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Früh SP, Adu OF, López-Astacio RA, Weichert WS, Wasik BR, Parrish CR. Isolation, cloning and analysis of parvovirus-specific canine antibodies from peripheral blood B cells. Dev Comp Immunol 2023; 147:104894. [PMID: 37467826 PMCID: PMC10542859 DOI: 10.1016/j.dci.2023.104894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 07/05/2023] [Accepted: 07/16/2023] [Indexed: 07/21/2023]
Abstract
B-cell cloning methods enable the analysis of antibody responses against target antigens and can be used to reveal the host antibody repertoire, antigenic sites (epitopes), and details of protective immunity against pathogens. Here, we describe improved methods for isolation of canine peripheral blood B cells producing antibodies against canine parvovirus (CPV) capsids by fluorescence-activated cell sorting, followed by cell cloning. We cultured sorted B cells from an immunized dog in vitro and screened for CPV-specific antibody production. Updated canine-specific primer sets were used to amplify and clone the heavy and light chain immunoglobulin sequences directly from the B cells by reverse transcription and PCR. Monoclonal canine IgGs were produced by cloning heavy and light chain sequences into antibody expression vectors, which were screened for CPV binding. Three different canine monoclonal antibodies were analyzed, including two that shared the same heavy chain, and one that had distinct heavy and light chains. The antibodies showed broad binding to CPV variants, and epitopes were mapped to antigenic sites on the capsid. The methods described here are applicable for the isolation of canine B cells and monoclonal antibodies against many antigens.
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Affiliation(s)
- Simon P Früh
- Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA; Department of Veterinary Sciences, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Oluwafemi F Adu
- Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Robert A López-Astacio
- Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Wendy S Weichert
- Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Brian R Wasik
- Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Colin R Parrish
- Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA.
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Hartmann SR, Charnesky AJ, Früh SP, López-Astacio RA, Weichert WS, DiNunno N, Cho SH, Bator CM, Parrish CR, Hafenstein SL. Cryo EM structures map a post vaccination polyclonal antibody response to canine parvovirus. Commun Biol 2023; 6:955. [PMID: 37726539 PMCID: PMC10509169 DOI: 10.1038/s42003-023-05319-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 09/04/2023] [Indexed: 09/21/2023] Open
Abstract
Canine parvovirus (CPV) is an important pathogen that emerged by cross-species transmission to cause severe disease in dogs. To understand the host immune response to vaccination, sera from dogs immunized with parvovirus are obtained, the polyclonal antibodies are purified and used to solve the high resolution cryo EM structures of the polyclonal Fab-virus complexes. We use a custom software, Icosahedral Subparticle Extraction and Correlated Classification (ISECC) to perform subparticle analysis and reconstruct polyclonal Fab-virus complexes from two different dogs eight and twelve weeks post vaccination. In the resulting polyclonal Fab-virus complexes there are a total of five distinct Fabs identified. In both cases, any of the five antibodies identified would interfere with receptor binding. This polyclonal mapping approach identifies a specific, limited immune response to the live vaccine virus and allows us to investigate the binding of multiple different antibodies or ligands to virus capsids.
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Affiliation(s)
- Samantha R Hartmann
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Andrew J Charnesky
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Simon P Früh
- Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Robert A López-Astacio
- Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Wendy S Weichert
- Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Nadia DiNunno
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Sung Hung Cho
- Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Carol M Bator
- Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Colin R Parrish
- Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Susan L Hafenstein
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA.
- Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA.
- Department of Medicine, The Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA.
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López-Astacio RA, Adu OF, Lee H, Hafenstein SL, Parrish CR. The Structures and Functions of Parvovirus Capsids and Missing Pieces: the Viral DNA and Its Packaging, Asymmetrical Features, Nonprotein Components, and Receptor or Antibody Binding and Interactions. J Virol 2023; 97:e0016123. [PMID: 37367301 PMCID: PMC10373561 DOI: 10.1128/jvi.00161-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2023] Open
Abstract
Parvoviruses are among the smallest and superficially simplest animal viruses, infecting a broad range of hosts, including humans, and causing some deadly infections. In 1990, the first atomic structure of the canine parvovirus (CPV) capsid revealed a 26-nm-diameter T=1 particle made up of two or three versions of a single protein, and packaging about 5,100 nucleotides of single-stranded DNA. Our structural and functional understanding of parvovirus capsids and their ligands has increased as imaging and molecular techniques have advanced, and capsid structures for most groups within the Parvoviridae family have now been determined. Despite those advances, significant questions remain unanswered about the functioning of those viral capsids and their roles in release, transmission, or cellular infection. In addition, the interactions of capsids with host receptors, antibodies, or other biological components are also still incompletely understood. The parvovirus capsid's apparent simplicity likely conceals important functions carried out by small, transient, or asymmetric structures. Here, we highlight some remaining open questions that may need to be answered to provide a more thorough understanding of how these viruses carry out their various functions. The many different members of the family Parvoviridae share a capsid architecture, and while many functions are likely similar, others may differ in detail. Many of those parvoviruses have not been experimentally examined in detail (or at all in some cases), so we, therefore, focus this minireview on the widely studied protoparvoviruses, as well as the most thoroughly investigated examples of adeno-associated viruses.
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Affiliation(s)
- Robert A. López-Astacio
- Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Oluwafemi F. Adu
- Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Hyunwook Lee
- Department of Biochemistry and Molecular Biology, Penn State University, University Park, Pennsylvania, USA
| | - Susan L. Hafenstein
- Department of Biochemistry and Molecular Biology, Penn State University, University Park, Pennsylvania, USA
| | - Colin R. Parrish
- Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
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López-Astacio RA, Adu OF, Goetschius DJ, Lee H, Weichert WS, Wasik BR, Frueh SP, Alford BK, Voorhees IEH, Flint JF, Saddoris S, Goodman LB, Holmes EC, Hafenstein SL, Parrish CR. Viral Capsid, Antibody, and Receptor Interactions: Experimental Analysis of the Antibody Escape Evolution of Canine Parvovirus. J Virol 2023; 97:e0009023. [PMID: 37199627 PMCID: PMC10308881 DOI: 10.1128/jvi.00090-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 04/23/2023] [Indexed: 05/19/2023] Open
Abstract
Canine parvovirus (CPV) is a small nonenveloped single-stranded DNA virus that causes serious diseases in dogs worldwide. The original strain of the virus (CPV-2) emerged in dogs during the late 1970s due to a host range switch of a virus similar to the feline panleukopenia virus that infected another host. The virus that emerged in dogs had altered capsid receptor and antibody binding sites, with some changes affecting both functions. Further receptor and antibody binding changes arose when the virus became better adapted to dogs or to other hosts. Here, we used in vitro selection and deep sequencing to reveal how two antibodies with known interactions select for escape mutations in CPV. The antibodies bound two distinct epitopes, and one largely overlapped the host receptor binding site. We also generated mutated antibody variants with altered binding structures. Viruses were passaged with wild-type (WT) or mutated antibodies, and their genomes were deep sequenced during the selective process. A small number of mutations were detected only within the capsid protein gene during the first few passages of selection, and most sites remained polymorphic or were slow to go to fixation. Mutations arose both within and outside the antibody binding footprints on the capsids, and all avoided the transferrin receptor type 1 binding footprint. Many selected mutations matched those that have arisen in the natural evolution of the virus. The patterns observed reveal the mechanisms by which these variants have been selected in nature and provide a better understanding of the interactions between antibody and receptor selections. IMPORTANCE Antibodies protect animals against infection by many different viruses and other pathogens, and we are gaining new information about the epitopes that induce antibody responses against viruses and the structures of the bound antibodies. However, less is known about the processes of antibody selection and antigenic escape and the constraints that apply in this system. Here, we used an in vitro model system and deep genome sequencing to reveal the mutations that arose in the virus genome during selection by each of two monoclonal antibodies or their mutated variants. High-resolution structures of each of the Fab:capsid complexes revealed their binding interactions. The wild-type antibodies or their mutated variants allowed us to examine how changes in antibody structure influence the mutational selection patterns seen in the virus. The results shed light on the processes of antibody binding, neutralization escape, and receptor binding, and they likely have parallels for many other viruses.
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Affiliation(s)
- Robert A. López-Astacio
- James A. Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Oluwafemi F. Adu
- James A. Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Daniel J. Goetschius
- Department of Biochemistry and Molecular Biology, Penn State University, University Park, Pennsylvania, USA
| | - Hyunwook Lee
- Department of Biochemistry and Molecular Biology, Penn State University, University Park, Pennsylvania, USA
| | - Wendy S. Weichert
- James A. Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Brian R. Wasik
- James A. Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Simon P. Frueh
- James A. Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
- Department for Veterinary Sciences, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Brynn K. Alford
- James A. Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Ian E. H. Voorhees
- James A. Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Joseph F. Flint
- James A. Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Sarah Saddoris
- James A. Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Laura B. Goodman
- James A. Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Edward C. Holmes
- Sydney Institute for Infectious Diseases, School of Medical Sciences, University of Sydney, Sydney, New South Wales, Australia
| | - Susan L. Hafenstein
- Department of Biochemistry and Molecular Biology, Penn State University, University Park, Pennsylvania, USA
| | - Colin R. Parrish
- James A. Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
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López-Astacio RA, Adu OF, Goetschius DJ, Lee H, Weichert WS, Wasik BR, Frueh SP, Alford BK, Voorhees IE, Flint JF, Saddoris S, Goodman LB, Holmes EC, Hafenstein SL, Parrish CR. Viral capsid, antibody, and receptor interactions: experimental analysis of the antibody escape evolution of canine parvovirus. bioRxiv 2023:2023.01.18.524668. [PMID: 36711712 PMCID: PMC9882321 DOI: 10.1101/2023.01.18.524668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Canine parvovirus (CPV) is a small non-enveloped single-stranded DNA virus that causes serious diseases in dogs worldwide. The original strain of the virus (CPV-2) emerged in dogs during the late-1970s due to a host range switch of a virus similar to the feline panleukopenia virus (FPV) that infected another host. The virus that emerged in dogs had altered capsid receptor- and antibody-binding sites, with some changes affecting both functions. Further receptor and antibody binding changes arose when the virus became better adapted to dogs or to other hosts. Here, we use in vitro selection and deep sequencing to reveal how two antibodies with known interactions select for escape mutations in CPV. The antibodies bind two distinct epitopes, and one largely overlaps the host receptor binding site. We also engineered antibody variants with altered binding structures. Viruses were passaged with the wild type or mutated antibodies, and their genomes deep sequenced during the selective process. A small number of mutations were detected only within the capsid protein gene during the first few passages of selection, and most sites remained polymorphic or were slow to go to fixation. Mutations arose both within and outside the antibody binding footprints on the capsids, and all avoided the TfR-binding footprint. Many selected mutations matched those that have arisen in the natural evolution of the virus. The patterns observed reveal the mechanisms by which these variants have been selected in nature and provide a better understanding of the interactions between antibody and receptor selections. IMPORTANCE Antibodies protect animals against infection by many different viruses and other pathogens, and we are gaining new information about the epitopes that induce antibody responses against viruses and the structures of the bound antibodies. However, less is known about the processes of antibody selection and antigenic escape and the constraints that apply in this system. Here, we use an in vitro model system and deep genome sequencing to reveal the mutations that arise in the virus genome during selection by each of two monoclonal antibodies or their engineered variants. High-resolution structures of each of the Fab: capsid complexes revealed their binding interactions. The engineered forms of the wild-type antibodies or mutant forms allowed us to examine how changes in antibody structure influence the mutational selection patterns seen in the virus. The results shed light on the processes of antibody binding, neutralization escape, and receptor binding, and likely have parallels for many other viruses.
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