1
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Zehner M, Alt M, Ashurov A, Goldsmith JA, Spies R, Weiler N, Lerma J, Gieselmann L, Stöhr D, Gruell H, Schultz EP, Kreer C, Schlachter L, Janicki H, Laib Sampaio K, Stegmann C, Nemetchek MD, Dähling S, Ullrich L, Dittmer U, Witzke O, Koch M, Ryckman BJ, Lotfi R, McLellan JS, Krawczyk A, Sinzger C, Klein F. Single-cell analysis of memory B cells from top neutralizers reveals multiple sites of vulnerability within HCMV Trimer and Pentamer. Immunity 2023; 56:2602-2620.e10. [PMID: 37967532 DOI: 10.1016/j.immuni.2023.10.009] [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: 03/23/2023] [Revised: 07/02/2023] [Accepted: 10/18/2023] [Indexed: 11/17/2023]
Abstract
Human cytomegalovirus (HCMV) can cause severe diseases in fetuses, newborns, and immunocompromised individuals. Currently, no vaccines are approved, and treatment options are limited. Here, we analyzed the human B cell response of four HCMV top neutralizers from a cohort of 9,000 individuals. By single-cell analyses of memory B cells targeting the pentameric and trimeric HCMV surface complexes, we identified vulnerable sites on the shared gH/gL subunits as well as complex-specific subunits UL128/130/131A and gO. Using high-resolution cryogenic electron microscopy, we revealed the structural basis of the neutralization mechanisms of antibodies targeting various binding sites. Moreover, we identified highly potent antibodies that neutralized a broad spectrum of HCMV strains, including primary clinical isolates, that outperform known antibodies used in clinical trials. Our study provides a deep understanding of the mechanisms of HCMV neutralization and identifies promising antibody candidates to prevent and treat HCMV infection.
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Affiliation(s)
- Matthias Zehner
- Laboratory of Experimental Immunology, Institute of Virology, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany.
| | - Mira Alt
- Department of Infectious Diseases, West German Centre of Infectious Diseases, University Hospital Essen, University Duisburg-Essen, 45147 Essen, Germany
| | - Artem Ashurov
- Laboratory of Experimental Immunology, Institute of Virology, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany
| | - Jory A Goldsmith
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | - Rebecca Spies
- Institute for Virology, Ulm University Medical Center, 89081 Ulm, Germany
| | - Nina Weiler
- Institute for Virology, Ulm University Medical Center, 89081 Ulm, Germany
| | - Justin Lerma
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | - Lutz Gieselmann
- Laboratory of Experimental Immunology, Institute of Virology, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany; German Center for Infection Research, Partner Site Bonn-Cologne, 50931 Cologne, Germany
| | - Dagmar Stöhr
- Institute for Virology, Ulm University Medical Center, 89081 Ulm, Germany
| | - Henning Gruell
- Laboratory of Experimental Immunology, Institute of Virology, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany
| | - Eric P Schultz
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA; Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, MT 59812, USA
| | - Christoph Kreer
- Laboratory of Experimental Immunology, Institute of Virology, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany
| | - Linda Schlachter
- Laboratory of Experimental Immunology, Institute of Virology, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany
| | - Hanna Janicki
- Laboratory of Experimental Immunology, Institute of Virology, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany
| | | | - Cora Stegmann
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA; Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, MT 59812, USA
| | - Michelle D Nemetchek
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA; Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, MT 59812, USA
| | - Sabrina Dähling
- Laboratory of Experimental Immunology, Institute of Virology, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany
| | - Leon Ullrich
- Laboratory of Experimental Immunology, Institute of Virology, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany
| | - Ulf Dittmer
- Institute for Virology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
| | - Oliver Witzke
- Department of Infectious Diseases, West German Centre of Infectious Diseases, University Hospital Essen, University Duisburg-Essen, 45147 Essen, Germany
| | - Manuel Koch
- Institute for Dental Research and Oral Musculoskeletal Biology, Center for Biochemistry, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany
| | - Brent J Ryckman
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA; Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, MT 59812, USA
| | - Ramin Lotfi
- Institute for Transfusion Medicine, Ulm University Medical Center, 89081 Ulm, Germany
| | - Jason S McLellan
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | - Adalbert Krawczyk
- Department of Infectious Diseases, West German Centre of Infectious Diseases, University Hospital Essen, University Duisburg-Essen, 45147 Essen, Germany; Institute for Virology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
| | - Christian Sinzger
- Institute for Virology, Ulm University Medical Center, 89081 Ulm, Germany
| | - Florian Klein
- Laboratory of Experimental Immunology, Institute of Virology, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany; German Center for Infection Research, Partner Site Bonn-Cologne, 50931 Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University Hospital of Cologne, 50931 Cologne, Germany.
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2
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Flomm FJ, Soh TK, Schneider C, Wedemann L, Britt HM, Thalassinos K, Pfitzner S, Reimer R, Grünewald K, Bosse JB. Intermittent bulk release of human cytomegalovirus. PLoS Pathog 2022; 18:e1010575. [PMID: 35925870 PMCID: PMC9352052 DOI: 10.1371/journal.ppat.1010575] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 05/06/2022] [Indexed: 01/24/2023] Open
Abstract
Human Cytomegalovirus (HCMV) can infect a variety of cell types by using virions of varying glycoprotein compositions. It is still unclear how this diversity is generated, but spatio-temporally separated envelopment and egress pathways might play a role. So far, one egress pathway has been described in which HCMV particles are individually enveloped into small vesicles and are subsequently exocytosed continuously. However, some studies have also found enveloped virus particles inside multivesicular structures but could not link them to productive egress or degradation pathways. We used a novel 3D-CLEM workflow allowing us to investigate these structures in HCMV morphogenesis and egress at high spatio-temporal resolution. We found that multiple envelopment events occurred at individual vesicles leading to multiviral bodies (MViBs), which subsequently traversed the cytoplasm to release virions as intermittent bulk pulses at the plasma membrane to form extracellular virus accumulations (EVAs). Our data support the existence of a novel bona fide HCMV egress pathway, which opens the gate to evaluate divergent egress pathways in generating virion diversity.
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Affiliation(s)
- Felix J. Flomm
- Centre for Structural Systems Biology, Hamburg, Germany
- Hannover Medical School, Institute of Virology, Hannover, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
- Leibniz-Institute of Virology (LIV), Hamburg, Germany
| | - Timothy K. Soh
- Centre for Structural Systems Biology, Hamburg, Germany
- Hannover Medical School, Institute of Virology, Hannover, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
- Leibniz-Institute of Virology (LIV), Hamburg, Germany
| | | | - Linda Wedemann
- Centre for Structural Systems Biology, Hamburg, Germany
- Hannover Medical School, Institute of Virology, Hannover, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
- Leibniz-Institute of Virology (LIV), Hamburg, Germany
| | - Hannah M. Britt
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Konstantinos Thalassinos
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
- Institute of Structural and Molecular Biology, Birkbeck College, University of London, London, United Kingdom
| | | | | | - Kay Grünewald
- Centre for Structural Systems Biology, Hamburg, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
- Leibniz-Institute of Virology (LIV), Hamburg, Germany
- University of Hamburg, Department of Chemistry, Hamburg, Germany
| | - Jens B. Bosse
- Centre for Structural Systems Biology, Hamburg, Germany
- Hannover Medical School, Institute of Virology, Hannover, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
- Leibniz-Institute of Virology (LIV), Hamburg, Germany
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3
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Braun B, Laib Sampaio K, Kuderna AK, Widmann M, Sinzger C. Viral and Cellular Factors Contributing to the Hematogenous Dissemination of Human Cytomegalovirus via Polymorphonuclear Leukocytes. Viruses 2022; 14:v14071561. [PMID: 35891541 PMCID: PMC9323586 DOI: 10.3390/v14071561] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 07/12/2022] [Accepted: 07/16/2022] [Indexed: 02/06/2023] Open
Abstract
Polymorphonuclear leukocytes (PMNs) presumably transmit human cytomegalovirus (HCMV) between endothelial cells in blood vessels and thereby facilitate spread to peripheral organs. We aimed to identify viral components that contribute to PMN-mediated transmission and test the hypothesis that cellular adhesion molecules shield transmission sites from entry inhibitors. Stop codons were introduced into the genome of HCMV strain Merlin to delete pUL74 of the trimeric and pUL128 of the pentameric glycoprotein complex and the tegument proteins pp65 and pp71. Mutants were analyzed regarding virus uptake by PMNs and transfer of infection to endothelial cells. Cellular adhesion molecules were evaluated for their contribution to virus transmission using function-blocking antibodies, and hits were further analyzed regarding shielding against inhibitors of virus entry. The viral proteins pUL128, pp65, and pp71 were required for efficient PMN-mediated transmission, whereas pUL74 was dispensable. On the cellular side, the blocking of the αLβ2-integrin LFA-1 reduced virus transfer by 50% and allowed entry inhibitors to reduce it further by 30%. In conclusion, these data show that PMN-mediated transmission depends on the pentameric complex and an intact tegument and supports the idea of a virological synapse that promotes this dissemination mode both directly and via immune evasion.
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4
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Le MH, Taghuo-Kaptouom E, Schrader T. Molecular Tweezers – a new class of potent broad-spectrum antivirals against enveloped viruses. Chem Commun (Camb) 2022; 58:2954-2966. [DOI: 10.1039/d1cc06737k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new supramolecular approach to broad spectrum antivirals utilizes host guest chemistry between molecular tweezers and lysine/arginine as well as choline. Basic amino acids in amyloid-forming SEVI peptides (semen-derived enhancers...
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5
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Vlahava VM, Murrell I, Zhuang L, Aicheler RJ, Lim E, Miners KL, Ladell K, Suárez NM, Price DA, Davison AJ, Wilkinson GW, Wills MR, Weekes MP, Wang EC, Stanton RJ. Monoclonal antibodies targeting nonstructural viral antigens can activate ADCC against human cytomegalovirus. J Clin Invest 2021; 131:139296. [PMID: 33586678 PMCID: PMC7880312 DOI: 10.1172/jci139296] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 09/16/2020] [Indexed: 12/16/2022] Open
Abstract
Human cytomegalovirus (HCMV) is a ubiquitous pathogen that causes severe disease following congenital infection and in immunocompromised individuals. No vaccines are licensed, and there are limited treatment options. We now show that the addition of anti-HCMV antibodies (Abs) can activate NK cells prior to the production of new virions, through Ab-dependent cellular cytotoxicity (ADCC), overcoming viral immune evasins. Quantitative proteomics defined the most abundant HCMV proteins on the cell surface, and we screened these targets to identify the viral antigens responsible for activating ADCC. Surprisingly, these were not structural glycoproteins; instead, the immune evasins US28, RL11, UL5, UL141, and UL16 each individually primed ADCC. We isolated human monoclonal Abs (mAbs) specific for UL16 or UL141 from a seropositive donor and optimized them for ADCC. Cloned Abs targeting a single antigen (UL141) were sufficient to mediate ADCC against HCMV-infected cells, even at low concentrations. Collectively, these findings validated an unbiased methodological approach to the identification of immunodominant viral antigens, providing a pathway toward an immunotherapeutic strategy against HCMV and potentially other pathogens.
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Affiliation(s)
- Virginia-Maria Vlahava
- Division of Infection and Immunology, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Isa Murrell
- Division of Infection and Immunology, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Lihui Zhuang
- Division of Infection and Immunology, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | | | - Eleanor Lim
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Kelly L Miners
- Division of Infection and Immunology, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Kristin Ladell
- Division of Infection and Immunology, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Nicolás M Suárez
- University of Glasgow-MRC Centre for Virus Research, Glasgow, United Kingdom
| | - David A Price
- Division of Infection and Immunology, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Andrew J Davison
- University of Glasgow-MRC Centre for Virus Research, Glasgow, United Kingdom
| | - Gavin Wg Wilkinson
- Division of Infection and Immunology, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Mark R Wills
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Michael P Weekes
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Eddie Cy Wang
- Division of Infection and Immunology, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Richard J Stanton
- Division of Infection and Immunology, School of Medicine, Cardiff University, Cardiff, United Kingdom
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6
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Peptide Derivatives of Platelet-Derived Growth Factor Receptor Alpha Inhibit Cell-Associated Spread of Human Cytomegalovirus. Viruses 2021; 13:v13091780. [PMID: 34578361 PMCID: PMC8473290 DOI: 10.3390/v13091780] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 08/26/2021] [Accepted: 09/01/2021] [Indexed: 12/27/2022] Open
Abstract
Cell-free human cytomegalovirus (HCMV) can be inhibited by a soluble form of the cellular HCMV-receptor PDGFRα, resembling neutralization by antibodies. The cell-associated growth of recent HCMV isolates, however, is resistant against antibodies. We investigated whether PDGFRα-derivatives can inhibit this transmission mode. A protein containing the extracellular PDGFRα-domain and 40-mer peptides derived therefrom were tested regarding the inhibition of the cell-associated HCMV strain Merlin-pAL1502, hits were validated with recent isolates, and the most effective peptide was modified to increase its potency. The modified peptide was further analyzed regarding its mode of action on the virion level. While full-length PDGFRα failed to inhibit HCMV isolates, three peptides significantly reduced virus growth. A 30-mer version of the lead peptide (GD30) proved even more effective against the cell-free virus, and this effect was HCMV-specific and depended on the viral glycoprotein O. In cell-associated spread, GD30 reduced both the number of transferred particles and their penetration. This effect was reversible after peptide removal, which allowed the synchronized analysis of particle transfer, showing that two virions per hour were transferred to neighboring cells and one virion was sufficient for infection. In conclusion, PDGFRα-derived peptides are novel inhibitors of the cell-associated spread of HCMV and facilitate the investigation of this transmission mode.
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7
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Brenner S, Braun B, Read C, Weil T, Walther P, Schrader T, Münch J, von Einem J. The Molecular Tweezer CLR01 Inhibits Antibody-Resistant Cell-to-Cell Spread of Human Cytomegalovirus. Viruses 2021; 13:v13091685. [PMID: 34578265 PMCID: PMC8472163 DOI: 10.3390/v13091685] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 08/20/2021] [Accepted: 08/23/2021] [Indexed: 02/06/2023] Open
Abstract
Human cytomegalovirus (HCMV) uses two major ways for virus dissemination: infection by cell-free virus and direct cell-to-cell spread. Neutralizing antibodies can efficiently inhibit infection by cell-free virus but mostly fail to prevent cell-to-cell transmission. Here, we show that the ‘molecular tweezer’ CLR01, a broad-spectrum antiviral agent, is not only highly active against infection with cell-free virus but most remarkably inhibits antibody-resistant direct cell-to-cell spread of HCMV. The inhibition of cell-to-cell spread by CLR01 was not limited to HCMV but was also shown for the alphaherpesviruses herpes simplex viruses 1 and 2 (HSV-1, -2). CLR01 is a rapid acting small molecule that inhibits HCMV entry at the attachment and penetration steps. Electron microscopy of extracellular virus particles indicated damage of the viral envelope by CLR01, which likely impairs the infectivity of virus particles. The rapid inactivation of viral particles by CLR01, the viral envelope as the main target, and the inhibition of virus entry at different stages are presumably the key to inhibition of cell-free virus infection and cell-to-cell spread by CLR01. Importance: While cell-free spread enables the human cytomegalovirus (HCMV) and other herpesviruses to transmit between hosts, direct cell-to-cell spread is thought to be more relevant for in vivo dissemination within infected tissues. Cell-to-cell spread is resistant to neutralizing antibodies, thus contributing to the maintenance of virus infection and virus dissemination in the presence of an intact immune system. Therefore, it would be therapeutically interesting to target this mode of spread in order to treat severe HCMV infections and to prevent dissemination of virus within the infected host. The molecular tweezer CLR01 exhibits broad-spectrum antiviral activity against a number of enveloped viruses and efficiently blocks antibody-resistant cell-to-cell spread of HCMV, thus representing a novel class of small molecules with promising antiviral activity.
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Affiliation(s)
- Sina Brenner
- Institute of Virology, Ulm University Medical Center, 89081 Ulm, Germany; (S.B.); (B.B.); (C.R.)
| | - Berenike Braun
- Institute of Virology, Ulm University Medical Center, 89081 Ulm, Germany; (S.B.); (B.B.); (C.R.)
| | - Clarissa Read
- Institute of Virology, Ulm University Medical Center, 89081 Ulm, Germany; (S.B.); (B.B.); (C.R.)
- Central Facility for Electron Microscopy, Ulm University, 89081 Ulm, Germany;
| | - Tatjana Weil
- Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany; (T.W.); (J.M.)
| | - Paul Walther
- Central Facility for Electron Microscopy, Ulm University, 89081 Ulm, Germany;
| | - Thomas Schrader
- Faculty of Chemistry, University of Duisburg-Essen, 45117 Essen, Germany;
| | - Jan Münch
- Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany; (T.W.); (J.M.)
- Core Facility Functional Peptidomics, Ulm University Medical Center, 89081 Ulm, Germany
| | - Jens von Einem
- Institute of Virology, Ulm University Medical Center, 89081 Ulm, Germany; (S.B.); (B.B.); (C.R.)
- Correspondence: ; Tel.: +49-(0)731-500-65104; Fax: +49-(0)731-500-65102
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8
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Braun B, Sinzger C. Transmission of cell-associated human cytomegalovirus isolates between various cell types using polymorphonuclear leukocytes as a vehicle. Med Microbiol Immunol 2021; 210:197-209. [PMID: 34091753 PMCID: PMC8286230 DOI: 10.1007/s00430-021-00713-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 05/15/2021] [Indexed: 12/25/2022]
Abstract
Polymorphonuclear leukocytes (PMNs) are regarded as vehicles for the hematogenous dissemination of human cytomegalovirus (HCMV). In cell culture, this concept has been validated with cell-free laboratory strains but not yet with clinical HCMV isolates that grow strictly cell-associated. We, therefore, aimed to evaluate whether PMNs can also transmit such isolates from initially infected fibroblasts to other cell types, which might further clarify the role of PMNs in HCMV dissemination and provide a model to search for potential inhibitors. PMNs, which have been isolated from HCMV-seronegative individuals, were added for 3 h to fibroblasts infected with recent cell-associated HCMV isolates, then removed and transferred to various recipient cell cultures. The transfer efficiency in the recipient cultures was evaluated by immunofluorescence staining of viral immediate early antigens. Soluble derivatives of the cellular HCMV entry receptor PDGFRα were analyzed for their potential to interfere with this transfer. All of five tested HCMV isolates could be transferred to fibroblasts, endothelial and epithelial cells with transfer rates ranging from 2 to 9%, and the transferred viruses could spread focally in these recipient cells within 1 week. The PDGFRα-derived peptides IK40 and GT40 reduced transfer by 40 and 70% when added during the uptake step. However, when added during the transfer step, only IK40 was effective, inhibiting transmission by 20% on endothelial cells and 50–60% on epithelial cells and fibroblasts. These findings further corroborate the assumption of cell-associated HCMV dissemination by PMNs and demonstrate that it is possible to inhibit this transmission mode.
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Affiliation(s)
- Berenike Braun
- Institute for Virology, Ulm University Medical Center, Ulm, Germany.
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9
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Weiler N, Paal C, Adams K, Calcaterra C, Fischer D, Stanton RJ, Stöhr D, Laib Sampaio K, Sinzger C. Role of Envelope Glycoprotein Complexes in Cell-Associated Spread of Human Cytomegalovirus. Viruses 2021; 13:v13040614. [PMID: 33918406 PMCID: PMC8066785 DOI: 10.3390/v13040614] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 03/26/2021] [Indexed: 12/15/2022] Open
Abstract
The role of viral envelope glycoproteins, particularly the accessory proteins of trimeric and pentameric gH/gL-complexes, in cell-associated spread of human cytomegalovirus (HCMV) is unclear. We aimed to investigate their contribution in the context of HCMV variants that grow in a strictly cell-associated manner. In the genome of Merlin pAL1502, the glycoproteins gB, gH, gL, gM, and gN were deleted by introducing stop codons, and the mutants were analyzed for viral growth. Merlin and recent HCMV isolates were compared by quantitative immunoblotting for expression of accessory proteins of the trimeric and pentameric gH/gL-complexes, gO and pUL128. Isolates were treated with siRNAs against gO and pUL128 and analyzed regarding focal growth and release of infectious virus. All five tested glycoproteins were essential for growth of Merlin pAL1502. Compared with this model virus, higher gO levels were measured in recent isolates of HCMV, and its knockdown decreased viral growth. Knockdown of pUL128 abrogated the strict cell-association and led to release of infectivity, which allowed cell-free transfer to epithelial cells where the virus grew again strictly cell-associated. We conclude that both trimer and pentamer contribute to cell-associated spread of recent clinical HCMV isolates and downregulation of pentamer can release infectious virus into the supernatant.
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Affiliation(s)
- Nina Weiler
- Institute for Virology, Ulm University Medical Center, 89089 Ulm, Germany; (N.W.); (C.P.); (K.A.); (C.C.); (D.F.); (D.S.); (K.L.S.)
| | - Caroline Paal
- Institute for Virology, Ulm University Medical Center, 89089 Ulm, Germany; (N.W.); (C.P.); (K.A.); (C.C.); (D.F.); (D.S.); (K.L.S.)
| | - Kerstin Adams
- Institute for Virology, Ulm University Medical Center, 89089 Ulm, Germany; (N.W.); (C.P.); (K.A.); (C.C.); (D.F.); (D.S.); (K.L.S.)
| | - Christopher Calcaterra
- Institute for Virology, Ulm University Medical Center, 89089 Ulm, Germany; (N.W.); (C.P.); (K.A.); (C.C.); (D.F.); (D.S.); (K.L.S.)
| | - Dina Fischer
- Institute for Virology, Ulm University Medical Center, 89089 Ulm, Germany; (N.W.); (C.P.); (K.A.); (C.C.); (D.F.); (D.S.); (K.L.S.)
| | - Richard James Stanton
- Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff CF14 4XN, UK;
| | - Dagmar Stöhr
- Institute for Virology, Ulm University Medical Center, 89089 Ulm, Germany; (N.W.); (C.P.); (K.A.); (C.C.); (D.F.); (D.S.); (K.L.S.)
| | - Kerstin Laib Sampaio
- Institute for Virology, Ulm University Medical Center, 89089 Ulm, Germany; (N.W.); (C.P.); (K.A.); (C.C.); (D.F.); (D.S.); (K.L.S.)
| | - Christian Sinzger
- Institute for Virology, Ulm University Medical Center, 89089 Ulm, Germany; (N.W.); (C.P.); (K.A.); (C.C.); (D.F.); (D.S.); (K.L.S.)
- Correspondence:
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10
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Choi KY, El-Hamdi NS, McGregor A. A trimeric capable gB CMV vaccine provides limited protection against a highly cell associated and epithelial tropic strain of cytomegalovirus in guinea pigs. J Gen Virol 2021; 102. [PMID: 33729125 DOI: 10.1099/jgv.0.001579] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Multiple strains of human cytomegalovirus (HCMV) can cause congenital cytomegalovirus (cCMV) by primary or secondary infection. The viral gB glycoprotein is a leading vaccine candidate, essential for infection of all cell-types, and immunodominant antibody target. Guinea pig cytomegalovirus (GPCMV) is the only small animal model for cCMV. Various gB vaccines have shown efficacy but studies have utilized truncated gB and protection against prototype strain 22122 with preferential tropism to fibroblasts despite encoding a gH-based pentamer complex for non-fibroblast infection. A highly cell-associated novel strain of GPCMV (TAMYC) with 99 % identity in gB sequence to 22122 exhibited preferred tropism to epithelial cells. An adenovirus vaccine encoding full-length gB (AdgB) was highly immunogenic and partially protected against 22122 strain challenge in vaccinated animals but not when challenged with TAMYC strain. GPCMV studies with AdgB vaccine sera on numerous cell-types demonstrated impaired neutralization (NA50) compared to fibroblasts. GPCMV-convalescent sera including pentamer complex antibodies increased virus neutralization on non-fibroblasts and anti-gB depletion from GPCMV-convalescent sera had minimal impact on epithelial cell neutralization. GPCMV(PC+) 22122-convalescent animals challenged with TAMYC exhibited higher protection compared to AdgB vaccine. Overall, results suggest that antibody response to both gB and PC are important components of a GPCMV vaccine.
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Affiliation(s)
- K Yeon Choi
- Dept. Microbial Pathogenesis & Immunology, College of Medicine, Texas A&M University, Bryan, TX, USA
| | - Nadia S El-Hamdi
- Dept. Microbial Pathogenesis & Immunology, College of Medicine, Texas A&M University, Bryan, TX, USA
| | - Alistair McGregor
- Dept. Microbial Pathogenesis & Immunology, College of Medicine, Texas A&M University, Bryan, TX, USA
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Kolb P, Hoffmann K, Sievert A, Reinhard H, Merce-Maldonado E, Le-Trilling VTK, Halenius A, Gütle D, Hengel H. Human cytomegalovirus antagonizes activation of Fcγ receptors by distinct and synergizing modes of IgG manipulation. eLife 2021; 10:63877. [PMID: 33724188 PMCID: PMC8041466 DOI: 10.7554/elife.63877] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 03/15/2021] [Indexed: 01/19/2023] Open
Abstract
Human cytomegalovirus (HCMV) is endowed with multiple highly sophisticated immune evasion strategies. This includes the evasion from antibody mediated immune control by counteracting host Fc-gamma receptor (FcγR) mediated immune control mechanisms such as antibody-dependent cellular cytotoxicity (ADCC). We have previously shown that HCMV avoids FcγR activation by concomitant expression of the viral Fc-gamma-binding glycoproteins (vFcγRs) gp34 and gp68. We now show that gp34 and gp68 bind IgG simultaneously at topologically different Fcγ sites and achieve efficient antagonization of host FcγR activation by distinct but synergizing mechanisms. While gp34 enhances immune complex internalization, gp68 acts as inhibitor of host FcγR binding to immune complexes. In doing so, gp68 induces Fcγ accessibility to gp34 and simultaneously limits host FcγR recognition. The synergy of gp34 and gp68 is compelled by the interfering influence of excessive non-immune IgG ligands and highlights conformational changes within the IgG globular chains critical for antibody effector function. Human cytomegalovirus is a type of herpes virus that rarely causes symptoms in healthy people but can cause serious complications in unborn babies and in people with compromised immune systems, such as transplant recipients. The virus has found ways to successfully evade the immune system, and once infected, the body retains the virus for life. It deploys an arsenal of proteins that bind to antibodies, specialized proteins the immune system uses to flag virus-infected cells for destruction. This prevents certain cells of the immune system, the natural killer cells, from recognizing and destroying virus-infected cells. These immune-evading proteins are called viral Fc-gamma receptors, or vFcγRs. While it has been previously shown that these receptors are able to evade the immune system, it remained unknown how exactly they prevent natural killer cells from recognizing infected cells. Now, Kolb et al. show that the cytomegalovirus deploys two vFcγRs called gp34 and gp68, which work together to block natural killer cells. The latter reduces the ability of natural killer cells to bind to antibodies on cytomegalovirus-infected cells. This paves the way for gp34 to pull virus proteins from the surface of the infected cell, making them inaccessible to the immune system. Neither protein fully protects virus-infected cells on its own, but together they are highly effective. The experiments reveal further details about how cytomegalovirus uses two defense mechanisms simultaneously to outmaneuver the immune system. Understanding this two-part viral evasion system may help scientists to develop vaccines or new treatments that can protect vulnerable people from diseases caused by the cytomegalovirus.
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Affiliation(s)
- Philipp Kolb
- Faculty of Medicine, Albert-Ludwigs-University Freiburg, Freiburg, Germany.,Institute of Virology, University Medical Center, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Katja Hoffmann
- Faculty of Medicine, Albert-Ludwigs-University Freiburg, Freiburg, Germany.,Institute of Virology, University Medical Center, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Annika Sievert
- Faculty of Medicine, Albert-Ludwigs-University Freiburg, Freiburg, Germany.,Institute of Virology, University Medical Center, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Henrike Reinhard
- Institute of Virology, University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Eva Merce-Maldonado
- Institute of Virology, University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | | | - Anne Halenius
- Faculty of Medicine, Albert-Ludwigs-University Freiburg, Freiburg, Germany.,Institute of Virology, University Medical Center, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Dominique Gütle
- Faculty of Medicine, Albert-Ludwigs-University Freiburg, Freiburg, Germany.,Institute of Virology, University Medical Center, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Hartmut Hengel
- Faculty of Medicine, Albert-Ludwigs-University Freiburg, Freiburg, Germany.,Institute of Virology, University Medical Center, Albert-Ludwigs-University Freiburg, Freiburg, Germany
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12
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Metagenomic analysis and identification of emerging pathogens in blood from healthy donors. Sci Rep 2020; 10:15809. [PMID: 32978450 PMCID: PMC7519034 DOI: 10.1038/s41598-020-72808-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 09/07/2020] [Indexed: 11/23/2022] Open
Abstract
Emerging infectious pathogens that threaten blood transfusions are known to be present in blood samples from healthy/qualified donors. The objective of this study was to investigate the microbiome of blood from healthy donors from the Luzhou area in southwestern China. Potential pathogens and cytomegalovirus (CMV) infection in the donor blood were identified. Total plasma nucleic acids were extracted from one pool of 5734 samples and were constructed for metagenomics analysis using Illumina sequencing. The microbiome and potential emerging/re-emerging pathogens were identified using bioinformatics analysis. Moreover, CMV antigen was measured via an enzyme-linked immunosorbent assay, and the CMV DNA level was assessed by quantitative RT-PCR. A total of 132 bacterial reads, 65 viral reads and 165 parasitic reads were obtained. The most frequent bacterium was Escherichia coli (95/132, 72%) with 95 reads in 132 bacterial reads, and the most prevalent parasite was Toxoplasma gondii (131/165, 79%). Among the viruses, cytomegalovirus (44/65, 68%) accounted for the highest frequency, followed by Hepatitis E Virus (10/65, 15%). Moreover, the positive rate of CMV-IgG was 46.25% (2652/5734), and the positive rate of CMV-IgM was 5.82% (334/5734). The positive rate of dual positive (IgG+ and IgM+) CMV was 0.07% (4/5734). Twenty-one (0.37%) specimens from 5734 donated blood samples were positive for CMV DNA. The CMV DNA levels ranged from 7.56 × 102 to 3.58 × 103 copies/mL. The current study elucidated the microbiome structure in blood from healthy/qualified donors in the Luzhou area and identified emerging/re-emerging pathogens. This preliminary study contributes to information regarding blood transfusion safety in China.
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Theobald SJ, Kreer C, Khailaie S, Bonifacius A, Eiz-Vesper B, Figueiredo C, Mach M, Backovic M, Ballmaier M, Koenig J, Olbrich H, Schneider A, Volk V, Danisch S, Gieselmann L, Ercanoglu MS, Messerle M, von Kaisenberg C, Witte T, Klawonn F, Meyer-Hermann M, Klein F, Stripecke R. Repertoire characterization and validation of gB-specific human IgGs directly cloned from humanized mice vaccinated with dendritic cells and protected against HCMV. PLoS Pathog 2020; 16:e1008560. [PMID: 32667948 PMCID: PMC7363084 DOI: 10.1371/journal.ppat.1008560] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 04/18/2020] [Indexed: 12/16/2022] Open
Abstract
Human cytomegalovirus (HCMV) causes serious complications to immune compromised hosts. Dendritic cells (iDCgB) expressing granulocyte-macrophage colony-stimulating factor, interferon-alpha and HCMV-gB were developed to promote de novo antiviral adaptive responses. Mice reconstituted with a human immune system (HIS) were immunized with iDCgB and challenged with HCMV, resulting into 93% protection. Immunization stimulated the expansion of functional effector memory CD8+ and CD4+ T cells recognizing gB. Machine learning analyses confirmed bone marrow T/CD4+, liver B/IgA+ and spleen B/IgG+ cells as predictive biomarkers of immunization (≈87% accuracy). CD8+ and CD4+ T cell responses against gB were validated. Splenic gB-binding IgM-/IgG+ B cells were sorted and analyzed at a single cell level. iDCgB immunizations elicited human-like IgG responses with a broad usage of various IgG heavy chain V gene segments harboring variable levels of somatic hypermutation. From this search, two gB-binding human monoclonal IgGs were generated that neutralized HCMV infection in vitro. Passive immunization with these antibodies provided proof-of-concept evidence of protection against HCMV infection. This HIS/HCMV in vivo model system supported the validation of novel active and passive immune therapies for future clinical translation. Human cytomegalovirus (HCMV) is a ubiquitous pathogen. As long as the immune system is functional, T and B cells can control HCMV. Yet, for patients who have debilitated immune functions, HCMV infections and reactivations cause major complications. Vaccines or antibodies to prevent or treat HCMV are not yet approved. Novel animal models for testing new immunization approaches are emerging and are important tools to identify biomedical products with a reasonable chance to work in patients. Here, we used a model based on mice transplanted with human immune cells and infected with a traceable HCMV. We tested a cell vaccine (iDCgB) carrying gB, a potent HCMV antigen. The model showed that iDCgB halted the HCMV infection in more than 90% of the mice. We found that antibodies were key players mediating protection. Using state-of-the-art methods, we were able to use the sequences of the human antibodies generated in the mice to construct and produce monoclonal antibodies in the laboratory. Proof-of-concept experiments indicated that administration of these monoclonal antibodies into mice protected them against HCMV infection. In summary, this humanized mouse model was useful to test a vaccine and to generate and test novel antibodies that can be further developed for human use.
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Affiliation(s)
- Sebastian J. Theobald
- Clinic of Hematology, Hemostasis, Oncology and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany
- Laboratory of Regenerative Immune Therapies Applied, Excellence Cluster REBIRTH, Hannover Medical School, Hannover, Germany
- German Centre for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Hannover, Germany
| | - Christoph Kreer
- Laboratory of Experimental Immunology, Institute of Virology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University Hospital of Cologne, Cologne, Germany
| | - Sahamoddin Khailaie
- Department of Systems Immunology and Braunschweig Integrated Centre of Systems Biology (BRICS), Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Agnes Bonifacius
- Institute of Transfusion Medicine and Transplant Engineering, Hannover Medical School, Hannover, Germany
| | - Britta Eiz-Vesper
- Institute of Transfusion Medicine and Transplant Engineering, Hannover Medical School, Hannover, Germany
| | - Constanca Figueiredo
- Institute of Transfusion Medicine and Transplant Engineering, Hannover Medical School, Hannover, Germany
| | - Michael Mach
- Institute of Virology, University Erlangen-Nürnberg, Erlangen, Germany
| | - Marija Backovic
- Structural Virology Unit, Department of Virology, Institut Pasteur, Paris, France; CNRS UMR 3569, Paris, France
| | - Matthias Ballmaier
- Research Facility Cell Sorting, Hannover Medical School, Hannover, Germany
| | - Johannes Koenig
- Clinic of Hematology, Hemostasis, Oncology and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany
- Laboratory of Regenerative Immune Therapies Applied, Excellence Cluster REBIRTH, Hannover Medical School, Hannover, Germany
- German Centre for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Hannover, Germany
| | - Henning Olbrich
- Clinic of Hematology, Hemostasis, Oncology and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany
- Laboratory of Regenerative Immune Therapies Applied, Excellence Cluster REBIRTH, Hannover Medical School, Hannover, Germany
- German Centre for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Hannover, Germany
| | - Andreas Schneider
- Clinic of Hematology, Hemostasis, Oncology and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany
- Laboratory of Regenerative Immune Therapies Applied, Excellence Cluster REBIRTH, Hannover Medical School, Hannover, Germany
- German Centre for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Hannover, Germany
| | - Valery Volk
- Clinic of Hematology, Hemostasis, Oncology and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany
- Laboratory of Regenerative Immune Therapies Applied, Excellence Cluster REBIRTH, Hannover Medical School, Hannover, Germany
- German Centre for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Hannover, Germany
| | - Simon Danisch
- Clinic of Hematology, Hemostasis, Oncology and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany
- Laboratory of Regenerative Immune Therapies Applied, Excellence Cluster REBIRTH, Hannover Medical School, Hannover, Germany
- German Centre for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Hannover, Germany
| | - Lutz Gieselmann
- Laboratory of Experimental Immunology, Institute of Virology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University Hospital of Cologne, Cologne, Germany
- German Centre for Infection Research, Partner Site Bonn-Cologne, Cologne, Germany
| | - Meryem Seda Ercanoglu
- Laboratory of Experimental Immunology, Institute of Virology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University Hospital of Cologne, Cologne, Germany
| | - Martin Messerle
- German Centre for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Hannover, Germany
- Instiute of Virology, Hannover Medical School, Hannover, Germany
| | - Constantin von Kaisenberg
- Department of Obstetrics, Clinic of Gynecology and Reproductive Medicine, and Obstetrics, Hannover Medical School, Hannover, Germany
| | - Torsten Witte
- Department of Rheumatology and Immunology, Hannover Medical School, Hannover, Germany
| | - Frank Klawonn
- Biostatistics Group, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Institute for Information Engineering, Ostfalia University, Wolfenbuettel, Germany
| | - Michael Meyer-Hermann
- Department of Systems Immunology and Braunschweig Integrated Centre of Systems Biology (BRICS), Helmholtz Centre for Infection Research, Braunschweig, Germany
- Institute for Biochemistry, Biotechnology and Bioinformatics, Technische Universität Braunschweig, Braunschweig, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
| | - Florian Klein
- Laboratory of Experimental Immunology, Institute of Virology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University Hospital of Cologne, Cologne, Germany
- German Centre for Infection Research, Partner Site Bonn-Cologne, Cologne, Germany
| | - Renata Stripecke
- Clinic of Hematology, Hemostasis, Oncology and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany
- Laboratory of Regenerative Immune Therapies Applied, Excellence Cluster REBIRTH, Hannover Medical School, Hannover, Germany
- German Centre for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Hannover, Germany
- * E-mail:
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