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Dynesen LT, Fernandez I, Coquin Y, Delaplace M, Montange T, Njouom R, Bilounga-Ndongo C, Rey FA, Gessain A, Backovic M, Buseyne F. Neutralization of zoonotic retroviruses by human antibodies: Genotype-specific epitopes within the receptor-binding domain from simian foamy virus. PLoS Pathog 2023; 19:e1011339. [PMID: 37093892 PMCID: PMC10159361 DOI: 10.1371/journal.ppat.1011339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 05/04/2023] [Accepted: 03/31/2023] [Indexed: 04/25/2023] Open
Abstract
Infection with viruses of animal origin pose a significant threat to human populations. Simian foamy viruses (SFVs) are frequently transmitted to humans, in which they establish a life-long infection, with the persistence of replication-competent virus. However, zoonotic SFVs do not induce severe disease nor are they transmitted between humans. Thus, SFVs represent a model of zoonotic retroviruses that lead to a chronic infection successfully controlled by the human immune system. We previously showed that infected humans develop potent neutralizing antibodies (nAbs). Within the viral envelope (Env), the surface protein (SU) carries a variable region that defines two genotypes, overlaps with the receptor binding domain (RBD), and is the exclusive target of nAbs. However, its antigenic determinants are not understood. Here, we characterized nAbs present in plasma samples from SFV-infected individuals living in Central Africa. Neutralization assays were carried out in the presence of recombinant SU that compete with SU at the surface of viral vector particles. We defined the regions targeted by the nAbs using mutant SU proteins modified at the glycosylation sites, RBD functional subregions, and genotype-specific sequences that present properties of B-cell epitopes. We observed that nAbs target conformational epitopes. We identified three major epitopic regions: the loops at the apex of the RBD, which likely mediate interactions between Env protomers to form Env trimers, a loop located in the vicinity of the heparan binding site, and a region proximal to the highly conserved glycosylation site N8. We provide information on how nAbs specific for each of the two viral genotypes target different epitopes. Two common immune escape mechanisms, sequence variation and glycan shielding, were not observed. We propose a model according to which the neutralization mechanisms rely on the nAbs to block the Env conformational change and/or interfere with binding to susceptible cells. As the SFV RBD is structurally different from known retroviral RBDs, our data provide fundamental knowledge on the structural basis for the inhibition of viruses by nAbs. Trial registration: The study was registered at www.clinicaltrials.gov: https://clinicaltrials.gov/ct2/show/NCT03225794/.
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Affiliation(s)
- Lasse Toftdal Dynesen
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Unité d'épidémiologie et Physiopathologie des Virus Oncogènes, Paris, France
| | - Ignacio Fernandez
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Unité de Virologie Structurale, Paris, France
| | - Youna Coquin
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Unité d'épidémiologie et Physiopathologie des Virus Oncogènes, Paris, France
| | - Manon Delaplace
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Unité d'épidémiologie et Physiopathologie des Virus Oncogènes, Paris, France
| | - Thomas Montange
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Unité d'épidémiologie et Physiopathologie des Virus Oncogènes, Paris, France
| | | | | | - Félix A Rey
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Unité de Virologie Structurale, Paris, France
| | - Antoine Gessain
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Unité d'épidémiologie et Physiopathologie des Virus Oncogènes, Paris, France
| | - Marija Backovic
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Unité de Virologie Structurale, Paris, France
| | - Florence Buseyne
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Unité d'épidémiologie et Physiopathologie des Virus Oncogènes, Paris, France
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Munz CM, Kreher H, Erdbeer A, Richter S, Westphal D, Yi B, Behrendt R, Stanke N, Lindel F, Lindemann D. Efficient production of inhibitor-free foamy virus glycoprotein-containing retroviral vectors by proteoglycan-deficient packaging cells. Mol Ther Methods Clin Dev 2022; 26:394-412. [PMID: 36034773 PMCID: PMC9388887 DOI: 10.1016/j.omtm.2022.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Accepted: 07/07/2022] [Indexed: 11/21/2022]
Abstract
Foamy viruses (FVs) or heterologous retroviruses pseudotyped with FV glycoprotein enable transduction of a great variety of target tissues of disparate species. Specific cellular entry receptors responsible for this exceptionally broad tropism await their identification. Though, ubiquitously expressed heparan sulfate proteoglycan (HS-PG) is known to serve as an attachment factor of FV envelope (Env)-containing virus particles, greatly enhancing target cell permissiveness. Production of high-titer, FV Env-containing retroviral vectors is strongly dependent on the use of cationic polymer-based transfection reagents like polyethyleneimine (PEI). We identified packaging cell-surface HS-PG expression to be responsible for this requirement. Efficient release of FV Env-containing virus particles necessitates neutralization of HS-PG binding sites by PEI. Remarkably, remnants of PEI in FV Env-containing vector supernatants, which are not easily removable, negatively impact target cell transduction, in particular those of myeloid and lymphoid origin. To overcome this limitation for production of FV Env-containing retrovirus supernatants, we generated 293T-based packaging cell lines devoid of HS-PG by genome engineering. This enabled, for the first, time production of inhibitor-free, high-titer FV Env-containing virus supernatants by non-cationic polymer-mediated transfection. Depending on the type of virus, produced titers were 2- to 10-fold higher compared with those obtained by PEI transfection.
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Affiliation(s)
- Clara Marie Munz
- Institute of Medical Microbiology and Virology, University Hospital and Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany
| | - Henriette Kreher
- Institute of Medical Microbiology and Virology, University Hospital and Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany
| | - Alexander Erdbeer
- Institute of Medical Microbiology and Virology, University Hospital and Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany
| | - Stefanie Richter
- Institute of Medical Microbiology and Virology, University Hospital and Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany
- Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, 01307 Dresden, Germany
| | - Dana Westphal
- Institute of Medical Microbiology and Virology, University Hospital and Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany
| | - Buqing Yi
- Institute of Medical Microbiology and Virology, University Hospital and Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany
| | - Rayk Behrendt
- Institute of Immunology, Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, 01307 Dresden, Germany
| | - Nicole Stanke
- Institute of Medical Microbiology and Virology, University Hospital and Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany
- Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, 01307 Dresden, Germany
| | - Fabian Lindel
- Institute of Medical Microbiology and Virology, University Hospital and Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany
- Corresponding author Fabian Lindel,Cell line Screening & Development (CLSD), Novartis Institutes for BioMedical Research (NIBR), WSJ-360, Kohlenstrasse, 4056 Basel, Switzerland.
| | - Dirk Lindemann
- Institute of Medical Microbiology and Virology, University Hospital and Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany
- Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, 01307 Dresden, Germany
- Corresponding author Dirk Lindemann, Institute of Medical Microbiology and Virology, University Hospital and Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany.
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Couteaudier M, Montange T, Njouom R, Bilounga-Ndongo C, Gessain A, Buseyne F. Plasma antibodies from humans infected with zoonotic simian foamy virus do not inhibit cell-to-cell transmission of the virus despite binding to the surface of infected cells. PLoS Pathog 2022; 18:e1010470. [PMID: 35605011 PMCID: PMC9166401 DOI: 10.1371/journal.ppat.1010470] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 06/03/2022] [Accepted: 03/25/2022] [Indexed: 01/23/2023] Open
Abstract
Zoonotic simian foamy viruses (SFV) establish lifelong infection in their human hosts. Despite repeated transmission of SFV from nonhuman primates to humans, neither transmission between human hosts nor severe clinical manifestations have been reported. We aim to study the immune responses elicited by chronic infection with this retrovirus and previously reported that SFV-infected individuals generate potent neutralizing antibodies that block cell infection by viral particles. Here, we assessed whether human plasma antibodies block SFV cell-to-cell transmission and present the first description of cell-to-cell spreading of zoonotic gorilla SFV. We set-up a microtitration assay to quantify the ability of plasma samples from 20 Central African individuals infected with gorilla SFV and 9 uninfected controls to block cell-associated transmission of zoonotic gorilla SFV strains. We used flow-based cell cytometry and fluorescence microscopy to study envelope protein (Env) localization and the capacity of plasma antibodies to bind to infected cells. We visualized the cell-to-cell spread of SFV by real-time live imaging of a GFP-expressing prototype foamy virus (CI-PFV) strain. None of the samples neutralized cell-associated SFV infection, despite the inhibition of cell-free virus. We detected gorilla SFV Env in the perinuclear region, cytoplasmic vesicles and at the cell surface. We found that plasma antibodies bind to Env located at the surface of cells infected with primary gorilla SFV strains. Extracellular labeling of SFV proteins by human plasma samples showed patchy staining at the base of the cell and dense continuous staining at the cell apex, as well as staining in the intercellular connections that formed when previously connected cells separated from each other. In conclusion, SFV-specific antibodies from infected humans do not block cell-to-cell transmission, at least in vitro, despite their capacity to bind to the surface of infected cells. Trial registration: Clinical trial registration: www.clinicaltrials.gov, https://clinicaltrials.gov/ct2/show/NCT03225794/. Foamy viruses are the oldest known retroviruses and have been mostly described to be nonpathogenic in their natural animal hosts. Simian foamy viruses (SFVs) can be transmitted to humans, in whom they establish persistent infection, as have the simian viruses that led to the emergence of two major human pathogens, human immunodeficiency virus type 1 (HIV-1) and human T lymphotropic virus type 1 (HTLV-1). Such cross-species transmission of SFV is ongoing in many parts of the world where humans have contact with nonhuman primates. We previously showed high titers of neutralizing antibodies in the plasma of most SFV-infected individuals. These antiviral antibodies can inhibit cell-free virus entry. However, SFV efficiently spread from one cell to another. Here, we demonstrate that plasma antibodies do not block such cell-to-cell transmission, despite their capacity to bind to the surface of infected cells. In addition, we document for the first time the cell-to-cell spread of primary zoonotic gorilla SFV.
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Affiliation(s)
- Mathilde Couteaudier
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Unité d’Epidémiologie et Physiopathologie des Virus Oncogènes, Paris, France
| | - Thomas Montange
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Unité d’Epidémiologie et Physiopathologie des Virus Oncogènes, Paris, France
| | | | | | - Antoine Gessain
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Unité d’Epidémiologie et Physiopathologie des Virus Oncogènes, Paris, France
| | - Florence Buseyne
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Unité d’Epidémiologie et Physiopathologie des Virus Oncogènes, Paris, France
- * E-mail:
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Jaguva Vasudevan AA, Becker D, Luedde T, Gohlke H, Münk C. Foamy Viruses, Bet, and APOBEC3 Restriction. Viruses 2021; 13:504. [PMID: 33803830 PMCID: PMC8003144 DOI: 10.3390/v13030504] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/10/2021] [Accepted: 03/16/2021] [Indexed: 01/24/2023] Open
Abstract
Non-human primates (NHP) are an important source of viruses that can spillover to humans and, after adaptation, spread through the host population. Whereas HIV-1 and HTLV-1 emerged as retroviral pathogens in humans, a unique class of retroviruses called foamy viruses (FV) with zoonotic potential are occasionally detected in bushmeat hunters or zookeepers. Various FVs are endemic in numerous mammalian natural hosts, such as primates, felines, bovines, and equines, and other animals, but not in humans. They are apathogenic, and significant differences exist between the viral life cycles of FV and other retroviruses. Importantly, FVs replicate in the presence of many well-defined retroviral restriction factors such as TRIM5α, BST2 (Tetherin), MX2, and APOBEC3 (A3). While the interaction of A3s with HIV-1 is well studied, the escape mechanisms of FVs from restriction by A3 is much less explored. Here we review the current knowledge of FV biology, host restriction factors, and FV-host interactions with an emphasis on the consequences of FV regulatory protein Bet binding to A3s and outline crucial open questions for future studies.
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Affiliation(s)
- Ananda Ayyappan Jaguva Vasudevan
- Clinic for Gastroenterology, Hepatology and Infectiology, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany;
| | - Daniel Becker
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (D.B.); (H.G.)
| | - Tom Luedde
- Clinic for Gastroenterology, Hepatology and Infectiology, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany;
| | - Holger Gohlke
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (D.B.); (H.G.)
- John von Neumann Institute for Computing (NIC), Jülich Supercomputing Centre & Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Carsten Münk
- Clinic for Gastroenterology, Hepatology and Infectiology, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany;
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