1
|
Park SG, Lee HB, Kang S. Development of plug-and-deliverable intracellular protein delivery platforms based on botulinum neurotoxin. Int J Biol Macromol 2024; 261:129622. [PMID: 38266854 DOI: 10.1016/j.ijbiomac.2024.129622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 01/04/2024] [Accepted: 01/18/2024] [Indexed: 01/26/2024]
Abstract
Intracellular protein delivery systems have great potential in the fields of therapeutics development and biomedical research. However, targeted delivery, passing through the cell membrane without damaging the cells, and escaping from endosomal entrapment of endocytosed molecular cargos are major challenges of the system. Here, we present a novel intracellular protein delivery system based on modularly engineered botulinum neurotoxin type A (BoNT/A). LHNA domain, consisting of light chain and endosomal escape machinery of BoNT/A, was genetically fused with SpyCatcher (SC) and EGFR targeting affibody (EGFRAfb) to create SC-LHNA-EGFRAfb, a target-specific and protein cargo-switchable BoNT/A-based intracellular protein delivery platform. SC-LHNA-EGFRAfb was purely purified in large quantities, efficiently ligated with multiple ST-fused protein cargos individually, generating a variety of protein cargo-containing intracellular delivery complexes, and successfully delivered ligated protein cargos into the cytosol of target cells via receptor-mediated endocytosis, followed by endosomal escape and subsequent cytosolic delivery. SC-LHNA-EGFRAfb enhanced intracellular delivery efficiency of protein toxin, gelonin, by approximately 100-fold, highlighting the crucial roles of EGFRAfb and LHNA domain as a targeting ligand and an endosomal escape machinery, respectively, in the delivery process. The BoNT-based plug-and-deliverable intracellular protein delivery system has the potential to expand its applications in protein therapeutics and manipulating cellular processes.
Collapse
Affiliation(s)
- Seong Guk Park
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Hyun Bin Lee
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Sebyung Kang
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea.
| |
Collapse
|
2
|
Chan A, Tsourkas A. Intracellular Protein Delivery: Approaches, Challenges, and Clinical Applications. BME FRONTIERS 2024; 5:0035. [PMID: 38282957 PMCID: PMC10809898 DOI: 10.34133/bmef.0035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 12/14/2023] [Indexed: 01/30/2024] Open
Abstract
Protein biologics are powerful therapeutic agents with diverse inhibitory and enzymatic functions. However, their clinical use has been limited to extracellular applications due to their inability to cross plasma membranes. Overcoming this physiological barrier would unlock the potential of protein drugs for the treatment of many intractable diseases. In this review, we highlight progress made toward achieving cytosolic delivery of recombinant proteins. We start by first considering intracellular protein delivery as a drug modality compared to existing Food and Drug Administration-approved drug modalities. Then, we summarize strategies that have been reported to achieve protein internalization. These techniques can be broadly classified into 3 categories: physical methods, direct protein engineering, and nanocarrier-mediated delivery. Finally, we highlight existing challenges for cytosolic protein delivery and offer an outlook for future advances.
Collapse
Affiliation(s)
| | - Andrew Tsourkas
- Department of Bioengineering,
University of Pennsylvania, Philadelphia, PA, USA
| |
Collapse
|
3
|
di Leandro L, Colasante M, Pitari G, Ippoliti R. Hosts and Heterologous Expression Strategies of Recombinant Toxins for Therapeutic Purposes. Toxins (Basel) 2023; 15:699. [PMID: 38133203 PMCID: PMC10748335 DOI: 10.3390/toxins15120699] [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: 11/15/2023] [Revised: 12/05/2023] [Accepted: 12/07/2023] [Indexed: 12/23/2023] Open
Abstract
The production of therapeutic recombinant toxins requires careful host cell selection. Bacteria, yeast, and mammalian cells are common choices, but no universal solution exists. Achieving the delicate balance in toxin production is crucial due to potential self-intoxication. Recombinant toxins from various sources find applications in antimicrobials, biotechnology, cancer drugs, and vaccines. "Toxin-based therapy" targets diseased cells using three strategies. Targeted cancer therapy, like antibody-toxin conjugates, fusion toxins, or "suicide gene therapy", can selectively eliminate cancer cells, leaving healthy cells unharmed. Notable toxins from various biological sources may be used as full-length toxins, as plant (saporin) or animal (melittin) toxins, or as isolated domains that are typical of bacterial toxins, including Pseudomonas Exotoxin A (PE) and diphtheria toxin (DT). This paper outlines toxin expression methods and system advantages and disadvantages, emphasizing host cell selection's critical role.
Collapse
Affiliation(s)
| | | | | | - Rodolfo Ippoliti
- Department of Life, Health and Environmental Sciences, University of L’Aquila, 67100 L’Aquila, Italy; (L.d.L.); (M.C.); (G.P.)
| |
Collapse
|
4
|
Heber S, Borho J, Stadler N, Wondany F, König I, Michaelis J, Papatheodorou P, Barth H, Fellermann M. The Clostridium botulinum C2 Toxin Subunit C2IIa Delivers Enzymes with Positively Charged N-Termini into the Cytosol of Target Cells. Toxins (Basel) 2023; 15:390. [PMID: 37368691 DOI: 10.3390/toxins15060390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 06/05/2023] [Accepted: 06/07/2023] [Indexed: 06/29/2023] Open
Abstract
The binary Clostridium (C.) botulinum C2 toxin consists of two non-linked proteins. The proteolytically activated binding/transport subunit C2IIa forms barrel-shaped homoheptamers, which bind to cell surface receptors, mediate endocytosis, and translocate the enzyme subunit C2I into the cytosol of target cells. Here, we investigate whether C2IIa can be harnessed as a transporter for proteins/enzymes fused to polycationic tags, as earlier demonstrated for the related anthrax toxin transport subunit PA63. To test C2IIa-mediated transport in cultured cells, reporter enzymes are generated by fusing different polycationic tags to the N- or C-terminus of other bacterial toxins' catalytic A subunits. C2IIa as well as PA63 deliver N-terminally polyhistidine-tagged proteins more efficiently compared to C-terminally tagged ones. However, in contrast to PA63, C2IIa does not efficiently deliver polylysine-tagged proteins into the cytosol of target cells. Moreover, untagged enzymes with a native cationic N-terminus are efficiently transported by both C2IIa and PA63. In conclusion, the C2IIa-transporter serves as a transport system for enzymes that harbor positively charged amino acids at their N-terminus. The charge distribution at the N-terminus of cargo proteins and their ability to unfold in the endosome and subsequently refold in the cytosol determine transport feasibility and efficiency.
Collapse
Affiliation(s)
- Sebastian Heber
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, Ulm University Medical Center, 89081 Ulm, Germany
| | - Joscha Borho
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, Ulm University Medical Center, 89081 Ulm, Germany
| | - Nicole Stadler
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, Ulm University Medical Center, 89081 Ulm, Germany
| | - Fanny Wondany
- Institute of Biophysics, Ulm University, 89081 Ulm, Germany
| | - Irina König
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, Ulm University Medical Center, 89081 Ulm, Germany
| | - Jens Michaelis
- Institute of Biophysics, Ulm University, 89081 Ulm, Germany
| | - Panagiotis Papatheodorou
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, Ulm University Medical Center, 89081 Ulm, Germany
| | - Holger Barth
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, Ulm University Medical Center, 89081 Ulm, Germany
| | - Maximilian Fellermann
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, Ulm University Medical Center, 89081 Ulm, Germany
| |
Collapse
|
5
|
Becker L, Plückthun A. DARPins bind their cytosolic targets after having been translocated through the protective antigen pore of anthrax toxin. Sci Rep 2023; 13:8048. [PMID: 37198284 DOI: 10.1038/s41598-023-34647-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 05/04/2023] [Indexed: 05/19/2023] Open
Abstract
Intracellular protein-protein interactions in aberrant signaling pathways have emerged as a prime target in several diseases, particularly cancer. Since many protein-protein interactions are mediated by rather flat surfaces, they can typically not be interrupted by small molecules as they require cavities for binding. Therefore, protein drugs might be developed to compete with undesired interactions. However, proteins in general are not able to translocate from the extracellular side to the cytosolic target site by themselves, and thus an efficient protein translocation system, ideally combining efficient translocation with receptor specificity, is in high demand. Anthrax toxin, the tripartite holotoxin of Bacillus anthracis, is one of the best studied bacterial protein toxins and has proven to be a suitable candidate for cell-specific translocation of cargoes in vitro and in vivo. Our group recently developed a retargeted protective antigen (PA) variant fused to different Designed Ankyrin Repeat Proteins (DARPins) to achieve receptor specificity, and we incorporated a receptor domain to stabilize the prepore and prevent cell lysis. This strategy had been shown to deliver high amounts of cargo DARPins fused behind the N-terminal 254 amino acids of Lethal Factor (LFN). Here, we established a cytosolic binding assay, demonstrating the ability of DARPins to refold in the cytosol and bind their target after been translocated by PA.
Collapse
Affiliation(s)
- Lukas Becker
- Department of Biochemistry, University of Zurich, Winterthurerstr. 190, 8057, Zurich, Switzerland
| | - Andreas Plückthun
- Department of Biochemistry, University of Zurich, Winterthurerstr. 190, 8057, Zurich, Switzerland.
| |
Collapse
|
6
|
Liu D, Zhan Y, Wu X, Qiao H, Zhang Y, Li B. Design, preparation and characterization of octopus-like self-releasing intracellular protein transporter LEB5 based on Escherichia coli heat-labile enterotoxin. Int J Biol Macromol 2023; 237:124172. [PMID: 36966860 DOI: 10.1016/j.ijbiomac.2023.124172] [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: 11/07/2022] [Revised: 03/16/2023] [Accepted: 03/21/2023] [Indexed: 04/03/2023]
Abstract
Despite the great potential of protein drugs as intracellular therapeutic agents, the unmet challenge in breaking through the cell membrane barrier and delivering them to intracellular targets remains. Therefore, developing safe and effective delivery vehicles is critical for fundamental biomedical research and clinical applications. In this study, we designed an octopus-like self-releasing intracellular protein transporter, the LEB5, based on the heat-labile enterotoxin. This carrier comprises five identical units, each of which has three main components: a linker, a self-releasing enzyme sensitivity loop, and the LTB transport domain. The LEB5 comprises five purified monomers that self-assemble to create a pentamer with ganglioside GM1 binding capacity. The fluorescent protein EGFP was used as a reporter system to identify the LEB5 features. The high-purity fusion protein ELEB monomer was produced from modified bacteria carrying pET24a(+)-eleb recombinant plasmids. EGFP protein could effectively detach from LEB5 by low dosage trypsin, according to electrophoresis analysis. The transmission electron microscopy results indicate that both LEB5 and ELEB5 pentamers exhibit a relatively regularly spherical shape, and the differential scanning calorimetry measurements further suggest that these proteins possess excellent thermal stability. Fluorescence microscopy revealed that LEB5 translocated EGFP into different cell types. Flow cytometry showed cellular differences in the transport capacity of LEB5. According to the confocal microscopy, fluorescence analysis and western blotting data, EGFP was transferred to the endoplasmic reticulum by the LEB5 carrier, detached from LEB5 by cleavage of the enzyme-sensitive loop, and released into the cytoplasm. Within the dosage range of LEB5 10-80 μg/mL, cell counting kit-8 assay revealed no significant changes in cell viability. These results demonstrated that LEB5 is a safe and effective intracellular self-releasing delivery vehicle capable of transporting and releasing protein medicines into cells.
Collapse
Affiliation(s)
- Di Liu
- College of Biological Sciences and Technology and Center for Veterinary Medicine, Taiyuan Normal University, Jinzhong 030619, Shanxi, China.
| | - Yafen Zhan
- College of Biological Sciences and Technology and Center for Veterinary Medicine, Taiyuan Normal University, Jinzhong 030619, Shanxi, China
| | - Xiaoying Wu
- College of Biological Sciences and Technology and Center for Veterinary Medicine, Taiyuan Normal University, Jinzhong 030619, Shanxi, China
| | - Hongping Qiao
- College of Biological Sciences and Technology and Center for Veterinary Medicine, Taiyuan Normal University, Jinzhong 030619, Shanxi, China
| | - Yeli Zhang
- College of Biological Sciences and Technology and Center for Veterinary Medicine, Taiyuan Normal University, Jinzhong 030619, Shanxi, China
| | - Bo Li
- College of Biological Sciences and Technology and Center for Veterinary Medicine, Taiyuan Normal University, Jinzhong 030619, Shanxi, China; School of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, Shanxi, China.
| |
Collapse
|
7
|
Roshan R, Naderi S, Behdani M, Ahangari Cohan R, Kazemi-Lomedasht F. A Novel Immunotoxin Targeting Epithelial Cell Adhesion Molecule Using Single Domain Antibody Fused to Diphtheria Toxin. Mol Biotechnol 2023; 65:637-644. [PMID: 36129635 DOI: 10.1007/s12033-022-00565-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 09/07/2022] [Indexed: 11/28/2022]
Abstract
Epithelial Cell Adhesion Molecule (EpCAM) is overexpressed in a variety of cancers such as colon, stomach, pancreas, and prostate adenocarcinomas. Inhibition of EpCAM is considered as a potential target for cancer therapy. In current study, anti-EpCAM immunotoxin (α-EpCAM IT) was developed using genetic fusion of α-EpCAM single domain antibody (nanobody) (α-EpCAM Nb) to truncated form of diphtheria toxin. The expression of recombinant α-EpCAM IT was induced by Isopropyl β-d-1-thiogalactopyranoside (IPTG) and confirmed by SDS-PAGE and western blot. Recombinant α-EpCAM IT was purified from the inclusion bodies and refolded using urea gradient procedure. The cytotoxicity and apoptosis activity of α-EpCAM IT on EpCAM over-expressing (MCF7), low-expressing (HEK293), and no-expressing (HUVEC) cells were evaluated by 3-4,5-Dimethylthiazol-2-yl (MTT) assay and annexin V-FITC-PI assay as well. In addition, anti-tumor activity of α-EpCAM IT was evaluated on nude mice bearing MCF7 tumor cells. Results showed success expression and purification of α-EpCAM IT. The α-EpCAM IT showed time and dose-dependent anti-proliferative activity on MCF-7 cells. However, α-EpCAM IT did not show any anti-proliferative activity on HEK293 and HUVEC cells as well. In addition, the annexin V-FITC-PI assay results showed that α-EpCAM IT significantly increased apoptotic rate in MCF-7 cells with no effect on HEK293 and HUVEC as well. Moreover, α-EpCAM IT significantly reduced tumor size in vivo study. The achieved results indicate the potential of designing α-EpCAM IT as a novel therapeutic for cancer therapy.
Collapse
Affiliation(s)
- Reyhaneh Roshan
- Venom and Biotherapeutics Molecules Laboratory, Biotechnology Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Shamsi Naderi
- Venom and Biotherapeutics Molecules Laboratory, Biotechnology Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Mahdi Behdani
- Venom and Biotherapeutics Molecules Laboratory, Biotechnology Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Reza Ahangari Cohan
- Department of Nanobiotechnology, New Technologies Research Group, Pasteur Institute of Iran, Tehran, Iran.
| | - Fatemeh Kazemi-Lomedasht
- Venom and Biotherapeutics Molecules Laboratory, Biotechnology Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran.
| |
Collapse
|
8
|
Clostridium botulinum C3 Toxin for Selective Delivery of Cargo into Dendritic Cells and Macrophages. Toxins (Basel) 2022; 14:toxins14100711. [DOI: 10.3390/toxins14100711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/13/2022] [Accepted: 10/14/2022] [Indexed: 11/16/2022] Open
Abstract
The protein toxin C3bot from Clostridium botulinum is a mono-ADP-ribosyltransferase that selectively intoxicates monocyte-derived cells such as macrophages, osteoclasts, and dendritic cells (DCs) by cytosolic modification of Rho-A, -B, and -C. Here, we investigated the application of C3bot as well as its non-toxic variant C3botE174Q as transporters for selective delivery of cargo molecules into macrophages and DCs. C3bot and C3botE174Q facilitated the uptake of eGFP into early endosomes of human-monocyte-derived macrophages, as revealed by stimulated emission depletion (STED) super-resolution microscopy. The fusion of the cargo model peptide eGFP neither affected the cell-type selectivity (enhanced uptake into human macrophages ex vivo compared to lymphocytes) nor the cytosolic release of C3bot. Moreover, by cell fractionation, we demonstrated that C3bot and C3botE174Q strongly enhanced the cytosolic release of functional eGFP. Subsequently, a modular system was created on the basis of C3botE174Q for covalent linkage of cargos via thiol–maleimide click chemistry. The functionality of this system was proven by loading small molecule fluorophores or an established reporter enzyme and investigating the cellular uptake and cytosolic release of cargo. Taken together, non-toxic C3botE174Q is a promising candidate for the cell-type-selective delivery of small molecules, peptides, and proteins into the cytosol of macrophages and DCs.
Collapse
|
9
|
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.
Collapse
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.
| |
Collapse
|
10
|
Ding GB, Zhu C, Wang Q, Cao H, Li BC, Yang P, Stauber RH, Nie G, Li Z. Molecularly engineered tumor acidity-responsive plant toxin gelonin for safe and efficient cancer therapy. Bioact Mater 2022; 18:42-55. [PMID: 35387163 PMCID: PMC8961304 DOI: 10.1016/j.bioactmat.2022.02.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 01/17/2022] [Accepted: 02/07/2022] [Indexed: 12/11/2022] Open
Abstract
Due to the unsatisfactory therapeutic efficacy and inexorable side effects of small molecule antineoplastic agents, extensive efforts have been devoted to the development of more potent macromolecular agents with high specificity. Gelonin is a plant-derived protein toxin that exhibits robust antitumor effect via inactivating ribosomes and inhibiting protein synthesis. Nonetheless, its poor internalization ability to tumor cells has compromised the therapeutic promise of gelonin. In this study, a tumor acidity-responsive intracellular protein delivery system ─ functional gelonin (Trx-pHLIP-Gelonin, TpG) composed of a thioredoxin (Trx) tag, a pH low insertion peptide (pHLIP) and gelonin, was designed and obtained by genetic recombination technique for the first time. TpG could effectively enter into tumor cells under weakly acidic conditions and markedly suppress tumor cell proliferation via triggering cell apoptosis and inhibiting protein synthesis. Most importantly, treatment by intravenous injection into subcutaneous SKOV3 solid tumors in a mouse model showed that TpG was much more effective than gelonin in curtailing tumor growth rates with negligible toxicity. Collectively, our present work suggests that the tumor acidity-targeted delivery manner endowed by pHLIP offers a new avenue for efficient delivery of other bioactive substances to acidic diseased tissues. A pH-responsive gelonin delivery platform — TpG was molecularly engineered. TpG exhibited good thermal stability and excellent serum stability. TpG enabled an efficient intracellular translocation of gelonin at pH 6.5. TpG exerted pronounced anti-proliferative effect via inducing massive apoptosis. TpG significantly delayed tumor growth with favorable in vivo biosafety profile.
Collapse
|
11
|
Sahni A, Pei D. Bacterial Toxins Escape the Endosome by Inducing Vesicle Budding and Collapse. ACS Chem Biol 2021; 16:2415-2422. [PMID: 34553899 DOI: 10.1021/acschembio.1c00540] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Bacterial protein toxins autonomously enter the cytosol of the target cell where they modify the activities of host components to exert their toxic effects. Many of the toxins enter the host cell by endocytosis followed by endosomal escape. However, their mechanism of endosomal escape remains unresolved. We show herein that diphtheria toxin (DT) and NleC of enteropathogenic Escherichia coli exit the endosome by inducing budding and collapse of small toxin-enriched vesicles from the endosomal membrane.
Collapse
Affiliation(s)
- Ashweta Sahni
- Department of Chemistry and Biochemistry and Ohio State Biochemistry Program, The Ohio State University, 484 West 12th Avenue, Columbus, Ohio 43210, United States
| | - Dehua Pei
- Department of Chemistry and Biochemistry and Ohio State Biochemistry Program, The Ohio State University, 484 West 12th Avenue, Columbus, Ohio 43210, United States
| |
Collapse
|
12
|
Hirschenberger M, Stadler N, Fellermann M, Sparrer KMJ, Kirchhoff F, Barth H, Papatheodorou P. CRISPA: A Non-viral, Transient Cas9 Delivery System Based on Reengineered Anthrax Toxin. Front Pharmacol 2021; 12:770283. [PMID: 34733166 PMCID: PMC8558532 DOI: 10.3389/fphar.2021.770283] [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: 09/03/2021] [Accepted: 10/01/2021] [Indexed: 11/13/2022] Open
Abstract
Translating the CRISPR/Cas9 genome editing technology into clinics is still hampered by rather unspecific, unsafe and/or inconvenient approaches for the delivery of its main components - the Cas9 endonuclease and a guide RNA - into cells. Here, we describe the development of a novel transient and non-viral Cas9 delivery strategy based on the translocation machinery of the Bacillus anthracis anthrax toxin, PA (protective antigen). We show that Cas9 variants fused to the N-terminus of the lethal factor or to a hexahistidine tag are shuttled through channels formed by PA into the cytosol of human cells. As proof-of-principle, we applied our new approach, denoted as CRISPA, to knock out lipolysis-stimulated lipoprotein receptor (LSR) in the human colon cancer cell line HCT116 and green-fluorescent protein (GFP) in human embryonic kidney 293T cells stably expressing GFP. Notably, we confirmed that the transporter PA can be adapted to recognize specific host cell-surface receptor proteins and may be optimized for cell type-selective delivery of Cas9. Altogether, CRISPA provides a novel, transient and non-viral way to deliver Cas9 into specific cells. Thus, this system is an additional step towards safe translation of the CRISPR/Cas9 technology into clinics.
Collapse
Affiliation(s)
- Maximilian Hirschenberger
- Institute of Pharmacology and Toxicology, Ulm University Medical Center, Ulm, Germany.,Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Nicole Stadler
- Institute of Pharmacology and Toxicology, Ulm University Medical Center, Ulm, Germany
| | - Maximilian Fellermann
- Institute of Pharmacology and Toxicology, Ulm University Medical Center, Ulm, Germany
| | | | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Holger Barth
- Institute of Pharmacology and Toxicology, Ulm University Medical Center, Ulm, Germany
| | | |
Collapse
|
13
|
Becker L, Singh Badwal J, Brandl F, Verdurmen WPR, Plückthun A. Thermodynamic Stability Is a Strong Predictor for the Delivery of DARPins to the Cytosol via Anthrax Toxin. Pharmaceutics 2021; 13:pharmaceutics13081285. [PMID: 34452246 PMCID: PMC8401532 DOI: 10.3390/pharmaceutics13081285] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 08/05/2021] [Indexed: 11/16/2022] Open
Abstract
Anthrax toxin has evolved to translocate its toxic cargo proteins to the cytosol of cells carrying its cognate receptor. Cargo molecules need to unfold to penetrate the narrow pore formed by its membrane-spanning subunit, protective antigen (PA). Various alternative cargo molecules have previously been tested, with some showing only limited translocation efficiency, and it may be assumed that these were too stable to be unfolded before passing through the anthrax pore. In this study, we systematically and quantitatively analyzed the correlation between the translocation of various designed ankyrin repeat proteins (DARPins) and their different sizes and thermodynamic stabilities. To measure cytosolic uptake, we used biotinylation of the cargo by cytosolic BirA, and we measured cargo equilibrium stability via denaturant-induced unfolding, monitored by circular dichroism (CD). Most of the tested DARPin cargoes, including target-binding ones, were translocated to the cytosol. Those DARPins, which remained trapped in the endosome, were confirmed by CD to show a high equilibrium stability. We could pinpoint a stability threshold up to which cargo DARPins still get translocated to the cytosol. These experiments have outlined the requirements for translocatable binding proteins, relevant stability measurements to assess translocatable candidates, and guidelines to further engineer this property if needed.
Collapse
Affiliation(s)
- Lukas Becker
- Department of Biochemistry, University of Zurich, Winterthurerstr. 190, 8057 Zurich, Switzerland; (L.B.); (J.S.B.); (F.B.)
| | - Jasleen Singh Badwal
- Department of Biochemistry, University of Zurich, Winterthurerstr. 190, 8057 Zurich, Switzerland; (L.B.); (J.S.B.); (F.B.)
| | - Fabian Brandl
- Department of Biochemistry, University of Zurich, Winterthurerstr. 190, 8057 Zurich, Switzerland; (L.B.); (J.S.B.); (F.B.)
| | - Wouter P. R. Verdurmen
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Medical Center, Geert Grooteplein 28, 6525 GA Nijmegen, The Netherlands;
| | - Andreas Plückthun
- Department of Biochemistry, University of Zurich, Winterthurerstr. 190, 8057 Zurich, Switzerland; (L.B.); (J.S.B.); (F.B.)
- Correspondence:
| |
Collapse
|
14
|
Abstract
The natural world has provided a host of materials and inspiration for the field of nanomedicine. By taking design cues from naturally occurring systems, the nanoengineering of advanced biomimetic platforms has significantly accelerated over the past decade. In particular, the biomimicry of bacteria, with their motility, taxis, immunomodulation, and overall dynamic host interactions, has elicited substantial interest and opened up exciting avenues of research. More recently, advancements in genetic engineering have given way to more complex and elegant systems with tunable control characteristics. Furthermore, bacterial derivatives such as membrane ghosts, extracellular vesicles, spores, and toxins have proven advantageous for use in nanotherapeutic applications, as they preserve many of the features from the original bacteria while also offering distinct advantages. Overall, bacteria-inspired nanomedicines can be employed in a range of therapeutic settings, from payload delivery to immunotherapy, and have proven successful in combatting both cancer and infectious disease.
Collapse
Affiliation(s)
- Maya Holay
- Department of NanoEngineering, Chemical Engineering Program, and Moores Cancer Center, University of California San Diego, La Jolla, CA 92093, USA
| | - Zhongyuan Guo
- Department of NanoEngineering, Chemical Engineering Program, and Moores Cancer Center, University of California San Diego, La Jolla, CA 92093, USA
| | - Jessica Pihl
- Department of NanoEngineering, Chemical Engineering Program, and Moores Cancer Center, University of California San Diego, La Jolla, CA 92093, USA
| | - Jiyoung Heo
- Department of NanoEngineering, Chemical Engineering Program, and Moores Cancer Center, University of California San Diego, La Jolla, CA 92093, USA
| | - Joon Ho Park
- Department of NanoEngineering, Chemical Engineering Program, and Moores Cancer Center, University of California San Diego, La Jolla, CA 92093, USA
| | - Ronnie H. Fang
- Department of NanoEngineering, Chemical Engineering Program, and Moores Cancer Center, University of California San Diego, La Jolla, CA 92093, USA
| | - Liangfang Zhang
- Department of NanoEngineering, Chemical Engineering Program, and Moores Cancer Center, University of California San Diego, La Jolla, CA 92093, USA
| |
Collapse
|
15
|
Dashtiahangar M, Rahbarnia L, Farajnia S, Salmaninejad A, Shabgah AG, Ghasemali S. Anti-cancer Immunotoxins, Challenges, and Approaches. Curr Pharm Des 2021; 27:932-941. [PMID: 33023437 DOI: 10.2174/1381612826666201006155346] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 08/07/2020] [Indexed: 11/22/2022]
Abstract
The development of recombinant immunotoxins (RITs) as a novel therapeutic strategy has made a revolution in the treatment of cancer. RITs result from the fusion of antibodies to toxin proteins for targeting and eliminating cancerous cells by inhibiting protein synthesis. Despite indisputable outcomes of RITs regarding inhibition of multiple cancer types, high immunogenicity has been known as the main obstacle in the clinical use of RITs. Various strategies have been proposed to overcome these limitations, including immunosuppressive therapy, humanization of the antibody fragment moiety, generation of immunotoxins originated from endogenous human cytotoxic enzymes, and modification of the toxin moiety to escape the immune system. This paper is devoted to review recent advances in the design of immunotoxins with lower immunogenicity.
Collapse
Affiliation(s)
- Maryam Dashtiahangar
- Department of Biology, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Leila Rahbarnia
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Safar Farajnia
- Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Arezoo Gowhari Shabgah
- Department of Immunology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Samaneh Ghasemali
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| |
Collapse
|
16
|
Torres C, Dumas S, Palacio-Castañeda V, Descroix S, Brock R, Verdurmen WPR. A Computational Investigation of In Vivo Cytosolic Protein Delivery for Cancer Therapy. Pharmaceutics 2021; 13:pharmaceutics13040562. [PMID: 33921165 PMCID: PMC8071550 DOI: 10.3390/pharmaceutics13040562] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 04/02/2021] [Accepted: 04/06/2021] [Indexed: 12/14/2022] Open
Abstract
The ability to specifically block or degrade cytosolic targets using therapeutic proteins would bring tremendous therapeutic opportunities in cancer therapy. Over the last few years, significant progress has been made with respect to tissue targeting, cytosolic delivery, and catalytic inactivation of targets, placing this aim within reach. Here, we developed a mathematical model specifically built for the evaluation of approaches towards cytosolic protein delivery, involving all steps from systemic administration to translocation into the cytosol and target engagement. Focusing on solid cancer tissues, we utilized the model to investigate the effects of microvascular permeability, receptor affinity, the cellular density of targeted receptors, as well as the mode of activity (blocking/degradation) on therapeutic potential. Our analyses provide guidance for the rational optimization of protein design for enhanced activity and highlight the importance of tuning the receptor affinity as a function of receptor density as well as the receptor internalization rate. Furthermore, we provide quantitative insights into how enzymatic cargoes can enhance the distribution, extent, and duration of therapeutic activity, already at very low catalytic rates. Our results illustrate that with current protein engineering approaches, the goal of delivery of cytosolic delivery of proteins for therapeutic effects is well within reach.
Collapse
Affiliation(s)
- Camilo Torres
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Medical Center, Geert Grooteplein 28, 6525 GA Nijmegen, The Netherlands; (C.T.); (V.P.-C.); (R.B.)
| | - Simon Dumas
- Physico-Chemistry Curie, Institut Curie, PSL Research University, CNRS UMR168, Sorbonne University, 75005 Paris, France; (S.D.); (S.D.)
| | - Valentina Palacio-Castañeda
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Medical Center, Geert Grooteplein 28, 6525 GA Nijmegen, The Netherlands; (C.T.); (V.P.-C.); (R.B.)
| | - Stéphanie Descroix
- Physico-Chemistry Curie, Institut Curie, PSL Research University, CNRS UMR168, Sorbonne University, 75005 Paris, France; (S.D.); (S.D.)
| | - Roland Brock
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Medical Center, Geert Grooteplein 28, 6525 GA Nijmegen, The Netherlands; (C.T.); (V.P.-C.); (R.B.)
| | - Wouter P. R. Verdurmen
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Medical Center, Geert Grooteplein 28, 6525 GA Nijmegen, The Netherlands; (C.T.); (V.P.-C.); (R.B.)
- Correspondence:
| |
Collapse
|
17
|
Atallah I, Quinodoz M, Campos-Xavier B, Peter VG, Fouriki A, Bonvin C, Bottani A, Kumps C, Angelini F, Bellutti Enders F, Christen-Zaech S, Rizzi M, Renella R, Beck-Popovic M, Poloni C, Frossard V, Blouin JL, Rivolta C, Riccio O, Candotti F, Hofer M, Unger S, Superti-Furga A. Immune deficiency, autoimmune disease and intellectual disability: A pleiotropic disorder caused by biallelic variants in the TPP2 gene. Clin Genet 2021; 99:780-788. [PMID: 33586135 DOI: 10.1111/cge.13942] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/10/2021] [Accepted: 02/11/2021] [Indexed: 12/16/2022]
Abstract
Four individuals from two families presented with a multisystemic condition of suspected genetic origin that was diagnosed only after genome analysis. The main phenotypic features were immune system dysregulation (severe immunodeficiency with autoimmunity) and intellectual disability. The four individuals were found to be homozygous for a 4.4 Kb deletion removing exons 20-23 (NM_003291.4) of the TPP2 gene, predicting a frameshift with premature termination of the protein. The deletion was located on a shared chromosome 13 haplotype indicating a Swiss founder mutation. Tripeptidyl peptidase 2 (TPP2) is a protease involved in HLA/antigen complex processing and amino acid homeostasis. Biallelic variants in TPP2 have been described in 10 individuals with variable features including immune deficiency, autoimmune cytopenias, and intellectual disability or chronic sterile brain inflammation mimicking multiple sclerosis. Our observations further delineate this severe condition not yet included in the OMIM catalog. Timely recognition of TPP2 deficiency is crucial since (1) immune surveillance is needed and hematopoietic stem cell transplantation may be necessary, and (2) for provision of genetic counselling. Additionally, enzyme replacement therapy, as already established for TPP1 deficiency, might be an option in the future.
Collapse
Affiliation(s)
- Isis Atallah
- Division of Genetic Medicine, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Mathieu Quinodoz
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Switzerland.,Department of Ophthalmology, University of Basel, Basel, Switzerland.,Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
| | - Belinda Campos-Xavier
- Division of Genetic Medicine, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Virginie G Peter
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Switzerland.,Department of Ophthalmology, University of Basel, Basel, Switzerland.,Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
| | - Athina Fouriki
- Pediatric Immunology Unit, Division of Pediatrics, Lausanne University Hospital, Lausanne, Switzerland
| | - Christophe Bonvin
- Division of Neurology, Lausanne University Hospital, Lausanne, Switzerland
| | - Armand Bottani
- Division of Genetic Medicine, Geneva University Hospitals, Geneva, Switzerland
| | - Camille Kumps
- Division of Genetic Medicine, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Federica Angelini
- Pediatric Immunology Unit, Division of Pediatrics, Lausanne University Hospital, Lausanne, Switzerland
| | - Felicitas Bellutti Enders
- Pediatric Immunology Unit, Division of Pediatrics, Lausanne University Hospital, Lausanne, Switzerland
| | | | - Mattia Rizzi
- Pediatric Hemato-Oncology Unit, Lausanne University Hospital, Lausanne, Switzerland
| | - Raffaele Renella
- Pediatric Hemato-Oncology Unit, Lausanne University Hospital, Lausanne, Switzerland
| | - Maja Beck-Popovic
- Pediatric Hemato-Oncology Unit, Lausanne University Hospital, Lausanne, Switzerland
| | - Claudia Poloni
- Pediatric Neurology Unit, Sion Hospital, Sion, Switzerland
| | | | - Jean-Louis Blouin
- Division of Genetic Medicine, Geneva University Hospitals, Geneva, Switzerland
| | - Carlo Rivolta
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Switzerland.,Department of Ophthalmology, University of Basel, Basel, Switzerland.,Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
| | - Orbicia Riccio
- Division of Immunology and Allergy, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Fabio Candotti
- Division of Immunology and Allergy, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Michael Hofer
- Pediatric Immunology Unit, Division of Pediatrics, Lausanne University Hospital, Lausanne, Switzerland
| | - Sheila Unger
- Division of Genetic Medicine, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Andrea Superti-Furga
- Division of Genetic Medicine, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| |
Collapse
|
18
|
Kalinin EV, Chalenko YM, Sysolyatina EV, Midiber KY, Gusarov AM, Kechko OI, Kulikova AA, Mikhaleva LM, Mukhachev AY, Stanishevskyi YM, Mitkevich VA, Sobyanin KA, Ermolaeva SA. Bacterial hepatocyte growth factor receptor agonist stimulates hepatocyte proliferation and accelerates liver regeneration in a partial hepatectomy rat model. Drug Dev Res 2021; 82:123-132. [PMID: 32830369 DOI: 10.1002/ddr.21737] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 08/06/2020] [Accepted: 08/07/2020] [Indexed: 12/20/2022]
Abstract
Hepatocyte growth factor (HGF) is central to liver regeneration. The Internalin B (InlB) protein is a virulence factor produced by the pathogenic bacterium Listeria monocytogenes. InlB is known to mimic HGF activity by interacting with the HGF receptor (HGFR) and activating HGFR-controlled signaling pathways. We expressed and purified the HGFR-binding InlB domain, InlB321/15, cloned from the fully virulent clinical L. monocytogenes strain. HGFR and Erk1/2 phosphorylation was determined using Western blotting. The capacity of InlB321/15 to bind HGFR was measured using microscale thermophoresis. Liver regeneration was studied in a model of 70% partial hepatectomy (70%PHx) in male Wistar rats. The nuclear grade parameters were quantified using manual (percentage of binuclear hepatocytes), automated (nuclear diameters), or combined (Ki67 proliferation index) scoring methods. Purified InlB321/15 stimulated HGFR and Erk1/2 phosphorylation and accelerated the proliferation of HepG2 cells. InlB321/15 bound HGFR with Kd = 7.4 ± 1.3 nM. InlB321/15 injected intravenously on the second, fourth, and sixth days after surgery recovered the liver mass and improved the nuclear grade parameters. Seven days post 70% PHx, the liver weight indexes were 2.9 and 2.0%, the hepatocyte proliferation indexes were 19.8 and 0.6%, and the percentages of binucleated hepatocytes were 6.7 and 4.0%, in the InlB321/15-treated and control animals, respectively. Obtained data demonstrated that InlB321/15 improved hepatocyte proliferation and stimulated liver regeneration in animals with 70% hepatectomy.
Collapse
Affiliation(s)
- Egor V Kalinin
- Gamaleya Research Center of Epidemiology and Microbiology, Moscow, Russia
- Peoples' Friendship University of Russia (RUDN University), Moscow, Russia
| | - Yaroslava M Chalenko
- Gamaleya Research Center of Epidemiology and Microbiology, Moscow, Russia
- Federal Research Center for Virology and Microbiology (FRCVM), Russian Academy of Sciences, Moscow, Russia
| | | | | | - Alexey M Gusarov
- Gamaleya Research Center of Epidemiology and Microbiology, Moscow, Russia
| | - Olga I Kechko
- Engelhardt Institute of Molecular Biology, Moscow, Russia
| | | | | | | | | | | | | | - Svetlana A Ermolaeva
- Gamaleya Research Center of Epidemiology and Microbiology, Moscow, Russia
- Federal Research Center for Virology and Microbiology (FRCVM), Russian Academy of Sciences, Moscow, Russia
| |
Collapse
|
19
|
Cai Y, Yu S, Chi X, Radoshitzky SR, Kuhn JH, Berger EA. An immunotoxin targeting Ebola virus glycoprotein inhibits Ebola virus production from infected cells. PLoS One 2021; 16:e0245024. [PMID: 33411835 PMCID: PMC7790382 DOI: 10.1371/journal.pone.0245024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 12/19/2020] [Indexed: 12/29/2022] Open
Abstract
Ebola virus (EBOV), a member of the mononegaviral family Filoviridae, causes severe disease associated with high lethality in humans. Despite enormous progress in development of EBOV medical countermeasures, no anti-EBOV treatment has been approved. We designed an immunotoxin in which a single-chain variable region fragment of the EBOV glycoprotein-specific monoclonal antibody 6D8 was fused to the effector domains of Pseudomonas aeruginosa exotoxin A (PE38). This immunotoxin, 6D8-PE38, bound specifically to cells expressing EBOV glycoproteins. Importantly, 6D8-PE38 targeted EBOV-infected cells, as evidenced by inhibition of infectious EBOV production from infected cells, including primary human macrophages. The data presented here provide a proof of concept for immunotoxin-based targeted killing of infected cells as a potential antiviral intervention for Ebola virus disease.
Collapse
Affiliation(s)
- Yingyun Cai
- Integrated Research Facility at Fort Detrick, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, Frederick, Maryland, United States of America
| | - Shuiqing Yu
- Integrated Research Facility at Fort Detrick, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, Frederick, Maryland, United States of America
| | - Xiaoli Chi
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland, United States of America
- The Geneva Foundation, Tacoma, Washington, United States of America
| | - Sheli R. Radoshitzky
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland, United States of America
- The Geneva Foundation, Tacoma, Washington, United States of America
| | - Jens H. Kuhn
- Integrated Research Facility at Fort Detrick, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, Frederick, Maryland, United States of America
| | - Edward A. Berger
- Laboratory of Viral Disease, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, Maryland, United States of America
| |
Collapse
|
20
|
Harnessing the Membrane Translocation Properties of AB Toxins for Therapeutic Applications. Toxins (Basel) 2021; 13:toxins13010036. [PMID: 33418946 PMCID: PMC7825107 DOI: 10.3390/toxins13010036] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 12/28/2020] [Accepted: 01/01/2021] [Indexed: 12/31/2022] Open
Abstract
Over the last few decades, proteins and peptides have become increasingly more common as FDA-approved drugs, despite their inefficient delivery due to their inability to cross the plasma membrane. In this context, bacterial two-component systems, termed AB toxins, use various protein-based membrane translocation mechanisms to deliver toxins into cells, and these mechanisms could provide new insights into the development of bio-based drug delivery systems. These toxins have great potential as therapies both because of their intrinsic properties as well as the modular characteristics of both subunits, which make them highly amenable to conjugation with various drug classes. This review focuses on the therapeutical approaches involving the internalization mechanisms of three representative AB toxins: botulinum toxin type A, anthrax toxin, and cholera toxin. We showcase several specific examples of the use of these toxins to develop new therapeutic strategies for numerous diseases and explain what makes these toxins promising tools in the development of drugs and drug delivery systems.
Collapse
|
21
|
Becker L, Verdurmen WPR, Plückthun A. Reengineering anthrax toxin protective antigen for improved receptor-specific protein delivery. BMC Biol 2020; 18:100. [PMID: 32792013 PMCID: PMC7427085 DOI: 10.1186/s12915-020-00827-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 07/10/2020] [Indexed: 01/27/2023] Open
Abstract
Background To increase the size of the druggable proteome, it would be highly desirable to devise efficient methods to translocate designed binding proteins to the cytosol, as they could specifically target flat and hydrophobic protein-protein interfaces. If this could be done in a manner dependent on a cell surface receptor, two layers of specificity would be obtained: one for the cell type and the other for the cytosolic target. Bacterial protein toxins have naturally evolved such systems. Anthrax toxin consists of a pore-forming translocation unit (protective antigen (PA)) and a separate protein payload. When engineering PA to ablate binding to its own receptor and instead binding to a receptor of choice, by fusing a designed ankyrin repeat protein (DARPin), uptake in new cell types can be achieved. Results Prepore-to-pore conversion of redirected PA already occurs at the cell surface, limiting the amount of PA that can be administered and thus limiting the amount of delivered payload. We hypothesized that the reason is a lack of a stabilizing interaction with wild-type PA receptor. We have now reengineered PA to incorporate the binding domain of the anthrax receptor CMG2, followed by a DARPin, binding to the receptor of choice. This construct is indeed stabilized, undergoes prepore-to-pore conversion only in late endosomes, can be administered to much higher concentrations without showing toxicity, and consequently delivers much higher amounts of payload to the cytosol. Conclusion We believe that this reengineered system is an important step forward to addressing efficient cell-specific delivery of proteins to the cytosol.
Collapse
Affiliation(s)
- Lukas Becker
- Department of Biochemistry, University of Zurich, Winterthurerstr. 190, 8057, Zurich, Switzerland
| | - Wouter P R Verdurmen
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Medical Center, Geert Grooteplein 28, 6525 GA, Nijmegen, The Netherlands
| | - Andreas Plückthun
- Department of Biochemistry, University of Zurich, Winterthurerstr. 190, 8057, Zurich, Switzerland.
| |
Collapse
|
22
|
Salmonella-based platform for efficient delivery of functional binding proteins to the cytosol. Commun Biol 2020; 3:342. [PMID: 32620833 PMCID: PMC7335062 DOI: 10.1038/s42003-020-1072-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 06/11/2020] [Indexed: 12/23/2022] Open
Abstract
Protein-based affinity reagents (like antibodies or alternative binding scaffolds) offer wide-ranging applications for basic research and therapeutic approaches. However, whereas small chemical molecules efficiently reach intracellular targets, the delivery of macromolecules into the cytosol of cells remains a major challenge; thus cytosolic applications of protein-based reagents are rather limited. Some pathogenic bacteria have evolved a conserved type III secretion system (T3SS) which allows the delivery of effector proteins into eukaryotic cells. Here, we enhance the T3SS of an avirulent strain of Salmonella typhimurium to reproducibly deliver multiple classes of recombinant proteins into eukaryotic cells. The efficacy of the system is probed with both DARPins and monobodies to functionally inhibit the paradigmatic and largely undruggable RAS signaling pathway. Thus, we develop a bacterial secretion system for potent cytosolic delivery of therapeutic macromolecules. To develop a bacterial secretion system for cytosolic delivery of therapeutic macromolecules, Chabloz et al. improve an “effectorless” Salmonella strain and combine it with a plasmid modified to boost the secretion of proteins of interest. With this system, they demonstrate efficient translocation of functional DARPins and monobodies into the cytosol of different eukaryotic cells lines and successfully block the paradigmatic RAS pathway.
Collapse
|
23
|
Abstract
AB toxins with built-in cell targeting and endosomal escape mechanisms are attractive intracellular delivery vehicles. However, their compatibility with nucleic-acid-based therapeutics is not fully explored. Arnold et al. demonstrated the first functional siRNA delivery by diphtheria toxin (DT) in vitro, marking an important step in expanding the utility of AB toxins for nucleic acid delivery.
Collapse
|
24
|
Knox SL, Steinauer A, Alpha-Cobb G, Trexler A, Rhoades E, Schepartz A. Quantification of protein delivery in live cells using fluorescence correlation spectroscopy. Methods Enzymol 2020; 641:477-505. [PMID: 32713536 DOI: 10.1016/bs.mie.2020.05.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Fluorescence correlation spectroscopy (FCS) is a quantitative single-molecule method that measures the concentration and rate of diffusion of fluorophore-tagged molecules, both large and small, in vitro and within live cells, and even within discrete cellular compartments. FCS is exceptionally well-suited to directly quantify the efficiency of intracellular protein delivery-specifically, how well different "cell-penetrating" proteins and peptides guide proteinaceous materials into the cytosol and nuclei of live mammalian cells. This article provides an overview of the procedures necessary to execute robust FCS experiments and evaluate endosomal escape efficiencies: preparation of fluorophore-tagged proteins, incubation with mammalian cells and preparation of FCS samples, setup and execution of an FCS experiment, and a detailed discussion of and custom MATLAB® script for analyzing the resulting autocorrelation curves in the context of appropriate diffusion models.
Collapse
Affiliation(s)
- Susan L Knox
- Department of Chemistry, University of California, Berkeley, CA, United States
| | - Angela Steinauer
- Department of Chemistry and Applied Biosciences, Eidgenössische Technische Hochschule Zürich, Zürich, Switzerland
| | - Garrett Alpha-Cobb
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, United States
| | - Adam Trexler
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, United States
| | - Elizabeth Rhoades
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, United States
| | - Alanna Schepartz
- Department of Chemistry, University of California, Berkeley, CA, United States; Department of Molecular and Cell Biology, University of California, Berkeley, CA, United States.
| |
Collapse
|
25
|
Arnold AE, Smith LJ, Beilhartz GL, Bahlmann LC, Jameson E, Melnyk RA, Shoichet MS. Attenuated diphtheria toxin mediates siRNA delivery. SCIENCE ADVANCES 2020; 6:6/18/eaaz4848. [PMID: 32917630 PMCID: PMC7195190 DOI: 10.1126/sciadv.aaz4848] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 01/21/2020] [Indexed: 05/10/2023]
Abstract
Toxins efficiently deliver cargo to cells by binding to cell surface ligands, initiating endocytosis, and escaping the endolysosomal pathway into the cytoplasm. We took advantage of this delivery pathway by conjugating an attenuated diphtheria toxin to siRNA, thereby achieving gene downregulation in patient-derived glioblastoma cells. We delivered siRNA against integrin-β1 (ITGB1)-a gene that promotes invasion and metastasis-and siRNA against eukaryotic translation initiation factor 3 subunit b (eIF-3b)-a survival gene. We demonstrated mRNA downregulation of both genes and the corresponding functional outcomes: knockdown of ITGB1 led to a significant inhibition of invasion, shown with an innovative 3D hydrogel model; and knockdown of eIF-3b resulted in significant cell death. This is the first example of diphtheria toxin being used to deliver siRNAs, and the first time a toxin-based siRNA delivery strategy has been shown to induce relevant genotypic and phenotypic effects in cancer cells.
Collapse
Affiliation(s)
- Amy E Arnold
- Department of Chemistry, University of Toronto, Toronto, ON, Canada
| | - Laura J Smith
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - Greg L Beilhartz
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - Laura C Bahlmann
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - Emma Jameson
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada
| | - Roman A Melnyk
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Molly S Shoichet
- Department of Chemistry, University of Toronto, Toronto, ON, Canada.
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| |
Collapse
|
26
|
The C. difficile toxin B membrane translocation machinery is an evolutionarily conserved protein delivery apparatus. Nat Commun 2020; 11:432. [PMID: 31974369 PMCID: PMC6978384 DOI: 10.1038/s41467-020-14306-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 12/19/2019] [Indexed: 12/13/2022] Open
Abstract
Large Clostridial Toxins (LCTs) are a family of six homologous protein toxins that are implicated in severe disease. LCTs infiltrate host cells using a translocation domain (LCT-T) that contains both cell-surface receptor binding sites and a membrane translocation apparatus. Despite much effort, LCT translocation remains poorly understood. Here we report the identification of 1104 LCT-T homologs, with 769 proteins from bacteria outside of clostridia. Sequences are widely distributed in pathogenic and host-associated species, in a variety of contexts and architectures. Consistent with these homologs being functional toxins, we show that a distant LCT-T homolog from Serratia marcescens acts as a pH-dependent translocase to deliver its effector into host cells. Based on evolutionary footprinting of LCT-T homologs, we further define an evolutionarily conserved translocase region that we show is an autonomous translocase capable of delivering heterologous cargo into host cells. Our work uncovers a broad class of translocating toxins and provides insights into LCT translocation. Large Clostridial toxins infiltrate host cells using a translocation domain (LCT-T). Here, using a genomics-driven approach and functional assays, the authors uncover the presence of distant LCT-T homologs in bacteria outside clostridia and provide evidence for a toxic effector function in the gammaproteobacterium Serratia marcescens.
Collapse
|
27
|
Xu J, He M, Hou X, Wang Y, Shou C, Cai X, Yuan Z, Yin Y, Lan M, Lou K, Zhao Y, Yang Y, Chen X, Gao F. Safe and Efficacious Diphtheria Toxin-Based Treatment for Melanoma: Combination of a Light-On Gene-Expression System and Nanotechnology. Mol Pharm 2019; 17:301-315. [PMID: 31765570 DOI: 10.1021/acs.molpharmaceut.9b01038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The controversy surrounding the use of diphtheria toxin (DT) as a therapeutic agent against tumor cells arises mainly from its unexpected harmfulness to healthy tissues. We encoded the cytotoxic fragment A of DT (DTA) as an objective gene in the Light-On gene-expression system to construct plasmids pGAVPO (pG) and pU5-DTA (pDTA). Meanwhile, a cRGD-modified ternary complex comprising plasmids, chitosan, and liposome (pG&pDTA@cRGD-CL) was prepared as a nanocarrier to ensure transfection efficiency. Benefiting from spatiotemporal control of this light-switchable transgene system and the superior tumor targeting of the carrier, toxins were designed to be expressed selectively in illuminated lesions. In vitro studies suggested that pG&pDTA@cRGD-CL exerted arrest of the S phase in B16F10 cells upon blue light irradiation and, ultimately, induced the apoptosis and necrosis of tumor cells. Such DTA-based treatment exerted enhanced antitumor activity in mice bearing B16F10 xenografts and displayed prolonged survival time with minimal side effects. Hence, we described novel DTA-based therapy combined with nanotechnology and the Light-On gene-expression system: such treatment could be a promising strategy against melanoma.
Collapse
Affiliation(s)
- Jiajun Xu
- Department of Pharmaceutics, School of Pharmacy , East China University of Science and Technology , Shanghai 200237 , China
| | - Muye He
- Department of Pharmaceutics, School of Pharmacy , East China University of Science and Technology , Shanghai 200237 , China
| | - Xinyu Hou
- Department of Pharmaceutics, School of Pharmacy , East China University of Science and Technology , Shanghai 200237 , China
| | - Yan Wang
- Department of Pharmaceutics, School of Pharmacy , East China University of Science and Technology , Shanghai 200237 , China
| | - Chenting Shou
- Department of Pharmaceutics, School of Pharmacy , East China University of Science and Technology , Shanghai 200237 , China
| | - Xiaoran Cai
- Department of Pharmaceutics, School of Pharmacy , East China University of Science and Technology , Shanghai 200237 , China
| | - Zeting Yuan
- Department of Pharmaceutics, School of Pharmacy , East China University of Science and Technology , Shanghai 200237 , China.,Interventional Cancer Institute of Chinese Integrative Medicine, Putuo Hospital , Shanghai University of Traditional Chinese Medicine , Shanghai 200062 , China
| | - Yu Yin
- Department of Pharmaceutics, School of Pharmacy , East China University of Science and Technology , Shanghai 200237 , China
| | - Minbo Lan
- Shanghai Key Laboratory of Functional Materials Chemistry , East China University of Science and Technology , Shanghai 200237 , China
| | - Kaiyan Lou
- Department of Pharmaceutics, School of Pharmacy , East China University of Science and Technology , Shanghai 200237 , China.,State Key Laboratory of Bioreactor Engineering, Shanghai Key Laboratory of New Drug Design and Shanghai Key Laboratory of Chemical Biology , East China University of Science and Technology , Shanghai 200237 , China
| | - Yuzheng Zhao
- Shanghai Key Laboratory of New Drug Design , East China University of Science and Technology , Shanghai 200237 , China.,Synthetic Biology and Biotechnology Laboratory, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology , East China University of Science and Technology , Shanghai 200237 , China.,Optogenetics & Molecular Imaging Interdisciplinary Research Center, CAS Center for Excellence in Brain Science , East China University of Science and Technology , Shanghai 200237 , China
| | - Yi Yang
- Shanghai Key Laboratory of New Drug Design , East China University of Science and Technology , Shanghai 200237 , China.,Synthetic Biology and Biotechnology Laboratory, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology , East China University of Science and Technology , Shanghai 200237 , China.,Optogenetics & Molecular Imaging Interdisciplinary Research Center, CAS Center for Excellence in Brain Science , East China University of Science and Technology , Shanghai 200237 , China
| | - Xianjun Chen
- Shanghai Key Laboratory of New Drug Design , East China University of Science and Technology , Shanghai 200237 , China.,Synthetic Biology and Biotechnology Laboratory, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology , East China University of Science and Technology , Shanghai 200237 , China.,Optogenetics & Molecular Imaging Interdisciplinary Research Center, CAS Center for Excellence in Brain Science , East China University of Science and Technology , Shanghai 200237 , China
| | - Feng Gao
- Department of Pharmaceutics, School of Pharmacy , East China University of Science and Technology , Shanghai 200237 , China.,Shanghai Key Laboratory of Functional Materials Chemistry , East China University of Science and Technology , Shanghai 200237 , China.,Shanghai Key Laboratory of New Drug Design , East China University of Science and Technology , Shanghai 200237 , China.,Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education, School of Pharmacy , East China University of Science and Technology , Shanghai 200237 , China
| |
Collapse
|
28
|
Shafiee F, Aucoin MG, Jahanian-Najafabadi A. Targeted Diphtheria Toxin-Based Therapy: A Review Article. Front Microbiol 2019; 10:2340. [PMID: 31681205 PMCID: PMC6813239 DOI: 10.3389/fmicb.2019.02340] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 09/25/2019] [Indexed: 12/26/2022] Open
Abstract
Cancer remains one of the leading causes of death worldwide. Conventional therapeutic strategies usually offer limited specificity, resulting in severe side effects and toxicity to normal tissues. Targeted cancer therapy, on the other hand, can improve the therapeutic potential of anti-cancer agents and decrease unwanted side effects. Targeted applications of cytolethal bacterial toxins have been found to be especially useful for the specific eradication of cancer cells. Targeting is either mediated by peptides or by protein-targeting moieties, such as antibodies, antibody fragments, cell-penetrating peptides (CPPs), growth factors, or cytokines. Together with a toxin domain, these molecules are more commonly referred to as immunotoxins. Targeting can also be achieved through gene delivery and cell-specific expression of a toxin. Of the available cytolethal toxins, diphtheria toxin (DT) is one of the most frequently used for these strategies. Of the many DT-based therapeutic strategies investigated to date, two immunotoxins, OntakTM and TagraxofuspTM, have gained FDA approval for clinical application. Despite some success with immunotoxins, suicide-gene therapy strategies, whereby controlled tumor-specific expression of DT is used for the eradication of malignant cells, are gaining prominence. The first part of this review focuses on DT-based immunotoxins, and it then discusses recent developments in tumor-specific expression of DT.
Collapse
Affiliation(s)
- Fatemeh Shafiee
- Department of Pharmaceutical Biotechnology, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Marc G Aucoin
- Department of Chemical Engineering, Faculty of Engineering, University of Waterloo, Waterloo, ON, Canada
| | - Ali Jahanian-Najafabadi
- Department of Pharmaceutical Biotechnology, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
| |
Collapse
|
29
|
Kellner A, Taylor M, Banerjee T, Britt CB, Teter K. A binding motif for Hsp90 in the A chains of ADP-ribosylating toxins that move from the endoplasmic reticulum to the cytosol. Cell Microbiol 2019; 21:e13074. [PMID: 31231933 PMCID: PMC6744307 DOI: 10.1111/cmi.13074] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 06/15/2019] [Accepted: 06/19/2019] [Indexed: 12/29/2022]
Abstract
Cholera toxin (Ctx) is an AB-type protein toxin that acts as an adenosine diphosphate (ADP)-ribosyltransferase to disrupt intracellular signalling in the target cell. It moves by vesicle carriers from the cell surface to the endoplasmic reticulum (ER) of an intoxicated cell. The catalytic CtxA1 subunit then dissociates from the rest of the toxin, unfolds, and activates the ER-associated degradation system for export to the cytosol. Translocation occurs through an unusual ratchet mechanism in which the cytosolic chaperone Hsp90 couples CtxA1 refolding with CtxA1 extraction from the ER. Here, we report that Hsp90 recognises two peptide sequences from CtxA1: an N-terminal RPPDEI sequence (residues 11-16) and an LDIAPA sequence in the C-terminal region (residues 153-158) of the 192 amino acid protein. Peptides containing either sequence effectively blocked Hsp90 binding to full-length CtxA1. Both sequences were necessary for the ER-to-cytosol export of CtxA1. Mutagenesis studies further demonstrated that the RPP residues in the RPPDEI motif are required for CtxA1 translocation to the cytosol. The LDIAPA sequence is unique to CtxA1, but we identified an RPPDEI-like motif at the N- or C-termini of the A chains from four other ER-translocating toxins that act as ADP-ribosyltransferases: pertussis toxin, Escherichia coli heat-labile toxin, Pseudomonas aeruginosa exotoxin A, and Salmonella enterica serovar Typhimurium ADP-ribosylating toxin. Hsp90 plays a functional role in the intoxication process for most, if not all, of these toxins. Our work has established a defined RPPDEI binding motif for Hsp90 that is required for the ER-to-cytosol export of CtxA1 and possibly other toxin A chains as well.
Collapse
Affiliation(s)
- Alisha Kellner
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32826
| | - Michael Taylor
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32826
| | | | - Christopher B.T. Britt
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32826
| | - Ken Teter
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32826
| |
Collapse
|
30
|
Schmit NE, Neopane K, Hantschel O. Targeted Protein Degradation through Cytosolic Delivery of Monobody Binders Using Bacterial Toxins. ACS Chem Biol 2019; 14:916-924. [PMID: 31025848 PMCID: PMC7316569 DOI: 10.1021/acschembio.9b00113] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
![]()
Monobodies
are small engineered binding proteins that, upon expression
in cells, can inhibit signaling of cytosolic oncoproteins with outstanding
selectivity. Efficacy may be further increased by inducing degradation
of monobody targets through fusion to the von Hippel–Lindau
(VHL) substrate receptor of the Cullin2-E3 ubiquitin ligase complex.
However, potential therapeutic use is currently limited, because of
the inability of monobody proteins to cross cellular membranes. Here,
we use a chimeric bacterial toxin, composed of the Shiga-like toxin
B (Stx2B) subunit and the translocation domain of Pseudomonas
aeruginosa exotoxin A (ETA-II) for delivery of VHL–monobody
protein fusions to target endogenous tyrosine kinases in cancer cells.
Depending on the expression of the Stx2B receptor Gb3 on the cell
surface, we show that monobodies are taken up by an endocytic route,
but are not degraded in lysosomes. Delivery of monobodies fused to
a nuclear localization signal resulted in accumulation in the nucleus,
thereby indirectly, but unequivocally, demonstrating cytosolic delivery.
Delivery of VHL fused to monobodies targeting the Lck tyrosine kinase
in T-cells resulted in reduced Lck protein levels, which was dependent
on the expression of Gb3. This led to the inhibition of proximal signaling
events downstream of the T-cell receptor complex. This work provides
a prime example of the delivery of a stoichiometric protein inhibitor
of an endogenous target protein to cells and inducing its degradation
without the need of genetic manipulation of target cells. It lays
the foundation for further in vivo exploitation of
this delivery system.
Collapse
Affiliation(s)
- Nadine Eliane Schmit
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Katyayanee Neopane
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Oliver Hantschel
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| |
Collapse
|
31
|
Deprey K, Becker L, Kritzer J, Plückthun A. Trapped! A Critical Evaluation of Methods for Measuring Total Cellular Uptake versus Cytosolic Localization. Bioconjug Chem 2019; 30:1006-1027. [PMID: 30882208 PMCID: PMC6527423 DOI: 10.1021/acs.bioconjchem.9b00112] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Biomolecules have many properties that make them promising for intracellular therapeutic applications, but delivery remains a key challenge because large biomolecules cannot easily enter the cytosol. Furthermore, quantification of total intracellular versus cytosolic concentrations remains demanding, and the determination of delivery efficiency is thus not straightforward. In this review, we discuss strategies for delivering biomolecules into the cytosol and briefly summarize the mechanisms of uptake for these systems. We then describe commonly used methods to measure total cellular uptake and, more selectively, cytosolic localization, and discuss the major advantages and drawbacks of each method. We critically evaluate methods of measuring "cell penetration" that do not adequately distinguish total cellular uptake and cytosolic localization, which often lead to inaccurate interpretations of a molecule's cytosolic localization. Finally, we summarize the properties and components of each method, including the main caveats of each, to allow for informed decisions about method selection for specific applications. When applied correctly and interpreted carefully, methods for quantifying cytosolic localization offer valuable insight into the bioactivity of biomolecules and potentially the prospects for their eventual development into therapeutics.
Collapse
Affiliation(s)
- Kirsten Deprey
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Lukas Becker
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Joshua Kritzer
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Andreas Plückthun
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| |
Collapse
|
32
|
Wissner R, Steinauer A, Knox SL, Thompson AD, Schepartz A. Fluorescence Correlation Spectroscopy Reveals Efficient Cytosolic Delivery of Protein Cargo by Cell-Permeant Miniature Proteins. ACS CENTRAL SCIENCE 2018; 4:1379-1393. [PMID: 30410976 PMCID: PMC6202653 DOI: 10.1021/acscentsci.8b00446] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Indexed: 05/21/2023]
Abstract
New methods for delivering proteins into the cytosol of mammalian cells are being reported at a rapid pace. Differentiating between these methods in a quantitative manner is difficult, however, as most assays for evaluating cytosolic protein delivery are qualitative and indirect and thus often misleading. Here we make use of fluorescence correlation spectroscopy (FCS) to determine with precision and accuracy the relative efficiencies with which seven different previously reported "cell-penetrating peptides" (CPPs) transport a model protein cargo-the self-labeling enzyme SNAP-tag-beyond endosomal membranes and into the cytosol. Using FCS, we discovered that the miniature protein ZF5.3 is an exceptional vehicle for delivering SNAP-tag to the cytosol. When delivered by ZF5.3, SNAP-tag can achieve a cytosolic concentration as high as 250 nM, generally at least 2-fold and as much as 6-fold higher than any other CPP evaluated. Additionally, we show that ZF5.3 can be fused to a second enzyme cargo-the engineered peroxidase APEX2-and reliably delivers the active enzyme to the cell interior. As FCS allows one to realistically assess the relative merits of protein transduction domains, we anticipate that it will greatly accelerate the identification, evaluation, and optimization of strategies to deliver large, intact proteins to intracellular locales.
Collapse
Affiliation(s)
- Rebecca
F. Wissner
- Department
of Chemistry, and Department of Molecular, Cellular, and Developmental
Biology, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Angela Steinauer
- Department
of Chemistry, and Department of Molecular, Cellular, and Developmental
Biology, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Susan L. Knox
- Department
of Chemistry, and Department of Molecular, Cellular, and Developmental
Biology, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Alexander D. Thompson
- Department
of Chemistry, and Department of Molecular, Cellular, and Developmental
Biology, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Alanna Schepartz
- Department
of Chemistry, and Department of Molecular, Cellular, and Developmental
Biology, Yale University, New Haven, Connecticut 06520-8107, United States
| |
Collapse
|
33
|
Stewart MP, Langer R, Jensen KF. Intracellular Delivery by Membrane Disruption: Mechanisms, Strategies, and Concepts. Chem Rev 2018; 118:7409-7531. [PMID: 30052023 PMCID: PMC6763210 DOI: 10.1021/acs.chemrev.7b00678] [Citation(s) in RCA: 406] [Impact Index Per Article: 67.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Intracellular delivery is a key step in biological research and has enabled decades of biomedical discoveries. It is also becoming increasingly important in industrial and medical applications ranging from biomanufacture to cell-based therapies. Here, we review techniques for membrane disruption-based intracellular delivery from 1911 until the present. These methods achieve rapid, direct, and universal delivery of almost any cargo molecule or material that can be dispersed in solution. We start by covering the motivations for intracellular delivery and the challenges associated with the different cargo types-small molecules, proteins/peptides, nucleic acids, synthetic nanomaterials, and large cargo. The review then presents a broad comparison of delivery strategies followed by an analysis of membrane disruption mechanisms and the biology of the cell response. We cover mechanical, electrical, thermal, optical, and chemical strategies of membrane disruption with a particular emphasis on their applications and challenges to implementation. Throughout, we highlight specific mechanisms of membrane disruption and suggest areas in need of further experimentation. We hope the concepts discussed in our review inspire scientists and engineers with further ideas to improve intracellular delivery.
Collapse
Affiliation(s)
- Martin P. Stewart
- Department of Chemical Engineering, Massachusetts Institute
of Technology, Cambridge, USA
- The Koch Institute for Integrative Cancer Research,
Massachusetts Institute of Technology, Cambridge, USA
| | - Robert Langer
- Department of Chemical Engineering, Massachusetts Institute
of Technology, Cambridge, USA
- The Koch Institute for Integrative Cancer Research,
Massachusetts Institute of Technology, Cambridge, USA
| | - Klavs F. Jensen
- Department of Chemical Engineering, Massachusetts Institute
of Technology, Cambridge, USA
| |
Collapse
|
34
|
Paliga D, Raudzus F, Leppla SH, Heumann R, Neumann S. Lethal Factor Domain-Mediated Delivery of Nurr1 Transcription Factor Enhances Tyrosine Hydroxylase Activity and Protects from Neurotoxin-Induced Degeneration of Dopaminergic Cells. Mol Neurobiol 2018; 56:3393-3403. [PMID: 30121937 PMCID: PMC6476859 DOI: 10.1007/s12035-018-1311-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 08/08/2018] [Indexed: 12/31/2022]
Abstract
The orphan transcription factor nuclear receptor-related 1 protein (Nurr1, also known as NR4A2) plays a key role in embryonic development and maintenance of mesencephalic dopaminergic neurons in the substantia nigra. Nurr1 deficiency is associated with Parkinson’s disease where dopaminergic neurons degenerate suggesting that counter-regulation of Nurr1 activity may have therapeutic effects. Here, we bacterially expressed and isolated a human Nurr1 fusion protein containing a N-terminal cell delivery domain derived from detoxified anthrax lethal factor followed by wild type ubiquitin with deubiquitinating enzyme recognition site for intracellular cleavage. Addition of the Nurr1 fusion protein to dopaminergic SH-SY5Y cells generated a cleaved, cytosolic Nurr1-containing fragment which was associated with increased levels of tyrosine hydroxylase, the rate-limiting enzyme in dopamine synthesis. Promoter-activity assays confirmed that exposure of cells to full-length Nurr1 fusion protein activated not only its cognate human tyrosine hydroxylase promoter but also the corresponding mouse sequence, although at a reduced efficiency. Using 6-hydroxydopamine as a dopaminergic cell specific neurotoxin, we demonstrate that full-length Nurr1 fusion protein promotes a concentration-dependent protection from this toxic insult. Altogether, the enhancement of tyrosine hydroxylase in naïve dopaminergic cells and the protective effects in a cellular model of Parkinson’s disease suggest that full-length Nurr1 fusion protein may contribute to the development of a novel concept of protein-based therapy.
Collapse
Affiliation(s)
- Dennis Paliga
- Department of Biochemistry II - Molecular Neurobiochemistry, Faculty of Chemistry and Biochemistry, Ruhr-Universität Bochum, 44801, Bochum, Germany
| | - Fabian Raudzus
- Department of Biochemistry II - Molecular Neurobiochemistry, Faculty of Chemistry and Biochemistry, Ruhr-Universität Bochum, 44801, Bochum, Germany
| | - Stephen H Leppla
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Rolf Heumann
- Department of Biochemistry II - Molecular Neurobiochemistry, Faculty of Chemistry and Biochemistry, Ruhr-Universität Bochum, 44801, Bochum, Germany.
| | - Sebastian Neumann
- Department of Biochemistry II - Molecular Neurobiochemistry, Faculty of Chemistry and Biochemistry, Ruhr-Universität Bochum, 44801, Bochum, Germany
| |
Collapse
|
35
|
Haywood EE, Ho M, Wilson BA. Modular domain swapping among the bacterial cytotoxic necrotizing factor (CNF) family for efficient cargo delivery into mammalian cells. J Biol Chem 2018; 293:3860-3870. [PMID: 29371399 DOI: 10.1074/jbc.ra117.001381] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 01/11/2018] [Indexed: 11/06/2022] Open
Abstract
Modular AB-type bacterial protein toxins target mammalian host cells with high specificity and deliver their toxic cargo into the cytosol. Hence, these toxins are being explored as agents for targeted cytosolic delivery in biomedical and research applications. The cytotoxic necrotizing factor (CNF) family is unique among these toxins in that their homologous sequences are found in a wide array of bacteria, and their activity domains are packaged in various delivery systems. Here, to study how CNF cargo and delivery modules can be assembled for efficient cytosolic delivery, we generated chimeric toxins by swapping functional domains among CNF1, CNF2, CNF3, and CNFy. Chimeras with a CNFy delivery vehicle were more stably expressed, but were less efficient at cargo delivery into HEK293-T cells. We also found that CNFy cargo is the most universally compatible and that CNF3 delivery vehicle is the most flexible and efficient at delivering cargo. These findings suggest that domains within proteins can be swapped and accommodate each other for efficient function and that an individual domain could be engineered for compatibility with multiple partner domains. We anticipate that our insights could help inform chemical biology approaches to develop toxin-based cargo-delivery platforms for cytosolic cargo delivery of therapeutics or molecular probes into mammalian cells.
Collapse
Affiliation(s)
- Elizabeth E Haywood
- From the Department of Microbiology, School of Molecular and Cellular Biology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801
| | - Mengfei Ho
- From the Department of Microbiology, School of Molecular and Cellular Biology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801
| | - Brenda A Wilson
- From the Department of Microbiology, School of Molecular and Cellular Biology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801
| |
Collapse
|
36
|
Luginbuehl V, Meier N, Kovar K, Rohrer J. Intracellular drug delivery: Potential usefulness of engineered Shiga toxin subunit B for targeted cancer therapy. Biotechnol Adv 2018; 36:613-623. [PMID: 29432805 DOI: 10.1016/j.biotechadv.2018.02.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 01/30/2018] [Accepted: 02/05/2018] [Indexed: 12/15/2022]
Abstract
A treasure trove of intracellular cancer drug targets remains hidden behind cell membranes. However, engineered pathogen-derived toxins such as Shiga toxins can deliver small or macromolecular drugs to specific intracellular organelles. After binding to ganglioglobotriaosylceramide (Gb3, CD77), the non-toxic subunit B (StxB) of the Shiga-holotoxin is endocytosed and delivers its payload by a unique retrograde trafficking pathway via the endoplasmic reticulum to the cytosol. This review provides an overview of biomedical applications of StxB-based drug delivery systems in targeted cancer diagnosis and therapy. Biotechnological production of the Stx-material is discussed from the perspective of developing efficacious and safe therapeutics.
Collapse
Affiliation(s)
- Vera Luginbuehl
- Institute of Chemistry and Biotechnology, Zurich University of Applied Sciences, Grueental, P.O.X. 335, CH-8820 Waedenswil, Switzerland
| | - Nicolas Meier
- Institute of Chemistry and Biotechnology, Zurich University of Applied Sciences, Grueental, P.O.X. 335, CH-8820 Waedenswil, Switzerland
| | - Karin Kovar
- Institute of Chemistry and Biotechnology, Zurich University of Applied Sciences, Grueental, P.O.X. 335, CH-8820 Waedenswil, Switzerland
| | - Jack Rohrer
- Institute of Chemistry and Biotechnology, Zurich University of Applied Sciences, Grueental, P.O.X. 335, CH-8820 Waedenswil, Switzerland.
| |
Collapse
|
37
|
Larabee JL, Hauck GD, Ballard JD. Cell-penetrating peptides derived from Clostridium difficile TcdB2 and a related large clostridial toxin. J Biol Chem 2017; 293:1810-1819. [PMID: 29247010 DOI: 10.1074/jbc.m117.815373] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 12/12/2017] [Indexed: 12/15/2022] Open
Abstract
Clostridium difficile TcdB (2366 amino acid residues) is an intracellular bacterial toxin that binds to cells and enters the cytosol where it glucosylates small GTPases. In the current study, we examined a putative cell entry region of TcdB (amino acid residues 1753-1851) for short sequences that function as cell-penetrating peptides (CPPs). To screen for TcdB-derived CPPs, a panel of synthetic peptides was tested for the ability to enhance transferrin (Tf) association with cells. Four candidate CPPs were discovered, and further study on one peptide (PepB2) pinpointed an asparagine residue necessary for CPP activity. PepB2 mediated the cell entry of a wide variety of molecules including dextran, streptavidin, microspheres, and lentivirus particles. Of note, this uptake was dramatically reduced in the presence of the Na+/H+ exchange blocker and micropinocytosis inhibitor amiloride, suggesting that PepB2 invokes macropinocytosis. Moreover, we found that PepB2 had more efficient cell-penetrating activity than several other well-known CPPs (TAT, penetratin, Pep-1, and TP10). Finally, Tf assay-based screening of peptides derived from two other large clostridial toxins, TcdA and TcsL, uncovered two new TcdA-derived CPPs. In conclusion, we have identified six CPPs from large clostridial toxins and have demonstrated the ability of PepB2 to promote cell association and entry of several molecules through a putative fluid-phase macropinocytotic mechanism.
Collapse
Affiliation(s)
- Jason L Larabee
- From the Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| | - Garrett D Hauck
- From the Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| | - Jimmy D Ballard
- From the Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| |
Collapse
|