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Zhang M, Wang X, Li J, Peng F, Liu Z, Chen ZS. Ligands and receptors in human cytomegalovirus entry: Current therapies and new directions. Drug Discov Today 2024; 29:103833. [PMID: 37992888 DOI: 10.1016/j.drudis.2023.103833] [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: 08/20/2023] [Revised: 11/11/2023] [Accepted: 11/16/2023] [Indexed: 11/24/2023]
Abstract
The demand for human cytomegalovirus (HCMV) vaccines was first raised by a committee convened during the 1990s. A comprehensive investigation into the mechanism of viral infection supports the prioritization of developing drugs or vaccines that specifically target receptors and ligands involved in the infection process. As primary targets for neutralizing antibodies to combat HCMV, viral ligands (trimer, pentamer, and glycoprotein B) have crucial roles and exhibit substantial antiviral potential, which could be exploited for breakthroughs in antiviral research.
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Affiliation(s)
- Min Zhang
- School of Clinical Medicine, Weifang Medical University, Weifang 261053, China
| | - Xiaochen Wang
- Department of Medical Microbiology, Basic Medical College, Weifang Medical University, Weifang 261053, China
| | - Jianshe Li
- School of Clinical Medicine, Weifang Medical University, Weifang 261053, China
| | - Fujun Peng
- School of Basic Medical Sciences, Weifang Medical University, Weifang 261053, China.
| | - Zhijun Liu
- Department of Medical Microbiology, Basic Medical College, Weifang Medical University, Weifang 261053, China.
| | - Zhe-Sheng Chen
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St John's University, Queens, NY 11439, USA.
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2
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Penner I, Dejung M, Freiwald A, Butter F, Chen JX, Plachter B. Proteome changes of fibroblasts and endothelial cells upon incubation with human cytomegalovirus subviral Dense Bodies. Sci Data 2023; 10:517. [PMID: 37542058 PMCID: PMC10403606 DOI: 10.1038/s41597-023-02418-2] [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: 01/19/2023] [Accepted: 07/25/2023] [Indexed: 08/06/2023] Open
Abstract
Human cytomegalovirus (HCMV) is a pathogen of high medical relevance. Subviral Dense Bodies (DB) were developed as a vaccine candidate to ameliorate the severe consequences of HCMV infection. Development of such a candidate vaccine for human application requires detailed knowledge of its interaction with the host. A comprehensive mass spectrometry (MS)- based analysis was performed regarding the changes in the proteome of cell culture cells, exposed to DB.
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Affiliation(s)
- Inessa Penner
- Institute for Virology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Mario Dejung
- Institute of Molecular Biology, Johannes Gutenberg-University, Mainz, Germany
| | - Anja Freiwald
- Institute of Molecular Biology, Johannes Gutenberg-University, Mainz, Germany
| | - Falk Butter
- Institute of Molecular Biology, Johannes Gutenberg-University, Mainz, Germany
| | - Jia-Xuan Chen
- Institute of Molecular Biology, Johannes Gutenberg-University, Mainz, Germany
| | - Bodo Plachter
- Institute for Virology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany.
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3
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Penner I, Büscher N, Krauter S, Plachter B. Subviral Dense Bodies of Human Cytomegalovirus Enhance Interferon-Beta Responses in Infected Cells and Impair Progeny Production. Viruses 2023; 15:1333. [PMID: 37376632 DOI: 10.3390/v15061333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 04/18/2023] [Accepted: 06/01/2023] [Indexed: 06/29/2023] Open
Abstract
(1) Background: Infection with human cytomegalovirus (HCMV) leads to the production and release of subviral particles, termed Dense Bodies (DB). They are enclosed by a membrane resembling the viral envelope. This membrane mediates the entrance of DBs into cells in a way that is comparable to virus infection. HCMV attachment and entry trigger the induction of interferon synthesis and secretion, and the subsequent expression of interferon-regulated genes (IRGs) that might inhibit replication of the virus. Recently, we demonstrated that DBs induce a robust interferon response in the absence of infection. Little is known thus far, including how DBs influence HCMV infection and virus-host interaction. (2) Methods: Purified DBs were used to study the impact on virus replication and on the innate defense mechanisms of the cell. (3) Results: The incubation of cells with DBs at the time of infection had little effect on viral genome replication. Preincubation of DBs, however, led to a marked reduction in viral release from infected cells. These cells showed an enhancement of the cytopathic effect, associated with a moderate increase in early apoptosis. Despite virus-induced mechanisms to limit the interferon response, the induction of interferon-regulated genes (IRGs) was upregulated by DB treatment. (4) Conclusions: DBs sensitize cells against viral infection, comparable to the effects of interferons. The activities of these particles need to be considered when studying viral-host interaction.
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Affiliation(s)
- Inessa Penner
- Institute for Virology, University Medical Center of the Johannes Gutenberg-University Mainz, D-55131 Mainz, Germany
| | - Nicole Büscher
- Institute for Virology, University Medical Center of the Johannes Gutenberg-University Mainz, D-55131 Mainz, Germany
| | - Steffi Krauter
- Institute for Virology, University Medical Center of the Johannes Gutenberg-University Mainz, D-55131 Mainz, Germany
| | - Bodo Plachter
- Institute for Virology, University Medical Center of the Johannes Gutenberg-University Mainz, D-55131 Mainz, Germany
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4
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Penner I, Büscher N, Dejung M, Freiwald A, Butter F, Plachter B. Subviral Dense Bodies of Human Cytomegalovirus Induce an Antiviral Type I Interferon Response. Cells 2022; 11:cells11244028. [PMID: 36552792 PMCID: PMC9777239 DOI: 10.3390/cells11244028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 12/07/2022] [Accepted: 12/09/2022] [Indexed: 12/15/2022] Open
Abstract
(1) Background: Cells infected with the human cytomegalovirus (HCMV) produce subviral particles, termed dense bodies (DBs), both in-vitro and in-vivo. They are released from cells, comparable to infectious virions, and are enclosed by a membrane that resembles the viral envelope and mediates the entry into cells. To date, little is known about how the DB uptake influences the gene expression in target cells. The purpose of this study was to investigate the impact of DBs on cells, in the absence of a viral infection. (2) Methods: Mass spectrometry, immunoblot analyses, siRNA knockdown, and a CRISPR-CAS9 knockout, were used to investigate the changes in cellular gene expression following a DB exposure; (3) Results: A number of interferon-regulated genes (IRGs) were upregulated after the fibroblasts and endothelial cells were exposed to DBs. This upregulation was dependent on the DB entry and mediated by the type I interferon signaling through the JAK-STAT pathway. The induction of IRGs was mediated by the sensing of the DB-introduced DNA by the pattern recognition receptor cGAS. (4) Conclusions: The induction of a strong type I IFN response by DBs is a unique feature of the HCMV infection. The release of DBs may serve as a danger signal and concomitantly contribute to the induction of a strong, antiviral immune response.
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Affiliation(s)
- Inessa Penner
- Institute for Virology, University Medical Center of the Johannes Gutenberg-University, 55131 Mainz, Germany
| | - Nicole Büscher
- Institute for Virology, University Medical Center of the Johannes Gutenberg-University, 55131 Mainz, Germany
| | - Mario Dejung
- Institute for Molecular Biology, 55128 Mainz, Germany
| | - Anja Freiwald
- Institute for Molecular Biology, 55128 Mainz, Germany
| | - Falk Butter
- Institute for Molecular Biology, 55128 Mainz, Germany
| | - Bodo Plachter
- Institute for Virology, University Medical Center of the Johannes Gutenberg-University, 55131 Mainz, Germany
- Correspondence:
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5
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Krauter S, Büscher N, Bräuchle E, Ortega Iannazzo S, Penner I, Krämer N, Gogesch P, Thomas S, Kreutz M, Dejung M, Freiwald A, Butter F, Waibler Z, Plachter B. An Attenuated Strain of Human Cytomegalovirus for the Establishment of a Subviral Particle Vaccine. Vaccines (Basel) 2022; 10:vaccines10081326. [PMID: 36016214 PMCID: PMC9413975 DOI: 10.3390/vaccines10081326] [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: 07/28/2022] [Revised: 08/11/2022] [Accepted: 08/12/2022] [Indexed: 11/16/2022] Open
Abstract
Human cytomegalovirus (HCMV) infection is associated with severe disease conditions either following congenital transmission of the virus or viral reactivation in immunosuppressed individuals. Consequently, the establishment of a protective vaccine is of high medical need. Several candidates have been tested in preclinical and clinical studies, yet no vaccine has been licensed. Subviral dense bodies (DB) are a promising vaccine candidate. We have recently provided a GMP-compliant protocol for the production of DB, based on a genetically modified version of the HCMV laboratory strain Towne, expressing the pentameric complex of envelope protein gH-gL-pUL128-131 (Towne-UL130rep). In this work, we genetically attenuated Towne-UL130rep by abrogating the expression of the tegument protein pUL25 and by fusing the destabilizing domain ddFKBP to the N-terminus of the IE1- and IE2-proteins of HCMV. The resulting strain, termed TR-VAC, produced high amounts of DB under IE1/IE2 repressive conditions and concomitant supplementation of the viral terminase inhibitor letermovir to the producer cell culture. TR-VAC DB retained the capacity to induce neutralizing antibodies. A complex pattern of host protein induction was observed by mass spectrometry following exposure of primary human monocytes with TR-VAC DB. Human monocyte-derived dendritic cells (DC) moderately increased the expression of activation markers and MHC molecules upon stimulation with TR-VAC DB. In a co-culture with autologous T cells, the TR-VAC DB-stimulated DC induced a robust HCMV-specific T cell-activation and –proliferation. Exposure of donor-derived monocytic cells to DB led to the activation of a rapid innate immune response. This comprehensive data set thus shows that TR-VAC is an optimal attenuated seed virus strain for the production of a DB vaccine to be tested in clinical studies.
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Affiliation(s)
- Steffi Krauter
- Institute for Virology, University Medical Center of the Johannes Gutenberg-University Mainz, D-55131 Mainz, Germany
| | - Nicole Büscher
- Institute for Virology, University Medical Center of the Johannes Gutenberg-University Mainz, D-55131 Mainz, Germany
| | - Eric Bräuchle
- Division of Immunology, Section 3/1 “Product Testing of Immunological Biomedicines”, Paul-Ehrlich-Institut, D-63225 Langen, Germany
| | - Samira Ortega Iannazzo
- Division of Immunology, Section 3/1 “Product Testing of Immunological Biomedicines”, Paul-Ehrlich-Institut, D-63225 Langen, Germany
| | - Inessa Penner
- Institute for Virology, University Medical Center of the Johannes Gutenberg-University Mainz, D-55131 Mainz, Germany
| | - Nadine Krämer
- Institute for Virology, University Medical Center of the Johannes Gutenberg-University Mainz, D-55131 Mainz, Germany
| | - Patricia Gogesch
- Division of Immunology, Section 3/1 “Product Testing of Immunological Biomedicines”, Paul-Ehrlich-Institut, D-63225 Langen, Germany
| | - Simone Thomas
- Leibniz Institute for Immunotherapy, Regensburg and Klinik und Poliklinik für Innere Medizin III, Hämatologie und Internistische Onkologie, University Hospital Regensburg, D-93053 Regensburg, Germany
| | - Marina Kreutz
- Leibniz Institute for Immunotherapy, Regensburg and Klinik und Poliklinik für Innere Medizin III, Hämatologie und Internistische Onkologie, University Hospital Regensburg, D-93053 Regensburg, Germany
| | - Mario Dejung
- Proteomics Core Facility, Institute of Molecular Biology, D-55128 Mainz, Germany
| | - Anja Freiwald
- Proteomics Core Facility, Institute of Molecular Biology, D-55128 Mainz, Germany
| | - Falk Butter
- Proteomics Core Facility, Institute of Molecular Biology, D-55128 Mainz, Germany
| | - Zoe Waibler
- Division of Immunology, Section 3/1 “Product Testing of Immunological Biomedicines”, Paul-Ehrlich-Institut, D-63225 Langen, Germany
| | - Bodo Plachter
- Institute for Virology, University Medical Center of the Johannes Gutenberg-University Mainz, D-55131 Mainz, Germany
- Correspondence: ; Tel.: +49-6131-179232
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García-Ríos E, Rodríguez MJ, Terrón MC, Luque D, Pérez-Romero P. Identification and Characterization of Epithelial Cell-Derived Dense Bodies Produced upon Cytomegalovirus Infection. Vaccines (Basel) 2022; 10:vaccines10081308. [PMID: 36016196 PMCID: PMC9412340 DOI: 10.3390/vaccines10081308] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 08/08/2022] [Accepted: 08/11/2022] [Indexed: 11/16/2022] Open
Abstract
Dense bodies (DB) are complex, noninfectious particles produced during CMVinfection containing envelope and tegument proteins that may be ideal candidates as vaccines. Although DB were previously described in fibroblasts, no evidence of DB formation has been shown after propagating CMV in epithelial cells. In the present study, both fibroblast MRC-5 and epithelial ARPE-19 cells were used to study DB production during CMV infection. We demonstrate the formation of epithelial cell-derived DB, mostly located as cytoplasmic inclusions in the perinuclear area of the infected cell. DB were gradient-purified, and the nature of the viral particles was confirmed using CMV-specific immunelabeling. Epithelial cell-derived DB had higher density and more homogeneous size (200-300 nm) compared to fibroblast-derived DB (100-600 nm).In agreement with previous results characterizing DB from CMV-infected fibroblasts, the pp65 tegument protein was predominant in the epithelial cell-derived DB. Our results also suggest that epithelial cells had more CMV capsids in the cytoplasm and had spherical bodies compatible with nucleus condensation (pyknosis) in cells undergoing apoptosis that were not detected in MRC-5 infected cells at the tested time post-infection. Our results demonstrate the formation of DB in CMV-infected ARPE-19 epithelial cells that may be suitable candidate to develop a multiprotein vaccine with antigenic properties similar to that of the virions while not including the viral genome.
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Affiliation(s)
- Estéfani García-Ríos
- National Center for Microbiology, Instituto de Salud Carlos III, Majadahonda, 28220 Madrid, Spain
- Department of Science, Universidad Internacional de Valencia—VIU, Pintor Sorolla 21, 46002 Valencia, Spain
| | - María Josefa Rodríguez
- Electron and Confocal Microscopy Unit, Instituto de Salud Carlos III, Unidades Centrales Científico-Técnicas, Majadahonda, 28220 Madrid, Spain
| | - María Carmen Terrón
- Electron and Confocal Microscopy Unit, Instituto de Salud Carlos III, Unidades Centrales Científico-Técnicas, Majadahonda, 28220 Madrid, Spain
| | - Daniel Luque
- Electron and Confocal Microscopy Unit, Instituto de Salud Carlos III, Unidades Centrales Científico-Técnicas, Majadahonda, 28220 Madrid, Spain
- Correspondence: (D.L.); (P.P.-R.)
| | - Pilar Pérez-Romero
- National Center for Microbiology, Instituto de Salud Carlos III, Majadahonda, 28220 Madrid, Spain
- Correspondence: (D.L.); (P.P.-R.)
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7
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Gergely KM, Podlech J, Becker S, Freitag K, Krauter S, Büscher N, Holtappels R, Plachter B, Reddehase MJ, Lemmermann NAW. Therapeutic Vaccination of Hematopoietic Cell Transplantation Recipients Improves Protective CD8 T-Cell Immunotherapy of Cytomegalovirus Infection. Front Immunol 2021; 12:694588. [PMID: 34489940 PMCID: PMC8416627 DOI: 10.3389/fimmu.2021.694588] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 07/27/2021] [Indexed: 12/15/2022] Open
Abstract
Reactivation of latent cytomegalovirus (CMV) endangers the therapeutic success of hematopoietic cell transplantation (HCT) in tumor patients due to cytopathogenic virus spread that leads to organ manifestations of CMV disease, to interstitial pneumonia in particular. In cases of virus variants that are refractory to standard antiviral pharmacotherapy, immunotherapy by adoptive cell transfer (ACT) of virus-specific CD8+ T cells is the last resort to bridge the "protection gap" between hematoablative conditioning for HCT and endogenous reconstitution of antiviral immunity. We have used the well-established mouse model of CD8+ T-cell immunotherapy by ACT in a setting of experimental HCT and murine CMV (mCMV) infection to pursue the concept of improving the efficacy of ACT by therapeutic vaccination (TherVac) post-HCT. TherVac aims at restimulation and expansion of limited numbers of transferred antiviral CD8+ T cells within the recipient. Syngeneic HCT was performed with C57BL/6 mice as donors and recipients. Recipients were infected with recombinant mCMV (mCMV-SIINFEKL) that expresses antigenic peptide SIINFEKL presented to CD8+ T cells by the MHC class-I molecule Kb. ACT was performed with transgenic OT-I CD8+ T cells expressing a T-cell receptor specific for SIINFEKL-Kb. Recombinant human CMV dense bodies (DB-SIINFEKL), engineered to contain SIINFEKL within tegument protein pUL83/pp65, served for vaccination. DBs were chosen as they represent non-infectious, enveloped, and thus fusion-competent subviral particles capable of activating dendritic cells and delivering antigens directly into the cytosol for processing and presentation in the MHC class-I pathway. One set of our experiments documents the power of vaccination with DBs in protecting the immunocompetent host against a challenge infection. A further set of experiments revealed a significant improvement of antiviral control in HCT recipients by combining ACT with TherVac. In both settings, the benefit from vaccination with DBs proved to be strictly epitope-specific. The capacity to protect was lost when DBs included the peptide sequence SIINFEKA lacking immunogenicity and antigenicity due to C-terminal residue point mutation L8A, which prevents efficient proteasomal peptide processing and binding to Kb. Our preclinical research data thus provide an argument for using pre-emptive TherVac to enhance antiviral protection by ACT in HCT recipients with diagnosed CMV reactivation.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Niels A. W. Lemmermann
- Institute for Virology and Research Center for Immunotherapy (FZI) at the University Medical Center of the Johannes Gutenberg-University of Mainz, Mainz, Germany
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A disclosure of hidden secrets in human cytomegalovirus: An in-silico study of identification of novel genes and their analysis for vaccine development. Meta Gene 2020. [DOI: 10.1016/j.mgene.2020.100754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Human Cytomegalovirus Congenital (cCMV) Infection Following Primary and Nonprimary Maternal Infection: Perspectives of Prevention through Vaccine Development. Vaccines (Basel) 2020; 8:vaccines8020194. [PMID: 32340180 PMCID: PMC7349293 DOI: 10.3390/vaccines8020194] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 04/13/2020] [Accepted: 04/18/2020] [Indexed: 01/26/2023] Open
Abstract
Congenital cytomegalovirus (cCMV) might occur as a result of the human cytomegalovirus (HCMV) primary (PI) or nonprimary infection (NPI) in pregnant women. Immune correlates of protection against cCMV have been partly identified only for PI. Following either PI or NPI, HCMV strains undergo latency. From a diagnostic standpoint, while the serological criteria for the diagnosis of PI are well-established, those for the diagnosis of NPI are still incomplete. Thus far, a recombinant gB subunit vaccine has provided the best results in terms of partial protection. This partial efficacy was hypothetically attributed to the post-fusion instead of the pre-fusion conformation of the gB present in the vaccine. Future efforts should be addressed to verify whether a new recombinant gB pre-fusion vaccine would provide better results in terms of prevention of both PI and NPI. It is still a matter of debate whether human hyperimmune globulin are able to protect from HCMV vertical transmission. In conclusion, the development of an HCMV vaccine that would prevent a significant portion of PI would be a major step forward in the development of a vaccine for both PI and NPI.
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Zimmermann C, Krämer N, Krauter S, Strand D, Sehn E, Wolfrum U, Freiwald A, Butter F, Plachter B. Autophagy interferes with human cytomegalovirus genome replication, morphogenesis, and progeny release. Autophagy 2020; 17:779-795. [PMID: 32079454 DOI: 10.1080/15548627.2020.1732686] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Viral infections are often accompanied by the induction of autophagy as an intrinsic cellular defense mechanism. Herpesviruses have developed strategies to evade autophagic degradation and to manipulate autophagy of the host cells to their benefit. Here we addressed the role of macroautophagy/autophagy in human cytomegalovirus replication and for particle morphogenesis. We found that proteins of the autophagy machinery localize to cytoplasmic viral assembly compartments and enveloped virions in the cytoplasm. Surprisingly, the autophagy receptor SQSTM1/p62 was also found to colocalize with HCMV capsids in the nucleus of infected cells. This finding indicates that the autophagy machinery interacts with HCMV already at the early nuclear stages of particle morphogenesis. The membrane-bound form of LC3 and several autophagy receptors were packaged into extracellular HCMV virions. This suggested that autophagic membranes were included during secondary envelopment of HCMV virions. To further address the importance of autophagy in HCMV infection, we generated an HCMV mutant that expressed a dominant-negative version of the protease ATG4B (BAD-ATG4BC74A). The proteolytic activity of ATG4B is required for LC3 cleavage, priming it for membrane conjugation. Surprisingly, both genome replication and virus release were enhanced in cells infected with BAD-ATG4BC74A, compared to control strains. These results show that autophagy operates as an antiviral process during HCMV infection but is dispensable for secondary HCMV particle envelopment.Abbreviations: ATG: autophagy-related; BAC: bacterial artificial chromosome; BECN1: beclin 1; CPE: cytopathic effect; cVACs: cytoplasmic viral assembly compartments; d.p.i.: days post-infection; DB: dense body; EBV: Epstein-Barr virus; galK: galactokinase; HCMV: human cytomegalovirus; HFF: human foreskin fibroblasts; IE: immediate-early; IRS: internal repeat short; LC3: MAP1LC3A/B; m.o.i.; multiplicity of infection; MCP: major capsid protein; Pp: phosphoprotein; sCP/UL48a: smallest capsid protein; TRS: terminal repeat short; UL: unique long; US: unique short.
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Affiliation(s)
- Christine Zimmermann
- Institute for Virology , University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Nadine Krämer
- Institute for Virology , University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Steffi Krauter
- Institute for Virology , University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Dennis Strand
- I. Medical Clinic, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Elisabeth Sehn
- Institute of Molecular Physiology, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Uwe Wolfrum
- Institute of Molecular Physiology, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Anja Freiwald
- Institute for Molecular Biology, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Falk Butter
- Institute for Molecular Biology, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Bodo Plachter
- Institute for Virology , University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany.,Research Center for Immunotherapy (FZI), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
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11
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Koenig J, Theobald SJ, Stripecke R. Modeling Human Cytomegalovirus in Humanized Mice for Vaccine Testing. Vaccines (Basel) 2020; 8:vaccines8010089. [PMID: 32079250 PMCID: PMC7157227 DOI: 10.3390/vaccines8010089] [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] [Received: 01/31/2020] [Revised: 02/12/2020] [Accepted: 02/12/2020] [Indexed: 12/18/2022] Open
Abstract
Human cytomegalovirus (HCMV or HHV-5) is a globally spread pathogen with strictly human tropism that establishes a life-long persistence. After primary infection, high levels of long-term T and B cell responses are elicited, but the virus is not cleared. HCMV persists mainly in hematopoietic reservoirs, whereby occasional viral reactivation and spread are well controlled in immunocompetent hosts. However, when the immune system cannot control viral infections or reactivations, such as with newborns, patients with immune deficiencies, or immune-compromised patients after transplantations, the lytic outbursts can be severely debilitating or lethal. The development of vaccines for immunization of immune-compromised hosts has been challenging. Several vaccine candidates did not reach the potency expected in clinical trials and were not approved. Before anti-HCMV vaccines can be tested pre-clinically in immune-compromised hosts, reliable in vivo models recapitulating HCMV infection might accelerate their clinical translation. Therefore, immune-deficient mouse strains implanted with human cells and tissues and developing a human immune system (HIS) are being explored to test anti-HCMV vaccines. HIS-mice resemble immune-compromised hosts as they are equipped with antiviral human T and B cells, but the immune reactivity is overall low. Several groups have independently shown that HCMV infections and reactivations can be mirrored in HIS mice. However, these models and the analyses employed varied widely. The path forward is to improve human immune reconstitution and standardize the analyses of adaptive responses so that HIS models can be forthrightly used for testing novel generations of anti-HCMV vaccines in the preclinical pipeline.
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Affiliation(s)
- Johannes Koenig
- Laboratory of Regenerative Immune Therapies Applied, Excellence Cluster REBIRTH, Hannover Medical School, 30625 Hannover, Germany; (J.K.); (S.J.T.)
- Clinic of Hematology, Hemostasis, Oncology and Stem Cell Transplantation, Hannover Medical School, 30625 Hannover, Germany
- German Center for Infection Research (DZIF), Partner Site Hannover-Braunschweig, 30625 Hannover, Germany
| | - Sebastian J. Theobald
- Laboratory of Regenerative Immune Therapies Applied, Excellence Cluster REBIRTH, Hannover Medical School, 30625 Hannover, Germany; (J.K.); (S.J.T.)
- Clinic of Hematology, Hemostasis, Oncology and Stem Cell Transplantation, Hannover Medical School, 30625 Hannover, Germany
- German Center for Infection Research (DZIF), Partner Site Hannover-Braunschweig, 30625 Hannover, Germany
| | - Renata Stripecke
- Laboratory of Regenerative Immune Therapies Applied, Excellence Cluster REBIRTH, Hannover Medical School, 30625 Hannover, Germany; (J.K.); (S.J.T.)
- Clinic of Hematology, Hemostasis, Oncology and Stem Cell Transplantation, Hannover Medical School, 30625 Hannover, Germany
- German Center for Infection Research (DZIF), Partner Site Hannover-Braunschweig, 30625 Hannover, Germany
- Correspondence: ; Tel.: +49-(511)-532-6999; Fax: +49-(511)-532-6975
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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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Production Strategies for Pentamer-Positive Subviral Dense Bodies as a Safe Human Cytomegalovirus Vaccine. Vaccines (Basel) 2019; 7:vaccines7030104. [PMID: 31480520 PMCID: PMC6789746 DOI: 10.3390/vaccines7030104] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 08/26/2019] [Accepted: 08/28/2019] [Indexed: 12/12/2022] Open
Abstract
Infections with the human cytomegalovirus (HCMV) are associated with severe clinical manifestations in children following prenatal transmission and after viral reactivation in immunosuppressed individuals. The development of an HCMV vaccine has long been requested but there is still no licensed product available. Subviral dense bodies (DB) are immunogenic in pre-clinical models and are thus a promising HCMV vaccine candidate. Recently, we established a virus based on the laboratory strain Towne that synthesizes large numbers of DB containing the pentameric protein complex gH/gL/UL128-131 (Towne-UL130repΔGFP). The work presented here focuses on providing strategies for the production of a safe vaccine based on that strain. A GMP-compliant protocol for DB production was established. Furthermore, the DB producer strain Towne-UL130rep was attenuated by deleting the UL25 open reading frame. Additional genetic modifications aim to abrogate its capacity to replicate in vivo by conditionally expressing pUL51 using the Shield-1/FKBP destabilization system. We further show that the terminase inhibitor letermovir can be used to reduce infectious virus contamination of a DB vaccine by more than two orders of magnitude. Taken together, strategies are provided here that allow for the production of a safe and immunogenic DB vaccine for clinical testing.
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