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Hoffmann MD, Sorensen RJ, Extross A, He Y, Schmidt D. Protein Carrier AAV. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.14.607995. [PMID: 39185209 PMCID: PMC11343202 DOI: 10.1101/2024.08.14.607995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/27/2024]
Abstract
AAV is widely used for efficient delivery of DNA payloads. The extent to which the AAV capsid can be used to deliver a protein payload is unexplored. Here, we report engineered AAV capsids that directly package proteins - Protein Carrier AAV (pcAAV). Nanobodies inserted into the interior of the capsid mediate packaging of a cognate protein, including Green Fluorescent Protein (GFP), Streptococcus pyogenes Cas9, Cre recombinase, and the engineered peroxidase APEX2. We show that protein packaging efficiency is affected by the nanobody insertion position, the capsid protein isoform into which the nanobody is inserted, and the subcellular localization of the packaged protein during recombinant AAV capsid production; each of these factors can be rationally engineered to optimize protein packaging efficiency. We demonstrate that proteins packaged within pcAAV retain their enzymatic activity and that pcAAV can bind and enter the cell to deliver the protein payload. Establishing pcAAV as a protein delivery platform may expand the utility of AAV as a therapeutic and research tool.
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2
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Smiley AT, Babilonia-Díaz N, Krueger AJ, Aihara H, Tompkins KJ, Lemmex ACD, Gordon WR. Sequence-Directed Covalent Protein-RNA Linkages in a Single Step Using Engineered HUH-Tags. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.13.607811. [PMID: 39185166 PMCID: PMC11343116 DOI: 10.1101/2024.08.13.607811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/27/2024]
Abstract
Replication-initiating HUH-endonucleases (Reps) are enzymes that form covalent bonds with single-stranded DNA (ssDNA) in a sequence specific manner to initiate rolling circle replication. These nucleases have been co-opted for use in biotechnology as sequence specific protein-ssDNA bioconjugation fusion partners dubbed 'HUH-tags'. Here, we describe the engineering and in vitro characterization of a series of laboratory evolved HUH-tags capable of forming robust sequence-directed covalent bonds with unmodified RNA substrates. We show that promiscuous Rep-RNA interaction can be enhanced through directed evolution from nearly undetectable levels in wildtype enzymes to robust reactivity in final engineered iterations. Taken together, these engineered HUH-tags represent a promising platform for enabling site-specific protein-RNA covalent bioconjugation in vitro, potentially mediating a host of new applications and offering a valuable addition to the HUH-tag repertoire.
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Affiliation(s)
- Adam T Smiley
- University of Minnesota, Department of Biochemistry, Molecular Biology, and Biophysics
| | | | - August J Krueger
- University of Minnesota, Department of Biochemistry, Molecular Biology, and Biophysics
| | - Hideki Aihara
- University of Minnesota, Department of Biochemistry, Molecular Biology, and Biophysics
| | - Kassidy J Tompkins
- University of Minnesota, Department of Biochemistry, Molecular Biology, and Biophysics
| | - Andrew C D Lemmex
- University of Minnesota, Department of Biochemistry, Molecular Biology, and Biophysics
| | - Wendy R Gordon
- University of Minnesota, Department of Biochemistry, Molecular Biology, and Biophysics
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3
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Zhou X, Liu J, Xiao S, Liang X, Li Y, Mo F, Xin X, Yang Y, Gao C. Adeno-Associated Virus Engineering and Load Strategy for Tropism Modification, Immune Evasion and Enhanced Transgene Expression. Int J Nanomedicine 2024; 19:7691-7708. [PMID: 39099791 PMCID: PMC11296317 DOI: 10.2147/ijn.s459905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 06/21/2024] [Indexed: 08/06/2024] Open
Abstract
Gene therapy aims to add, replace or turn off genes to help treat disease. To date, the US Food and Drug Administration (FDA) has approved 14 gene therapy products. With the increasing interest in gene therapy, feasible gene delivery vectors are necessary for inserting new genes into cells. There are different kinds of gene delivery vectors including viral vectors like lentivirus, adenovirus, retrovirus, adeno-associated virus et al, and non-viral vectors like naked DNA, lipid vectors, polymer nanoparticles, exosomes et al, with viruses being the most commonly used. Among them, the most concerned vector is adeno-associated virus (AAV) because of its safety, natural ability to efficiently deliver gene into cells and sustained transgene expression in multiple tissues. In addition, the AAV genome can be engineered to generate recombinant AAV (rAAV) containing transgene sequences of interest and has been proven to be a safe gene vector. Recently, rAAV vectors have been approved for the treatment of various rare diseases. Despite these approvals, some major limitations of rAAV remain, namely nonspecific tissue targeting and host immune response. Additional problems include neutralizing antibodies that block transgene delivery, a finite transgene packaging capacity, high viral titer used for per dose and high cost. To deal with these challenges, several techniques have been developed. Based on differences in engineering methods, this review proposes three strategies: gene engineering-based capsid modification (capsid modification), capsid surface tethering through chemical conjugation (surface tethering), and other formulations loaded with AAV (virus load). In addition, the major advantages and limitations encountered in rAAV engineering strategies are summarized.
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Affiliation(s)
- Xun Zhou
- School of Pharmacy, Henan University, Kaifeng, People’s Republic of China
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, People’s Republic of China
| | - Jingzhou Liu
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, People’s Republic of China
| | - Shuang Xiao
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, People’s Republic of China
- School of Pharmacy, Guangxi Medical University, Nanning, People’s Republic of China
| | - Xiaoqing Liang
- School of Pharmacy, Henan University, Kaifeng, People’s Republic of China
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, People’s Republic of China
| | - Yi Li
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, People’s Republic of China
| | - Fengzhen Mo
- School of Pharmacy, Guangxi Medical University, Nanning, People’s Republic of China
| | - Xin Xin
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, People’s Republic of China
| | - Yang Yang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, People’s Republic of China
| | - Chunsheng Gao
- School of Pharmacy, Henan University, Kaifeng, People’s Republic of China
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, People’s Republic of China
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4
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Pham Q, Glicksman J, Chatterjee A. Chemical approaches to probe and engineer AAV vectors. NANOSCALE 2024; 16:13820-13833. [PMID: 38978480 PMCID: PMC11271820 DOI: 10.1039/d4nr01300j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Accepted: 06/14/2024] [Indexed: 07/10/2024]
Abstract
Adeno-associated virus (AAV) has emerged as the most promising vector for in vivo human gene therapy, with several therapeutic approvals in the last few years and countless more under development. Underlying this remarkable success are several attractive features that AAV offers, including lack of pathogenicity, low immunogenicity, long-term gene expression without genomic integration, the ability to infect both dividing and non-dividing cells, etc. However, the commonly used wild-type AAV capsids in therapeutic development present significant challenges, including inadequate tissue specificity and the need for large doses to attain therapeutic effectiveness, raising safety concerns. Additionally, significant preexisting adaptive immunity against most natural capsids, and the development of such anti-capsid immunity after the first treatment, represent major challenges. Strategies to engineer the AAV capsid are critically needed to address these challenges and unlock the full promise of AAV gene therapy. Chemical modification of the AAV capsid has recently emerged as a powerful new approach to engineer its properties. Unlike genetic strategies, which can be more disruptive to the delicate capsid assembly and packaging processes, "late-stage" chemical modification of the assembled capsid-whether at natural amino acid residues or site-specifically installed noncanonical amino acid residues-often enables a versatile approach to introducing new properties to the capsid. This review summarizes the significant recent progress in AAV capsid engineering strategies, with a particular focus on chemical modifications in advancing the next generation of AAV-based gene therapies.
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Affiliation(s)
- Quan Pham
- Department of Chemistry, Boston College, 2609 Beacon Street, Chestnut Hill, MA 02467, USA.
| | - Jake Glicksman
- Department of Chemistry, Boston College, 2609 Beacon Street, Chestnut Hill, MA 02467, USA.
| | - Abhishek Chatterjee
- Department of Chemistry, Boston College, 2609 Beacon Street, Chestnut Hill, MA 02467, USA.
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Hoffmann M, Gallant J, LeBeau A, Schmidt D. Unlocking precision gene therapy: harnessing AAV tropism with nanobody swapping at capsid hotspots. NAR MOLECULAR MEDICINE 2024; 1:ugae008. [PMID: 39022346 PMCID: PMC11250487 DOI: 10.1093/narmme/ugae008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 07/01/2024] [Accepted: 07/03/2024] [Indexed: 07/20/2024]
Abstract
Adeno-associated virus (AAV) has been remarkably successful in the clinic, but its broad tropism is a practical limitation of precision gene therapy. A promising path to engineer AAV tropism is the addition of binding domains to the AAV capsid that recognize cell surface markers present on a targeted cell type. We have recently identified two previously unexplored capsid regions near the 2/5-fold wall and 5-fold pore of the AAV capsid that are amenable to insertion of larger protein domains, including nanobodies. Here, we demonstrate that these hotspots facilitate AAV tropism switching through simple nanobody replacement without extensive optimization in both VP1 and VP2. Our data suggest that engineering VP2 is the preferred path for maintaining both virus production yield and infectivity. We demonstrate highly specific targeting of human cancer cells expressing fibroblast activating protein (FAP). Furthermore, we found that the combination of FAP nanobody insertion plus ablation of the heparin binding domain can reduce off-target infection to a minimum, while maintaining a strong infection of FAP receptor-positive cells. Taken together, our study shows that nanobody swapping at multiple capsid locations is a viable strategy for nanobody-directed cell-specific AAV targeting.
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Affiliation(s)
- Mareike D Hoffmann
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Joseph P Gallant
- Department of Pathology and Laboratory Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792, USA
| | - Aaron M LeBeau
- Department of Pathology and Laboratory Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792, USA
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792, USA
| | - Daniel Schmidt
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN 55455, USA
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6
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Gurrola TE, Effah SN, Sariyer IK, Dampier W, Nonnemacher MR, Wigdahl B. Delivering CRISPR to the HIV-1 reservoirs. Front Microbiol 2024; 15:1393974. [PMID: 38812680 PMCID: PMC11133543 DOI: 10.3389/fmicb.2024.1393974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 04/22/2024] [Indexed: 05/31/2024] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) infection is well known as one of the most complex and difficult viral infections to cure. The difficulty in developing curative strategies arises in large part from the development of latent viral reservoirs (LVRs) within anatomical and cellular compartments of a host. The clustered regularly interspaced short palindromic repeats/ CRISPR-associated protein 9 (CRISPR/Cas9) system shows remarkable potential for the inactivation and/or elimination of integrated proviral DNA within host cells, however, delivery of the CRISPR/Cas9 system to infected cells is still a challenge. In this review, the main factors impacting delivery, the challenges for delivery to each of the LVRs, and the current successes for delivery to each reservoir will be discussed.
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Affiliation(s)
- Theodore E. Gurrola
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States
- Center for Molecular Virology and Gene Therapy, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Samuel N. Effah
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States
- Center for Molecular Virology and Gene Therapy, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Ilker K. Sariyer
- Department of Microbiology, Immunology, and Inflammation and Center for Neurovirology and Gene Editing, Temple University Lewis Katz School of Medicine, Philadelphia, PA, United States
| | - Will Dampier
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States
- Center for Molecular Virology and Gene Therapy, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Michael R. Nonnemacher
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States
- Center for Molecular Virology and Gene Therapy, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, United States
- Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, United States
| | - Brian Wigdahl
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States
- Center for Molecular Virology and Gene Therapy, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, United States
- Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, United States
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Hoffmann MD, Gallant JP, LeBeau AM, Schmidt D. Unlocking Precision Gene Therapy: Harnessing AAV Tropism with Nanobody Swapping at Capsid Hotspots. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.27.587049. [PMID: 38585985 PMCID: PMC10996663 DOI: 10.1101/2024.03.27.587049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Adeno-associated virus has been remarkably successful in the clinic, but its broad tropism is a practical limitation of precision gene therapy. A promising path to engineer AAV tropism is the addition of binding domains to the AAV capsid that recognize cell surface markers present on a targeted cell type. We have recently identified two previously unexplored capsid regions near the 2-fold valley and 5-fold pore of the AAV capsid that are amenable to insertion of larger protein domains including nanobodies. Here, we demonstrate that these hotspots facilitate AAV tropism switching through simple nanobody replacement without extensive optimization in both VP1 and VP2. We demonstrate highly specific targeting of human cancer cells expressing fibroblast activating protein (FAP). Our data suggest that engineering VP2 is the preferred path for maintaining both virus production yield and infectivity. Our study shows that nanobody swapping at multiple capsid location is a viable strategy for nanobody-directed cell-specific AAV targeting.
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Affiliation(s)
- Mareike D. Hoffmann
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Joseph P. Gallant
- Department of Pathology and Laboratory Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792, United States
| | - Aaron M. LeBeau
- Department of Pathology and Laboratory Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792, United States
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792, United States
| | - Daniel Schmidt
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN, 55455, USA
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8
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Du J, Kong Y, Wen Y, Shen E, Xing H. HUH Endonuclease: A Sequence-specific Fusion Protein Tag for Precise DNA-Protein Conjugation. Bioorg Chem 2024; 144:107118. [PMID: 38330720 DOI: 10.1016/j.bioorg.2024.107118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 01/01/2024] [Accepted: 01/09/2024] [Indexed: 02/10/2024]
Abstract
Synthetic DNA-protein conjugates have found widespread applications in diagnostics and therapeutics, prompting a growing interest in developing chemical biology methodologies for the precise and site-specific preparation of covalent DNA-protein conjugates. In this review article, we concentrate on techniques to achieve precise control over the structural and site-specific aspects of DNA-protein conjugates. We summarize conventional methods involving unnatural amino acids and self-labeling proteins, accompanied by a discussion of their potential limitations. Our primary focus is on introducing HUH endonuclease as a novel generation of fusion protein tags for DNA-protein conjugate preparation. The detailed conjugation mechanisms and structures of representative endonucleases are surveyed, showcasing their advantages as fusion protein tag in sequence selectivity, biological orthogonality, and no requirement for DNA modification. Additionally, we present the burgeoning applications of HUH-tag-based DNA-protein conjugates in protein assembly, biosensing, and gene editing. Furthermore, we delve into the future research directions of the HUH-tag, highlighting its significant potential for applications in the biomedical and DNA nanotechnology fields.
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Affiliation(s)
- Jiajun Du
- Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Biomacromolecular Chemical Biology, School of Chemistry and Chemical Engineering Hunan University Changsha, Hunan 410082, PR China
| | - Yuhan Kong
- Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Biomacromolecular Chemical Biology, School of Chemistry and Chemical Engineering Hunan University Changsha, Hunan 410082, PR China
| | - Yujian Wen
- Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Biomacromolecular Chemical Biology, School of Chemistry and Chemical Engineering Hunan University Changsha, Hunan 410082, PR China
| | - Enxi Shen
- Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Biomacromolecular Chemical Biology, School of Chemistry and Chemical Engineering Hunan University Changsha, Hunan 410082, PR China
| | - Hang Xing
- Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Biomacromolecular Chemical Biology, School of Chemistry and Chemical Engineering Hunan University Changsha, Hunan 410082, PR China.
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9
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Hoffmann MD, Zdechlik AC, He Y, Nedrud D, Aslanidi G, Gordon W, Schmidt D. Multiparametric domain insertional profiling of adeno-associated virus VP1. Mol Ther Methods Clin Dev 2023; 31:101143. [PMID: 38027057 PMCID: PMC10661864 DOI: 10.1016/j.omtm.2023.101143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 10/21/2023] [Indexed: 12/01/2023]
Abstract
Several evolved properties of adeno-associated virus (AAV), such as broad tropism and immunogenicity in humans, are barriers to AAV-based gene therapy. Most efforts to re-engineer these properties have focused on variable regions near AAV's 3-fold protrusions and capsid protein termini. To comprehensively survey AAV capsids for engineerable hotspots, we determined multiple AAV fitness phenotypes upon insertion of six structured protein domains into the entire AAV-DJ capsid protein VP1. This is the largest and most comprehensive AAV domain insertion dataset to date. Our data revealed a surprising robustness of AAV capsids to accommodate large domain insertions. Insertion permissibility depended strongly on insertion position, domain type, and measured fitness phenotype, which clustered into contiguous structural units that we could link to distinct roles in AAV assembly, stability, and infectivity. We also identified engineerable hotspots of AAV that facilitate the covalent attachment of binding scaffolds, which may represent an alternative approach to re-direct AAV tropism.
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Affiliation(s)
- Mareike D. Hoffmann
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Alina C. Zdechlik
- Department of Biochemistry, Molecular Biology & Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Yungui He
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - David Nedrud
- Department of Biochemistry, Molecular Biology & Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | | | - Wendy Gordon
- Department of Biochemistry, Molecular Biology & Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Daniel Schmidt
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN 55455, USA
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10
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Limón LK, Shi K, Dao A, Rugloski J, Tompkins KJ, Aihara H, Gordon WR, Evans RL. The crystal structure of the human smacovirus 1 Rep domain. Acta Crystallogr F Struct Biol Commun 2023; 79:295-300. [PMID: 38051309 PMCID: PMC10833120 DOI: 10.1107/s2053230x23009536] [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: 08/23/2023] [Accepted: 10/31/2023] [Indexed: 12/07/2023] Open
Abstract
Replication initiator proteins (Reps) from the HUH endonuclease family process specific single-stranded DNA sequences to initiate rolling-circle replication in viruses. Here, the first crystal structure of the apo state of a Rep domain from the smacovirus family is reported. The structure of the human smacovirus 1 Rep domain was obtained at 1.33 Å resolution and represents an expansion of the HUH endonuclease superfamily, allowing greater diversity in bioconjugation-tag applications.
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Affiliation(s)
- Lidia K. Limón
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Ke Shi
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Amy Dao
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Jacob Rugloski
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Kassidy J. Tompkins
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Hideki Aihara
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Wendy R. Gordon
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Robert L. Evans
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
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11
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Hoffmann MD, Zdechlik AC, He Y, Nedrud D, Aslanidi G, Gordon W, Schmidt D. Multiparametric domain insertional profiling of Adeno-Associated Virus VP1. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.19.537549. [PMID: 37131661 PMCID: PMC10153220 DOI: 10.1101/2023.04.19.537549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Evolved properties of Adeno-Associated Virus (AAV), such as broad tropism and immunogenicity in humans, are barriers to AAV-based gene therapy. Previous efforts to re-engineer these properties have focused on variable regions near AAV’s 3-fold protrusions and capsid protein termini. To comprehensively survey AAV capsids for engineerable hotspots, we determined multiple AAV fitness phenotypes upon insertion of large, structured protein domains into the entire AAV-DJ capsid protein VP1. This is the largest and most comprehensive AAV domain insertion dataset to date. Our data revealed a surprising robustness of AAV capsids to accommodate large domain insertions. There was strong positional, domain-type, and fitness phenotype dependence of insertion permissibility, which clustered into correlated structural units that we could link to distinct roles in AAV assembly, stability, and infectivity. We also identified new engineerable hotspots of AAV that facilitate the covalent attachment of binding scaffolds, which may represent an alternative approach to re-direct AAV tropism.
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12
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Smiley AT, Tompkins KJ, Pawlak MR, Krueger AJ, Evans RL, Shi K, Aihara H, Gordon WR. Watson-Crick Base-Pairing Requirements for ssDNA Recognition and Processing in Replication-Initiating HUH Endonucleases. mBio 2023; 14:e0258722. [PMID: 36541758 PMCID: PMC9973303 DOI: 10.1128/mbio.02587-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 12/05/2022] [Indexed: 12/24/2022] Open
Abstract
Replication-initiating HUH endonucleases (Reps) are sequence-specific nucleases that cleave and rejoin single-stranded DNA (ssDNA) during rolling-circle replication. These functions are mediated by covalent linkage of the Rep to its substrate post cleavage. Here, we describe the structures of the endonuclease domain from the Muscovy duck circovirus Rep in complex with its cognate ssDNA 10-mer with and without manganese in the active site. Structural and functional analyses demonstrate that divalent cations play both catalytic and structural roles in Reps by polarizing and positioning their substrate. Further structural comparisons highlight the importance of an intramolecular substrate Watson-Crick (WC) base pairing between the -4 and +1 positions. Subsequent kinetic and functional analyses demonstrate a functional dependency on WC base pairing between these positions regardless of the pair's identity (i.e., A·T, T·A, G·C, or C·G), highlighting a structural specificity for substrate interaction. Finally, considering how well WC swaps were tolerated in vitro, we sought to determine to what extent the canonical -4T·+1A pairing is conserved in circular Rep-encoding single-stranded DNA viruses and found evidence of noncanonical pairings in a minority of these genomes. Altogether, our data suggest that substrate intramolecular WC base pairing is a universal requirement for separation and reunion of ssDNA in Reps. IMPORTANCE Circular Rep-encoding single-stranded DNA (CRESS-DNA) viruses are a ubiquitous group of viruses that infect organisms across all domains of life. These viruses negatively impact both agriculture and human health. All members of this viral family employ a multifunctional nuclease (Rep) to initiate replication. Reps are structurally similar throughout this family, making them targets of interest for viral inhibition strategies. Here, we investigate the functional dependencies of the Rep protein from Muscovy duck circovirus for ssDNA interaction. We demonstrate that this Rep requires an intramolecular Watson-Crick base pairing for origin of replication (Ori) recognition and interaction. We show that noncognate base pair swaps are well tolerated, highlighting a local structural specificity over sequence specificity. Bioinformatic analysis found that the vast majority of CRESS-DNA Oris form base pairs in conserved positions, suggesting this pairing is a universal requirement for replication initiation in the CRESS-DNA virus family.
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Affiliation(s)
- Adam T. Smiley
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Kassidy J. Tompkins
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Matthew R. Pawlak
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - August J. Krueger
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Robert L. Evans
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Ke Shi
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Hideki Aihara
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Wendy R. Gordon
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
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Becker J, Fakhiri J, Grimm D. Fantastic AAV Gene Therapy Vectors and How to Find Them—Random Diversification, Rational Design and Machine Learning. Pathogens 2022; 11:pathogens11070756. [PMID: 35890005 PMCID: PMC9318892 DOI: 10.3390/pathogens11070756] [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: 05/23/2022] [Revised: 06/30/2022] [Accepted: 07/01/2022] [Indexed: 11/16/2022] Open
Abstract
Parvoviruses are a diverse family of small, non-enveloped DNA viruses that infect a wide variety of species, tissues and cell types. For over half a century, their intriguing biology and pathophysiology has fueled intensive research aimed at dissecting the underlying viral and cellular mechanisms. Concurrently, their broad host specificity (tropism) has motivated efforts to develop parvoviruses as gene delivery vectors for human cancer or gene therapy applications. While the sum of preclinical and clinical data consistently demonstrates the great potential of these vectors, these findings also illustrate the importance of enhancing and restricting in vivo transgene expression in desired cell types. To this end, major progress has been made especially with vectors based on Adeno-associated virus (AAV), whose capsid is highly amenable to bioengineering, repurposing and expansion of its natural tropism. Here, we provide an overview of the state-of-the-art approaches to create new AAV variants with higher specificity and efficiency of gene transfer in on-target cells. We first review traditional and novel directed evolution approaches, including high-throughput screening of AAV capsid libraries. Next, we discuss programmable receptor-mediated targeting with a focus on two recent technologies that utilize high-affinity binders. Finally, we highlight one of the latest stratagems for rational AAV vector characterization and optimization, namely, machine learning, which promises to facilitate and accelerate the identification of next-generation, safe and precise gene delivery vehicles.
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Affiliation(s)
- Jonas Becker
- Department of Infectious Diseases/Virology, Medical Faculty, University of Heidelberg, Center for Integrative Infectious Diseases Research (CIID), BioQuant, 69120 Heidelberg, Germany;
- Faculty of Biosciences, University of Heidelberg, 69120 Heidelberg, Germany
| | - Julia Fakhiri
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Munich, Roche Diagnostics GmbH, Nonnenwald 2, 82377 Penzberg, Germany
- Correspondence: (J.F.); (D.G.); Tel.: +49-174-3486203 (J.F.); +49-6221-5451331 (D.G.)
| | - Dirk Grimm
- Department of Infectious Diseases/Virology, Medical Faculty, University of Heidelberg, Center for Integrative Infectious Diseases Research (CIID), BioQuant, 69120 Heidelberg, Germany;
- German Center for Infection Research (DZIF), Partner Site Heidelberg, 69120 Heidelberg, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg, 69120 Heidelberg, Germany
- Correspondence: (J.F.); (D.G.); Tel.: +49-174-3486203 (J.F.); +49-6221-5451331 (D.G.)
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Korneyenkov MA, Zamyatnin AA. Next Step in Gene Delivery: Modern Approaches and Further Perspectives of AAV Tropism Modification. Pharmaceutics 2021; 13:pharmaceutics13050750. [PMID: 34069541 PMCID: PMC8160765 DOI: 10.3390/pharmaceutics13050750] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 05/14/2021] [Accepted: 05/17/2021] [Indexed: 11/16/2022] Open
Abstract
Today, adeno-associated virus (AAV) is an extremely popular choice for gene therapy delivery. The safety profile and simplicity of the genome organization are the decisive advantages which allow us to claim that AAV is currently among the most promising vectors. Several drugs based on AAV have been approved in the USA and Europe, but AAV serotypes’ unspecific tissue tropism is still a serious limitation. In recent decades, several techniques have been developed to overcome this barrier, such as the rational design, directed evolution and chemical conjugation of targeting molecules with a capsid. Today, all of the abovementioned approaches confer the possibility to produce AAV capsids with tailored tropism, but recent data indicate that a better understanding of AAV biology and the growth of structural data may theoretically constitute a rational approach to most effectively produce highly selective and targeted AAV capsids. However, while we are still far from this goal, other approaches are still in play, despite their drawbacks and limitations.
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Affiliation(s)
- Maxim A. Korneyenkov
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, 119991 Moscow, Russia;
| | - Andrey A. Zamyatnin
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, 119991 Moscow, Russia
- Department of Biotechnology, Sirius University of Science and Technology, 1 Olympic Ave, 354340 Sochi, Russia
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119992 Moscow, Russia
- Correspondence: ; Tel.: +7-495-622-9843
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Wagner HJ, Weber W, Fussenegger M. Synthetic Biology: Emerging Concepts to Design and Advance Adeno-Associated Viral Vectors for Gene Therapy. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:2004018. [PMID: 33977059 PMCID: PMC8097373 DOI: 10.1002/advs.202004018] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 12/18/2020] [Indexed: 05/28/2023]
Abstract
Three recent approvals and over 100 ongoing clinical trials make adeno-associated virus (AAV)-based vectors the leading gene delivery vehicles in gene therapy. Pharmaceutical companies are investing in this small and nonpathogenic gene shuttle to increase the therapeutic portfolios within the coming years. This prospect of marking a new era in gene therapy has fostered both investigations of the fundamental AAV biology as well as engineering studies to enhance delivery vehicles. Driven by the high clinical potential, a new generation of synthetic-biologically engineered AAV vectors is on the rise. Concepts from synthetic biology enable the control and fine-tuning of vector function at different stages of cellular transduction and gene expression. It is anticipated that the emerging field of synthetic-biologically engineered AAV vectors can shape future gene therapeutic approaches and thus the design of tomorrow's gene delivery vectors. This review describes and discusses the recent trends in capsid and vector genome engineering, with particular emphasis on synthetic-biological approaches.
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Affiliation(s)
- Hanna J. Wagner
- Department of Biosystems Science and EngineeringETH ZurichMattenstrasse 26Basel4058Switzerland
- Faculty of BiologyUniversity of FreiburgSchänzlestraße 1Freiburg79104Germany
- Signalling Research Centres BIOSS and CIBSSUniversity of FreiburgSchänzlestraße 18Freiburg79104Germany
| | - Wilfried Weber
- Faculty of BiologyUniversity of FreiburgSchänzlestraße 1Freiburg79104Germany
- Signalling Research Centres BIOSS and CIBSSUniversity of FreiburgSchänzlestraße 18Freiburg79104Germany
| | - Martin Fussenegger
- Department of Biosystems Science and EngineeringETH ZurichMattenstrasse 26Basel4058Switzerland
- Faculty of ScienceUniversity of BaselKlingelbergstrasse 50Basel4056Switzerland
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Tompkins KJ, Houtti M, Litzau LA, Aird EJ, Everett BA, Nelson AT, Pornschloegl L, Limón-Swanson LK, Evans RL, Evans K, Shi K, Aihara H, Gordon WR. Molecular underpinnings of ssDNA specificity by Rep HUH-endonucleases and implications for HUH-tag multiplexing and engineering. Nucleic Acids Res 2021; 49:1046-1064. [PMID: 33410911 PMCID: PMC7826260 DOI: 10.1093/nar/gkaa1248] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 12/08/2020] [Accepted: 12/14/2020] [Indexed: 12/11/2022] Open
Abstract
Replication initiator proteins (Reps) from the HUH-endonuclease superfamily process specific single-stranded DNA (ssDNA) sequences to initiate rolling circle/hairpin replication in viruses, such as crop ravaging geminiviruses and human disease causing parvoviruses. In biotechnology contexts, Reps are the basis for HUH-tag bioconjugation and a critical adeno-associated virus genome integration tool. We solved the first co-crystal structures of Reps complexed to ssDNA, revealing a key motif for conferring sequence specificity and for anchoring a bent DNA architecture. In combination, we developed a deep sequencing cleavage assay, termed HUH-seq, to interrogate subtleties in Rep specificity and demonstrate how differences can be exploited for multiplexed HUH-tagging. Together, our insights allowed engineering of only four amino acids in a Rep chimera to predictably alter sequence specificity. These results have important implications for modulating viral infections, developing Rep-based genomic integration tools, and enabling massively parallel HUH-tag barcoding and bioconjugation applications.
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Affiliation(s)
- Kassidy J Tompkins
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Mo Houtti
- Department of Computer Science and Engineering, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Lauren A Litzau
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Eric J Aird
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Blake A Everett
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Andrew T Nelson
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Leland Pornschloegl
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Lidia K Limón-Swanson
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Robert L Evans
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Karen Evans
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Ke Shi
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Hideki Aihara
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Wendy R Gordon
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
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Breaking the sound barrier: Towards next-generation AAV vectors for gene therapy of hearing disorders. Hear Res 2020; 413:108092. [PMID: 33268240 DOI: 10.1016/j.heares.2020.108092] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 09/14/2020] [Accepted: 10/08/2020] [Indexed: 12/20/2022]
Abstract
Owing to the advances in transgenic animal technology and the advent of the next-generation sequencing era, over 120 genes causing hereditary hearing loss have been identified by now. In parallel, the field of human gene therapy continues to make exciting and rapid progress, culminating in the recent approval of several ex vivo and in vivo applications. Despite these encouraging developments and the growing interest in causative treatments for hearing disorders, gene therapeutic interventions in the inner ear remain in their infancy and await clinical translation. This review focuses on the adeno-associated virus (AAV), which nowadays represents one of the safest and most promising vectors in gene therapy. We first provide an overview of AAV biology and outline the principles of therapeutic gene transfer with recombinant AAV vectors, before pointing out major challenges and solutions for clinical translation including vector manufacturing and species translatability. Finally, we highlight seminal technologies for engineering and selection of next-generation "designer" AAV capsids, and illustrate their power and potential with recent examples of their application for inner ear gene transfer in animals.
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