1
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ERK and c-Myc signaling in host-derived tumor endothelial cells is essential for solid tumor growth. Proc Natl Acad Sci U S A 2023; 120:e2211927120. [PMID: 36574698 PMCID: PMC9910475 DOI: 10.1073/pnas.2211927120] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The limited efficacy of the current antitumor microenvironment strategies is due in part to the poor understanding of the roles and relative contributions of the various tumor stromal cells to tumor development. Here, we describe a versatile in vivo anthrax toxin protein delivery system allowing for the unambiguous genetic evaluation of individual tumor stromal elements in cancer. Our reengineered tumor-selective anthrax toxin exhibits potent antiproliferative activity by disrupting ERK signaling in sensitive cells. Since this activity requires the surface expression of the capillary morphogenesis protein-2 (CMG2) toxin receptor, genetic manipulation of CMG2 expression using our cell-type-specific CMG2 transgenic mice allows us to specifically define the role of individual tumor stromal cell types in tumor development. Here, we established mice with CMG2 only expressed in tumor endothelial cells (ECs) and determined the specific contribution of tumor stromal ECs to the toxin's antitumor activity. Our results demonstrate that disruption of ERK signaling only within tumor ECs is sufficient to halt tumor growth. We discovered that c-Myc is a downstream effector of ERK signaling and that the MEK-ERK-c-Myc central metabolic axis in tumor ECs is essential for tumor progression. As such, disruption of ERK-c-Myc signaling in host-derived tumor ECs by our tumor-selective anthrax toxins explains their high efficacy in solid tumor therapy.
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2
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Zuo Z, Liu J, Sun Z, Silverstein R, Zou M, Finkel T, Bugge TH, Leppla SH, Liu S. A potent tumor-selective ERK pathway inactivator with high therapeutic index. PNAS NEXUS 2022; 1:pgac104. [PMID: 35899070 PMCID: PMC9308561 DOI: 10.1093/pnasnexus/pgac104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 06/28/2022] [Indexed: 02/05/2023]
Abstract
FDA-approved BRAF and MEK small molecule inhibitors have demonstrated some level of efficacy in patients with metastatic melanomas. However, these "targeted" therapeutics have a very low therapeutic index, since these agents affect normal cells, causing undesirable, even fatal, side effects. To address these significant drawbacks, here, we have reengineered the anthrax toxin-based protein delivery system to develop a potent, tumor-selective MEK inactivator. This toxin-based MEK inactivator exhibits potent activity against a wide range of solid tumors, with the highest activity seen when directed toward tumors containing the BRAFV600E mutation. We demonstrate that this reengineered MEK inactivator also exhibits an extremely high therapeutic index (>15), due to its in vitro and in vivo activity being strictly dependent on the expression of multiple tumor-associated factors including tumor-associated proteases matrix metalloproteinase, urokinase plasminogen activator, and anthrax toxin receptor capillary morphogenesis protein-2. Furthermore, we have improved the specificity of this MEK inactivator, restricting its enzymatic activity to only target the ERK pathway, thereby greatly diminishing off-target toxicity. Together, these data suggest that engineered bacterial toxins can be modified to have significant in vitro and in vivo therapeutic effects with high therapeutic index.
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Affiliation(s)
| | | | - Zhihao Sun
- Aging Institute of University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA
| | - Rachel Silverstein
- Aging Institute of University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA
| | - Meijuan Zou
- Aging Institute of University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA
| | - Toren Finkel
- Aging Institute of University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA,Division of Cardiology, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Thomas H Bugge
- Proteases and Tissue Remodeling Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA
| | - Stephen H Leppla
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Shihui Liu
- To whom correspondence should be addressed:
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3
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Lu Z, Truex NL, Melo MB, Cheng Y, Li N, Irvine DJ, Pentelute BL. IgG-Engineered Protective Antigen for Cytosolic Delivery of Proteins into Cancer Cells. ACS CENTRAL SCIENCE 2021; 7:365-378. [PMID: 33655074 PMCID: PMC7908032 DOI: 10.1021/acscentsci.0c01670] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Indexed: 05/05/2023]
Abstract
Therapeutic immunotoxins composed of antibodies and bacterial toxins provide potent activity against malignant cells, but joining them with a defined covalent bond while maintaining the desired function is challenging. Here, we develop novel immunotoxins by dovetailing full-length immunoglobulin G (IgG) antibodies and nontoxic anthrax proteins, in which the C terminus of the IgG heavy chain is connected to the side chain of anthrax toxin protective antigen. This strategy enabled efficient conjugation of protective antigen variants to trastuzumab (Tmab) and cetuximab (Cmab) antibodies. The conjugates effectively perform intracellular delivery of edema factor and N terminus of lethal factor (LFN) fused with diphtheria toxin and Ras/Rap1-specific endopeptidase. Each conjugate shows high specificity for cells expressing human epidermal growth factor receptor 2 (HER2) and epidermal growth factor receptor (EGFR), respectively, and potent activity across six Tmab- and Cmab-resistant cell lines. The conjugates also exhibit increased pharmacokinetics and pronounced in vivo safety, which shows promise for further therapeutic development.
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Affiliation(s)
- Zeyu Lu
- Department
of Chemistry, Massachusetts Institute of
Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Nicholas L. Truex
- Department
of Chemistry, Massachusetts Institute of
Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Mariane B. Melo
- The
Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main Street, Cambridge, Massachusetts 02142, United States
- Ragon
Institute of Massachusetts General Hospital, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Yiran Cheng
- Department
of Chemistry, Massachusetts Institute of
Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Na Li
- The
Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main Street, Cambridge, Massachusetts 02142, United States
| | - Darrell J. Irvine
- The
Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main Street, Cambridge, Massachusetts 02142, United States
- Ragon
Institute of Massachusetts General Hospital, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Department
of Materials Science and Engineering, Massachusetts
Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Department
of Biological Engineering, Massachusetts
Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Howard Hughes
Medical Institute, 4000
Jones Bridge Road, Chevy Chase, Maryland 20815, United
States
| | - Bradley L. Pentelute
- Department
of Chemistry, Massachusetts Institute of
Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- The
Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main Street, Cambridge, Massachusetts 02142, United States
- Center
for Environmental Health Sciences, Massachusetts
Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Broad
Institute of MIT and Harvard, 415 Main Street, Cambridge, Massachusetts 02142, United States
- E-mail:
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4
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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.
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5
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Xu D, Bum-Erdene K, Leth JM, Ghozayel MK, Ploug M, Meroueh SO. Small-Molecule Inhibition of the uPAR ⋅ uPA Interaction by Conformational Selection. ChemMedChem 2020; 16:377-387. [PMID: 33107192 DOI: 10.1002/cmdc.202000558] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 09/25/2020] [Indexed: 12/12/2022]
Abstract
The urokinase receptor (uPAR) is a cell surface receptor that binds to the serine protease urokinase-type plasminogen activator (uPA) with high affinity. This interaction is beneficial for extravascular fibrin clearance, but it has also been associated with a broad range of pathological conditions including cancer, atherosclerosis, and kidney disease. Here, starting with a small molecule that we previously discovered by virtual screening and cheminformatics analysis, we design and synthesize several derivatives that were tested for binding and inhibition of the uPAR ⋅ uPA interaction. To confirm the binding site and establish a binding mode of the compounds, we carried out biophysical studies using uPAR mutants, among them uPARH47C-N259C , a mutant previously developed to mimic the structure of uPA-bound uPAR. Remarkably, a substantial increase in potency is observed for inhibition of uPARH47C-N259C binding to uPA compared to wild-type uPAR, consistent with our use of the structure of uPAR in its uPA-bound state to design small-molecule uPAR ⋅ uPA antagonists. Combined with the biophysical studies, molecular docking followed by extensive explicit-solvent molecular dynamics simulations and MM-GBSA free energy calculations yielded the most favorable binding pose of the compound. Collectively, these results suggest that potent inhibition of uPAR binding to uPA with small molecules will likely only be achieved by developing small molecules that exhibit high-affinity to solution apo structures of uPAR, rather than uPA-bound structures of the receptor.
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Affiliation(s)
- David Xu
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.,Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Khuchtumur Bum-Erdene
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Julie M Leth
- Finsen Laboratory, Rigshospitalet, 2200, Copenhagen N, Denmark.,Biotech Research and Innovation Centre, University of Copenhagen, 2200, Copenhagen N, Denmark
| | - Mona K Ghozayel
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Michael Ploug
- Finsen Laboratory, Rigshospitalet, 2200, Copenhagen N, Denmark.,Biotech Research and Innovation Centre, University of Copenhagen, 2200, Copenhagen N, Denmark
| | - Samy O Meroueh
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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6
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Sadeghpour SD, Karimi F, Alizadeh H. Predictive and fluorescent nanosensing experimental methods for evaluating anthrax protective antigen and lethal factor interactions for therapeutic applications. Int J Biol Macromol 2020; 160:1158-1167. [DOI: 10.1016/j.ijbiomac.2020.05.190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 05/22/2020] [Accepted: 05/22/2020] [Indexed: 10/24/2022]
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7
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Lu Z, Paolella BR, Truex NL, Loftis AR, Liao X, Rabideau AE, Brown MS, Busanovich J, Beroukhim R, Pentelute BL. Targeting Cancer Gene Dependencies with Anthrax-Mediated Delivery of Peptide Nucleic Acids. ACS Chem Biol 2020; 15:1358-1369. [PMID: 32348107 PMCID: PMC7521945 DOI: 10.1021/acschembio.9b01027] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Antisense oligonucleotide therapies are important cancer treatments, which can suppress genes in cancer cells that are critical for cell survival. SF3B1 has recently emerged as a promising gene target that encodes a key splicing factor in the SF3B protein complex. Over 10% of cancers have lost one or more copies of the SF3B1 gene, rendering these cancers vulnerable after further suppression. SF3B1 is just one example of a CYCLOPS (Copy-number alterations Yielding Cancer Liabilities Owing to Partial losS) gene, but over 120 additional candidate CYCLOPS genes are known. Antisense oligonucleotide therapies for cancer offer the promise of effective suppression for CYCLOPS genes, but developing these treatments is difficult due to their limited permeability into cells and poor cytosolic stability. Here, we develop an effective approach to suppress CYCLOPS genes by delivering antisense peptide nucleic acids (PNAs) into the cytosol of cancer cells. We achieve efficient cytosolic PNA delivery with the two main nontoxic components of the anthrax toxin: protective antigen (PA) and the 263-residue N-terminal domain of lethal factor (LFN). Sortase-mediated ligation readily enables the conjugation of PNAs to the C terminus of the LFN protein. LFN and PA work together in concert to translocate PNAs into the cytosol of mammalian cells. Antisense SF3B1 PNAs delivered with the LFN/PA system suppress the SF3B1 gene and decrease cell viability, particularly of cancer cells with partial copy-number loss of SF3B1. Moreover, antisense SF3B1 PNAs delivered with a HER2-binding PA variant selectively target cancer cells that overexpress the HER2 cell receptor, demonstrating receptor-specific targeting of cancer cells. Taken together, our efforts illustrate how PA-mediated delivery of PNAs provides an effective and general approach for delivering antisense PNA therapeutics and for targeting gene dependencies in cancer.
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Affiliation(s)
- Zeyu Lu
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | - Brenton R. Paolella
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02139, USA
| | - Nicholas L. Truex
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | - Alexander R. Loftis
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | - Xiaoli Liao
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | - Amy E. Rabideau
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | - Meredith S. Brown
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02139, USA
| | - John Busanovich
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02139, USA
| | - Rameen Beroukhim
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02139, USA
| | - Bradley L. Pentelute
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
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8
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Fischer ES, Campbell WA, Liu S, Ghirlando R, Fattah RJ, Bugge TH, Leppla SH. Bismaleimide cross-linked anthrax toxin forms functional octamers with high specificity in tumor targeting. Protein Sci 2019; 28:1059-1070. [PMID: 30942916 PMCID: PMC6511737 DOI: 10.1002/pro.3613] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 04/01/2019] [Indexed: 12/12/2022]
Abstract
In recent years, anthrax toxin has been reengineered to act as a highly specific antiangiogenic cancer therapeutic, shown to kill tumors in animal models. This has been achieved by modifying protective antigen (PA) so that its activation and toxicity require the presence of two proteases, matrix metalloproteinase (MMP) and urokinase plasminogen activator (uPA), which are upregulated in tumor microenvironments. These therapeutics consist of intercomplementing PA variants, which are individually nontoxic, but form functional toxins upon complementary oligomerization. Here, we have created a dual-protease requiring PA targeting system which utilizes bismaleimide cross-linked PA (CLPA) rather than the intercomplementing PA variants. Three different CLPA agents were tested and, as expected, found to exclusively form octamers. Two of the CLPA agents have in vitro toxicities equal to those of previous intercomplementing agents, while the third CLPA agent had compromised in vitro cleavage and was significantly less cytotoxic. We hypothesize this difference was due to steric hindrance caused by cross-linking two PA monomers in close proximity to the PA cleavage site. Overall, this work advances the development and use of the PA and LF tumor-targeting system as a practical cancer therapeutic, as it provides a way to reduce the drug components of the anthrax toxin drug delivery system from three to two, which may lower the cost and simplify testing in clinical trials. HIGHLIGHT: Previously, anthrax toxin has been reengineered to act as a highly specific antiangiogenic cancer therapeutic. Here, we present a version, which utilizes bismaleimide cross-linked protective antigen (PA) rather than intercomplementing PA variants. This advances the development of anthrax toxin as a practical cancer therapeutic as it reduces the components of the drug delivery system to two, which may lower the cost and simplify testing in clinical trials.
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Affiliation(s)
- Elyse S. Fischer
- Laboratory of Parasitic DiseasesNational Institute of Allergy and Infectious DiseasesBethesdaMaryland
| | - Warren A. Campbell
- Laboratory of Parasitic DiseasesNational Institute of Allergy and Infectious DiseasesBethesdaMaryland
| | - Shihui Liu
- Oral and Pharyngeal Cancer BranchNational Institute of Dental and Craniofacial ResearchBethesdaMaryland
| | - Rodolfo Ghirlando
- Laboratory of Molecular BiologyNational Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of HealthBethesdaMaryland, 20892
| | - Rasem J. Fattah
- Laboratory of Parasitic DiseasesNational Institute of Allergy and Infectious DiseasesBethesdaMaryland
| | - Thomas H. Bugge
- Oral and Pharyngeal Cancer BranchNational Institute of Dental and Craniofacial ResearchBethesdaMaryland
| | - Stephen H. Leppla
- Laboratory of Parasitic DiseasesNational Institute of Allergy and Infectious DiseasesBethesdaMaryland
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9
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Liu M, Lin L, Høyer-Hansen G, Ploug M, Li H, Jiang L, Yuan C, Li J, Huang M. Crystal structure of the unoccupied murine urokinase-type plasminogen activator receptor (uPAR) reveals a tightly packed DII-DIII unit. FEBS Lett 2019; 593:1236-1247. [PMID: 31044429 DOI: 10.1002/1873-3468.13397] [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] [Received: 01/24/2019] [Revised: 04/07/2019] [Accepted: 04/22/2019] [Indexed: 12/16/2022]
Abstract
The urokinase-type plasminogen activator receptor (uPAR) is a cell surface receptor that is capable of binding to a range of extracellular proteins and triggering a series of proteolytic and signaling events. Previous structural studies of uPAR with its ligands uPA and vitronectin revealed that its three domains (DI, DII, and DIII) form a large hydrophobic cavity to accommodate uPA. In the present study, the structure of unoccupied murine uPAR (muPAR) is determined. The structure of DII and DIII of muPAR is well defined and forms a compact globular unit, while DI could not be traced. Molecular dynamic simulations further confirm the rigid binding interface between DII and DIII. This study shows overall structural flexibility of uPAR in the absence of uPA.
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Affiliation(s)
- Min Liu
- College of Biological Science and Engineering, Fuzhou University, China.,College of Life Science, Fujian Normal University, Fuzhou, China
| | - Lin Lin
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Gunilla Høyer-Hansen
- Biotechnology Research Innovation Centre (BRIC), University of Copenhagen, Denmark.,Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark
| | - Michael Ploug
- Biotechnology Research Innovation Centre (BRIC), University of Copenhagen, Denmark.,Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark
| | - Hanlin Li
- College of Chemistry, Fuzhou University, China
| | | | - Cai Yuan
- College of Biological Science and Engineering, Fuzhou University, China
| | - Jinyu Li
- College of Chemistry, Fuzhou University, China
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10
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Leth JM, Mertens HDT, Leth-Espensen KZ, Jørgensen TJD, Ploug M. Did evolution create a flexible ligand-binding cavity in the urokinase receptor through deletion of a plesiotypic disulfide bond? J Biol Chem 2019; 294:7403-7418. [PMID: 30894413 DOI: 10.1074/jbc.ra119.007847] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 03/10/2019] [Indexed: 11/06/2022] Open
Abstract
The urokinase receptor (uPAR) is a founding member of a small protein family with multiple Ly6/uPAR (LU) domains. The motif defining these LU domains contains five plesiotypic disulfide bonds stabilizing its prototypical three-fingered fold having three protruding loops. Notwithstanding the detailed knowledge on structure-function relationships in uPAR, one puzzling enigma remains unexplored. Why does the first LU domain in uPAR (DI) lack one of its consensus disulfide bonds, when the absence of this particular disulfide bond impairs the correct folding of other single LU domain-containing proteins? Here, using a variety of contemporary biophysical methods, we found that reintroducing the two missing half-cystines in uPAR DI caused the spontaneous formation of the corresponding consensus 7-8 LU domain disulfide bond. Importantly, constraints due to this cross-link impaired (i) the binding of uPAR to its primary ligand urokinase and (ii) the flexible interdomain assembly of the three LU domains in uPAR. We conclude that the evolutionary deletion of this particular disulfide bond in uPAR DI may have enabled the assembly of a high-affinity urokinase-binding cavity involving all three LU domains in uPAR. Of note, an analogous neofunctionalization occurred in snake venom α-neurotoxins upon loss of another pair of the plesiotypic LU domain half-cystines. In summary, elimination of the 7-8 consensus disulfide bond in the first LU domain of uPAR did have significant functional and structural consequences.
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Affiliation(s)
- Julie M Leth
- From the Finsen Laboratory, Rigshospitalet, DK-2200 Copenhagen N, Denmark.,the Biotech Research and Innovation Centre (BRIC), University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - Haydyn D T Mertens
- the European Molecular Biology Laboratory Hamburg, Notkestrasse 85, D-22607 Hamburg, Germany, and
| | - Katrine Zinck Leth-Espensen
- From the Finsen Laboratory, Rigshospitalet, DK-2200 Copenhagen N, Denmark.,the Biotech Research and Innovation Centre (BRIC), University of Copenhagen, DK-2200 Copenhagen N, Denmark.,the Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5320 Odense M, Denmark
| | - Thomas J D Jørgensen
- the Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5320 Odense M, Denmark
| | - Michael Ploug
- From the Finsen Laboratory, Rigshospitalet, DK-2200 Copenhagen N, Denmark, .,the Biotech Research and Innovation Centre (BRIC), University of Copenhagen, DK-2200 Copenhagen N, Denmark
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11
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Lei Y, Zhao F, Shao J, Li Y, Li S, Chang H, Zhang Y. Application of built-in adjuvants for epitope-based vaccines. PeerJ 2019; 6:e6185. [PMID: 30656066 PMCID: PMC6336016 DOI: 10.7717/peerj.6185] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 11/29/2018] [Indexed: 12/21/2022] Open
Abstract
Several studies have shown that epitope vaccines exhibit substantial advantages over conventional vaccines. However, epitope vaccines are associated with limited immunity, which can be overcome by conjugating antigenic epitopes with built-in adjuvants (e.g., some carrier proteins or new biomaterials) with special properties, including immunologic specificity, good biosecurity and biocompatibility, and the ability to vastly improve the immune response of epitope vaccines. When designing epitope vaccines, the following types of built-in adjuvants are typically considered: (1) pattern recognition receptor ligands (i.e., toll-like receptors); (2) virus-like particle carrier platforms; (3) bacterial toxin proteins; and (4) novel potential delivery systems (e.g., self-assembled peptide nanoparticles, lipid core peptides, and polymeric or inorganic nanoparticles). This review primarily discusses the current and prospective applications of these built-in adjuvants (i.e., biological carriers) to provide some references for the future design of epitope-based vaccines.
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Affiliation(s)
- Yao Lei
- State Key Laboratory of Veterinary Etiological Biology, OIE/National Foot-and-Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Furong Zhao
- State Key Laboratory of Veterinary Etiological Biology, OIE/National Foot-and-Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Junjun Shao
- State Key Laboratory of Veterinary Etiological Biology, OIE/National Foot-and-Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Yangfan Li
- State Key Laboratory of Veterinary Etiological Biology, OIE/National Foot-and-Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Shifang Li
- State Key Laboratory of Veterinary Etiological Biology, OIE/National Foot-and-Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Huiyun Chang
- State Key Laboratory of Veterinary Etiological Biology, OIE/National Foot-and-Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Yongguang Zhang
- State Key Laboratory of Veterinary Etiological Biology, OIE/National Foot-and-Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
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