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Hofstadter WA, Park JW, Lum KK, Chen S, Cristea IM. HCMV strain- and cell type-specific alterations in membrane contact sites point to the convergent regulation of organelle remodeling. J Virol 2024; 98:e0109924. [PMID: 39480111 PMCID: PMC11575408 DOI: 10.1128/jvi.01099-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2024] [Accepted: 10/09/2024] [Indexed: 11/02/2024] Open
Abstract
Viruses are ubiquitous entities that infect organisms across the kingdoms of life. While viruses can infect a range of cells, tissues, and organisms, this aspect is often not explored in cell culture analyses. There is limited information about which infection-induced changes are shared or distinct in different cellular environments. The prevalent pathogen human cytomegalovirus (HCMV) remodels the structure and function of subcellular organelles and their interconnected networks formed by membrane contact sites (MCSs). A large portion of this knowledge has been derived from fibroblasts infected with a lab-adapted HCMV strain. Here, we assess strain- and cell type-specific alterations in MCSs and organelle remodeling induced by HCMV. Integrating quantitative mass spectrometry, super-resolution microscopy, and molecular virology assays, we compare infections with lab-adapted and low-passage HCMV strains in fibroblast and epithelial cells. We determine that, despite baseline proteome disparities between uninfected fibroblast and epithelial cells, infection induces convergent changes and is remarkably similar. We show that hallmarks of HCMV infection in fibroblasts, mitochondria-endoplasmic reticulum (ER) encapsulations and peroxisome proliferation, are also conserved in infected epithelial and macrophage-like cells. Exploring cell type-specific differences, we demonstrate that fibroblasts rely on endosomal cholesterol transport while epithelial cells rely on cholesterol from the Golgi. Despite these mechanistic differences, infections in both cell types result in phenotypically similar cholesterol accumulation at the viral assembly complex. Our findings highlight the adaptability of HCMV, in that infections can be tailored to the initial cell state by inducing both shared and unique proteome alterations, ultimately promoting a unified pro-viral environment.IMPORTANCEHuman cytomegalovirus (HCMV) establishes infections in diverse cell types throughout the body and is connected to a litany of diseases associated with each of these tissues. However, it is still not fully understood how HCMV replication varies in distinct cell types. Here, we compare HCMV replication with lab-adapted and low-passage strains in two primary sites of infection, lung fibroblasts and retinal epithelial cells. We discover that, despite displaying disparate protein compositions prior to infection, these cell types undergo convergent alterations upon HCMV infection, reaching a more similar cellular state late in infection. We find that remodeling of the subcellular landscape is a pervasive feature of HCMV infection, through alterations to both organelle structure-function and the interconnected networks they form via membrane contact sites. Our findings show how HCMV infection in different cell types induces both shared and divergent changes to cellular processes, ultimately leading to a more unified state.
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Affiliation(s)
- William A Hofstadter
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Ji Woo Park
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Krystal K Lum
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Sophia Chen
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Ileana M Cristea
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
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2
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Ohman MS, Albright ER, Gelbmann CB, Kalejta RF. The Pentamer glycoprotein complex inhibits viral Immediate Early transcription during Human Cytomegalovirus infections. Proc Natl Acad Sci U S A 2024; 121:e2408078121. [PMID: 39292744 PMCID: PMC11441559 DOI: 10.1073/pnas.2408078121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Accepted: 08/16/2024] [Indexed: 09/20/2024] Open
Abstract
The Pentamer complex of Human Cytomegalovirus (HCMV) consists of the viral glycoproteins gH, gL, UL128, UL130, and UL131 and is incorporated into infectious virions. HCMV strains propagated extensively in vitro in fibroblasts carry UL128, UL130, or UL131 alleles that do not make a functional complex and thus lack Pentamer function. Adding functional Pentamer to such strains decreases virus growth in fibroblasts. Here, we show that the Pentamer inhibits productive HCMV replication in fibroblasts by repressing viral Immediate Early (IE) transcription. We show that ectopic expression of the viral IE1 protein, a target of Pentamer-mediated transcriptional repression, complements the growth defect of a Pentamer-positive virus. Furthermore, we show that the Pentamer also represses viral IE transcription in cell types where HCMV in vitro latency is studied. Finally, we identify UL130 as a functional subunit of the Pentamer for IE transcriptional repression and demonstrate that cyclic AMP Response Element (CRE) and NFkB sites within the Major Immediate Early Promoter that drives IE1 transcription contribute to this repression. We conclude that the HCMV Pentamer represses viral IE transcription.
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Affiliation(s)
- Michael S Ohman
- Institute for Molecular Virology and McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, WI 53706
| | - Emily R Albright
- Institute for Molecular Virology and McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, WI 53706
| | - Christopher B Gelbmann
- Institute for Molecular Virology and McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, WI 53706
| | - Robert F Kalejta
- Institute for Molecular Virology and McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, WI 53706
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3
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Golconda P, Andrade-Medina M, Oberstein A. Subconfluent ARPE-19 Cells Display Mesenchymal Cell-State Characteristics and Behave like Fibroblasts, Rather Than Epithelial Cells, in Experimental HCMV Infection Studies. Viruses 2023; 16:49. [PMID: 38257749 PMCID: PMC10821009 DOI: 10.3390/v16010049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 12/20/2023] [Accepted: 12/25/2023] [Indexed: 01/24/2024] Open
Abstract
Human cytomegalovirus (HCMV) has a broad cellular tropism and epithelial cells are important physiological targets during infection. The retinal pigment epithelial cell line ARPE-19 has been used to model HCMV infection in epithelial cells for decades and remains a commonly used cell type for studying viral entry, replication, and the cellular response to infection. We previously found that ARPE-19 cells, despite being derived from an epithelial cell explant, express extremely low levels of canonical epithelial proteins, such as E-cadherin and EpCAM. Here, we perform comparative studies of ARPE-19 and additional epithelial cell lines with strong epithelial characteristics. We find that ARPE-19 cells cultured under subconfluent conditions resemble mesenchymal fibroblasts, rather than epithelial cells; this is consistent with previous studies showing that ARPE-19 cultures require extended periods of high confluency culture to maintain epithelial characteristics. By reanalyzing public gene expression data and using machine learning, we find evidence that ARPE-19 cultures maintained across many labs exhibit mesenchymal characteristics and that the majority of studies employing ARPE-19 use them in a mesenchymal state. Lastly, by performing experimental HCMV infections across mesenchymal and epithelial cell lines, we find that ARPE-19 cells behave like mesenchymal fibroblasts, producing logarithmic yields of cell-free infectious progeny, while cell lines with strong epithelial character exhibit an atypical infectious cycle and naturally restrict the production of cell-free progeny. Our work highlights important characteristics of the ARPE-19 cell line and suggests that subconfluent ARPE-19 cells may not be optimal for modeling epithelial infection with HCMV or other human viruses. It also suggests that HCMV biosynthesis and/or spread may occur quite differently in epithelial cells compared to mesenchymal cells. These differences could contribute to viral persistence or pathogenesis in epithelial tissues.
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Affiliation(s)
| | | | - Adam Oberstein
- Department of Microbiology and Immunology, College of Medicine, University of Illinois at Chicago, 835 South Wolcott Ave., Chicago, IL 60612, USA; (P.G.); (M.A.-M.)
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4
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O'Brien BS, Mokry RL, Schumacher ML, Rosas-Rogers S, Terhune SS, Ebert AD. Neutralizing antibodies with neurotropic factor treatment maintain neurodevelopmental gene expression upon exposure to human cytomegalovirus. J Virol 2023; 97:e0069623. [PMID: 37796129 PMCID: PMC10653813 DOI: 10.1128/jvi.00696-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 08/23/2023] [Indexed: 10/06/2023] Open
Abstract
IMPORTANCE Human cytomegalovirus (HCMV) infection is the leading cause of non-heritable birth defects worldwide. HCMV readily infects the early progenitor cell population of the developing brain, and we have found that infection leads to significantly downregulated expression of key neurodevelopmental transcripts. Currently, there are no approved therapies to prevent or mitigate the effects of congenital HCMV infection. Therefore, we used human-induced pluripotent stem cell-derived organoids and neural progenitor cells to elucidate the glycoproteins and receptors used in the viral entry process and whether antibody neutralization was sufficient to block viral entry and prevent disruption of neurodevelopmental gene expression. We found that blocking viral entry alone was insufficient to maintain the expression of key neurodevelopmental genes, but neutralization combined with neurotrophic factor treatment provided robust protection. Together, these studies offer novel insight into mechanisms of HCMV infection in neural tissues, which may aid future therapeutic development.
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Affiliation(s)
- Benjamin S. O'Brien
- Department of Cell Biology, Neurobiology, and Anatomy, The Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Rebekah L. Mokry
- Department of Microbiology and Immunology, The Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Megan L. Schumacher
- Department of Microbiology and Immunology, The Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Suzette Rosas-Rogers
- Department of Microbiology and Immunology, The Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Scott S. Terhune
- Department of Microbiology and Immunology, The Medical College of Wisconsin, Milwaukee, Wisconsin, USA
- Marquette University and Medical College of Wisconsin Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Allison D. Ebert
- Department of Cell Biology, Neurobiology, and Anatomy, The Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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5
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Fornara C, Schultz E, Lilleri D, Baldanti F, Ryckman B, Gerna G. Fibroblast, Epithelial and Endothelial Cell-Derived Human Cytomegalovirus Strains Display Distinct Neutralizing Antibody Responses and Varying Levels of gH/gL Complexes. Int J Mol Sci 2023; 24:4417. [PMID: 36901847 PMCID: PMC10003051 DOI: 10.3390/ijms24054417] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/03/2023] [Accepted: 02/16/2023] [Indexed: 02/25/2023] Open
Abstract
In sequential sera from pregnant women with HCMV primary infection (PI), the serum neutralizing activity is higher against virions produced in epithelial and endothelial cells than in fibroblasts. Immunoblotting shows that the pentamer complex/trimer complex (PC/TC) ratio varies according to the producer cell culture type used for the virus preparation to be employed in the neutralizing antibody (NAb) assay, and is lower in fibroblasts and higher in epithelial, and especially endothelial cells. The blocking activity of TC- and PC-specific inhibitors varies according to the PC/TC ratio of virus preparations. The rapid reversion of the virus phenotype following its back passage to the original cell culture (fibroblasts) potentially argues in favor of a producer cell effect on virus phenotype. However, the role of genetic factors cannot be overlooked. In addition to the producer cell type, the PC/TC ratio may differ in single HCMV strains. In conclusion, the NAb activity not only varies with different HCMV strains, but is a dynamic parameter changing according to virus strain, type of target and producer cells, and number of cell culture passages. These findings may have some important implications for the development of both therapeutic antibodies and subunit vaccines.
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Affiliation(s)
- Chiara Fornara
- Microbiology and Virology Unit, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy
| | - Eric Schultz
- Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, MT 59812, USA
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Daniele Lilleri
- Microbiology and Virology Unit, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy
| | - Fausto Baldanti
- Microbiology and Virology Unit, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy
- Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy
| | - Brent Ryckman
- Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, MT 59812, USA
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Giuseppe Gerna
- Laboratories of Genetics, Transplantology and Cardiovascular Diseases, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy
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6
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Neutralization Epitopes in Trimer and Pentamer Complexes Recognized by Potent Cytomegalovirus-Neutralizing Human Monoclonal Antibodies. Microbiol Spectr 2022; 10:e0139322. [PMID: 36342276 PMCID: PMC9784774 DOI: 10.1128/spectrum.01393-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Human cytomegalovirus (HCMV) infects 36% to almost 100% of adults and causes severe complications only in immunocompromised individuals. HCMV viral surface trimeric (gH/gL/gO) and pentameric (gH/gL/UL128/UL130/UL131A) complexes play important roles in HCMV infection and tropism. Here, we isolated and identified a total of four neutralizing monoclonal antibodies (MAbs) derived from HCMV-seropositive blood donors. Based on their reactivity to HCMV trimer and pentamer, these MAbs can be divided into two groups. MAbs PC0012, PC0014, and PC0035 in group 1 bind both trimer and pentamer and neutralize CMV by interfering with the postattachment steps of CMV entering into cells. These three antibodies recognize antigenic epitopes clustered in a similar area, which are overlapped by the epitope recognized by the known neutralizing antibody MSL-109. MAb PC0034 in group 2 binds only to pentamer and neutralizes CMV by blocking the binding of pentamer to cells. Epitope mapping using pentamer mutants showed that amino acid T94 of the subunit UL128 and K27 of UL131A on the pentamer are key epitope-associated residues recognized by PC0034. This study provides new evidence and insight information on the importance of the development of the CMV pentamer as a CMV vaccine. In addition, these newly identified potent CMV MAbs can be attractive candidates for development as antibody therapeutics for the prevention and treatment of HCMV infection. IMPORTANCE The majority of the global population is infected with HCMV, but severe complications occur only in immunocompromised individuals. In addition, CMV infection is a major cause of birth defects in newborns. Currently, there are still no approved prophylactic vaccines or therapeutic monoclonal antibodies (MAbs) for clinical use against HCMV infection. This study identified and characterized a panel of four neutralizing MAbs targeting the HCMV pentamer complex with specific aims to identify a key protein(s) and antigenic epitopes in the HCMV pentamer complex. The study also explored the mechanism by which these newly identified antibodies neutralize HCMV in order to design better HCMV vaccines focusing on the pentamer and to provide attractive candidates for the development of effective cocktail therapeutics for the prevention and treatment of HCMV infection.
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7
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Flomm FJ, Soh TK, Schneider C, Wedemann L, Britt HM, Thalassinos K, Pfitzner S, Reimer R, Grünewald K, Bosse JB. Intermittent bulk release of human cytomegalovirus. PLoS Pathog 2022; 18:e1010575. [PMID: 35925870 PMCID: PMC9352052 DOI: 10.1371/journal.ppat.1010575] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 05/06/2022] [Indexed: 01/24/2023] Open
Abstract
Human Cytomegalovirus (HCMV) can infect a variety of cell types by using virions of varying glycoprotein compositions. It is still unclear how this diversity is generated, but spatio-temporally separated envelopment and egress pathways might play a role. So far, one egress pathway has been described in which HCMV particles are individually enveloped into small vesicles and are subsequently exocytosed continuously. However, some studies have also found enveloped virus particles inside multivesicular structures but could not link them to productive egress or degradation pathways. We used a novel 3D-CLEM workflow allowing us to investigate these structures in HCMV morphogenesis and egress at high spatio-temporal resolution. We found that multiple envelopment events occurred at individual vesicles leading to multiviral bodies (MViBs), which subsequently traversed the cytoplasm to release virions as intermittent bulk pulses at the plasma membrane to form extracellular virus accumulations (EVAs). Our data support the existence of a novel bona fide HCMV egress pathway, which opens the gate to evaluate divergent egress pathways in generating virion diversity.
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Affiliation(s)
- Felix J. Flomm
- Centre for Structural Systems Biology, Hamburg, Germany
- Hannover Medical School, Institute of Virology, Hannover, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
- Leibniz-Institute of Virology (LIV), Hamburg, Germany
| | - Timothy K. Soh
- Centre for Structural Systems Biology, Hamburg, Germany
- Hannover Medical School, Institute of Virology, Hannover, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
- Leibniz-Institute of Virology (LIV), Hamburg, Germany
| | | | - Linda Wedemann
- Centre for Structural Systems Biology, Hamburg, Germany
- Hannover Medical School, Institute of Virology, Hannover, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
- Leibniz-Institute of Virology (LIV), Hamburg, Germany
| | - Hannah M. Britt
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Konstantinos Thalassinos
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
- Institute of Structural and Molecular Biology, Birkbeck College, University of London, London, United Kingdom
| | | | | | - Kay Grünewald
- Centre for Structural Systems Biology, Hamburg, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
- Leibniz-Institute of Virology (LIV), Hamburg, Germany
- University of Hamburg, Department of Chemistry, Hamburg, Germany
| | - Jens B. Bosse
- Centre for Structural Systems Biology, Hamburg, Germany
- Hannover Medical School, Institute of Virology, Hannover, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
- Leibniz-Institute of Virology (LIV), Hamburg, Germany
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8
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A comparative analysis depicting the disease characteristics and phylogenetic signature of human cytomegalovirus infection in Human Immunodeficiency Virus 1 seropositive patients with end-organ retinitis and gastro-enteric diseases. Sci Rep 2022; 12:7617. [PMID: 35538132 PMCID: PMC9091246 DOI: 10.1038/s41598-022-11727-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 04/11/2022] [Indexed: 11/08/2022] Open
Abstract
During advanced HIV infection, Human Cytomegalovirus (HCMV) has been proven to produce devitalizing end-organ diseases (EOD). The interactive co-existence of HIV and HCMV has been reported by many researchers and has been suggested to be linked with a more aggressive disease state. This study has been designed to bring forward an assessment of the clinical risk factors capable of defining the conditions of HCMV induced retinitis and gastro-enteric diseases among HIV1 seropositive patients. We also intended to analyse the phylogenetic variation if any, among the infecting virus types inducing the two separate clinical conditions. The patients were arranged in three different groups; (Group 1 with 26 individuals and group 2 and group 3 with 25 individuals each) based on their current status of HIV and HCMV infections. Serum ELISA, qualitative and quantitative detection of HCMV DNA, Real time mRNA expression study, sequencing, and phylogenetic analysis were performed. All statistical analyses and graphs were exercised using relevant software. We found that in HIV patients with HCMV induced end-organ diseases the components of the CXCL9, 10, 11-CXCR3 chemokine pathway is highly expressed with significant differences existing among patients with retinitis and gastrointestinal disease. We found that the gL gene sequences from the retinitis (HR) group clustered almost separately from that of the gastroenteritis (HG) group in the phylogenetic tree. It may be suggested that a form of natural selection pressure is working on the clinical HCMV strains creating a slight divergence in their phylogenetic lineage thereby helping them adapt to the particular tissue microenvironment they are colonizing.
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9
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Choi KY, El-Hamdi NS, McGregor A. Cross Strain Protection against Cytomegalovirus Reduces DISC Vaccine Efficacy against CMV in the Guinea Pig Model. Viruses 2022; 14:760. [PMID: 35458490 PMCID: PMC9031936 DOI: 10.3390/v14040760] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/24/2022] [Accepted: 03/30/2022] [Indexed: 01/27/2023] Open
Abstract
Congenital cytomegalovirus (CMV) is a leading cause of disease in newborns and a vaccine is a high priority. The guinea pig is the only small animal model for congenital CMV but requires guinea pig cytomegalovirus (GPCMV). Previously, a disabled infectious single cycle (DISC) vaccine strategy demonstrated complete protection against congenital GPCMV (22122 strain) and required neutralizing antibodies to various viral glycoprotein complexes. This included gB, essential for all cell types, and the pentamer complex (PC) for infection of non-fibroblast cells. All GPCMV research has utilized prototype strain 22122 limiting the translational impact, as numerous human CMV strains exist allowing re-infection and congenital CMV despite convalescent immunity. A novel GPCMV strain isolate (designated TAMYC) enabled vaccine cross strain protection studies. A GPCMV DISC (PC+) vaccine (22122 strain) induced a comprehensive immune response in animals, but vaccinated animals challenged with the TAMYC strain virus resulted in sustained viremia and the virus spread to target organs (liver, lung and spleen) with a significant viral load in the salivary glands. Protection was better than natural convalescent immunity, but the results fell short of previous DISC vaccine sterilizing immunity against the homologous 22122 virus challenge, despite a similarity in viral glycoprotein sequences between strains. The outcome suggests a limitation of the current DISC vaccine design against heterologous infection.
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Affiliation(s)
| | | | - Alistair McGregor
- Department Microbial Pathogenesis & Immunology, College of Medicine, Texas A&M University, Bryan, TX 77807, USA; (K.Y.C.); (N.S.E.-H.)
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10
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Tyl MD, Betsinger CN, Cristea IM. Virus-host protein interactions as footprints of human cytomegalovirus replication. Curr Opin Virol 2022; 52:135-147. [PMID: 34923282 PMCID: PMC8844139 DOI: 10.1016/j.coviro.2021.11.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 11/24/2021] [Indexed: 02/03/2023]
Abstract
Human cytomegalovirus (HCMV) is a pervasive β-herpesvirus that causes lifelong infection. The lytic replication cycle of HCMV is characterized by global organelle remodeling and dynamic virus-host interactions, both of which are necessary for productive HCMV replication. With the advent of new technologies for investigating protein-protein and protein-nucleic acid interactions, numerous critical interfaces between HCMV and host cells have been identified. Here, we review temporal and spatial virus-host interactions that support different stages of the HCMV replication cycle. Understanding how HCMV interacts with host cells during entry, replication, and assembly, as well as how it interfaces with host cell metabolism and immune responses promises to illuminate processes that underlie the biology of infection and the resulting pathologies.
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Affiliation(s)
- Matthew D. Tyl
- Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Washington Road, Princeton, NJ 08544, USA
| | - Cora N. Betsinger
- Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Washington Road, Princeton, NJ 08544, USA
| | - Ileana M. Cristea
- Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Washington Road, Princeton, NJ 08544, USA,Corresponding author and lead contact: Ileana M. Cristea, 210 Lewis Thomas Laboratory, Department of Molecular Biology, Princeton University, Princeton, NJ 08544, Tel: 6092589417, Fax: 6092584575,
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11
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Varicella-zoster virus: molecular controls of cell fusion-dependent pathogenesis. Biochem Soc Trans 2021; 48:2415-2435. [PMID: 33259590 DOI: 10.1042/bst20190511] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 10/30/2020] [Accepted: 11/03/2020] [Indexed: 12/30/2022]
Abstract
Varicella-zoster virus (VZV) is the causative agent of chicken pox (varicella) and shingles (zoster). Although considered benign diseases, both varicella and zoster can cause complications. Zoster is painful and can lead to post herpetic neuralgia. VZV has also been linked to stroke, related to giant cell arteritis in some cases. Vaccines are available but the attenuated vaccine is not recommended in immunocompromised individuals and the efficacy of the glycoprotein E (gE) based subunit vaccine has not been evaluated for the prevention of varicella. A hallmark of VZV pathology is the formation of multinucleated cells termed polykaryocytes in skin lesions. This cell-cell fusion (abbreviated as cell fusion) is mediated by the VZV glycoproteins gB, gH and gL, which constitute the fusion complex of VZV, also needed for virion entry. Expression of gB, gH and gL during VZV infection and trafficking to the cell surface enables cell fusion. Recent evidence supports the concept that cellular processes are required for regulating cell fusion induced by gB/gH-gL. Mutations within the carboxyl domains of either gB or gH have profound effects on fusion regulation and dramatically restrict the ability of VZV to replicate in human skin. This loss of regulation modifies the transcriptome of VZV infected cells. Furthermore, cellular proteins have significant effects on the regulation of gB/gH-gL-mediated cell fusion and the replication of VZV, exemplified by the cellular phosphatase, calcineurin. This review provides the current state-of-the-art knowledge about the molecular controls of cell fusion-dependent pathogenesis caused by VZV.
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12
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Cell type-specific biogenesis of novel vesicles containing viral products in human cytomegalovirus infection. J Virol 2021; 95:JVI.02358-20. [PMID: 33762413 PMCID: PMC8139684 DOI: 10.1128/jvi.02358-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Human cytomegalovirus (HCMV), while highly restricted for the human species, infects an diverse array of cell types in the host. Patterns of infection are dictated by the cell type infected, but cell type-specific factors and how they impact tropism for specific cell types is poorly understood. Previous studies in primary endothelial cells showed that HCMV infection induces large multivesicular-like bodies (MVBs) that incorporate viral products, including dense bodies (DBs) and virions. Here we define the nature of these large vesicles using a recombinant virus where UL32, encoding the pp150 tegument protein, is fused in frame with green fluorescent protein (GFP, TB40/E-UL32-GFP). In fibroblasts, UL32-GFP-positive vesicles were marked with classical markers of MVBs, including CD63 and lysobisphosphatidic acid (LBPA), both classical MVB markers, as well as the clathrin and LAMP1. Unexpectedly, UL32-GFP-positive vesicles in primary human microvascular endothelial cells (HMVECs) were not labeled by CD63, and LBPA was completely lost from infected cells. We defined these UL32-positive vesicles in endothelial cells using markers for the cis-Golgi (GM130), lysosome (LAMP1), and autophagy (LC3B). These findings suggest that UL32-GFP containing MVBs in fibroblasts are derived from the canonical endocytic pathway and takeover classical exosomal release pathway. However, UL32-GFP containing MVBs in HMVECs are derived from the early biosynthetic pathway and exploit a less characterized early Golgi-LAMP1-associated non- canonical secretory autophagy pathway. These results reveal striking cell-type specific membrane trafficking differences in host pathways that are exploited by HCMV, which may reflect distinct pathways for virus egress.ImportanceHuman cytomegalovirus (HCMV) is a herpesvirus that, like all herpesvirus, that establishes a life-long infection. HCMV remains a significant cause of morbidity and mortality in the immunocompromised and HCMV seropositivity is associated with age-related pathology. HCMV infects many cells in the human host and the biology underlying the different patterns of infection in different cell types is poorly understood. Endothelial cells are important target of infection that contribute to hematogenous spread of the virus to tissues. Here we define striking differences in the biogenesis of large vesicles that incorporate virions in fibroblasts and endothelial cells. In fibroblasts, HCMV is incorporated into canonical MVBs derived from an endocytic pathway, whereas HCMV matures through vesicles derived from the biosynthetic pathway in endothelial cells. This work defines basic biological differences between these cell types that may impact how progeny virus is trafficked out of infected cells.
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13
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Gatault P, Jones IKA, Meyer C, Kreklywich C, Alexander T, Smith PP, Denton M, Powell J, Orloff SL, Streblow DN. Rat and human cytomegalovirus ORF116 encodes a virion envelope glycoprotein required for infectivity. Virology 2021; 557:23-33. [PMID: 33601113 PMCID: PMC8019331 DOI: 10.1016/j.virol.2020.12.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 12/22/2020] [Accepted: 12/23/2020] [Indexed: 11/17/2022]
Abstract
Herpesviruses encode multiple glycoproteins required for different stages of viral attachment, fusion, and envelopment. The protein encoded by the human cytomegalovirus (HCMV) open reading frame UL116 forms a stable complex with glycoprotein H that is incorporated into virions. However, the function of this complex remains unknown. Herein, we characterize R116, the rat CMV (RCMV) putative homolog of UL116. Two R116 transcripts were identified in fibroblasts with three proteins expressed with molecular weights of 42, 58, and 82 kDa. R116 is N-glycosylated, expressed with late viral gene kinetics, and is incorporated into the virion envelope. RCMV lacking R116 failed to result in productive infection of fibroblasts and siRNA knockdown of R116 substantially reduced RCMV infectivity. Complementation in trans of an R116-deficient virus restored ability of the virus to infect fibroblasts. Finally, UL116 knockdown also decreased HCMV infectivity indicating that R116 and UL116 both contribute to viral infectivity.
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Affiliation(s)
- Philippe Gatault
- Renal Transplant Unit, 10 Boulevard Tonnellé, University Hospital of Tours, France
| | - Iris K A Jones
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Christine Meyer
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Craig Kreklywich
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Timothy Alexander
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Patricia P Smith
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Michael Denton
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Josh Powell
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Susan L Orloff
- Department of Surgery, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Daniel N Streblow
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR, 97239, USA.
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14
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Choi KY, El-Hamdi NS, McGregor A. A trimeric capable gB CMV vaccine provides limited protection against a highly cell associated and epithelial tropic strain of cytomegalovirus in guinea pigs. J Gen Virol 2021; 102. [PMID: 33729125 DOI: 10.1099/jgv.0.001579] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Multiple strains of human cytomegalovirus (HCMV) can cause congenital cytomegalovirus (cCMV) by primary or secondary infection. The viral gB glycoprotein is a leading vaccine candidate, essential for infection of all cell-types, and immunodominant antibody target. Guinea pig cytomegalovirus (GPCMV) is the only small animal model for cCMV. Various gB vaccines have shown efficacy but studies have utilized truncated gB and protection against prototype strain 22122 with preferential tropism to fibroblasts despite encoding a gH-based pentamer complex for non-fibroblast infection. A highly cell-associated novel strain of GPCMV (TAMYC) with 99 % identity in gB sequence to 22122 exhibited preferred tropism to epithelial cells. An adenovirus vaccine encoding full-length gB (AdgB) was highly immunogenic and partially protected against 22122 strain challenge in vaccinated animals but not when challenged with TAMYC strain. GPCMV studies with AdgB vaccine sera on numerous cell-types demonstrated impaired neutralization (NA50) compared to fibroblasts. GPCMV-convalescent sera including pentamer complex antibodies increased virus neutralization on non-fibroblasts and anti-gB depletion from GPCMV-convalescent sera had minimal impact on epithelial cell neutralization. GPCMV(PC+) 22122-convalescent animals challenged with TAMYC exhibited higher protection compared to AdgB vaccine. Overall, results suggest that antibody response to both gB and PC are important components of a GPCMV vaccine.
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Affiliation(s)
- K Yeon Choi
- Dept. Microbial Pathogenesis & Immunology, College of Medicine, Texas A&M University, Bryan, TX, USA
| | - Nadia S El-Hamdi
- Dept. Microbial Pathogenesis & Immunology, College of Medicine, Texas A&M University, Bryan, TX, USA
| | - Alistair McGregor
- Dept. Microbial Pathogenesis & Immunology, College of Medicine, Texas A&M University, Bryan, TX, USA
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15
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Jones IKA, Haese NN, Gatault P, Streblow ZJ, Andoh TF, Denton M, Streblow CE, Bonin K, Kreklywich CN, Burg JM, Orloff SL, Streblow DN. Rat Cytomegalovirus Virion-Associated Proteins R131 and R129 Are Necessary for Infection of Macrophages and Dendritic Cells. Pathogens 2020; 9:E963. [PMID: 33228102 PMCID: PMC7699341 DOI: 10.3390/pathogens9110963] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 11/05/2020] [Accepted: 11/17/2020] [Indexed: 12/15/2022] Open
Abstract
Cytomegalovirus (CMV) establishes persistent, latent infection in hosts, causing diseases in immunocompromised patients, transplant recipients, and neonates. CMV infection modifies the host chemokine axis by modulating chemokine and chemokine receptor expression and by encoding putative chemokine and chemokine receptor homologues. The viral proteins have roles in cellular signaling, migration, and transformation, as well as viral dissemination, tropism, latency and reactivation. Herein, we review the contribution of CMV-encoded chemokines and chemokine receptors to these processes, and further elucidate the viral tropism role of rat CMV (RCMV) R129 and R131. These homologues of the human CMV (HCMV)-encoded chemokines UL128 and UL130 are of particular interest because of their dual role as chemokines and members of the pentameric entry complex, which is required for entry into cell types that are essential for viral transmission and dissemination. The contributions of UL128 and UL130 to acceleration of solid organ transplant chronic rejection are poorly understood, and are in need of an effective in vivo model system to elucidate the phenomenon. We demonstrated similar molecular entry requirements for R129 and R131 in the rat cells, as observed for HCMV, and provided evidence that R129 and R131 are part of the viral entry complex required for entry into macrophages, dendritic cells, and bone marrow cells.
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Affiliation(s)
- Iris K. A. Jones
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR 97239, USA; (I.K.A.J.); (N.N.H.); (Z.J.S.); (T.F.A.); (M.D.); (C.E.S.); (K.B.); (C.N.K.)
| | - Nicole N. Haese
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR 97239, USA; (I.K.A.J.); (N.N.H.); (Z.J.S.); (T.F.A.); (M.D.); (C.E.S.); (K.B.); (C.N.K.)
| | - Philippe Gatault
- Renal Transplant Unit, 10 Boulevard Tonnellé, University Hospital of Tours, 37032 Tours, France;
| | - Zachary J. Streblow
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR 97239, USA; (I.K.A.J.); (N.N.H.); (Z.J.S.); (T.F.A.); (M.D.); (C.E.S.); (K.B.); (C.N.K.)
| | - Takeshi F. Andoh
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR 97239, USA; (I.K.A.J.); (N.N.H.); (Z.J.S.); (T.F.A.); (M.D.); (C.E.S.); (K.B.); (C.N.K.)
- Department of Surgery, Oregon Health & Science University, Portland, OR 97239, USA; (J.M.B.); (S.L.O.)
| | - Michael Denton
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR 97239, USA; (I.K.A.J.); (N.N.H.); (Z.J.S.); (T.F.A.); (M.D.); (C.E.S.); (K.B.); (C.N.K.)
| | - Cassilyn E. Streblow
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR 97239, USA; (I.K.A.J.); (N.N.H.); (Z.J.S.); (T.F.A.); (M.D.); (C.E.S.); (K.B.); (C.N.K.)
| | - Kiley Bonin
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR 97239, USA; (I.K.A.J.); (N.N.H.); (Z.J.S.); (T.F.A.); (M.D.); (C.E.S.); (K.B.); (C.N.K.)
| | - Craig N. Kreklywich
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR 97239, USA; (I.K.A.J.); (N.N.H.); (Z.J.S.); (T.F.A.); (M.D.); (C.E.S.); (K.B.); (C.N.K.)
| | - Jennifer M. Burg
- Department of Surgery, Oregon Health & Science University, Portland, OR 97239, USA; (J.M.B.); (S.L.O.)
| | - Susan L. Orloff
- Department of Surgery, Oregon Health & Science University, Portland, OR 97239, USA; (J.M.B.); (S.L.O.)
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR 97239, USA
| | - Daniel N. Streblow
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR 97239, USA; (I.K.A.J.); (N.N.H.); (Z.J.S.); (T.F.A.); (M.D.); (C.E.S.); (K.B.); (C.N.K.)
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16
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Chinta P, Garcia EC, Tajuddin KH, Akhidenor N, Davis A, Faure L, Spencer JV. Control of Cytokines in Latent Cytomegalovirus Infection. Pathogens 2020; 9:pathogens9100858. [PMID: 33096622 PMCID: PMC7589642 DOI: 10.3390/pathogens9100858] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/17/2020] [Accepted: 10/19/2020] [Indexed: 12/12/2022] Open
Abstract
Human cytomegalovirus (HCMV) has evolved a number of mechanisms for long-term co-existence within its host. HCMV infects a wide range of cell types, including fibroblasts, epithelial cells, monocytes, macrophages, dendritic cells, and myeloid progenitor cells. Lytic infection, with the production of infectious progeny virions, occurs in differentiated cell types, while undifferentiated myeloid precursor cells are the primary site of latent infection. The outcome of HCMV infection depends partly on the cell type and differentiation state but is also influenced by the composition of the immune environment. In this review, we discuss the role of early interactions between HCMV and the host immune system, particularly cytokine and chemokine networks, that facilitate the establishment of lifelong latent infection. A better understanding of these cytokine signaling pathways could lead to novel therapeutic targets that might prevent latency or eradicate latently infected cells.
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17
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Human Cytomegalovirus Envelope Protein gpUL132 Regulates Infectious Virus Production through Formation of the Viral Assembly Compartment. mBio 2020; 11:mBio.02044-20. [PMID: 32994323 PMCID: PMC7527726 DOI: 10.1128/mbio.02044-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Following infection of permissive cells, human cytomegalovirus (HCMV) induces the reorganization of intracellular membranes resulting in the formation of a distinctive membranous compartment in the cytoplasm of infected cells. This compartment has been designated the viral assembly compartment (AC) and is thought to be a site for cytoplasmic virion assembly and envelopment. In this study, we have demonstrated that a single virion envelope glycoprotein is essential for AC formation in infected cells, and in its absence, there is a significant decrease in the production of infectious virions. These findings are consistent with those from other studies that have demonstrated the importance of host cell proteins in the formation of the AC and demonstrate a critical role of a single virion protein in AC formation and the efficient assembly of infectious virus. The human cytomegalovirus (HCMV) UL132 open reading frame encodes a 270-amino-acid type I envelope glycoprotein, gpUL132. The deletion of UL132 (ΔUL132) from the HCMV genome results in a pronounced deficit in virus yield, with an approximately 2-log decrease in the production of infectious virus compared to the wild-type (WT) virus. Characterization of the ΔUL132 mutant virus indicated that it was less infectious with a high particle-to-infectious unit ratio and an altered composition of virion proteins compared to the WT virus. In addition, the viral assembly compartment (AC) failed to form in cells infected with the ΔUL132 mutant virus. The expression of gpUL132 in trans rescued the defects in the morphogenesis of the AC in cells infected with the ΔUL132 mutant virus and in infectious virus production. Furthermore, using cell lines expressing chimeric proteins, we demonstrated that the cytosolic domain of gpUL132 was sufficient to rescue AC formation and WT levels of virus production. Progeny virions from ΔUL132-infected cells expressing the cytosolic domain of gpUL132 exhibited particle-to-infectious unit ratios similar to those of the WT virus. Together, our findings argue that gpUL132 is essential for HCMV AC formation and the efficient production of infectious particles, thus highlighting the importance of this envelope protein for the virus-induced reorganization of intracellular membranes and AC formation in the assembly of infectious virus.
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18
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Choi KY, El-Hamdi NS, McGregor A. Convalescent Immunity to Guinea Pig Cytomegalovirus Induces Limited Cross Strain Protection against Re-Infection but High-Level Protection against Congenital Disease. Int J Mol Sci 2020; 21:ijms21175997. [PMID: 32825429 PMCID: PMC7504201 DOI: 10.3390/ijms21175997] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/12/2020] [Accepted: 08/19/2020] [Indexed: 12/24/2022] Open
Abstract
The guinea pig is the only small animal model for congenital cytomegalovirus (cCMV) but requires guinea pig cytomegalovirus (GPCMV). Current GPCMV research utilizes prototype strain 22122, which limits the translational impact of GPCMV as numerous human CMV strains exist and cCMV is possible in the setting of re-infection. A novel strain of GPCMV (TAMYC) exhibited differences to 22122 in various glycoproteins with GP74 (gO homolog) the most variable (25% difference). Antibody ELISAs for TAMYC-convalescent animals evoked similar immune response to viral glycoprotein complexes (gB, gH/gL, gM/gN, pentamer) and cell-mediated response to pp65 homolog (GP83). Convalescent sera from TAMYC-infected animals neutralized GPCMV infection on fibroblasts but was less effective on epithelial cells. TAMYC-convalescent animals were not protected from dissemination of heterogenous virus challenge (22122). However, in a cCMV protection study, TAMYC-convalescent animals challenged mid-pregnancy (22122) exhibited high-level protection against cCMV compared to seronegative animals with pup transmission reduced from 80% (control) to 12%. Overall, pre-existing immunity in guinea pigs provides limited ability to prevent GPCMV re-infection by a different viral strain but provides a high level of protection against cCMV in heterogenous strain challenge. This level of cross protection against cCMV should be a prerequisite of any CMV vaccine.
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19
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A glycoprotein B-neutralizing antibody structure at 2.8 Å uncovers a critical domain for herpesvirus fusion initiation. Nat Commun 2020; 11:4141. [PMID: 32811830 PMCID: PMC7435202 DOI: 10.1038/s41467-020-17911-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 07/21/2020] [Indexed: 11/24/2022] Open
Abstract
Members of the Herpesviridae, including the medically important alphaherpesvirus varicella-zoster virus (VZV), induce fusion of the virion envelope with cell membranes during entry, and between cells to form polykaryocytes in infected tissues. The conserved glycoproteins, gB, gH and gL, are the core functional proteins of the herpesvirus fusion complex. gB serves as the primary fusogen via its fusion loops, but functions for the remaining gB domains remain unexplained. As a pathway for biological discovery of domain function, our approach used structure-based analysis of the viral fusogen together with a neutralizing antibody. We report here a 2.8 Å cryogenic-electron microscopy structure of native gB recovered from VZV-infected cells, in complex with a human monoclonal antibody, 93k. This high-resolution structure guided targeted mutagenesis at the gB-93k interface, providing compelling evidence that a domain spatially distant from the gB fusion loops is critical for herpesvirus fusion, revealing a potential new target for antiviral therapies. Herpesvirus virions have an outer lipid membrane dotted with glycoproteins that enable fusion with cell membranes to initiate entry and establish infection. Here the authors elucidate the structural mechanism of a neutralizing antibody derived from a patient infected by the herpesvirus varicella-zoster virus and targeted to its fusogen, glycoprotein-B.
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20
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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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21
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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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22
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Okumura M, Matsuura-Miura M, Makino R, Miura T, Noguchi K, Majima R, Koshizuka T, Inoue N. Enhancement of guinea pig cytomegalovirus infection by two endogenously expressed components of the pentameric glycoprotein complex in epithelial cells. Sci Rep 2020; 10:8530. [PMID: 32444790 PMCID: PMC7244513 DOI: 10.1038/s41598-020-65545-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 05/06/2020] [Indexed: 11/09/2022] Open
Abstract
A better understanding of the mechanisms underlying cell tropisms and the efficiency of viral infection is critical for the development of vaccines and antiviral drugs for viral diseases. In this study, we worked on the entry mechanisms of guinea pig cytomegalovirus and found that endogenous expression of a combination of two components (GP131 and GP133) of the pentameric glycoprotein complex, which is required for non-fibroblast cell tropisms, enhanced viral infection more than 10-fold. In addition, D138A alteration in GP131 increased this enhancement by an additional 10-fold. Although differences in the efficiency of viral infection among various cell types are usually explained by differences in viral entry or traffic processes, our experimental evidences dismissed such possibilities. Instead, our findings that i) endogenous expression of GP131 and GP133 after nuclear delivery of viral DNA still enhanced infection and ii) an HDAC inhibitor overcame the need of the endogenous expression led us to hypothesize a novel mechanism that controls the efficiency of viral infection through the activation of gene expression from viral DNA delivered to the nuclei. Further studies of this unexpected phenomena warrant to understand novel but also general mechanisms for cell tropisms of viral infection and determinants that control infection efficiency.
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Affiliation(s)
- Misaki Okumura
- Microbiology and Immunology, Gifu Pharmaceutical University, Gifu, Japan
| | - Miku Matsuura-Miura
- Microbiology and Immunology, Gifu Pharmaceutical University, Gifu, Japan.,Akashi City Hall, Hyogo, Japan
| | - Reina Makino
- Microbiology and Immunology, Gifu Pharmaceutical University, Gifu, Japan
| | - Takuya Miura
- Microbiology and Immunology, Gifu Pharmaceutical University, Gifu, Japan.,JCR Pharmaceuticals Co., Ltd., Hyogo, Japan
| | - Kazuma Noguchi
- Microbiology and Immunology, Gifu Pharmaceutical University, Gifu, Japan
| | - Ryuichi Majima
- Microbiology and Immunology, Gifu Pharmaceutical University, Gifu, Japan
| | - Tetsuo Koshizuka
- Microbiology and Immunology, Gifu Pharmaceutical University, Gifu, Japan
| | - Naoki Inoue
- Microbiology and Immunology, Gifu Pharmaceutical University, Gifu, Japan.
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23
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Bucher L, Kappler-Gratias S, Desbois N, Bystricky K, Gallardo F, Gros CP. A 3- and A 2B-nitrocorroles: synthesis and antiviral activity evaluation against human cytomegalovirus infection. RSC Med Chem 2020; 11:771-782. [PMID: 33479674 DOI: 10.1039/d0md00034e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 04/16/2020] [Indexed: 12/22/2022] Open
Abstract
Human cytomegalovirus (hCMV) is responsible for several pathologies impacting immunocompromised patients and can trigger life-threatening infection. Several antivirals are available and are used in the clinic, but hCMV resistant strains have appeared and patients have encountered therapeutic failure. Hence, there is a constant need for new best in class or first in class antiviral molecules. We have previously shown that nitrocorroles could be used as a potent anti-hCMV agent without acute toxicity in mice. They therefore represent an excellent platform to perform structure-activity relationship (SAR) studies and to increase efficiency or reduce toxicity. We have generated original A2B- and A3-substituted nitrocorroles and have discovered optimized compounds with selectivity indices above 200. These compounds are easily synthesized in only one to two-step reactions; they are up-scalable and cost efficient. They are therefore excellent candidates for hCMV therapies and they pave the way for a new generation of molecules.
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Affiliation(s)
- Léo Bucher
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB) , UMR CNRS 6302 , Université Bourgogne Franche-Comté , 9 avenue Alain Savary, BP 47870 , 21078 Dijon Cedex , France .
| | | | - Nicolas Desbois
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB) , UMR CNRS 6302 , Université Bourgogne Franche-Comté , 9 avenue Alain Savary, BP 47870 , 21078 Dijon Cedex , France .
| | - Kerstin Bystricky
- Centre de Biologie Intégrative (CBI) , Laboratoire de Biologie Moléculaire Eucaryote (LBME) , University of Toulouse , UPS , CNRS , Route de Narbonne , F-31062 Toulouse , France.,Institut Universitaire de France (IUF) , France
| | - Franck Gallardo
- NeoVirTech , SAS , 1 place Pierre Potier, Oncopole , 31106 Toulouse , France .
| | - Claude P Gros
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB) , UMR CNRS 6302 , Université Bourgogne Franche-Comté , 9 avenue Alain Savary, BP 47870 , 21078 Dijon Cedex , France .
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24
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Baasch S, Ruzsics Z, Henneke P. Cytomegaloviruses and Macrophages-Friends and Foes From Early on? Front Immunol 2020; 11:793. [PMID: 32477336 PMCID: PMC7235172 DOI: 10.3389/fimmu.2020.00793] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 04/07/2020] [Indexed: 01/01/2023] Open
Abstract
Starting at birth, newborn infants are exposed to numerous microorganisms. Adaptation of the innate immune system to them is a delicate process, with potentially advantageous and harmful implications for health development. Cytomegaloviruses (CMVs) are highly adapted to their specific mammalian hosts, with which they share millions of years of co-evolution. Throughout the history of mankind, human CMV has infected most infants in the first months of life without overt implications for health. Thus, CMV infections are intertwined with normal immune development. Nonetheless, CMV has retained substantial pathogenicity following infection in utero or in situations of immunosuppression, leading to pathology in virtually any organ and particularly the central nervous system (CNS). CMVs enter the host through mucosal interfaces of the gastrointestinal and respiratory tract, where macrophages (MACs) are the most abundant immune cell type. Tissue MACs and their potential progenitors, monocytes, are established target cells of CMVs. Recently, several discoveries have revolutionized our understanding on the pre- and postnatal development and site-specific adaptation of tissue MACs. In this review, we explore experimental evidences and concepts on how CMV infections may impact on MAC development and activation as part of host-virus co-adaptation.
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Affiliation(s)
- Sebastian Baasch
- Institute for Immunodeficiency, Center for Chronic Immunodeficiency (CCI), Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center for Pediatrics and Adolescent Medicine, University of Freiburg, Freiburg, Germany
| | - Zsolt Ruzsics
- Institute of Virology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Philipp Henneke
- Institute for Immunodeficiency, Center for Chronic Immunodeficiency (CCI), Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center for Pediatrics and Adolescent Medicine, University of Freiburg, Freiburg, Germany
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Seng C, Sharthiya H, Tiwari V, Fornaro M. Involvement of heparan sulfate during mouse cytomegalovirus infection in murine-derived immortalized neuronal cell line. Future Virol 2020. [DOI: 10.2217/fvl-2019-0161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cytomegalovirus infection cause of severe developmental disorders of the CNS. Aim: In this study, we utilized a differentiated mouse-derived hippocampal cell line (dHT22) to understand mouse CMV (MCMV) infection. Results: The expression of immediate early genes ( IE) 1 and 3 confirmed the time-dependent susceptibility of dHT22 cells to MCMV infection. MCMV infection alters the cellular distribution of heparan sulfate (HS). In addition, pretreatment with heparinase significantly reduces virus infectivity. Conclusion: The compartmentalization of HS in MCMV infected cells suggests multiple roles of HS in virus life cycle ranging from viral entry to viral transport and cellular remodeling. An enzymatic heparinase assay confirmed that HS is critical for viral entry and trafficking.
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Affiliation(s)
- Chanmoly Seng
- Department of Biomedical Sciences, College of Graduate Studies & Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA
| | - Harsh Sharthiya
- Department of Anatomy, College of Graduate Studies & Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA
| | - Vaibhav Tiwari
- Department of Microbiology & Immunology, College of Graduate Studies & Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA
| | - Michele Fornaro
- Department of Anatomy, College of Graduate Studies & Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA
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Vo M, Aguiar A, McVoy MA, Hertel L. Cytomegalovirus Strain TB40/E Restrictions and Adaptations to Growth in ARPE-19 Epithelial Cells. Microorganisms 2020; 8:microorganisms8040615. [PMID: 32344555 PMCID: PMC7232150 DOI: 10.3390/microorganisms8040615] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 04/17/2020] [Accepted: 04/22/2020] [Indexed: 12/02/2022] Open
Abstract
Despite displaying broad tropism in vivo, human cytomegalovirus (CMV) contained in bodily fluids replicates inefficiently in most cultured cell types except fibroblasts. As propagation in fibroblasts leads to the accumulation of genomic changes, a number of strains were generated by serial passaging on endothelial cells. One of these, TB40/E, was shown to contain a mixture of genetically distinct virus variants, and to retain tropism for fibroblasts, endothelial and epithelial cells. Cloning of an endotheliotropic subpopulation produced the TB40-BAC4 variant, extensively used in CMV tropism studies. Because TB40-BAC4 represents only one of the different variants comprising TB40/E, we generated a series of epithelial-cell adapted stocks derived from a TB40/E mixed stock, rather than from TB40-BAC4. Within two passages on ARPE-19 cells, virus populations were produced with the ability to enter and initiate replication with similar efficiencies in both epithelial cells and fibroblasts. Although the ability to release progeny also increased, cell-free virus yields from ARPE-19 cells remained consistently two to three-logs lower than from fibroblasts, hinting at the existence of a post-entry and post-genome synthesis block in epithelial cells. Multinucleated syncytia also rapidly appeared exclusively in ARPE-19 cell cultures, where their numbers and dimensions increased with virus passage. Irrespective of the number of infected nuclei comprising each syncytium, however, only one cytoplasmic virion assembly compartment was consistently observed, leading us to speculate that improvements in entry efficiency associated with ARPE-19 cell adaptation lead to the development of syncytia, which may negatively affect progeny release by limiting the amount of resources available to maturing virions.
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Affiliation(s)
- Mai Vo
- Department of Pediatrics, University of California San Francisco, Oakland, CA 94611, USA; (M.V.); (A.A.)
| | - Alexis Aguiar
- Department of Pediatrics, University of California San Francisco, Oakland, CA 94611, USA; (M.V.); (A.A.)
| | - Michael A. McVoy
- Department of Pediatrics, Virginia Commonwealth University, Richmond, VA 23229, USA;
| | - Laura Hertel
- Department of Pediatrics, University of California San Francisco, Oakland, CA 94611, USA; (M.V.); (A.A.)
- Correspondence:
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Modeling Human Cytomegalovirus-Induced Microcephaly in Human iPSC-Derived Brain Organoids. CELL REPORTS MEDICINE 2020; 1:100002. [PMID: 33205055 PMCID: PMC7659592 DOI: 10.1016/j.xcrm.2020.100002] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 01/16/2020] [Accepted: 02/28/2020] [Indexed: 12/13/2022]
Abstract
Although congenital infection by human cytomegalovirus (HCMV) is well recognized as a leading cause of neurodevelopmental defects, HCMV neuropathogenesis remains poorly understood. A major challenge for investigating HCMV-induced abnormal brain development is the strict CMV species specificity, which prevents the use of animal models to directly study brain defects caused by HCMV. We show that infection of human-induced pluripotent-stem-cell-derived brain organoids by a “clinical-like” HCMV strain results in reduced brain organoid growth, impaired formation of cortical layers, and abnormal calcium signaling and neural network activity. Moreover, we show that the impeded brain organoid development caused by HCMV can be prevented by neutralizing antibodies (NAbs) that recognize the HCMV pentamer complex. These results demonstrate in a three-dimensional cellular biosystem that HCMV can impair the development and function of the human brain and provide insights into the potential capacity of NAbs to mitigate brain defects resulted from HCMV infection. Human iPSC-derived brain organoids to model HCMV-induced brain malformation “Clinical-like” HCMV strain impairs human brain organoid growth and structure HCMV-infected brain organoids exhibit abnormal calcium signaling and neural network HCMV-induced brain organoid abnormality can be prevented by neutralizing antibodies
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Elste J, Kaltenbach D, Patel VR, Nguyen MT, Sharthiya H, Tandon R, Mehta SK, Volin MV, Fornaro M, Tiwari V, Desai UR. Inhibition of Human Cytomegalovirus Entry into Host Cells Through a Pleiotropic Small Molecule. Int J Mol Sci 2020; 21:ijms21051676. [PMID: 32121406 PMCID: PMC7084493 DOI: 10.3390/ijms21051676] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 02/19/2020] [Accepted: 02/26/2020] [Indexed: 12/11/2022] Open
Abstract
Human cytomegalovirus (HCMV) infections are wide-spread among the general population with manifestations ranging from asymptomatic to severe developmental disabilities in newborns and life-threatening illnesses in individuals with a compromised immune system. Nearly all current drugs suffer from one or more limitations, which emphasizes the critical need to develop new approaches and new molecules. We reasoned that a ‘poly-pharmacy’ approach relying on simultaneous binding to multiple receptors involved in HCMV entry into host cells could pave the way to a more effective therapeutic outcome. This work presents the study of a synthetic, small molecule displaying pleiotropicity of interactions as a competitive antagonist of viral or cell surface receptors including heparan sulfate proteoglycans and heparan sulfate-binding proteins, which play important roles in HCMV entry and spread. Sulfated pentagalloylglucoside (SPGG), a functional mimetic of heparan sulfate, inhibits HCMV entry into human foreskin fibroblasts and neuroepithelioma cells with high potency. At the same time, SPGG exhibits no toxicity at levels as high as 50-fold more than its inhibition potency. Interestingly, cell-ELISA assays showed downregulation in HCMV immediate-early gene 1 and 2 (IE 1&2) expression in presence of SPGG further supporting inhibition of viral entry. Finally, HCMV foci were observed to decrease significantly in the presence of SPGG suggesting impact on viral spread too. Overall, this work offers the first evidence that pleiotropicity, such as demonstrated by SPGG, may offer a new poly-therapeutic approach toward effective inhibition of HCMV.
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Affiliation(s)
- James Elste
- Department of Microbiology & Immunology, College of Graduate Studies and Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA; (J.E.); (V.R.P.); (M.T.N.); (M.V.V.)
| | - Dominik Kaltenbach
- Department of Biomedical Sciences, College of Graduate Studies, Midwestern University, Downers Grove, IL 60515, USA;
| | - Vraj R. Patel
- Department of Microbiology & Immunology, College of Graduate Studies and Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA; (J.E.); (V.R.P.); (M.T.N.); (M.V.V.)
| | - Max T. Nguyen
- Department of Microbiology & Immunology, College of Graduate Studies and Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA; (J.E.); (V.R.P.); (M.T.N.); (M.V.V.)
| | - Harsh Sharthiya
- Department of Anatomy, College of Graduate Studies and Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA; (H.S.); (M.F.)
| | - Ritesh Tandon
- Department of Microbiology and Immunology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216, USA;
| | | | - Michael V. Volin
- Department of Microbiology & Immunology, College of Graduate Studies and Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA; (J.E.); (V.R.P.); (M.T.N.); (M.V.V.)
| | - Michele Fornaro
- Department of Anatomy, College of Graduate Studies and Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA; (H.S.); (M.F.)
| | - Vaibhav Tiwari
- Department of Microbiology & Immunology, College of Graduate Studies and Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA; (J.E.); (V.R.P.); (M.T.N.); (M.V.V.)
- Correspondence: (V.T.); (U.R.D.)
| | - Umesh R. Desai
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23298, USA
- Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, VA 23219, USA
- Correspondence: (V.T.); (U.R.D.)
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Choi KY, El-Hamdi NS, McGregor A. Requirements for guinea pig cytomegalovirus tropism and antibody neutralization on placental amniotic sac cells. J Gen Virol 2020; 101:426-439. [PMID: 32068527 DOI: 10.1099/jgv.0.001394] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Congenital cytomegalovirus (cCMV) is a leading cause of birth defects. The guinea pig is the only small cCMV animal model. Guinea pig cytomegalovirus (GPCMV) encodes similar glycoprotein complexes to human CMV (HCMV) including gB and the gH-based pentamer complex (PC). In HCMV, both gB and PC are neutralizing antibody antigens. The relevance of GPCMV PC for virus tropism and vaccine target remains controversial. A novel guinea pig placental amniotic sac epithelial (GPASE) cell-line did not express viral cell receptor platelet derived growth factor receptor alpha (PDGFRA) and resulted in requirement for the PC for GPCMV infection unless PDGFRA was ectopically expressed. High titer anti-gB sera from a GPCMV gB vaccine study was evaluated for GPCMV neutralizing capability on GPASE cells in comparison to convalescent sera from GPCMV(PC+) or GPCMV(PC-) infected animals. Anti-gB sera neutralized fibroblast infection but was less effective compared to anti-GPCMV(PC-), which had antibodies to gH/gL. However, both anti-GPCMV(PC-) and anti-gB sera similarly had reduced neutralizing capability on GPASE and renal epithelial cells in comparison to anti-GPCMV(PC+) sera, which had additional antibodies to PC. Overall, results demonstrate the importance of the PC for GPCMV tropism to various cell types that lack PDGFRA expression and the limited ability of anti-gB sera to neutralize GPCMV on non-fibroblast cells despite the essential nature of gB glycoprotein.
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Affiliation(s)
- K Yeon Choi
- Department of Microbial Pathogenesis & Immunology, College of Medicine, Texas A&M University, Bryan, TX, USA
| | - Nadia S El-Hamdi
- Department of Microbial Pathogenesis & Immunology, College of Medicine, Texas A&M University, Bryan, TX, USA
| | - Alistair McGregor
- Department of Microbial Pathogenesis & Immunology, College of Medicine, Texas A&M University, Bryan, TX, USA
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Neutralizing antibodies to gB based CMV vaccine requires full length antigen but reduced virus neutralization on non-fibroblast cells limits vaccine efficacy in the guinea pig model. Vaccine 2020; 38:2340-2349. [PMID: 32008881 DOI: 10.1016/j.vaccine.2020.01.063] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 01/15/2020] [Accepted: 01/21/2020] [Indexed: 12/18/2022]
Abstract
Cytomegalovirus is a leading cause of congenital disease and a vaccine is a high priority. The viral gB glycoprotein is essential for infection on all cell types. The guinea pig is the only small animal model for congenital CMV (cCMV), but requires guinea pig cytomegalovirus (GPCMV). Various GPCMV gB vaccine strategies have been investigated but not with a full length protein. Previous GPCMV gB vaccines have failed to fully protect against cCMV, with approximately 50% efficacy. In an effort to define the basis of GPCMV gB based vaccine failure, we evaluated recombinant defective Ad vectors encoding GPCMV gB full length (gBwt), or truncated protein lacking transmembrane domain (gBTMD). Both candidate vaccines evoked high anti-gB titers and neutralized virus infection on fibroblast cells but had varying weaker results on non-fibroblasts (renal epithelial and placental trophoblasts). Non-fibroblast cells are dependent upon the viral pentamer complex (PC) for endocytic pathway cell entry. In contrast, fibroblasts cells that express the viral receptor platelet derived growth factor receptor alpha (PDGFRA) to enable entry by direct cell fusion independent of the PC. Anti-gBwt sera was approximately 2-fold (renal epithelial) to 3-fold (fibroblasts) more effective at neutralizing virus compared to anti-gBTMD sera. Both gB vaccines were weakest against virus neutralization on trophoblasts. Knockout of PDGFRA cell receptor on fibroblast cells (GPKO) rendered virus dependent upon the PC pathway for cell entry and anti-gB GPCMV NA50 was more similar to epithelial cells. In a gBwt vaccine protection study, vaccination of animals significantly reduced, but did not prevent dissemination of wild type GPCMV challenge virus to target organs. Depletion of complement in vivo had limited impact on vaccine efficacy. Overall, a full length gB antigen has the potential to improve neutralizing antibody titer but fails to fully prevent virus dissemination and likely congenital infection.
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31
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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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32
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Paradowska E, Jabłońska A, Studzińska M, Kasztelewicz B, Wiśniewska-Ligier M, Dzierżanowska-Fangrat K, Woźniakowska-Gęsicka T, Czech-Kowalska J. Distribution of the CMV glycoprotein gH/gL/gO and gH/gL/pUL128/pUL130/pUL131A complex variants and associated clinical manifestations in infants infected congenitally or postnatally. Sci Rep 2019; 9:16352. [PMID: 31705022 PMCID: PMC6841705 DOI: 10.1038/s41598-019-52906-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 10/22/2019] [Indexed: 11/09/2022] Open
Abstract
Human cytomegalovirus (CMV) is a major cause of morbidity in fetuses following intrauterine infection. The glycoprotein (g) envelope trimeric gH/gL/gO and pentameric gH/gL/pUL128/pUL130/pUL131A complexes are required for CMV entry into fibroblasts and endothelial/epithelial cells, respectively, and both are targets for neutralizing antibodies. The role of sequence variability among viral strains in the outcome of congenital CMV infection is controversial. Variation in the CMV UL75 gene encoding glycoprotein H (gH), the UL115 (gL), the UL74 (gO), and the UL128 locus (UL128L) encoding three structural proteins (pUL128, pUL130, and pUL131A) was determined in 82 newborns with congenital CMV infection and 113 infants with postnatal or unproven congenital CMV infection. Genotyping was performed by sequencing analysis of PCR-amplified fragments and the PCR-restriction fragment length polymorphism (RFLP) method, and the viral load was measured by quantitative real-time PCR. The obtained results demonstrated that (1) different CMV variants and mixed CMV infections can be detected in newborns infected congenitally; (2) the gH1 genotype, UL130 variant 6, and UL131A variant 1 were associated with some signs/symptoms within cohort of pediatric patients, mainly consisting of infants with symptomatic CMV infection. The results revealed that pUL130, pUL131A, and gH polymorphisms seemed to be associated with the outcome of CMV infection in infants.
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Affiliation(s)
- Edyta Paradowska
- Laboratory of Virology, Institute of Medical Biology, Polish Academy of Sciences, Lodz, Poland.
| | - Agnieszka Jabłońska
- Laboratory of Virology, Institute of Medical Biology, Polish Academy of Sciences, Lodz, Poland
| | - Mirosława Studzińska
- Laboratory of Virology, Institute of Medical Biology, Polish Academy of Sciences, Lodz, Poland
| | - Beata Kasztelewicz
- Department of Clinical Microbiology and Immunology, The Children's Memorial Health Institute, Warsaw, Poland
| | - Małgorzata Wiśniewska-Ligier
- Department of Pediatrics, Immunology, and Nephrology, Polish Mother's Memorial Hospital Research Institute, Lodz, Poland
- 3rd Department of Pediatrics, Polish Mother's Memorial Hospital Research Institute, Lodz, Poland
| | | | | | - Justyna Czech-Kowalska
- Department of Neonatology and Neonatal Intensive Care, The Children's Memorial Health Institute, Warsaw, Poland
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Li X, Zhang Y, Jing L, Fu Z, Ma O, Ganguly J, Vaidya N, Sisson R, Naginskaya J, Chinthala A, Cui M, Yamagata R, Wilson M, Sanders M, Wang Z, Lo Surdo P, Bugno M. Integration of high-throughput analytics and cell imaging enables direct early productivity and product quality assessment during Chinese Hamster ovary cell line development for a complex multi-subunit vaccine antigen. Biotechnol Prog 2019; 36:e2914. [PMID: 31568688 DOI: 10.1002/btpr.2914] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 08/14/2019] [Accepted: 09/11/2019] [Indexed: 12/19/2022]
Abstract
Mammalian cell line generation typically includes stable pool generation, single cell cloning and several rounds of clone selection based on cell growth, productivity and product quality criteria. Individual clone expansion and phenotype-based ranking is performed initially for hundreds or thousands of mini-scale cultures, representing the major operational challenge during cell line development. Automated cell culture and analytics systems have been developed to enable high complexity clone selection workflows; while ensuring traceability, safety, and quality of cell lines intended for biopharmaceutical applications. Here we show that comprehensive and quantitative assessment of cell growth, productivity, and product quality attributes are feasible at the 200-1,200 cell colony stage, within 14 days of the single cell cloning in static 96-well plate culture. The early cell line characterization performed prior to the clone expansion in suspension culture can be used for a single-step, direct selection of high quality clones. Such clones were comparable, both in terms of productivity and critical quality attributes (CQAs), to the top-ranked clones identified using an established iterative clone screening approach. Using a complex, multi-subunit antigen as a model protein, we observed stable CQA profiles independently of the cell culture format during the clonal expansion as well as in the batch and fed-batch processes. In conclusion, we propose an accelerated clone selection approach that can be readily incorporated into various cell line development workstreams, leading to significant reduction of the project timelines and resource requirements.
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Affiliation(s)
- Xiangming Li
- GSK, US Technical R&D, Drug Substance, Rockville, Maryland
| | - Yujian Zhang
- GSK, US Technical R&D, Drug Substance, Rockville, Maryland
| | - Li Jing
- GSK, US Technical R&D, Drug Substance, Rockville, Maryland
| | - Zongming Fu
- GSK, US Technical R&D, Analytical Research and Development, Rockville, Maryland
| | - Ou Ma
- GSK, US Technical R&D, Drug Substance, Rockville, Maryland
| | - Jishna Ganguly
- GSK, US Technical R&D, Drug Substance, Rockville, Maryland
| | - Nilesh Vaidya
- GSK, US Technical R&D, Drug Substance, Rockville, Maryland
| | - Richard Sisson
- GSK, US Technical R&D, Drug Substance, Rockville, Maryland
| | | | | | - Minggang Cui
- GSK, US Technical R&D, CMC Statistical Sciences, Rockville, Maryland
| | - Ryan Yamagata
- GSK, US Technical R&D, CMC Statistical Sciences, Rockville, Maryland
| | - Mark Wilson
- GSK, US Technical R&D, Drug Substance, Rockville, Maryland
| | | | - Zihao Wang
- GSK, US Technical R&D, Analytical Research and Development, Rockville, Maryland
| | - Paola Lo Surdo
- GSK, US Technical R&D, Drug Substance, Rockville, Maryland
| | - Marcin Bugno
- GSK, US Technical R&D, Drug Substance, Rockville, Maryland
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Inclusion of the Viral Pentamer Complex in a Vaccine Design Greatly Improves Protection against Congenital Cytomegalovirus in the Guinea Pig Model. J Virol 2019; 93:JVI.01442-19. [PMID: 31484753 DOI: 10.1128/jvi.01442-19] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 08/27/2019] [Indexed: 12/11/2022] Open
Abstract
A vaccine against congenital cytomegalovirus (cCMV) is a high priority. The guinea pig is a small-animal model for cCMV. A disabled infectious single-cycle (DISC) viral vaccine strain based on a guinea pig cytomegalovirus (GPCMV) capsid mutant was evaluated. A previous version of this vaccine did not express the gH/gL-based pentamer complex (PC) and failed to fully protect against cCMV. The PC is necessary for GPCMV epithelial cell/trophoblast tropism and congenital infection and is a potentially important neutralizing antigen. Here, we show that a second-generation PC-positive (PC+) DISC (DISCII) vaccine induces neutralizing antibodies to the PC and other glycoproteins and a cell-mediated response to pp65 (GP83). Additionally, a CRISPR/Cas9 strategy identified guinea pig platelet-derived growth factor receptor alpha (PDGFRA) to be the receptor for PC-independent infection of fibroblast cells. Importantly, PDGFRA was absent in epithelial and trophoblast cells, which were dependent upon the viral PC for infection. Virus neutralization by DISCII antibodies on epithelial and trophoblast cells was similar to that in sera from wild-type virus-infected animals and dependent in part on PC-specific antibodies. In contrast, sera from PC-negative virus-infected animals poorly neutralized virus on non-fibroblast cells. DISCII-vaccinated animals were protected against congenital infection, in contrast to a nonvaccinated group. The target organs of pups in the vaccine group were negative for wild-type virus, unlike those of pups in the control group, with GPCMV transmission being approximately 80%. Overall, the DISCII vaccine had 97% efficacy against cCMV. The complete protection provided by this PC+ DISC vaccine makes the possibility of the use of this approach against human cCMV attractive.IMPORTANCE Cytomegalovirus (CMV) is a leading cause of congenital disease in newborns, and an effective vaccine remains an elusive goal. The guinea pig is the only small-animal model for cCMV. Guinea pig cytomegalovirus (GPCMV) encodes a glycoprotein pentamer complex (PC) for entry into non-fibroblast cells, including placental trophoblasts, to enable cCMV. As with human cytomegalovirus (HCMV), GPCMV uses a specific cell receptor (PDGFRA) for fibroblast entry, but other receptors are required for non-fibroblast cells. A disabled infectious single-cycle (DISC) GPCMV vaccine strain induced an antibody immune response to the viral pentamer to enhance virus neutralization on non-fibroblast cells, and vaccinated animals were fully protected against cCMV. Inclusion of the PC as part of a vaccine design dramatically improved vaccine efficacy, and this finding underlines the importance of the immune response to the PC in contributing toward protection against cCMV. This vaccine represents an important milestone in the development of a vaccine against cCMV.
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35
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Human Cytomegalovirus Cell Tropism and Host Cell Receptors. Vaccines (Basel) 2019; 7:vaccines7030070. [PMID: 31336680 PMCID: PMC6789482 DOI: 10.3390/vaccines7030070] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 07/16/2019] [Accepted: 07/17/2019] [Indexed: 12/11/2022] Open
Abstract
In the 1970s–1980s, a striking increase in the number of disseminated human cytomegalovirus (HCMV) infections occurred in immunosuppressed patient populations. Autopsy findings documented the in vivo disseminated infection (besides fibroblasts) of epithelial cells, endothelial cells, and polymorphonuclear leukocytes. As a result, multiple diagnostic assays, such as quantification of HCMV antigenemia (pp65), viremia (infectious virus), and DNAemia (HCMV DNA) in patient blood, were developed. In vitro experiments showed that only low passage or endothelial cell-passaged clinical isolates, and not laboratory-adapted strains, could reproduce both HCMV leuko- and endothelial cell-tropism, which were found through genetic analysis to require the three viral genes UL128, UL130, and UL131 of the HCMV UL128 locus (UL128L). Products of this locus, together with gH/gL, were shown to form the gH/gL/pUL128L pentamer complex (PC) required for infection of epithelial cells/endothelial cells, whereas gH/gL and gO form the gH/gL/gO trimer complex (TC) required for infection of all cell types. In 2016, following previous work, a receptor for the TC that mediates entry into fibroblasts was identified as PDGFRα, while in 2018, a receptor for the PC that mediates entry into endothelial/epithelial cells was identified as neuropilin2 (Nrp2). Furthermore, the olfactory receptor family member OR14I1 was recently identified as a possible additional receptor for the PC in epithelial cells. Thus, current data support two models of viral entry: (i) in fibroblasts, following interaction of PDGFRα with TC, the latter activates gB to fuse the virus envelope with the cell membrane, whereas (ii) in epithelial cells/endothelial cells, interaction of Nrp2 (and OR14I1) with PC promotes endocytosis of virus particles, followed by gB activation by gH/gL/gO (or gH/gL) and final low-pH entry into the cell.
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Abstract
In this chapter, we present an overview on betaherpesvirus entry, with a focus on human cytomegalovirus, human herpesvirus 6A and human herpesvirus 6B. Human cytomegalovirus (HCMV) is a complex human pathogen with a genome of 235kb encoding more than 200 genes. It infects a broad range of cell types by switching its viral ligand on the virion, using the trimer gH/gL/gO for infection of fibroblasts and the pentamer gH/gL/UL128/UL130/UL131 for infection of other cells such as epithelial and endothelial cells, leading to membrane fusion mediated by the fusion protein gB. Adding to this scenario, however, accumulating data reveal the actual complexity in the viral entry process of HCMV with an intricate interplay among viral and host factors. Key novel findings include the identification of entry receptors platelet-derived growth factor-α receptor (PDGFRα) and Netropilin-2 (Nrp2) for trimer and pentamer, respectively, the determination of atomic structures of the fusion protein gB and the pentamer, and the in situ visualization of the state and arrangement of functional glycoproteins on virion. This is covered in the first part of this review. The second part focusses on HHV-6 which is a T lymphotropic virus categorized as two distinct virus species, HHV-6A and HHV-6B based on differences in epidemiological, biological, and immunological aspects, although homology of their entire genome sequences is nearly 90%. HHV-6B is a causative agent of exanthema subitum (ES), but the role of HHV-6A is unknown. HHV-6B reactivation occasionally causes encephalitis in patients with hematopoietic stem cell transplant. The HHV-6 specific envelope glycoprotein complex, gH/gL/gQ1/gQ2 is a viral ligand for the entry receptor. Recently, each virus has been found to recognize a different cellular receptor, CD46 for HHV 6A amd CD134 for HHV 6B. These findings show that distinct receptor recognition differing between both viruses could explain their different pathogenesis.
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Affiliation(s)
- Mitsuhiro Nishimura
- Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Yasuko Mori
- Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe, Japan.
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The N Terminus of Human Cytomegalovirus Glycoprotein O Is Important for Binding to the Cellular Receptor PDGFRα. J Virol 2019; 93:JVI.00138-19. [PMID: 30894468 DOI: 10.1128/jvi.00138-19] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 01/28/2019] [Indexed: 02/07/2023] Open
Abstract
The human cytomegalovirus (HCMV) glycoprotein complex gH/gL/gO is required for the infection of cells by cell-free virions. It was recently shown that entry into fibroblasts depends on the interaction of gO with the platelet-derived growth factor receptor alpha (PDGFRα). This interaction can be blocked with soluble PDGFRα-Fc, which binds to HCMV virions and inhibits entry. The aim of this study was to identify parts of gO that contribute to PDGFRα binding. In a systematic mutational approach, we targeted potential interaction sites by exchanging conserved clusters of charged amino acids of gO with alanines. To screen for impaired interaction with PDGFRα, virus mutants were tested for sensitivity to inhibition by soluble PDGFRα-Fc. Two mutants with mutations within the N terminus of gO (amino acids 56 to 61 and 117 to 121) were partially resistant to neutralization. To validate whether these mutations impair interaction with PDGFRα-Fc, we compared binding of PDGFRα-Fc to mutant and wild-type virions via quantitative immunofluorescence analysis. PDGFRα-Fc staining intensities were reduced by 30% to 60% with mutant virus particles compared to wild-type particles. In concordance with the reduced binding to the soluble receptor, virus penetration into fibroblasts, which relies on binding to the cellular PDGFRα, was also reduced. In contrast, PDGFRα-independent penetration into endothelial cells was unaltered, demonstrating that the phenotypes of the gO mutant viruses were specific for the interaction with PDGFRα. In conclusion, the mutational screening of gO revealed that the N terminus of gO contributes to efficient spread in fibroblasts by promoting the interaction of virions with its cellular receptor.IMPORTANCE The human cytomegalovirus is a highly prevalent pathogen that can cause severe disease in immunocompromised hosts. Currently used drugs successfully target the viral replication within the host cell, but their use is restricted due to side effects and the development of resistance. An alternative approach is the inhibition of virus entry, for which understanding the details of the initial virus-cell interaction is desirable. As binding of the viral gH/gL/gO complex to the cellular PDGFRα drives infection of fibroblasts, this is a potential target for inhibition of infection. Our mutational mapping approach suggests the N terminus as the receptor binding portion of the protein. The respective mutants were partially resistant to inhibition by PDGFRα-Fc but also attenuated for infection of fibroblasts, indicating that such mutations have little if any benefit for the virus. These findings highlight the potential of targeting the interaction of gH/gL/gO with PDGFRα for therapeutic inhibition of HCMV.
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Foglierini M, Marcandalli J, Perez L. HCMV Envelope Glycoprotein Diversity Demystified. Front Microbiol 2019; 10:1005. [PMID: 31156572 PMCID: PMC6529531 DOI: 10.3389/fmicb.2019.01005] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 04/18/2019] [Indexed: 12/27/2022] Open
Abstract
Human cytomegalovirus (HCMV) is the leading viral cause of congenital birth defects and is responsible for morbidity and mortality in immunosuppressed individuals. Considerable efforts have been deployed over the last decade to develop a vaccine capable of preventing HCMV infection. However, in recent clinical trials, vaccines showed at best modest efficacy in preventing infection. These findings might be explained by the high level of sequence polymorphism at the genomic level. To investigate if genomic variation also leads to antigenic variation, we performed a bioinformatic sequence analysis and evaluated the percentage of conservation at the amino acid level of all the proteins present in the virion envelope. Using more than two hundred sequences per envelope glycoprotein and analyzing their degree of conservation, we observe that antigenic variation is in large part limited to three proteins. In addition, we demonstrate that the two leading vaccine candidates, the pentamer and gB complexes, are well conserved at the amino acid level. These results suggest that despite genomic polymorphism, antigenic variability is not involved in the modest efficacy observed in the recent clinical trials for a HCMV vaccine. We therefore propose that next-generation vaccines should focus on stabilizing and refining the gB domains needed to induce a protective humoral response.
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Affiliation(s)
- Mathilde Foglierini
- Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera Italiana, Bellinzona, Switzerland.,Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Jessica Marcandalli
- Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera Italiana, Bellinzona, Switzerland
| | - Laurent Perez
- Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera Italiana, Bellinzona, Switzerland
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Restriction of Human Cytomegalovirus Infection by Galectin-9. J Virol 2019; 93:JVI.01746-18. [PMID: 30487283 DOI: 10.1128/jvi.01746-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 10/31/2018] [Indexed: 12/24/2022] Open
Abstract
Human cytomegalovirus (HCMV) is a ubiquitous human herpesvirus. While HCMV infection is generally asymptomatic in the immunocompetent, it can have devastating consequences in those with compromised or underdeveloped immune systems, including transplant recipients and neonates. Galectins are a widely expressed protein family that have been demonstrated to modulate both antiviral immunity and regulate direct host-virus interactions. The potential for galectins to directly modulate HCMV infection has not previously been studied, and our results reveal that galectin-9 (Gal-9) can potently inhibit HCMV infection. Gal-9-mediated inhibition of HCMV was dependent upon its carbohydrate recognition domains and thus dependent on glycan interactions. Temperature shift studies revealed that Gal-9 specific inhibition was mediated primarily at the level of virus-cell fusion and not binding. Additionally, we found that during reactivation of HCMV in hematopoietic stem cell transplant (HSCT) patients soluble Gal-9 is upregulated. This study provides the first evidence for Gal-9 functioning as a potent antiviral defense effector molecule against HCMV infection and identifies it as a potential clinical candidate to restrict HCMV infections.IMPORTANCE Human cytomegalovirus (HCMV) continues to cause serious and often life-threatening disease in those with impaired or underdeveloped immune systems. This virus is able to infect and replicate in a wide range of human cell types, which enables the virus to spread to other individuals in a number of settings. Current antiviral drugs are associated with a significant toxicity profile, and there is no vaccine; these factors highlight a need to identify additional targets for the development of anti-HCMV therapies. We demonstrate for the first time that secretion of a member of the galectin family of proteins, galectin-9 (Gal-9), is upregulated during natural HCMV-reactivated infection and that this soluble cellular protein possesses a potent capacity to block HCMV infection by inhibiting virus entry into the host cell. Our findings support the possibility of harnessing the antiviral properties of Gal-9 to prevent HCMV infection and disease.
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Liu J, Jardetzky TS, Chin AL, Johnson DC, Vanarsdall AL. The Human Cytomegalovirus Trimer and Pentamer Promote Sequential Steps in Entry into Epithelial and Endothelial Cells at Cell Surfaces and Endosomes. J Virol 2018; 92:e01336-18. [PMID: 30111564 PMCID: PMC6189492 DOI: 10.1128/jvi.01336-18] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 08/08/2018] [Indexed: 12/23/2022] Open
Abstract
Human cytomegalovirus (HCMV) infects a wide variety of human cell types by different entry pathways that involve distinct envelope glycoprotein complexes that include gH/gL, a trimer complex consisting of gHgL/gO, and a pentamer complex consisting of gH/gL/UL128/UL130/UL131. We characterized the effects of soluble forms of these proteins on HCMV entry. Soluble trimer and pentamer blocked entry of HCMV into epithelial and endothelial cells, whereas soluble gH/gL did not. Trimer inhibited HCMV entry into fibroblast cells, but pentamer and gH/gL did not. Both trimer and pentamer bound to the surfaces of fibroblasts and epithelial cells, whereas gH/gL did not bind to either cell type. Cell surface binding of trimer and pentamer did not involve heparin sulfate moieties. The ability of soluble trimer to block entry of HCMV into epithelial cells did not involve platelet-derived growth factor PDGFRα, which has been reported as a trimer receptor for fibroblasts. Soluble trimer reduced the amount of virus particles that could be adsorbed onto the surface of epithelial cells, whereas soluble pentamer had no effect on virus adsorption. However, soluble pentamer reduced the ability of virus particles to exit from early endosomes into the cytoplasm and then travel to the nucleus. These studies support a model in which both the trimer and pentamer are required for HCMV entry into epithelial and endothelial cells, with trimer interacting with cell surface receptors other than PDGFR and pentamer acting later in the entry pathway to promote egress from endosomes.IMPORTANCE HCMV infects nearly 80% of the world's population and causes significant morbidity and mortality. The current antiviral agents used to treat HCMV infections are prone to resistance and can be toxic to patients, and there is no current vaccine against HCMV available. The data in this report will lead to a better understanding of how essential HCMV envelope glycoproteins function during infection of biologically important cell types and will have significant implications for understanding HCMV pathogenesis for developing new therapeutics.
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Affiliation(s)
- Jing Liu
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California, USA
| | - Ted S Jardetzky
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California, USA
| | - Andrea L Chin
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, Oregon, USA
| | - David C Johnson
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, Oregon, USA
| | - Adam L Vanarsdall
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, Oregon, USA
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Diamond DJ, LaRosa C, Chiuppesi F, Contreras H, Dadwal S, Wussow F, Bautista S, Nakamura R, Zaia JA. A fifty-year odyssey: prospects for a cytomegalovirus vaccine in transplant and congenital infection. Expert Rev Vaccines 2018; 17:889-911. [PMID: 30246580 PMCID: PMC6343505 DOI: 10.1080/14760584.2018.1526085] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 09/17/2018] [Indexed: 02/08/2023]
Abstract
INTRODUCTION It has been almost fifty years since the Towne strain was used by Plotkin and collaborators as the first vaccine candidate for cytomegalovirus (CMV). While that approach showed partial efficacy, there have been a multitude of challenges to improve on the promise of a CMV vaccine. Efforts have been dichotomized into a therapeutic vaccine for patients with CMV-infected allografts, either stem cells or solid organ, and a prophylactic vaccine for congenital infection. AREAS COVERED This review will evaluate research prospects for a therapeutic vaccine for transplant recipients that recognizes CMV utilizing primarily T cell responses. Similarly, we will provide an extensive discussion on attempts to develop a vaccine to prevent the manifestations of congenital infection, based on eliciting a humoral anti-CMV protective response. The review will also describe newer developments that have upended the efforts toward such a vaccine through the discovery of a second pathway of CMV infection that utilizes an alternative receptor for entry using a series of antigens that have been determined to be important for prevention of infection. EXPERT COMMENTARY There is a concerted effort to unify separate therapeutic and prophylactic vaccine strategies into a single delivery agent that would be effective for both transplant-related and congenital infection.
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Affiliation(s)
- Don J. Diamond
- Department of Experimental Therapeutics, Beckman Research
Institute of City of Hope, Duarte, CA
| | - Corinna LaRosa
- Department of Experimental Therapeutics, Beckman Research
Institute of City of Hope, Duarte, CA
| | - Flavia Chiuppesi
- Department of Experimental Therapeutics, Beckman Research
Institute of City of Hope, Duarte, CA
| | - Heidi Contreras
- Department of Experimental Therapeutics, Beckman Research
Institute of City of Hope, Duarte, CA
| | - Sanjeet Dadwal
- Department of Medical Specialties, City of Hope National
Medical Center, Duarte, CA
| | - Felix Wussow
- Department of Experimental Therapeutics, Beckman Research
Institute of City of Hope, Duarte, CA
| | - Supriya Bautista
- Department of Experimental Therapeutics, Beckman Research
Institute of City of Hope, Duarte, CA
| | - Ryotaro Nakamura
- Department of Hematology & Hematopoetic Cell
Transplantation, City of Hope National Medical Center, Duarte, CA
| | - John A. Zaia
- Center for Gene Therapy, Hematological Malignancy and Stem
Cell Transplantation Institute, City of Hope, Duarte, CA
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Infection of endotheliotropic human cytomegalovirus of trabecular meshwork cells. Jpn J Ophthalmol 2018; 62:667-676. [PMID: 30191418 DOI: 10.1007/s10384-018-0618-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 08/06/2018] [Indexed: 12/27/2022]
Abstract
PURPOSE Human cytomegalovirus (HCMV) infections can cause endotheliitis which is associated with an elevation in the intraocular pressure (IOP). However, the mechanism of the IOP elevation has not been established. The purpose of this study was to determine whether HCMV strains which are capable of infecting corneal endothelial cells can also replicate and induce anti-viral responses, and can reorganize the actin cytoskeleton in trabecular meshwork cells. STUDY DESIGN Experimental study design. METHODS Cultured primary human trabecular meshwork cells (HTMCs) were infected with the Towne or TB40/E strains of HCMV. TB40/E is trophic for vascular endothelial and corneal endothelial cells. Real-time PCR, western blot, and fluorescent immunostaining have been used to determine whether HCMV-infected HTMCs will support the expression of viral mRNA and protein, allow viral replication, and elicit anti-viral host responses. We also determined whether lytic replication was present after HCMV infection. RESULTS HCMV infection led to the expression of viral mRNA and proteins of IE1, glycoprotein B(gB), and pp65. TB40/E infection induced interferon-β, a sign of host anti-viral immune response and monocyte chemotactic protein-1 (MCP-1) as IOP-related chemokine. Together with the induction of the regulators of actin cytoskeleton, myosin phosphatase Rho interacting protein (MPRIP) and MCP-1, TB40/E induced a high level of expression of viral proteins, including IE1, gB, and pp65 as well as actin stress fiber formation, and achieved pathogenically high viral titers. CONCLUSIONS Human trabecular meshwork cells support the replication of endotheliotropic TB40/E strain of HCMV which indicates that this strain may have high virulence for trabecular meshwork.
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The transcriptome of human mammary epithelial cells infected with the HCMV-DB strain displays oncogenic traits. Sci Rep 2018; 8:12574. [PMID: 30135434 PMCID: PMC6105607 DOI: 10.1038/s41598-018-30109-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 07/21/2018] [Indexed: 12/13/2022] Open
Abstract
Increasing evidence indicates that human cytomegalovirus (HCMV) populations under the influence of host environment, can either be stable or rapidly differentiating, leading to tissue compartment colonization. We isolated previously from a 30-years old pregnant woman, a clinical isolate of HCMV, that we refered to as the HCMV-DB strain (accession number KT959235). The HCMV-DB clinical isolate demonstrated its ability to infect primary macrophages and to upregulate the proto-oncogene Bcl-3. We observed in this study that the genome of HCMV-DB strain is close to the genomes of other primary clinical isolates including the Toledo and the JP strains with the later having been isolated from a glandular tissue, the prostate. Using a phylogenetic analysis to compare the genes involved in virus entry, we observed that the HCMV-DB strain is close to the HCMV strain Merlin, the prototype HCMV strain. HCMV-DB infects human mammary epithelial cells (HMECs) which in turn display a ER−/PR−/HER2− phenotype, commonly refered to as triple negative. The transcriptome of HCMV-DB-infected HMECs presents the characteristics of a pro-oncogenic cellular environment with upregulated expression of numerous oncogenes, enhanced activation of pro-survival genes, and upregulated markers of cell proliferation, stemcellness and epithelial mesenchymal transition (EMT) that was confirmed by enhanced cellular proliferation and tumorsphere formation in vitro. Taken together our data indicate that some clinical isolates could be well adapted to the mammary tissue environment, as it is the case for the HCMV-DB strain. This could influence the viral fitness, ultimately leading to breast cancer development.
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From recognition to execution-the HCMV Pentamer from receptor binding to fusion triggering. Curr Opin Virol 2018; 31:43-51. [PMID: 29866439 DOI: 10.1016/j.coviro.2018.05.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 05/07/2018] [Accepted: 05/11/2018] [Indexed: 01/17/2023]
Abstract
The β-herpesvirus human cytomegalovirus (HCMV) is the leading viral cause of neonatal developmental disabilities. In HCMV, the conserved herpesvirus glycoprotein B (gB) mediates membrane fusion between the viral and host cell membranes, whereas the trimeric gH/gL/gO or the pentameric gH/gL/UL128/UL130/UL31A complexes (Pentamer) bind to cell-specific receptors and provide the triggering signal to gB. Recent structural and functional studies have provided new insights into Pentamer structure, conformational flexibility, location of epitopes for neutralizing antibodies and potential binding sites for cell surface receptors. Together, these data suggest a model where receptor binding triggers a conformational change in Pentamer, allowing it to interact with gB and initiate the membrane fusion process.
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CD147 Promotes Entry of Pentamer-Expressing Human Cytomegalovirus into Epithelial and Endothelial Cells. mBio 2018; 9:mBio.00781-18. [PMID: 29739904 PMCID: PMC5941078 DOI: 10.1128/mbio.00781-18] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Human cytomegalovirus (HCMV) replicates in many diverse cell types in vivo, and entry into different cells involves distinct entry mechanisms and different envelope glycoproteins. HCMV glycoprotein gB is thought to act as the virus fusogen, apparently after being triggered by different gH/gL proteins that bind distinct cellular receptors or entry mediators. A trimer of gH/gL/gO is required for entry into all cell types, and entry into fibroblasts involves trimer binding to platelet-derived growth factor receptor alpha (PDGFRα). HCMV entry into biologically relevant epithelial and endothelial cells and monocyte-macrophages also requires a pentamer, gH/gL complexed with UL128, UL130, and UL131, and there is evidence that the pentamer binds unidentified receptors. We screened an epithelial cell cDNA library and identified the cell surface protein CD147, which increased entry of pentamer-expressing HCMV into HeLa cells but not entry of HCMV that lacked the pentamer. A panel of CD147-specific monoclonal antibodies inhibited HCMV entry into epithelial and endothelial cells, but not entry into fibroblasts. shRNA silencing of CD147 in endothelial cells inhibited HCMV entry but not entry into fibroblasts. CD147 colocalized with HCMV particles on cell surfaces and in endosomes. CD147 also promoted cell-cell fusion induced by expression of pentamer and gB in epithelial cells. However, soluble CD147 did not block HCMV entry and trimer and pentamer did not bind directly to CD147, supporting the hypothesis that CD147 acts indirectly through other proteins. CD147 represents the first HCMV entry mediator that specifically functions to promote entry of pentamer-expressing HCMV into epithelial and endothelial cells.IMPORTANCE Human cytomegalovirus infects nearly 80% of the world's population and causes significant morbidity and mortality. The current method of treatment involves the use of antiviral agents that are prone to resistance and can be highly toxic to patients; currently, there is no vaccine against HCMV available. HCMV infections involve virus dissemination throughout the body, infecting a wide variety of tissues; however, the mechanism of spread is not well understood, particularly with regard to which cellular proteins are utilized by HCMV to establish infection. This report describes the characterization of a newly identified cellular molecule that affects HCMV entry into epithelial and endothelial cells. These results will lead to a better understanding of HCMV pathogenesis and have implications for the development of future therapeutics.
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Wussow F, Chiuppesi F, Contreras H, Diamond DJ. Neutralization of Human Cytomegalovirus Entry into Fibroblasts and Epithelial Cells. Vaccines (Basel) 2017; 5:E39. [PMID: 29088098 PMCID: PMC5748606 DOI: 10.3390/vaccines5040039] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 10/26/2017] [Accepted: 10/27/2017] [Indexed: 12/12/2022] Open
Abstract
Human cytomegalovirus (HCMV) is a leading cause of permanent birth defects, highlighting the need to develop an HCMV vaccine candidate. However, HCMV vaccine development is complicated by the varying capacity of neutralizing antibodies (NAb) to interfere in vitro with the HCMV entry routes mediating infection of fibroblast (FB) and epithelial cells (EC). While HCMV infection of FB and EC requires glycoprotein complexes composed of gB and gH/gL/gO, EC infection depends additionally on the envelope pentamer complex (PC) composed of gH, gL, UL128, UL130 and UL131A. Unlike NAb to gB or gH epitopes that can interfere with both FB and EC infection, NAb targeting predominantly conformational epitopes of the UL128/130/131A subunits are unable to prevent FB entry, though they are highly potent in blocking EC infection. Despite the selective requirement of the PC for EC entry, the PC is exceptionally immunogenic as vaccine antigen to stimulate both EC- and FB-specific NAb responses due to its capacity to elicit NAb that target epitopes of the UL128/130/131A subunits and gH. These findings suggest that the PC could be sufficient in a subunit vaccine formulation to induce robust FB- and EC-specific NAb responses. In this short review, we discuss NAb responses induced through natural infection and vaccination that interfere in vitro with HCMV infection of FB and EC.
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Affiliation(s)
- Felix Wussow
- Department of Experimental Therapeutics, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA.
| | - Flavia Chiuppesi
- Department of Experimental Therapeutics, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA.
| | - Heidi Contreras
- Department of Experimental Therapeutics, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA.
| | - Don J Diamond
- Department of Experimental Therapeutics, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA.
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Pontejo SM, Murphy PM. Chemokines encoded by herpesviruses. J Leukoc Biol 2017; 102:1199-1217. [PMID: 28848041 DOI: 10.1189/jlb.4ru0417-145rr] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 07/25/2017] [Accepted: 07/26/2017] [Indexed: 12/15/2022] Open
Abstract
Viruses use diverse strategies to elude the immune system, including copying and repurposing host cytokine and cytokine receptor genes. For herpesviruses, the chemokine system of chemotactic cytokines and receptors is a common source of copied genes. Here, we review the current state of knowledge about herpesvirus-encoded chemokines and discuss their possible roles in viral pathogenesis, as well as their clinical potential as novel anti-inflammatory agents or targets for new antiviral strategies.
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Affiliation(s)
- Sergio M Pontejo
- Laboratory of Molecular Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Philip M Murphy
- Laboratory of Molecular Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
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Identification of a novel envelope protein encoded by ORF 136 from Cyprinid herpesvirus 3. Arch Virol 2017; 162:3849-3853. [PMID: 28815395 PMCID: PMC5671517 DOI: 10.1007/s00705-017-3528-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 08/02/2017] [Indexed: 01/01/2023]
Abstract
Cyprinid herpesvirus 3 (CyHV-3) is the pathogenic agent of koi herpesvirus disease (KHVD) afflicting common carp and koi (Cyprinus carpio L.) populations globally. As described previously, proteomic analyses of purified CyHV-3 particles have shown that at least 46 structural proteins are incorporated into CyHV-3 virions; among these ORF136 may encode a putative envelope protein. In this study, Western blotting analysis showed that a specific band with the predicted molecular weight of 17 kDa was detected both in purified virions and envelope components using a rabbit anti-ORF136 polyclonal antibody. Indirect immunofluorescence assay with confocal laser scanning microscopy indicated that the ORF136 protein was distributed in the cytoplasm of CCB cells infected with CyHV-3 and transfected with a pVAX1-ORF136 plasmid. Furthermore, immunogold electron microscopy confirmed that ORF136 protein localized to the CyHV-3 envelope.
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Chiuppesi F, Wussow F, Scharf L, Contreras H, Gao H, Meng Z, Nguyen J, Barry PA, Bjorkman PJ, Diamond DJ. Comparison of homologous and heterologous prime-boost vaccine approaches using Modified Vaccinia Ankara and soluble protein to induce neutralizing antibodies by the human cytomegalovirus pentamer complex in mice. PLoS One 2017; 12:e0183377. [PMID: 28813507 PMCID: PMC5558987 DOI: 10.1371/journal.pone.0183377] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 08/02/2017] [Indexed: 01/15/2023] Open
Abstract
Since neutralizing antibodies (NAb) targeting the human cytomegalovirus (HCMV) pentamer complex (PC) potently block HCMV host cell entry, anti-PC NAb induction is thought to be important for a vaccine formulation to prevent HCMV infection. By developing a vaccine strategy based on soluble PC protein and using a previously generated Modified Vaccinia Ankara vector co-expressing all five PC subunits (MVA-PC), we compared HCMV NAb induction by homologous immunization using prime-boost vaccine regimen employing only PC protein or MVA-PC and heterologous immunization using prime-boost combinations of PC protein and MVA-PC. Utilizing a recently isolated anti-PC NAb, we produced highly pure soluble PC protein that displayed conformational and linear neutralizing epitopes, interfered with HCMV entry, and was recognized by antibodies induced by HCMV during natural infection. Mice vaccinated by different immunization routes with the purified PC protein in combination with a clinically approved adjuvant formulation elicited high-titer and durable HCMV NAb. While MVA-PC and soluble PC protein either alone or in combination elicited robust HCMV NAb, significantly different potencies of these vaccine approaches were observed in dependence on immunization schedule. Using only two immunizations, vaccination with MVA-PC alone or prime-boost combinations of MVA-PC and PC protein was significantly more effective in stimulating HCMV NAb than immunization with PC protein alone. In contrast, with three immunizations, NAb induced by soluble PC protein either alone or combined with two boosts of MVA-PC increased to levels that exceeded NAb titer stimulated by MVA-PC alone. These results provide insights into the potency of soluble protein and MVA to elicit NAb by the HCMV PC via homologous and heterologous prime-boost immunization, which may contribute to develop clinically deployable vaccine strategies to prevent HCMV infection.
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Affiliation(s)
- Flavia Chiuppesi
- Department of Experimental Therapeutics, Beckman Research Institute of the City of Hope, Duarte, CA, United States of America
| | - Felix Wussow
- Department of Experimental Therapeutics, Beckman Research Institute of the City of Hope, Duarte, CA, United States of America
| | - Louise Scharf
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States of America
| | - Heidi Contreras
- Department of Experimental Therapeutics, Beckman Research Institute of the City of Hope, Duarte, CA, United States of America
| | - Han Gao
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States of America
| | - Zhuo Meng
- Department of Experimental Therapeutics, Beckman Research Institute of the City of Hope, Duarte, CA, United States of America
| | - Jenny Nguyen
- Department of Experimental Therapeutics, Beckman Research Institute of the City of Hope, Duarte, CA, United States of America
| | - Peter A. Barry
- Center for Comparative Medicine, California National Primate Research Center, Department of Pathology and Laboratory Medicine, University of California Davis, Davis, CA, United States of America
| | - Pamela J. Bjorkman
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States of America
| | - Don J. Diamond
- Department of Experimental Therapeutics, Beckman Research Institute of the City of Hope, Duarte, CA, United States of America
- * E-mail:
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Chandramouli S, Malito E, Nguyen T, Luisi K, Donnarumma D, Xing Y, Norais N, Yu D, Carfi A. Structural basis for potent antibody-mediated neutralization of human cytomegalovirus. Sci Immunol 2017; 2:2/12/eaan1457. [DOI: 10.1126/sciimmunol.aan1457] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 05/19/2017] [Indexed: 11/02/2022]
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