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Yu C, Richly M, Hoang TT, El Beheiry M, Türkcan S, Masson JB, Alexandrou A, Bouzigues CI. Confinement energy landscape classification reveals membrane receptor nano-organization mechanisms. Biophys J 2024; 123:1882-1895. [PMID: 38845200 PMCID: PMC11267427 DOI: 10.1016/j.bpj.2024.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 03/01/2024] [Accepted: 06/03/2024] [Indexed: 06/22/2024] Open
Abstract
The cell membrane organization has an essential functional role through the control of membrane receptor confinement in micro- or nanodomains. Several mechanisms have been proposed to account for these properties, although some features have remained controversial, notably the nature, size, and stability of cholesterol- and sphingolipid-rich domains or lipid rafts. Here, we probed the effective energy landscape acting on single-nanoparticle-labeled membrane receptors confined in raft nanodomains- epidermal growth factor receptor (EGFR), Clostridium perfringens ε-toxin receptor (CPεTR), and Clostridium septicum α-toxin receptor (CSαTR)-and compared it with hop-diffusing transferrin receptors. By establishing a new analysis pipeline combining Bayesian inference, decision trees, and clustering approaches, we systematically classified single-protein trajectories according to the type of effective confining energy landscape. This revealed the existence of only two distinct organization modalities: confinement in a quadratic energy landscape for EGFR, CPεTR, and CSαTR (A), and free diffusion in confinement domains resulting from the steric hindrance due to F-actin barriers for transferrin receptor (B). The further characterization of effective confinement energy landscapes by Bayesian inference revealed the role of interactions with the domain environment in cholesterol- and sphingolipid-rich domains with (EGFR) or without (CPεTR and CSαTR) interactions with F-actin to regulate the confinement energy depth. These two distinct mechanisms result in the same organization type (A). We revealed that the apparent domain sizes for these receptor trajectories resulted from Brownian exploration of the energy landscape in a steady-state-like regime at a common effective temperature, independently of the underlying molecular mechanisms. These results highlight that confinement domains may be adequately described as interaction hotspots rather than rafts with abrupt domain boundaries. Altogether, these results support a new model for functional receptor confinement in membrane nanodomains and pave the way to the constitution of an atlas of membrane protein organization.
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Affiliation(s)
- Chao Yu
- Laboratoire Optique et Biosciences, CNRS UMR74645, Inserm U1182, Ecole Polytechnique, Institut Polytechnique Paris, Palaiseau, France
| | - Maximilian Richly
- Laboratoire Optique et Biosciences, CNRS UMR74645, Inserm U1182, Ecole Polytechnique, Institut Polytechnique Paris, Palaiseau, France
| | - Thi Thuy Hoang
- Laboratoire Optique et Biosciences, CNRS UMR74645, Inserm U1182, Ecole Polytechnique, Institut Polytechnique Paris, Palaiseau, France
| | - Mohammed El Beheiry
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Decision and Bayesian Computation, Paris, France; Épiméthée, INRIA, Paris, France
| | - Silvan Türkcan
- Laboratoire Optique et Biosciences, CNRS UMR74645, Inserm U1182, Ecole Polytechnique, Institut Polytechnique Paris, Palaiseau, France
| | - Jean-Baptiste Masson
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Decision and Bayesian Computation, Paris, France; Épiméthée, INRIA, Paris, France
| | - Antigoni Alexandrou
- Laboratoire Optique et Biosciences, CNRS UMR74645, Inserm U1182, Ecole Polytechnique, Institut Polytechnique Paris, Palaiseau, France
| | - Cedric I Bouzigues
- Laboratoire Optique et Biosciences, CNRS UMR74645, Inserm U1182, Ecole Polytechnique, Institut Polytechnique Paris, Palaiseau, France.
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Ribeiro TP, Martins-de-Sa D, Macedo LLP, Lourenço-Tessutti IT, Ruffo GC, Sousa JPA, Rósario Santana JMD, Oliveira-Neto OB, Moura SM, Silva MCM, Morgante CV, Oliveira NG, Basso MF, Grossi-de-Sa MF. Cotton plants overexpressing the Bacillus thuringiensis Cry23Aa and Cry37Aa binary-like toxins exhibit high resistance to the cotton boll weevil (Anthonomus grandis). PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 344:112079. [PMID: 38588981 DOI: 10.1016/j.plantsci.2024.112079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 03/27/2024] [Accepted: 03/28/2024] [Indexed: 04/10/2024]
Abstract
The cotton boll weevil (CBW, Anthonomus grandis) stands as one of the most significant threats to cotton crops (Gossypium hirsutum). Despite substantial efforts, the development of a commercially viable transgenic cotton event for effective open-field control of CBW has remained elusive. This study describes a detailed characterization of the insecticidal toxins Cry23Aa and Cry37Aa against CBW. Our findings reveal that CBW larvae fed on artificial diets supplemented exclusively with Cry23Aa decreased larval survival by roughly by 69%, while supplementation with Cry37Aa alone displayed no statistical difference compared to the control. However, the combined provision of both toxins in the artificial diet led to mortality rates approaching 100% among CBW larvae (LC50 equal to 0.26 PPM). Additionally, we engineered transgenic cotton plants by introducing cry23Aa and cry37Aa genes under control of the flower bud-specific pGhFS4 and pGhFS1 promoters, respectively. Seven transgenic cotton events expressing high levels of Cry23Aa and Cry37Aa toxins in flower buds were selected for greenhouse bioassays, and the mortality rate of CBW larvae feeding on their T0 and T1 generations ranged from 75% to 100%. Our in silico analyses unveiled that Cry23Aa displays all the hallmark characteristics of β-pore-forming toxins (β-PFTs) that bind to sugar moieties in glycoproteins. Intriguingly, we also discovered a distinctive zinc-binding site within Cry23Aa, which appears to be involved in protein-protein interactions. Finally, we discuss the major structural features of Cry23Aa that likely play a role in the toxin's mechanism of action. In view of the low LC50 for CBW larvae and the significant accumulation of these toxins in the flower buds of both T0 and T1 plants, we anticipate that through successive generations of these transgenic lines, cotton plants engineered to overexpress cry23Aa and cry37Aa hold promise for effectively managing CBW infestations in cotton crops.
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Affiliation(s)
- Thuanne Pires Ribeiro
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil
| | - Diogo Martins-de-Sa
- Department of Cellular Biology, University of Brasília, Brasília, DF 70910-900, Brazil; Genesilico Biotech, Brasília, DF 71503-508, Brazil
| | - Leonardo Lima Pepino Macedo
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil
| | - Isabela Tristan Lourenço-Tessutti
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil
| | - Gustavo Caseca Ruffo
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil; Graduate Program in Genomic Science and Biotechnology, Catholic University of Brasília, Brasília, DF 71966-700, Brazil
| | - João Pedro Abreu Sousa
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil; Graduate Program in Genomic Science and Biotechnology, Catholic University of Brasília, Brasília, DF 71966-700, Brazil
| | - Julia Moura do Rósario Santana
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil; Graduate Program in Genomic Science and Biotechnology, Catholic University of Brasília, Brasília, DF 71966-700, Brazil
| | - Osmundo Brilhante Oliveira-Neto
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil; Euroamerican University Center, Unieuro, Brasília, DF 70790-160, Brazil
| | - Stéfanie Menezes Moura
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil
| | - Maria Cristina Mattar Silva
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil
| | - Carolina Vianna Morgante
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil; Embrapa Semi-Arid, Pretrolina, PE 56302-970, Brazil
| | - Nelson Geraldo Oliveira
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil
| | - Marcos Fernando Basso
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil
| | - Maria Fatima Grossi-de-Sa
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil; Graduate Program in Genomic Science and Biotechnology, Catholic University of Brasília, Brasília, DF 71966-700, Brazil; Graduate Program in Biotechnology, Catholic University Dom Bosco, Campo Grande, MS 79117-900, Brazil.
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Titball RW. The Molecular Architecture and Mode of Action of Clostridium perfringens ε-Toxin. Toxins (Basel) 2024; 16:180. [PMID: 38668605 PMCID: PMC11053738 DOI: 10.3390/toxins16040180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2024] [Revised: 03/31/2024] [Accepted: 04/02/2024] [Indexed: 04/29/2024] Open
Abstract
Clostridium perfringens ε-toxin has long been associated with a severe enterotoxaemia of livestock animals, and more recently, was proposed to play a role in the etiology of multiple sclerosis in humans. The remarkable potency of the toxin has intrigued researchers for many decades, who suggested that this indicated an enzymatic mode of action. Recently, there have been major breakthroughs by finding that it is a pore-forming toxin which shows exquisite specificity for cells bearing the myelin and lymphocyte protein (MAL) receptor. This review details the molecular structures of the toxin, the evidence which identifies MAL as the receptor and the possible roles of other cell membrane components in toxin binding. The information on structure and mode of action has allowed the functions of individual amino acids to be investigated and has led to the creation of mutants with reduced toxicity that could serve as vaccines. In spite of this progress, there are still a number of key questions around the mode of action of the toxin which need to be further investigated.
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Sakaguchi Y, Kobayashi K, Takehara M, Nagahama M. Clostridium perfringens epsilon-toxin requires acid sphingomyelinase for cellular entry. Anaerobe 2023; 82:102753. [PMID: 37308057 DOI: 10.1016/j.anaerobe.2023.102753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 06/08/2023] [Accepted: 06/09/2023] [Indexed: 06/14/2023]
Abstract
OBJECTIVES Clostridium perfringens epsilon-toxin is considered to be a crucial agent in enterotoxemia in domestic animals. Epsilon-toxin enters host cells via endocytosis and results in the formation of late endosome/lysosome-derived vacuoles. In the present study, we found that acid sphingomyelinase promotes the internalization of epsilon-toxin in MDCK cells. METHODS We measured the extracellular release of acid sphingomyelinase (ASMase) by epsilon-toxin. We examined the role of ASMase in epsilon-toxin-induced cytotoxicity using selective inhibitors and knockdown of ASMase. Production of ceramide after toxin treatment was determined by immunofluorescence technique. RESULTS Blocking agents of ASMase and exocytosis of lysosomes inhibited this epsilon-toxin-induced vacuole formation. Lysosomal ASMase was liberated to extracellular space during treatment of the cells with epsilon-toxin in the presence of Ca2+. RNAi-mediated attenuation of ASMase blocked epsilon-toxin-induced vacuolation. Moreover, incubation of MDCK cells with epsilon-toxin led to production of ceramide. The ceramide colocalized with lipid raft-binding cholera toxin subunit B (CTB) in the cell membrane, indicating that conversion of lipid raft associated sphingomyelin to ceramide by ASMase facilitates lesion of MDCK cells and internalization of epsilon-toxin. CONCLUSIONS Based on the present results, ASMase is required for efficient internalization of epsilon-toxin.
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Affiliation(s)
- Yoshihiko Sakaguchi
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho 180, Tokushima, 770-8514, Japan
| | - Keiko Kobayashi
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho 180, Tokushima, 770-8514, Japan
| | - Masaya Takehara
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho 180, Tokushima, 770-8514, Japan
| | - Masahiro Nagahama
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho 180, Tokushima, 770-8514, Japan.
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Du J, Wang T, Xu L, Wang C, Liu Y, Pan C, Chen X, Zhu Z, Luo Y, Yin C. Clostridium perfringens epsilon prototoxin mutant rpETX Y30A/Y71A/H106P/Y196A as a vaccine candidate against enterotoxemia. Vaccine 2023:S0264-410X(23)00719-3. [PMID: 37357076 DOI: 10.1016/j.vaccine.2023.06.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 06/08/2023] [Accepted: 06/12/2023] [Indexed: 06/27/2023]
Abstract
Epsilon toxin (ETX) is secreted by Clostridium perfringens (C. perfringens)as a relatively inactive prototoxin (pETX), which is enzymatically activated to ETX by removing carboxy-terminal and amino-terminal peptides. Genetically engineered ETX mutants have been shown to function as potential vaccine candidates in the prevention of the enterotoxemia caused by C. perfringens. In the present study, two recombinant site-directed mutants of pETX, rpETXY30A/Y71A/H106P/Y196A (rpETXm41) and rpETXY30A/H106P/Y196A/F199E (rpETXm42), were synthesized by mutating four essential amino acid residues (Tyr30, Tyr71, His106, Tyr196 or Phe199). Compared to recombinant pETX (rpETX), both rpETXm41 and rpETXm42 lacked the detectable toxicity in MDCK cells and mice, which suggested that both rpETXm41 and rpETXm42 are sufficiently safe to be vaccine candidates. Despite the fact that rpETXm41 and rpETXm42 were reactogenic with polyclonal antibodies against crude ETX, both single- and double-dose vaccination (Vs and Vd, respectively) of rpETXm41 induced a higher level of IgG titer and protection in mice than that of rpETXm42. Therefore, we selected rpETXm41 for the further study. Sheep received Vs of 150 μg rpETXm41 developed significant levels of toxin-neutralizing antibodies persisting for at least 6 months, which conferred protection against crude ETX challenge without microscopic lesions. These data suggest that genetically detoxified rpETXY30A/Y71A/H106P/Y196A could form the basis of a next-generation enterotoxemia vaccine.
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Affiliation(s)
- Jige Du
- China Institute of Veterinary Drug Control, Beijing, PR China.
| | - Tuanjie Wang
- China Institute of Veterinary Drug Control, Beijing, PR China
| | - Lei Xu
- China Institute of Veterinary Drug Control, Beijing, PR China
| | - Cong Wang
- China Animal Husbandry Industry Co., Ltd., Beijing 100070, PR China
| | - Ying Liu
- China Institute of Veterinary Drug Control, Beijing, PR China
| | - Chenfan Pan
- China Institute of Veterinary Drug Control, Beijing, PR China
| | - Xiaoyun Chen
- China Institute of Veterinary Drug Control, Beijing, PR China
| | - Zhen Zhu
- China Institute of Veterinary Drug Control, Beijing, PR China
| | - Yufeng Luo
- China Institute of Veterinary Drug Control, Beijing, PR China
| | - Chunsheng Yin
- China Institute of Veterinary Drug Control, Beijing, PR China.
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Dorca-Arévalo J, Gómez de Aranda I, Blasi J. New Mutants of Epsilon Toxin from Clostridium perfringens with an Altered Receptor-Binding Site and Cell-Type Specificity. Toxins (Basel) 2022; 14:toxins14040288. [PMID: 35448898 PMCID: PMC9031233 DOI: 10.3390/toxins14040288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 04/08/2022] [Accepted: 04/09/2022] [Indexed: 02/01/2023] Open
Abstract
Epsilon toxin (Etx) from Clostridium perfringens is the third most potent toxin after the botulinum and tetanus toxins. Etx is the main agent of enterotoxemia in ruminants and is produced by Clostridium perfringens toxinotypes B and D, causing great economic losses. Etx selectively binds to target cells, oligomerizes and inserts into the plasma membrane, and forms pores. A series of mutants have been previously generated to understand the cellular and molecular mechanisms of the toxin and to obtain valid molecular tools for effective vaccination protocols. Here, two new non-toxic Etx mutants were generated by selective deletions in the binding (Etx-ΔS188-F196) or insertion (Etx-ΔV108-F135) domains of the toxin. As expected, our results showed that Etx-ΔS188-F196 did not exhibit the usual Etx binding pattern but surprisingly recognized specifically an O-glycoprotein present in the proximal tubules of the kidneys in a wide range of animals, including ruminants. Although diminished, Etx-ΔV108-F135 maintained the capacity for binding and even oligomerization, indicating that the mutation particularly affected the pore-forming ability of the toxin.
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Affiliation(s)
- Jonatan Dorca-Arévalo
- Department of Pathology and Experimental Therapeutics, Faculty of Medicine and Health Sciences, Campus of Bellvitge, University of Barcelona, Hospitalet de Llobregat, 08907 Barcelona, Spain; (I.G.d.A.); (J.B.)
- Biomedical Research Institute of Bellvitge (IDIBELL), L’Hospitalet de Llobregat, 08908 Barcelona, Spain
- Correspondence:
| | - Inmaculada Gómez de Aranda
- Department of Pathology and Experimental Therapeutics, Faculty of Medicine and Health Sciences, Campus of Bellvitge, University of Barcelona, Hospitalet de Llobregat, 08907 Barcelona, Spain; (I.G.d.A.); (J.B.)
| | - Juan Blasi
- Department of Pathology and Experimental Therapeutics, Faculty of Medicine and Health Sciences, Campus of Bellvitge, University of Barcelona, Hospitalet de Llobregat, 08907 Barcelona, Spain; (I.G.d.A.); (J.B.)
- Biomedical Research Institute of Bellvitge (IDIBELL), L’Hospitalet de Llobregat, 08908 Barcelona, Spain
- Institute of Neurosciences, University of Barcelona, 08035 Barcelona, Spain
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Lata K, Singh M, Chatterjee S, Chattopadhyay K. Membrane Dynamics and Remodelling in Response to the Action of the Membrane-Damaging Pore-Forming Toxins. J Membr Biol 2022; 255:161-173. [PMID: 35305136 DOI: 10.1007/s00232-022-00227-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 03/02/2022] [Indexed: 12/11/2022]
Abstract
Pore-forming protein toxins (PFTs) represent a diverse class of membrane-damaging proteins that are produced by a wide variety of organisms. PFT-mediated membrane perforation is largely governed by the chemical composition and the physical properties of the plasma membranes. The interaction between the PFTs with the target membranes is critical for the initiation of the pore-formation process, and can lead to discrete membrane reorganization events that further aids in the process of pore-formation. Punching holes on the plasma membranes by the PFTs interferes with the cellular homeostasis by disrupting the ion-balance inside the cells that in turn can turn on multiple signalling cascades required to restore membrane integrity and cellular homeostasis. In this review, we discuss the physicochemical attributes of the plasma membranes associated with the pore-formation processes by the PFTs, and the subsequent membrane remodelling events that may start off the membrane-repair mechanisms.
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Affiliation(s)
- Kusum Lata
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Manauli, Mohali, Punjab, 140306, India
| | - Mahendra Singh
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Manauli, Mohali, Punjab, 140306, India
| | - Shamaita Chatterjee
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Manauli, Mohali, Punjab, 140306, India
| | - Kausik Chattopadhyay
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Manauli, Mohali, Punjab, 140306, India.
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Ulhuq FR, Mariano G. Bacterial pore-forming toxins. MICROBIOLOGY (READING, ENGLAND) 2022; 168:001154. [PMID: 35333704 PMCID: PMC9558359 DOI: 10.1099/mic.0.001154] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 02/03/2022] [Indexed: 12/11/2022]
Abstract
Pore-forming toxins (PFTs) are widely distributed in both Gram-negative and Gram-positive bacteria. PFTs can act as virulence factors that bacteria utilise in dissemination and host colonisation or, alternatively, they can be employed to compete with rival microbes in polymicrobial niches. PFTs transition from a soluble form to become membrane-embedded by undergoing large conformational changes. Once inserted, they perforate the membrane, causing uncontrolled efflux of ions and/or nutrients and dissipating the protonmotive force (PMF). In some instances, target cells intoxicated by PFTs display additional effects as part of the cellular response to pore formation. Significant progress has been made in the mechanistic description of pore formation for the different PFTs families, but in several cases a complete understanding of pore structure remains lacking. PFTs have evolved recognition mechanisms to bind specific receptors that define their host tropism, although this can be remarkably diverse even within the same family. Here we summarise the salient features of PFTs and highlight where additional research is necessary to fully understand the mechanism of pore formation by members of this diverse group of protein toxins.
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Affiliation(s)
- Fatima R. Ulhuq
- Microbes in Health and Disease Theme, Newcastle University Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Giuseppina Mariano
- Microbes in Health and Disease Theme, Newcastle University Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
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9
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Kouadio JL, Duff S, Aikins M, Zheng M, Rydel T, Chen D, Bretsnyder E, Xia C, Zhang J, Milligan J, Evdokimov A, Nageotte J, Yin Y, Moar W, Giddings K, Park Y, Jerga A, Haas J. Structural and functional characterization of Mpp75Aa1.1, a putative beta-pore forming protein from Brevibacillus laterosporus active against the western corn rootworm. PLoS One 2021; 16:e0258052. [PMID: 34634061 PMCID: PMC8504720 DOI: 10.1371/journal.pone.0258052] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 09/16/2021] [Indexed: 12/16/2022] Open
Abstract
The western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, is a major corn pest of significant economic importance in the United States. The continuous need to control this corn maize pest and the development of field-evolved resistance toward all existing transgenic maize (Zea mays L.) expressing Bacillus thuringiensis (Bt) insecticidal proteins against WCR has prompted the development of new insect-protected crops expressing distinct structural classes of insecticidal proteins. In this current study, we describe the crystal structure and functional characterization of Mpp75Aa1.1, which represents the first corn rootworm (CRW) active insecticidal protein member of the ETX_MTX2 sub-family of beta-pore forming proteins (β-PFPs), and provides new and effective protection against WCR feeding. The Mpp75Aa1.1 crystal structure was solved at 1.94 Å resolution. The Mpp75Aa1.1 is processed at its carboxyl-terminus by WCR midgut proteases, forms an oligomer, and specifically interacts with putative membrane-associated binding partners on the midgut apical microvilli to cause cellular tissue damage resulting in insect death. Alanine substitution of the surface-exposed amino acids W206, Y212, and G217 within the Mpp75Aa1.1 putative receptor binding domain I demonstrates that at least these three amino acids are required for WCR activity. The distinctive spatial arrangement of these amino acids suggests that they are part of a receptor binding epitope, which may be unique to Mpp75Aa1.1 and not present in other ETX_MTX2 proteins that do not have WCR activity. Overall, this work establishes that Mpp75Aa1.1 shares a mode of action consistent with traditional WCR-active Bt proteins despite significant structural differences.
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Affiliation(s)
- Jean-Louis Kouadio
- Bayer Crop Science, Chesterfield, Missouri, United States of America
- * E-mail:
| | - Stephen Duff
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Michael Aikins
- Department of Entomology, Kansas State University, Manhattan, Kansas, United States of America
| | - Meiying Zheng
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Timothy Rydel
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Danqi Chen
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Eric Bretsnyder
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Chunsheng Xia
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Jun Zhang
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Jason Milligan
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Artem Evdokimov
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Jeffrey Nageotte
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Yong Yin
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - William Moar
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Kara Giddings
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Yoonseong Park
- Department of Entomology, Kansas State University, Manhattan, Kansas, United States of America
| | - Agoston Jerga
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Jeffrey Haas
- Bayer Crop Science, Chesterfield, Missouri, United States of America
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10
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Alimolaei M, Golchin M, Baluch-Akbari A. Immunogenicity of a recombinant Lactobacillus casei, surface-expressed H 151P mutant of Clostridium perfringens epsilon toxin and its protective responses in BALB/c mice. Toxicon 2021; 200:173-179. [PMID: 34324946 DOI: 10.1016/j.toxicon.2021.07.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 06/24/2021] [Accepted: 07/22/2021] [Indexed: 11/17/2022]
Abstract
Epsilon toxin (Etx) is the most important virulence factor of type D C. perfringens in ruminants. The recombinant vaccines can be used against Etx intoxication. This study aimed to investigate the humoral immune responses of mice against a recombinant Lactobacillus casei which surface-expressed H151P mutant of Etx (L. casei-ε) after oral and parenteral immunization routes. The protective immunity was determined by challenge with trypsin-activated Etx. Higher humoral immune responses were seen in parenterally vaccinated mice with Freund's-adjuvanted L. casei-ε than non-adjuvanted and negative controls (P<0.05). In the oral immunized mice, L. casei-ε displayed a significant difference in IgG titres compared with the negative controls. Challenge results showed full protection of oral immunized mice against one and two MLDs, and partial protection against 10 MLD of the trypsin-activated Etx, whereas, the parenteral immunized mice only induced 75 % of protection against one MLD. This may be related to the appropriate immunity responses by L. casei-ε at the mucosal surfaces, which highlights the role of the oral immunization. Thus, L. casei-ε can be considered as an oral vaccine candidate against Etx intoxication and enterotoxaemia.
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Affiliation(s)
- Mojtaba Alimolaei
- Department of Research and Technology, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Kerman Branch, Kerman, Iran.
| | - Mehdi Golchin
- Department of Pathobiology, Faculty of Veterinary Medicine, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Amin Baluch-Akbari
- Faculty of Veterinary Medicine, Shahid Bahonar University of Kerman, Kerman, Iran
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11
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Pinaud S, Tetreau G, Poteaux P, Galinier R, Chaparro C, Lassalle D, Portet A, Simphor E, Gourbal B, Duval D. New Insights Into Biomphalysin Gene Family Diversification in the Vector Snail Biomphalaria glabrata. Front Immunol 2021; 12:635131. [PMID: 33868258 PMCID: PMC8047071 DOI: 10.3389/fimmu.2021.635131] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Accepted: 03/08/2021] [Indexed: 11/30/2022] Open
Abstract
Aerolysins initially characterized as virulence factors in bacteria are increasingly found in massive genome and transcriptome sequencing data from metazoans. Horizontal gene transfer has been demonstrated as the main way of aerolysin-related toxins acquisition in metazoans. However, only few studies have focused on their potential biological functions in such organisms. Herein, we present an extensive characterization of a multigene family encoding aerolysins - named biomphalysin - in Biomphalaria glabrata snail, the intermediate host of the trematode Schistosoma mansoni. Our results highlight that duplication and domestication of an acquired bacterial toxin gene in the snail genome result in the acquisition of a novel and diversified toxin family. Twenty-three biomphalysin genes were identified. All are expressed and exhibited a tissue-specific expression pattern. An in silico structural analysis was performed to highlight the central role played by two distinct domains i) a large lobe involved in the lytic function of these snail toxins which constrained their evolution and ii) a small lobe which is structurally variable between biomphalysin toxins and that matched to various functional domains involved in moiety recognition of targets cells. A functional approach suggests that the repertoire of biomphalysins that bind to pathogens, depends on the type of pathogen encountered. These results underline a neo-and sub-functionalization of the biomphalysin toxins, which have the potential to increase the range of effectors in the snail’s immune arsenal.
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Affiliation(s)
- Silvain Pinaud
- IHPE, Univ Montpellier, CNRS, IFREMER, Univ Perpignan Via Domitia, Perpignan, France.,CNRS, IFREMER, University of Montpellier, Perpignan, France
| | - Guillaume Tetreau
- IHPE, Univ Montpellier, CNRS, IFREMER, Univ Perpignan Via Domitia, Perpignan, France.,CNRS, IFREMER, University of Montpellier, Perpignan, France
| | - Pierre Poteaux
- IHPE, Univ Montpellier, CNRS, IFREMER, Univ Perpignan Via Domitia, Perpignan, France.,CNRS, IFREMER, University of Montpellier, Perpignan, France
| | - Richard Galinier
- IHPE, Univ Montpellier, CNRS, IFREMER, Univ Perpignan Via Domitia, Perpignan, France.,CNRS, IFREMER, University of Montpellier, Perpignan, France
| | - Cristian Chaparro
- IHPE, Univ Montpellier, CNRS, IFREMER, Univ Perpignan Via Domitia, Perpignan, France.,CNRS, IFREMER, University of Montpellier, Perpignan, France
| | - Damien Lassalle
- IHPE, Univ Montpellier, CNRS, IFREMER, Univ Perpignan Via Domitia, Perpignan, France.,CNRS, IFREMER, University of Montpellier, Perpignan, France
| | - Anaïs Portet
- IHPE, Univ Montpellier, CNRS, IFREMER, Univ Perpignan Via Domitia, Perpignan, France.,CNRS, IFREMER, University of Montpellier, Perpignan, France
| | - Elodie Simphor
- IHPE, Univ Montpellier, CNRS, IFREMER, Univ Perpignan Via Domitia, Perpignan, France.,CNRS, IFREMER, University of Montpellier, Perpignan, France
| | - Benjamin Gourbal
- IHPE, Univ Montpellier, CNRS, IFREMER, Univ Perpignan Via Domitia, Perpignan, France.,CNRS, IFREMER, University of Montpellier, Perpignan, France
| | - David Duval
- IHPE, Univ Montpellier, CNRS, IFREMER, Univ Perpignan Via Domitia, Perpignan, France.,CNRS, IFREMER, University of Montpellier, Perpignan, France
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12
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Branching out the aerolysin, ETX/MTX-2 and Toxin_10 family of pore forming proteins. J Invertebr Pathol 2021; 186:107570. [PMID: 33775676 DOI: 10.1016/j.jip.2021.107570] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 12/15/2020] [Accepted: 03/09/2021] [Indexed: 01/28/2023]
Abstract
Organisms have evolved mechanisms in which cellular membranes can both be targeted and punctured thereby killing the targeted cell. One such mechanism involves the deployment of pore forming proteins (PFPs) which function by oligomerizing on cell membranes and inserting a physical pore spanning the membrane. This pore can lead to cell death by either causing osmotic flux or allowing the delivery of a secondary toxin. Pore forming proteins can be broadly classified into different families depending on the structure of the final pore; either α-PFPs using channels made from α -helices or β-PFPs using channels made from β-barrels. There are many different β-PFPs and an emerging superfamily is the aerolysin-ETX/MTX-2 superfamily. A comparison between the members of this superfamily reveals the pore forming domain is a common module yet the receptor binding region is highly variable. These structural and architectural variations lead to differences in the target recognition and determine the site of activity. Closer investigation of the topology of the family also suggests that the Toxin_10 family of PFPs could be considered as part of the aerolysin-ETX/MTX-2 superfamily. Comparatively, far less is known about how Toxin_10 proteins assemble into the final pore structure than aerolysin-ETX/MTX-2 proteins. This review aims to collate the pore forming protein members and bridge the structural similarities between the aerolysin-ETX/MTX-2 superfamily and the insecticidal Toxin_10 subfamily.
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13
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Li Y, Li Y, Mengist HM, Shi C, Zhang C, Wang B, Li T, Huang Y, Xu Y, Jin T. Structural Basis of the Pore-Forming Toxin/Membrane Interaction. Toxins (Basel) 2021; 13:toxins13020128. [PMID: 33572271 PMCID: PMC7914777 DOI: 10.3390/toxins13020128] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 01/13/2021] [Accepted: 02/02/2021] [Indexed: 12/14/2022] Open
Abstract
With the rapid growth of antibiotic-resistant bacteria, it is urgent to develop alternative therapeutic strategies. Pore-forming toxins (PFTs) belong to the largest family of virulence factors of many pathogenic bacteria and constitute the most characterized classes of pore-forming proteins (PFPs). Recent studies revealed the structural basis of several PFTs, both as soluble monomers, and transmembrane oligomers. Upon interacting with host cells, the soluble monomer of bacterial PFTs assembles into transmembrane oligomeric complexes that insert into membranes and affect target cell-membrane permeability, leading to diverse cellular responses and outcomes. Herein we have reviewed the structural basis of pore formation and interaction of PFTs with the host cell membrane, which could add valuable contributions in comprehensive understanding of PFTs and searching for novel therapeutic strategies targeting PFTs and interaction with host receptors in the fight of bacterial antibiotic-resistance.
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Affiliation(s)
- Yajuan Li
- Department of Clinical Laboratory, the First Affiliated Hospital of Anhui Medical University, Hefei 230022, China; (Y.L.); (C.S.); (B.W.); (T.L.); (Y.H.)
| | - Yuelong Li
- Hefei National Laboratory for Physical Sciences at Microscale, Laboratory of Structural Immunology, CAS Key Laboratory of Innate Immunity and Chronic Disease, Division of Life Sciences and Medicine, School of Basic Medical Sciences, University of Science and Technology of China, Hefei 230027, China; (Y.L.); (H.M.M.); (C.Z.)
| | - Hylemariam Mihiretie Mengist
- Hefei National Laboratory for Physical Sciences at Microscale, Laboratory of Structural Immunology, CAS Key Laboratory of Innate Immunity and Chronic Disease, Division of Life Sciences and Medicine, School of Basic Medical Sciences, University of Science and Technology of China, Hefei 230027, China; (Y.L.); (H.M.M.); (C.Z.)
| | - Cuixiao Shi
- Department of Clinical Laboratory, the First Affiliated Hospital of Anhui Medical University, Hefei 230022, China; (Y.L.); (C.S.); (B.W.); (T.L.); (Y.H.)
| | - Caiying Zhang
- Hefei National Laboratory for Physical Sciences at Microscale, Laboratory of Structural Immunology, CAS Key Laboratory of Innate Immunity and Chronic Disease, Division of Life Sciences and Medicine, School of Basic Medical Sciences, University of Science and Technology of China, Hefei 230027, China; (Y.L.); (H.M.M.); (C.Z.)
| | - Bo Wang
- Department of Clinical Laboratory, the First Affiliated Hospital of Anhui Medical University, Hefei 230022, China; (Y.L.); (C.S.); (B.W.); (T.L.); (Y.H.)
| | - Tingting Li
- Department of Clinical Laboratory, the First Affiliated Hospital of Anhui Medical University, Hefei 230022, China; (Y.L.); (C.S.); (B.W.); (T.L.); (Y.H.)
| | - Ying Huang
- Department of Clinical Laboratory, the First Affiliated Hospital of Anhui Medical University, Hefei 230022, China; (Y.L.); (C.S.); (B.W.); (T.L.); (Y.H.)
| | - Yuanhong Xu
- Department of Clinical Laboratory, the First Affiliated Hospital of Anhui Medical University, Hefei 230022, China; (Y.L.); (C.S.); (B.W.); (T.L.); (Y.H.)
- Correspondence: (Y.X.); (T.J.); Tel.: +86-13505694447 (Y.X.); +86-17605607323 (T.J.)
| | - Tengchuan Jin
- Hefei National Laboratory for Physical Sciences at Microscale, Laboratory of Structural Immunology, CAS Key Laboratory of Innate Immunity and Chronic Disease, Division of Life Sciences and Medicine, School of Basic Medical Sciences, University of Science and Technology of China, Hefei 230027, China; (Y.L.); (H.M.M.); (C.Z.)
- Correspondence: (Y.X.); (T.J.); Tel.: +86-13505694447 (Y.X.); +86-17605607323 (T.J.)
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14
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Etx-Y71A as a non-toxic mutant of Clostridium perfringens epsilon toxin induces protective immunity in mice and sheep. Vaccine 2020; 38:6553-6561. [PMID: 32788135 DOI: 10.1016/j.vaccine.2020.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 07/25/2020] [Accepted: 08/03/2020] [Indexed: 11/21/2022]
Abstract
Epsilon toxin (Etx) is an extremely potent toxin produced by Clostridium perfringens toxinotypes B and D, which cause fatal enterotoxemia in many livestock species, mainly sheep and goats. Our previous study demonstrated that the aromatic amino acid (AA) residue at position 71 in domain III of Etx is needed for its cytotoxic activity toward MDCK cells. Here, we first determined that Etx mutants with non-aromatic AA substitutions at Tyr71 lost lethality in mice, indicating that the aromatic AA residue at position 71 is a toxicity determinant of Etx in vivo. After intravenous injection with a high dose of the trypsin-activated Etx-Y71A mutant, mice did not show any histopathological lesions, and confocal microscopy observations further showed that Etx-Y71A lost the ability to cross the blood-brain barrier of the mice. These results suggested that the Etx-Y71A mutant is sufficiently safe in vivo to be a vaccine candidate. Furthermore, the immune efficacy of Etx-Y71A was evaluated in model and host animals. Mice inoculated with this mutant produced high levels of neutralizing antibodies and were completely protected from a 100 LD50 of trypsin-activated Etx challenge. Sheep immunized with Etx-Y71A produced high levels of neutralizing antibodies that provided protection in mice against an activated Etx challenge, and lambs could receive passive immunity through immunization of pregnant ewes. Additionally, homology modeling and circular dichroism analysis showed that Etx-Y71A has structural similarity to Etx, which provides a structural basis for Etx-Y71A retaining the immunogenicity of Etx. Taken together, these results suggest that Etx-Y71A is a potential vaccine candidate against Etx-inducing enterotoxemia.
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15
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Clostridium perfringens Epsilon-Toxin Impairs the Barrier Function in MDCK Cell Monolayers in a Ca 2+-Dependent Manner. Toxins (Basel) 2020; 12:toxins12050286. [PMID: 32365779 PMCID: PMC7291203 DOI: 10.3390/toxins12050286] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 04/21/2020] [Accepted: 04/28/2020] [Indexed: 12/27/2022] Open
Abstract
Epsilon-toxin produced by Clostridium perfringens significantly contributes to the pathogeneses of enterotoxemia in ruminants and multiple sclerosis in humans. Epsilon-toxin forms a heptameric oligomer in the host cell membrane, promoting cell disruption. Here, we investigate the effect of epsilon-toxin on epithelial barrier functions. Epsilon-toxin impairs the barrier integrity of Madin-Darby Canine Kidney (MDCK) cells, as demonstrated by decreased transepithelial electrical resistance (TEER), increased paracellular flux marker permeability, and the decreased cellular localization of junctional proteins, such as occludin, ZO-1, and claudin-1. U73122, an endogenous phospholipase C (PLC) inhibitor, inhibited the decrease in TEER and the increase in the permeability of flux marker induced by epsilon-toxin. The application of epsilon-toxin to MDCK cells resulted in the biphasic formation of 1,2-diacylglycerol (DAG) and inositol-1,4,5-triphosphate (IP3). U73122 blocked the formation of DAG and IP3 induced by the toxin. Epsilon-toxin also specifically activated endogenous PLC-γ1. Epsilon-toxin dose-dependently increased the cytosolic calcium ion concentration ([Ca2+]i). The toxin-induced elevation of [Ca2+]i was inhibited by U73122. Cofilin is a key regulator of actin cytoskeleton turnover and tight-junction (TJ) permeability regulation. Epsilon-toxin caused cofilin dephosphorylation. These results demonstrate that epsilon-toxin induces Ca2+ influx through activating the phosphorylation of PLC-γ1 and then causes TJ opening accompanied by cofilin dephosphorylation.
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16
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Lassalle D, Tetreau G, Pinaud S, Galinier R, Crickmore N, Gourbal B, Duval D. Glabralysins, Potential New β-Pore-Forming Toxin Family Members from the Schistosomiasis Vector Snail Biomphalaria glabrata. Genes (Basel) 2020; 11:genes11010065. [PMID: 31936048 PMCID: PMC7016736 DOI: 10.3390/genes11010065] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 12/20/2019] [Accepted: 12/27/2019] [Indexed: 12/11/2022] Open
Abstract
Biomphalaria glabrata is a freshwater Planorbidae snail. In its environment, this mollusk faces numerous microorganisms or pathogens, and has developed sophisticated innate immune mechanisms to survive. The mechanisms of recognition are quite well understood in Biomphalaria glabrata, but immune effectors have been seldom described. In this study, we analyzed a new family of potential immune effectors and characterized five new genes that were named Glabralysins. The five Glabralysin genes showed different genomic structures and the high degree of amino acid identity between the Glabralysins, and the presence of the conserved ETX/MTX2 domain, support the hypothesis that they are pore-forming toxins. In addition, tertiary structure prediction confirms that they are structurally related to a subset of Cry toxins from Bacillus thuringiensis, including Cry23, Cry45, and Cry51. Finally, we investigated their gene expression profiles in snail tissues and demonstrated a mosaic transcription. We highlight the specificity in Glabralysin expression following immune stimulation with bacteria, yeast or trematode parasites. Interestingly, one Glabralysin was found to be expressed in immune-specialized hemocytes, and two others were induced following parasite exposure.
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Affiliation(s)
- Damien Lassalle
- IHPE, University of Montpellier, CNRS, Ifremer, University of Perpignan Via Domitia, 66860 Perpignan France; (D.L.); (G.T.); (S.P.); (R.G.); (B.G.)
| | - Guillaume Tetreau
- IHPE, University of Montpellier, CNRS, Ifremer, University of Perpignan Via Domitia, 66860 Perpignan France; (D.L.); (G.T.); (S.P.); (R.G.); (B.G.)
| | - Silvain Pinaud
- IHPE, University of Montpellier, CNRS, Ifremer, University of Perpignan Via Domitia, 66860 Perpignan France; (D.L.); (G.T.); (S.P.); (R.G.); (B.G.)
| | - Richard Galinier
- IHPE, University of Montpellier, CNRS, Ifremer, University of Perpignan Via Domitia, 66860 Perpignan France; (D.L.); (G.T.); (S.P.); (R.G.); (B.G.)
| | - Neil Crickmore
- School of Life Sciences, University of Sussex, Brighton BN1 9RH, UK;
| | - Benjamin Gourbal
- IHPE, University of Montpellier, CNRS, Ifremer, University of Perpignan Via Domitia, 66860 Perpignan France; (D.L.); (G.T.); (S.P.); (R.G.); (B.G.)
| | - David Duval
- IHPE, University of Montpellier, CNRS, Ifremer, University of Perpignan Via Domitia, 66860 Perpignan France; (D.L.); (G.T.); (S.P.); (R.G.); (B.G.)
- Correspondence:
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17
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18
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Clostridium perfringens epsilon toxin vaccine candidate lacking toxicity to cells expressing myelin and lymphocyte protein. NPJ Vaccines 2019; 4:32. [PMID: 31372245 PMCID: PMC6667452 DOI: 10.1038/s41541-019-0128-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Accepted: 07/10/2019] [Indexed: 02/07/2023] Open
Abstract
A variant form of Clostridium perfringens epsilon toxin (Y30A-Y196A) with mutations, which shows reduced binding to Madin–Darby canine kidney (MDCK) cells and reduced toxicity in mice, has been proposed as the next-generation enterotoxaemia vaccine. Here we show that, unexpectedly, the Y30A-Y196A variant does not show a reduction in toxicity towards Chinese hamster ovary (CHO) cells engineered to express the putative receptor for the toxin (myelin and lymphocyte protein; MAL). The further addition of mutations to residues in a second putative receptor binding site of the Y30A-Y196A variant further reduces toxicity, and we selected Y30A-Y196A-A168F for further study. Compared to Y30A-Y196A, Y30A-Y196A-A168F showed more than a 3-fold reduction in toxicity towards MDCK cells, more than a 4-fold reduction in toxicity towards mice and at least 200-fold reduction in toxicity towards CHO cells expressing sheep MAL. The immunisation of rabbits or sheep with Y30A-Y196A-A168F induced high levels of neutralising antibodies against epsilon toxin, which persisted for at least 1 year. Y30A-Y196A-A168F is a candidate for development as a next-generation enterotoxaemia vaccine. Cells expressing myelin and lymphocyte protein (MAL), the putative receptor for Clostridium perfringens’ epsilon toxin, can be sensitive to otherwise attenuated mutants of the toxin. Here, the team led by Richard Titball at United Kingdom’s University of Exeter found that a previous variant exhibits differential toxic effects when cells express sheep or human MAL. To circumvent this, Titball’s team applied site-directed mutagenesis of the receptor binding site to develop a new variant with enhanced reduction in toxicity towards MAL-expressing cells and able to induce high levels of neutralising antibodies upon immunisation of sheep. These findings suggests that testing genetic toxoids in cells expressing MAL from the target species might be relevant for enterotoxaemia vaccine development and warrant further studies into the role of MAL in epsilon toxin-mediated pathogenesis.
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19
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Savva CG, Clark AR, Naylor CE, Popoff MR, Moss DS, Basak AK, Titball RW, Bokori-Brown M. The pore structure of Clostridium perfringens epsilon toxin. Nat Commun 2019; 10:2641. [PMID: 31201325 PMCID: PMC6572795 DOI: 10.1038/s41467-019-10645-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 05/20/2019] [Indexed: 12/25/2022] Open
Abstract
Epsilon toxin (Etx), a potent pore forming toxin (PFT) produced by Clostridium perfringens, is responsible for the pathogenesis of enterotoxaemia of ruminants and has been suggested to play a role in multiple sclerosis in humans. Etx is a member of the aerolysin family of β-PFTs (aβ-PFTs). While the Etx soluble monomer structure was solved in 2004, Etx pore structure has remained elusive due to the difficulty of isolating the pore complex. Here we show the cryo-electron microscopy structure of Etx pore assembled on the membrane of susceptible cells. The pore structure explains important mutant phenotypes and suggests that the double β-barrel, a common feature of the aβ-PFTs, may be an important structural element in driving efficient pore formation. These insights provide the framework for the development of novel therapeutics to prevent human and animal infections, and are relevant for nano-biotechnology applications. Epsilon toxin (Etx) is a potent pore forming toxin (PFT) produced by Clostridium perfringens. Here authors show the cryo-EM structure of the Etx pore assembled on the membrane of susceptible cells and shed light on pore formation and mutant phenotypes.
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Affiliation(s)
- Christos G Savva
- Leicester Institute of Structural and Chemical Biology, Department of Molecular and Cell Biology, University of Leicester, Lancaster Road, Leicester, LE1 7HB, UK
| | - Alice R Clark
- Faculty of Science and Engineering, University of Wolverhampton, Wulfruna Street, Wolverhampton, WV1 1LY, UK
| | - Claire E Naylor
- Molecular Dimensions, Willie Snaith Road, Newmarket, CB8 7SQ, UK
| | - Michel R Popoff
- Bactéries Anaérobies et Toxines, Institut Pasteur, 25-28 Rue du Docteur Roux, 75724, Paris Cedex 15, France
| | - David S Moss
- Department of Biological Sciences, Birkbeck College, Malet Street, London, WC1E 7HX, UK
| | - Ajit K Basak
- Department of Biological Sciences, 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
| | - Monika Bokori-Brown
- College of Life and Environmental Sciences, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK.
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20
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Li L, Zhang S, Wu W, Guan W, Deng Z, Qiao H. Enhancing thermostability of Yarrowia lipolytica lipase 2 through engineering multiple disulfide bonds and mitigating reduced lipase production associated with disulfide bonds. Enzyme Microb Technol 2019; 126:41-49. [PMID: 31000163 DOI: 10.1016/j.enzmictec.2019.03.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Revised: 03/21/2019] [Accepted: 03/26/2019] [Indexed: 12/14/2022]
Abstract
The limited thermostability of Yarrowia lipolytica lipase 2 (Lip2) hampers its industrial application. To improve its thermostability, we combined single disulfide bonds which our group identified previously. In this study, combining different regional disulfide bonds had greater effect than combining same regional disulfide bonds. Furthermore, mutants with 4, 5, and 6 disulfide bonds exhibited dramatically enhanced thermostability. Compared with the wild-type, sextuple mutant 6s displayed a 22.53 and 31.23 ℃ increase in the melting temperature (Tm) and the half loss temperature at 15 min (T15 50), respectively, with greater pH stability and a wider reaction pH range. Molecular dynamics simulation revealed that multiple disulfide bonds resulted in more rigid structures of mutants 4s, 5s and 6s, and prolonged enzyme unfolding times. Moreover, secretions of mutants 5s and 6s were significantly increased by 60% and 80% by co-expressing with the chaperone protein disulfide isomerase (PDI), which mitigated the reduced production issue caused by multiple disulfide bonds. Results of this study indicated that enhanced heat endurance giving more potential for industrial application.
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Affiliation(s)
- Lilang Li
- College of Animal Science, South China Agricultural University, Guangzhou 510640, China; Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou 510642, China.
| | - Shihai Zhang
- College of Animal Science, South China Agricultural University, Guangzhou 510640, China; Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou 510642, China.
| | - Weikun Wu
- College of Animal Science, South China Agricultural University, Guangzhou 510640, China; Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - Wutai Guan
- College of Animal Science, South China Agricultural University, Guangzhou 510640, China; Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou 510642, China; College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, China.
| | - Zixiao Deng
- College of Animal Science, South China Agricultural University, Guangzhou 510640, China; Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - Hanzhen Qiao
- College of Animal Science, South China Agricultural University, Guangzhou 510640, China; Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
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21
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Gil C, Dorca-Arévalo J, Blasi J. Calcium enhances binding of Clostridium perfringens epsilon toxin to sulfatide. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1861:161-169. [PMID: 30463699 DOI: 10.1016/j.bbamem.2018.08.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 07/20/2018] [Accepted: 08/07/2018] [Indexed: 01/07/2023]
Abstract
Epsilon toxin (Etx) from Clostridium perfringens is synthesized as a very low-active prototoxin form (proEtx) that becomes active upon proteolytic activation and has the capacity to cross the blood-brain barrier (BBB), thereby producing severe neurological effects. The identity and requirements of host receptors of Etx remain a matter of controversy. In the present study, we analysed the binding of proEtx or Etx to liposomes containing distearoylphosphatidylcholine (DSPC), cholesterol and sulfatide, or alternatively to detergent-solubilized lipids, using surface plasmon resonance (SPR). We also tested the influence of calcium on Etx or proEtx binding. Our findings show that the presence of sulfatide in liposomes increases both Etx and proEtx binding, and Etx binding is enhanced by calcium. These results were corroborated when SPR was conducted with immobilized toxin, since detergent-solubilized sulfatide increases its binding to Etx in the presence of calcium, but not to proEtx. Moreover, binding affinity is also affected, since the treatment of liposomes with sulfatase causes the dissociation rate constants (KD) in both proEtx and Etx to increase, especially in the case of proEtx in the presence of calcium. In addition, protein-lipid overlay assays corroborated the calcium-induced enhancement of Etx binding to sulfatide, and to lipids extracted from sulfatide-enriched rat brain lipid rafts. In conclusion, the present work highlights the role of sulfatide as an important element in the pathophysiology of Etx and reveals the influence of calcium in the interaction of Etx, but not of proEtx, with the target membrane.
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Affiliation(s)
- C Gil
- Departament de Bioquímica i Biologia Molecular, Institut de Neurociències, Universitat Autònoma de Barcelona, Bellaterra, Catalunya, Spain.
| | - J Dorca-Arévalo
- Laboratory of Cellular and Molecular Neurobiology, Department of Pathology and Experimental Therapeutics, School of Medicine, University of Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain; Biomedical Research Institute of Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain; Institut de Neurociències, Universitat de Barcelona, Spain
| | - J Blasi
- Laboratory of Cellular and Molecular Neurobiology, Department of Pathology and Experimental Therapeutics, School of Medicine, University of Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain; Biomedical Research Institute of Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain; Institut de Neurociències, Universitat de Barcelona, Spain
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A Novel Panel of Rabbit Monoclonal Antibodies and Their Diverse Applications Including Inhibition of Clostridium perfringens Epsilon Toxin Oligomerization. Antibodies (Basel) 2018; 7:antib7040037. [PMID: 31544887 PMCID: PMC6698963 DOI: 10.3390/antib7040037] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 10/18/2018] [Accepted: 10/22/2018] [Indexed: 12/18/2022] Open
Abstract
The pore-forming epsilon toxin (ETX) produced by Clostridium perfringens is among the most lethal bacterial toxins known. Sensitive antibody-based reagents are needed to detect toxin, distinguish mechanisms of cell death, and prevent ETX toxicity. Using B-cell immuno-panning and cloning techniques, seven ETX-specific monoclonal antibodies were generated from immunized rabbits. ETX specificity and sensitivity were evaluated via western blot, ELISA, immunocytochemistry (ICC), and flow cytometry. ETX-neutralizing function was evaluated both in vitro and in vivo. All antibodies recognized both purified ETX and epsilon protoxin via western blot with two capable of detecting the ETX-oligomer complex. Four antibodies detected ETX via ELISA and three detected ETX bound to cells via ICC or flow cytometry. Several antibodies prevented ETX-induced cell death by either preventing ETX binding or by blocking ETX oligomerization. Antibodies that blocked ETX oligomerization inhibited ETX endocytosis and cellular vacuolation. Importantly, one of the oligomerization-blocking antibodies was able to protect against ETX-induced death post-ETX exposure in vitro and in vivo. Here we describe the production of a panel of rabbit monoclonal anti-ETX antibodies and their use in various biological assays. Antibodies possessing differential specificity to ETX in particular conformations will aid in the mechanistic studies of ETX cytotoxicity, while those with ETX-neutralizing function may be useful in preventing ETX-mediated mortality.
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Kang J, Gao J, Yao W, Kang L, Gao S, Yang H, Ji B, Li P, Liu J, Yao J, Xin W, Zhao B, Wang J. F199E substitution reduced toxicity of Clostridium perfringens epsilon toxin by depriving the receptor binding capability. Hum Vaccin Immunother 2017; 13:1598-1608. [PMID: 28304231 DOI: 10.1080/21645515.2017.1303022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Epsilon toxin (ETX), a potent toxin, is produced by types B and D strains of Clostridium perfringens, which could cause severe diseases in humans and domestic animals. Mutant rETXF199E was previously demonstrated to be a good vaccine candidate. However, the mechanism concerned remains unknown. To clarify how F199E substitution reduced ETX toxicity, we performed a series of experiments. The results showed that the cell-binding and pore-forming ability of rETXF199E was almost abolished. We speculated that F199E substitution reduced toxicity by depriving the receptor binding capability of ETX, which contributed to the hypothesis that domain I of ETX is responsible for cell binding. In addition, our data suggested that ETX could cause Ca2+ release from intracellular Ca2+ stores, which may underlie an alternate pathway leading to cell death. Furthermore, ETX induced crenation of the MDCK cells was observed, with sags and crests first appearing on the surface of condensed MDCK cells, according to scanning electron microscopy. The data also demonstrated the safety and potentiality of rETXF199E as a vaccine candidate for humans. In summary, findings of this work potentially contribute to a better understanding of the pathogenic mechanism of ETX and the development of vaccine against diseases caused by ETX, using mutant proteins.
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Affiliation(s)
- Jingjing Kang
- a Life Science Institute of Hebei Normal University , Shijiazhuang, Hebei Province , PR China
| | - Jie Gao
- a Life Science Institute of Hebei Normal University , Shijiazhuang, Hebei Province , PR China
| | - Wenwu Yao
- b State Key Laboratory of Pathogen and Biosecurity , Institute of Microbiology and Epidemiology , Beijing , PR China
| | - Lin Kang
- b State Key Laboratory of Pathogen and Biosecurity , Institute of Microbiology and Epidemiology , Beijing , PR China
| | - Shan Gao
- b State Key Laboratory of Pathogen and Biosecurity , Institute of Microbiology and Epidemiology , Beijing , PR China
| | - Hao Yang
- b State Key Laboratory of Pathogen and Biosecurity , Institute of Microbiology and Epidemiology , Beijing , PR China
| | - Bin Ji
- b State Key Laboratory of Pathogen and Biosecurity , Institute of Microbiology and Epidemiology , Beijing , PR China
| | - Ping Li
- b State Key Laboratory of Pathogen and Biosecurity , Institute of Microbiology and Epidemiology , Beijing , PR China
| | - Jing Liu
- b State Key Laboratory of Pathogen and Biosecurity , Institute of Microbiology and Epidemiology , Beijing , PR China
| | - Jiahao Yao
- b State Key Laboratory of Pathogen and Biosecurity , Institute of Microbiology and Epidemiology , Beijing , PR China
| | - Wenwen Xin
- b State Key Laboratory of Pathogen and Biosecurity , Institute of Microbiology and Epidemiology , Beijing , PR China
| | - Baohua Zhao
- a Life Science Institute of Hebei Normal University , Shijiazhuang, Hebei Province , PR China
| | - Jinglin Wang
- b State Key Laboratory of Pathogen and Biosecurity , Institute of Microbiology and Epidemiology , Beijing , PR China
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Alves GG, Machado-de-Ávila RA, Chávez-Olórtegui CD, Silva ROS, Lobato FCF. Mapping of the continuous epitopes displayed on the Clostridium perfringens type D epsilon-toxin. Braz J Microbiol 2017; 48:570-575. [PMID: 28223027 PMCID: PMC5498415 DOI: 10.1016/j.bjm.2016.10.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Revised: 06/01/2016] [Accepted: 10/17/2016] [Indexed: 11/24/2022] Open
Abstract
The epsilon toxin, produced by Clostridium perfringens, is responsible for enterotoxemia in ruminants and is a potential bioterrorism agent. In the present study, 15 regions of the toxin were recognized by antibodies present in the serum, with different immunodominance scales, and may be antigen determinants that can be used to formulate subunit vaccines.
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Affiliation(s)
- Guilherme Guerra Alves
- Universidade Federal de Minas Gerais (UFMG), Escola de Veterinária, Belo Horizonte, MG, Brazil.
| | - Ricardo Andrez Machado-de-Ávila
- Universidade Federal de Minas Gerais (UFMG), Instituto de Ciências Biológicas, Belo Horizonte, MG, Brazil; Universidade do Extremo Sul Catarinense (UNESC), Criciúma, SC, Brazil
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25
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Structural pierce into molecular mechanism underlying Clostridium perfringens Epsilon toxin function. Toxicon 2017; 127:90-99. [PMID: 28089770 DOI: 10.1016/j.toxicon.2017.01.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 01/09/2017] [Accepted: 01/10/2017] [Indexed: 12/17/2022]
Abstract
Epsilon toxin of the Clostridium perfringens garnered a lot of attention due to its potential for toxicity in humans, extreme potency for cytotoxicity in mice and lack of any approved therapeutics prescribed for human. However, the intricacies of the Epsilon toxin action mechanism are yet to be understood. In this regard, various in silico tools have been exploited to model and refine the 3D structure of the toxin and its two receptors. The receptor proteins were embedded into designed lipid membranes within an aqueous and ionized environment. Thereafter, the modeled structures subjected to series of consecutive molecular dynamics runs to achieve the most natural like coordination for each model. Ultimately, protein-protein interaction analyses were performed to understand the probable action mechanism. The obtained results successfully confirmed the accuracy of employed methods to achieve high quality models for the toxin and its receptors within their lipid bilayers. Molecular dynamics analyses lead the structures to a more native like coordination. Moreover, the results of previous empirical studies were confirmed, while new insights for action mechanisms including the detailed roles of Hepatitis A virus cellular receptor 1 (HAVCR1) and Myelin and lymphocyte protein (MAL) proteins were achieved. In light of previous and our observations, we suggested novel models which elucidated the existing interplay between potential players of Epsilon toxin action mechanism with detailed structural evidences. These models would pave the way to have more robust understanding of the Epsilon toxin biology, more precise vaccine construction and more successful drug (inhibitor) design.
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26
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Moar WJ, Evans AJ, Kessenich CR, Baum JA, Bowen DJ, Edrington TC, Haas JA, Kouadio JLK, Roberts JK, Silvanovich A, Yin Y, Weiner BE, Glenn KC, Odegaard ML. The sequence, structural, and functional diversity within a protein family and implications for specificity and safety: The case for ETX_MTX2 insecticidal proteins. J Invertebr Pathol 2017; 142:50-59. [DOI: 10.1016/j.jip.2016.05.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 05/20/2016] [Accepted: 05/24/2016] [Indexed: 11/26/2022]
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27
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Ferreira MRA, Moreira GMSG, Cunha CEPD, Mendonça M, Salvarani FM, Moreira ÂN, Conceição FR. Recombinant Alpha, Beta, and Epsilon Toxins of Clostridium perfringens: Production Strategies and Applications as Veterinary Vaccines. Toxins (Basel) 2016; 8:E340. [PMID: 27879630 PMCID: PMC5127136 DOI: 10.3390/toxins8110340] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 11/10/2016] [Accepted: 11/14/2016] [Indexed: 01/21/2023] Open
Abstract
Clostridium perfringens is a spore-forming, commensal, ubiquitous bacterium that is present in the gastrointestinal tract of healthy humans and animals. This bacterium produces up to 18 toxins. The species is classified into five toxinotypes (A-E) according to the toxins that the bacterium produces: alpha, beta, epsilon, or iota. Each of these toxinotypes is associated with myriad different, frequently fatal, illnesses that affect a range of farm animals and humans. Alpha, beta, and epsilon toxins are the main causes of disease. Vaccinations that generate neutralizing antibodies are the most common prophylactic measures that are currently in use. These vaccines consist of toxoids that are obtained from C. perfringens cultures. Recombinant vaccines offer several advantages over conventional toxoids, especially in terms of the production process. As such, they are steadily gaining ground as a promising vaccination solution. This review discusses the main strategies that are currently used to produce recombinant vaccines containing alpha, beta, and epsilon toxins of C. perfringens, as well as the potential application of these molecules as vaccines for mammalian livestock animals.
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Affiliation(s)
- Marcos Roberto A Ferreira
- Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas, Pelotas CEP 96160-000, Rio Grande do Sul, Brazil.
| | - Gustavo Marçal S G Moreira
- Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas, Pelotas CEP 96160-000, Rio Grande do Sul, Brazil.
| | - Carlos Eduardo P da Cunha
- Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas, Pelotas CEP 96160-000, Rio Grande do Sul, Brazil.
| | - Marcelo Mendonça
- Curso de Medicina Veterinária, Unidade Acadêmica de Garanhuns, Universidade Federal Rural de Pernambuco, Garanhuns CEP 55292-270, Pernambuco, Brazil.
| | - Felipe M Salvarani
- Instituto de Medicina Veterinária, Universidade Federal do Pará, Castanhal CEP 68740-970, Pará, Brazil.
| | - Ângela N Moreira
- Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas, Pelotas CEP 96160-000, Rio Grande do Sul, Brazil.
- Faculdade de Nutrição, Universidade Federal de Pelotas, Pelotas CEP 96010-610, Rio Grande do Sul, Brazil.
| | - Fabricio R Conceição
- Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas, Pelotas CEP 96160-000, Rio Grande do Sul, Brazil.
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Takagishi T, Oda M, Takehara M, Kobayashi K, Nagahama M. Oligomer formation of Clostridium perfringens epsilon-toxin is induced by activation of neutral sphingomyelinase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:2681-2688. [PMID: 27453200 DOI: 10.1016/j.bbamem.2016.07.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Revised: 07/14/2016] [Accepted: 07/19/2016] [Indexed: 11/24/2022]
Abstract
BACKGROUND Clostridium perfringens epsilon-toxin is responsible for fatal enterotoxemia in ungulates. The toxin forms a heptamer in the lipid rafts of Madin-Darby Canine Kidney (MDCK) cells, leading to cell death. Here, we showed that epsilon-toxin requires neutral sphingomyelinase (nSMase) activity during oligomerization. METHODS We tested the role of nSMase in the oligomerization of epsilon-toxin using specific inhibitors, knockdown of nSMase, formation of ceramide, and localization of epsilon-toxin and ceramide by immunofluorescence staining. RESULTS Epsilon-toxin induced the production of ceramide is a dose- and time-dependent manner in ACHN cells. GW4869, an inhibitor of nSMase, inhibited ceramide production induced by the toxin. GW4869 and knockdown of nSMase blocked toxin-induced cell death and oligomer formation of epsilon-toxin. Confocal microscopy images showed that the toxin induced ceramide clustering and colocalized with ceramide. CONCLUSIONS These results demonstrated that oligomer formation of epsilon-toxin is facilitated by the production of ceramide through activation of nSMase caused by the toxin. GENERAL SIGNIFICANCE Inhibitors of nSMase may confer protection against infection.
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Affiliation(s)
- Teruhisa Takagishi
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho 180, Tokushima 770-8514, Japan
| | - Masataka Oda
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, 2-5274, Gakkocho-dori, Chuo-ku, Niigata 951-8514, Japan
| | - Masaya Takehara
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho 180, Tokushima 770-8514, Japan
| | - Keiko Kobayashi
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho 180, Tokushima 770-8514, Japan
| | - Masahiro Nagahama
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho 180, Tokushima 770-8514, Japan.
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Immunization with a novel Clostridium perfringens epsilon toxin mutant rETX(Y196E)-C confers strong protection in mice. Sci Rep 2016; 6:24162. [PMID: 27048879 PMCID: PMC4822168 DOI: 10.1038/srep24162] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 03/21/2016] [Indexed: 11/08/2022] Open
Abstract
Epsilon toxin (ETX) is produced by toxinotypes B and D of Clostridium perfringens. It can induce lethal enterotoxemia in domestic animals, mainly in sheep, goats and cattle, causing serious economic losses to global animal husbandry. In this study, a novel and stable epsilon toxin mutant rETXY196E-C, obtained by substituting the 196th tyrosine (Y196) with glutamic acid (E) and introducing of 23 amino acids long C-terminal peptide, was determined as a promising recombinant vaccine candidate against enterotoxemia. After the third vaccination, the antibody titers against recombinant wild type (rETX) could reach 1:105 in each immunized group, and the mice were completely protected from 100 × LD50 (50% lethal dose) of rETX challenge. The mice in 15 μg subcutaneously immunized group fully survived at the dose of 500 × LD50 of rETX challenge and 80% of mice survived at 180 μg (1000 × LD50) of rETX administration. In vitro, immune sera from 15 μg subcutaneously immunized group could completely protect MDCK cells from 16 × CT50 (50% lethal dose of cells) of rETX challenge and protect against 10 × LD50 dose (1.8 μg) of rETX challenge in mice. These data suggest that recombinant protein rETXY196E-C is a potential vaccine candidate for future applied researches.
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30
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Jerga A, Chen D, Zhang C, Fu J, Kouadio JLK, Wang Y, Duff SMG, Howard JE, Rydel TJ, Evdokimov AG, Ramaseshadri P, Evans A, Bolognesi R, Park Y, Haas JA. Mechanistic insights into the first Lygus-active β-pore forming protein. Arch Biochem Biophys 2016; 600:1-11. [PMID: 27001423 DOI: 10.1016/j.abb.2016.03.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 03/15/2016] [Accepted: 03/17/2016] [Indexed: 11/26/2022]
Abstract
The cotton pests Lygus hesperus and Lygus lineolaris can be controlled by expressing Cry51Aa2.834_16 in cotton. Insecticidal activity of pore-forming proteins is generally associated with damage to the midgut epithelium due to pores, and their biological specificity results from a set of key determinants including proteolytic activation and receptor binding. We conducted mechanistic studies to gain insight into how the first Lygus-active β-pore forming protein variant functions. Biophysical characterization revealed that the full-length Cry51Aa2.834_16 was a stable dimer in solution, and when exposed to Lygus saliva or to trypsin, the protein underwent proteolytic cleavage at the C-terminus of each of the subunits, resulting in dissociation of the dimer to two separate monomers. The monomer showed tight binding to a specific protein in Lygus brush border membranes, and also formed a membrane-associated oligomeric complex both in vitro and in vivo. Chemically cross-linking the β-hairpin to the Cry51Aa2.834_16 body rendered the protein inactive, but still competent to compete for binding sites with the native protein in vivo. Our study suggests that disassociation of the Cry51Aa2.834_16 dimer into monomeric units with unoccupied head-region and sterically unhindered β-hairpin is required for brush border membrane binding, oligomerization, and the subsequent steps leading to insect mortality.
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Affiliation(s)
| | | | | | - Jinping Fu
- Department of Entomology, Kansas State University, Manhattan, KS, USA
| | | | | | | | | | | | | | | | | | | | - Yoonseong Park
- Department of Entomology, Kansas State University, Manhattan, KS, USA
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Peraro MD, van der Goot FG. Pore-forming toxins: ancient, but never really out of fashion. Nat Rev Microbiol 2015; 14:77-92. [DOI: 10.1038/nrmicro.2015.3] [Citation(s) in RCA: 476] [Impact Index Per Article: 52.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Gil C, Dorca-Arévalo J, Blasi J. Clostridium Perfringens Epsilon Toxin Binds to Membrane Lipids and Its Cytotoxic Action Depends on Sulfatide. PLoS One 2015; 10:e0140321. [PMID: 26452234 PMCID: PMC4599917 DOI: 10.1371/journal.pone.0140321] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 09/24/2015] [Indexed: 12/23/2022] Open
Abstract
Epsilon toxin (Etx) is one of the major lethal toxins produced by Clostridium perfringens types B and D, being the causal agent of fatal enterotoxemia in animals, mainly sheep and goats. Etx is synthesized as a non-active prototoxin form (proEtx) that becomes active upon proteolytic activation. Etx exhibits a cytotoxic effect through the formation of a pore in the plasma membrane of selected cell targets where Etx specifically binds due to the presence of specific receptors. However, the identity and nature of host receptors of Etx remain a matter of controversy. In the present study, the interactions between Etx and membrane lipids from the synaptosome-enriched fraction from rat brain (P2 fraction) and MDCK cell plasma membrane preparations were analyzed. Our findings show that both Etx and proEtx bind to lipids extracted from lipid rafts from the two different models as assessed by protein-lipid overlay assay. Lipid rafts are membrane microdomains enriched in cholesterol and sphingolipids. Binding of proEtx to sulfatide, phosphatidylserine, phosphatidylinositol (3)-phosphate and phosphatidylinositol (5)-phosphate was detected. Removal of the sulphate groups via sulfatase treatment led to a dramatic decrease in Etx-induced cytotoxicity, but not in proEtx-GFP binding to MDCK cells or a significant shift in oligomer formation, pointing to a role of sulfatide in pore formation in rafts but not in toxin binding to the target cell membrane. These results show for the first time the interaction between Etx and membrane lipids from host tissue and point to a major role for sulfatides in C. perfringens epsilon toxin pathophysiology.
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Affiliation(s)
- Carles Gil
- Departament de Bioquímica i Biologia Molecular and Institut de Neurociències, Universitat Autònoma de Barcelona, Bellaterra, Catalunya, Spain
- * E-mail: (JB); (CG)
| | - Jonatan Dorca-Arévalo
- Laboratory of Cellular and Molecular Neuroscience, Department of Pathology and Experimental Therapeutics, School of Medicine, Universitat de Barcelona, L’Hospitalet de Llobregat, Barcelona, Spain
- IDIBELL-Bellvitge Biomedical Research Institute, L’Hospitalet de Llobregat, Barcelona, Spain
| | - Juan Blasi
- Laboratory of Cellular and Molecular Neuroscience, Department of Pathology and Experimental Therapeutics, School of Medicine, Universitat de Barcelona, L’Hospitalet de Llobregat, Barcelona, Spain
- IDIBELL-Bellvitge Biomedical Research Institute, L’Hospitalet de Llobregat, Barcelona, Spain
- * E-mail: (JB); (CG)
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Pore-forming activity of clostridial binary toxins. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1858:512-25. [PMID: 26278641 DOI: 10.1016/j.bbamem.2015.08.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 07/13/2015] [Accepted: 08/11/2015] [Indexed: 11/24/2022]
Abstract
Clostridial binary toxins (Clostridium perfringens Iota toxin, Clostridium difficile transferase, Clostridium spiroforme toxin, Clostridium botulinum C2 toxin) as Bacillus binary toxins, including Bacillus anthracis toxins consist of two independent proteins, one being the binding component which mediates the internalization into cell of the intracellularly active component. Clostridial binary toxins induce actin cytoskeleton disorganization through mono-ADP-ribosylation of globular actin and are responsible for enteric diseases. Clostridial and Bacillus binary toxins share structurally and functionally related binding components which recognize specific cell receptors, oligomerize, form pores in endocytic vesicle membrane, and mediate the transport of the enzymatic component into the cytosol. Binding components retain the global structure of pore-forming toxins (PFTs) from the cholesterol-dependent cytotoxin family such as perfringolysin. However, their pore-forming activity notably that of clostridial binding components is more related to that of heptameric PFT family including aerolysin and C. perfringens epsilon toxin. This review focuses upon pore-forming activity of clostridial binary toxins compared to other related PFTs. This article is part of a Special Issue entitled: Pore-Forming Toxins edited by Mauro Dalla Serra and Franco Gambale.
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Yao W, Kang L, Gao S, Zhuang X, Zhang T, Yang H, Ji B, Xin W, Wang J. Amino acid residue Y196E substitution and C-terminal peptide synergistically alleviate the toxicity of Clostridium perfringens epsilon toxin. Toxicon 2015; 100:46-52. [DOI: 10.1016/j.toxicon.2015.04.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 04/02/2015] [Accepted: 04/21/2015] [Indexed: 12/18/2022]
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Rumah KR, Ma Y, Linden JR, Oo ML, Anrather J, Schaeren-Wiemers N, Alonso MA, Fischetti VA, McClain MS, Vartanian T. The Myelin and Lymphocyte Protein MAL Is Required for Binding and Activity of Clostridium perfringens ε-Toxin. PLoS Pathog 2015; 11:e1004896. [PMID: 25993478 PMCID: PMC4439126 DOI: 10.1371/journal.ppat.1004896] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Accepted: 04/19/2015] [Indexed: 12/18/2022] Open
Abstract
Clostridium perfringens ε-toxin (ETX) is a potent pore-forming toxin responsible for a central nervous system (CNS) disease in ruminant animals with characteristics of blood-brain barrier (BBB) dysfunction and white matter injury. ETX has been proposed as a potential causative agent for Multiple Sclerosis (MS), a human disease that begins with BBB breakdown and injury to myelin forming cells of the CNS. The receptor for ETX is unknown. Here we show that both binding of ETX to mammalian cells and cytotoxicity requires the tetraspan proteolipid Myelin and Lymphocyte protein (MAL). While native Chinese Hamster Ovary (CHO) cells are resistant to ETX, exogenous expression of MAL in CHO cells confers both ETX binding and susceptibility to ETX-mediated cell death. Cells expressing rat MAL are ~100 times more sensitive to ETX than cells expressing similar levels of human MAL. Insertion of the FLAG sequence into the second extracellular loop of MAL abolishes ETX binding and cytotoxicity. ETX is known to bind specifically and with high affinity to intestinal epithelium, renal tubules, brain endothelial cells and myelin. We identify specific binding of ETX to these structures and additionally show binding to retinal microvasculature and the squamous epithelial cells of the sclera in wild-type mice. In contrast, there is a complete absence of ETX binding to tissues from MAL knockout (MAL-/-) mice. Furthermore, MAL-/- mice exhibit complete resistance to ETX at doses in excess of 1000 times the symptomatic dose for wild-type mice. We conclude that MAL is required for both ETX binding and cytotoxicity.
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Affiliation(s)
- Kareem Rashid Rumah
- Brain and Mind Research Institute, Weill Cornell Medical College, New York City, New York, United States of America
- Laboratory of Bacterial Pathogenesis and Immunology, The Rockefeller University, New York City, New York, United States of America
| | - Yinghua Ma
- Brain and Mind Research Institute, Weill Cornell Medical College, New York City, New York, United States of America
| | - Jennifer R. Linden
- Brain and Mind Research Institute, Weill Cornell Medical College, New York City, New York, United States of America
| | - Myat Lin Oo
- Brain and Mind Research Institute, Weill Cornell Medical College, New York City, New York, United States of America
| | - Josef Anrather
- Brain and Mind Research Institute, Weill Cornell Medical College, New York City, New York, United States of America
| | - Nicole Schaeren-Wiemers
- Neurobiology, Department of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Miguel A. Alonso
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Cantoblanco, Madrid, Spain
| | - Vincent A. Fischetti
- Laboratory of Bacterial Pathogenesis and Immunology, The Rockefeller University, New York City, New York, United States of America
| | - Mark S. McClain
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Timothy Vartanian
- Brain and Mind Research Institute, Weill Cornell Medical College, New York City, New York, United States of America
- * E-mail:
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Identification of tyrosine 71 as a critical residue for the cytotoxic activity of Clostridium perfringens epsilon toxin towards MDCK cells. J Microbiol 2015; 53:141-6. [PMID: 25626370 DOI: 10.1007/s12275-015-4523-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 11/24/2014] [Accepted: 12/11/2014] [Indexed: 01/18/2023]
Abstract
Clostridium perfringens epsilon toxin (Etx) is an extremely potent toxin, causing fatal enterotoxaemia in many animals. Several amino acids in domains I and II have been proposed to be critical for Etx to interact with MDCK cells. However, the critical amino acids in domain III remain undefined. Therefore, we assessed the effects of aromatic amino acids in domain III on Etx activity in this study. All of the results indicated that Y71 was critical for the cytotoxic activity of Etx towards MDCK cells, and this activity was dependent on the existence of an aromatic ring residue in position 71. Additionally, mutations in Y71 did not affect the binding of Etx to MDCK cells, indicating that Y71 is not a receptor binding site for Etx. In summary, we identified an amino acid in domain III that is important for the cytotoxic activity of Etx, thereby providing information on the structure-function relationship of Etx.
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Clostridial pore-forming toxins: Powerful virulence factors. Anaerobe 2014; 30:220-38. [DOI: 10.1016/j.anaerobe.2014.05.014] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 04/16/2014] [Accepted: 05/25/2014] [Indexed: 01/05/2023]
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Alves GG, Machado de Ávila RA, Chávez-Olórtegui CD, Lobato FCF. Clostridium perfringens epsilon toxin: the third most potent bacterial toxin known. Anaerobe 2014; 30:102-7. [PMID: 25234332 DOI: 10.1016/j.anaerobe.2014.08.016] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 08/18/2014] [Accepted: 08/19/2014] [Indexed: 01/24/2023]
Abstract
Epsilon toxin (ETX) is produced by Clostridium perfringens type B and D strains and causes enterotoxemia, a highly lethal disease with major impacts on the farming of domestic ruminants, particularly sheep. ETX belongs to the aerolysin-like pore-forming toxin family. Although ETX has striking similarities to other toxins in this family, ETX is often more potent, with an LD50 of 100 ng/kg in mice. Due to this high potency, ETX is considered as a potential bioterrorism agent and has been classified as a category B biological agent by the Centers for Disease Control and Prevention (CDC) of the United States. The protoxin is converted to an active toxin through proteolytic cleavage performed by specific proteases. ETX is absorbed and acts locally in the intestines then subsequently binds to and causes lesions in other organs, including the kidneys, lungs and brain. The importance of this toxin for veterinary medicine and its possible use as a biological weapon have drawn the attention of researchers and have led to a large number of studies investigating ETX. The aim of the present work is to review the existing knowledge on ETX from C. perfringens type B and D.
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Affiliation(s)
- Guilherme Guerra Alves
- Veterinary School, Universidade Federal de Minas Gerais (UFMG), Antônio Carlos Avenue, 6627, Belo Horizonte, MG CEP 31.270-901, Brazil.
| | | | - Carlos Delfin Chávez-Olórtegui
- Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Antônio Carlos Avenue, 6627, Belo Horizonte, MG CEP 31.270-901, Brazil
| | - Francisco Carlos Faria Lobato
- Veterinary School, Universidade Federal de Minas Gerais (UFMG), Antônio Carlos Avenue, 6627, Belo Horizonte, MG CEP 31.270-901, Brazil.
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Abstract
In both humans and animals, Clostridium perfringens is an important cause of histotoxic infections and diseases originating in the intestines, such as enteritis and enterotoxemia. The virulence of this Gram-positive, anaerobic bacterium is heavily dependent upon its prolific toxin-producing ability. Many of the ∼16 toxins produced by C. perfringens are encoded by large plasmids that range in size from ∼45 kb to ∼140 kb. These plasmid-encoded toxins are often closely associated with mobile elements. A C. perfringens strain can carry up to three different toxin plasmids, with a single plasmid carrying up to three distinct toxin genes. Molecular Koch's postulate analyses have established the importance of several plasmid-encoded toxins when C. perfringens disease strains cause enteritis or enterotoxemias. Many toxin plasmids are closely related, suggesting a common evolutionary origin. In particular, most toxin plasmids and some antibiotic resistance plasmids of C. perfringens share an ∼35-kb region containing a Tn916-related conjugation locus named tcp (transfer of clostridial plasmids). This tcp locus can mediate highly efficient conjugative transfer of these toxin or resistance plasmids. For example, conjugative transfer of a toxin plasmid from an infecting strain to C. perfringens normal intestinal flora strains may help to amplify and prolong an infection. Therefore, the presence of toxin genes on conjugative plasmids, particularly in association with insertion sequences that may mobilize these toxin genes, likely provides C. perfringens with considerable virulence plasticity and adaptability when it causes diseases originating in the gastrointestinal tract.
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Bokori-Brown M, Hall CA, Vance C, Fernandes da Costa SP, Savva CG, Naylor CE, Cole AR, Basak AK, Moss DS, Titball RW. Clostridium perfringens epsilon toxin mutant Y30A-Y196A as a recombinant vaccine candidate against enterotoxemia. Vaccine 2014; 32:2682-7. [PMID: 24709588 PMCID: PMC4022833 DOI: 10.1016/j.vaccine.2014.03.079] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 03/11/2014] [Accepted: 03/25/2014] [Indexed: 12/17/2022]
Abstract
Etx mutant Y30A-Y196A showed markedly reduced cytotoxicity towards MDCK.2 cells. Y30A-Y196A is inactive in mice after intraperitoneal administration. Y30A-Y196A is able to induce a specific antibody response in rabbits. Y30A-Y196A polyclonal antibody is able to induce protective immunity in vitro. Y30A-Y196A could form the basis of a recombinant vaccine against enterotoxemia.
Epsilon toxin (Etx) is a β-pore-forming toxin produced by Clostridium perfringens toxinotypes B and D and plays a key role in the pathogenesis of enterotoxemia, a severe, often fatal disease of ruminants that causes significant economic losses to the farming industry worldwide. This study aimed to determine the potential of a site-directed mutant of Etx (Y30A-Y196A) to be exploited as a recombinant vaccine against enterotoxemia. Replacement of Y30 and Y196 with alanine generated a stable variant of Etx with significantly reduced cell binding and cytotoxic activities in MDCK.2 cells relative to wild type toxin (>430-fold increase in CT50) and Y30A-Y196A was inactive in mice after intraperitoneal administration of trypsin activated toxin at 1000× the expected LD50 dose of trypsin activated wild type toxin. Moreover, polyclonal antibody raised in rabbits against Y30A-Y196A provided protection against wild type toxin in an in vitro neutralisation assay. These data suggest that Y30A-Y196A mutant could form the basis of an improved recombinant vaccine against enterotoxemia.
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Affiliation(s)
- Monika Bokori-Brown
- College of Life and Environmental Sciences, University of Exeter, Stocker Road, Exeter EX4 4QD, United Kingdom.
| | - Charlotte A Hall
- College of Life and Environmental Sciences, University of Exeter, Stocker Road, Exeter EX4 4QD, United Kingdom
| | - Charlotte Vance
- College of Life and Environmental Sciences, University of Exeter, Stocker Road, Exeter EX4 4QD, United Kingdom
| | - Sérgio P Fernandes da Costa
- College of Life and Environmental Sciences, University of Exeter, Stocker Road, Exeter EX4 4QD, United Kingdom
| | - Christos G Savva
- Department of Biological Sciences, Birkbeck College, Malet Street, London WC1E 7HX, United Kingdom
| | - Claire E Naylor
- Department of Biological Sciences, Birkbeck College, Malet Street, London WC1E 7HX, United Kingdom
| | - Ambrose R Cole
- Department of Biological Sciences, Birkbeck College, Malet Street, London WC1E 7HX, United Kingdom
| | - Ajit K Basak
- Department of Biological Sciences, Birkbeck College, Malet Street, London WC1E 7HX, United Kingdom
| | - David S Moss
- Department of Biological Sciences, Birkbeck College, Malet Street, London WC1E 7HX, United Kingdom
| | - Richard W Titball
- College of Life and Environmental Sciences, University of Exeter, Stocker Road, Exeter EX4 4QD, United Kingdom
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Chen J, Ma M, Uzal FA, McClane BA. Host cell-induced signaling causes Clostridium perfringens to upregulate production of toxins important for intestinal infections. Gut Microbes 2014; 5:96-107. [PMID: 24061146 PMCID: PMC4049945 DOI: 10.4161/gmic.26419] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Clostridium perfringens causes enteritis and enterotoxemia in humans and livestock due to prolific toxin production. In broth culture, C. perfringens uses the Agr-like quorum sensing (QS) system to regulate production of toxins important for enteritis/enterotoxemia, including beta toxin (CPB), enterotoxin, and epsilon toxin (ETX). The VirS/VirR two-component regulatory system (TCRS) also controls CPB production in broth cultures. Both the Agr-like QS and VirS/VirR systems are important when C. perfringens senses enterocyte-like Caco-2 cells and responds by upregulating CPB production; however, only the Agr-like QS system is needed for host cell-induced ETX production. These in vitro observations have pathophysiologic relevance since both the VirS/VirR and Agr-like QS signaling systems are required for C. perfringens strain CN3685 to produce CPB in vivo and to cause enteritis or enterotoxemia. Thus, apparently upon sensing its presence in the intestines, C. perfringens utilizes QS and TCRS signaling to produce toxins necessary for intestinal virulence.
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Affiliation(s)
- Jianming Chen
- Department of Microbiology and Molecular Genetics; University of Pittsburgh School of Medicine; Pittsburgh, PA USA
| | - Menglin Ma
- Department of Microbiology and Molecular Genetics; University of Pittsburgh School of Medicine; Pittsburgh, PA USA
| | - Francisco A Uzal
- California Animal Health and Food Safety Laboratory; San Bernadino Branch, School of Veterinary Medicine; University of California Davis; San Bernadino, CA USA
| | - Bruce A McClane
- Department of Microbiology and Molecular Genetics; University of Pittsburgh School of Medicine; Pittsburgh, PA USA,Correspondence to: Bruce A McClane,
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Clostridium perfringens epsilon toxin: a malevolent molecule for animals and man? Toxins (Basel) 2013; 5:2138-60. [PMID: 24284826 PMCID: PMC3847718 DOI: 10.3390/toxins5112138] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 10/30/2013] [Accepted: 10/31/2013] [Indexed: 12/27/2022] Open
Abstract
Clostridium perfringens is a prolific, toxin-producing anaerobe causing multiple diseases in humans and animals. One of these toxins is epsilon, a 33 kDa protein produced by Clostridium perfringens (types B and D) that induces fatal enteric disease of goats, sheep and cattle. Epsilon toxin (Etx) belongs to the aerolysin-like toxin family. It contains three distinct domains, is proteolytically-activated and forms oligomeric pores on cell surfaces via a lipid raft-associated protein(s). Vaccination controls Etx-induced disease in the field. However, therapeutic measures are currently lacking. This review initially introduces C. perfringens toxins, subsequently focusing upon the Etx and its biochemistry, disease characteristics in various animals that include laboratory models (in vitro and in vivo), and finally control mechanisms (vaccines and therapeutics).
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Li Q, Xin W, Gao S, Kang L, Wang J. A low-toxic site-directed mutant of Clostridium perfringens ε-toxin as a potential candidate vaccine against enterotoxemia. Hum Vaccin Immunother 2013; 9:2386-92. [PMID: 23835363 DOI: 10.4161/hv.25649] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Clostridium perfringens epsilon toxin (ETX), one of the most potent toxins known, is a potential biological weapon; therefore, the development of an effective vaccine is important for preventing intoxication or disease by ETX. In this study, genetically detoxified epsilon toxin mutants were developed as candidate vaccines. We used site-directed mutagenesis to mutate the essential amino acid residues (His106, Ser111 and Phe199). Six site-directed mutants of ETX (mETX (H106P) , mETX (S111H) , mETX (S111Y) , mETX (F199H) , mETX (F199E) , mETX (S111YF199E) ) were generated and then expressed in Escherichia coli. Both mETX (F199E) and mETX (H106P) with low or non-cytotoxicity that retained their immunogenicity were selected to immunize mice 3 times, and the mouse survival data were recorded after challenging with recombinant wild-type ETX. mETX (F199E) induces the same protection as mETX (H106P) , which was reported previously as a promising toxin mutant for vaccine, and both of them could protect immunized mice against a 100× LD₅₀ dose of active wild-type recombinant ETX. This work showed that mETX (F199E) is another promising candidate vaccine against enterotoxemia and other diseases caused by ETX.
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Affiliation(s)
- Qing Li
- Anhui Medical University; Hefei, Anhui, PR China; State Key Laboratory of Pathogen and Biosecurity; Institute of Microbiology and Epidemiology; Academy of Military Medical Sciences; Beijing, PR China
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Wioland L, Dupont JL, Bossu JL, Popoff MR, Poulain B. Attack of the nervous system by Clostridium perfringens Epsilon toxin: from disease to mode of action on neural cells. Toxicon 2013; 75:122-35. [PMID: 23632158 DOI: 10.1016/j.toxicon.2013.04.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Revised: 03/29/2013] [Accepted: 04/10/2013] [Indexed: 12/24/2022]
Abstract
Epsilon toxin (ET), produced by Clostridium perfringens types B and D, ranks among the four most potent poisonous substances known so far. ET-intoxication is responsible for enterotoxaemia in animals, mainly sheep and goats. This disease comprises several manifestations indicating the attack of the nervous system. This review aims to summarize the effects of ET on central nervous system. ET binds to endothelial cells of brain capillary vessels before passing through the blood-brain barrier. Therefore, it induces perivascular oedema and accumulates into brain. ET binding to different brain structures and to different component in the brain indicates regional susceptibility to the toxin. Histological examination has revealed nerve tissue and cellular lesions, which may be directly or indirectly caused by ET. The naturally occurring disease caused by ET-intoxication can be reproduced experimentally in rodents. In mice and rats, ET recognizes receptor at the surface of different neural cell types, including certain neurons (e.g. the granule cells in cerebellum) as well as oligodendrocytes, which are the glial cells responsible for the axons myelination. Moreover, ET induces release of glutamate and other transmitters, leading to firing of neural network. The precise mode of action of ET on neural cells remains to be determined.
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Affiliation(s)
- Laetitia Wioland
- Centre National de la Recherche Scientifique (CNRS) and Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives (INCI), UPR 3212, Strasbourg, France
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Bokori-Brown M, Kokkinidou MC, Savva CG, Fernandes da Costa S, Naylor CE, Cole AR, Moss DS, Basak AK, Titball RW. Clostridium perfringens epsilon toxin H149A mutant as a platform for receptor binding studies. Protein Sci 2013; 22:650-9. [PMID: 23504825 PMCID: PMC3649266 DOI: 10.1002/pro.2250] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 03/08/2013] [Indexed: 12/24/2022]
Abstract
Clostridium perfringens epsilon toxin (Etx) is a pore-forming toxin responsible for a severe and rapidly fatal enterotoxemia of ruminants. The toxin is classified as a category B bioterrorism agent by the U.S. Government Centres for Disease Control and Prevention (CDC), making work with recombinant toxin difficult. To reduce the hazard posed by work with recombinant Etx, we have used a variant of Etx that contains a H149A mutation (Etx-H149A), previously reported to have reduced, but not abolished, toxicity. The three-dimensional structure of H149A prototoxin shows that the H149A mutation in domain III does not affect organisation of the putative receptor binding loops in domain I of the toxin. Surface exposed tyrosine residues in domain I of Etx-H149A (Y16, Y20, Y29, Y30, Y36 and Y196) were mutated to alanine and mutants Y30A and Y196A showed significantly reduced binding to MDCK.2 cells relative to Etx-H149A that correlated with their reduced cytotoxic activity. Thus, our study confirms the role of surface exposed tyrosine residues in domain I of Etx in binding to MDCK cells and the suitability of Etx-H149A for further receptor binding studies. In contrast, binding of all of the tyrosine mutants to ACHN cells was similar to that of Etx-H149A, suggesting that Etx can recognise different cell surface receptors. In support of this, the crystal structure of Etx-H149A identified a glycan (β-octyl-glucoside) binding site in domain III of Etx-H149A, which may be a second receptor binding site. These findings have important implications for developing strategies designed to neutralise toxin activity.
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Affiliation(s)
- Monika Bokori-Brown
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, United Kingdom.
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