1
|
Ming K, Xing B, Hu Y, Mei M, Huang W, Hu X, Wei Z. De novo design of a protein binder against Staphylococcus enterotoxin B. Int J Biol Macromol 2024; 257:128666. [PMID: 38070805 DOI: 10.1016/j.ijbiomac.2023.128666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 12/03/2023] [Accepted: 12/06/2023] [Indexed: 01/26/2024]
Abstract
Staphylococcus enterotoxin B (SEB) interacts with MHC-II molecules to overactivate immune cells and thereby to produce excessive pro-inflammatory cytokines. Disrupting the interactions between SEB and MHC-II helps eliminate the lethal threat posed by SEB. In this study, a de novo computational approach was used to design protein binders targeting SEB. The MHC-II binding domain of SEB was selected as the target, and the possible promising binding mode was broadly explored. The obtained original binder was folded into triple-helix bundles and contained 56 amino acids with molecular weight 5.9 kDa. The interface of SEB and the binder was highly hydrophobic. ProteinMPNN optimization further enlarged the hydrophobic region of the binder and improved the stability of the binder-SEB complex. In vitro study demonstrated that the optimized binder significantly inhibited the inflammatory response induced by SEB. Overall, our research demonstrated the applicability of this approach in de novo designing protein binders against SEB, and thereby providing potential therapeutics for SEB induced diseases.
Collapse
Affiliation(s)
- Ke Ming
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China; Hubei Jiangxia Laboratory, Wuhan, Hubei, PR China
| | - Banbin Xing
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China
| | - Yang Hu
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China
| | - Meng Mei
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China
| | - Wenli Huang
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China
| | - Xiaoyu Hu
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China
| | - Zigong Wei
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China; Hubei Jiangxia Laboratory, Wuhan, Hubei, PR China; Hubei Province Key Laboratory of Biotechnology of Chinese Traditional Medicine, National & Local Joint Engineering Research Center of High-throughput Drug Screening Technology, School of life sciences, Hubei University, Wuhan, Hubei, PR China.
| |
Collapse
|
2
|
Ming K, Hu Y, Zhu M, Xing B, Mei M, Wei Z. Development of nanobodies against Staphylococcus enterotoxin B through yeast surface display. Int J Biol Macromol 2023; 253:126822. [PMID: 37703983 DOI: 10.1016/j.ijbiomac.2023.126822] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 09/06/2023] [Accepted: 09/07/2023] [Indexed: 09/15/2023]
Abstract
Staphylococcus enterotoxin B (SEB) is one of the primary virulence factors of Staphylococcus aureus but there is still a lack of targeted drugs. SEB activates immune cells via interacting with MHC-II on antigen-presenting cells, leading to the production of large amounts of pro-inflammatory cytokines. Blocking the interaction between SEB and MHC-II can avert the overactivation of immune cells. Nanobodies are the smallest functional antibodies that can bind stably to antigens. In this study, an ideal approach to obtain specific nanobodies without immunizing camelids was introduced. We constructed a library containing up to 5 × 108 nanobodies, and then screened those targeting SEB by using yeast surface display (YSD) technique and fluorescence-activated cell sorting (FACS). A total of 8 nanobodies with divergent complementarity-determining regions (CDRs) sequences were identified and one candidate Nb8 with high affinity to SEB was isolated. In vitro study demonstrated that Nb8 significantly inhibited SEB-induced inflammatory response. Molecular docking simulation indicated that the unique CDR3 sequence contributed to the binding of Nb8 to the MHC-II binding domain of SEB and accordingly cut off the connection between SEB and MHC-II. Our efforts contributed to the development of specific nanobodies for eliminating the threats of SEB.
Collapse
Affiliation(s)
- Ke Ming
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China
| | - Yang Hu
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China
| | - Meijun Zhu
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China
| | - Banbin Xing
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China
| | - Meng Mei
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China
| | - Zigong Wei
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China; National & Local Joint Engineering Research Center of High-throughput Drug Screening Technology, School of life sciences, Hubei University, Wuhan, Hubei, PR China.
| |
Collapse
|
3
|
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] [What about the content of this article? (0)] [Affiliation(s)] [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
|
4
|
Goto M, Yoshino S, Hiroshima K, Kawakami T, Murota K, Shimamoto S, Hidaka Y. The Molecular Basis of Heat-Stable Enterotoxin for Vaccine Development and Cancer Cell Detection. Molecules 2023; 28:molecules28031128. [PMID: 36770798 PMCID: PMC9920858 DOI: 10.3390/molecules28031128] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 01/19/2023] [Accepted: 01/20/2023] [Indexed: 01/24/2023] Open
Abstract
Heat-stable enterotoxin (STa) produced by Enterotoxigenic E. coli is responsible for causing acute diarrhea in infants in developing countries. However, the chemical synthesis of STa peptides with the native conformation and the correct intra-molecular disulfide bonds is a major hurdle for vaccine development. To address this issue, we herein report on the design and preparation of STa analogs and a convenient chemical method for obtaining STa molecules with the correct conformation. To develop an STa vaccine, we focused on a structure in a type II β-turn in the STa molecule and introduced a D-Lys residue as a conjugation site for carrier proteins. In addition, the -Glu-Leu- sequence in the STa molecule was replaced with a -Asp-Val- sequence to decrease the toxic activity of the peptide to make it more amenable for use in vaccinations. To solve several issues associated with the synthesis of STa, such as the formation of non-native disulfide isomers, the native disulfide pairings were regioselectively formed in a stepwise manner. A native form or topological isomer of the designed STa peptide, which possesses a right-handed or a left-handed spiral structure, respectively, were synthesized in high synthetic yields. The conformation of the synthetic STa peptide was also confirmed by CD and NMR spectroscopy. To further utilize the designed STa peptide, it was labeled with fluorescein for fluorescent detection, since recent studies have also focused on the use of STa for detecting cancer cells, such as Caco-2 and T84. The labeled STa peptide was able to specifically and efficiently detect 293T cells expressing the recombinant STa receptor (GC-C) protein and Caco-2 cells. The findings reported here provide an outline of the molecular basis for using STa for vaccine development and in the detection of cancer cells.
Collapse
Affiliation(s)
- Masaya Goto
- Faculty of Science and Engineering, Kindai University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan
| | - Shinya Yoshino
- Faculty of Science and Engineering, Kindai University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan
| | - Kyona Hiroshima
- Faculty of Science and Engineering, Kindai University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan
| | - Toru Kawakami
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Kaeko Murota
- Faculty of Life and Environmental Sciences, Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690-8504, Japan
| | - Shigeru Shimamoto
- Faculty of Science and Engineering, Kindai University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan
- Correspondence: (S.S.); (Y.H.); Tel.: +81-6-6721-2332 (S.S.)
| | - Yuji Hidaka
- Faculty of Science and Engineering, Kindai University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan
- Correspondence: (S.S.); (Y.H.); Tel.: +81-6-6721-2332 (S.S.)
| |
Collapse
|
5
|
Zalem D, Juhás M, Terrinoni M, King-Lyons N, Lebens M, Varrot A, Connell TD, Teneberg S. Characterization of the ganglioside recognition profile of Escherichia coli heat-labile enterotoxin LT-IIc. Glycobiology 2022; 32:391-403. [PMID: 34972864 PMCID: PMC9022906 DOI: 10.1093/glycob/cwab133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 11/23/2021] [Accepted: 12/19/2021] [Indexed: 11/14/2022] Open
Abstract
The heat-labile enterotoxins of Escherichia coli and cholera toxin of Vibrio cholerae are related in structure and function. Each of these oligomeric toxins is comprised of one A polypeptide and five B polypeptides. The B-subunits bind to gangliosides, which are followed by uptake into the intoxicated cell and activation of the host's adenylate cyclase by the A-subunits. There are two antigenically distinct groups of these toxins. Group I includes cholera toxin and type I heat-labile enterotoxin of E. coli; group II contains the type II heat-labile enterotoxins of E. coli. Three variants of type II toxins, designated LT-IIa, LT-IIb and LT-IIc have been described. Earlier studies revealed the crystalline structure of LT-IIb. Herein the carbohydrate binding specificity of LT-IIc B-subunits was investigated by glycosphingolipid binding studies on thin-layer chromatograms and in microtiter wells. Binding studies using a large variety of glycosphingolipids showed that LT-IIc binds with high affinity to gangliosides with a terminal Neu5Acα3Gal or Neu5Gcα3Gal, e.g. the gangliosides GM3, GD1a and Neu5Acα3-/Neu5Gcα3--neolactotetraosylceramide and Neu5Acα3-/Neu5Gcα3-neolactohexaosylceramide. The crystal structure of LT-IIc B-subunits alone and with bound LSTd/sialyl-lacto-N-neotetraose d pentasaccharide uncovered the molecular basis of the ganglioside recognition. These studies revealed common and unique functional structures of the type II family of heat-labile enterotoxins.
Collapse
Affiliation(s)
- Dani Zalem
- Department of Medical Biochemistry and Cell Biology, Sahlgrenska Academy, Institute of Biomedicine, University of Gothenburg, Sweden
| | - Martin Juhás
- Department of Medical Biochemistry and Cell Biology, Sahlgrenska Academy, Institute of Biomedicine, University of Gothenburg, Sweden
- Department of Pharmaceutical Chemistry and Pharmaceutical Analysis, Charles University, Faculty of Pharmacy in Hradec Králové, Akademika Heyrovského 1203, Hradec Králové 500 05, Czech Republic
| | - Manuela Terrinoni
- Department of Microbiology and Immunology, Sahlgrenska Academy, Institute of Biomedicine, University of Gothenburg, Sweden
| | - Natalie King-Lyons
- Department of Microbiology & Immunology and The Witebsky Center for Microbial Pathogenesis and Immunology, The Jacobs School of Medicine and Biomedical Sciences, The University at Buffalo, State University of New York, Buffalo, NY 14203, USA
| | - Michael Lebens
- Department of Microbiology and Immunology, Sahlgrenska Academy, Institute of Biomedicine, University of Gothenburg, Sweden
| | | | - Terry D Connell
- Department of Microbiology & Immunology and The Witebsky Center for Microbial Pathogenesis and Immunology, The Jacobs School of Medicine and Biomedical Sciences, The University at Buffalo, State University of New York, Buffalo, NY 14203, USA
| | - Susann Teneberg
- Department of Medical Biochemistry and Cell Biology, Sahlgrenska Academy, Institute of Biomedicine, University of Gothenburg, Sweden
| |
Collapse
|
6
|
Xiao X, Sarma S, Menegatti S, Crook N, Magness ST, Hall CK. In Silico Identification and Experimental Validation of Peptide-Based Inhibitors Targeting Clostridium difficile Toxin A. ACS Chem Biol 2022; 17:118-128. [PMID: 34965093 DOI: 10.1021/acschembio.1c00743] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Clostridium difficile infection is mediated by two major exotoxins: toxins A (TcdA) and B (TcdB). Inhibiting the biocatalytic activities of these toxins with targeted peptide-based drugs can reduce the risk of C. difficile infection. In this work, we used a computational strategy that integrates a peptide binding design (PepBD) algorithm and explicit-solvent atomistic molecular dynamics simulation to determine promising toxin A-targeting peptides that can recognize and bind to the catalytic site of the TcdA glucosyltransferase domain (GTD). Our simulation results revealed that two out of three in silico discovered peptides, viz. the neutralizing peptides A (NPA) and B (NPB), exhibit lower binding free energies when bound to the TcdA GTD than the phage-display discovered peptide, viz. the reference peptide (RP). These peptides may serve as potential inhibitors against C. difficile infection. The efficacy of the peptides RP, NPA, and NPB to neutralize the cytopathic effects of TcdA was tested in vitro in human jejunum cells. Both phage-display peptide RP and in silico peptide NPA were found to exhibit strong toxin-neutralizing properties, thereby preventing the TcdA toxicity. However, the in silico peptide NPB demonstrates a relatively low efficacy against TcdA.
Collapse
Affiliation(s)
- Xingqing Xiao
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Sudeep Sarma
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Stefano Menegatti
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
- Biomanufacturing Training and Education Center (BTEC), North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Nathan Crook
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Scott T Magness
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514, United States
| | - Carol K Hall
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| |
Collapse
|
7
|
Aminzadeh A, Larsen CE, Boesen T, Jørgensen R. High-resolution structure of native toxin A from Clostridioides difficile. EMBO Rep 2022; 23:e53597. [PMID: 34817920 PMCID: PMC8728606 DOI: 10.15252/embr.202153597] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 11/09/2021] [Accepted: 11/10/2021] [Indexed: 01/07/2023] Open
Abstract
Clostridioides difficile infections have emerged as the leading cause of healthcare-associated infectious diarrhea. Disease symptoms are mainly caused by the virulence factors, TcdA and TcdB, which are large homologous multidomain proteins. Here, we report a 2.8 Å resolution cryo-EM structure of native TcdA, unveiling its conformation at neutral pH. The structure uncovers the dynamic movement of the CROPs domain which is induced in response to environmental acidification. Furthermore, the structure reveals detailed information about the interaction area between the CROPs domain and the tip of the delivery and receptor-binding domain, which likely serves to shield the C-terminal part of the hydrophobic pore-forming region from solvent exposure. Similarly, extensive interactions between the globular subdomain and the N-terminal part of the pore-forming region suggest that the globular subdomain shields the upper part of the pore-forming region from exposure to the surrounding solvent. Hence, the TcdA structure provides insights into the mechanism of preventing premature unfolding of the pore-forming region at neutral pH, as well as the pH-induced inter-domain dynamics.
Collapse
Affiliation(s)
- Aria Aminzadeh
- Department of Bacteria, Parasites and FungiStatens Serum InstitutCopenhagenDenmark
| | - Christian Engelbrecht Larsen
- Interdisciplinary Nanoscience Center (iNANO)Aarhus UniversityAarhusDenmark
- Department of Molecular Biology and GeneticsAarhus UniversityAarhusDenmark
| | - Thomas Boesen
- Interdisciplinary Nanoscience Center (iNANO)Aarhus UniversityAarhusDenmark
- Department of Molecular Biology and GeneticsAarhus UniversityAarhusDenmark
| | - René Jørgensen
- Department of Bacteria, Parasites and FungiStatens Serum InstitutCopenhagenDenmark
- Department of Science and EnvironmentUniversity of RoskildeRoskildeDenmark
| |
Collapse
|
8
|
Hoffmann P, Burmester M, Langeheine M, Brehm R, Empl MT, Seeger B, Breves G. Caco-2/HT29-MTX co-cultured cells as a model for studying physiological properties and toxin-induced effects on intestinal cells. PLoS One 2021; 16:e0257824. [PMID: 34618824 PMCID: PMC8496855 DOI: 10.1371/journal.pone.0257824] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 09/12/2021] [Indexed: 12/28/2022] Open
Abstract
Infectious gastrointestinal diseases are frequently caused by toxins secreted by pathogens which may impair physiological functions of the intestines, for instance by cholera toxin or by heat-labile enterotoxin. To obtain a functional model of the human intestinal epithelium for studying toxin-induced disease mechanisms, differentiated enterocyte-like Caco-2 cells were co-cultured with goblet cell-like HT29-MTX cells. These co-cultures formed a functional epithelial barrier, as characterized by a high electrical resistance and the presence of physiological intestinal properties such as glucose transport and chloride secretion which could be demonstrated electrophysiologically and by measuring protein expression. When the tissues were exposed to cholera toxin or heat-labile enterotoxin in the Ussing chamber, cholera toxin incubation resulted in an increase in short-circuit currents, indicating an increase in apical chloride secretion. This is in line with typical cholera toxin-induced secretory diarrhea in humans, while heat-labile enterotoxin only showed an increase in short-circuit-current in Caco-2 cells. This study characterizes for the first time the simultaneous measurement of physiological properties on a functional and structural level combined with the epithelial responses to bacterial toxins. In conclusion, using this model, physiological responses of the intestine to bacterial toxins can be investigated and characterized. Therefore, this model can serve as an alternative to the use of laboratory animals for characterizing pathophysiological mechanisms of enterotoxins at the intestinal level.
Collapse
Affiliation(s)
- Pascal Hoffmann
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Marion Burmester
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Marion Langeheine
- Institute for Anatomy, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Ralph Brehm
- Institute for Anatomy, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Michael T. Empl
- Institute for Food Toxicology, University of Veterinary Medicine, Hannover, Germany
| | - Bettina Seeger
- Institute for Food Toxicology, University of Veterinary Medicine, Hannover, Germany
| | - Gerhard Breves
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, Hannover, Germany
| |
Collapse
|
9
|
Abeyawardhane DL, Godoy-Ruiz R, Adipietro KA, Varney KM, Rustandi RR, Pozharski E, Weber DJ. The Importance of Therapeutically Targeting the Binary Toxin from Clostridioides difficile. Int J Mol Sci 2021; 22:2926. [PMID: 33805767 PMCID: PMC8001090 DOI: 10.3390/ijms22062926] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 03/03/2021] [Accepted: 03/09/2021] [Indexed: 02/06/2023] Open
Abstract
Novel therapeutics are needed to treat pathologies associated with the Clostridioides difficile binary toxin (CDT), particularly when C. difficile infection (CDI) occurs in the elderly or in hospitalized patients having illnesses, in addition to CDI, such as cancer. While therapies are available to block toxicities associated with the large clostridial toxins (TcdA and TcdB) in this nosocomial disease, nothing is available yet to treat toxicities arising from strains of CDI having the binary toxin. Like other binary toxins, the active CDTa catalytic subunit of CDT is delivered into host cells together with an oligomeric assembly of CDTb subunits via host cell receptor-mediated endocytosis. Once CDT arrives in the host cell's cytoplasm, CDTa catalyzes the ADP-ribosylation of G-actin leading to degradation of the cytoskeleton and rapid cell death. Although a detailed molecular mechanism for CDT entry and host cell toxicity is not yet fully established, structural and functional resemblances to other binary toxins are described. Additionally, unique conformational assemblies of individual CDT components are highlighted herein to refine our mechanistic understanding of this deadly toxin as is needed to develop effective new therapeutic strategies for treating some of the most hypervirulent and lethal strains of CDT-containing strains of CDI.
Collapse
Affiliation(s)
- Dinendra L. Abeyawardhane
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (D.L.A.); (R.G.-R.); (K.A.A.); (K.M.V.); (E.P.)
- Baltimore—Institute for Bioscience and Biotechnology Research, University of Maryland-Institute for Bioscience and Biotechnology Research, Rockville, MD 20850, USA
- The Center for Biomolecular Therapeutics, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Raquel Godoy-Ruiz
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (D.L.A.); (R.G.-R.); (K.A.A.); (K.M.V.); (E.P.)
- Baltimore—Institute for Bioscience and Biotechnology Research, University of Maryland-Institute for Bioscience and Biotechnology Research, Rockville, MD 20850, USA
- The Center for Biomolecular Therapeutics, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Kaylin A. Adipietro
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (D.L.A.); (R.G.-R.); (K.A.A.); (K.M.V.); (E.P.)
- The Center for Biomolecular Therapeutics, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Kristen M. Varney
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (D.L.A.); (R.G.-R.); (K.A.A.); (K.M.V.); (E.P.)
- Baltimore—Institute for Bioscience and Biotechnology Research, University of Maryland-Institute for Bioscience and Biotechnology Research, Rockville, MD 20850, USA
- The Center for Biomolecular Therapeutics, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | | | - Edwin Pozharski
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (D.L.A.); (R.G.-R.); (K.A.A.); (K.M.V.); (E.P.)
- Baltimore—Institute for Bioscience and Biotechnology Research, University of Maryland-Institute for Bioscience and Biotechnology Research, Rockville, MD 20850, USA
- The Center for Biomolecular Therapeutics, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - David J. Weber
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (D.L.A.); (R.G.-R.); (K.A.A.); (K.M.V.); (E.P.)
- Baltimore—Institute for Bioscience and Biotechnology Research, University of Maryland-Institute for Bioscience and Biotechnology Research, Rockville, MD 20850, USA
- The Center for Biomolecular Therapeutics, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| |
Collapse
|
10
|
Torres JB, Mosley M, Koustoulidou S, Hopkins S, Knapp S, Chaikuad A, Kondoh M, Tachibana K, Kersemans V, Cornelissen B. Radiolabeled cCPE Peptides for SPECT Imaging of Claudin-4 Overexpression in Pancreatic Cancer. J Nucl Med 2020; 61:1756-1763. [PMID: 32414951 PMCID: PMC8679629 DOI: 10.2967/jnumed.120.243113] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 04/16/2020] [Indexed: 01/09/2023] Open
Abstract
Overexpression of tight-junction protein claudin-4 has been detected in primary and metastatic pancreatic cancer tissue and is associated with better prognosis in patients. Noninvasive measurement of claudin-4 expression by imaging methods could provide a means for accelerating detection and stratifying patients into risk groups. Clostridium perfringens enterotoxin (CPE) is a natural ligand for claudin-4 and holds potential as a targeting vector for molecular imaging of claudin-4 overexpression. A glutathione S-transferases (GST)-tagged version of the C terminus of CPE (cCPE) was previously used to delineate claudin-4 overexpression by SPECT but showed modest binding affinity and slow blood clearance in vivo. Methods: On the basis of the crystal structure of cCPE, a series of smaller cCPE194-319 mutants with putatively improved binding affinity for claudin-4 was generated by site-directed mutagenesis. All peptides were conjugated site-specifically on a C-terminal cysteine using maleimide-diethylenetriamine pentaacetate to enable radiolabeling with 111In. The binding affinity of all radioconjugates was evaluated in claudin-4-expressing PSN-1 cells and HT1080-negative controls. The specificity of all cCPE mutants to claudin-4 was assessed in HT1080 cells stably transfected with claudin-4. SPECT/CT imaging of BALB/c nude mice bearing PSN-1 or HT1080 tumor xenografts was performed to determine the claudin-4-targeting ability of these peptides in vivo. Results: Uptake of all cCPE-based radioconjugates was significantly higher in PSN-1 cells than in HT1080-negative controls. All peptides showed a marked improvement in affinity for claudin-4 in vitro when compared with previously reported values (dissociation constant: 2.2 ± 0.8, 3 ± 0.1, 4.2 ± 0.5, 10 ± 0.9, and 9.7 ± 0.7 nM). Blood clearance of [111In]In-cCPE194-319, as measured by SPECT, was considerably faster than that of [111In]In-cCPE.GST (half-life, <1 min). All radiopeptides showed significantly higher accumulation in PSN-1 xenografts than in HT1080 tumors at 90 min after injection of the tracer ([111In]In-cCPE194-319, 2.7 ± 0.8 vs. 0.4 ± 0.1 percentage injected dose per gram [%ID/g], P < 0.001; [111In]In-S313A, 2.3 ± 0.9 vs. 0.5 ± 0.1 %ID/g, P < 0.01; [111In]In-S307A + N309A + S313A, 2 ± 0.4 vs. 0.3 ± 0.1 %ID/g, P < 0.01; [111In]In-D284A, 2 ± 0.2 vs. 0.7 ± 0.1 %ID/g, P < 0.05; [111In]In-L254F + K257D, 6.3 ± 0.9 vs. 0.7 ± 0.2 %ID/g, P < 0.001). Conclusion: These optimized cCPE-based SPECT imaging agents show great promise as claudin-4-targeting vectors for in vivo imaging of claudin-4 overexpression in pancreatic cancer.
Collapse
Affiliation(s)
- Julia Baguña Torres
- Cancer Research United Kingdom and Medical Research Council Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Michael Mosley
- Cancer Research United Kingdom and Medical Research Council Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Sofia Koustoulidou
- Cancer Research United Kingdom and Medical Research Council Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Samantha Hopkins
- Cancer Research United Kingdom and Medical Research Council Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Stefan Knapp
- Institute of Pharmaceutical Chemistry and Structure Genomics Consortium, Goethe-University Frankfurt, Frankfurt am Main, Germany
- German Cancer Network, Mainz-Frankfurt, Germany; and
| | - Apirat Chaikuad
- Institute of Pharmaceutical Chemistry and Structure Genomics Consortium, Goethe-University Frankfurt, Frankfurt am Main, Germany
| | - Masuo Kondoh
- Graduate School of Pharmaceutical Sciences, Osaka University, Yamadaoka, Suita, Osaka, Japan
| | - Keisuke Tachibana
- Graduate School of Pharmaceutical Sciences, Osaka University, Yamadaoka, Suita, Osaka, Japan
| | - Veerle Kersemans
- Cancer Research United Kingdom and Medical Research Council Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Bart Cornelissen
- Cancer Research United Kingdom and Medical Research Council Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| |
Collapse
|
11
|
Oliveira Paiva AM, de Jong L, Friggen AH, Smits WK, Corver J. The C-Terminal Domain of Clostridioides difficile TcdC Is Exposed on the Bacterial Cell Surface. J Bacteriol 2020; 202:JB.00771-19. [PMID: 32868401 PMCID: PMC7585056 DOI: 10.1128/jb.00771-19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 08/25/2020] [Indexed: 02/04/2023] Open
Abstract
Clostridioides difficile is an anaerobic Gram-positive bacterium that can produce the large clostridial toxins toxin A and toxin B, encoded within the pathogenicity locus (PaLoc). The PaLoc also encodes the sigma factor TcdR, which positively regulates toxin gene expression, and TcdC, which is a putative negative regulator of toxin expression. TcdC is proposed to be an anti-sigma factor; however, several studies failed to show an association between the tcdC genotype and toxin production. Consequently, the TcdC function is not yet fully understood. Previous studies have characterized TcdC as a membrane-associated protein with the ability to bind G-quadruplex structures. The binding to the DNA secondary structures is mediated through the oligonucleotide/oligosaccharide binding fold (OB-fold) domain present at the C terminus of the protein. This domain was previously also proposed to be responsible for the inhibitory effect on toxin gene expression, implicating a cytoplasmic localization of the OB-fold. In this study, we aimed to obtain topological information on the C terminus of TcdC and demonstrate that the C terminus of TcdC is located extracellularly. In addition, we show that the membrane association of TcdC is dependent on a membrane-proximal cysteine residue and that mutating this residue results in the release of TcdC from the bacterial cell. The extracellular location of TcdC is not compatible with the direct binding of the OB-fold domain to intracellular nucleic acid or protein targets and suggests a mechanism of action that is different from that of the characterized anti-sigma factors.IMPORTANCE The transcription of C. difficile toxins TcdA and TcdB is directed by the sigma factor TcdR. TcdC has been proposed to be an anti-sigma factor. The activity of TcdC has been mapped to its C terminus, and the N terminus serves as the membrane anchor. Acting as an anti-sigma factor requires a cytoplasmic localization of the C terminus of TcdC. Using cysteine accessibility analysis and a HiBiT-based system, we show that the TcdC C terminus is located extracellularly, which is incompatible with its role as anti-sigma factor. Furthermore, mutating a cysteine residue at position 51 resulted in the release of TcdC from the bacteria. The codon-optimized version of the HiBiT (HiBiTopt) extracellular detection system is a valuable tool for topology determination of membrane proteins, increasing the range of systems available to tackle important aspects of C. difficile development.
Collapse
Affiliation(s)
- Ana M Oliveira Paiva
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, The Netherlands
- Center for Microbial Cell Biology, Leiden, The Netherlands
| | - Leen de Jong
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, The Netherlands
| | - Annemieke H Friggen
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, The Netherlands
- Center for Microbial Cell Biology, Leiden, The Netherlands
| | - Wiep Klaas Smits
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, The Netherlands
- Center for Microbial Cell Biology, Leiden, The Netherlands
| | - Jeroen Corver
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, The Netherlands
| |
Collapse
|
12
|
Etter D, Schelin J, Schuppler M, Johler S. Staphylococcal Enterotoxin C-An Update on SEC Variants, Their Structure and Properties, and Their Role in Foodborne Intoxications. Toxins (Basel) 2020; 12:E584. [PMID: 32927913 PMCID: PMC7551944 DOI: 10.3390/toxins12090584] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/07/2020] [Accepted: 09/08/2020] [Indexed: 12/20/2022] Open
Abstract
Staphylococcal enterotoxins are the most common cause of foodborne intoxications (staphylococcal food poisoning) and cause a wide range of diseases. With at least six variants staphylococcal enterotoxin C (SEC) stands out as particularly diverse amongst the 25 known staphylococcal enterotoxins. Some variants present unique and even host-specific features. Here, we review the role of SEC in human and animal health with a particular focus on its role as a causative agent for foodborne intoxications. We highlight structural features unique to SEC and its variants, particularly, the emetic and superantigen activity, as well as the roles of SEC in mastitis and in dairy products. Information about the genetic organization as well as regulatory mechanisms including the accessory gene regulator and food-related stressors are provided.
Collapse
Affiliation(s)
- Danai Etter
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zürich, 8057 Zürich, Switzerland;
- Laboratory of Food Microbiology, Institute of Food, Nutrition and Health, ETH Zürich, 8092 Zürich, Switzerland;
| | - Jenny Schelin
- Division of Applied Microbiology, Department of Chemistry, Lund University, 22100 Lund, Sweden;
| | - Markus Schuppler
- Laboratory of Food Microbiology, Institute of Food, Nutrition and Health, ETH Zürich, 8092 Zürich, Switzerland;
| | - Sophia Johler
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zürich, 8057 Zürich, Switzerland;
| |
Collapse
|
13
|
Abstract
Aeromonas exotoxin A (AE) is a bacterial virulence factor recently discovered in a clinical case of necrotising fasciitis caused by the flesh-eating Aeromonas hydrophila. Here, database mining shows that AE is present in the genome of several emerging Aeromonas pathogenic species. The X-ray crystal structure of AE was solved at 2.3 Å and presents all the hallmarks common to diphthamide-specific mono-ADP-ribosylating toxins, suggesting AE is a fourth member of this family alongside the diphtheria toxin, Pseudomonas exotoxin A and cholix. Structural homology indicates AE may use a similar mechanism of cytotoxicity that targets eukaryotic elongation factor 2 and thus inhibition of protein synthesis. The structure of AE also highlights unique features including a metal binding site, and a negatively charged cleft that could play a role in interdomain interactions and may affect toxicity. This study raises new opportunities to engineer alternative toxin-based molecules with pharmaceutical potential.
Collapse
Affiliation(s)
- Geoffrey Masuyer
- Department of Pharmacy and Pharmacology, Centre for Therapeutic Innovation, University of Bath, Bath BA2 7AY, UK
| |
Collapse
|
14
|
Sasaki T, Mori S, Kishi S, Fujiwara-Tani R, Ohmori H, Nishiguchi Y, Hojo Y, Kawahara I, Nakashima C, Fujii K, Luo Y, Kuniyasu H. Effect of Proton Pump Inhibitors on Colorectal Cancer. Int J Mol Sci 2020; 21:ijms21113877. [PMID: 32485921 PMCID: PMC7312442 DOI: 10.3390/ijms21113877] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 05/19/2020] [Accepted: 05/20/2020] [Indexed: 02/07/2023] Open
Abstract
Proton pump inhibitors (PPIs) are administered commonly to aged people; however, their effect on colorectal cancer (CRC) has still not been fully elucidated. Here, we examined the effect of PPIs and consequent alkalization on CRC cells. PPI administration alkalized the fecal pH and increased serum gastrin concentration. PPI and pH8 treatment (alkalization) of CMT93 mouse colon cancer cells inhibited cell growth and invasion, increased oxidative stress and apoptosis, and decreased mitochondrial volume and protein levels of cyclin D1 and phosphorylated extracellular signal-regulated kinase (pERK) 1/2. In contrast, gastrin treatment enhanced growth and invasion, decreased oxidative stress and apoptosis, and increased mitochondrial volume and cyclin D1 and pERK1/2 levels. Concurrent treatment with a PPI, pH8, and gastrin increased aldehyde dehydrogenase activity and also enhanced liver metastasis in the BALB/c strain of mice. PPI administration was associated with Clostridiumperfringens enterotoxin (CPE) in CRC lesions. CPE treatment activated yes-associated protein (YAP) signals to enhance proliferation and stemness. The orthotopic colon cancer model of CMT93 cells with long-term PPI administration showed enhanced tumor growth and liver metastasis due to gastrin and YAP activation, as indicated by gastrin receptor knockdown and treatment with a YAP inhibitor. These findings suggest that PPI promotes CRC growth and metastasis by increasing gastrin concentration and YAP activation, resulting in gut flora alteration and fecal alkalization. These findings suggest that PPI use in colorectal cancer patients might create a risk of cancer promotion.
Collapse
Affiliation(s)
- Takamitsu Sasaki
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara 634-8521, Japan; (T.S.); (S.M.); (S.K.); (R.F.-T.); (H.O.); (Y.N.); (Y.H.); (I.K.); (C.N.); (K.F.)
| | - Shiori Mori
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara 634-8521, Japan; (T.S.); (S.M.); (S.K.); (R.F.-T.); (H.O.); (Y.N.); (Y.H.); (I.K.); (C.N.); (K.F.)
| | - Shingo Kishi
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara 634-8521, Japan; (T.S.); (S.M.); (S.K.); (R.F.-T.); (H.O.); (Y.N.); (Y.H.); (I.K.); (C.N.); (K.F.)
| | - Rina Fujiwara-Tani
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara 634-8521, Japan; (T.S.); (S.M.); (S.K.); (R.F.-T.); (H.O.); (Y.N.); (Y.H.); (I.K.); (C.N.); (K.F.)
| | - Hitoshi Ohmori
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara 634-8521, Japan; (T.S.); (S.M.); (S.K.); (R.F.-T.); (H.O.); (Y.N.); (Y.H.); (I.K.); (C.N.); (K.F.)
| | - Yukiko Nishiguchi
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara 634-8521, Japan; (T.S.); (S.M.); (S.K.); (R.F.-T.); (H.O.); (Y.N.); (Y.H.); (I.K.); (C.N.); (K.F.)
| | - Yudai Hojo
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara 634-8521, Japan; (T.S.); (S.M.); (S.K.); (R.F.-T.); (H.O.); (Y.N.); (Y.H.); (I.K.); (C.N.); (K.F.)
| | - Isao Kawahara
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara 634-8521, Japan; (T.S.); (S.M.); (S.K.); (R.F.-T.); (H.O.); (Y.N.); (Y.H.); (I.K.); (C.N.); (K.F.)
| | - Chie Nakashima
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara 634-8521, Japan; (T.S.); (S.M.); (S.K.); (R.F.-T.); (H.O.); (Y.N.); (Y.H.); (I.K.); (C.N.); (K.F.)
| | - Kiyomu Fujii
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara 634-8521, Japan; (T.S.); (S.M.); (S.K.); (R.F.-T.); (H.O.); (Y.N.); (Y.H.); (I.K.); (C.N.); (K.F.)
| | - Yi Luo
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China
- Correspondence: (Y.L.); (H.K.); Tel.: +86-0513-85051805 (Y.L.); +81-744-22-3051 (H.K.); Fax: +81-744-25-7308 (H.K.)
| | - Hiroki Kuniyasu
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara 634-8521, Japan; (T.S.); (S.M.); (S.K.); (R.F.-T.); (H.O.); (Y.N.); (Y.H.); (I.K.); (C.N.); (K.F.)
- Correspondence: (Y.L.); (H.K.); Tel.: +86-0513-85051805 (Y.L.); +81-744-22-3051 (H.K.); Fax: +81-744-25-7308 (H.K.)
| |
Collapse
|
15
|
Fujiwara-Tani R, Fujii K, Mori S, Kishi S, Sasaki T, Ohmori H, Nakashima C, Kawahara I, Nishiguchi Y, Mori T, Sho M, Kondoh M, Luo Y, Kuniyasu H. Role of Clostridium perfringens Enterotoxin on YAP Activation in Colonic Sessile Serrated Adenoma/ Polyps with Dysplasia. Int J Mol Sci 2020; 21:ijms21113840. [PMID: 32481659 PMCID: PMC7313056 DOI: 10.3390/ijms21113840] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 05/26/2020] [Accepted: 05/26/2020] [Indexed: 12/11/2022] Open
Abstract
Sessile serrated adenoma/polyp with dysplasia (SSA/P-D) is an SSA/P with cellular dysplasia and has a higher risk of progressing to colon carcinogenesis. Previously, we reported that tight junction impairment by Clostridiumperfringens enterotoxin (CPE) leads to activation of the transcriptional co-activator yes-associated protein (YAP) in oral squamous cell carcinoma. Here, we investigated whether CPE activates YAP to promote the malignant progression of SSA/P. E-cadherin expression was lower in the 12 cases with SSA/P-D examined than that in normal mucosa, SSA/P, or tubular adenoma (TA). Furthermore, intracellular translocation of claudin-4 (CLDN4) and nuclear translocation of YAP were observed. The CPE gene was detected in DNA extracted from SSA/P-D lesions, but not in SSA/P or TA. Treatment of the rat intestinal epithelial cell line IEC6 with low-dose CPE resulted in intracellular translocation of CLDN4 to the cytoplasmic membrane. Cytoplasmic CLDN4 showed co-precipitation with transcriptional co-activator with PDZ-binding motif, zonula occludens (ZO)-1, large tumor suppressor, and mammalian Ste20-like. Additionally, YAP co-precipitated with ZO-2 under CPE treatment led to decreased YAP phosphorylation and nuclear translocation. YAP activation promoted increase in nuclear TEA domain family member level, expression of cyclin D1, snail, vimentin, CD44, NS and decrease in E-cadherin levels, thereby inducing stemness and epithelial-mesenchymal-transition (EMT). The Hippo complex with the incorporation of CLDN4 increased stability. Upon low-dose CPE treatment, HT29 cells with BRAFV600E gene mutation showed increased growth, enhanced invasive potential, stemness, and induced EMT phenotype, whereas HCT116 cells, which carry KRASG13D gene mutation, did not show such changes. In an examination of 10 colorectal cancers, an increase in EMT and stemness was observed in CPE (+) and BRAF mutation (+) cases. These findings suggest that C.perfringens might enhance the malignant transformation of SSA/P-D via YAP activation. Our findings further highlight the importance of controlling intestinal flora using probiotics or antibiotics.
Collapse
Affiliation(s)
- Rina Fujiwara-Tani
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521, Japan; (R.F.-T.); (K.F.); (S.M.); (S.K.); (T.S.); (H.O.); (C.N.); (I.K.); (Y.N.); (T.M.)
| | - Kiyomu Fujii
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521, Japan; (R.F.-T.); (K.F.); (S.M.); (S.K.); (T.S.); (H.O.); (C.N.); (I.K.); (Y.N.); (T.M.)
| | - Shiori Mori
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521, Japan; (R.F.-T.); (K.F.); (S.M.); (S.K.); (T.S.); (H.O.); (C.N.); (I.K.); (Y.N.); (T.M.)
| | - Shingo Kishi
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521, Japan; (R.F.-T.); (K.F.); (S.M.); (S.K.); (T.S.); (H.O.); (C.N.); (I.K.); (Y.N.); (T.M.)
| | - Takamitsu Sasaki
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521, Japan; (R.F.-T.); (K.F.); (S.M.); (S.K.); (T.S.); (H.O.); (C.N.); (I.K.); (Y.N.); (T.M.)
| | - Hitoshi Ohmori
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521, Japan; (R.F.-T.); (K.F.); (S.M.); (S.K.); (T.S.); (H.O.); (C.N.); (I.K.); (Y.N.); (T.M.)
| | - Chie Nakashima
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521, Japan; (R.F.-T.); (K.F.); (S.M.); (S.K.); (T.S.); (H.O.); (C.N.); (I.K.); (Y.N.); (T.M.)
| | - Isao Kawahara
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521, Japan; (R.F.-T.); (K.F.); (S.M.); (S.K.); (T.S.); (H.O.); (C.N.); (I.K.); (Y.N.); (T.M.)
| | - Yukiko Nishiguchi
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521, Japan; (R.F.-T.); (K.F.); (S.M.); (S.K.); (T.S.); (H.O.); (C.N.); (I.K.); (Y.N.); (T.M.)
| | - Takuya Mori
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521, Japan; (R.F.-T.); (K.F.); (S.M.); (S.K.); (T.S.); (H.O.); (C.N.); (I.K.); (Y.N.); (T.M.)
| | - Masayuki Sho
- Department of Surgery, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8522, Japan;
| | - Masuo Kondoh
- Drug Innovation Center, Graduate School of Pharmaceutical Sciences, Osaka University, 6-1 Yamadaoka, Suita, Osaka 565-0871, Japan;
| | - Yi Luo
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong 226001, Jiangsu Province, China
- Correspondence: (Y.L.); (H.K.); Tel.: +86-0513-8505-1805 (Y.L.); +81-744-22-3051 (H.K.); Fax: +81-744-25-7308 (H.K.)
| | - Hiroki Kuniyasu
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521, Japan; (R.F.-T.); (K.F.); (S.M.); (S.K.); (T.S.); (H.O.); (C.N.); (I.K.); (Y.N.); (T.M.)
- Correspondence: (Y.L.); (H.K.); Tel.: +86-0513-8505-1805 (Y.L.); +81-744-22-3051 (H.K.); Fax: +81-744-25-7308 (H.K.)
| |
Collapse
|
16
|
Xu X, Godoy-Ruiz R, Adipietro KA, Peralta C, Ben-Hail D, Varney KM, Cook ME, Roth BM, Wilder PT, Cleveland T, Grishaev A, Neu HM, Michel SLJ, Yu W, Beckett D, Rustandi RR, Lancaster C, Loughney JW, Kristopeit A, Christanti S, Olson JW, MacKerell AD, Georges AD, Pozharski E, Weber DJ. Structure of the cell-binding component of the Clostridium difficile binary toxin reveals a di-heptamer macromolecular assembly. Proc Natl Acad Sci U S A 2020; 117:1049-1058. [PMID: 31896582 PMCID: PMC6969506 DOI: 10.1073/pnas.1919490117] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Targeting Clostridium difficile infection is challenging because treatment options are limited, and high recurrence rates are common. One reason for this is that hypervirulent C. difficile strains often have a binary toxin termed the C. difficile toxin, in addition to the enterotoxins TsdA and TsdB. The C. difficile toxin has an enzymatic component, termed CDTa, and a pore-forming or delivery subunit termed CDTb. CDTb was characterized here using a combination of single-particle cryoelectron microscopy, X-ray crystallography, NMR, and other biophysical methods. In the absence of CDTa, 2 di-heptamer structures for activated CDTb (1.0 MDa) were solved at atomic resolution, including a symmetric (SymCDTb; 3.14 Å) and an asymmetric form (AsymCDTb; 2.84 Å). Roles played by 2 receptor-binding domains of activated CDTb were of particular interest since the receptor-binding domain 1 lacks sequence homology to any other known toxin, and the receptor-binding domain 2 is completely absent in other well-studied heptameric toxins (i.e., anthrax). For AsymCDTb, a Ca2+ binding site was discovered in the first receptor-binding domain that is important for its stability, and the second receptor-binding domain was found to be critical for host cell toxicity and the di-heptamer fold for both forms of activated CDTb. Together, these studies represent a starting point for developing structure-based drug-design strategies to target the most severe strains of C. difficile.
Collapse
Affiliation(s)
- Xingjian Xu
- City University of New York Advanced Science Research Center, City University of New York, New York, NY 10017
- PhD Program in Biochemistry, The Graduate Center, City University of New York, New York, NY 10017
| | - Raquel Godoy-Ruiz
- Department of Biochemistry & Molecular Biology, University of Maryland School of Medicine, University of Maryland, Baltimore, MD 21201
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
- The Center for Biomolecular Therapeutics, The University of Maryland School of Medicine, University of Maryland, Baltimore, MD 21201
| | - Kaylin A Adipietro
- Department of Biochemistry & Molecular Biology, University of Maryland School of Medicine, University of Maryland, Baltimore, MD 21201
- The Center for Biomolecular Therapeutics, The University of Maryland School of Medicine, University of Maryland, Baltimore, MD 21201
| | - Christopher Peralta
- City University of New York Advanced Science Research Center, City University of New York, New York, NY 10017
| | - Danya Ben-Hail
- City University of New York Advanced Science Research Center, City University of New York, New York, NY 10017
| | - Kristen M Varney
- Department of Biochemistry & Molecular Biology, University of Maryland School of Medicine, University of Maryland, Baltimore, MD 21201
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
- The Center for Biomolecular Therapeutics, The University of Maryland School of Medicine, University of Maryland, Baltimore, MD 21201
| | - Mary E Cook
- Department of Biochemistry & Molecular Biology, University of Maryland School of Medicine, University of Maryland, Baltimore, MD 21201
- The Center for Biomolecular Therapeutics, The University of Maryland School of Medicine, University of Maryland, Baltimore, MD 21201
| | - Braden M Roth
- Department of Biochemistry & Molecular Biology, University of Maryland School of Medicine, University of Maryland, Baltimore, MD 21201
| | - Paul T Wilder
- Department of Biochemistry & Molecular Biology, University of Maryland School of Medicine, University of Maryland, Baltimore, MD 21201
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
- The Center for Biomolecular Therapeutics, The University of Maryland School of Medicine, University of Maryland, Baltimore, MD 21201
| | | | | | - Heather M Neu
- University of Maryland School of Pharmacy, University of Maryland, Baltimore, MD 21201
| | - Sarah L J Michel
- University of Maryland School of Pharmacy, University of Maryland, Baltimore, MD 21201
| | - Wenbo Yu
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
- The Center for Biomolecular Therapeutics, The University of Maryland School of Medicine, University of Maryland, Baltimore, MD 21201
- University of Maryland School of Pharmacy, University of Maryland, Baltimore, MD 21201
| | - Dorothy Beckett
- Department of Chemistry & Biochemistry, University of Maryland, College Park, MD 20742
| | | | | | | | | | | | | | - Alexander D MacKerell
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
- The Center for Biomolecular Therapeutics, The University of Maryland School of Medicine, University of Maryland, Baltimore, MD 21201
- University of Maryland School of Pharmacy, University of Maryland, Baltimore, MD 21201
| | - Amedee des Georges
- City University of New York Advanced Science Research Center, City University of New York, New York, NY 10017;
- PhD Program in Biochemistry, The Graduate Center, City University of New York, New York, NY 10017
- PhD Program in Chemistry, The Graduate Center, City University of New York, New York, NY 10017
- Department of Chemistry & Biochemistry, City College of New York, New York, NY 10031
| | - Edwin Pozharski
- Department of Biochemistry & Molecular Biology, University of Maryland School of Medicine, University of Maryland, Baltimore, MD 21201;
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
- The Center for Biomolecular Therapeutics, The University of Maryland School of Medicine, University of Maryland, Baltimore, MD 21201
| | - David J Weber
- Department of Biochemistry & Molecular Biology, University of Maryland School of Medicine, University of Maryland, Baltimore, MD 21201;
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
- The Center for Biomolecular Therapeutics, The University of Maryland School of Medicine, University of Maryland, Baltimore, MD 21201
| |
Collapse
|
17
|
Piontek A, Eichner M, Zwanziger D, Beier L, Protze J, Walther W, Theurer S, Schmid KW, Führer‐Sakel D, Piontek J, Krause G. Targeting claudin-overexpressing thyroid and lung cancer by modified Clostridium perfringens enterotoxin. Mol Oncol 2020; 14:261-276. [PMID: 31825142 PMCID: PMC6998413 DOI: 10.1002/1878-0261.12615] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 10/22/2019] [Accepted: 12/09/2019] [Indexed: 01/04/2023] Open
Abstract
Clostridium perfringens enterotoxin (CPE) can be used to eliminate carcinoma cells that overexpress on their cell surface CPE receptors - a subset of claudins (e.g., Cldn3 and Cldn4). However, CPE cannot target tumors expressing solely CPE-insensitive claudins (such as Cldn1 and Cldn5). To overcome this limitation, structure-guided modifications were used to generate CPE variants that can strongly bind to Cldn1, Cldn2 and/or Cldn5, while maintaining the ability to bind Cldn3 and Cldn4. This enabled (a) targeting of the most frequent endocrine malignancy, namely, Cldn1-overexpressing thyroid cancer, and (b) improved targeting of the most common cancer type worldwide, non-small-cell lung cancer (NSCLC), which is characterized by high expression of several claudins, including Cldn1 and Cldn5. Different CPE variants, including the novel mutant CPE-Mut3 (S231R/S313H), were applied on thyroid cancer (K1 cells) and NSCLC (PC-9 cells) models. In vitro, CPE-Mut3, but not CPEwt, showed Cldn1-dependent binding and cytotoxicity toward K1 cells. For PC-9 cells, CPE-Mut3 improved claudin-dependent cytotoxic targeting, when compared to CPEwt. In vivo, intratumoral injection of CPE-Mut3 in xenograft models bearing K1 or PC-9 tumors induced necrosis and reduced the growth of both tumor types. Thus, directed modification of CPE enables eradication of tumor entities that cannot be targeted by CPEwt, for instance, Cldn1-overexpressing thyroid cancer by using the novel CPE-Mut3.
Collapse
Affiliation(s)
- Anna Piontek
- Leibniz‐Forschungsinstitut für Molekulare Pharmakologie (FMP)BerlinGermany
| | - Miriam Eichner
- Institute of Clinical Physiology / Nutritional Medicine, Medical DepartmentDivision of Gastroenterology, Infectiology, Rheumatology, Charitè – Universitätsmedizin BerlinGermany
| | - Denise Zwanziger
- Department of Endocrinology, Diabetes and Metabolism and Clinical Chemistry – Division of Laboratory ResearchUniversity Hospital EssenGermany
| | - Laura‐Sophie Beier
- Institute of Clinical Physiology / Nutritional Medicine, Medical DepartmentDivision of Gastroenterology, Infectiology, Rheumatology, Charitè – Universitätsmedizin BerlinGermany
| | - Jonas Protze
- Leibniz‐Forschungsinstitut für Molekulare Pharmakologie (FMP)BerlinGermany
| | - Wolfgang Walther
- Experimental and Clinical Research CenterCharitè and Max‐Delbrück‐Center for Molecular MedicineBerlinGermany
| | - Sarah Theurer
- Institute of PathologyUniversity Hospital EssenGermany
| | | | - Dagmar Führer‐Sakel
- Department of Endocrinology, Diabetes and Metabolism and Clinical Chemistry – Division of Laboratory ResearchUniversity Hospital EssenGermany
| | - Jörg Piontek
- Institute of Clinical Physiology / Nutritional Medicine, Medical DepartmentDivision of Gastroenterology, Infectiology, Rheumatology, Charitè – Universitätsmedizin BerlinGermany
| | - Gerd Krause
- Leibniz‐Forschungsinstitut für Molekulare Pharmakologie (FMP)BerlinGermany
| |
Collapse
|
18
|
Loiseau A, Zhang L, Hu D, Salmain M, Mazouzi Y, Flack R, Liedberg B, Boujday S. Core-Shell Gold/Silver Nanoparticles for Localized Surface Plasmon Resonance-Based Naked-Eye Toxin Biosensing. ACS Appl Mater Interfaces 2019; 11:46462-46471. [PMID: 31744295 DOI: 10.1021/acsami.9b14980] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The localized surface plasmon resonance (LSPR) phenomenon provides a versatile property for biodetection. Herein, this unique feature was employed to build a homogeneous optical biosensor to detect staphylococcal enterotoxin A (SEA) in solution down to very low levels by naked-eye readout. If the initial position of the LSPR band is located in the cyan region, even a small red shift (∼2-3 nm) induced by a refractive index change close to the surface of nanoparticles (NPs) could make the light absorption transit from cyan to green and become visually detectable via a concomitant change in the complementary colors. In this work, we aimed at synthesizing two types of NPs based on compositionally complex core-shell NPs-Ag shells on AuNPs (Au@AgNPs) and Ag inside gold nanoshells (Ag@AuNPs). By controlling the thickness of the shells and their surface chemistry with anti-SEA antibody (Ab), the LSPR band was tuned to near 495 and 520 nm for Ag@AuNPs and Au@AgNPs, respectively. The two particle systems were subsequently applied to spectroscopically and visually detect anti-SEA Ab-SEA interactions. Upon the addition of SEA, large red shifts of the LSPR band were observed spectroscopically and the limits of detection (LODs) were estimated to be 0.2 and 0.4 nM for Au@AgNPs and Ag@AuNPs, respectively. Although the two sets of NPs gave almost identical LODs, the Ag@AuNPs whose initial position of the LSPR band was tuned in the cyan to green region (∼500 nm) displayed a substantially more distinct color change from orange to red, as revealed by the naked eye. We foresee significant potential to this strategy in medical diagnostics and environmental monitoring, especially when basic laboratory infrastructure is sparse or nonexistent.
Collapse
Affiliation(s)
- Alexis Loiseau
- Sorbonne Université, CNRS, Laboratoire de Réactivité de Surface (LRS) , 4 Place Jussieu , F 75005 Paris , France
| | - Lu Zhang
- Sorbonne Université, CNRS, Laboratoire de Réactivité de Surface (LRS) , 4 Place Jussieu , F 75005 Paris , France
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire (IPCM) , 4 Place Jussieu , F 75005 Paris , France
- Centre for Biomimetic Sensor Science, School of Materials Science and Engineering , Nanyang Technological University , Singapore 637553 , Singapore
| | - David Hu
- Sorbonne Université, CNRS, Laboratoire de Réactivité de Surface (LRS) , 4 Place Jussieu , F 75005 Paris , France
| | - Michèle Salmain
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire (IPCM) , 4 Place Jussieu , F 75005 Paris , France
| | - Yacine Mazouzi
- Sorbonne Université, CNRS, Laboratoire de Réactivité de Surface (LRS) , 4 Place Jussieu , F 75005 Paris , France
| | - Raphaël Flack
- Sorbonne Université, CNRS, Laboratoire de Réactivité de Surface (LRS) , 4 Place Jussieu , F 75005 Paris , France
| | - Bo Liedberg
- Centre for Biomimetic Sensor Science, School of Materials Science and Engineering , Nanyang Technological University , Singapore 637553 , Singapore
| | - Souhir Boujday
- Sorbonne Université, CNRS, Laboratoire de Réactivité de Surface (LRS) , 4 Place Jussieu , F 75005 Paris , France
| |
Collapse
|
19
|
Zeng C, Liu Z, Han Z. Structure of Staphylococcal Enterotoxin N: Implications for Binding Properties to Its Cellular Proteins. Int J Mol Sci 2019; 20:ijms20235921. [PMID: 31775346 PMCID: PMC6928602 DOI: 10.3390/ijms20235921] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 11/20/2019] [Accepted: 11/22/2019] [Indexed: 01/26/2023] Open
Abstract
Staphylococcus aureus strains produce a unique family of immunostimulatory exotoxins termed as bacterial superantigens (SAgs), which cross-link major histocompatibility complex class II (MHC II) molecule and T-cell receptor (TCR) to stimulate large numbers of T cells at extremely low concentrations. SAgs are associated with food poisoning and toxic shock syndrome. To date, 26 genetically distinct staphylococcal SAgs have been reported. This study reports the first X-ray structure of newly characterized staphylococcal enterotoxin N (SEN). SEN possesses the classical two domain architecture that includes an N-terminal oligonucleotide-binding fold and a C-terminal β-grasp domain. Amino acid and structure alignments revealed that several critical amino acids that are proposed to be responsible for MHC II and TCR molecule engagements are variable in SEN, suggesting that SEN may adopt a different binding mode to its cellular receptors. This work helps better understand the mechanisms of action of SAgs.
Collapse
Affiliation(s)
- Chi Zeng
- College of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan 430023, China; (C.Z.); (Z.L.)
- Hubei Province Fresh Food Engineering Research Center, Wuhan Polytechnic University, Wuhan 430023, China
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture), Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan 430064, China
| | - Zhaoxin Liu
- College of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan 430023, China; (C.Z.); (Z.L.)
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Zhenggang Han
- College of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan 430023, China; (C.Z.); (Z.L.)
- Correspondence:
| |
Collapse
|
20
|
Ono HK, Hachiya N, Suzuki Y, Naito I, Hirose S, Asano K, Omoe K, Nakane A, Hu DL. Development of an Immunoassay for Detection of Staphylococcal Enterotoxin-Like J, A Non-Characterized Toxin. Toxins (Basel) 2018; 10:toxins10110458. [PMID: 30404173 PMCID: PMC6266802 DOI: 10.3390/toxins10110458] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 10/22/2018] [Accepted: 11/03/2018] [Indexed: 11/16/2022] Open
Abstract
Staphylococcal enterotoxins (SEs) are the cause of staphylococcal food poisoning (SFP) outbreaks. Recently, many new types of SEs and SE-like toxins have been reported, but it has not been proved whether these new toxins cause food poisoning. To develop an immunoassay for detection of SE-like J (SElJ), a non-characterized toxin in SFP, a mutant SElJ with C-terminus deletion (SElJ∆C) was expressed and purified in an E. coli expression system. Anti-SElJ antibody was produced in rabbits immunized with the SElJ∆C. Western blotting and sandwich enzyme-linked immunosorbent assay (ELISA) detection systems were established and showed that the antibody specifically recognizes SElJ without cross reaction to other SEs tested. The limit of detection for the sandwich ELISA was 0.078 ng/mL, showing high sensitivity. SElJ production in S. aureus was detected by using the sandwich ELISA and showed that selj-horboring isolates produced a large amount of SElJ in the culture supernatants, especially in that of the strain isolated from a food poisoning outbreak in Japan. These results demonstrate that the immunoassay for detection of SElJ is specific and sensitive and is useful for determining the native SElJ production in S. aureus isolated from food poisoning cases.
Collapse
Affiliation(s)
- Hisaya K Ono
- Department of Zoonoses, Kitasato University School of Veterinary Medicine, 35-1 Higashi-23-ban-cho, Towada, Aomori 034-8628, Japan.
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan.
| | - Nobuaki Hachiya
- Department of Zoonoses, Kitasato University School of Veterinary Medicine, 35-1 Higashi-23-ban-cho, Towada, Aomori 034-8628, Japan.
| | - Yasunori Suzuki
- Department of Microbiology, Tokyo Metropolitan Institute of Public Health, Shinjuku-ku, Tokyo 169-0073, Japan.
| | - Ikunori Naito
- Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Ueda 3-18-8, Morioka, Iwate 020-8550, Japan.
| | - Shouhei Hirose
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan.
| | - Krisana Asano
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan.
| | - Katsuhiko Omoe
- Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Ueda 3-18-8, Morioka, Iwate 020-8550, Japan.
| | - Akio Nakane
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan.
| | - Dong-Liang Hu
- Department of Zoonoses, Kitasato University School of Veterinary Medicine, 35-1 Higashi-23-ban-cho, Towada, Aomori 034-8628, Japan.
| |
Collapse
|
21
|
Löser R, Bader M, Kuchar M, Wodtke R, Lenk J, Wodtke J, Kuhne K, Bergmann R, Haase-Kohn C, Urbanová M, Steinbach J, Pietzsch J. Synthesis, 18F-labelling and radiopharmacological characterisation of the C-terminal 30mer of Clostridium perfringens enterotoxin as a potential claudin-targeting peptide. Amino Acids 2018; 51:219-244. [PMID: 30264172 DOI: 10.1007/s00726-018-2657-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 09/17/2018] [Indexed: 12/26/2022]
Abstract
The cell surface receptor claudin-4 (Cld-4) is upregulated in various tumours and represents an important emerging target for both diagnosis and treatment of solid tumours of epithelial origin. The C-terminal fragment of the Clostridium perfringens enterotoxin cCPE290-319 appears as a suitable ligand for targeting Cld-4. The synthesis of this 30mer peptide was attempted via several approaches, which has revealed sequential SPPS using three pseudoproline dipeptide building blocks to be the most efficient one. Labelling with fluorine-18 was achieved on solid phase using N-succinimidyl 4-[18F]fluorobenzoate ([18F]SFB) and 4-[18F]fluorobenzoyl chloride as 18F-acylating agents, which was the most advantageous when [18F]SFB was reacted with the resin-bound 30mer containing an N-terminal 6-aminohexanoic spacer. Binding to Cld-4 was demonstrated via surface plasmon resonance using a protein construct containing both extracellular loops of Cld-4. In addition, cell binding experiments were performed for 18F-labelled cCPE290-319 with the Cld-4 expressing tumour cell lines HT-29 and A431 that were complemented by fluorescence microscopy studies using the corresponding fluorescein isothiocyanate-conjugated peptide. The 30mer peptide proved to be sufficiently stable in blood plasma. Studying the in vivo behaviour of 18F-labelled cCPE290-319 in healthy mice and rats by dynamic PET imaging and radiometabolite analyses has revealed that the peptide is subject to substantial liver uptake and rapid metabolic degradation in vivo, which limits its suitability as imaging probe for tumour-associated Cld-4.
Collapse
Affiliation(s)
- Reik Löser
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany.
- Faculty of Chemistry and Food Chemistry, School of Science, Technische Universität Dresden, Mommsenstraße 4, 01062, Dresden, Germany.
| | - Miriam Bader
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany
- Faculty of Chemistry and Food Chemistry, School of Science, Technische Universität Dresden, Mommsenstraße 4, 01062, Dresden, Germany
| | - Manuela Kuchar
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany
- Faculty of Chemistry and Food Chemistry, School of Science, Technische Universität Dresden, Mommsenstraße 4, 01062, Dresden, Germany
| | - Robert Wodtke
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany
- Faculty of Chemistry and Food Chemistry, School of Science, Technische Universität Dresden, Mommsenstraße 4, 01062, Dresden, Germany
| | - Jens Lenk
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany
- Faculty of Chemistry and Food Chemistry, School of Science, Technische Universität Dresden, Mommsenstraße 4, 01062, Dresden, Germany
| | - Johanna Wodtke
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany
| | - Konstantin Kuhne
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany
- Faculty of Chemistry and Food Chemistry, School of Science, Technische Universität Dresden, Mommsenstraße 4, 01062, Dresden, Germany
| | - Ralf Bergmann
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany
| | - Cathleen Haase-Kohn
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany
| | - Marie Urbanová
- Department of Physics and Measurements, University of Chemistry and Technology, 166 28, Prague, Czech Republic
| | - Jörg Steinbach
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany
- Faculty of Chemistry and Food Chemistry, School of Science, Technische Universität Dresden, Mommsenstraße 4, 01062, Dresden, Germany
| | - Jens Pietzsch
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany
- Faculty of Chemistry and Food Chemistry, School of Science, Technische Universität Dresden, Mommsenstraße 4, 01062, Dresden, Germany
| |
Collapse
|
22
|
Ortega-Berlanga B, Bañuelos-Hernández B, Rosales-Mendoza S. Efficient Expression of an Alzheimer's Disease Vaccine Candidate in the Microalga Schizochytrium sp. Using the Algevir System. Mol Biotechnol 2018; 60:362-368. [PMID: 29594986 DOI: 10.1007/s12033-018-0077-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disease, where β-amyloid (Aβ) plays a key role in forming conglomerated senile plaques. The receptor of advanced glycation end products (RAGE) is considered a therapeutic target since it transports Aβ into the central nervous system, favoring the pathology progression. Due to the lack of effective therapies for AD, several therapeutic approaches are under development, being vaccines considered a promising alternative. Herein, the use of the Algevir system was explored to produce in the Schizochytrium sp. microalga the LTB:RAGE vaccine candidate. Algevir relies in an inducible geminiviral vector and led to yields of up to 380 µg LTB:RAGE/g fresh weight biomass at 48-h post-induction. The Schizochytrium-produced LTB:RAGE vaccine retained its antigenic activity and was highly stable up to temperatures of 60 °C. These data demonstrate the potential of Schizochytrium sp. as a platform for high production of thermostable recombinant antigens useful for vaccination against AD.
Collapse
Affiliation(s)
- Benita Ortega-Berlanga
- Laboratorio de Biofarmacéuticos Recombinantes, Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, Av. Dr. Manuel Nava 6, 78210, San Luis Potosí, SLP, Mexico
- Sección de Biotecnología, Centro de Investigación en Ciencias de la Salud y Biomedicina, Universidad Autónoma de San Luis Potosí, Av. Dr. Manuel Nava 6, 78210, San Luis Potosí, SLP, Mexico
| | - Bernardo Bañuelos-Hernández
- Laboratorio de Biofarmacéuticos Recombinantes, Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, Av. Dr. Manuel Nava 6, 78210, San Luis Potosí, SLP, Mexico
- Sección de Biotecnología, Centro de Investigación en Ciencias de la Salud y Biomedicina, Universidad Autónoma de San Luis Potosí, Av. Dr. Manuel Nava 6, 78210, San Luis Potosí, SLP, Mexico
| | - Sergio Rosales-Mendoza
- Laboratorio de Biofarmacéuticos Recombinantes, Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, Av. Dr. Manuel Nava 6, 78210, San Luis Potosí, SLP, Mexico.
- Sección de Biotecnología, Centro de Investigación en Ciencias de la Salud y Biomedicina, Universidad Autónoma de San Luis Potosí, Av. Dr. Manuel Nava 6, 78210, San Luis Potosí, SLP, Mexico.
| |
Collapse
|
23
|
Huang J, Duan Q, Zhang W. Significance of Enterotoxigenic Escherichia coli (ETEC) Heat-Labile Toxin (LT) Enzymatic Subunit Epitopes in LT Enterotoxicity and Immunogenicity. Appl Environ Microbiol 2018; 84:e00849-18. [PMID: 29802193 PMCID: PMC6052278 DOI: 10.1128/aem.00849-18] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 05/19/2018] [Indexed: 01/28/2023] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) strains producing heat-labile toxin (LT) and/or heat-stable toxin (STa) are a top cause of children's diarrhea and travelers' diarrhea. Holotoxin-structured GM1-binding LT is a strong immunogen and an effective adjuvant, and can serve a carrier or a platform for multivalent vaccine development. However, the significance of peptide domains or epitopes of LT particularly enzymatic LTA subunit in association with LT enterotoxicity and immunogenicity has not been characterized. In this study, we identified B-cell epitopes in silico from LTA subunit and examined epitopes for immunogenicity and association with LT enterotoxicity. Epitopes identified from LTA subunit were individually fused to a modified chicken ovalbumin carrier protein, and each epitope-ovalbumin fusion was used to immunize mice. Data showed all 11 LTA epitopes were immunogenic; epitope 7 (105SPHPYEQEVSA115) induced greater titers of anti-LT antibodies which neutralized LT enterotoxicity more effectively. To examine these epitopes for the significance in LT enterotoxicity, we constructed LT mutants by substituting each of 10 epitopes at the toxic A1 domain of LTA subunit with a foreign epitope and examined LT mutants for enterotoxicity and GM1-binding activity. Data showed that LT mutants exhibited no enterotoxicity but retained GM1-binding activity. The results from this study indicated that while not all immunodominant LTA epitopes were neutralizing, LT mutants with an individual epitope substituted lost enterotoxicity but retained GM1-binding activity. These results provided additional information to understand LT immunogenicity and enterotoxicity and suggested the potential application of LT platform for multivalent vaccines against ETEC diarrhea and other diseases.IMPORTANCE No vaccine is licensed for enterotoxigenic Escherichia coli (ETEC) strains, which remain a leading cause of diarrhea in children from developing countries and international travelers. GM1-binding heat-labile toxin (LT) which is a key virulence factor of ETEC diarrhea is a strong vaccine antigen and a self-adjuvant. LT can also serve a backbone or platform for MEFA (multiepitope fusion antigen), a newly developed structural vaccinology technology, to present heterogeneous epitopes (by replacing LT epitopes) and to mimic epitope antigenicity for development of broadly protective vaccines. Data from this study identified neutralizing LT epitopes and demonstrated that substitution of LT epitopes eliminated LT enterotoxicity without altering GM1-binding activity, suggesting LT is potentially a versatile MEFA platform to present heterogeneous epitopes for multivalent vaccines against ETEC and other pathogens.
Collapse
Affiliation(s)
- Jiachen Huang
- Department of Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, USA
| | - Qiangde Duan
- Department of Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, USA
| | - Weiping Zhang
- Department of Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, USA
| |
Collapse
|
24
|
Jeong WH, Song DH, Hur GH, Jeong ST. Structure of the staphylococcal enterotoxin B vaccine candidate S19 showing eliminated superantigen activity. Acta Crystallogr F Struct Biol Commun 2017; 73:595-600. [PMID: 29095152 PMCID: PMC5683028 DOI: 10.1107/s2053230x17014844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 10/13/2017] [Indexed: 11/29/2022] Open
Abstract
Four mutations (N23A, Y90A, R110A and F177A) were introduced into S19, a vaccine candidate for staphylococcal enterotoxin B (SEB), resulting in a lower binding affinity towards the T-cell receptor beta chain (TCB) and reducing its superantigen activity. The structure of S19 was solved and was superposed on the native or complex structure of SEB. In the superposition model, mutations that were introduced seemed to reduce the number of hydrogen bonds at the SEB-TCB interface. S19 also displayed an unexpected structural change around the flexible-loop region owing to the Y90A mutation. This local structural change provided evidence that the mutated form of S19 could have a lower affinity for major histocompatibility complex (MHC) class II than wild-type SEB.
Collapse
Affiliation(s)
- Woo Hyeon Jeong
- The 5th R&D Institute, Agency for Defense Development, Yuseong PO Box 35, Yuseong-gu, Daejeon 34188, Republic of Korea
| | - Dong Hyun Song
- The 5th R&D Institute, Agency for Defense Development, Yuseong PO Box 35, Yuseong-gu, Daejeon 34188, Republic of Korea
| | - Gyeung Haeng Hur
- The 5th R&D Institute, Agency for Defense Development, Yuseong PO Box 35, Yuseong-gu, Daejeon 34188, Republic of Korea
| | - Seong Tae Jeong
- The 5th R&D Institute, Agency for Defense Development, Yuseong PO Box 35, Yuseong-gu, Daejeon 34188, Republic of Korea
| |
Collapse
|
25
|
Toprani VM, Sahni N, Hickey JM, Robertson GA, Middaugh CR, Joshi SB, Volkin DB. Development of a candidate stabilizing formulation for bulk storage of a double mutant heat labile toxin (dmLT) protein based adjuvant. Vaccine 2017; 35:5471-5480. [PMID: 28551040 PMCID: PMC5628956 DOI: 10.1016/j.vaccine.2017.03.101] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 03/15/2017] [Accepted: 03/31/2017] [Indexed: 11/27/2022]
Abstract
This work describes the formulation design and development of a novel protein based adjuvant, a double mutant of heat labile toxin (dmLT), based on knowledge of the protein's structural integrity and physicochemical degradation pathways. Various classes of pharmaceutical excipients were screened for their stabilizing effect on dmLT during exposure to thermal and agitation stresses as monitored by high throughput analytical assays for dmLT degradation. Sucrose, phosphate, sodium chloride, methionine and polysorbate-80 were identified as potential stabilizers that protected dmLT against either conformational destabilization, aggregation/particle formation or chemical degradation (e.g., Met oxidation and Lys glycation). Different combinations and concentrations of the selected stabilizers were then evaluated to further optimize dmLT stability while maintaining pharmaceutically acceptable ranges of solution pH and osmolality. The effect of multiple freeze-thaw (FT) cycles on the physical stability of candidate bulk formulations was also examined. Increasing the polysorbate-80 concentration to 0.1% in the lead candidate bulk formulation mitigated the loss of protein mass during FT. This formulation development study enabled the design of a new bulk formulation of the dmLT adjuvant and provides flexibility for future use in combination with a variety of different vaccine dosage forms with different antigens.
Collapse
Affiliation(s)
- Vishal M Toprani
- Department of Pharmaceutical Chemistry, Macromolecule and Vaccine Stabilization Center, University of Kansas, 2030 Becker Drive, Lawrence, KS 66047, USA
| | - Neha Sahni
- Department of Pharmaceutical Chemistry, Macromolecule and Vaccine Stabilization Center, University of Kansas, 2030 Becker Drive, Lawrence, KS 66047, USA
| | - John M Hickey
- Department of Pharmaceutical Chemistry, Macromolecule and Vaccine Stabilization Center, University of Kansas, 2030 Becker Drive, Lawrence, KS 66047, USA
| | - George A Robertson
- The Center for Vaccine Innovation and Access, PATH, 455 Massachusetts Ave NW Suite 1000, Washington, DC 20001, USA
| | - C Russell Middaugh
- Department of Pharmaceutical Chemistry, Macromolecule and Vaccine Stabilization Center, University of Kansas, 2030 Becker Drive, Lawrence, KS 66047, USA
| | - Sangeeta B Joshi
- Department of Pharmaceutical Chemistry, Macromolecule and Vaccine Stabilization Center, University of Kansas, 2030 Becker Drive, Lawrence, KS 66047, USA
| | - David B Volkin
- Department of Pharmaceutical Chemistry, Macromolecule and Vaccine Stabilization Center, University of Kansas, 2030 Becker Drive, Lawrence, KS 66047, USA.
| |
Collapse
|
26
|
Hatlem D, Heggelund JE, Burschowsky D, Krengel U, Kristiansen PE. 1H, 13C, 15N backbone assignment of the human heat-labile enterotoxin B-pentamer and chemical shift mapping of neolactotetraose binding. Biomol NMR Assign 2017; 11:99-104. [PMID: 28243889 DOI: 10.1007/s12104-017-9728-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 02/16/2017] [Indexed: 06/06/2023]
Abstract
The major virulence factor of enterotoxigenic Escherichia coli is the heat-labile enterotoxin (LT), an AB5 toxin closely related to the cholera toxin. LT consists of six subunits, the catalytically active A-subunit and five B-subunits arranged as a pentameric ring (LTB), which enable the toxin to bind to the epithelial cells in the intestinal lumen. LTB has two recognized binding sites; the primary binding site is responsible for anchoring the toxin to its main receptor, the GM1-ganglioside, while the secondary binding site recognizes blood group antigens. Herein, we report the 1H, 13C, 15N main chain assignment of LTB from human isolates (hLTB; 103 a.a. per subunit, with a total molecular mass of 58.5 kDa). The secondary structure was predicted based on 13C', 13Cα, 13Cβ, 1HN and 15N chemical shifts and compared to a published crystal structure of LTB. Neolactotetraose (NEO) was titrated to hLTB and chemical shift perturbations were measured. The chemical shift perturbations were mapped onto the crystal structure, confirming that NEO binds to the primary binding site of hLTB and competes with GM1-binding. Our new data further lend support to the hypothesis that binding at the primary binding site is transmitted to the secondary binding site of the toxin, where it may influence the binding to blood group antigens.
Collapse
Affiliation(s)
- Daniel Hatlem
- Department of Chemistry, University of Oslo, Blindern, P.O. Box 1033, 0315, Oslo, Norway
- Department of Biosciences, University of Oslo, Blindern, P.O. Box 1066, 0316, Oslo, Norway
| | - Julie E Heggelund
- Department of Chemistry, University of Oslo, Blindern, P.O. Box 1033, 0315, Oslo, Norway
- School of Pharmacy, University of Oslo, Blindern, P.O. Box 1068, 0316, Oslo, Norway
| | - Daniel Burschowsky
- Department of Chemistry, University of Oslo, Blindern, P.O. Box 1033, 0315, Oslo, Norway
- Department of Molecular and Cell Biology, University of Leicester, University Road, Leicester, LE1 7RH, UK
| | - Ute Krengel
- Department of Chemistry, University of Oslo, Blindern, P.O. Box 1033, 0315, Oslo, Norway.
| | - Per E Kristiansen
- Department of Biosciences, University of Oslo, Blindern, P.O. Box 1066, 0316, Oslo, Norway.
| |
Collapse
|
27
|
Chatterjee S, Neill R, Shupp JW, Hammamieh R, Ionin B, Jett M. Identification of Staphylococcal Enterotoxin B Domains Involved in Binding to Cultured Human Kidney Proximal Tubular Cells: Imparting Proliferation and Death. Exp Biol Med (Maywood) 2016; 232:1142-51. [PMID: 17895522 DOI: 10.3181/0609-rm-245] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Studies suggest that staphylococcal enterotoxin B (SEB) is initially harbored in the kidney by binding to digalactosylceramide molecules in the proximal tubular cells. However, little is known in regard to the peptide motif within SEB that binds to these cells and imparts toxic effects. Herein, using human kidney proximal tubular cells (PTs) we have performed a systematic study on the binding of various peptides and peptide analogs of SEB and demonstrate a structure-functional relationship. Using [125I]labeled SEB peptides, we show a high affinity and displaceable binding of SEB 191–220 to human PT cells. Binding was mitigated by the use of antibody against SEB, by digalactosylceramide (the putative receptor), and by the use of endoglycoceramidase, which selectively removes the oligosaccharide backbones from glycosphingolipids. Our structure/ functional studies revealed that peptide 130–160 induces a concentration-dependent increase in programmed cell death/ apoptosis in human proximal tubular cells. Mechanistic studies further suggest that SEB/SEB peptide (130–160) impart apoptosis via the activation of neutral sphingomyelinase, which hydrolizes sphingomyelin to ceramide and phosphocholine. SEB 130–160 mediated apoptosis was mitigated by preincubation of cells with antibody against SEB and an SEB 130–160 antibody.
Collapse
Affiliation(s)
- Subroto Chatterjee
- Department of Pediatrics, Johns Hopkins University, Baltimore, Maryland 21205, USA.
| | | | | | | | | | | |
Collapse
|
28
|
Pattison AM, Merlino DJ, Blomain ES, Waldman SA. Guanylyl cyclase C signaling axis and colon cancer prevention. World J Gastroenterol 2016; 22:8070-8077. [PMID: 27688649 PMCID: PMC5037076 DOI: 10.3748/wjg.v22.i36.8070] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 06/25/2016] [Accepted: 08/01/2016] [Indexed: 02/06/2023] Open
Abstract
Colorectal cancer (CRC) is a major cause of cancer-related mortality and morbidity worldwide. While improved treatments have enhanced overall patient outcome, disease burden encompassing quality of life, cost of care, and patient survival has seen little benefit. Consequently, additional advances in CRC treatments remain important, with an emphasis on preventative measures. Guanylyl cyclase C (GUCY2C), a transmembrane receptor expressed on intestinal epithelial cells, plays an important role in orchestrating intestinal homeostatic mechanisms. These effects are mediated by the endogenous hormones guanylin (GUCA2A) and uroguanylin (GUCA2B), which bind and activate GUCY2C to regulate proliferation, metabolism and barrier function in intestine. Recent studies have demonstrated a link between GUCY2C silencing and intestinal dysfunction, including tumorigenesis. Indeed, GUCY2C silencing by the near universal loss of its paracrine hormone ligands increases colon cancer susceptibility in animals and humans. GUCY2C’s role as a tumor suppressor has opened the door to a new paradigm for CRC prevention by hormone replacement therapy using synthetic hormone analogs, such as the FDA-approved oral GUCY2C ligand linaclotide (Linzess™). Here we review the known contributions of the GUCY2C signaling axis to CRC, and relate them to a novel clinical strategy targeting tumor chemoprevention.
Collapse
|
29
|
Liu D, Guo H, Zheng W, Zhang N, Wang T, Wang P, Ma X. Discovery of the cell-penetrating function of A2 domain derived from LTA subunit of Escherichia coli heat-labile enterotoxin. Appl Microbiol Biotechnol 2016; 100:5079-88. [PMID: 26960316 DOI: 10.1007/s00253-016-7423-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 02/21/2016] [Accepted: 02/24/2016] [Indexed: 10/22/2022]
Abstract
Heat-labile enterotoxin (LT) is a protein toxin produced by enterotoxigenic Escherichia coli (ETEC). As a bacterial toxin, LT holotoxin can enter intestinal epithelial cells and cause diarrhea. In addition, LT is also a powerful mucosal adjuvant capable of enhancing the strong immune responses to co-administered antigens. However, the LT immunological mechanism is still not clear in some aspects, especially with the respect to how the LTA subunit functions alone. Here, we discovered that the A2 domain of LTA could carry a fluorescent protein into cells, whose function is similar to a cell-penetrating peptide. The transmembrane-transporting ability of the A2 domain is non-specific in its cell-penetrating function, which was shown through testing with different cell types. Moreover, the LTA2 fusion protein penetrated a fluorescently labeled cell membrane that identified LTA2 internalization through membrane transport pathways, and showed it finally localized in the endoplasmic reticulum. Furthermore, low-temperature stress and pharmacological agent treatments showed that the LTA2 internalization route is a temperature-dependent process involving the clathrin-mediated endocytosis and the macropinocytosis pathways. These results could explain the internalization of the LTA subunit alone without the LTB pentamer, contributing to a better understanding of LTA working as a mucosal adjuvant; they also suggest that the A2 domain could be used as a novel transport vehicle for research and treatment of disease.
Collapse
Affiliation(s)
- Di Liu
- School of Biotechnology and State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Hua Guo
- School of Biotechnology and State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Wenyun Zheng
- School of Pharmacy, Shanghai Key Laboratory of New Drug Design, East China University of Science and Technology, Shanghai, China
| | - Na Zhang
- School of Biotechnology and State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Tianwen Wang
- School of Biotechnology and State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Ping Wang
- School of Biotechnology and State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Xingyuan Ma
- School of Biotechnology and State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China.
| |
Collapse
|
30
|
Di Bella S, Ascenzi P, Siarakas S, Petrosillo N, di Masi A. Clostridium difficile Toxins A and B: Insights into Pathogenic Properties and Extraintestinal Effects. Toxins (Basel) 2016; 8:toxins8050134. [PMID: 27153087 PMCID: PMC4885049 DOI: 10.3390/toxins8050134] [Citation(s) in RCA: 147] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 04/22/2016] [Accepted: 04/25/2016] [Indexed: 02/06/2023] Open
Abstract
Clostridium difficile infection (CDI) has significant clinical impact especially on the elderly and/or immunocompromised patients. The pathogenicity of Clostridium difficile is mainly mediated by two exotoxins: toxin A (TcdA) and toxin B (TcdB). These toxins primarily disrupt the cytoskeletal structure and the tight junctions of target cells causing cell rounding and ultimately cell death. Detectable C. difficile toxemia is strongly associated with fulminant disease. However, besides the well-known intestinal damage, recent animal and in vitro studies have suggested a more far-reaching role for these toxins activity including cardiac, renal, and neurologic impairment. The creation of C. difficile strains with mutations in the genes encoding toxin A and B indicate that toxin B plays a major role in overall CDI pathogenesis. Novel insights, such as the role of a regulator protein (TcdE) on toxin production and binding interactions between albumin and C. difficile toxins, have recently been discovered and will be described. Our review focuses on the toxin-mediated pathogenic processes of CDI with an emphasis on recent studies.
Collapse
Affiliation(s)
- Stefano Di Bella
- 2nd Infectious Diseases Division, National Institute for Infectious Diseases "L. Spallanzani", Rome 00149, Italy.
| | - Paolo Ascenzi
- Department of Science, Roma Tre University, Rome 00154, Italy.
| | - Steven Siarakas
- Department of Microbiology and Infectious Diseases, Concord Repatriation General Hospital, Sydney 2139, Australia.
| | - Nicola Petrosillo
- 2nd Infectious Diseases Division, National Institute for Infectious Diseases "L. Spallanzani", Rome 00149, Italy.
| | | |
Collapse
|
31
|
Tobias J, Von Mentzer A, Loayza Frykberg P, Aslett M, Page AJ, Sjöling Å, Svennerholm AM. Stability of the Encoding Plasmids and Surface Expression of CS6 Differs in Enterotoxigenic Escherichia coli (ETEC) Encoding Different Heat-Stable (ST) Enterotoxins (STh and STp). PLoS One 2016; 11:e0152899. [PMID: 27054573 PMCID: PMC4824445 DOI: 10.1371/journal.pone.0152899] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 03/21/2016] [Indexed: 12/01/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC), one of the most common reasons of diarrhea among infants and children in developing countries, causes disease by expression of either or both of the enterotoxins heat-labile (LT) and heat-stable (ST; divided into human-type [STh] and porcine-type [STp] variants), and colonization factors (CFs) among which CS6 is one of the most prevalent ETEC CFs. In this study we show that ETEC isolates expressing CS6+STh have higher copy numbers of the cssABCD operon encoding CS6 than those expressing CS6+STp. Long term cultivation of up to ten over-night passages of ETEC isolates harboring CS6+STh (n = 10) or CS6+STp (n = 15) showed instability of phenotypic expression of CS6 in a majority of the CS6+STp isolates, whereas most of the CS6+STh isolates retained CS6 expression. The observed instability was a correlated with loss of genes cssA and cssD as examined by PCR. Mobilization of the CS6 plasmid from an unstable CS6+STp isolate into a laboratory E. coli strain resulted in loss of the plasmid after a single over-night passage whereas the plasmid from an CS6+STh strain was retained in the laboratory strain during 10 passages. A sequence comparison between the CS6 plasmids from a stable and an unstable ETEC isolate revealed that genes necessary for plasmid stabilization, for example pemI, pemK, stbA, stbB and parM, were not present in the unstable ETEC isolate. Our results indicate that stable retention of CS6 may in part be affected by the stability of the plasmid on which both CS6 and STp or STh are located.
Collapse
Affiliation(s)
- Joshua Tobias
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, S-40530, Göteborg, Sweden
- * E-mail:
| | - Astrid Von Mentzer
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, S-40530, Göteborg, Sweden
| | - Patricia Loayza Frykberg
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, S-40530, Göteborg, Sweden
| | - Martin Aslett
- Pathogen Genomics, Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, United Kingdom
| | - Andrew J. Page
- Pathogen Genomics, Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, United Kingdom
| | - Åsa Sjöling
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, S-40530, Göteborg, Sweden
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, S-171 77, Stockholm, Sweden
| | - Ann-Mari Svennerholm
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, S-40530, Göteborg, Sweden
| |
Collapse
|
32
|
Chumbler NM, Rutherford SA, Zhang Z, Farrow MA, Lisher JP, Farquhar E, Giedroc DP, Spiller BW, Melnyk RA, Lacy DB. Crystal structure of Clostridium difficile toxin A. Nat Microbiol 2016; 1:15002. [PMID: 27571750 PMCID: PMC4976693 DOI: 10.1038/nmicrobiol.2015.2] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 09/18/2015] [Indexed: 02/04/2023]
Abstract
Clostridium difficile infection is the leading cause of hospital-acquired diarrhoea and pseudomembranous colitis. Disease is mediated by the actions of two toxins, TcdA and TcdB, which cause the diarrhoea, as well as inflammation and necrosis within the colon. The toxins are large (308 and 270 kDa, respectively), homologous (47% amino acid identity) glucosyltransferases that target small GTPases within the host. The multidomain toxins enter cells by receptor-mediated endocytosis and, upon exposure to the low pH of the endosome, insert into and deliver two enzymatic domains across the membrane. Eukaryotic inositol-hexakisphosphate (InsP6) binds an autoprocessing domain to activate a proteolysis event that releases the N-terminal glucosyltransferase domain into the cytosol. Here, we report the crystal structure of a 1,832-amino-acid fragment of TcdA (TcdA1832), which reveals a requirement for zinc in the mechanism of toxin autoprocessing and an extended delivery domain that serves as a scaffold for the hydrophobic α-helices involved in pH-dependent pore formation. A surface loop of the delivery domain whose sequence is strictly conserved among all large clostridial toxins is shown to be functionally important, and is highlighted for future efforts in the development of vaccines and novel therapeutics.
Collapse
Affiliation(s)
- Nicole M. Chumbler
- Chemical and Physical Biology Program, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA
| | - Stacey A. Rutherford
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA
| | - Zhifen Zhang
- Department of Biochemistry, University of Toronto and the Molecular Structure & Function Research Institute at The Hospital for Sick Children, Toronto, Ontario M5S 1A8, Canada
| | - Melissa A. Farrow
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA
| | - John P. Lisher
- Interdisciplinary Graduate Program in Biochemistry, Indiana University, Bloomington, Indiana 47405, USA
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA
| | - Erik Farquhar
- Case Western Reserve University Center for Synchrotron Biosciences, National Synchrotron Light Source, Building 725, Brookhaven National Laboratory, New York 11973, USA
| | - David P. Giedroc
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA
| | - Benjamin W. Spiller
- Chemical and Physical Biology Program, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37212, USA
| | - Roman A. Melnyk
- Department of Biochemistry, University of Toronto and the Molecular Structure & Function Research Institute at The Hospital for Sick Children, Toronto, Ontario M5S 1A8, Canada
| | - D. Borden Lacy
- Chemical and Physical Biology Program, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37205, USA
- The Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee 37212, USA
| |
Collapse
|
33
|
Abstract
High-performance size-exclusion chromatography (HPSEC or SEC) is a method that can be applied to measure size distribution of proteins, including aggregates, monomers, and fragments. In the biopharmaceutical industry the quantitation of aggregates contained in biotherapeutics and protein-based vaccines is critical given the potential impact on safety, immunogenicity, and efficacy. Hence, aggregation analysis of therapeutic proteins or protein-based vaccine products is almost always a requirement of regulatory agencies. SEC, also referred to as gel-filtration chromatography, separates molecules by size through a porous resin stationary phase. Under isocratic flow small molecules are retained on the column longer than large molecules. Here we describe the use of this SEC technique to characterize aggregation levels for four different protein antigens for a Clostridium difficile vaccine.
Collapse
Affiliation(s)
- Catherine Lancaster
- Vaccine Analytical Department, Merck Research Laboratories, Merck & Co., Inc., 770 Sumneytown Pike, P.O. Box 4, WP42A-30, West point, PA, 19486, USA.
| | - Richard R Rustandi
- Vaccine Analytical Department, Merck Research Laboratories, Merck & Co., Inc., 770 Sumneytown Pike, P.O. Box 4, WP42A-30, West point, PA, 19486, USA
| | - Paola Pannizzo
- Merck & Co., Inc., West point, PA, USA
- Johnson & Johnson, Spring House, PA, USA
| | - Sha Ha
- Vaccine Analytical Department, Merck Research Laboratories, Merck & Co., Inc., 770 Sumneytown Pike, P.O. Box 4, WP42A-30, West point, PA, 19486, USA
| |
Collapse
|
34
|
Beltrán AR, Carraro-Lacroix LR, Bezerra CNA, Cornejo M, Norambuena K, Toledo F, Araos J, Pardo F, Leiva A, Sanhueza C, Malnic G, Sobrevia L, Ramírez MA. Escherichia coli Heat-Stable Enterotoxin Mediates Na+/H+ Exchanger 4 Inhibition Involving cAMP in T84 Human Intestinal Epithelial Cells. PLoS One 2015; 10:e0146042. [PMID: 26713849 PMCID: PMC4699896 DOI: 10.1371/journal.pone.0146042] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 12/11/2015] [Indexed: 01/05/2023] Open
Abstract
The enterotoxigenic Escherichia coli strains lead to diarrhoea in humans due to heat-labile and heat-stable (STa) enterotoxins. STa increases Cl-release in intestinal cells, including the human colonic carcinoma T84 cell line, involving increased cGMP and membrane alkalization due to reduced Na+/H+ exchangers (NHEs) activity. Since NHEs modulate intracellular pH (pHi), and NHE1, NHE2, and NHE4 are expressed in T84 cells, we characterized the STa role as modulator of these exchangers. pHi was assayed by the NH4Cl pulse technique and measured by fluorescence microscopy in BCECF-preloaded cells. pHi recovery rate (dpHi/dt) was determined in the absence or presence of 0.25 μmol/L STa (30 minutes), 25 μmol/L HOE-694 (concentration inhibiting NHE1 and NHE2), 500 μmol/L sodium nitroprusside (SNP, spontaneous nitric oxide donor), 100 μmol/L dibutyryl cyclic GMP (db-cGMP), 100 nmol/L H89 (protein kinase A inhibitor), or 10 μmol/L forskolin (adenylyl cyclase activator). cGMP and cAMP were measured in cell extracts by radioimmunoassay, and buffering capacity (ßi) and H+ efflux (JH+) was determined. NHE4 protein abundance was determined by western blotting. STa and HOE-694 caused comparable reduction in dpHi/dt and JH+ (~63%), without altering basal pHi (range 7.144-7.172). STa did not alter ßi value in a range of 1.6 pHi units. The dpHi/dt and JH+ was almost abolished (~94% inhibition) by STa + HOE-694. STa effect was unaltered by db-cGMP or SNP. However, STa and forskolin increased cAMP level. STa-decreased dpHi/dt and JH+ was mimicked by forskolin, and STa + HOE-694 effect was abolished by H89. Thus, incubation of T84 cells with STa results in reduced NHE4 activity leading to a lower capacity of pHi recovery requiring cAMP, but not cGMP. STa effect results in a causal phenomenon (STa/increased cAMP/increased PKA activity/reduced NHE4 activity) ending with intracellular acidification that could have consequences in the gastrointestinal cells function promoting human diarrhoea.
Collapse
Affiliation(s)
- Ana R. Beltrán
- Cellular Physiology Laboratory, Biomedical Department, Faculty of Health Sciences, Universidad de Antofagasta, Antofagasta 1270300, Chile
- Department of Education, Faculty of Education, Universidad de Antofagasta, Antofagasta 1270300, Chile
| | - Luciene R. Carraro-Lacroix
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo 3550308–1009, Brazil
| | - Camila N. A. Bezerra
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo 3550308–1009, Brazil
| | - Marcelo Cornejo
- Cellular Physiology Laboratory, Biomedical Department, Faculty of Health Sciences, Universidad de Antofagasta, Antofagasta 1270300, Chile
| | - Katrina Norambuena
- Cellular Physiology Laboratory, Biomedical Department, Faculty of Health Sciences, Universidad de Antofagasta, Antofagasta 1270300, Chile
| | - Fernando Toledo
- Department of Basic Sciences, Faculty of Sciences, Universidad del Bío-Bío, Chillán 3780000, Chile
| | - Joaquín Araos
- Cellular and Molecular Physiology Laboratory (CMPL), Division of Obstetrics and Gynecology, Faculty of Medicine, School of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile
| | - Fabián Pardo
- Cellular and Molecular Physiology Laboratory (CMPL), Division of Obstetrics and Gynecology, Faculty of Medicine, School of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile
| | - Andrea Leiva
- Cellular and Molecular Physiology Laboratory (CMPL), Division of Obstetrics and Gynecology, Faculty of Medicine, School of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile
| | - Carlos Sanhueza
- Cellular and Molecular Physiology Laboratory (CMPL), Division of Obstetrics and Gynecology, Faculty of Medicine, School of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile
| | - Gerhard Malnic
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo 3550308–1009, Brazil
| | - Luis Sobrevia
- Department of Physiology, Faculty of Pharmacy, Universidad de Sevilla, Seville E-41012, Spain
- University of Queensland Centre for Clinical Research (UQCCR), Faculty of Medicine and Biomedical Sciences, University of Queensland, Herston, QLD 4029, Queensland, Australia
- Cellular and Molecular Physiology Laboratory (CMPL), Division of Obstetrics and Gynecology, Faculty of Medicine, School of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile
- * E-mail: (MAR); (LS)
| | - Marco A. Ramírez
- Cellular Physiology Laboratory, Biomedical Department, Faculty of Health Sciences, Universidad de Antofagasta, Antofagasta 1270300, Chile
- Cellular and Molecular Physiology Laboratory (CMPL), Division of Obstetrics and Gynecology, Faculty of Medicine, School of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile
- * E-mail: (MAR); (LS)
| |
Collapse
|
35
|
Chen S, Sun C, Wang H, Wang J. The Role of Rho GTPases in Toxicity of Clostridium difficile Toxins. Toxins (Basel) 2015; 7:5254-67. [PMID: 26633511 PMCID: PMC4690124 DOI: 10.3390/toxins7124874] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 11/18/2015] [Accepted: 11/18/2015] [Indexed: 12/18/2022] Open
Abstract
Clostridium difficile (C. difficile) is the main cause of antibiotic-associated diarrhea prevailing in hospital settings. In the past decade, the morbidity and mortality of C. difficile infection (CDI) has increased significantly due to the emergence of hypervirulent strains. Toxin A (TcdA) and toxin B (TcdB), the two exotoxins of C. difficile, are the major virulence factors of CDI. The common mode of action of TcdA and TcdB is elicited by specific glucosylation of Rho-GTPase proteins in the host cytosol using UDP-glucose as a co-substrate, resulting in the inactivation of Rho proteins. Rho proteins are the key members in many biological processes and signaling pathways, inactivation of which leads to cytopathic and cytotoxic effects and immune responses of the host cells. It is supposed that Rho GTPases play an important role in the toxicity of C. difficile toxins. This review focuses on recent progresses in the understanding of functional consequences of Rho GTPases glucosylation induced by C. difficile toxins and the role of Rho GTPases in the toxicity of TcdA and TcdB.
Collapse
Affiliation(s)
- Shuyi Chen
- School of Bioscience and Bioengineering, South China University of Technology (SCUT), Guangzhou 510006, China.
| | - Chunli Sun
- School of Bioscience and Bioengineering, South China University of Technology (SCUT), Guangzhou 510006, China.
| | - Haiying Wang
- School of Bioscience and Bioengineering, South China University of Technology (SCUT), Guangzhou 510006, China.
| | - Jufang Wang
- School of Bioscience and Bioengineering, South China University of Technology (SCUT), Guangzhou 510006, China.
| |
Collapse
|
36
|
Hu JC, Greene CJ, King-Lyons ND, Connell TD. The Divergent CD8+ T Cell Adjuvant Properties of LT-IIb and LT-IIc, Two Type II Heat-Labile Enterotoxins, Are Conferred by Their Ganglioside-Binding B Subunits. PLoS One 2015; 10:e0142942. [PMID: 26565800 PMCID: PMC4643920 DOI: 10.1371/journal.pone.0142942] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 10/28/2015] [Indexed: 11/19/2022] Open
Abstract
Poor immune responses elicited by vaccine antigens can be enhanced by the use of appropriate adjuvants. Type II heat-labile enterotoxins (HLT) produced by Escherichia coli are extremely potent adjuvants that augment both humoral and cellular immunity to co-administered antigens. Recent findings demonstrate that LT-IIb and LT-IIc, two type II HLT adjuvants, exhibit potent, yet distinguishable CD8+ T cell adjuvant properties. While LT-IIc elicits a robust and rapid response at one week after administration, LT-IIb engenders a more gradual and slower expansion of antigen-specific CD8+ T cells that correlates with improved immunity. The variations in immune effects elicited by the HLT adjuvants have been generally attributed to their highly divergent B subunits that mediate binding to various gangliosides on cell surfaces. Yet, HLT adjuvants with point mutations in the B subunit that significantly alter ganglioside binding retain similar adjuvant functions. Therefore, the contribution of the B subunits to adjuvanticity remains unclear. To investigate the influence of the B subunits on the enhancement of immune responses by LT-IIb and LT-IIc, chimeric HLT were engineered in which the B subunits of the two adjuvants were exchanged. Comparing the immune potentiating characteristics of both native and chimeric HLT adjuvants, it was found that not all the adjuvant characteristics of the HLT adjuvants were modulated by the respective B subunits. Specifically, the differences in the CD8+ T cell kinetics and protective responses elicited by LT-IIb and LT-IIc did indeed followed their respective B subunits. However, induction of IL-1 from macrophages and the capacity to intoxicate cells in a mouse Y1 adrenal cell bioassay did not correlate with the B subunits. Therefore, it is likely that additional factors other than the B subunits contribute to the effects elicited by the HLT adjuvants.
Collapse
Affiliation(s)
- John C. Hu
- Department of Microbiology & Immunology, The Witebsky Center for Microbial Pathogenesis and Immunology, The University at Buffalo, Buffalo, New York, United States of America
| | - Christopher J. Greene
- Department of Microbiology & Immunology, The Witebsky Center for Microbial Pathogenesis and Immunology, The University at Buffalo, Buffalo, New York, United States of America
| | - Natalie D. King-Lyons
- Department of Microbiology & Immunology, The Witebsky Center for Microbial Pathogenesis and Immunology, The University at Buffalo, Buffalo, New York, United States of America
| | - Terry D. Connell
- Department of Microbiology & Immunology, The Witebsky Center for Microbial Pathogenesis and Immunology, The University at Buffalo, Buffalo, New York, United States of America
- * E-mail:
| |
Collapse
|
37
|
Mordkovich NN, Okorokova NA, Veiko VP. [Structural and Functional Organization of the Signal Peptide of ProEnterotoxin B from Staphylococcus aureus]. Prikl Biokhim Mikrobiol 2015; 51:561-569. [PMID: 26859957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A series of genes of proenterotoxin B from Staphylococcus aureus containing signal peptide mutant forms was constructed in order to study the functional roles of the introduced mutations. It was shown that a continuous mutation in the n-region of the signal peptide does not affect the secretion efficiency of proenterotoxin B, in contrast to the analogous mutation in the h-region. Point mutations of the proprotein signal peptide, including the N-terminal amino-acid residue of the mature protein, were obtained. It was shown that the introduced structural. changes cause a decrease in secretion efficiency and a redistribution of the protein in various compartments of Escherichia coli cells.
Collapse
|
38
|
Yu H, Chen K, Wu J, Yang Z, Shi L, Barlow LL, Aronoff DM, Garey KW, Savidge TC, von Rosenvinge EC, Kelly CP, Feng H. Identification of toxemia in patients with Clostridium difficile infection. PLoS One 2015; 10:e0124235. [PMID: 25885671 PMCID: PMC4401762 DOI: 10.1371/journal.pone.0124235] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 02/27/2015] [Indexed: 01/05/2023] Open
Abstract
Toxemia can develop in Clostridium difficile-infected animals, and correlates with severe and fulminant disease outcomes. Circumstantial evidence suggests that toxemia may occur in patients with C. difficile infection (CDI), but positive diagnosis is extremely rare. We analyzed the potential for C. difficile toxemia in patients, determined its characteristics, and assessed challenges. C. difficile toxins in serum from patients were tested using an ultrasensitive cell-based assay and further confirmed by Rac1 glucosylation assay. The factors that hinder a diagnosis of toxemia were assessed, including investigation of toxin stability, the level of toxins-specific neutralizing antibodies in sera and its effect on diagnosis limits. CDI patients develop detectable toxemia in some cases (2.3%). Toxins were relatively stable in stored sera. Neutralizing anti-toxin antibodies were present during infection and positively correlated with the diagnosis limits. Thus, the masking effect of toxin-specific neutralizing antibodies is the major obstacle in diagnosing C. difficile toxemia using cell-based bioassays.
Collapse
Affiliation(s)
- Hua Yu
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland, United States of America
| | - Kevin Chen
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland, United States of America
| | - Jianguo Wu
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland, United States of America
| | - Zhiyong Yang
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland, United States of America
| | - Lianfa Shi
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland, United States of America
| | - Lydia L. Barlow
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - David M. Aronoff
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America; Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Kevin W. Garey
- University of Houston College of Pharmacy, Houston, Texas, United States of America; Baylor St. Luke's Medical Center, Houston, Texas, United States of America; University of Texas School of Public Health, Houston, Texas, United States of America
| | - Tor C. Savidge
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas, United States of America; Texas Children's Microbiome Center, Texas Children's Hospital, Houston, Texas, United States of America
| | - Erik C. von Rosenvinge
- Division of Gastroenterology & Hepatology, Department of Medicine, University of Maryland, Baltimore, Maryland, United States of America; VA Maryland Health Care System, Baltimore, Maryland, United States of America
| | - Ciaran P. Kelly
- Department of Medicine, Harvard Medical School and Celiac Center, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States of America; Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Hanping Feng
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland, United States of America
- * E-mail:
| |
Collapse
|
39
|
Bennett MA, Shern JF, Kahn RA. Reverse two-hybrid techniques in the yeast Saccharomyces cerevisiae. Methods Mol Biol 2015; 1278:433-446. [PMID: 25859967 DOI: 10.1007/978-1-4939-2425-7_28] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Use of the yeast two-hybrid system has provided definition to many previously uncharacterized pathways through the identification and characterization of novel protein-protein interactions. The two-hybrid system uses the bifunctional nature of transcription factors, such as the yeast enhancer Gal4, to allow protein-protein interactions to be monitored through changes in transcription of reporter genes. Once a positive interaction has been identified, either of the interacting proteins can be mutated by site-specific or randomly introduced changes, to produce proteins with a decreased ability to interact. Mutants generated using this strategy are very powerful reagents in tests of the biological significance of the interaction and in defining the residues involved in the interaction. Such techniques are termed reverse two-hybrid methods. We describe a reverse two-hybrid method that generates loss-of-interaction mutations of the catalytic subunit of the Escherichia coli heat-labile toxin (LTA1) with decreased binding to the active (GTP-bound) form of human ARF3, its protein cofactor. While newer methods are emerging for performing interaction screens in mammalian cells, instead of yeast, the use of reverse two-hybrid in yeast remains a robust and powerful means of identifying loss-of-interaction point mutants and compensating changes that remain among the most powerful tools of testing the biological significance of a protein-protein interaction.
Collapse
Affiliation(s)
- Matthew A Bennett
- Department of Biochemistry, Emory University School of Medicine, 1510 Clifton Rd., Atlanta, GA, 30322-3050, USA
| | | | | |
Collapse
|
40
|
Komiażyk M, Palczewska M, Pikula S, Groves P. Bacterial type AB₅ enterotoxins--structure, function and mechanism of action. Postepy Biochem 2015; 61:430-435. [PMID: 27048097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
One of the main factors causing bacterial diarrhea are AB₅ enterotoxins. This group is divided into four families: pertussis toxin, cholera toxin, shiga toxin and subtilase cytotoxin. In this review we will describe the activity, structure and function of the cholera and shiga toxin families. The AB₅ enterotoxins contain a catalytic subunit A and pentameric subunit B, which binds to the cell surface within lipid rafts. The cholera toxin family cause the constitutive activation of Gsa protein, which results in cAMP production, an opening of the chloride channels and releases chloride ions into the lumen of the small intestine. In contrast, the shiga toxin family has a cytotoxic effect on epithelial cells. It can inhibit protein synthesis leading to cell death. Although AB₅ has a toxic activity, the B₅ subunits have a significant potential as a transporter for proteins with anticancer activity and as a tool for the visualization of lipid rafts and cancer cells.
Collapse
|
41
|
Yelland TS, Naylor CE, Bagoban T, Savva CG, Moss DS, McClane BA, Blasig IE, Popoff M, Basak AK. Structure of a C. perfringens enterotoxin mutant in complex with a modified Claudin-2 extracellular loop 2. J Mol Biol 2014; 426:3134-3147. [PMID: 25020226 PMCID: PMC10921947 DOI: 10.1016/j.jmb.2014.07.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 06/25/2014] [Accepted: 07/07/2014] [Indexed: 12/01/2022]
Abstract
CPE (Clostridium perfringens enterotoxin) is the major virulence determinant for C. perfringens type-A food poisoning, the second most common bacterial food-borne illness in the UK and USA. After binding to its receptors, which include particular human claudins, the toxin forms pores in the cell membrane. The mature pore apparently contains a hexamer of CPE, claudin and, possibly, occludin. The combination of high binding specificity with cytotoxicity has resulted in CPE being investigated, with some success, as a targeted cytotoxic agent for oncotherapy. In this paper, we present the X-ray crystallographic structure of CPE in complex with a peptide derived from extracellular loop 2 of a modified, CPE-binding Claudin-2, together with high-resolution native and pore-formation mutant structures. Our structure provides the first atomic-resolution data on any part of a claudin molecule and reveals that claudin's CPE-binding fingerprint (NPLVP) is in a tight turn conformation and binds, as expected, in CPE's C-terminal claudin-binding groove. The leucine and valine residues insert into the binding groove while the first residue, asparagine, tethers the peptide via an interaction with CPE's aspartate 225 and the two prolines are required to maintain the tight turn conformation. Understanding the structural basis of the contribution these residues make to binding will aid in engineering CPE to target tumor cells.
Collapse
Affiliation(s)
- Tamas S Yelland
- Department of Biological Sciences, Birkbeck College, London WC1E 7HX, UK
| | - Claire E Naylor
- Department of Biological Sciences, Birkbeck College, London WC1E 7HX, UK
| | - Tannya Bagoban
- Department of Biological Sciences, Birkbeck College, London WC1E 7HX, UK
| | - Christos G Savva
- Department of Biological Sciences, Birkbeck College, London WC1E 7HX, UK
| | - David S Moss
- Department of Biological Sciences, Birkbeck College, London WC1E 7HX, UK
| | - Bruce A McClane
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Ingolf E Blasig
- Leibniz-Institut für Molekulare Pharmakologie im Forshungsverbund Berlin e.V. (FMP), 13125 Berlin, Germany
| | - M Popoff
- Anaerobic Bacteria and Toxins Unit, Department of Microbiology, Institut Pasteur, 75724 Paris Cedex 15, France
| | - Ajit K Basak
- Department of Biological Sciences, Birkbeck College, London WC1E 7HX, UK.
| |
Collapse
|
42
|
Jochim N, Gerhard R, Just I, Pich A. Time-resolved cellular effects induced by TcdA from Clostridium difficile. Rapid Commun Mass Spectrom 2014; 28:1089-1100. [PMID: 24711272 DOI: 10.1002/rcm.6882] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 02/07/2014] [Accepted: 02/26/2014] [Indexed: 06/03/2023]
Abstract
RATIONALE The anaerobe Clostridium difficile is a common pathogen that causes infection of the colon leading to diarrhea or pseudomembranous colitis. Its major virulence factors are toxin A (TcdA) and toxin B (TcdB), which specifically inactivate small GTPases by glucosylation leading to reorganization of the cytoskeleton and finally to cell death. In the present work a quantitative proteome analysis using the isotope-coded protein label (ICPL) approach was conducted to investigate proteome changes in the colon cell line Caco-2 after treatment with recombinant wild-type TcdA (rTcdA-wt) or a glucosyltransferase-deficient mutant TcdA (rTcdA-mut). METHODS Proteins from crude cell lysates or cellular subfractions were identified by liquid chromatography/electrospray ionization mass spectrometry (LC/ESI-MS). Two time points (5 h, 24 h) of toxin treatment were analyzed and about 4000 proteins were identified in each case. RESULTS After 5 h treatment with rTcdA-wt, 150 proteins had a significantly altered abundance; rTcdA-mut caused regulation of 50 proteins at this time point. After 24 h treatment with rTcdA-wt changes in abundance of 61 proteins were observed, but no changes in protein abundance were detected after 24 h if cells were treated with rTcdA-mut. TcdA affected several proteins involved in signaling events, cytoskeleton and cell-cell contact organization, translation, and metabolic processes. The ICPL-dependent quantification was verified by label-free targeted MS techniques based on multiple reaction monitoring (MRM) and triple quadrupole mass spectrometry. CONCLUSIONS LC/MS-based proteome analyses and the ICPL approach revealed comprehensive and reproducible proteome date and provided new insights into the cellular effects of clostridial glucosylating toxins (CGT).
Collapse
Affiliation(s)
- Nelli Jochim
- Hannover Medical School, Institute of Toxicology, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| | | | | | | |
Collapse
|
43
|
Sachdeva A, Singh AK, Sharma SK. An electrochemiluminescence assay for the detection of bio threat agents in selected food matrices and in the screening of Clostridium botulinum outbreak strains associated with type A botulism. J Sci Food Agric 2014; 94:707-712. [PMID: 23873138 DOI: 10.1002/jsfa.6310] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 05/02/2013] [Accepted: 07/19/2013] [Indexed: 06/02/2023]
Abstract
BACKGROUND Specific screening methods for complex food matrices are needed that enable unambiguous and sensitive detection of bio threat agents (BTAs) such as Bacillus anthracis spores and microbial toxins (e.g. staphylococcal enterotoxin B (SEB) and clostridial botulinum neurotoxins (BoNTs)). The present study describes an image-based 96-well Meso Scale Discovery (MSD) electrochemiluminescence (ECL) assay for simultaneous detection of BTAs in dairy milk products. RESULTS The limit of detection of this ECL assay is 40 pg mL⁻¹ for BoNT/A complex, 10 pg mL⁻¹ for SEB and 40000 CFU mL⁻¹ for Bacillus anthracis spores in dairy milk products. The ECL assay was successfully applied to screen type A Clostridium botulinum outbreak strains. CONCLUSION The results of the study indicate that this ECL assay is very sensitive, rapid (<6 h) and multiplex in nature. The ECL assay has potential for use as an in vitro screening method for BTAs over other comparable immunoassays.
Collapse
Affiliation(s)
- Amita Sachdeva
- Division of Microbiology, Office of Regulatory Science, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, 5100 Paint Branch Parkway, College Park, MD, 20740, USA
| | | | | |
Collapse
|
44
|
Fernandes da Costa SP, Savva CG, Bokori-Brown M, Naylor CE, Moss DS, Basak AK, Titball RW. Identification of a key residue for oligomerisation and pore-formation of Clostridium perfringens NetB. Toxins (Basel) 2014; 6:1049-61. [PMID: 24625763 PMCID: PMC3968376 DOI: 10.3390/toxins6031049] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 02/26/2014] [Accepted: 03/03/2014] [Indexed: 11/22/2022] Open
Abstract
Necrotic enteritis toxin B (NetB) is a β-pore-forming toxin produced by Clostridium perfringens and has been identified as a key virulence factor in the pathogenesis of avian necrotic enteritis, a disease causing significant economic damage to the poultry industry worldwide. In this study, site-directed mutagenesis was used to identify amino acids that play a role in NetB oligomerisation and pore-formation. NetB K41H showed significantly reduced toxicity towards LMH cells and human red blood cells relative to wild type toxin. NetB K41H was unable to oligomerise and form pores in liposomes. These findings suggest that NetB K41H could be developed as a genetic toxoid vaccine to protect against necrotic enteritis.
Collapse
Affiliation(s)
| | - Christos G Savva
- Department of Biological Sciences, School of Crystallography, Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London WC1E 7HX, UK.
| | - Monika Bokori-Brown
- College of Life and Environmental Sciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK.
| | - Claire E Naylor
- Department of Biological Sciences, School of Crystallography, Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London WC1E 7HX, UK.
| | - David S Moss
- Department of Biological Sciences, School of Crystallography, Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London WC1E 7HX, UK.
| | - Ajit K Basak
- Department of Biological Sciences, School of Crystallography, Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London WC1E 7HX, UK.
| | - Richard W Titball
- College of Life and Environmental Sciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK.
| |
Collapse
|
45
|
Zhao Z, Li B, Sun HQ, Zhang JY, Wang YL, Chen L, Hu J, He YF, Zeng H, Zou QM, Wu C. Fine-mapping of immunodominant linear B-cell epitopes of the Staphylococcus aureus SEB antigen using short overlapping peptides. PLoS One 2014; 9:e90445. [PMID: 24599257 PMCID: PMC3943954 DOI: 10.1371/journal.pone.0090445] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2013] [Accepted: 01/31/2014] [Indexed: 01/06/2023] Open
Abstract
Staphylococcal enterotoxin B (SEB) is one of the most potent Staphylococcus aureus exotoxins (SEs). Due to its conserved sequence and stable structure, SEB might be a good candidate antigen for MRSA vaccines. Although cellular immune responses to SEB are well-characterized, much less is known regarding SEB-specific humoral immune responses, particularly regarding detailed epitope mapping. In this study, we utilized a recombinant nontoxic mutant of SEB (rSEB) and an AlPO4 adjuvant to immunize BALB/c mice and confirmed that rSEB can induce a high antibody level and effective immune protection against MRSA infection. Next, the antisera of immunized mice were collected, and linear B cell epitopes within SEB were finely mapped using a series of overlapping synthetic peptides. Three immunodominant B cell epitopes of SEB were screened by ELISA, including a novel epitope, SEB205-222, and two known epitopes, SEB97–114 and SEB247-261. Using truncated peptides, an ELISA was performed with peptide-KLH antisera, and the core sequence of the three immunodominant B cell epitopes were verified as SEB97-112, SEB207-222, and SEB247-257. In vitro, all of the immunodominant epitope-specific antisera (anti-SEB97-112, anti-SEB207-222 and anti-SEB247-257) were observed to inhibit SEB-induced T cell mitogenesis and cytokine production from splenic lymphocytes of BALB/c mice. The homology analysis indicated that SEB97–112 and SEB207-222 were well-conserved among different Staphylococcus aureus strains. The 3D crystal structure of SEB indicated that SEB97–112 was in the loop region inside SEB, whereas SEB207-222 and SEB247-257 were in the β-slice region outside SEB. In summary, the fine-mapping of linear B-cell epitopes of the SEB antigen in this study will be useful to understand anti-SEB immunity against MRSA infection further and will be helpful to optimize MRSA vaccine designs that are based on the SEB antigen.
Collapse
Affiliation(s)
- Zhuo Zhao
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
| | - Bin Li
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
| | - He-Qiang Sun
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
| | - Jin-Yong Zhang
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
| | - Yi-Lin Wang
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
| | - Li Chen
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
| | - Jian Hu
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, PR China
| | - Ya-Fei He
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, PR China
| | - Hao Zeng
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
| | - Quan-Ming Zou
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
- * E-mail: (CW); (Q-MZ)
| | - Chao Wu
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
- * E-mail: (CW); (Q-MZ)
| |
Collapse
|
46
|
Liubavina IA, Brovko FA, Valiakina TI, Vertiev IV, Grishin EV. [Development of methods for rapid test of staphylococcal enterotoxin A in food]. Bioorg Khim 2014; 40:186-195. [PMID: 25895338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Noninstrumental methods of qualitative rapid test for detection of staphylococcal enterotoxin A (SEA) in milk foods sample and brothof using immunochromatography (IC) and dot-assay has been developed. Monoclonal antibodies to SEA with colloidal gold forimmunochromatography; monoclonal antibodies to SEA with colloidal gold or biotinylated monoclonal antibodies and streptavidin-peroxidase conjugate for dot-assay were used to visualize the results. The detection limits, ng/mL: 10 (IC), 20 (dot-assay with antibody-colloidal gold), 10 (dot-assay with STR-HRP), 4 (ELISA). Time of assay, min: 25 (IC), 60 (dot-assay with antibody-colloidal gold), 70 (dot-assay with STR-HRPO, 150 (ELISA).
Collapse
|
47
|
Chang HC, Chen JC, Yang JL, Tsay HS, Hsiang CY, Ho TY. The suppressive activities of six sources of medicinal ferns known as gusuibu on heat-labile enterotoxin-induced diarrhea. Molecules 2014; 19:2114-20. [PMID: 24552982 PMCID: PMC6271568 DOI: 10.3390/molecules19022114] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 01/24/2014] [Accepted: 02/07/2014] [Indexed: 11/16/2022] Open
Abstract
Diarrheal disease is one of the most important worldwide health problems. Enterotoxigenic Escherichia coli (ETEC) is the most frequently isolated enteropathogen in diarrheal diseases. In developing countries, a very large number of people, especially children, suffer from diarrhea. To combat this problem, World Health Organization has constituted the Diarrhea Diseases Control Program which guides studies on traditional medicinal practices and preventive measures. Gusuibu, a traditional folk medicine, has been claimed to heal certain types of diarrhea. However, so far no scientific study has been carried out on the anti-diarrheal mechanism of Gusiubu. The present study was performed to examine the suppressive activities of ethanol extracts of six sources of folk medicinal ferns used as Gusuibu on heat-labile enterotoxin (LT)-induced diarrhea. Inhibitory effects of six sources were evaluated on the ETEC LT subunit B (LTB) and monosialotetrahexosylganglioside (GMI) interaction by GM1-enzyme linked immunosorbent assay and patent mouse gut assay. Our results indicated that Drynaria fortunei had no anti-diarrheal effect, while, among the remaining five folk medicinal ferns, four belonging to family Davalliaceae had significant abilities on both the blocking of LTB and GM1 interaction and the inhibition of LT-induced diarrhea. In conclusion, these findings suggested the potential application of Gusuibu as an anti-diarrheal remedy.
Collapse
Affiliation(s)
- Hung-Chi Chang
- Department of Golden-Ager Industry Management, Chaoyang University of Technology, Taichung 41349, Taiwan
| | - Jaw-Chyun Chen
- Department of Medicinal Botany and Health Applications, Da-Yeh University, Changhua 51591, Taiwan
| | - Jiun-Long Yang
- Department of Biological Science and Technology, China Medical University, Taichung 40402, Taiwan
| | - Hsin-Sheng Tsay
- Graduate Institute of Biochemical Sciences and Technology, Chaoyang University of Technology, Taichung 41349, Taiwan
| | - Chien-Yun Hsiang
- Department of Microbiology, China Medical University, Taichung 40402, Taiwan
| | - Tin-Yun Ho
- Graduate Institute of Chinese Medicine, China Medical University, Taichung 40402, Taiwan.
| |
Collapse
|
48
|
Pera A, Campos C, Corona A, Sanchez-Correa B, Tarazona R, Larbi A, Solana R. CMV latent infection improves CD8+ T response to SEB due to expansion of polyfunctional CD57+ cells in young individuals. PLoS One 2014; 9:e88538. [PMID: 24533103 PMCID: PMC3922920 DOI: 10.1371/journal.pone.0088538] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 01/07/2014] [Indexed: 01/19/2023] Open
Abstract
Cytomegalovirus (CMV) latent infection has a deleterious effect on the efficacy of influenza vaccination in the elderly, suggesting that CMV restricts immunological diversity impairing the immune system functionality in old age. Polyfunctional T cells produce multiple cytokines and higher amounts than mono-functional T cells. High number of polyfunctional T cells correlates with better prognosis during infection. Thus, the efficiency of T cell response associates with quality (polyfunctionality) rather than with quantity (percentage of T cells). We analyze the effect of CMV infection on CD8+ T cells polyfunctionality ―degranulation (CD107a), IFN-gamma and TNF-alpha production―, from young CMV-seropositive and CMV-seronegative individuals and in middle age CMV-seropositive donors, in response to Staphylococcal Enterotoxin B (SEB). Our results show a higher percentage of polyfunctional CD8+ T cells in young CMV-seropositive individuals compared to CMV-seronegative. Also, we find an expansion of CD8+CD57+ T cells in CMV-seropositive individuals, which are more polyfunctional than CD8+CD57− cells. In middle age individuals there is a higher frequency of SEB-responding CD8+ T cells, mainly TNF-alpha or TNF-alpha/IFN-gamma producers, whereas the percentage of polyfunctional cells (IFN-gamma/TNF-alpha/CD107a) is similar to the percentages found in young CMV-seropositive. Therefore, whereas it has been shown that CMV latent infection can be detrimental for immune response in old individuals, our results indicate that CMV-seropositivity is associated to higher levels of polyfunctional CD8+ T cells in young and middle age donors. This increase in polyfunctionality, which can provide an immunological advantage in the response to other pathogens, is due to a CD8+CD57+ T cell expansion in CMV-seropositive individuals and it is independent of age. Conversely, age could contribute to the inflammation found in old individuals by increasing the percentage of cells producing pro-inflammatory cytokines. These findings highlight the necessity of further studies on the benefits/detrimental effects of CMV infection in the response to vaccination and other infections.
Collapse
Affiliation(s)
- Alejandra Pera
- Department of Immunology, Maimonides Institute for Biomedical Research (IMIBIC) – Reina Sofía University Hospital – University of Cordoba, Cordoba, Spain
- * E-mail: .
| | - Carmen Campos
- Department of Immunology, Maimonides Institute for Biomedical Research (IMIBIC) – Reina Sofía University Hospital – University of Cordoba, Cordoba, Spain
| | - Alonso Corona
- Department of Immunology, Maimonides Institute for Biomedical Research (IMIBIC) – Reina Sofía University Hospital – University of Cordoba, Cordoba, Spain
| | | | - Raquel Tarazona
- Immunology Unit, Department of Physiology, University of Extremadura, Cáceres, Spain
| | - Anis Larbi
- Singapore Immunology Network (SIgN), Biopolis, Agency for Science, Technology and Research, Singapore, Singapore
| | - Rafael Solana
- Department of Immunology, Maimonides Institute for Biomedical Research (IMIBIC) – Reina Sofía University Hospital – University of Cordoba, Cordoba, Spain
| |
Collapse
|
49
|
Zaraket H, Otsuka T, Saito K, Dohmae S, Takano T, Higuchi W, Ohkubo T, Ozaki K, Takano M, Reva I, Baranovich T, Yamamoto T. Molecular Characterization of Methicillin-ResistantStaphylococcus aureusin Hospitals in Niigata, Japan: Divergence and Transmission. Microbiol Immunol 2013; 51:171-6. [PMID: 17310084 DOI: 10.1111/j.1348-0421.2007.tb03898.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The major methicillin-resistant Staphylococcus aureus(MRSA) distributed among hospitals in Japan is New York/Japan clone [multilocus sequence type 5 (ST5), agr type 2 and methicillin resistance locus type (SCC mec) II] which possesses both the toxic shock syndrome toxin 1 gene (tst) and staphylococcal enterotoxin C gene (sec). In this study, we collected 245 MRSA strains from four hospitals during 2001 to 2005 in Niigata, Japan, and analyzed tst and sec genes and SCC mec type among them. A total of 13 strains were further examined for their genotypes, virulence gene patterns and drug resistance. Among the 245 strains four tst sec genes patterns were observed; tst(+) sec(+) strains represented a majority of 86.5% and 9.4% were tst(-) sec(-). SCCmec typing revealed that 91.4% had type II, 4.1% type IV and 4.1% type I. Multilocus sequence typing (MLST) revealed that 10 of the 13 typed strains belonged to clonal complex 5 (7 had ST5 while 3 were single locus variants of ST5) with similar characteristics to the New York/Japan clone and possessed multi-drug resistance with high virulence gene content. The remaining 3 strains were ST8 (n=2) and ST91 (n=1). The ST91 strain had SCC mec IV and seemed to originate in the community, while ST8 strains exhibited SCC mec type I, which is distinct from community type IV. The data suggest that MRSA in hospitals in Niigata now mainly includes the New York/Japan clone (undergoing genomic divergence and clonal expansion) and other minor types (e.g. ST8) as well as the community type.
Collapse
Affiliation(s)
- Hassan Zaraket
- Division of Bacteriology, Department of Infectious Disease Control and International Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Nazarian S, Gargari SLM, Rasooli I, Hasannia S, Pirooznia N. A PLGA-encapsulated chimeric protein protects against adherence and toxicity of enterotoxigenic Escherichia coli. Microbiol Res 2013; 169:205-12. [PMID: 23906742 DOI: 10.1016/j.micres.2013.06.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 05/20/2013] [Accepted: 06/14/2013] [Indexed: 01/14/2023]
Abstract
Enterotoxigenic Escherichia coli (ETEC) are the most common cause of diarrhea among children. Colonization factors and enterotoxins are the major ETEC candidate vaccines. Since protection against ETEC mostly occurs by induction of IgA antibodies, much effort is focused on the development of oral vaccines. In this study oral immunogenicity of a poly(lactic-co-glycolic acid) (PLGA) encapsulated chimeric protein containing CfaB, CstH, CotA and LTB (Heat-labile B subunit) was investigated. The protein was encapsulated in PLGA by double emulsion method and nanoparticles were characterized physicochemically. Immunogenicity was assessed by evaluating IgG1, IgG2 and IgA titers after BALB/c mice vaccination. Non aggregated nanoparticles had a spherical shape with an average particle size of 252.7±23 nm and 91.96±4.4% of encapsulation efficiency. Western blotting showed maintenance of the molecular weight and antigenicity of the released protein. Oral immunization of mice induced serum IgG and fecal IgA antibody responses. Immunization induced protection against ETEC binding to Caco-2 cells. The effect of LT toxin on fluid accumulation in ileal loops was neutralized by inhibition of enterotoxin binding to GM1-ganglosides. Delivery of the chimeric protein in PLGA elicited both systemic and mucosal immune responses. The findings could be exploited to development of oral multi-component ETEC prophylactic measures.
Collapse
Affiliation(s)
| | | | - Iraj Rasooli
- Department of Biology, Shahed University, Tehran, Iran
| | - Sadegh Hasannia
- Tarbiat Modares University, Faculty of Biological Sciences, Tehran, Iran
| | - Nazanin Pirooznia
- Faculty of Science, Department of Biology, University of Guilan, Rasht, Iran
| |
Collapse
|