1
|
The Structures and Functions of VZV Glycoproteins. Curr Top Microbiol Immunol 2021; 438:25-58. [PMID: 34731265 DOI: 10.1007/82_2021_243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The virions of all enveloped viruses, including those of the Herpesviridae, must bind to the cell surface then undergo a process of membrane fusion between the cell plasma membrane and the virus particle envelope. As for all herpesviruses, glycoproteins in the virion envelope are the modus operandi of these events.
Collapse
|
2
|
Sullivan NL, Eberhardt CS, Wieland A, Vora KA, Pulendran B, Ahmed R. Understanding the immunology of the Zostavax shingles vaccine. Curr Opin Immunol 2019; 59:25-30. [PMID: 30970291 DOI: 10.1016/j.coi.2019.02.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 02/21/2019] [Accepted: 02/22/2019] [Indexed: 11/17/2022]
Abstract
Zostavax is a live-attenuated varicella zoster virus (VZV) vaccine recommended for use in adults >50 years of age to prevent shingles. The main risk factor for the development of shingles is age, which correlates with decreasing cell-mediated immunity. These data suggest a predominant role of T cell immunity in controlling VZV latency. However, other components of the immune system may also contribute. In this review, we will discuss how the immune system responds to Zostavax, focusing on recent studies examining innate immunity, transcriptomics, metabolomics, cellular, and humoral immunity.
Collapse
Affiliation(s)
- Nicole L Sullivan
- MRL, Department of Infectious Diseases and Vaccines, Merck & Co., Inc., Kenilworth, New Jersey, USA.
| | - Christiane S Eberhardt
- Emory Vaccine Center and Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA, USA; Center for Vaccinology and Neonatal Immunology, Department of Pediatrics and Pathology-Immunology, University Hospitals of Geneva and Faculty of Medicine, University of Geneva, Switzerland
| | - Andreas Wieland
- Emory Vaccine Center and Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA, USA
| | - Kalpit A Vora
- MRL, Department of Infectious Diseases and Vaccines, Merck & Co., Inc., Kenilworth, New Jersey, USA
| | - Bali Pulendran
- Institute for Immunity, Transplantation and Infection, Department of Pathology, Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305, USA
| | - Rafi Ahmed
- Emory Vaccine Center and Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA, USA
| |
Collapse
|
3
|
Bagdonaite I, Vakhrushev SY, Joshi HJ, Wandall HH. Viral glycoproteomes: technologies for characterization and outlook for vaccine design. FEBS Lett 2018; 592:3898-3920. [PMID: 29961944 DOI: 10.1002/1873-3468.13177] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 06/13/2018] [Accepted: 06/26/2018] [Indexed: 12/27/2022]
Abstract
It has long been known that surface proteins of most enveloped viruses are covered with glycans. It has furthermore been demonstrated that glycosylation is essential for propagation and immune evasion for many viruses. The recent development of high-resolution mass spectrometry techniques has enabled identification not only of the precise structures but also the positions of such post-translational modifications on viruses, revealing substantial differences in extent of glycosylation and glycan maturation for different classes of viruses. In-depth characterization of glycosylation and other post-translational modifications of viral envelope glycoproteins is essential for rational design of vaccines and antivirals. In this Review, we provide an overview of techniques used to address viral glycosylation and summarize information on glycosylation of enveloped viruses representing ongoing public health challenges. Furthermore, we discuss how knowledge on glycosylation can be translated to means to prevent and combat viral infections.
Collapse
Affiliation(s)
- Ieva Bagdonaite
- Department of Cellular and Molecular Medicine, Copenhagen Center for Glycomics, University of Copenhagen, Denmark
| | - Sergey Y Vakhrushev
- Department of Cellular and Molecular Medicine, Copenhagen Center for Glycomics, University of Copenhagen, Denmark
| | - Hiren J Joshi
- Department of Cellular and Molecular Medicine, Copenhagen Center for Glycomics, University of Copenhagen, Denmark
| | - Hans H Wandall
- Department of Cellular and Molecular Medicine, Copenhagen Center for Glycomics, University of Copenhagen, Denmark
| |
Collapse
|
4
|
Bagdonaite I, Wandall HH. Global aspects of viral glycosylation. Glycobiology 2018; 28:443-467. [PMID: 29579213 PMCID: PMC7108637 DOI: 10.1093/glycob/cwy021] [Citation(s) in RCA: 169] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 02/10/2018] [Accepted: 03/21/2018] [Indexed: 12/15/2022] Open
Abstract
Enveloped viruses encompass some of the most common human pathogens causing infections of different severity, ranging from no or very few symptoms to lethal disease as seen with the viral hemorrhagic fevers. All enveloped viruses possess an envelope membrane derived from the host cell, modified with often heavily glycosylated virally encoded glycoproteins important for infectivity, viral particle formation and immune evasion. While N-linked glycosylation of viral envelope proteins is well characterized with respect to location, structure and site occupancy, information on mucin-type O-glycosylation of these proteins is less comprehensive. Studies on viral glycosylation are often limited to analysis of recombinant proteins that in most cases are produced in cell lines with a glycosylation capacity different from the capacity of the host cells. The glycosylation pattern of the produced recombinant glycoproteins might therefore be different from the pattern on native viral proteins. In this review, we provide a historical perspective on analysis of viral glycosylation, and summarize known roles of glycans in the biology of enveloped human viruses. In addition, we describe how to overcome the analytical limitations by using a global approach based on mass spectrometry to identify viral O-glycosylation in virus-infected cell lysates using the complex enveloped virus herpes simplex virus type 1 as a model. We underscore that glycans often pay important contributions to overall protein structure, function and immune recognition, and that glycans represent a crucial determinant for vaccine design. High throughput analysis of glycosylation on relevant glycoprotein formulations, as well as data compilation and sharing is therefore important to identify consensus glycosylation patterns for translational applications.
Collapse
Affiliation(s)
- Ieva Bagdonaite
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3B, Copenhagen N, Denmark
| | - Hans H Wandall
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3B, Copenhagen N, Denmark
| |
Collapse
|
5
|
Breadth and Functionality of Varicella-Zoster Virus Glycoprotein-Specific Antibodies Identified after Zostavax Vaccination in Humans. J Virol 2018; 92:JVI.00269-18. [PMID: 29743372 DOI: 10.1128/jvi.00269-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 04/24/2018] [Indexed: 12/30/2022] Open
Abstract
Herpes zoster (HZ) (shingles) is the clinical manifestation of varicella-zoster virus (VZV) reactivation. HZ typically develops as people age, due to decreased cell-mediated immunity. However, the importance of antibodies for immunity against HZ prevention remains to be understood. The goal of this study was to examine the breadth and functionality of VZV-specific antibodies after vaccination with a live attenuated HZ vaccine (Zostavax). Direct enumeration of VZV-specific antibody-secreting cells (ASCs) via enzyme-linked immunosorbent spot assay (ELISPOT assay) showed that Zostavax can induce both IgG and IgA ASCs 7 days after vaccination but not IgM ASCs. The VZV-specific ASCs range from 33 to 55% of the total IgG ASCs. Twenty-five human VZV-specific monoclonal antibodies (MAbs) were cloned and characterized from single-cell-sorted ASCs of five subjects (>60 years old) who received Zostavax. These MAbs had an average of ∼20 somatic hypermutations per VH gene, similar to those seen after seasonal influenza vaccination. Fifteen of the 25 MAbs were gE specific, whereas the remaining MAbs were gB, gH, or gI specific. The most potent neutralizing antibodies were gH specific and were also able to inhibit cell-to-cell spread of the virus in vitro Most gE-specific MAbs were able to neutralize VZV, but they required the presence of complement and were unable to block cell-to-cell spread. These data indicate that Zostavax induces a memory B cell recall response characterized by anti-gE > anti-gI > anti-gB > anti-gH antibodies. While antibodies to gH could be involved in limiting the spread of VZV upon reactivation, the contribution of anti-gE antibodies toward protective immunity after Zostavax needs further evaluation.IMPORTANCE Varicella-zoster virus (VZV) is the causative agent of chickenpox and shingles. Following infection with VZV, the virus becomes latent and resides in nerve cells. Age-related declines in immunity/immunosuppression can result in reactivation of this latent virus, causing shingles. It has been shown that waning T cell immunity correlates with an increased incidence of VZV reactivation. Interestingly, serum with high levels of VZV-specific antibodies (VariZIG; IV immunoglobulin) has been administered to high-risk populations, e.g., immunocompromised children, newborns, and pregnant women, after exposure to VZV and has shown some protection against chickenpox. However, the relative contribution of antibodies against individual surface glycoproteins toward protection from shingles in elderly/immunocompromised individuals has not been established. Here, we examined the breadth and functionality of VZV-specific antibodies after vaccination with the live attenuated VZV vaccine Zostavax in humans. This study will add to our understanding of the role of antibodies in protection against shingles.
Collapse
|
6
|
Oliver SL, Yang E, Arvin AM. Varicella-Zoster Virus Glycoproteins: Entry, Replication, and Pathogenesis. CURRENT CLINICAL MICROBIOLOGY REPORTS 2016; 3:204-215. [PMID: 28367398 DOI: 10.1007/s40588-016-0044-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Varicella-zoster virus (VZV), an alphaherpesvirus that causes chicken pox (varicella) and shingles (herpes zoster), is a medically important pathogen that causes considerable morbidity and, on occasion, mortality in immunocompromised patients. Herpes zoster can afflict the elderly with a debilitating condition, postherpetic neuralgia, triggering severe, untreatable pain for months or years. The lipid envelope of VZV, similar to all herpesviruses, contains numerous glycoproteins required for replication and pathogenesis. PURPOSE OF REVIEW To summarize the current knowledge about VZV glycoproteins and their roles in cell entry, replication and pathogenesis. RECENT FINDINGS The functions for some VZV glycoproteins are known, such as gB, gH and gL in membrane fusion, cell-cell fusion regulation, and receptor binding properties. However, the molecular mechanisms that trigger or mediate VZV glycoproteins remains poorly understood. SUMMARY VZV glycoproteins are central to successful replication but their modus operandi during replication and pathogenesis remain elusive requiring further mechanistic based studies.
Collapse
Affiliation(s)
- Stefan L Oliver
- Departments of Pediatrics and Microbiology & Immunology, Stanford University School of Medicine, Stanford, California, 94305-5208
| | - Edward Yang
- Departments of Pediatrics and Microbiology & Immunology, Stanford University School of Medicine, Stanford, California, 94305-5208
| | - Ann M Arvin
- Departments of Pediatrics and Microbiology & Immunology, Stanford University School of Medicine, Stanford, California, 94305-5208
| |
Collapse
|
7
|
Role for the αV Integrin Subunit in Varicella-Zoster Virus-Mediated Fusion and Infection. J Virol 2016; 90:7567-78. [PMID: 27279620 DOI: 10.1128/jvi.00792-16] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 06/03/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Varicella-zoster virus (VZV) is an alphaherpesvirus that causes varicella and herpes zoster. Membrane fusion is essential for VZV entry and the distinctive syncytium formation in VZV-infected skin and neuronal tissue. Herpesvirus fusion is mediated by a complex of glycoproteins gB and gH-gL, which are necessary and sufficient for VZV to induce membrane fusion. However, the cellular requirements of fusion are poorly understood. Integrins have been implicated to facilitate entry of several human herpesviruses, but their role in VZV entry has not yet been explored. To determine the involvement of integrins in VZV fusion, a quantitative cell-cell fusion assay was developed using a VZV-permissive melanoma cell line. The cells constitutively expressed a reporter protein and short hairpin RNAs (shRNAs) to knock down the expression of integrin subunits shown to be expressed in these cells by RNA sequencing. The αV integrin subunit was identified as mediating VZV gB/gH-gL fusion, as its knockdown by shRNAs reduced fusion levels to 60% of that of control cells. A comparable reduction in fusion levels was observed when an anti-αV antibody specific to its extracellular domain was tested in the fusion assay, confirming that the domain was important for VZV fusion. In addition, reduced spread was observed in αV knockdown cells infected with the VZV pOka strain relative to that of the control cells. This was demonstrated by reductions in plaque size, replication kinetics, and virion entry in the αV subunit knockdown cells. Thus, the αV integrin subunit is important for VZV gB/gH-gL fusion and infection. IMPORTANCE Varicella-zoster virus (VZV) is a highly infectious pathogen that causes chickenpox and shingles. A common complication of shingles is the excruciating condition called postherpetic neuralgia, which has proven difficult to treat. While a vaccine is now available, it is not recommended for immunocompromised individuals and its efficacy decreases with the recipient's age. These limitations highlight the need for new therapies. This study examines the role of integrins in membrane fusion mediated by VZV glycoproteins gB and gH-gL, a required process for VZV infection. This knowledge will further the understanding of VZV entry and provide insight into the development of better therapies.
Collapse
|
8
|
Serological Evaluation of Immunity to the Varicella-Zoster Virus Based on a Novel Competitive Enzyme-Linked Immunosorbent Assay. Sci Rep 2016; 6:20577. [PMID: 26853741 PMCID: PMC4744930 DOI: 10.1038/srep20577] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 01/06/2016] [Indexed: 12/18/2022] Open
Abstract
Varicella-zoster virus (VZV) is a highly contagious agent of varicella and herpes zoster. Varicella can be lethal to immunocompromised patients, babies, HIV patients and other adults with impaired immunity. Serological evaluation of immunity to VZV will help determine which individuals are susceptible and evaluate vaccine effectiveness. A collection of 110 monoclonal antibodies (mAbs) were obtained by immunization of mice with membrane proteins or cell-free virus. The mAbs were well characterized, and a competitive sandwich ELISA (capture mAb: 8H6; labelling mAb: 1B11) was established to determine neutralizing antibodies in human serum with reference to the FAMA test. A total of 920 human sera were evaluated. The competitive sandwich ELISA showed a sensitivity of 95.6%, specificity of 99.77% and coincidence of 97.61% compared with the fluorescent-antibody-to-membrane-antigen (FAMA) test. The capture mAb 8H6 was characterized as a specific mAb for VZV ORF9, a membrane-associated tegument protein that interacts with glycoprotein E (gE), glycoprotein B (gB) and glycoprotein C (gC). The labelling mAb 1B11 was characterized as a complement-dependent neutralizing mAb specific for the immune-dominant epitope located on gE, not on other VZV glycoproteins. The established competitive sandwich ELISA could be used as a rapid and high-throughput method for evaluating immunity to VZV.
Collapse
|
9
|
A site of varicella-zoster virus vulnerability identified by structural studies of neutralizing antibodies bound to the glycoprotein complex gHgL. Proc Natl Acad Sci U S A 2015; 112:6056-61. [PMID: 25918416 PMCID: PMC4434712 DOI: 10.1073/pnas.1501176112] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Mapping neutralizing epitopes on viral entry glycoproteins allows the identification of potentially important functional regions. The structure of varicella-zoster virus (VZV) gHgL bound to two antibodies isolated from immune donors reveals a common binding site. Functional experiments demonstrate that the two antibodies neutralize VZV infection and inhibit glycoprotein gB/glycoprotein complex gHgL-mediated membrane fusion. Immunization experiments in mice demonstrate that VZV gHgL elicits potently neutralizing antibodies and confirm the key role of this antigenic site in antibody-mediated virus neutralization. This manuscript sheds light on the molecular mechanism of herpesvirus cell entry and will guide the design of subunit-based vaccines against VZV. Varicella-zoster virus (VZV), of the family Alphaherpesvirinae, causes varicella in children and young adults, potentially leading to herpes zoster later in life on reactivation from latency. The conserved herpesvirus glycoprotein gB and the heterodimer gHgL mediate virion envelope fusion with cell membranes during virus entry. Naturally occurring neutralizing antibodies against herpesviruses target these entry proteins. To determine the molecular basis for VZV neutralization, crystal structures of gHgL were determined in complex with fragments of antigen binding (Fabs) from two human monoclonal antibodies, IgG-94 and IgG-RC, isolated from seropositive subjects. These structures reveal that the antibodies target the same site, composed of residues from both gH and gL, distinct from two other neutralizing epitopes identified by negative-stain electron microscopy and mutational analysis. Inhibition of gB/gHgL-mediated membrane fusion and structural comparisons with herpesvirus homologs suggest that the IgG-RC/94 epitope is in proximity to the site on VZV gHgL that activates gB. Immunization studies proved that the anti-gHgL IgG-RC/94 epitope is a critical target for antibodies that neutralize VZV. Thus, the gHgL/Fab structures delineate a site of herpesvirus vulnerability targeted by natural immunity.
Collapse
|
10
|
Lee ST, Bracci P, Zhou M, Rice T, Wiencke J, Wrensch M, Wiemels J. Interaction of allergy history and antibodies to specific varicella-zoster virus proteins on glioma risk. Int J Cancer 2013; 134:2199-210. [PMID: 24127236 DOI: 10.1002/ijc.28535] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 09/05/2013] [Accepted: 09/30/2013] [Indexed: 12/26/2022]
Abstract
Glioma is the most common cancer of the central nervous system but with few confirmed risk factors. It has been inversely associated with chicken pox, shingles and seroreactivity to varicella virus (VZV), as well as to allergies and allergy-associated IgE. The role of antibody reactivity against individual VZV antigens has not been assessed. Ten VZV-related proteins, selected for high immunogenicity or known function, were synthesized and used as targets for antibody measurements in the sera of 143 glioma cases and 131 healthy controls selected from the San Francisco Bay Area Adult Glioma Study. Glioma cases exhibited significantly reduced seroreactivity compared to controls for six antigens, including proteins IE63 [odds ratio (OR) = 0.26, 95% confidence interval (CI): 0.12-0.58, comparing lowest quartile to highest) and the VZV-unique protein ORF2p (OR = 0.44, 95% CI: 0.21-0.96, lowest quartile to highest). When stratifying the study population into those with low and high self-reported allergy history, VZV protein seroreactivity was only associated inversely with glioma among individuals self-reporting more than two allergies. The data provide insight into both allergy and VZV effects on glioma: strong anti-VZV reactions in highly allergic individuals are associated with reduced occurrence of glioma. This result suggests a role for specificity in the anti-VZV immunity in brain tumor suppression for both individual VZV antigens and in the fine-tuning of the immune response by allergy. Anti-VZV reactions may also be a biomarker of effective CNS immunosurveillance owing to the tropism of the virus.
Collapse
Affiliation(s)
- Seung-Tae Lee
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA; Department of Laboratory Medicine & Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | | | | | | | | | | | | |
Collapse
|
11
|
Ceroni A, Sibani S, Baiker A, Pothineni VR, Bailer SM, LaBaer J, Haas J, Campbell CJ. Systematic analysis of the IgG antibody immune response against varicella zoster virus (VZV) using a self-assembled protein microarray. MOLECULAR BIOSYSTEMS 2010; 6:1604-10. [PMID: 20514382 DOI: 10.1039/c003798b] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Varicella zoster virus (VZV) is a human herpesvirus encoding at least 69 distinct viral proteins which causes chickenpox after primary infection and shingles during reactivation and which is particularly important in pregnancy and immunocompromised patients. Current serodiagnostic tests are either based on whole cell lysates or glycoprotein preparations. In order to investigate the humoral immune response to VZV infection or vaccination in more detail, and to improve the currently available diagnostic assays, we developed a nucleic acid programmable protein array (NAPPA) containing all 69 VZV proteins and performed a detailed analysis of 68 sera from individuals with either no, a previous or an acute VZV infection. In addition to the known reactive glycoprotein antigens (ORF 5, ORF 14, ORF 31, ORF 37, ORF 68), we discovered IgG antibodies against a variety of other membrane (ORF 2, ORF 24), capsid (ORF 20, ORF 23, ORF 43) and tegument (ORF 53, ORF 9, ORF 11) proteins, as well as other proteins involved in virus replication and assembly (ORF 25, ORF 26, ORF 28) and the transactivator proteins ORF 12, ORF 62 and ORF 63. All of these antigens were only reactive in a subset of VZV-positive individuals. A subset of the newly identified VZV antigens was validated by western blot analysis. Using these seroreactive new VZV antigens, more sensitive assays and tests distinguishing between different clinical entities may be developed.
Collapse
Affiliation(s)
- Alessandro Ceroni
- Division of Pathway Medicine, University of Edinburgh, 49 Little France Crescent, Edinburgh, UK EH16 4SB
| | | | | | | | | | | | | | | |
Collapse
|
12
|
Anti-glycoprotein H antibody impairs the pathogenicity of varicella-zoster virus in skin xenografts in the SCID mouse model. J Virol 2010; 84:141-52. [PMID: 19828615 DOI: 10.1128/jvi.01338-09] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Varicella-zoster virus (VZV) infection is usually mild in healthy individuals but can cause severe disease in immunocompromised patients. Prophylaxis with varicella-zoster immunoglobulin can reduce the severity of VZV if given shortly after exposure. Glycoprotein H (gH) is a highly conserved herpesvirus protein with functions in virus entry and cell-cell spread and is a target of neutralizing antibodies. The anti-gH monoclonal antibody (MAb) 206 neutralizes VZV in vitro. To determine the requirement for gH in VZV pathogenesis in vivo, MAb 206 was administered to SCID mice with human skin xenografts inoculated with VZV. Anti-gH antibody given at 6 h postinfection significantly reduced the frequency of skin xenograft infection by 42%. Virus titers, genome copies, and lesion size were decreased in xenografts that became infected. In contrast, administering anti-gH antibody at 4 days postinfection suppressed VZV replication but did not reduce the frequency of infection. The neutralizing anti-gH MAb 206 blocked virus entry, cell fusion, or both in skin in vivo. In vitro, MAb 206 bound to plasma membranes and to surface virus particles. Antibody was internalized into vacuoles within infected cells, associated with intracellular virus particles, and colocalized with markers for early endosomes and multivesicular bodies but not the trans-Golgi network. MAb 206 blocked spread, altered intracellular trafficking of gH, and bound to surface VZV particles, which might facilitate their uptake and targeting for degradation. As a consequence, antibody interference with gH function would likely prevent or significantly reduce VZV replication in skin during primary or recurrent infection.
Collapse
|
13
|
Characterization of neutralizing epitopes of varicella-zoster virus glycoprotein H. J Virol 2008; 83:2020-4. [PMID: 19073736 DOI: 10.1128/jvi.02097-08] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Varicella-zoster virus (VZV) glycoprotein H (gH) is the major neutralization target of VZV, and its neutralizing epitope is conformational. Ten neutralizing human monoclonal antibodies to gH were used to map the epitopes by immunohistochemical analysis and were categorized into seven epitope groups. The combinational neutralization efficacy of two epitope groups was not synergistic. Each epitope was partially or completely resistant to concanavalin A blocking of the glycomoiety of gH, and their antibodies inhibited the cell-to-cell spread of infection. The neutralization epitope comprised at least seven independent protein portions of gH that served as the target to inhibit cell-to-cell spread.
Collapse
|
14
|
Suzuki K, Akahori Y, Asano Y, Kurosawa Y, Shiraki K. Isolation of therapeutic human monoclonal antibodies for varicella-zoster virus and the effect of light chains on the neutralizing activity. J Med Virol 2007; 79:852-62. [PMID: 17457901 DOI: 10.1002/jmv.20838] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Therapeutic antibodies against varicella-zoster virus (VZV) were isolated from a combinatorial library of human antibodies using a phage-display system. Purified gH:gL was used to screen the library, and approximately 300 clones were isolated. Eight kinds of Fab-cp3-fused molecules (clones 10, 24, 36, 60, 94, 120, 192, and 431) neutralized viral infectivity. After conversion of Fab-cp3 antibodies to the Fab-protein A form, the concentrations of antibodies showing 50% inhibition of plaque formation ranged from 0.12 to 400 nM. Clones 10, 24, 94, 120 and 431 neutralized wild strains without showing strain specificity and were further converted to human IgG(1). Two clones (24 and 94) were confirmed to react with gH:gL and VZV-infected cells. IgG of clone 94 prevented spreading of infected cells. Thus these antibodies exhibited the typical phenotype of anti-gH antibody. Next the contribution of light (L) chains to neutralizing activity was analyzed by comparing the effect of L chain of clones 10, 120, and 192 with the identical heavy chain on their neutralizing activity. The L chain in the Fab form of clone 94 was replaced by L chains of clones 10, 24, 36, and 60 and the neutralizing activity of these replaced antibodies was weaker than that of the prototype clone 94. When the kappa-L chain of clone 94 was replaced by the lambda-L chain of clone 24, this antibody possessed neutralizing activity despite the kappa-lambda class change. Thus, human antibody library against VZV-gH has been established and characterized the role of the L chain in VZV-neutralizing activity to engineering further an antibody with stronger neutralizing activity.
Collapse
|
15
|
Maresova L, Pasieka TJ, Homan E, Gerday E, Grose C. Incorporation of three endocytosed varicella-zoster virus glycoproteins, gE, gH, and gB, into the virion envelope. J Virol 2005; 79:997-1007. [PMID: 15613328 PMCID: PMC538533 DOI: 10.1128/jvi.79.2.997-1007.2005] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The cytoplasmic tails of all three major varicella-zoster virus (VZV) glycoproteins, gE, gH, and gB, harbor functional tyrosine-based endocytosis motifs that mediate internalization. The aim of the present study was to examine whether endocytosis from the plasma membrane is a cellular route by which VZV glycoproteins are delivered to the final envelopment compartment. In this study, we demonstrated that internalization of the glycoproteins occurred in the first 24 h postinfection but was reduced later in infection. Using surface biotinylation of VZV-infected cells followed by a glutathione cleavage assay, we showed that endocytosis was independent of antibody binding to gE, gH, and gB. Subsequently, with this assay, we demonstrated that biotinylated gE, gH, and gB retrieved from the cell surface were incorporated into nascent virus particles isolated after density gradient sedimentation. To confirm and extend this finding, we repeated the above sedimentation step and specifically detected envelopes decorated with Streptavidin-conjugated gold beads on a majority of complete virions through examination by transmission electron microscopy. In addition, a gE-gI complex and a gE-gH complex were found on the virions. Therefore, the above studies established that VZV subsumed a postendocytosis trafficking pathway as one mechanism by which to deliver viral glycoproteins to the site of virion assembly in the cytoplasm. Furthermore, since a recombinant VZV genome lacking only endocytosis-competent gE cannot replicate, these results supported the conclusion that the endocytosis-envelopment pathway is an essential component of the VZV life cycle.
Collapse
Affiliation(s)
- Lucie Maresova
- University of Iowa Hospital/2501 JCP, 200 Hawkins Dr., Iowa City, IA 52242, USA
| | | | | | | | | |
Collapse
|
16
|
Kausmally L, Waalen K, Løbersli I, Hvattum E, Berntsen G, Michaelsen TE, Brekke OH. Neutralizing human antibodies to varicella-zoster virus (VZV) derived from a VZV patient recombinant antibody library. J Gen Virol 2004; 85:3493-3500. [PMID: 15557222 DOI: 10.1099/vir.0.80406-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Varicella-zoster virus (VZV), the causative agent of chickenpox and herpes zoster, can be life-threatening in prematurely born children and in children with immune defects or who are under immunosuppressive treatment. Therefore agents for passive immunization, such as VZV-specific immunoglobulin preparations (VZIG) derived from convalescent plasma, are crucial in the prophylaxis of VZV infection. This study describes the isolation of human VZV-neutralizing recombinant antibodies. A human single-chain variable fragment (scFv) phage display library was generated from RNA extracted from peripheral blood lymphocytes of a convalescent varicella patient. Specific phage antibodies were selected against VZV-infected human fibroblasts, and eight unique clones were further expressed as soluble scFv in Escherichia coli. They all showed binding characteristics to varicella antigens with affinities in the K(D) range 0.1-0.2 muM. Two of the scFv antibodies, VZV4 and VZV5, showed dose-dependent in vitro neutralization of VZV. VZV39 also showed a neutralizing effect as scFv, an effect that was increased 4000-fold by conversion into IgG and was further increased by the addition of complement. This is possibly the first time that monovalent scFv antibodies have been shown to neutralize VZV in vitro. This finding will have an impact on the production of new prophylactic antibodies, as such antibody fragments can be cost-effectively produced in E. coli. The antibodies isolated bind both complement-dependent and -independent epitopes for neutralization, thus they may prove useful tools for the study of VZV virulence mechanisms.
Collapse
Affiliation(s)
- L Kausmally
- Agricultural University of Norway, Institute for Biotechnology, Ås, Norway
| | - K Waalen
- The Norwegian Institute of Public Health, Division for Infectious Disease Control, Oslo, Norway
| | - I Løbersli
- Affitech AS, Oslo Research Park, Gaustadalleen 21, 0349 Oslo, Norway
| | - E Hvattum
- Affitech AS, Oslo Research Park, Gaustadalleen 21, 0349 Oslo, Norway
| | - G Berntsen
- Affitech AS, Oslo Research Park, Gaustadalleen 21, 0349 Oslo, Norway
| | - T E Michaelsen
- The Norwegian Institute of Public Health, Division for Infectious Disease Control, Oslo, Norway
| | - O H Brekke
- Affitech AS, Oslo Research Park, Gaustadalleen 21, 0349 Oslo, Norway
| |
Collapse
|
17
|
Akkapaiboon P, Mori Y, Sadaoka T, Yonemoto S, Yamanishi K. Intracellular processing of human herpesvirus 6 glycoproteins Q1 and Q2 into tetrameric complexes expressed on the viral envelope. J Virol 2004; 78:7969-83. [PMID: 15254169 PMCID: PMC446105 DOI: 10.1128/jvi.78.15.7969-7983.2004] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human herpesvirus 6 (HHV-6) glycoproteins H and L (gH and gL, respectively) and the 80-kDa form of glycoprotein Q (gQ-80K) form a heterotrimeric complex that is found on the viral envelope and that is a viral ligand for human CD46. Besides gQ-80K, the gQ gene encodes an additional product whose mature molecular mass is 37 kDa (gQ-37K) and which is derived from a different transcript. Therefore, we designated gQ-80K as gQ1 and gQ-37K as gQ2. We show here that gQ2 also interacts with the gH-gL-gQ1 complex in HHV-6-infected cells and in virions. To examine how these components interact in HHV-6-infected cells, we performed pulse-chase studies. The results demonstrated that gQ2-34K, which is endo-beta-N-acetylglucosaminidase H sensitive and which is the precursor form of gQ2-37K, associates with gQ1-74K, which is the precursor form of gQ1-80K, within 30 min of the pulse period. After a 1-h chase, these precursor forms had associated with the gH-gL dimer. Interestingly, an anti-gH monoclonal antibody coimmunoprecipitated mainly gQ1-80K and gQ2-37K, with little gQ1-74K or gQ2-34K. These results indicate that although gQ2-34K and gQ1-74K interact in the endoplasmic reticulum, the gH-gL-gQ1-80K-gQ2-37K heterotetrameric complex arises in the post-endoplasmic reticulum compartment. The mature complex is subsequently incorporated into viral particles.
Collapse
Affiliation(s)
- Pilailuk Akkapaiboon
- Department of Microbiology, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan
| | | | | | | | | |
Collapse
|
18
|
Pasieka TJ, Maresova L, Shiraki K, Grose C. Regulation of varicella-zoster virus-induced cell-to-cell fusion by the endocytosis-competent glycoproteins gH and gE. J Virol 2004; 78:2884-96. [PMID: 14990707 PMCID: PMC353742 DOI: 10.1128/jvi.78.6.2884-2896.2004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The gH glycoprotein of varicella-zoster virus (VZV) is a major fusogen. The realigned short cytoplasmic tail of gH (18 amino acids) harbors a functional endocytosis motif (YNKI) that mediates internalization in both VZV-infected and transfected cells (T. J. Pasieka, L. Maresova, and C. Grose, J. Virol. 77: 4194-4202, 2003). During subsequent confocal microscopy studies of endocytosis-deficient gH mutants, we observed that cells transfected with the gH tail mutants exhibited marked fusion. Therefore, we postulated that VZV gH endocytosis served to regulate cell-to-cell fusion. Subsequent analyses of gH+gL transfection fusion assays by the Kolmogorov-Smirnov statistical test demonstrated that expression of the endocytosis-deficient gH mutants resulted in a statistically significant enhancement of cell-to-cell fusion (P < 0.0001) compared to wild-type gH. On the other hand, coexpression of VZV gE, another endocytosis-competent VZV glycoprotein, was able to temper the fusogenicity of the gH endocytosis mutants by facilitating internalization of the mutant gH protein from the cell surface. When the latter results were similarly analyzed, there was no longer any enhanced fusion by the endocytosis-deficient gH mutant protein. In summary, these studies support a role for gH endocytosis in regulating the cell surface expression of gH and thereby regulating gH-mediated fusion. The data also confirm and extend prior observations of a gE-gH interaction during viral glycoprotein trafficking in a VZV transfection system.
Collapse
Affiliation(s)
- Tracy Jo Pasieka
- Department of Pediatrics, University of Iowa College of Medicine, Iowa City, Iowa, USA
| | | | | | | |
Collapse
|
19
|
Pasieka TJ, Maresova L, Grose C. A functional YNKI motif in the short cytoplasmic tail of varicella-zoster virus glycoprotein gH mediates clathrin-dependent and antibody-independent endocytosis. J Virol 2003; 77:4191-204. [PMID: 12634377 PMCID: PMC150655 DOI: 10.1128/jvi.77.7.4191-4204.2003] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The trafficking of varicella-zoster virus (VZV) gH was investigated under both infection and transfection conditions. In initial endocytosis assays performed in infected cells, the three glycoproteins gE, gI, and gB served as positive controls for internalization from the plasma membrane. Subsequently, we discovered that gH in VZV-infected cells was also internalized and followed a similar trafficking pattern. This observation was unexpected because all herpesvirus gH homologues have short endodomains not known to contain trafficking motifs. Further investigation demonstrated that VZV gH, when expressed alone with its chaperone gL, was capable of endocytosis in a clathrin-dependent manner, independent of gE, gI, or gB. Upon inspection of the short gH cytoplasmic tail, we discovered a putative tyrosine-based endocytosis motif (YNKI). When the tyrosine was replaced with an alanine, endocytosis of gH was blocked. Utilizing an endocytosis assay dependent on biotin labeling, we further documented that endocytosis of VZV gH was antibody independent. In control experiments, we showed that gE, gI, and gB also internalized in an antibody-independent manner. Alignment analysis of the VZV gH cytoplasmic tail to other herpesvirus gH homologues revealed two important findings: (i) herpes simplex virus type 1 and 2 homologues lacked an endocytosis motif, while all other alphaherpesvirus gH homologues contained a potential motif, and (ii) the VZV gH and simian varicella virus gH cytoplasmic tails were likely longer in length (18 amino acids) than predicted in the original sequence analyses (12 and 16 amino acids, respectively). The longer tails provided the proper context for a functional endocytosis motif.
Collapse
|
20
|
Maresova L, Pasieka TJ, Grose C. Varicella-zoster Virus gB and gE coexpression, but not gB or gE alone, leads to abundant fusion and syncytium formation equivalent to those from gH and gL coexpression. J Virol 2001; 75:9483-92. [PMID: 11533210 PMCID: PMC114515 DOI: 10.1128/jvi.75.19.9483-9492.2001] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Varicella-zoster virus (VZV) is distinguished from herpes simplex virus type 1 (HSV-1) by the fact that cell-to-cell fusion and syncytium formation require only gH and gL within a transient-expression system. In the HSV system, four glycoproteins, namely, gH, gL, gB, and gD, are required to induce a similar fusogenic event. VZV lacks a gD homologous protein. In this report, the role of VZV gB as a fusogen was investigated and compared to the gH-gL complex. First of all, the VZV gH-gL experiment was repeated under a different set of conditions; namely, gH and gL were cloned into the same vaccinia virus (VV) genome. Surprisingly, the new expression system demonstrated that a recombinant VV-gH+gL construct was even more fusogenic than seen in the prior experiment with two individual expression plasmids containing gH and gL (K. M. Duus and C. Grose, J. Virol. 70:8961-8971, 1996). Recombinant VV expressing VZV gB by itself, however, effected the formation of only small syncytia. When VZV gE and gB genes were cloned into one recombinant VV genome and another fusion assay was performed, extensive syncytium formation was observed. The degree of fusion with VZV gE-gB coexpression was comparable to that observed with VZV gH-gL: in both cases, >80% of the cells in a monolayer were fused. Thus, these studies established that VZV gE-gB coexpression greatly enhanced the fusogenic properties of gB. Control experiments documented that the fusion assay required a balance between the fusogenic potential of the VZV glycoproteins and the fusion-inhibitory effect of the VV infection itself.
Collapse
Affiliation(s)
- L Maresova
- Department of Microbiology, University of Iowa, Iowa City, Iowa, USA
| | | | | |
Collapse
|
21
|
Drew PD, Moss MT, Pasieka TJ, Grose C, Harris WJ, Porter AJR. Multimeric humanized varicella-zoster virus antibody fragments to gH neutralize virus while monomeric fragments do not. J Gen Virol 2001; 82:1959-1963. [PMID: 11458003 DOI: 10.1099/0022-1317-82-8-1959] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Murine monoclonal antibody 206 (MAb mu206) binds to gH, the varicella-zoster virus (VZV) fusogen, neutralizing the virus in vitro in the absence of complement and inhibiting cell-to-cell spread and egress of VZV in cultured cells. We have humanized this antibody to generate MAb hu206 by complementarity determining region grafting. MAb hu206 retained binding and in vitro neutralizing activity, as well as cross-reactivity with ten different VZV strains. Single-chain antibody fragments (scAb) derived from MAb hu206 were produced in Escherichia coli. These scAb retained the binding properties of the whole antibody. However, monomeric scAb exhibited markedly reduced neutralizing activity compared to the bivalent parental MAb hu206. Shortening the peptide linker joining the V(H) to the V(kappa) domain from 14 to 5 or even 0 residues encouraged multimerization and increased neutralizing efficacy. The fact that Fab fragments enzymatically generated from whole MAb hu206 lost their neutralizing potency lent support to the proposal that valency is important for VZV neutralization at this epitope.
Collapse
Affiliation(s)
- P D Drew
- University of Aberdeen, Department of Molecular and Cell Biology, Institute of Medical Sciences, Foresterhill, Aberdeen AB25 2ZD, UK1
| | - M T Moss
- Scotgen Biopharmaceuticals Inc., Kettock Lodge, Aberdeen Science and Technology Park, Aberdeen AB22 8GU, UK3
| | - T J Pasieka
- Department of Microbiology, University of Iowa College of Medicine, Iowa City, IA 52242, USA2
| | - C Grose
- Department of Microbiology, University of Iowa College of Medicine, Iowa City, IA 52242, USA2
| | - W J Harris
- Scotgen Biopharmaceuticals Inc., Kettock Lodge, Aberdeen Science and Technology Park, Aberdeen AB22 8GU, UK3
- University of Aberdeen, Department of Molecular and Cell Biology, Institute of Medical Sciences, Foresterhill, Aberdeen AB25 2ZD, UK1
| | - A J R Porter
- University of Aberdeen, Department of Molecular and Cell Biology, Institute of Medical Sciences, Foresterhill, Aberdeen AB25 2ZD, UK1
| |
Collapse
|
22
|
Kutinová L, Hainz P, Ludvíková V, Maresová L, Nĕmecková S. Immune response to vaccinia virus recombinants expressing glycoproteins gE, gB, gH, and gL of Varicella-zoster virus. Virology 2001; 280:211-20. [PMID: 11162835 DOI: 10.1006/viro.2000.0754] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Immunogenicity of Varicella-zoster virus glycoproteins gE, gB, gH, and gL expressed by recombinant vaccinia viruses (VV) separately or simultaneously was determined in mice and guinea pigs by ELISA, Western blotting, radioimmunoprecipitation, plaque reduction assay, and skin test. Single VV-gE and VV-gB recombinants and double VV-gH/gL recombinant elicited specific antibodies with VZV neutralizing activity in mice. Co-expression of gE and gB by one recombinant VV resulted in an increased antibody response in comparison with immunization with single recombinants or their mixtures. Unlike anti-gB and anti-gH/gL antibodies, the gE-specific antibodies had no virus neutralizing activity in absence of complement, and when used alone, they even caused considerable increase of VZV infectious units. Moreover, immune sera containing anti-gE antibodies antagonized complement independent virus-neutralizing activity of anti-gB- and anti-gH/gL-positive sera. The ability to induce delayed hypersensitivity reaction to VZV antigens was observed after immunization of guinea pigs with gE- and/or gB-expressing VVs.
Collapse
Affiliation(s)
- L Kutinová
- Department of Experimental Virology, Institute of Hematology and Blood Transfusion, U nemocnice 1, CZ-128 20 Prague 2, Czech Republic
| | | | | | | | | |
Collapse
|
23
|
Yokoyama T, Ayabe S, Miyagi H, Sugano T, Otsu A, Sato H, Kageyama S, Fujii T, Shiraki K. Varicella-zoster virus gH:gL contains a structure reactive with the anti-human gamma chain of IgG near the glycosylation site. J Gen Virol 2001; 82:331-334. [PMID: 11161270 DOI: 10.1099/0022-1317-82-2-331] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Varicella-zoster virus (VZV) glycoproteins were purified from infected cells using monoclonal antibodies and gH:gL was found to react with antibodies to the gamma chain of human IgG (h-IgG), whereas gE:gI and gB did not. When gH:gL was captured by concanavalin A, it lost reactivity with the anti-h-IgG gamma chain (anti-h-gamma-IgG). gH:gL reacted with anti-h-gamma-IgG in an ELISA assay and gave a K:(d) value of 2.16x10(-7) M in a BIAcore assay. The K:(d) value of the human monoclonal antibody to gH (TI-57) used for the purification of gH:gL was 4.45x10(-10) M. Virus pretreated with anti-h-IgG was five times more resistant to neutralization with TI-57. Although the nature of the binding was not clear, gH:gL bound to anti-h-gamma-IgG. If this interaction results from immunological similarity between gH:gL and h-IgG, it may cause immune evasion in the pathogenesis of VZV infection.
Collapse
Affiliation(s)
- Tomonori Yokoyama
- Teijin Institute for Biomedical Research, Asahigaoka 4-3-2, Hino, Tokyo 191, Japan2
- Department of Virology, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama 930-01, Japan1
| | - Satoko Ayabe
- Teijin Institute for Biomedical Research, Asahigaoka 4-3-2, Hino, Tokyo 191, Japan2
| | - Huminori Miyagi
- Teijin Institute for Biomedical Research, Asahigaoka 4-3-2, Hino, Tokyo 191, Japan2
| | - Toru Sugano
- Teijin Institute for Biomedical Research, Asahigaoka 4-3-2, Hino, Tokyo 191, Japan2
| | - Akira Otsu
- Teijin Institute for Biomedical Research, Asahigaoka 4-3-2, Hino, Tokyo 191, Japan2
| | - Hitoshi Sato
- Department of Virology, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama 930-01, Japan1
| | - Seiji Kageyama
- Department of Virology, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama 930-01, Japan1
| | - Takao Fujii
- Teijin Institute for Biomedical Research, Asahigaoka 4-3-2, Hino, Tokyo 191, Japan2
| | - Kimiyasu Shiraki
- Department of Virology, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama 930-01, Japan1
| |
Collapse
|
24
|
Maresová L, Kutinová L, Ludvíková V, Zák R, Mares M, Nemecková S. Characterization of interaction of gH and gL glycoproteins of varicella-zoster virus: their processing and trafficking. J Gen Virol 2000; 81:1545-52. [PMID: 10811938 DOI: 10.1099/0022-1317-81-6-1545] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Varicella-zoster virus (VZV) glycoproteins gH and gL were examined in a recombinant vaccinia virus system. Single expression of glycoprotein gL produced two molecular forms: an 18 kDa form and a 19 kDa form differing in size by one endoglycosidase H-sensitive N-linked oligosaccharide. Coexpression of gL and gH resulted in binding of the 18 kDa gL form with the mature form of gH, while the 19 kDa gL form remained uncomplexed. The glycosylation processing of gL was not dependent on gH; however, gL was required for the conversion of precursor gH (97 kDa) to mature gH (118 kDa). Subsequent analyses indicated that gL (18 kDa) was a more completely processed gL (19 kDa). Screening of the culture media revealed that gH and gL were secreted, but only if coexpressed and complexed together. The secreted form of gL was 18 kDa while that of gH was 114 kDa. The fact that secreted gH was smaller than intracytoplasmic gH suggested a proteolytic processing event prior to secretion. The 19 kDa form of gL was never secreted. These findings support a VZV gL recycling pathway between the endoplasmic reticulum and the cis-Golgi apparatus.
Collapse
Affiliation(s)
- L Maresová
- Institute of Haematology and Blood Transfusion, Dept of Experimental Virology, Prague 128 20, Czech Republic.
| | | | | | | | | | | |
Collapse
|
25
|
Klupp BG, Fuchs W, Weiland E, Mettenleiter TC. Pseudorabies virus glycoprotein L is necessary for virus infectivity but dispensable for virion localization of glycoprotein H. J Virol 1997; 71:7687-95. [PMID: 9311852 PMCID: PMC192119 DOI: 10.1128/jvi.71.10.7687-7695.1997] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Herpesviruses contain a number of envelope glycoproteins which play important roles in the interaction between virions and target cells. Although several glycoproteins are not present in all herpesviruses, others, including glycoproteins H and L (gH and gL), are conserved throughout the Herpesviridae. To elucidate common properties and differences in herpesvirus glycoprotein function, corresponding virus mutants must be constructed and analyzed in different herpesvirus backgrounds. Analysis of gH- mutants of herpes simplex virus type 1 (HSV-1) and pseudorabies virus (PrV) showed that in both viruses gH is essential for penetration and cell-to-cell spread and that its presence is required for virion localization of gL. Since gH homologs are found complexed with gL, it was of interest to assess the phenotype of gL- mutant viruses. By using this approach, HSV-1 gL has been shown to be required for entry and for virion localization of gH (C. Roop, L. Hutchinson, and D. Johnson, J. Virol. 67:2285-2297, 1993). To examine whether a similar phenotype is associated with lack of gL in another alphaherpesvirus, PrV, we constructed two independent gL- PrV mutants by insertion and deletion-insertion mutagenesis. The salient findings are as follows: (i) PrV gL is required for penetration of virions and cell-to-cell spread; (ii) unlike HSV-1, PrV gH is incorporated into the virion in the absence of gL; (iii) virion localization of gH in the absence of gL is not sufficient for infectivity; (iv) in the absence of gL, N-glycans on PrV gH are processed to a greater extent than in the presence of gL, indicating masking of N-glycans by association with gL; and (v) an anti-gL polyclonal antiserum is able to neutralize virion infectivity but did not inhibit cell-to-cell spread. Thus, whereas PrV gL is essential for virus replication, as is HSV-1 gL, gL- PrV mutants exhibit properties strikingly different from those of HSV-1. In conclusion, our data show an important functional role for PrV gL in the viral entry process, which is not explained by a chaperone-type mechanism in gH maturation and processing.
Collapse
Affiliation(s)
- B G Klupp
- Institute of Molecular and Cellular Virology, Friedrich-Loeffler-Institutes, Federal Research Centre for Virus Diseases of Animals, Insel Riems, Germany
| | | | | | | |
Collapse
|
26
|
Duus KM, Grose C. Multiple regulatory effects of varicella-zoster virus (VZV) gL on trafficking patterns and fusogenic properties of VZV gH. J Virol 1996; 70:8961-71. [PMID: 8971025 PMCID: PMC190993 DOI: 10.1128/jvi.70.12.8961-8971.1996] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Varicella-zoster virus (VZV) is an extremely cell-associated alphaherpesvirus; VZV infection is spread almost exclusively via cell membrane fusion. The envelope glycoprotein H (gH) is highly conserved among the herpesviruses. A virus-encoded chaperone, glycoprotein L (gL), associates with gH, and the gH:gL complex is required for gH maturation and membrane expression. We recently demonstrated that in the VZV system, the gH:gL complex facilitated cell membrane fusion and extensive polykaryon formation in transfected cells (K. M. Duus, C. Hatfield, and C. Grose, Virology 210:429-440, 1995). To further define the functions of the unusual VZV gL chaperone protein, we have performed a series of mutagenesis experiments with both gH and gL and analyzed the mutants by laser scanning confocal microscopy in a transfection-based fusion assay. We established the fact that immature gH exited the endoplasmic reticulum (ER) when coexpressed with either gE or gI and appeared on the cell surface in a patch pattern. A similar effect was observed on the cell surface with gH with a cytoplasmic tail mutagenized to closely resemble the vaccinia virus hemagglutinin cytoplasmic tail. Site-directed mutagenesis of the five gL cysteine residues demonstrated that four of five cysteines participated in the gL chaperone function required for proper maturation of gH. On the other hand, the same gL mutants facilitated transport of immature gH to the cell surface, where patching occurred. Studies of gL processing demonstrated that maturation did not require transport beyond the medial-Golgi; furthermore, gL was not detected in the outer cell membrane, nor was it secreted into the medium. Colocalization studies with 3,3'-dihexyloxa-cabocyanine iodide and N-(e-7-nitrobenz-2-oxa-1,3-diazol-4-yl-aminocaproyl)-D-erythro-sphingosine confirmed that gL was found primarily in the ER and cis/medial-Golgi when expressed alone. When all of these data were considered, they suggested a posttranslational gH:gL regulation model whereby the gL chaperone modulated gH expression via retrograde flow from the Golgi to the ER. In this schema, mature gL returns to the ER, where it escorts immature gH from the ER to the Golgi; thereafter, mature gH is transported from the trans-Golgi to the outer cell membrane, where it acts as a major fusogen.
Collapse
Affiliation(s)
- K M Duus
- Department of Microbiology, University of Iowa College of Medicine, Iowa City, USA
| | | |
Collapse
|
27
|
Pumphrey CY, Gray WL. DNA sequence of the simian varicella virus (SVV) gH gene and analysis of the SVV and varicella zoster virus gH transcripts. Virus Res 1995; 38:55-70. [PMID: 8546010 DOI: 10.1016/0168-1702(95)00049-v] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The varicella zoster virus (VZV) glycoprotein H (gH) stimulates VZV-specific immune responses and may be involved in virus penetration. This study reports the genomic map position and the DNA sequence of a simian varicella virus (SVV) homologue of the VZV gH gene. A 32P-labeled VZV gH-specific DNA probe hybridized to the HindIII B subclone of the SVV BamHI B restriction endonuclease (RE) fragment. The DNA sequence of the SVV HindIII B subclone was determined and analysis indicated a SVV open reading frame (ORF) homologous to several herpesvirus gH genes. The SVV gH ORF is 2559 base pairs in size and encodes a 852-amino acid protein. The SVV gH contains characteristics of a transmembrane glycoprotein including: 9 consensus N-linked glycosylation sites, a potential amino terminal signal sequence, and a predicted transmembrane segment located near the carboxyl terminus. The SVV and VZV gH genes exhibit 60.0% identity and the predicted polypeptides exhibit 54.5% identity. The SVV and VZV gH transcripts were analyzed and the promoter regions were compared. 32P-labeled SVV and VZV gH-specific DNA probes each hybridized to a single 2.9 kilobase transcript. The mRNA start sites of the SVV and VZV gH genes were determined by primer extension analysis, and alignment of the promoter regions indicated similar content and arrangement. The extensive conservation of SVV and VZV genes and predicted polypeptides further supports the use of SVV infection of non-human primates as a model of VZV infection of humans.
Collapse
Affiliation(s)
- C Y Pumphrey
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock 72205, USA
| | | |
Collapse
|
28
|
Klupp BG, Baumeister J, Karger A, Visser N, Mettenleiter TC. Identification and characterization of a novel structural glycoprotein in pseudorabies virus, gL. J Virol 1994; 68:3868-78. [PMID: 8189524 PMCID: PMC236892 DOI: 10.1128/jvi.68.6.3868-3878.1994] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Herpesvirus envelope glycoproteins play important roles in the interaction between virions and target cells. In the alphaherpesvirus pseudorabies virus (PrV), seven glycoproteins that all constitute homologs of glycoproteins found in herpes simplex virus type 1 (HSV-1) have been characterized, including a homolog of HSV-1 glycoprotein H (gH). Since HSV-1 gH is found associated with another essential glycoprotein, gL, we analyzed whether PrV also encodes a gL homolog. DNA sequence analysis of a corresponding part of the UL region adjacent to the internal inverted repeat in PrV strains Kaplan and Becker revealed the presence of two open reading frames (ORF). Deduced proteins exhibited homology to uracil-DNA glycosylase encoded by HSV-1 ORF UL2 (54% identity) and gL encoded by HSV-1 ORF UL1 (24% identity), respectively. To identify the PrV UL1 protein, rabbit antisera were prepared against two synthetic oligopeptides that were predicted by computer analysis to encompass antigenic epitopes. Sera against both peptides reacted in Western blots of purified virions with a 20-kDa protein. The specificity of the reaction was demonstrated by peptide competition. Since the PrV UL1 sequence did not reveal the presence of a consensus N-linked glycosylation site, concanavalin A affinity chromatography and enzymatic deglycosylation of virion glycoproteins were used to ascertain that the PrV UL1 product is O glycosylated. Therefore, we designated this protein PrV gL. Analysis of mutant PrV virions lacking gH showed that concomitantly with the absence of gH, gL was also missing in purified virions. In summary, we identified and characterized a novel structural PrV glycoprotein, gL, which represents the eighth PrV glycoprotein described. In addition, we show that virion location of PrV gL is dependent on the presence of PrV gH.
Collapse
Affiliation(s)
- B G Klupp
- Federal Research Centre for Virus Diseases of Animals, Tübingen, Germany
| | | | | | | | | |
Collapse
|
29
|
Maeda K, Kawaguchi Y, Kamiya N, Ono M, Tohya Y, Kai C, Mikami T. Identification and nucleotide sequence of a gene in feline herpesvirus type 1 homologous to the herpes simplex virus gene encoding the glycoprotein H. Arch Virol 1993; 132:183-91. [PMID: 8394688 DOI: 10.1007/bf01309852] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A gene encoding the glycoprotein H (gH) homologue of feline herpesvirus type 1 was identified and sequenced. It was located immediately downstream of the thymidine kinase gene within an EcoRI 6.6 kbp fragment. In addition, a partial UL21 homologous gene was located downstream of the gH homologous gene. The primary translation product of the gH homologous gene is predicted to consist of 821 amino acids with a molecular weight of 92.5 kDa. It possesses several characteristics typical of transmembrane glycoproteins, including a N-terminal hydrophobic signal sequence, C-terminal transmembrane domain, and putative N-linked glycosylation sites. Analysis of this protein revealed amino acid sequence homologies of 33.1% with equine herpesvirus type 1 (EHV-1) gH, 32.6% with EHV-4 gH, 29.1% with varicella-zoster virus gIII, 28.5% with pseudorabies virus gH, and 25.1% with herpes simplex virus type 1 gH. By Northern blot analysis, one of the transcripts specific for the gH homologous gene might be a mRNA of approximately 3.0 kb.
Collapse
Affiliation(s)
- K Maeda
- Department of Veterinary Microbiology, Faculty of Agriculture, University of Tokyo, Bunkyo-ku, Japan
| | | | | | | | | | | | | |
Collapse
|
30
|
Yao Z, Jackson W, Forghani B, Grose C. Varicella-zoster virus glycoprotein gpI/gpIV receptor: expression, complex formation, and antigenicity within the vaccinia virus-T7 RNA polymerase transfection system. J Virol 1993; 67:305-14. [PMID: 8380078 PMCID: PMC237364 DOI: 10.1128/jvi.67.1.305-314.1993] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The unique short region of the varicella-zoster virus (VZV) genome contains two open reading frames which encode glycoproteins designated gpI and gpIV (herpes simplex virus homologs gE and gI, respectively). Like its herpesviral counterpart gE, the VZV gpI gene product functions as a cell surface receptor (V. Litwin, W. Jackson, and C. Grose, J. Virol. 66:3643-3651, 1992). To evaluate the biosynthesis of the two VZV glycoproteins and further explore their relationship to one another, the two glycoprotein genes were individually cloned into a pTM1 vector under control of the T7 promoter. Transfection of the cloned gpI or gpIV construct into HeLa cells previously infected with vaccinia recombinant virus expressing bacteriophage T7 polymerase resulted in a much higher level expression of each VZV glycoprotein than previously achieved. Synthesis of both gpI and gpIV included intermediary partially glycosylated forms and mature N- and O-linked final product. Transfections in the presence of 32Pi demonstrated that the mature forms of both gpI and gpIV were phosphorylated, while similar experiments with [35S]sulfate showed that only the mature gpI was sulfated. When gpI and gpIV were coexpressed in the same cell, the two glycoproteins were complexed to each other, as both proteins could be immunoprecipitated by antibodies against either gpI or gpIV. Coprecipitation did not occur as a result of a shared epitope, because gpI expressed alone was not precipitated by antibody to gpIV, and gpIV expressed alone was not precipitated by antibody to gpI. Pulse-chase analysis demonstrated that the gpI-gpIV association occurred early in processing; furthermore, this complex formation interfered with posttranslational modifications and thereby reduced the M(r)s of the mature forms of both gpI and gpIV. Similarly, the molecular masses of the cotransfected gene products corresponded with those of the infected cell glycoproteins, a result which suggested that authentic gpI and gpIV were ordinarily found within a complex. Thus, the adjacent open reading frames 67 and 68 code for two glycoproteins which in turn form a distinctive sulfated and phosphorylated cell surface complex with receptor properties.
Collapse
Affiliation(s)
- Z Yao
- Department of Microbiology, University of Iowa College of Medicine, University Hospital, Iowa City 52242-1083
| | | | | | | |
Collapse
|
31
|
Klupp BG, Visser N, Mettenleiter TC. Identification and characterization of pseudorabies virus glycoprotein H. J Virol 1992; 66:3048-55. [PMID: 1313917 PMCID: PMC241065 DOI: 10.1128/jvi.66.5.3048-3055.1992] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
On the basis of DNA sequence analysis, it has recently been shown that the pseudorabies virus (PrV) genome encodes a protein homologous to glycoprotein H (gH) of other herpesviruses (B. Klupp and T.C. Mettenleiter, Virology 182:732-741, 1991). To obtain antibodies specific for gH(PrV), rabbits were immunized with synthetic peptides representing two potential epitopes on gH(PrV) as predicted by computer analysis. The antipeptide sera recognized the gH precursor polypeptide pgH translated in vitro from an in vitro-transcribed mRNA. Western blot (immunoblot) analyses of purified pseudorabies virions using these antisera revealed specific reactivity with a protein with an apparent molecular mass of 95 kDa. Specificity of the reaction could be demonstrated by competition experiments with respective peptides. Analysis of PrV deletion mutants defective in genes encoding known glycoproteins proved that gH(PrV) constitutes a novel PrV glycoprotein not previously found. Treatment of purified virion preparations with endoglycosidase H reduced the apparent molecular mass of gH(PrV) to 90 kDa, indicating the presence of N-linked high-mannose (or hybrid) carbohydrates in mature virions. Removal of all N-linked carbohydrates by N-glycosidase F resulted in a product of 76 kDa. In summary, our results demonstrate the existence of gH in PrV as a structural component of the virion.
Collapse
Affiliation(s)
- B G Klupp
- Federal Research Centre for Virus Diseases of Animals, Tübingen, Germany
| | | | | |
Collapse
|
32
|
Abstract
In the pseudorabies virus (PrV) genome a gene equivalent to the glycoprotein gH gene of other herpesviruses was identified and sequenced. It is located immediately downstream from the gene encoding PrV thymidine kinase within genomic BamHI fragments 11 and 16. Nucleotide sequencing allowed deduction of the amino acid sequence of gH. The primary translation product is predicted to comprise 686 amino acids and to exhibit a molecular weight of 71.9 kDa. It possess several characteristics typical for membrane glycoproteins, including a N-terminal hydrophobic signal sequence, C-terminal transmembrane and cytoplasmic domains, and domains with high surface probability containing three potential N-linked glycosylation sites. Comparison to other herpesvirus gH proteins revealed amino acid sequence homologies varying from 39% to gH (BHV-1), 28% to gH (HSV-1), and 19% to gH (EBV). Transcriptional analysis revealed a 2.3-kb mRNA as the gH-specific transcript. In vitro translation of either in vitro transcribed or hybrid-selected mRNA confirmed both the location of the gH gene and the size of the gH primary translation product (pgH).
Collapse
Affiliation(s)
- B G Klupp
- Federal Research Centre for Virus Diseases of Animals, Tübingen, Federal Republic of Germany
| | | |
Collapse
|
33
|
Forghani B, Dupuis KW, Schmidt NJ. Epitopes functional in neutralization of varicella-zoster virus. J Clin Microbiol 1990; 28:2500-6. [PMID: 1701445 PMCID: PMC268214 DOI: 10.1128/jcm.28.11.2500-2506.1990] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
By competition neutralization assay using monoclonal antibodies (MAbs) to varicella-zoster virus (VZV) glycoproteins (gps), we attempted to determine the topographical relationship of epitopes which are functional in VZV neutralization. MAbs against gpI interfered moderately to strongly with neutralization of MAbs against gpIII, and one antigenic domain with two distinct epitopes was identified on gpIII. Competition neutralization assays performed with MAbs to gpI revealed at least three distinct antigenic domains: the first contained two complement-dependent neutralizing epitopes; the second contained five complement-dependent neutralizing, overlapping epitopes and one nonneutralizing, nonoverlapping epitope; and the third contained one complement-enhanced neutralizing epitope. Competition neutralization assays performed with MAbs to gpIV showed one antigenic domain with two distinct epitopes which competed with nonneutralizing gpI MAbs. gpII did not interfere with neutralization of gpI, gpIII, or gpIV. Our data suggest that neutralizing and nonneutralizing MAbs can interfere with the action of viral neutralization either by inhibition or by enhancement. This report describes the epitope mapping of VZV gps by a functional biological assay.
Collapse
Affiliation(s)
- B Forghani
- Viral and Rickettsial Disease Laboratory, California State Department of Health Services, Berkeley 94704
| | | | | |
Collapse
|
34
|
Litwin V, Sandor M, Grose C. Cell surface expression of the varicella-zoster virus glycoproteins and Fc receptor. Virology 1990; 178:263-72. [PMID: 2167554 DOI: 10.1016/0042-6822(90)90402-d] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Varicella-zoster virus (VZV) specifies the synthesis of viral glycoproteins which are important antigens for induction of the host immune response. In this report the technology of laser-activated flow cytometry has been employed to measure the membrane expression of VZV glycoproteins gpI, gpII, gpIII, and gpIV. By use of biotinylated monoclonal antibodies as probes, all four glycoproteins were demonstrated on the infected cell surface. The temporal appearance of the viral glycoproteins was defined in a time course experiment and shown to be maximal about 24 hr postinfection. The issue whether VZV induces the cell surface expression of an Fc receptor (FcR) was investigated with biotinylated nonimmune human IgG, followed by streptavidin-phycoerythrin. By this technique a 10-fold increase in fluorescence intensity was seen in the VZV-infected cells as compared to the mock-infected controls. When the experiment was repeated with purified human Fc fragment rather than whole IgG, a similar degree of binding was seen. Both the VZV glycoproteins and the VZV FcR were exquisitely sensitive to trypsin treatment (1 mg/ml); likewise, the cell surface expression of these VZV products was diminished by treatment of the infected cultures with monensin, an inhibitor of glycoprotein transport. In order to prove that VZV infection was not causing the induction of a cellular Fc gamma R, the VZV-infected and mock-infected cells were stained with monoclonal antibodies directed against each of the three human cellular IgG FcR, but no differences were observed. Therefore, the FcR activity seen in the infected culture was not due to one of the known cellular Fc gamma R.
Collapse
Affiliation(s)
- V Litwin
- Department of Microbiology, University of Iowa College of Medicine, Iowa City 52242
| | | | | |
Collapse
|
35
|
Radsak K, Brücher KH, Britt W, Shiou H, Schneider D, Kollert A. Nuclear compartmentation of glycoprotein B of human cytomegalovirus. Virology 1990; 177:515-22. [PMID: 2115221 DOI: 10.1016/0042-6822(90)90516-t] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Maturation of glycoprotein B (gB) of human cytomegalovirus (HCMV) includes a series of sequential glycosylation steps followed by proteolytic cleavage of the precursor protein. Inhibitors of glycosylation and glycoprotein processing, including tunicamycin, monensin, and bromoconduritol, were used to define further the processing pathway of HCMV gB. The results of these studies indicated that cotranslational glycosylation and intracellular transport are essential for subsequent cleavage of the precursor; early trimming in the endoplasmic reticulum is not a prerequisite but facilitates this processing event. Analysis of purified nuclei with gB-specific monoclonal antibody suggested that the mannose-rich gB-precursor intermediate(s) is (are) compartmentalized in the nuclear fraction. Immunoelectron microscopy revealed that HCMV gB was localized in the outer as well as in the inner nuclear membranes of HCMV-infected fibroblasts.
Collapse
Affiliation(s)
- K Radsak
- Institut für Virologie, Philipps-Universität, Marburg, Federal Republic of Germany
| | | | | | | | | | | |
Collapse
|
36
|
Fuller AO, Santos RE, Spear PG. Neutralizing antibodies specific for glycoprotein H of herpes simplex virus permit viral attachment to cells but prevent penetration. J Virol 1989; 63:3435-43. [PMID: 2545914 PMCID: PMC250919 DOI: 10.1128/jvi.63.8.3435-3443.1989] [Citation(s) in RCA: 139] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Monoclonal antibodies specific for gH of herpes simplex virus were shown previously to neutralize viral infectivity. Results presented here demonstrate that these antibodies (at least three of them) block viral penetration without inhibiting adsorption of virus to cells. Penetration of herpes simplex virus is by fusion of the virion envelope with the plasma membrane of a susceptible cell. Electron microscopy of thin sections of cells exposed to virus revealed that neutralized virus bound to the cell surface but did not fuse with the plasma membrane. Quantitation of virus adsorption by measuring the binding of purified radiolabeled virus to cells revealed that the anti-gH antibodies had little or no effect on adsorption. Monitoring cell and viral protein synthesis after exposure of cells to infectious and neutralized virus gave results consistent with the electron microscopic finding that the anti-gH antibodies blocked viral penetration. On the basis of the results presented here and other information published elsewhere, it is suggested that gH is one of three glycoproteins essential for penetration of herpes simplex virus into cells.
Collapse
Affiliation(s)
- A O Fuller
- Department of Molecular Genetics and Cell Biology, University of Chicago, Illinois 60637
| | | | | |
Collapse
|
37
|
Sithole I, Lee LF, Velicer LF. Synthesis and processing of the Marek's disease herpesvirus B antigen glycoprotein complex. J Virol 1988; 62:4270-9. [PMID: 2845139 PMCID: PMC253861 DOI: 10.1128/jvi.62.11.4270-4279.1988] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The Marek's disease herpesvirus B antigen (MDHV-B) complex was previously immunologically identified and molecularly characterized as a set of three glycoproteins designated gp100, gp60, and gp49 on the basis of apparent molecular weight and immunoprecipitation with both polyclonal and monoclonal antibodies. Immunoprecipitation analysis, previously with polyclonal and more recently with monoclonal antibodies, of infected cell lysates labeled with [35S]methionine in the presence of tunicamycin, an inhibitor of N-linked glycosylation, revealed two putative precursor molecules of 88,000 daltons (pr88) and 44,000 daltons (pr44). High-resolution pulse-chase studies revealed that gp100 was a glycosylated intermediate which was processed to yield gp60 and gp49. This cleavage was inhibited by monensin, an inhibitor of glycoprotein processing. Endo-beta-N-acetylglucosaminidases F and H (endo-F, endo-H) reduced gp100 to pr88, indicating that the latter is an intermediate in the biosynthetic pathway. These same enzymes reduced gp49, and to a lesser extent gp60, to pr44, suggesting that pr44 is their polypeptide backbone. Significant support for this concept is the fact that the same monoclonal antibody recognized all three molecules, gp60, gp49, and pr44. In the presence of monensin, terminal addition of complex sugars was also prevented, since gp60 was replaced by a slightly faster migrating component which was insensitive to both endo-F and endo-H. Cell-free translation of infected-cell mRNA, followed by immunoprecipitation analysis with either polyclonal or monoclonal antibody, resulted in detection of a putative unglycosylated precursor polypeptide of 44,000 daltons. Since pr88 was not the initial precursor polypeptide of the MDHV-B complex, its existence may have resulted from dimerization of pr44. Again, detection of both pr88 and pr44 with the same monoclonal antibody is consistent with this interpretation. These collective data obtained from the cell-free and in vivo studies with polyclonal and monoclonal antibodies reactive with MDHV-B are consistent with the concept that pr44, the initial gene product, dimerizes to form pr88 and demonstrate that pr88 is actually a processing intermediate glycosylated to gp100, another processing intermediate, which is then processed to gp60 and gp49.
Collapse
Affiliation(s)
- I Sithole
- Department of Microbiology and Public Health, Michigan State University, East Lansing 48824-1101
| | | | | |
Collapse
|
38
|
Grose C, Giller RH. Varicella-zoster virus infection and immunization in the healthy and the immunocompromised host. Crit Rev Oncol Hematol 1988; 8:27-64. [PMID: 2832088 DOI: 10.1016/s1040-8428(88)80004-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Affiliation(s)
- C Grose
- Division of Pediatric Infectious Diseases, University of Iowa College of Medicine, Iowa City
| | | |
Collapse
|
39
|
Okazaki K, Honda E, Minetoma T, Kumagai T. Bovine herpesvirus type 1 gp87 mediates both attachment of virions to susceptible cells and hemagglutination. Arch Virol 1987; 97:297-307. [PMID: 2827610 DOI: 10.1007/bf01314428] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The 87,000-dalton glycoprotein (gp87) of bovine herpesvirus type 1 (BHV-1) was found to selectively attach to susceptible cells. The attachment of gp87 to the cells was markedly decreased by the prior adsorption of intact virions. Anti-gp87 (site Ia) monoclonal antibody, which inhibited BHV-1 adsorption to the cells and neutralized the virus without complement [Okazaki et al., Virology 250: 260-264], was effective in inhibiting the adsorption of gp87. Only the same antibody was able to inhibit the hemagglutination activity of BHV-1. Other monoclonal antibodies to the glycoproteins of BHV-1, including antibodies directed to sites Ib and Ic on gp87, were ineffective in inhibiting either virus adsorption or hemagglutination. The results of this study indicate that site Ia of gp87 molecule is the critical site of virus attachment for initiation of infection as well as the hemagglutination of BHV-1.
Collapse
Affiliation(s)
- K Okazaki
- Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | | | | | | |
Collapse
|
40
|
Montalvo EA, Grose C. Assembly and processing of the disulfide-linked varicella-zoster virus glycoprotein gpII(140). J Virol 1987; 61:2877-84. [PMID: 3039175 PMCID: PMC255809 DOI: 10.1128/jvi.61.9.2877-2884.1987] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Varicella-zoster virus (VZV) specifies the synthesis of at least four families of glycoproteins, which have been designated gpI, gpII, gpIII, and gpIV. In this report we describe the assembly and processing of VZV gpII, a structural protein of an apparent Mr of 140,000, which is the homolog of gB of herpes simplex virus. For these studies, we used two anti-gpII monoclonal antibodies which exhibited both complement-independent neutralization activity and inhibition of virus-induced cell-to-cell fusion. Pulse-chase labeling experiments identified a 124,000-Mr intermediate which was chased to the mature 140,000-Mr product when analyzed in nonreducing gels; in the presence of a reducing agent, the native gp140 was cleaved into two closely migrating species (gp66 and gp68). The biosynthesis of VZV gpII was further analyzed in the presence of the following inhibitors of glycoprotein processing: tunicamycin, monensin, castanospermine, swainsonine, and deoxymannojirimycin. All intermediate and mature forms were digested with endoglycosidases H and F, neuraminidase, and O-glycanase to further define high-mannose, complex, and O-linked glycans. Finally, the addition of sulfate residues was investigated. This characterization of VZV gpII revealed the following results. (i) gp128 and gp124 were early high-mannose forms, (ii) gp126 was an intermediate form with complex N-linked oligosaccharides, (iii) gp130 was a later intermediate with both N-linked and O-linked glycans, and (iv) the mature product gp140 contained a mixture of N-linked and O-linked glycans which were both sialated and sulfated. Further investigations indicated that gpII sulfation was inhibited by tunicamycin and castanospermine but not by deoxymannojirimycin or swainsonine. We also concluded that VZV gpII displayed many biological and biochemical properties similar to those of its herpes simplex virus homolog gB.
Collapse
|
41
|
Keller PM, Davison AJ, Lowe RS, Riemen MW, Ellis RW. Identification and sequence of the gene encoding gpIII, a major glycoprotein of varicella-zoster virus. Virology 1987; 157:526-33. [PMID: 3029986 DOI: 10.1016/0042-6822(87)90295-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The genome of varicella-zoster virus (VZV) encodes three major glycoproteins, two (gpI and gpII) having been mapped and sequenced, which carry epitopes capable of eliciting neutralizing antibodies. The product of the third major glycoprotein gene (gpIII) was purified, and seven consecutive amino acids at its N-terminus were identified. A degenerate pool of oligonucleotides based upon this sequence was used as a probe to localize the gpIII gene to the HindIII B fragment of the VZV genome. An analysis of the DNA sequence from this region revealed an open reading frame (ORF) encoding 841 amino acids. Rabbit antisera against three synthetic peptides derived from the putative gpIII gene recognized a protein which comigrated with gpIII in Western blots and immunoprecipitation analysis. Preclearing with a monoclonal antibody to gpIII specifically abolished immunoprecipitation of this protein. Also a polypeptide translated from mRNA selected by the putative gpIII gene could be immunoprecipitated by the anti-peptide sera. Therefore, we conclude that gpIII is encoded by the identified ORF in HindIII B. In addition, gpIII is implicated as essential for the cell-to-cell spread of VZV.
Collapse
|
42
|
Montalvo EA, Grose C. Varicella zoster virus glycoprotein gpI is selectively phosphorylated by a virus-induced protein kinase. Proc Natl Acad Sci U S A 1986; 83:8967-71. [PMID: 3024158 PMCID: PMC387055 DOI: 10.1073/pnas.83.23.8967] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Varicella zoster virus glycoprotein I (VZV gpI; Mr 98,000) was phosphorylated in virus-infected human cell monolayers, while two other major VZV glycoproteins (gpII and gpIII) were not similarly modified. Phosphorylation of VZV gpI was not blocked by inhibitors of glycosylation, nor were the phosphoryl groups enzymatically removed by endoglycosidases. Phosphoamino acid analysis revealed the presence of phosphoserine and phosphothreonine residues on the polypeptide backbone. The selective nature of the phosphorylation event was further demonstrated in vitro by a protein kinase (Mr 50,000), which was present in virus-infected cells but absent from uninfected cells or purified virions. The enzyme catalyzed the transfer of 32Pi from [gamma-32P]ATP to gpI but not to gpII and gpIII. Like VZV gpI, this virus-induced protein kinase was also a constituent of the plasma membrane of live VZV-infected cells.
Collapse
|