, Tomasec P, Weekes MP. High-Definition Analysis of Host Protein Stability during Human Cytomegalovirus Infection Reveals Antiviral Factors and Viral Evasion Mechanisms. Cell Host Microbe 2018; 24:447-460.e11. [PMID: 30122656 PMCID: PMC6146656 DOI: 10.1016/j.chom.2018.07.011] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 06/01/2018] [Accepted: 06/25/2018] [Indexed: 12/03/2022]
Abstract
Human cytomegalovirus (HCMV) is an important pathogen with multiple immune evasion strategies, including virally facilitated degradation of host antiviral restriction factors. Here, we describe a multiplexed approach to discover proteins with innate immune function on the basis of active degradation by the proteasome or lysosome during early-phase HCMV infection. Using three orthogonal proteomic/transcriptomic screens to quantify protein degradation, with high confidence we identified 35 proteins enriched in antiviral restriction factors. A final screen employed a comprehensive panel of viral mutants to predict viral genes that target >250 human proteins. This approach revealed that helicase-like transcription factor (HLTF), a DNA helicase important in DNA repair, potently inhibits early viral gene expression but is rapidly degraded during infection. The functionally unknown HCMV protein UL145 facilitates HLTF degradation by recruiting the Cullin4 E3 ligase complex. Our approach and data will enable further identifications of innate pathways targeted by HCMV and other viruses. Multiplexed viral screens uncover host proteins targeted by early HCMV infection Finding host proteins targeted for degradation by HCMV reveals immune evasion strategies A screen of HCMV deletion mutants discovers viral factors that target >250 host proteins HLTF is an antiviral restriction factor that is targeted for degradation by HCMV UL145
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Affiliation(s)
- Katie Nightingale
- Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Kai-Min Lin
- Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Benjamin J Ravenhill
- Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Colin Davies
- Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Luis Nobre
- Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Ceri A Fielding
- Cardiff University School of Medicine, Division of Infection and Immunity, Henry Wellcome Building, Heath Park, Cardiff CF14 4XN, UK
| | - Eva Ruckova
- Regional Centre for Applied Molecular Oncology (RECAMO), Masaryk Memorial Cancer Institute, Zluty Kopec 7, 65653 Brno, Czech Republic
| | | | - Lior Soday
- Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Hester Nichols
- Cardiff University School of Medicine, Division of Infection and Immunity, Henry Wellcome Building, Heath Park, Cardiff CF14 4XN, UK
| | - Daniel Sugrue
- Cardiff University School of Medicine, Division of Infection and Immunity, Henry Wellcome Building, Heath Park, Cardiff CF14 4XN, UK
| | - Eddie C Y Wang
- Cardiff University School of Medicine, Division of Infection and Immunity, Henry Wellcome Building, Heath Park, Cardiff CF14 4XN, UK
| | - Pablo Moreno
- Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Yagnesh Umrania
- Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Edward L Huttlin
- Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
| | - Robin Antrobus
- Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Andrew J Davison
- MRC-University of Glasgow Centre for Virus Research, Sir Michael Stoker Building, 464 Bearsden Road, Glasgow G61 1QH, UK
| | - Gavin W G Wilkinson
- Cardiff University School of Medicine, Division of Infection and Immunity, Henry Wellcome Building, Heath Park, Cardiff CF14 4XN, UK
| | - Richard J Stanton
- Cardiff University School of Medicine, Division of Infection and Immunity, Henry Wellcome Building, Heath Park, Cardiff CF14 4XN, UK
| | - Peter Tomasec
- Cardiff University School of Medicine, Division of Infection and Immunity, Henry Wellcome Building, Heath Park, Cardiff CF14 4XN, UK
| | - Michael P Weekes
- Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK.
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98
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Strang BL, Asquith CRM, Moshrif HF, Ho CMK, Zuercher WJ, Al-Ali H. Identification of lead anti-human cytomegalovirus compounds targeting MAP4K4 via machine learning analysis of kinase inhibitor screening data. PLoS One 2018; 13:e0201321. [PMID: 30048526 PMCID: PMC6062112 DOI: 10.1371/journal.pone.0201321] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 07/12/2018] [Indexed: 01/29/2023] Open
Abstract
Chemogenomic approaches involving highly annotated compound sets and cell based high throughput screening are emerging as a means to identify novel drug targets. We have previously screened a collection of highly characterized kinase inhibitors (Khan et al., Journal of General Virology, 2016) to identify compounds that increase or decrease expression of a human cytomegalovirus (HCMV) protein in infected cells. To identify potential novel anti-HCMV drug targets we used a machine learning approach to relate our phenotypic data from the aforementioned screen to kinase inhibition profiling of compounds used in this screen. Several of the potential targets had no previously reported role in HCMV replication. We focused on one potential anti-HCMV target, MAPK4K, and identified lead compounds inhibiting MAP4K4 that have anti-HCMV activity with little cellular cytotoxicity. We found that treatment of HCMV infected cells with inhibitors of MAP4K4, or an siRNA that inhibited MAP4K4 production, reduced HCMV replication and impaired detection of IE2-60, a viral protein necessary for efficient HCMV replication. Our findings demonstrate the potential of this machine learning approach to identify novel anti-viral drug targets, which can inform the discovery of novel anti-viral lead compounds.
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Affiliation(s)
- Blair L. Strang
- Institute for Infection & Immunity, St George’s, University of London, London, United Kingdom
| | - Christopher R. M. Asquith
- Structural Genomics Consortium, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Hanan F. Moshrif
- Institute for Infection & Immunity, St George’s, University of London, London, United Kingdom
| | - Catherine M-K Ho
- Institute for Infection & Immunity, St George’s, University of London, London, United Kingdom
| | - William J. Zuercher
- Structural Genomics Consortium, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Hassan Al-Ali
- Miami Project to Cure Paralysis, University of Miami, Miami, Florida, United States of America
- Department of Neurological Surgery, University of Miami, Miami, Florida, United States of America
- Sylvester Comprehensive Cancer Center, University of Miami, Miami, Florida, United States of America
- Katz Drug Discovery Center, University of Miami, Miami, Florida, United States of America
- Department of Medicine, University of Miami, Miami, Florida, United States of America
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99
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Expression Levels of Glycoprotein O (gO) Vary between Strains of Human Cytomegalovirus, Influencing the Assembly of gH/gL Complexes and Virion Infectivity. J Virol 2018; 92:JVI.00606-18. [PMID: 29743375 DOI: 10.1128/jvi.00606-18] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 05/02/2018] [Indexed: 12/13/2022] Open
Abstract
The tropism of human cytomegalovirus (HCMV) is influenced by the envelope glycoprotein complexes gH/gL/gO and gH/gL/UL128-131. During virion assembly, gO and the UL128-131 proteins compete for binding to gH/gL in the endoplasmic reticulum (ER). This assembly process clearly differs among strains, since Merlin (ME) virions contain abundant gH/gL/UL128-131 and little gH/gL/gO, whereas TR contains much higher levels of total gH/gL, mostly in the form of gH/gL/gO, but much lower levels of gH/gL/UL128-131 than ME. Remaining questions include (i) what are the mechanisms behind these assembly differences, and (ii) do differences reflect in vitro culture adaptations or natural genetic variations? Since the UL74(gO) open reading frame (ORF) differs in 25% of amino acids between TR and ME, we analyzed recombinant viruses in which the UL74(gO) ORF was swapped. TR virions were >40-fold more infectious than ME. Transcriptional repression of UL128-131 enhanced the infectivity of ME to the level of TR, despite still far lower levels of gH/gL/gO. Swapping the UL74(gO) ORF had no effect on either TR or ME. A quantitative immunoprecipitation approach revealed that gH/gL expression levels were within 4-fold between TR and ME, but the gO expression level was 20-fold lower for ME, which suggested differences in mRNA transcription, translation, or rapid ER-associated degradation of gO. trans-Complementation of gO expression during ME replication gave a 6-fold enhancement of infectivity beyond the 40-fold effect of UL128-131 repression alone. Overall, strain variations in the assembly of gH/gL complexes result from differences in the expression of gO and UL128-131, and selective advantages for reduced UL128-131 expression during fibroblast propagation are much stronger than those for higher gO expression.IMPORTANCE Specific genetic differences between independently isolated HCMV strains may result from purifying selection on de novo mutations arising during propagation in culture or random sampling among the diversity of genotypes present in clinical specimens. Results presented indicate that while reduced UL128-131 expression may confer a powerful selective advantage during cell-free propagation of HCMV in fibroblast cultures, selective pressures for increased gO expression are much weaker. Thus, variation in gO expression among independent strains may represent natural genotype variability present in vivo This may have important implications for virus-host interactions, such as immune recognition, and underscores the value of studying molecular mechanisms of replication using multiple HCMV strains.
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100
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Poole EL, Kew VG, Lau JC, Murray MJ, Stamminger T, Sinclair JH, Reeves MB. A Virally Encoded DeSUMOylase Activity Is Required for Cytomegalovirus Reactivation from Latency. Cell Rep 2018; 24:594-606. [PMID: 30021158 PMCID: PMC6077246 DOI: 10.1016/j.celrep.2018.06.048] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 05/03/2018] [Accepted: 06/11/2018] [Indexed: 02/02/2023] Open
Abstract
A subset of viral genes is required for the long-term latent infection of hematopoietic cells by human cytomegalovirus (HCMV). Here, we show that a latency-associated gene product (LUNA) promotes the disruption of cellular PML bodies during latency. Mutation and inhibitor studies reveal that LUNA encodes a deSUMOylase activity responsible for this disruption. Specifically, LUNA encodes a conserved Asp-Cys-Gly motif common to all deSUMOylases. Importantly, mutation of the putative catalytic cysteine is sufficient to reverse LUNA-mediated PML dispersal and markedly reduces the efficiency of viral reactivation. The depletion of PML from cells is sufficient to rescue the reactivation of the LUNA-deficient viruses, arguing that targeting PML is an important biological role of LUNA. Finally, we demonstrate that reactivation of naturally latent HCMV is blocked by deSUMOylase inhibitors. Thus, latent HCMV primes the cellular environment for efficient reactivation via the activity of a virally encoded deSUMOylase.
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Affiliation(s)
- Emma L. Poole
- Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Cambridge CB2 2QQ, UK
| | - Verity G. Kew
- Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Cambridge CB2 2QQ, UK
| | - Jonathan C.H. Lau
- Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Cambridge CB2 2QQ, UK
| | - Matthew J. Murray
- Institute of Immunity & Transplantation, University College London, Royal Free Campus, London NW3 2PF, UK
| | | | - John H. Sinclair
- Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Cambridge CB2 2QQ, UK,Corresponding author
| | - Matthew B. Reeves
- Institute of Immunity & Transplantation, University College London, Royal Free Campus, London NW3 2PF, UK,Corresponding author
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