1
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Machin DC, Williamson DJ, Fisher P, Miller VJ, Arnott ZLP, Stevenson CME, Wildsmith GC, Ross JF, Wasson CW, Macdonald A, Andrews BI, Ungar D, Turnbull WB, Webb ME. Sortase-Modified Cholera Toxoids Show Specific Golgi Localization. Toxins (Basel) 2024; 16:194. [PMID: 38668619 PMCID: PMC11054894 DOI: 10.3390/toxins16040194] [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: 02/08/2024] [Revised: 03/18/2024] [Accepted: 04/09/2024] [Indexed: 04/29/2024] Open
Abstract
Cholera toxoid is an established tool for use in cellular tracing in neuroscience and cell biology. We use a sortase labeling approach to generate site-specific N-terminally modified variants of both the A2-B5 heterohexamer and B5 pentamer forms of the toxoid. Both forms of the toxoid are endocytosed by GM1-positive mammalian cells, and while the heterohexameric toxoid was principally localized in the ER, the B5 pentamer showed an unexpectedly specific localization in the medial/trans-Golgi. This study suggests a future role for specifically labeled cholera toxoids in live-cell imaging beyond their current applications in neuronal tracing and labeling of lipid rafts in fixed cells.
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Affiliation(s)
- Darren C. Machin
- School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK; (D.C.M.)
| | - Daniel J. Williamson
- School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK; (D.C.M.)
| | - Peter Fisher
- Department of Biology, University of York, York YO10 5DD, UK
| | | | - Zoe L. P. Arnott
- School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK; (D.C.M.)
| | - Charlotte M. E. Stevenson
- School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK; (D.C.M.)
| | - Gemma C. Wildsmith
- School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK; (D.C.M.)
| | - James F. Ross
- School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK; (D.C.M.)
| | - Christopher W. Wasson
- Faculty of Biological Sciences, Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK (A.M.)
| | - Andrew Macdonald
- Faculty of Biological Sciences, Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK (A.M.)
| | - Benjamin I. Andrews
- GlaxoSmithKline, Medicines Research Centre, Gunnels Wood Road, Stevenage SG1 2NY, UK
| | - Daniel Ungar
- Department of Biology, University of York, York YO10 5DD, UK
| | - W. Bruce Turnbull
- School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK; (D.C.M.)
| | - Michael E. Webb
- School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK; (D.C.M.)
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2
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Targeting the Inside of Cells with Biologicals: Toxin Routes in a Therapeutic Context. BioDrugs 2023; 37:181-203. [PMID: 36729328 PMCID: PMC9893211 DOI: 10.1007/s40259-023-00580-y] [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] [Accepted: 01/12/2023] [Indexed: 02/03/2023]
Abstract
Numerous toxins translocate to the cytosol in order to fulfil their function. This demonstrates the existence of routes for proteins from the extracellular space to the cytosol. Understanding these routes is relevant to multiple aspects related to therapeutic applications. These include the development of anti-toxin treatments, the potential use of toxins as shuttles for delivering macromolecular cargo to the cytosol or the use of drugs based on toxins. Compared with other strategies for delivery, such as chemicals as carriers for macromolecular delivery or physical methods like electroporation, toxin routes present paths into the cell that potentially cause less damage and can be specifically targeted. The efficiency of delivery via toxin routes is limited. However, low-delivery efficiencies can be entirely sufficient, if delivered cargoes possess an amplification effect or if very few molecules are sufficient for inducing the desired effects. This is known for example from RNA-based vaccines that have been developed during the coronavirus disease 2019 pandemic as well as for other approved RNA-based drugs, which elicited the desired effect despite their typically low delivery efficiencies. The different mechanisms by which toxins enter cells may have implications for their technological utility. We review the mechanistic principles of the translocation pathway of toxins from the extracellular space to the cytosol, the delivery efficiencies, and therapeutic strategies or applications that exploit toxin routes for intracellular delivery.
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3
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Carbohydrates: Binding Sites and Potential Drug Targets for Neural-Affecting Pathogens. ADVANCES IN NEUROBIOLOGY 2023; 29:449-477. [DOI: 10.1007/978-3-031-12390-0_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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4
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In-Depth Characterization of a Re-Engineered Cholera Toxin Manufacturing Process Using Growth-Decoupled Production in Escherichia coli. Toxins (Basel) 2022; 14:toxins14060396. [PMID: 35737057 PMCID: PMC9228256 DOI: 10.3390/toxins14060396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 05/24/2022] [Accepted: 05/31/2022] [Indexed: 12/10/2022] Open
Abstract
Non-toxic derivatives of the cholera toxin are extensively used in neuroscience, as neuronal tracers to reveal the location of cells in the central nervous system. They are, also, being developed as vaccine components and drug-delivery vehicles. Production of cholera-toxin derivatives is often non-reproducible; the quality and quantity require extensive fine-tuning to produce them in lab-scale settings. In our studies, we seek a resolution to this problem, by expanding the molecular toolbox of the Escherichia coli expression system with suitable production, purification, and offline analytics, to critically assess the quality of a probe or drug delivery, based on a non-toxic derivative of the cholera toxin. We present a re-engineered Cholera Toxin Complex (rCTC), wherein its toxic A1 domain was replaced with Maltose Binding Protein (MBP), as a model for an rCTC-based targeted-delivery vehicle. Here, we were able to improve the rCTC production by 11-fold (168 mg/L vs. 15 mg/L), in comparison to a host/vector combination that has been previously used (BL21(DE3) pTRBAB5-G1S). This 11-fold increase in the rCTC production capability was achieved by (1) substantial vector backbone modifications, (2) using Escherichia coli strains capable of growth-decoupling (V strains), (3) implementing a well-tuned fed-batch production protocol at a 1 L scale, and (4) testing the stability of the purified product. By an in-depth characterization of the production process, we revealed that secretion of rCTC across the E. coli Outer Membrane (OM) is processed by the Type II secretion-system general secretory pathway (gsp-operon) and that cholera toxin B-pentamerization is, likely, the rate-limiting step in complex formation. Upon successful manufacturing, we have validated the biological activity of rCTC, by measuring its binding affinity to its carbohydrate receptor GM1 oligosaccharide (Kd = 40 nM), or binding to Jurkat cells (93 pM) and delivering the cargo (MBP) in a retrograde fashion to the cell.
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5
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Tian S, Liu Y, Appleton E, Wang H, Church GM, Dong M. Targeted intracellular delivery of Cas13 and Cas9 nucleases using bacterial toxin-based platforms. Cell Rep 2022; 38:110476. [PMID: 35263584 PMCID: PMC8958846 DOI: 10.1016/j.celrep.2022.110476] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 12/26/2021] [Accepted: 02/11/2022] [Indexed: 02/06/2023] Open
Abstract
Targeted delivery of therapeutic proteins toward specific cells and across cell membranes remains major challenges. Here, we develop protein-based delivery systems utilizing detoxified single-chain bacterial toxins such as diphtheria toxin (DT) and botulinum neurotoxin (BoNT)-like toxin, BoNT/X, as carriers. The system can deliver large protein cargoes including Cas13a, CasRx, Cas9, and Cre recombinase into cells in a receptor-dependent manner, although delivery of ribonucleoproteins containing guide RNAs is not successful. Delivery of Cas13a and CasRx, together with guide RNA expression, reduces mRNAs encoding GFP, SARS-CoV-2 fragments, and endogenous proteins PPIB, KRAS, and CXCR4 in multiple cell lines. Delivery of Cre recombinase modifies the reporter loci in cells. Delivery of Cas9, together with guide RNA expression, generates mutations at the targeted genomic sites in cell lines and induced pluripotent stem cell (iPSC)-derived human neurons. These findings establish modular delivery systems based on single-chain bacterial toxins for delivery of membrane-impermeable therapeutics into targeted cells.
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Affiliation(s)
- Songhai Tian
- Department of Urology, Boston Children's Hospital, Boston, MA 02115, USA; Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, MA 02115, USA.
| | - Yang Liu
- Department of Urology, Boston Children's Hospital, Boston, MA 02115, USA; Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, MA 02115, USA; Department of Nephrology, The First Hospital of Jilin University, Changchun, 130021, China
| | - Evan Appleton
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA; Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, MA 02115, USA
| | - Huan Wang
- Department of Urology, Boston Children's Hospital, Boston, MA 02115, USA; Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, MA 02115, USA
| | - George M Church
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA; Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, MA 02115, USA
| | - Min Dong
- Department of Urology, Boston Children's Hospital, Boston, MA 02115, USA; Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, MA 02115, USA.
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6
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Haywood EE, Handy NB, Lopez JW, Ho M, Wilson BA. Insertion-trigger residues differentially modulate endosomal escape by cytotoxic necrotizing factor toxins. J Biol Chem 2021; 297:101347. [PMID: 34715130 PMCID: PMC8592880 DOI: 10.1016/j.jbc.2021.101347] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 10/13/2021] [Accepted: 10/18/2021] [Indexed: 01/20/2023] Open
Abstract
The cellular specificity, potency, and modular nature of bacterial protein toxins enable their application for targeted cytosolic delivery of therapeutic cargo. Efficient endosomal escape is a critical step in the design of bacterial toxin-inspired drug delivery (BTIDD) vehicles to avoid lysosomal degradation and promote optimal cargo delivery. The cytotoxic necrotizing factor (CNF) family of modular toxins represents a useful model for investigating cargo-delivery mechanisms due to the availability of many homologs with high sequence identity, their flexibility in swapping domains, and their differential activity profiles. Previously, we found that CNFy is more sensitive to endosomal acidification inhibitors than CNF1 and CNF2. Here, we report that CNF3 is even less sensitive than CNF1/2. We identified two amino acid residues within the putative translocation domain (E374 and E412 in CNFy, Q373 and S411 in CNF3) that differentiate between these two toxins. Swapping these corresponding residues in each toxin changed the sensitivity to endosomal acidification and efficiency of cargo-delivery to be more similar to the other toxin. Results suggested that trafficking to the more acidic late endosome is required for cargo delivery by CNFy but not CNF3. This model was supported by results from toxin treatment of cells in the presence of NH4Cl, which blocks endosomal acidification, and of small-molecule inhibitors EGA, which blocks trafficking to late endosomes, and ABMA, which blocks endosomal escape and trafficking to the lysosomal degradative pathway. These findings suggest that it is possible to fine-tune endosomal escape and cytosolic cargo delivery efficiency in designing BTIDD platforms.
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Affiliation(s)
- Elizabeth E Haywood
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Nicholas B Handy
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - James W Lopez
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Mengfei Ho
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Brenda A Wilson
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
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7
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Balmforth MR, Haigh J, Kumar V, Dai W, Tiede C, Tomlinson DC, Deuchars J, Webb ME, Turnbull WB. Piggybacking on the Cholera Toxin: Identification of a CTB-Binding Protein as an Approach for Targeted Delivery of Proteins to Motor Neurons. Bioconjug Chem 2021; 32:2205-2212. [PMID: 34565149 DOI: 10.1021/acs.bioconjchem.1c00373] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A significant unmet need exists for the delivery of biologic drugs such as polypeptides or nucleic acids to the central nervous system for the treatment and understanding of neurodegenerative diseases. Naturally occurring bacterial toxins have been considered as tools to meet this need. However, due to the complexity of tethering macromolecular drugs to toxins and the inherent dangers of working with large quantities of recombinant toxins, no such route has been successfully exploited. Developing a method where a bacterial toxin's nontoxic targeting subunit can be assembled with a drug immediately prior to in vivo administration has the potential to circumvent some of these issues. Using a phage-display screen, we identified two antibody mimetics, anticholera toxin Affimer (ACTA)-A2 and ACTA-C6 that noncovalently associate with the nonbinding face of the cholera toxin B-subunit. In a first step toward the development of a nonviral motor neuron drug-delivery vehicle, we show that Affimers can be selectively delivered to motor neurons in vivo.
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Affiliation(s)
- Matthew R Balmforth
- School of Chemistry, School of Biomedical Sciences and Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds LS2 9JT, U.K
| | - Jessica Haigh
- School of Chemistry, School of Biomedical Sciences and Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds LS2 9JT, U.K
| | - Vajinder Kumar
- School of Chemistry and Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds LS2 9JT, U.K.,Akal University, Talwandi Sabo, Punjab 151302, India
| | - Wenyue Dai
- School of Chemistry and Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds LS2 9JT, U.K
| | - Christian Tiede
- School of Molecular and Cellular Biology, and Astbury Centre for Structural and Molecular Biology, University of Leeds, Faculty of Biological Sciences, Leeds LS2 9JT, U.K
| | - Darren C Tomlinson
- School of Molecular and Cellular Biology, and Astbury Centre for Structural and Molecular Biology, University of Leeds, Faculty of Biological Sciences, Leeds LS2 9JT, U.K
| | - Jim Deuchars
- School of Biomedical Sciences, University of Leeds, Leeds LS2 9JT, U.K
| | - Michael E Webb
- School of Chemistry and Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds LS2 9JT, U.K
| | - W Bruce Turnbull
- School of Chemistry and Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds LS2 9JT, U.K
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8
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Miyashita SI, Zhang J, Zhang S, Shoemaker CB, Dong M. Delivery of single-domain antibodies into neurons using a chimeric toxin-based platform is therapeutic in mouse models of botulism. Sci Transl Med 2021; 13:13/575/eaaz4197. [PMID: 33408184 DOI: 10.1126/scitranslmed.aaz4197] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 05/01/2020] [Indexed: 12/15/2022]
Abstract
Efficient penetration of cell membranes and specific targeting of a cell type represent major challenges for developing therapeutics toward intracellular targets. One example facing these hurdles is to develop post-exposure treatment for botulinum neurotoxins (BoNTs), a group of bacterial toxins (BoNT/A to BoNT/G) that are major potential bioterrorism agents. BoNTs enter motor neurons, block neurotransmitter release, and cause a paralytic disease botulism. Members of BoNTs such as BoNT/A exhibit extremely long half-life within neurons, resulting in persistent paralysis for months, yet there are no therapeutics that can inhibit BoNTs once they enter neurons. Here, we developed a chimeric toxin-based delivery platform by fusing the receptor-binding domain of a BoNT, which targets neurons, with the membrane translocation domain and inactivated protease domain of the recently discovered BoNT-like toxin BoNT/X, which can deliver cargoes across endosomal membranes into the cytosol. A therapeutic protein was then created by fusing a single-domain antibody (nanobody) against BoNT/A with the delivery platform. In vitro characterization demonstrated that nanobodies were delivered into cultured neurons and neutralized BoNT/A in neurons. Administration of this protein in mice shortened duration of local muscle paralysis, restoring muscle function within hours, and rescued mice from systemic toxicity of lethal doses of BoNT/A. Fusion of two nanobodies, one against BoNT/A and the other against BoNT/B, created a multivalent therapeutic protein able to neutralize both BoNT/A and BoNT/B in mice. These studies provide an effective post-exposure treatment for botulism and establish a platform for intracellular delivery of therapeutics targeting cytosolic proteins and processes.
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Affiliation(s)
- Shin-Ichiro Miyashita
- Department of Urology, Boston Children's Hospital, Boston, MA 02115, USA.,Department of Surgery and Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA
| | - Jie Zhang
- Department of Urology, Boston Children's Hospital, Boston, MA 02115, USA.,Department of Surgery and Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA
| | - Sicai Zhang
- Department of Urology, Boston Children's Hospital, Boston, MA 02115, USA.,Department of Surgery and Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA
| | - Charles B Shoemaker
- Department of Infectious Diseases and Global Health, Cummings School of Veterinary Medicine at Tufts University, North Grafton, MA 01536, USA
| | - Min Dong
- Department of Urology, Boston Children's Hospital, Boston, MA 02115, USA. .,Department of Surgery and Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA
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9
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Cossette B, Kelly SH, Collier JH. Intranasal Subunit Vaccination Strategies Employing Nanomaterials and Biomaterials. ACS Biomater Sci Eng 2020; 7:1765-1779. [DOI: 10.1021/acsbiomaterials.0c01291] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Benjamin Cossette
- Department of Biomedical Engineering, Duke University, 101 Science Drive, Durham, North Carolina 27708, United States
| | - Sean H. Kelly
- Department of Biomedical Engineering, Duke University, 101 Science Drive, Durham, North Carolina 27708, United States
| | - Joel H. Collier
- Department of Biomedical Engineering, Duke University, 101 Science Drive, Durham, North Carolina 27708, United States
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10
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Tremblay JM, Vazquez-Cintron E, Lam KH, Mukherjee J, Bedenice D, Ondeck CA, Conroy MT, Bodt SML, Winner BM, Webb RP, Ichtchenko K, Jin R, McNutt PM, Shoemaker CB. Camelid VHH Antibodies that Neutralize Botulinum Neurotoxin Serotype E Intoxication or Protease Function. Toxins (Basel) 2020; 12:toxins12100611. [PMID: 32987745 PMCID: PMC7598594 DOI: 10.3390/toxins12100611] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 09/02/2020] [Accepted: 09/11/2020] [Indexed: 12/12/2022] Open
Abstract
Botulinum neurotoxin (BoNT) serotype E is one of three serotypes that cause the preponderance of human botulism cases and is a Tier 1 Select Agent. BoNT/E is unusual among BoNT serotypes for its rapid onset and short duration of intoxication. Here we report two large panels of unique, unrelated camelid single-domain antibodies (VHHs) that were selected for their ability to bind to BoNT/E holotoxin and/or to the BoNT/E light chain protease domain (LC/E). The 19 VHHs which bind to BoNT/E were characterized for their subunit specificity and 8 VHHs displayed the ability to neutralize BoNT/E intoxication of neurons. Heterodimer antitoxins consisting of two BoNT/E-neutralizing VHHs, including one heterodimer designed using structural information for simultaneous binding, were shown to protect mice against co-administered toxin challenges of up to 500 MIPLD50. The 22 unique VHHs which bind to LC/E were characterized for their binding properties and 9 displayed the ability to inhibit LC/E protease activity. Surprisingly, VHHs selected on plastic-coated LC/E were virtually unable to recognize soluble or captured LC/E while VHHs selected on captured LC/E were poorly able to recognize LC/E coated to a plastic surface. This panel of anti-LC/E VHHs offer insight into BoNT/E function, and some may have value as components of therapeutic antidotes that reverse paralysis following BoNT/E exposures.
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Affiliation(s)
- Jacqueline M. Tremblay
- Department of Infectious Disease and Global Health, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA 01536, USA; (J.M.T.); (J.M.)
| | - Edwin Vazquez-Cintron
- The United States Army Medical Research Institute of Chemical Defense, Fort Detrick, MD 21010, USA; (E.V.-C.); (C.A.O.); (M.T.C.); (S.M.L.B.); (B.M.W.); (P.M.M.)
| | - Kwok-Ho Lam
- Department of Physiology & Biophysics, University of California, Irvine, CA 92697-4560, USA; (K.-H.L.); (R.J.)
| | - Jean Mukherjee
- Department of Infectious Disease and Global Health, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA 01536, USA; (J.M.T.); (J.M.)
| | - Daniela Bedenice
- Department of Clinical Sciences, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA 01536, USA;
| | - Celinia A. Ondeck
- The United States Army Medical Research Institute of Chemical Defense, Fort Detrick, MD 21010, USA; (E.V.-C.); (C.A.O.); (M.T.C.); (S.M.L.B.); (B.M.W.); (P.M.M.)
| | - Matthieu T. Conroy
- The United States Army Medical Research Institute of Chemical Defense, Fort Detrick, MD 21010, USA; (E.V.-C.); (C.A.O.); (M.T.C.); (S.M.L.B.); (B.M.W.); (P.M.M.)
| | - Skylar M. L. Bodt
- The United States Army Medical Research Institute of Chemical Defense, Fort Detrick, MD 21010, USA; (E.V.-C.); (C.A.O.); (M.T.C.); (S.M.L.B.); (B.M.W.); (P.M.M.)
| | - Brittany M. Winner
- The United States Army Medical Research Institute of Chemical Defense, Fort Detrick, MD 21010, USA; (E.V.-C.); (C.A.O.); (M.T.C.); (S.M.L.B.); (B.M.W.); (P.M.M.)
| | - Robert P. Webb
- Bacteriology Division, U.S. Army Medical Research Institute of Infectious Diseases, Ft. Detrick, MD 21702-5011, USA;
| | - Konstantin Ichtchenko
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA;
| | - Rongsheng Jin
- Department of Physiology & Biophysics, University of California, Irvine, CA 92697-4560, USA; (K.-H.L.); (R.J.)
| | - Patrick M. McNutt
- The United States Army Medical Research Institute of Chemical Defense, Fort Detrick, MD 21010, USA; (E.V.-C.); (C.A.O.); (M.T.C.); (S.M.L.B.); (B.M.W.); (P.M.M.)
| | - Charles B. Shoemaker
- Department of Infectious Disease and Global Health, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA 01536, USA; (J.M.T.); (J.M.)
- Correspondence:
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11
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Heat-Stable Enterotoxins of Enterotoxigenic Escherichia coli and Their Impact on Host Immunity. Toxins (Basel) 2019; 11:toxins11010024. [PMID: 30626031 PMCID: PMC6356903 DOI: 10.3390/toxins11010024] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 12/31/2018] [Accepted: 01/03/2019] [Indexed: 01/12/2023] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) are an important diarrhea-causing pathogen and are regarded as a global threat for humans and farm animals. ETEC possess several virulence factors to infect its host, including colonization factors and enterotoxins. Production of heat-stable enterotoxins (STs) by most ETEC plays an essential role in triggering diarrhea and ETEC pathogenesis. In this review, we summarize the heat-stable enterotoxins of ETEC strains from different species as well as the molecular mechanisms used by these heat-stable enterotoxins to trigger diarrhea. As recently described, intestinal epithelial cells are important modulators of the intestinal immune system. Thus, we also discuss the impact of the heat-stable enterotoxins on this role of the intestinal epithelium and how these enterotoxins might affect intestinal immune cells. Finally, the latest developments in vaccination strategies to protect against infections with ST secreting ETEC strains are discussed. This review might inform and guide future research on heat-stable enterotoxins to further unravel their molecular pathogenesis, as well as to accelerate vaccine design.
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12
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Lichtenstein BR, Höcker B. Engineering an AB 5 Protein Carrier. Sci Rep 2018; 8:12643. [PMID: 30139944 PMCID: PMC6107655 DOI: 10.1038/s41598-018-30910-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 08/07/2018] [Indexed: 11/18/2022] Open
Abstract
The promise of biologic therapeutics is hindered by the challenge to deliver their activity to biochemically relevant sites within diseased cells. The favourable application of the natural protein carriers of the AB5 toxin family to this challenge has been restricted owing to still unresolved requirements for assembling non-native cargo into carrier complexes. Here, we clarify the properties of fusion peptides which allow co-assembly of a selected fluorescent protein cargo with the non-toxic B subunit of a heat-labile enterotoxin. We establish the influence of sequence length, sequence identity and secondary structure of these linking domains on the assembly and disassembly of the complexes. Through our engineering framework we identify several non-native, reduced length fusion sequences that robustly assemble with the native carriers, maintain their ability to deliver protein cargo to cells, and demonstrate substantially refined in vitro properties. Constructs based upon these sequences should prove directly applicable to a variety of protein delivery challenges, and the described design framework should find immediate application to other members of the AB5 protein carrier family.
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Affiliation(s)
- Bruce R Lichtenstein
- Max Planck Institute for Developmental Biology, 72076, Tübingen, Germany. .,Department of Biochemistry, University of Bayreuth, 95447, Bayreuth, Germany.
| | - Birte Höcker
- Max Planck Institute for Developmental Biology, 72076, Tübingen, Germany. .,Department of Biochemistry, University of Bayreuth, 95447, Bayreuth, Germany.
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13
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Ryou JH, Sohn YK, Hwang DE, Park WY, Kim N, Heo WD, Kim MY, Kim HS. Engineering of bacterial exotoxins for highly efficient and receptor-specific intracellular delivery of diverse cargos. Biotechnol Bioeng 2016; 113:1639-46. [PMID: 26773973 DOI: 10.1002/bit.25935] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 01/14/2016] [Indexed: 01/27/2023]
Abstract
The intracellular delivery of proteins with high efficiency in a receptor-specific manner is of great significance in molecular medicine and biotechnology, but remains a challenge. Herein, we present the development of a highly efficient and receptor-specific delivery platform for protein cargos by combining the receptor binding domain of Escherichia coli Shiga-like toxin and the translocation domain of Pseudomonas aeruginosa exotoxin A. We demonstrated the utility and efficiency of the delivery platform by showing a cytosolic delivery of diverse proteins both in vitro and in vivo in a receptor-specific manner. In particular, the delivery system was shown to be effective for targeting an intracellular protein and consequently suppressing the tumor growth in xenograft mice. The present platform can be widely used for intracellular delivery of diverse functional macromolecules with high efficiency in a receptor-specific manner. Biotechnol. Bioeng. 2016;113: 1639-1646. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Jeong-Hyun Ryou
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Korea
| | - Yoo-Kyoung Sohn
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Korea
| | - Da-Eun Hwang
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Korea
| | - Woo-Yong Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Korea
| | - Nury Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Korea
| | - Won-Do Heo
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Korea
| | - Mi-Young Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Korea
| | - Hak-Sung Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Korea.
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Ma Y. Recent advances in nontoxicEscherichia coliheat-labile toxin and its derivative adjuvants. Expert Rev Vaccines 2016; 15:1361-1371. [DOI: 10.1080/14760584.2016.1182868] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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15
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Zuverink M, Barbieri JT. From GFP to β-lactamase: advancing intact cell imaging for toxins and effectors. Pathog Dis 2015; 73:ftv097. [PMID: 26500183 DOI: 10.1093/femspd/ftv097] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2015] [Indexed: 11/13/2022] Open
Abstract
Canonical reporters such as green fluorescent protein (GFP) and luciferase have assisted researchers in probing cellular pathways and processes. Prior research in pathogenesis depended on sensitivity of biochemical and biophysical techniques to identify effectors and elucidate entry mechanisms. Recently, the β-lactamase (βlac) reporter system has advanced toxin and effector reporting by permitting measurement of βlac delivery into the cytosol or host βlac expression in intact cells. βlac measurement in cells was facilitated by the development of the fluorogenic substrate, CCF2-AM, to identify novel effectors, target cells, and domains involved in bacterial pathogenesis. The assay is also adaptable for high-throughput screening of small molecule inhibitors against toxins, providing information on mechanism and potential therapeutic agents. The versatility and limitations of the βlac reporter system as applied to toxins and effectors are discussed in this review.
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Affiliation(s)
- Madison Zuverink
- Medical College of Wisconsin, Microbiology and Molecular Genetics, Milwaukee, WI 53226, USA
| | - Joseph T Barbieri
- Medical College of Wisconsin, Microbiology and Molecular Genetics, Milwaukee, WI 53226, USA
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16
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Herrera C, Tremblay JM, Shoemaker CB, Mantis NJ. Mechanisms of Ricin Toxin Neutralization Revealed through Engineered Homodimeric and Heterodimeric Camelid Antibodies. J Biol Chem 2015; 290:27880-9. [PMID: 26396190 DOI: 10.1074/jbc.m115.658070] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Indexed: 11/06/2022] Open
Abstract
Novel antibody constructs consisting of two or more different camelid heavy-chain only antibodies (VHHs) joined via peptide linkers have proven to have potent toxin-neutralizing activity in vivo against Shiga, botulinum, Clostridium difficile, anthrax, and ricin toxins. However, the mechanisms by which these so-called bispecific VHH heterodimers promote toxin neutralization remain poorly understood. In the current study we produced a new collection of ricin-specific VHH heterodimers, as well as VHH homodimers, and characterized them for their ability neutralize ricin in vitro and in vivo. We demonstrate that the VHH heterodimers, but not homodimers were able to completely protect mice against ricin challenge, even though the two classes of antibodies (heterodimers and homodimers) had virtually identical affinities for ricin holotoxin and similar IC50 values in a Vero cell cytotoxicity assay. The VHH heterodimers did differ from the homodimers in their ability to promote toxin aggregation in solution, as revealed through analytical ultracentrifugation. Moreover, the VHH heterodimers that were most effective at promoting ricin aggregation in solution were also the most effective at blocking ricin attachment to cell surfaces. Collectively, these data suggest that heterodimeric VHH-based neutralizing agents may function through the formation of antibody-toxin complexes that are impaired in their ability to access host cell receptors.
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Affiliation(s)
- Cristina Herrera
- From the Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, New York 12208, the Department of Biomedical Sciences, University at Albany School of Public Health, Albany, New York 12201, and
| | - Jacqueline M Tremblay
- the Department of Infectious Disease and Global Health, Tufts Cummings School of Veterinary Medicine, North Grafton, Massachuetts 01536
| | - Charles B Shoemaker
- the Department of Infectious Disease and Global Health, Tufts Cummings School of Veterinary Medicine, North Grafton, Massachuetts 01536
| | - Nicholas J Mantis
- From the Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, New York 12208, the Department of Biomedical Sciences, University at Albany School of Public Health, Albany, New York 12201, and
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