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Froehlich T, Jenner A, Cavarischia-Rega C, Fagbadebo FO, Lurz Y, Frecot DI, Kaiser PD, Nueske S, Scholz AM, Schäffer E, Garcia-Saez AJ, Macek B, Rothbauer U. Nanobodies as novel tools to monitor the mitochondrial fission factor Drp1. Life Sci Alliance 2024; 7:e202402608. [PMID: 38816213 PMCID: PMC11140114 DOI: 10.26508/lsa.202402608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 05/14/2024] [Accepted: 05/15/2024] [Indexed: 06/01/2024] Open
Abstract
In cells, mitochondria undergo constant fusion and fission. An essential factor for fission is the mammalian dynamin-related protein 1 (Drp1). Dysregulation of Drp1 is associated with neurodegenerative diseases including Parkinson's, cardiovascular diseases and cancer, making Drp1 a pivotal biomarker for monitoring mitochondrial status and potential pathophysiological conditions. Here, we developed nanobodies (Nbs) as versatile binding molecules for proteomics, advanced microscopy and live cell imaging of Drp1. To specifically enrich endogenous Drp1 with interacting proteins for proteomics, we functionalized high-affinity Nbs into advanced capture matrices. Furthermore, we detected Drp1 by bivalent Nbs combined with site-directed fluorophore labelling in super-resolution STORM microscopy. For real-time imaging of Drp1, we intracellularly expressed fluorescently labelled Nbs, so-called chromobodies (Cbs). To improve the signal-to-noise ratio, we further converted Cbs into a "turnover-accelerated" format. With these imaging probes, we visualized the dynamics of endogenous Drp1 upon compound-induced mitochondrial fission in living cells. Considering the wide range of research applications, the presented Nb toolset will open up new possibilities for advanced functional studies of Drp1 in disease-relevant models.
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Affiliation(s)
- Theresa Froehlich
- Pharmaceutical Biotechnology, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Andreas Jenner
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Claudia Cavarischia-Rega
- Quantitative Proteomics, Department of Biology, Institute of Cell Biology, Eberhard Karls University Tübingen, Tübingen, Germany
| | | | - Yannic Lurz
- Center for Plant Molecular Biology (ZMBP), Eberhard Karls University Tübingen, Tübingen, Germany
| | - Desiree I Frecot
- Pharmaceutical Biotechnology, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Philipp D Kaiser
- https://ror.org/03a1kwz48 NMI Natural and Medical Sciences Institute at the University of Tübingen, Reutlingen, Germany
| | - Stefan Nueske
- Livestock Center of the Faculty of Veterinary Medicine, Ludwig Maximilians University Munich, Munich, Germany
| | - Armin M Scholz
- Livestock Center of the Faculty of Veterinary Medicine, Ludwig Maximilians University Munich, Munich, Germany
| | - Erik Schäffer
- Center for Plant Molecular Biology (ZMBP), Eberhard Karls University Tübingen, Tübingen, Germany
| | - Ana J Garcia-Saez
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Boris Macek
- Quantitative Proteomics, Department of Biology, Institute of Cell Biology, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Ulrich Rothbauer
- Pharmaceutical Biotechnology, Eberhard Karls University Tübingen, Tübingen, Germany
- https://ror.org/03a1kwz48 Cluster of Excellence iFIT (EXC2180) "Image-Guided and Functionally Instructed Tumor Therapies," University of Tübingen, Tübingen, Germany
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2
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D'Brant L, Rugenstein N, Na SK, Miller MJ, Czajka TF, Trudeau N, Fitz E, Tomaszek L, Fisher ES, Mash E, Joy S, Lotz S, Borden S, Stevens K, Goderie SK, Wang Y, Bertucci T, Karch CM, Temple S, Butler DC. Fully Human Bifunctional Intrabodies Achieve Graded Reduction of Intracellular Tau and Rescue Survival of MAPT Mutation iPSC-derived Neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.28.596248. [PMID: 38854137 PMCID: PMC11160687 DOI: 10.1101/2024.05.28.596248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Tau protein aggregation is a hallmark of several neurodegenerative diseases, including Alzheimer's disease, frontotemporal dementia (FTD) and progressive supranuclear palsy (PSP), spurring development of tau-lowering therapeutic strategies. Here, we report fully human bifunctional anti-tau-PEST intrabodies that bind the mid-domain of tau to block aggregation and degrade tau via the proteasome using the ornithine decarboxylase (ODC) PEST degron. They effectively reduced tau protein in human iPSC-derived cortical neurons in 2D cultures and 3D organoids, including those with the disease-associated tau mutations R5L, N279K, R406W, and V337M. Anti-tau-hPEST intrabodies facilitated efficient ubiquitin-independent proteolysis, in contrast to tau-lowering approaches that rely on the cell's ubiquitination system. Importantly, they counteracted the proteasome impairment observed in V337M patient-derived cortical neurons and significantly improved neuronal survival. By serial mutagenesis, we created variants of the PEST degron that achieved graded levels of tau reduction. Moderate reduction was as effective as high reduction against tau V337M-induced neural cell death.
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3
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Traenkle B, Segan S, Fagbadebo FO, Kaiser PD, Rothbauer U. A novel epitope tagging system to visualize and monitor antigens in live cells with chromobodies. Sci Rep 2020; 10:14267. [PMID: 32868807 PMCID: PMC7459311 DOI: 10.1038/s41598-020-71091-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 08/06/2020] [Indexed: 11/09/2022] Open
Abstract
Epitope tagging is a versatile approach to study different proteins using a well-defined and established methodology. To date, most epitope tags such as myc, HA, V5 and FLAG tags are recognized by antibodies, which limits their use to fixed cells, tissues or protein samples. Here we introduce a broadly applicable tagging strategy utilizing a short peptide tag (PepTag) which is specifically recognized by a nanobody (PepNB). We demonstrated that the PepNB can be easily functionalized for immunoprecipitation or direct immunofluorescence staining of Pep-tagged proteins in vitro. For in cellulo studies we converted the PepNB into a fluorescently labeled Pep-chromobody (PepCB) which is functionally expressed in living cells. The addition of the small PepTag does not interfere with the examined structures in different cellular compartments and its detection with the PepCB enables optical antigen tracing in real time. By employing the phenomenon of antigen-mediated chromobody stabilization (AMCBS) using a turnover-accelerated PepCB we demonstrated that the system is suitable to visualize and quantify changes in Pep-tagged antigen concentration by quantitative live-cell imaging. We expect that this novel tagging strategy offers new opportunities to study the dynamic regulation of proteins, e.g. during cellular signaling, cell differentiation, or upon drug action.
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Affiliation(s)
- Bjoern Traenkle
- Pharmaceutical Biotechnology, Eberhard Karls University, Tuebingen, Germany.,Natural and Medical Sciences Institute, University of Tuebingen, Markwiesenstr. 55, 72770, Reutlingen, Germany
| | - Sören Segan
- Natural and Medical Sciences Institute, University of Tuebingen, Markwiesenstr. 55, 72770, Reutlingen, Germany
| | | | - Philipp D Kaiser
- Natural and Medical Sciences Institute, University of Tuebingen, Markwiesenstr. 55, 72770, Reutlingen, Germany
| | - Ulrich Rothbauer
- Pharmaceutical Biotechnology, Eberhard Karls University, Tuebingen, Germany. .,Natural and Medical Sciences Institute, University of Tuebingen, Markwiesenstr. 55, 72770, Reutlingen, Germany.
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4
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Optimizing intracellular antibodies (intrabodies/nanobodies) to treat neurodegenerative disorders. Neurobiol Dis 2020; 134:104619. [DOI: 10.1016/j.nbd.2019.104619] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 09/05/2019] [Accepted: 09/19/2019] [Indexed: 01/27/2023] Open
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5
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Lopez‐Barbosa N, Ludwicki MB, DeLisa MP. Proteome editing using engineered proteins that hijack cellular quality control machinery. AIChE J 2019. [DOI: 10.1002/aic.16854] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Natalia Lopez‐Barbosa
- Robert F. Smith School of Chemical and Biomolecular Engineering Cornell University Ithaca New York
| | - Morgan B. Ludwicki
- Robert F. Smith School of Chemical and Biomolecular Engineering Cornell University Ithaca New York
| | - Matthew P. DeLisa
- Robert F. Smith School of Chemical and Biomolecular Engineering Cornell University Ithaca New York
- Nancy E. and Peter C. Meinig School of Biomedical Engineering Cornell University Ithaca New York
- Biochemistry, Molecular and Cell Biology Cornell University Ithaca New York
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6
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Keller BM, Maier J, Secker KA, Egetemaier SM, Parfyonova Y, Rothbauer U, Traenkle B. Chromobodies to Quantify Changes of Endogenous Protein Concentration in Living Cells. Mol Cell Proteomics 2018; 17:2518-2533. [PMID: 30228193 DOI: 10.1074/mcp.tir118.000914] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 09/04/2018] [Indexed: 11/06/2022] Open
Abstract
Understanding cellular processes requires the determination of dynamic changes in the concentration of genetically nonmodified, endogenous proteins, which, to date, is commonly accomplished by end-point assays in vitro Molecular probes such as fluorescently labeled nanobodies (chromobodies, CBs) are powerful tools to visualize the dynamic subcellular localization of endogenous proteins in living cells. Here, we employed the dependence of intracellular levels of chromobodies on the amount of their endogenous antigens, a phenomenon, which we termed antigen-mediated CB stabilization (AMCBS), for simultaneous monitoring of time-resolved changes in the concentration and localization of native proteins. To improve the dynamic range of AMCBS we generated turnover-accelerated CBs and demonstrated their application in visualization and quantification of fast reversible changes in antigen concentration upon compound treatment by quantitative live-cell imaging. We expect that this broadly applicable strategy will enable unprecedented insights into the dynamic regulation of proteins, e.g. during cellular signaling, cell differentiation, or upon drug action.
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Affiliation(s)
| | - Julia Maier
- Pharmaceutical Biotechnology, Eberhard Karls University Tuebingen, Germany
| | - Kathy-Ann Secker
- Pharmaceutical Biotechnology, Eberhard Karls University Tuebingen, Germany
| | | | - Yana Parfyonova
- Pharmaceutical Biotechnology, Eberhard Karls University Tuebingen, Germany
| | - Ulrich Rothbauer
- Pharmaceutical Biotechnology, Eberhard Karls University Tuebingen, Germany; Natural and Medical Sciences Institute at the University of Tuebingen, Reutlingen, Germany.
| | - Bjoern Traenkle
- Pharmaceutical Biotechnology, Eberhard Karls University Tuebingen, Germany.
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7
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Traenkle B, Rothbauer U. Under the Microscope: Single-Domain Antibodies for Live-Cell Imaging and Super-Resolution Microscopy. Front Immunol 2017; 8:1030. [PMID: 28883823 PMCID: PMC5573807 DOI: 10.3389/fimmu.2017.01030] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 08/09/2017] [Indexed: 12/12/2022] Open
Abstract
Single-domain antibodies (sdAbs) have substantially expanded the possibilities of advanced cellular imaging such as live-cell or super-resolution microscopy to visualize cellular antigens and their dynamics. In addition to their unique properties including small size, high stability, and solubility in many environments, sdAbs can be efficiently functionalized according to the needs of the respective imaging approach. Genetically encoded intrabodies fused to fluorescent proteins (chromobodies) have become versatile tools to study dynamics of endogenous proteins in living cells. Additionally, sdAbs conjugated to organic dyes were shown to label cellular structures with high density and minimal fluorophore displacement making them highly attractive probes for super-resolution microscopy. Here, we review recent advances of the chromobody technology to visualize localization and dynamics of cellular targets and the application of chromobody-based cell models for compound screening. Acknowledging the emerging importance of super-resolution microscopy in cell biology, we further discuss advantages and challenges of sdAbs for this technology.
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Affiliation(s)
- Bjoern Traenkle
- Pharmaceutical Biotechnology, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Ulrich Rothbauer
- Pharmaceutical Biotechnology, Eberhard Karls University Tuebingen, Tuebingen, Germany.,Natural and Medical Sciences Institute at the University of Tuebingen, Reutlingen, Germany
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8
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Traenkle B, Emele F, Anton R, Poetz O, Haeussler RS, Maier J, Kaiser PD, Scholz AM, Nueske S, Buchfellner A, Romer T, Rothbauer U. Monitoring interactions and dynamics of endogenous beta-catenin with intracellular nanobodies in living cells. Mol Cell Proteomics 2015; 14:707-23. [PMID: 25595278 DOI: 10.1074/mcp.m114.044016] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
β-catenin is the key component of the canonical Wnt pathway and plays a crucial role in a multitude of developmental and homeostatic processes. The different tasks of β-catenin are orchestrated by its subcellular localization and participation in multiprotein complexes. To gain a better understanding of β-catenin's role in living cells we have generated a new set of single domain antibodies, referred to as nanobodies, derived from heavy chain antibodies of camelids. We selected nanobodies recognizing the N-terminal, core or C-terminal domain of β-catenin and applied these new high-affinity binders as capture molecules in sandwich immunoassays and co-immunoprecipitations of endogenous β-catenin complexes. In addition, we engineered intracellularly functional anti-β-catenin chromobodies by combining the binding moieties of the nanobodies with fluorescent proteins. For the first time, we were able to visualize the subcellular localization and nuclear translocation of endogenous β-catenin in living cells using these chromobodies. Moreover, the chromobody signal allowed us to trace the accumulation of diffusible, hypo-phosphorylated β-catenin in response to compound treatment in real time using High Content Imaging. The anti-β-catenin nanobodies and chromobodies characterized in this study are versatile tools that enable a novel and unique approach to monitor the dynamics of subcellular β-catenin in biochemical and cell biological assays.
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Affiliation(s)
- Bjoern Traenkle
- From the ‡Pharmaceutical Biotechnology, Eberhard-Karls University Tuebingen, Germany
| | - Felix Emele
- From the ‡Pharmaceutical Biotechnology, Eberhard-Karls University Tuebingen, Germany
| | - Roman Anton
- From the ‡Pharmaceutical Biotechnology, Eberhard-Karls University Tuebingen, Germany
| | - Oliver Poetz
- §Natural and Medical Sciences Institute at the University of Tuebingen, Reutlingen, Germany
| | - Ragna S Haeussler
- §Natural and Medical Sciences Institute at the University of Tuebingen, Reutlingen, Germany
| | - Julia Maier
- From the ‡Pharmaceutical Biotechnology, Eberhard-Karls University Tuebingen, Germany
| | - Philipp D Kaiser
- From the ‡Pharmaceutical Biotechnology, Eberhard-Karls University Tuebingen, Germany; §Natural and Medical Sciences Institute at the University of Tuebingen, Reutlingen, Germany
| | - Armin M Scholz
- ¶Livestock Center of the Faculty of Veterinary Medicine, Ludwig Maximilians University Munich, Oberschleissheim, Germany
| | - Stefan Nueske
- ¶Livestock Center of the Faculty of Veterinary Medicine, Ludwig Maximilians University Munich, Oberschleissheim, Germany
| | | | - Tina Romer
- ‖ChromoTek GmbH, Planegg-Martinsried, Germany
| | - Ulrich Rothbauer
- From the ‡Pharmaceutical Biotechnology, Eberhard-Karls University Tuebingen, Germany; §Natural and Medical Sciences Institute at the University of Tuebingen, Reutlingen, Germany;
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9
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Rinaldi AS, Freund G, Desplancq D, Sibler AP, Baltzinger M, Rochel N, Mély Y, Didier P, Weiss E. The use of fluorescent intrabodies to detect endogenous gankyrin in living cancer cells. Exp Cell Res 2013; 319:838-49. [PMID: 23353833 DOI: 10.1016/j.yexcr.2013.01.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 12/07/2012] [Accepted: 01/10/2013] [Indexed: 01/31/2023]
Abstract
Expression of antibody fragments in mammalian cells (intrabodies) is used to probe the target protein or interfere with its biological function. We previously described the in vitro characterisation of a single-chain Fv (scFv) antibody fragment (F5) isolated from an intrabody library that binds to the oncoprotein gankyrin (GK) in solution. Here, we have isolated several other scFvs that interact with GK in the presence of F5 and tested whether they allow, when fused to fluorescent proteins, to detect by FRET endogenous GK in living cells. The binding of pairs of scFvs to GK was analysed by gel filtration and the ability of each scFv to mediate nuclear import/export of GK was determined. Binding between scFv-EGFP and RFP-labelled GK in living cells was detected by fluorescence lifetime imaging microscopy (FLIM). After co-transfection of two scFvs fused to EGFP and RFP, respectively, which form a tri-molecular complex with GK in vitro, FRET signal was measured. This system allowed us to observe that GK is monomeric and distributed throughout the cytoplasm and nucleus of several cancer cell lines. Our results show that pairs of fluorescently labelled intrabodies can be monitored by FLIM-FRET microscopy and that this technique allows the detection of lowly expressed endogenous proteins in single living cells.
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Affiliation(s)
- Anne-Sophie Rinaldi
- Ecole Supérieure de Biotechnologie de Strasbourg, UMR 7242, CNRS/Université de Strasbourg, boulevard Sébastien Brant, 67412 Illkirch, France
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10
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Joshi SN, Butler DC, Messer A. Fusion to a highly charged proteasomal retargeting sequence increases soluble cytoplasmic expression and efficacy of diverse anti-synuclein intrabodies. MAbs 2012; 4:686-93. [PMID: 22929188 DOI: 10.4161/mabs.21696] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Intrabodies can be powerful reagents to effect modulation of aberrant intracellular proteins that underlie a range of diseases. However, their cytoplasmic solubility can be limiting. We previously reported that overall charge and hydrophilicity can be combined to provide initial estimates of intracellular solubility, and that charge engineering via fusion can alter solubility properties experimentally. Additional studies showed that fusion of a proteasome-targeting PEST motif to the anti-huntingtin intrabody scFv-C4 can degrade mutant huntingtin proteins by directing them to the proteasome, while also increasing the negative charge. We now validate the generality of this approach with intrabodies against α-synuclein (α-syn), an important target in Parkinson disease. In this study, fusion of the PEST sequence to a set of four diverse, poorly soluble anti-α-syn intrabodies (D5E, 10H, D10 scFv, VH14 nanobody) significantly increased steady-state soluble intrabody protein levels in all cases, despite fusion with the PEST proteasomal-targeting signal. Furthermore, adding this PEST motif to the least soluble construct, VH14, significantly enhanced degradation of the target protein, α-syn~GFP. The intrabody-PEST fusion approach thus has dual advantages of potentially solubilizing intrabodies and enhancing their functionality in parallel. Empirical testing of intrabody-PEST fusions is recommended for enhancement of intrabody solubility from diverse sources.
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Affiliation(s)
- Shubhada N Joshi
- Department of Neuropharmacology and Neuroscience, Albany Medical College, Albany, NY, USA
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11
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Butler DC, McLear JA, Messer A. Engineered antibody therapies to counteract mutant huntingtin and related toxic intracellular proteins. Prog Neurobiol 2012; 97:190-204. [PMID: 22120646 PMCID: PMC3908675 DOI: 10.1016/j.pneurobio.2011.11.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 11/03/2011] [Accepted: 11/08/2011] [Indexed: 02/07/2023]
Abstract
The engineered antibody approach to Huntington's disease (HD) therapeutics is based on the premise that significantly lowering the levels of the primary misfolded mutant protein will reduce abnormal protein interactions and direct toxic effects of the misfolded huntingtin (HTT). This will in turn reduce the pathologic stress on cells, and normalize intrinsic proteostasis. Intracellular antibodies (intrabodies) are single-chain (scFv) and single-domain (dAb; nanobody) variable fragments that can retain the affinity and specificity of full-length antibodies, but can be selected and engineered as genes. Functionally, they represent a protein-based approach to the problem of aberrant mutant protein folding, post-translational modifications, protein-protein interactions, and aggregation. Several intrabodies that bind on either side of the expanded polyglutamine tract of mutant HTT have been reported to improve the mutant phenotype in cell and organotypic cultures, fruit flies, and mice. Further refinements to the difficult challenges of intraneuronal delivery, cytoplasmic folding, and long-term efficacy are in progress. This review covers published studies and emerging approaches on the choice of targets, selection and engineering methods, gene and protein delivery options, and testing of candidates in cell and animal models. The resultant antibody fragments can be used as direct therapeutics and as target validation/drug discovery tools for HD, while the technology is also applicable to a wide range of neurodegenerative and other diseases that are triggered by toxic proteins.
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Affiliation(s)
- David C. Butler
- Wadsworth Center, New York State Dept. of Health, Albany, NY, United States, 12208
| | | | - Anne Messer
- Wadsworth Center, New York State Dept. of Health, Albany, NY, United States, 12208
- Department of Biomedical Sciences, School of Public Health, University at Albany, SUNY, NY 12201
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12
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Butler DC, Messer A. Bifunctional anti-huntingtin proteasome-directed intrabodies mediate efficient degradation of mutant huntingtin exon 1 protein fragments. PLoS One 2011; 6:e29199. [PMID: 22216210 PMCID: PMC3245261 DOI: 10.1371/journal.pone.0029199] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Accepted: 11/22/2011] [Indexed: 12/31/2022] Open
Abstract
Huntington's disease (HD) is a fatal autosomal dominant neurodegenerative disorder caused by a trinucleotide (CAG)(n) repeat expansion in the coding sequence of the huntingtin gene, and an expanded polyglutamine (>37Q) tract in the protein. This results in misfolding and accumulation of huntingtin protein (htt), formation of neuronal intranuclear and cytoplasmic inclusions, and neuronal dysfunction/degeneration. Single-chain Fv antibodies (scFvs), expressed as intrabodies that bind htt and prevent aggregation, show promise as immunotherapeutics for HD. Intrastriatal delivery of anti-N-terminal htt scFv-C4 using an adeno-associated virus vector (AAV2/1) significantly reduces the size and number of aggregates in HDR6/1 transgenic mice; however, this protective effect diminishes with age and time after injection. We therefore explored enhancing intrabody efficacy via fusions to heterologous functional domains. Proteins containing a PEST motif are often targeted for proteasomal degradation and generally have a short half life. In ST14A cells, fusion of the C-terminal PEST region of mouse ornithine decarboxylase (mODC) to scFv-C4 reduces htt exon 1 protein fragments with 72 glutamine repeats (httex1-72Q) by ~80-90% when compared to scFv-C4 alone. Proteasomal targeting was verified by either scrambling the mODC-PEST motif, or via proteasomal inhibition with epoxomicin. For these constructs, the proteasomal degradation of the scFv intrabody proteins themselves was reduced<25% by the addition of the mODC-PEST motif, with or without antigens. The remaining intrabody levels were amply sufficient to target N-terminal httex1-72Q protein fragment turnover. Critically, scFv-C4-PEST prevents aggregation and toxicity of httex1-72Q fragments at significantly lower doses than scFv-C4. Fusion of the mODC-PEST motif to intrabodies is a valuable general approach to specifically target toxic antigens to the proteasome for degradation.
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Affiliation(s)
- David C. Butler
- Wadsworth Center, New York State Department of Health, Albany, New York, United States of America
- Department of Biomedical Sciences, University at Albany, Albany, New York, United States of America
| | - Anne Messer
- Wadsworth Center, New York State Department of Health, Albany, New York, United States of America
- Department of Biomedical Sciences, University at Albany, Albany, New York, United States of America
- * E-mail:
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13
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Single-chain Fv fragment antibodies selected from an intrabody library as effective mono- or bivalent reagents for in vitro protein detection. J Immunol Methods 2011; 369:42-50. [PMID: 21501618 DOI: 10.1016/j.jim.2011.04.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2010] [Revised: 03/28/2011] [Accepted: 04/01/2011] [Indexed: 11/23/2022]
Abstract
In spite of their many potential applications, recombinant antibody molecules selected by phage display are rarely available commercially, one reason being the absence of robust bacterial expression systems that yield sufficient quantities of reagents for routine applications. We previously described the construction and validation of an intrabody library that allows the selection of single-chain Fv (scFv) fragments solubly expressed in the cytoplasm. Here, we show that it is possible to obtain monomeric scFvs binding specifically to human papillomavirus type 16 E6 and cellular gankyrin oncoproteins in quantities higher than 0.5 g/L of shake-flask culture in E. coli cytoplasm after auto-induction. In addition, stable bivalent scFvs of increased avidity were produced by tagging the scFvs with the dimeric glutathione-S-transferase enzyme (GST). These minibody-like molecules were further engineered by fusion with green fluorescent protein (GFPuv), leading to high yield of functional bivalent fluorescent antibody fragments. Our results demonstrate that scFvs selected from an intrabody library can be engineered into cost-effective bivalent reagents suitable for many biomedical and industrial applications.
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14
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Kvam E, Sierks MR, Shoemaker CB, Messer A. Physico-chemical determinants of soluble intrabody expression in mammalian cell cytoplasm. Protein Eng Des Sel 2010; 23:489-98. [PMID: 20378699 PMCID: PMC2865363 DOI: 10.1093/protein/gzq022] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Revised: 03/02/2010] [Accepted: 03/12/2010] [Indexed: 12/25/2022] Open
Abstract
Soluble antibody fragments are desirable not only as potential therapeutic and diagnostic agents for extracellular targets but also as 'intrabodies' for functional genomics, proteomics and gene therapy inside cells. However, antibody fragments are notoriously aggregation-prone when expressed intracellularly, due in part to unfavorable redox potential and macromolecular crowding in cell cytoplasm. Only a small proportion of intrabodies are soluble in cytoplasm and little is known about the sequence determinants that confer such stability. By comparing the cytoplasmic expression of several related human single-chain variable fragments and camelid V(HH)s in mammalian cells, we report that intrabody solubility is highly influenced by CDR content and is improved by an overall negative charge at cytoplasmic pH and reduced hydrophilicity. We hypothesize that ionic repulsion and weak hydrophobic interactions compensate, to different extents, for impaired disulfide bond formation in cytoplasm, thereby decreasing the risk for intrabody aggregation. As proof of principle, we demonstrate that the soluble expression of an aggregation-prone positively charged intrabody is modestly enhanced via cis or trans acidification using highly charged peptide tags (3XFLAG tag, SV40 NLS). These findings suggest that simple sequence analysis and electrostatic manipulation may aid in predicting and engineering solubility-enhanced intrabodies from antibody libraries for intracellular use.
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Affiliation(s)
- Erik Kvam
- New York State Department of Health, Wadsworth Center/ David Axelrod Institute, 120 New Scotland Ave., PO Box 22002, Albany, NY 12201-2002, USA
- Department of Biomedical Sciences, University at Albany, Albany, NY, USA
| | - Michael R. Sierks
- Department of Chemical Engineering, Arizona State University, Tempe, AZ, USA
| | - Charles B. Shoemaker
- Department of Biomedical Sciences, Tufts Cummings School of Veterinary Medicine, North Grafton, MA, USA
| | - Anne Messer
- New York State Department of Health, Wadsworth Center/ David Axelrod Institute, 120 New Scotland Ave., PO Box 22002, Albany, NY 12201-2002, USA
- Department of Biomedical Sciences, University at Albany, Albany, NY, USA
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15
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Didier P, Weiss E, Sibler AP, Philibert P, Martineau P, Bigot JY, Guidoni L. Femtosecond spectroscopy probes the folding quality of antibody fragments expressed as GFP fusions in the cytoplasm. Biochem Biophys Res Commun 2007; 366:878-84. [PMID: 18067857 DOI: 10.1016/j.bbrc.2007.11.141] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2007] [Accepted: 11/23/2007] [Indexed: 12/25/2022]
Abstract
Time-resolved femtosecond spectroscopy can improve the application of green fluorescent proteins (GFPs) as protein-folding reporters. The study of ultrafast excited-state dynamics (ESD) of GFP fused to single chain variable fragment (scFv) antibody fragments, allowed us to define and measure an empirical parameter that only depends on the folding quality (FQ) of the fusion. This method has been applied to the analysis of genetic fusions expressed in the bacterial cytoplasm and allowed us to distinguish folded and thus functional antibody fragments (high FQ) with respect to misfolded antibody fragments. Moreover, these findings were strongly correlated to the behavior of the same scFvs expressed in animal cells. This method is based on the sensitivity of the ESD to the modifications in the tertiary structure of the GFP induced by the aggregation state of the fusion partner. This approach may be applicable to the study of the FQ of polypeptides over-expressed under reducing conditions.
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Affiliation(s)
- P Didier
- Faculté de Pharmacie, UMR 7175, 74, route du Rhin, 67412 Illkirch, France
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16
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Philibert P, Stoessel A, Wang W, Sibler AP, Bec N, Larroque C, Saven JG, Courtête J, Weiss E, Martineau P. A focused antibody library for selecting scFvs expressed at high levels in the cytoplasm. BMC Biotechnol 2007; 7:81. [PMID: 18034894 PMCID: PMC2241821 DOI: 10.1186/1472-6750-7-81] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Accepted: 11/22/2007] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Intrabodies are defined as antibody molecules which are ectopically expressed inside the cell. Such intrabodies can be used to visualize or inhibit the targeted antigen in living cells. However, most antibody fragments cannot be used as intrabodies because they do not fold under the reducing conditions of the cell cytosol and nucleus. RESULTS We describe the construction and validation of a large synthetic human single chain antibody fragment library based on a unique framework and optimized for cytoplasmic expression. Focusing the library by mimicking the natural diversity of CDR3 loops ensured that the scFvs were fully human and functional. We show that the library is highly diverse and functional since it has been possible to isolate by phage-display several strong binders against the five proteins tested in this study, the Syk and Aurora-A protein kinases, the alphabeta tubulin dimer, the papillomavirus E6 protein and the core histones. Some of the selected scFvs are expressed at an exceptional high level in the bacterial cytoplasm, allowing the purification of 1 mg of active scFv from only 20 ml of culture. Finally, we show that after three rounds of selection against core histones, more than half of the selected scFvs were active when expressed in vivo in human cells since they were essentially localized in the nucleus. CONCLUSION This new library is a promising tool not only for an easy and large-scale selection of functional intrabodies but also for the isolation of highly expressed scFvs that could be used in numerous biotechnological and therapeutic applications.
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Affiliation(s)
- Pascal Philibert
- CNRS, UMR5160, CRLC, 15, av, Charles Flahault, BP14491, 34093, Montpellier Cedex 5, France.
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17
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A protein silencing switch by ligand-induced proteasome-targeting intrabodies. J Mol Biol 2007; 374:641-54. [PMID: 17950312 DOI: 10.1016/j.jmb.2007.09.053] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2007] [Revised: 09/14/2007] [Accepted: 09/18/2007] [Indexed: 11/24/2022]
Abstract
The selective knock-down of cellular proteins has proven useful for in vivo studies of protein function and RNAi methods are readily available for this purpose. However, interfering directly at the protein level may have distinct advantages, with the intracellular targeting of antibodies (intrabodies) representing an attractive option, although not a general one. We demonstrate a novel, general strategy named suicide (or silencing) intrabody technology (SIT), based on the inducible degradation of intrabodies, which are equipped with proteasome-targeting sequences and thus converted into suicide intrabodies. We show that suicide intrabodies are able to redirect the target cellular proteins upon stimulus administration to the proteolytic machinery, thus resulting in selective protein knock-down. Remarkably, suicide intrabody acts in a catalytic fashion. SIT is a ligand-inducible strategy, potentially applicable to any protein of interest and does not require the engineering of cellular proteolytic enzymes. SIT represents a general approach to confer "neutralizing" properties to any intrabody, a valuable feature, given the present impossibility to select a priori intrinsically neutralizing antibodies. This knock-down strategy, together with available methods to isolate functional intrabodies, should allow the large-scale investigation of intracellular protein networks.
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18
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Courtête J, Sibler AP, Zeder-Lutz G, Dalkara D, Oulad-Abdelghani M, Zuber G, Weiss E. Suppression of cervical carcinoma cell growth by intracytoplasmic codelivery of anti-oncoprotein E6 antibody and small interfering RNA. Mol Cancer Ther 2007; 6:1728-35. [PMID: 17575104 DOI: 10.1158/1535-7163.mct-06-0808] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cervical cancer is caused by high-risk types of human papillomaviruses (HPV) that encode the E6 and E7 oncogenes. Silencing of E6 gene expression in HPV-positive cell lines by transfection of small interfering RNA (siRNA) with cationic lipids restores the dormant p53 tumor suppressor pathway. Because cationic lipids can also be used for intracytoplasmic delivery of proteins, we tested whether the delivery of monoclonal antibodies that bind to HPV16 E6 and neutralize its biological activity in vitro could restore p53 function in tumor cells. Here, we show that the 4C6 antibody is efficiently delivered into the cell cytoplasm using a lipidic reagent used for siRNA transfection. The delivery of 4C6 resulted in the nuclear accumulation of p53 protein in CaSki and SiHa cells but not in HeLa cells. Furthermore, the antibody-mediated p53 response was dramatically increased when a peptide corresponding to the 4C6 epitope and bearing a COOH-terminal cysteine residue was added to the transduction mixture. We found that a fraction of the added peptides were dimers that allowed the formation of antibody polymers adsorbed onto the lipidic matrix. With this system, the proliferation of CaSki and SiHa cells was strongly diminished, but no apoptosis was detectable. Remarkably, cell growth was almost totally suppressed by the addition of E6-specific siRNA to the transduction complex. The results indicate that the activity of E6 oncoprotein can be down-regulated in vivo by lipid-mediated antibody delivery and that antibodies and siRNA act synergistically when codelivered. This novel targeting strategy is simple to implement and may find therapeutic applications.
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Affiliation(s)
- Jérôme Courtête
- Institut Gilbert-Laustriat, UMR 7175, ESBS, Illkirch Cedex, France
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Lagrange M, Boulade-Ladame C, Mailly L, Weiss E, Orfanoudakis G, Deryckere F. Intracellular scFvs against the viral E6 oncoprotein provoke apoptosis in human papillomavirus-positive cancer cells. Biochem Biophys Res Commun 2007; 361:487-92. [PMID: 17658466 DOI: 10.1016/j.bbrc.2007.07.040] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2007] [Accepted: 07/11/2007] [Indexed: 12/01/2022]
Abstract
The E6 protein of human papillomavirus type 16 (16E6) is involved in the tumorigenesis of human cervical cells by targeting numerous cellular proteins. We have designed a strategy for neutralizing 16E6 based on the intracellular expression of single-chain Fv antibodies (scFvs) specific to 16E6. Recombinant adenovirus vectors were constructed to allow expression of two 16E6-binding scFvs and one 16E6-non-binding scFv in HPV16-positive and -negative cells. Expression of the scFvs provoked two types of effects: (i) inhibition of proliferation of all cell lines tested, this aspecific toxicity being likely due to the aggregation of unfolded scFvs; and (ii) apoptosis observed only in HPV16-positive cervical cancer cell lines after expression of 16E6-binding scFvs, this specific effect being proportional to the intracellular solubility of the scFvs. These data demonstrate the feasibility of intracellular immunization with anti-16E6 scFvs and highlight the importance of the solubility of the intracellular antibodies.
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Affiliation(s)
- Magali Lagrange
- UMR 7175-LC1, CNRS, Université Louis Pasteur (Strasbourg I), ESBS, Boulevard Sébastien Brant, BP 10413, 67412 Illkirch Cedex, France
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20
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Characterization of antibodies in single-chain format against the E7 oncoprotein of the human papillomavirus type 16 and their improvement by mutagenesis. BMC Cancer 2007; 7:25. [PMID: 17266749 PMCID: PMC1797048 DOI: 10.1186/1471-2407-7-25] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2006] [Accepted: 01/31/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Human papillomaviruses (HPV) are the etiological agents of cervical cancer. The viral E7 protein plays a crucial role in viral oncogenesis. Many strategies have been explored to block the E7 oncoprotein activity. The single-chain variable antibody fragments (scFvs) are valuable tools in cancer immunotherapy and can be used as "intracellular antibodies" to knock out specific protein functions. For both in vivo and in vitro employment, the scFv intrinsic solubility and stability are important to achieve long-lasting effects. Here we report the characterization in terms of reactivity, solubility and thermal stability of three anti-HPV16 E7 scFvs. We have also analysed the scFv43 sequence with the aim of improving stability and then activity of the antibody, previously shown to have antiproliferative activity when expressed in HPV16-positive cells. METHODS The three anti-HPV16 E7 scFv 32, 43 51 were selected from the ETH-2 "phage-display" library. Thermal stability was evaluated with ELISA by determining the residual activity of each purified scFv against the recombinant HPV16 E7, after incubation in the presence of human seroalbumine for different time-intervals at different temperatures. Sequence analysis of the scFvs was performed with BLAST and CLUSTALL programs. The scFv43 aminoacid changes were reverted back to the consensus sequence from the immunoglobuline database by site-directed mutagenesis. ScFv solubility was evaluated with Western blotting by determining their relative amounts in the soluble and insoluble fractions of both prokaryotic and eukaryotic systems. RESULTS ScFv51 was the most thermally stable scFv considered. Sequence analysis of the most reactive scFv43 has evidenced 2 amino acid changes possibly involved in molecule stability, in the VH and VL CDR3 regions respectively. By mutagenesis, two novel scFv43-derived scFvs were obtained, scFv43 M1 and M2. ScFv43 M2 showed to have improved thermal stability and solubility in comparison with the parental scFv43. CONCLUSION The characterization of 5 specific anti-HPV16 E7 scFvs shows features important for their activity in vivo. ScFv43 M2 shows higher thermal stability with respect to the parental scFv43, and scFv51 shows high stability and solubility. These properties make the 2 scFvs the best candidates to be tested for anti-E7 activity in vivo.
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Abstract
We identified 1113 articles (103 reviews, 1010 primary research articles) published in 2005 that describe experiments performed using commercially available optical biosensors. While this number of publications is impressive, we find that the quality of the biosensor work in these articles is often pretty poor. It is a little disappointing that there appears to be only a small set of researchers who know how to properly perform, analyze, and present biosensor data. To help focus the field, we spotlight work published by 10 research groups that exemplify the quality of data one should expect to see from a biosensor experiment. Also, in an effort to raise awareness of the common problems in the biosensor field, we provide side-by-side examples of good and bad data sets from the 2005 literature.
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Affiliation(s)
- Rebecca L Rich
- Center for Biomolecular Interaction Analysis, University of Utah, Salt Lake City, UT 84132, USA
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