1
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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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2
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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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3
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Du J, Meki I, Li Q, Liu Y, Zhu Z, Pan C, Xia Y, Fu L, Yang L, Zhang S, Yin C, Luo Y, Wang T, Liu B, Chen X. A non-toxic recombinant Clostridium septicum α toxin induces protective immunity in mice and rabbits. Toxicon 2023; 233:107234. [PMID: 37543293 DOI: 10.1016/j.toxicon.2023.107234] [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: 04/10/2023] [Revised: 07/31/2023] [Accepted: 08/01/2023] [Indexed: 08/07/2023]
Abstract
Clostridium septicum alpha toxin (CSA) plays significant roles in ruminant's braxy. Genetically engineered CSA has been shown to function as a potential vaccine candidate in the prevention of the disease caused by Clostridium septicum. In the present study, we synthesized a non-toxic recombinant, rCSAm4/TMD by introducing four amino acid substitutions (C86L/N296A/H301A/W342A) and 11-amino-acid deletion (residues 212 to 222). Compared to recombinant CSA, rCSAm4/TMD showed no cytotoxicity to MDCK cells and was not fatal to mice. Moreover, rCSAm4/TMD could protect immunized mice against 5 × mouse LD100 (100% lethal dose) of crude CSA without obvious pathological change. Most importantly, rabbits immunized with rCSAm4/TMD produced high titers of neutralizing antibodies which protected the rabbits against crude CSA challenge. These data suggest that genetically detoxified rCSAm4/TMD is a potential subunit vaccine candidate against braxy.
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Affiliation(s)
- Jige Du
- China Institute of Veterinary Drug Control, Beijing, People's Republic of China
| | - Irene Meki
- International Atomic Energy Agency, Vienna, Austria
| | - Qianlin Li
- China Institute of Veterinary Drug Control, Beijing, People's Republic of China
| | - Ying Liu
- China Institute of Veterinary Drug Control, Beijing, People's Republic of China
| | - Zhen Zhu
- China Institute of Veterinary Drug Control, Beijing, People's Republic of China
| | - Chenfan Pan
- China Institute of Veterinary Drug Control, Beijing, People's Republic of China
| | - Yingju Xia
- China Institute of Veterinary Drug Control, Beijing, People's Republic of China
| | - Lizhi Fu
- Chongqing Academy of Animal Sciences, Chongqing, 402460, China
| | - Liu Yang
- Chongqing Academy of Animal Sciences, Chongqing, 402460, China
| | - Suhui Zhang
- Chongqing Academy of Animal Sciences, Chongqing, 402460, China
| | - Chunsheng Yin
- China Institute of Veterinary Drug Control, Beijing, People's Republic of China
| | - Yufeng Luo
- China Institute of Veterinary Drug Control, Beijing, People's Republic of China
| | - Tuanjie Wang
- China Institute of Veterinary Drug Control, Beijing, People's Republic of China.
| | - Bo Liu
- China Institute of Veterinary Drug Control, Beijing, People's Republic of China; International Atomic Energy Agency, Vienna, Austria.
| | - Xiaoyun Chen
- China Institute of Veterinary Drug Control, Beijing, People's Republic of China.
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4
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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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5
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A non-toxic recombinant bivalent chimeric protein rETX m3CSA m4/TMD as a potential vaccine candidate against enterotoxemia and braxy. Vaccine 2023; 41:1232-1238. [PMID: 36635138 DOI: 10.1016/j.vaccine.2022.11.021] [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: 06/13/2022] [Revised: 11/11/2022] [Accepted: 11/13/2022] [Indexed: 01/11/2023]
Abstract
Clostridium perfringens epsilon toxin (ETX) and Clostridium septicum alpha toxin (CSA) are lethal and necrotizing toxins, which play key roles in enterotoxemia and braxy of ruminants, respectively. In the present study, we synthesized a bivalent chimeric protein rETXm3CSAm4/TMD comprising ETXm3 (Y30A/H106P/Y196A) and CSAm4/TMD (C86L/N296A/H301A/W342A and a deletion of residues 212 to 222). Compared with recombinant ETX and recombinant CSA, rETXm3CSAm4/TMD showed no cytotoxicity in Madin-Darby Canine Kidney cells and was not fatal to mice. Moreover, rETXm3CSAm4/TMD could protect immunized mice against 10 × mouse LD100 of crude ETX or 3 × mouse LD100 of crude CSA without obvious histopathologic difference. Most importantly, both rabbits and sheep immunized with rETXm3CSAm4/TMD produced high titers of neutralizing antibody which protected the animals against the challenge with crude ETX or crude CSA. These data suggest that genetically detoxified rETXm3CSAm4/TMD is a potential subunit vaccine candidate against enterotoxemia and braxy.
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6
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Marshall S, McGill B, Morcrette H, Winlove CP, Chimerel C, Petrov PG, Bokori-Brown M. Interaction of Clostridium perfringens Epsilon Toxin with the Plasma Membrane: The Role of Amino Acids Y42, Y43 and H162. Toxins (Basel) 2022; 14:toxins14110757. [PMID: 36356007 PMCID: PMC9694948 DOI: 10.3390/toxins14110757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/17/2022] [Accepted: 10/28/2022] [Indexed: 11/06/2022] Open
Abstract
Clostridium perfringens epsilon toxin (Etx) is a pore forming toxin that causes enterotoxaemia in ruminants and may be a cause of multiple sclerosis in humans. To date, most in vitro studies of Etx have used the Madin-Darby canine kidney (MDCK) cell line. However, studies using Chinese hamster ovary (CHO) cells engineered to express the putative Etx receptor, myelin and lymphocyte protein (MAL), suggest that amino acids important for Etx activity differ between species. In this study, we investigated the role of amino acids Y42, Y43 and H162, previously identified as important in Etx activity towards MDCK cells, in Etx activity towards CHO-human MAL (CHO-hMAL) cells, human red blood cells (hRBCs) and synthetic bilayers using site-directed mutants of Etx. We show that in CHO-hMAL cells Y42 is critical for Etx binding and not Y43 as in MDCK cells, indicating that surface exposed tyrosine residues in the receptor binding domain of Etx impact efficiency of cell binding to MAL-expressing cells in a species-specific manner. We also show that Etx mutant H162A was unable to lyse CHO-hMAL cells, lysed hRBCs, whilst it was able to form pores in synthetic bilayers, providing evidence of the complexity of Etx pore formation in different lipid environments.
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Affiliation(s)
- Skye Marshall
- Department of Physics and Astronomy, University of Exeter, Stocker Road, Exeter EX4 4QL, UK
| | - Beth McGill
- Department of Physics and Astronomy, University of Exeter, Stocker Road, Exeter EX4 4QL, UK
| | - Helen Morcrette
- College of Life and Environmental Sciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - C. Peter Winlove
- Department of Physics and Astronomy, University of Exeter, Stocker Road, Exeter EX4 4QL, UK
| | - Catalin Chimerel
- Automation Department, Faculty of Electrical Engineering and Computer Science, Transilvania University of Brasov, 500036 Brasov, Romania
- Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - Peter G. Petrov
- Department of Physics and Astronomy, University of Exeter, Stocker Road, Exeter EX4 4QL, UK
- Correspondence: (P.G.P.); (M.B.-B.); Tel.: +44-1392-724139 (P.G.P.)
| | - Monika Bokori-Brown
- College of Life and Environmental Sciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
- Correspondence: (P.G.P.); (M.B.-B.); Tel.: +44-1392-724139 (P.G.P.)
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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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8
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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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9
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PENG X, LI X, PENG G, FENG L, JIANG Y, LUO Y. Recombinant unpurified rETX H106P/ CTB-rETX Y196E protects rabbits against Clostridium perfringens epsilon toxin. J Vet Med Sci 2021; 83:441-446. [PMID: 33551442 PMCID: PMC8025428 DOI: 10.1292/jvms.20-0385] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 01/19/2021] [Indexed: 11/22/2022] Open
Abstract
Epsilon toxin (ETX), produced by Clostridium perfringens types B and D, has been touted as a potential biological weapon and is known to induce fatal enterotoxemia in a variety of livestock animals. For the efficient production of recombinant proteins with the objective of investigating the effects of different recombinant vaccines against ETX, a bicistronic design (BCD) expression system including the ETX coding sequence with mutation of amino acid 106 from Histidine to Proline (ETXH106P) in the first cistron, followed by Cholera Toxin B (CTB) linked with the ETX coding sequence with mutation of amino acid 196 from Tyrosine to Glutamic acid (ETXY196E) in the second cistron, was generated under the control of a single promoter. Rabbits were immunized twice with five inactivated recombinant Escherichia coli (E. coli) vaccines containing 100 µg/ml of the recombinant mutant rETXH106P/CTB-rETXY196E proteins mixed with different adjuvants. Apart from rETXH106P/CTB-rETXY196E-IMS1313-vaccinated rabbits, the neutralizing antibody titers of rETXH106P/CTB-rETXY196E-vaccinated rabbits were higher after the initial immunization than those administered the ETX toxoid or current commercial vaccines. rETXH106P/CTB-rETXY196E mixed with ISA201 induced the highest neutralizing antibody titer of 120 after the first immunization, suggesting that 0.1 ml of pooled sera could neutralize 120× mouse LD100 (100% lethal dose) of ETX. Following the second vaccination, rETXH106P/CTB-rETXY196E mixed with ISA201 or GR208 produced the highest neutralizing titer of 800. Rabbits from all vaccinated groups were completely protected from a 2× rabbit LD100 of ETX challenge. These results show that these novel recombinant proteins can induce a strong immune response and represent potential targets for the development of a commercial vaccine against the C. perfringens epsilon toxin.
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Affiliation(s)
- Xiaobing PENG
- Department of Bacterial Biologics, China Institute of Veterinary Drug Control, No. 8 Zhongguancun South Street, Beijing 100-081,
China
| | - Xuni LI
- Department of Bacterial Biologics, China Institute of Veterinary Drug Control, No. 8 Zhongguancun South Street, Beijing 100-081,
China
| | - Guorui PENG
- Department of Bacterial Biologics, China Institute of Veterinary Drug Control, No. 8 Zhongguancun South Street, Beijing 100-081,
China
| | - Lifang FENG
- Beijing Zhonghai Biotech Co., Ltd., No. 8 Zhongguancun South Street, Beijing 100-081, China
| | - Yuwen JIANG
- Department of Bacterial Biologics, China Institute of Veterinary Drug Control, No. 8 Zhongguancun South Street, Beijing 100-081,
China
| | - Yufeng LUO
- Department of Bacterial Biologics, China Institute of Veterinary Drug Control, No. 8 Zhongguancun South Street, Beijing 100-081,
China
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10
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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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11
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Dorca-Arévalo J, Dorca E, Torrejón-Escribano B, Blanch M, Martín-Satué M, Blasi J. Lung endothelial cells are sensitive to epsilon toxin from Clostridium perfringens. Vet Res 2020; 51:27. [PMID: 32093740 PMCID: PMC7041264 DOI: 10.1186/s13567-020-00748-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 01/22/2020] [Indexed: 11/12/2022] Open
Abstract
The pore-forming protein epsilon toxin (Etx) from Clostridium perfringens produces acute perivascular edema affecting several organs, especially the brain and lungs. Despite the toxin evident effect on microvasculature and endothelial cells, the underlying molecular and cellular mechanisms remain obscure. Moreover, no Etx-sensitive endothelial cell model has been identified to date. Here, we characterize the mouse lung endothelial cell line 1G11 as an Etx-sensitive cell line and compare it with the well-characterized Etx-sensitive Madin-Darby canine kidney epithelial cell line. Several experimental approaches, including morphological and cytotoxic assays, clearly demonstrate that the 1G11 cell line is highly sensitive to Etx and show the specific binding, oligomerization, and pore-forming activity of the toxin in these cells. Recently, the myelin and lymphocyte (MAL) protein has been postulated as a putative receptor for Etx. Here, we show the presence of Mal mRNA in the 1G11 cell line and the presence of the MAL protein in the endothelium of some mouse lung vessels, supporting the hypothesis that this protein is a key element in the Etx intoxication pathway. The existence of an Etx-sensitive cell line of endothelial origin would help shed light on the cellular and molecular mechanisms underlying Etx-induced edema and its consequences.
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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, Barcelona, Spain. .,Biomedical Research Institute of Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain. .,Institute of Neurosciences, University of Barcelona, 08035, Barcelona, Spain.
| | - Eduard Dorca
- Pathology Service, Bellvitge University Hospital, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Benjamín Torrejón-Escribano
- Department of Pathology and Experimental Therapeutics, Faculty of Medicine and Health Sciences, Campus of Bellvitge, University of Barcelona, Hospitalet de Llobregat, Barcelona, Spain.,Centres Científics i Tecnològics, Universitat de Barcelona, Campus Bellvitge, Barcelona, Spain
| | - Marta Blanch
- Department of Pathology and Experimental Therapeutics, Faculty of Medicine and Health Sciences, Campus of Bellvitge, University of Barcelona, Hospitalet de Llobregat, Barcelona, Spain.,Biomedical Research Institute of Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain.,Institute of Neurosciences, University of Barcelona, 08035, Barcelona, Spain
| | - Mireia Martín-Satué
- Department of Pathology and Experimental Therapeutics, Faculty of Medicine and Health Sciences, Campus of Bellvitge, University of Barcelona, Hospitalet de Llobregat, Barcelona, Spain.,Biomedical Research Institute of Bellvitge (IDIBELL), Oncobell Program, CIBERONC, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Juan Blasi
- Department of Pathology and Experimental Therapeutics, Faculty of Medicine and Health Sciences, Campus of Bellvitge, University of Barcelona, Hospitalet de Llobregat, Barcelona, Spain.,Biomedical Research Institute of Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain.,Institute of Neurosciences, University of Barcelona, 08035, Barcelona, Spain
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12
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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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13
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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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14
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Adler D, Linden JR, Shetty SV, Ma Y, Bokori-Brown M, Titball RW, Vartanian T. Clostridium perfringens Epsilon Toxin Compromises the Blood-Brain Barrier in a Humanized Zebrafish Model. iScience 2019; 15:39-54. [PMID: 31030181 PMCID: PMC6487375 DOI: 10.1016/j.isci.2019.04.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 12/29/2018] [Accepted: 04/08/2019] [Indexed: 12/22/2022] Open
Abstract
Clostridium perfringens epsilon toxin (ETX) is hypothesized to mediate blood-brain barrier (BBB) permeability by binding to the myelin and lymphocyte protein (MAL) on the luminal surface of endothelial cells (ECs). However, the kinetics of this interaction and a general understanding of ETX's behavior in a live organism have yet to be appreciated. Here we investigate ETX binding and BBB breakdown in living Danio rerio (zebrafish). Wild-type zebrafish ECs do not bind ETX. When zebrafish ECs are engineered to express human MAL (hMAL), proETX binding occurs in a time-dependent manner. Injection of activated toxin in hMAL zebrafish initiates BBB leakage, hMAL downregulation, blood vessel stenosis, perivascular edema, and blood stasis. We propose a kinetic model of MAL-dependent ETX binding and neurovascular pathology. By generating a humanized zebrafish BBB model, this study contributes to our understanding of ETX-induced BBB permeability and strengthens the proposal that MAL is the ETX receptor.
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Affiliation(s)
- Drew Adler
- Brain and Mind Research Institute, Weill Cornell Medical College of Cornell University, New York, NY 10065, USA; Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14850, USA
| | - Jennifer R Linden
- Brain and Mind Research Institute, Weill Cornell Medical College of Cornell University, New York, NY 10065, USA
| | - Samantha V Shetty
- Brain and Mind Research Institute, Weill Cornell Medical College of Cornell University, New York, NY 10065, USA
| | - Yinghua Ma
- Brain and Mind Research Institute, Weill Cornell Medical College of Cornell University, New York, NY 10065, USA
| | | | - Richard W Titball
- Department of Biosciences, University of Exeter, Exeter, Devon EX4 4SB, UK
| | - Timothy Vartanian
- Brain and Mind Research Institute, Weill Cornell Medical College of Cornell University, New York, NY 10065, USA.
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15
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Orally administered recombinant Lactobacillus casei vector vaccine expressing β-toxoid of Clostridium perfringens that induced protective immunity responses. Res Vet Sci 2017; 115:332-339. [DOI: 10.1016/j.rvsc.2017.06.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Revised: 06/05/2017] [Accepted: 06/26/2017] [Indexed: 11/30/2022]
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16
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Cirauqui N, Abriata LA, van der Goot FG, Dal Peraro M. Structural, physicochemical and dynamic features conserved within the aerolysin pore-forming toxin family. Sci Rep 2017; 7:13932. [PMID: 29066778 PMCID: PMC5654971 DOI: 10.1038/s41598-017-13714-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 09/26/2017] [Indexed: 11/10/2022] Open
Abstract
Aerolysin is the founding member of a major class of β-pore-forming toxins (β-PFTs) found throughout all kingdoms of life. PFTs are cytotoxic proteins produced as soluble monomers, which oligomerize at the membrane of target host cells forming pores that may lead to osmotic lysis and cell death. Besides their role in microbial infection, they have become interesting for their potential as biotechnological sensors and delivery systems. Using an approach that integrates bioinformatics with molecular modeling and simulation, we looked for conserved features across this large toxin family. The cell surface-binding domains present high variability within the family to provide membrane receptor specificity. On the contrary, the novel concentric double β-barrel structure found in aerolysin is highly conserved in terms of sequence, structure and conformational dynamics, which likely contribute to preserve a common transition mechanism from the prepore to the mature pore within the family.Our results point to the key role of several amino acids in the conformational changes needed for oligomerization and further pore formation, such as Y221, W227, P248, Q263 and L277, which we propose are involved in the release of the stem loop and the two adjacent β-strands to form the transmembrane β-barrel.
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Affiliation(s)
- Nuria Cirauqui
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
- Department of Pharmaceutical Biotechnology, Universidade Federal do Rio de Janeiro, 21941-902, Rio de Janeiro, Brazil
| | - Luciano A Abriata
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - F Gisou van der Goot
- Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Matteo Dal Peraro
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.
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17
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Recombinant Lactobacillus casei expressing Clostridium perfringens toxoids α, β2, ε and β1 gives protection against Clostridium perfringens in rabbits. Vaccine 2017. [DOI: 10.1016/j.vaccine.2017.05.076] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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18
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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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19
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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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20
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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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21
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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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22
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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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23
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Oral immunization of mice against Clostridium perfringens epsilon toxin with a Lactobacillus casei vector vaccine expressing epsilon toxoid. INFECTION GENETICS AND EVOLUTION 2016; 40:282-287. [DOI: 10.1016/j.meegid.2016.03.020] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 03/15/2016] [Accepted: 03/18/2016] [Indexed: 11/24/2022]
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24
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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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Jiang Z, De Y, Chang J, Wang F, Yu L. Induction of potential protective immunity against enterotoxemia in calves by single or multiple recombinant Clostridium perfringens toxoids. Microbiol Immunol 2015; 58:621-7. [PMID: 25197030 DOI: 10.1111/1348-0421.12198] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 07/07/2014] [Accepted: 09/03/2014] [Indexed: 11/30/2022]
Abstract
Cattle enterotoxemia caused by Clostridium perfringens toxins is a noncontagious, sporadic, and fatal disease characterized by sudden death. Strategies for controlling and preventing cattle enterotoxemia are based on systematic vaccination of herds with toxoids. Because the process of producing conventional clostridial vaccines is dangerous, expensive, and time-consuming, the prospect of recombinant toxoid vaccines against diseases caused by C. perfringens toxins is promising. In this study, nontoxic recombinant toxoids derived from α-, β- and ε-toxins of C. perfringens, namely, rCPA247-370 , rCPB and rEtxHP, respectively, were expressed in Escherichia coli. High levels of specific IgG antibodies and neutralizing antibodies against the toxins were detected in sera from calves vaccinated with either a single recombinant toxoid or a mixed cocktail of all three recombinant toxoids, indicating the potential of these recombinant toxoids to provide calves with protective immunity against enterotoxemia caused by C. perfringens.
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Affiliation(s)
- Zhigang Jiang
- Division of Livestock Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 427, Maduan Street, Harbin, 150001, China
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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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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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Dorca-Arévalo J, Pauillac S, Díaz-Hidalgo L, Martín-Satué M, Popoff MR, Blasi J. Correlation between in vitro cytotoxicity and in vivo lethal activity in mice of epsilon toxin mutants from Clostridium perfringens. PLoS One 2014; 9:e102417. [PMID: 25013927 PMCID: PMC4094505 DOI: 10.1371/journal.pone.0102417] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Accepted: 06/19/2014] [Indexed: 12/21/2022] Open
Abstract
Epsilon toxin (Etx) from Clostridium perfringens is a pore-forming protein with a lethal effect on livestock, producing severe enterotoxemia characterized by general edema and neurological alterations. Site-specific mutations of the toxin are valuable tools to study the cellular and molecular mechanism of the toxin activity. In particular, mutants with paired cysteine substitutions that affect the membrane insertion domain behaved as dominant-negative inhibitors of toxin activity in MDCK cells. We produced similar mutants, together with a well-known non-toxic mutant (Etx-H106P), as green fluorescent protein (GFP) fusion proteins to perform in vivo studies in an acutely intoxicated mouse model. The mutant (GFP-Etx-I51C/A114C) had a lethal effect with generalized edema, and accumulated in the brain parenchyma due to its ability to cross the blood-brain barrier (BBB). In the renal system, this mutant had a cytotoxic effect on distal tubule epithelial cells. The other mutants studied (GFP-Etx-V56C/F118C and GFP-Etx-H106P) did not have a lethal effect or cross the BBB, and failed to induce a cytotoxic effect on renal epithelial cells. These data suggest a direct correlation between the lethal effect of the toxin, with its cytotoxic effect on the kidney distal tubule cells, and the ability to cross the BBB.
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Affiliation(s)
- Jonatan Dorca-Arévalo
- Laboratory of Cellular and Molecular Neuroscience, Department of Pathology and Experimental Therapeutics, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain
- IDIBELL-Bellvitge Biomedical Research Institute, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Serge Pauillac
- Institut Pasteur, Unité des Bactéries anaérobies et Toxines, Paris, France
| | - Laura Díaz-Hidalgo
- Laboratory of Cellular and Molecular Neuroscience, Department of Pathology and Experimental Therapeutics, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Mireia Martín-Satué
- Laboratory of Cellular and Molecular Neuroscience, Department of Pathology and Experimental Therapeutics, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain
- IDIBELL-Bellvitge Biomedical Research Institute, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Michel R. Popoff
- Institut Pasteur, Unité des Bactéries anaérobies et Toxines, Paris, France
| | - Juan Blasi
- Laboratory of Cellular and Molecular Neuroscience, Department of Pathology and Experimental Therapeutics, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain
- IDIBELL-Bellvitge Biomedical Research Institute, L'Hospitalet de Llobregat, Barcelona, Spain
- * E-mail:
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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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Buys A, Macdonald R, Crafford J, Theron J. Development of a flow cytometric bead immunoassay and its assessment as a possible aid to potency evaluation of enterotoxaemia vaccines. J S Afr Vet Assoc 2014; 85:977. [PMID: 24832497 DOI: 10.4102/jsava.v85i1.977] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 05/13/2013] [Accepted: 06/14/2013] [Indexed: 11/01/2022] Open
Abstract
Enterotoxaemia, an economically important disease of sheep, goats and calves, is caused by systemic effects of the epsilon toxin produced by the anaerobic bacterium Clostridium perfringens type D. The only practical means of controlling the occurrence of enterotoxaemia is to immunise animals by vaccination. The vaccine is prepared by deriving a toxoid from the bacterial culture filtrate and the potency of the vaccine is tested with the in vivo mouse neutralisation test (MNT). Due to ethical, economic and technical reasons, alternative in vitro assays are needed. In this study an indirect cytometric bead immunoassay (I-CBA) was developed for use in vaccine potency testing and the results were compared with those obtained using an indirect enzyme-linked immunosorbent assay (I-ELISA) and the MNT. Sera were collected from guinea pigs immunised with three different production batches of enterotoxaemia vaccine and the levels of anti-epsilon toxin antibodies were determined. Although the intra- and inter-assay variability was satisfactory, epsilon antitoxin levels determined by both the I-ELISA and indirect cytometric bead immunoassay (I-CBA) tests were higher than those of the MNT assay. In contrast to the MNT, all of the serum samples were identified as having antitoxin levels above the required minimum (not less than 5 U/mL). These results indicate that the respective in vitro tests in their current formats are not yet suitable alternatives to the in vivo MNT. The growing demand for a more humane, cost-effective and efficient method for testing the potency of enterotoxaemia vaccines, however, provides a strong impetus for further optimisation and standardisation of the I-CBA assay but further analytical research is required.
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Affiliation(s)
- Angela Buys
- Quality Control Department, Onderstepoort Biological Products.
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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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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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Ivie SE, McClain MS. Identification of amino acids important for binding of Clostridium perfringens epsilon toxin to host cells and to HAVCR1. Biochemistry 2012; 51:7588-95. [PMID: 22938730 PMCID: PMC3534817 DOI: 10.1021/bi300690a] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Clostridium perfringens epsilon toxin belongs to the aerolysin-like family of pore-forming toxins and is one of the most potent bacterial toxins known. The epsilon toxin causes fatal enterotoxemia in sheep, goats, and possibly humans. Evidence indicates that the toxin binds to protein receptors including hepatitis A virus cellular receptor 1 (HAVCR1), but the region of the toxin responsible for cell binding has not been identified. In the present study, we identify amino acids within the epsilon toxin important for this cell interaction. Site-specific mutagenesis was used to investigate the role of a surface-accessible cluster of aromatic amino acids, and purified mutant proteins were tested in a series of cell-culture assays to assess cytotoxic activity and cell binding. When added to cells, four mutant proteins (Etx-Y29E, Etx-Y30E, Etx-Y36E and Etx-Y196E) were severely impaired in their ability to not only kill host cells, but also in their ability to permeabilize the plasma membrane. Circular dichroism spectroscopy and thermal stability studies revealed that the wild-type and mutant proteins were similarly folded. Additional experiments revealed that these mutant proteins were defective in binding to host cells and to HAVCR1. These data indicate that an amino acid motif including Y29, Y30, Y36, and Y196 is important for the ability of epsilon toxin to interact with cells and HAVCR1.
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Affiliation(s)
- Susan E. Ivie
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Mark S. McClain
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232
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Potential protective immunogenicity of recombinant Clostridium perfringens α–β2–β1 fusion toxin in mice, sows and cows. Vaccine 2011; 29:5459-66. [DOI: 10.1016/j.vaccine.2011.05.059] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2011] [Revised: 05/11/2011] [Accepted: 05/18/2011] [Indexed: 11/20/2022]
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Zhao Y, Kang L, Gao S, Zhou Y, Su L, Xin W, Su Y, Wang J. Expression and purification of functional Clostridium perfringens alpha and epsilon toxins in Escherichia coli. Protein Expr Purif 2011; 77:207-13. [DOI: 10.1016/j.pep.2011.02.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Revised: 01/13/2011] [Accepted: 02/01/2011] [Indexed: 11/30/2022]
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Bokori-Brown M, Savva CG, Fernandes da Costa SP, Naylor CE, Basak AK, Titball RW. Molecular basis of toxicity of Clostridium perfringens epsilon toxin. FEBS J 2011; 278:4589-601. [PMID: 21518257 DOI: 10.1111/j.1742-4658.2011.08140.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Clostridium perfringens ε-toxin is produced by toxinotypes B and D strains. The toxin is the aetiological agent of dysentery in newborn lambs but is also associated with enteritis and enterotoxaemia in goats, calves and foals. It is considered to be a potential biowarfare or bioterrorism agent by the US Government Centers for Disease Control and Prevention. The relatively inactive 32.9 kDa prototoxin is converted to active mature toxin by proteolytic cleavage, either by digestive proteases of the host, such as trypsin and chymotrypsin, or by C. perfringens λ-protease. In vivo, the toxin appears to target the brain and kidneys, but relatively few cell lines are susceptible to the toxin, and most work has been carried out using Madin-Darby canine kidney (MDCK) cells. The binding of ε-toxin to MDCK cells and rat synaptosomal membranes is associated with the formation of a stable, high molecular weight complex. The crystal structure of ε-toxin reveals similarity to aerolysin from Aeromonas hydrophila, parasporin-2 from Bacillus thuringiensis and a lectin from Laetiporus sulphureus. Like these toxins, ε-toxin appears to form heptameric pores in target cell membranes. The exquisite specificity of the toxin for specific cell types suggests that it binds to a receptor found only on these cells.
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Affiliation(s)
- Monika Bokori-Brown
- Biosciences, College of Life and Environmental Sciences, University of Exeter, UK
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Ivie SE, Fennessey CM, Sheng J, Rubin DH, McClain MS. Gene-trap mutagenesis identifies mammalian genes contributing to intoxication by Clostridium perfringens ε-toxin. PLoS One 2011; 6:e17787. [PMID: 21412435 PMCID: PMC3055893 DOI: 10.1371/journal.pone.0017787] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Accepted: 02/14/2011] [Indexed: 12/13/2022] Open
Abstract
The Clostridium perfringens ε-toxin is an extremely potent toxin associated with lethal toxemias in domesticated ruminants and may be toxic to humans. Intoxication results in fluid accumulation in various tissues, most notably in the brain and kidneys. Previous studies suggest that the toxin is a pore-forming toxin, leading to dysregulated ion homeostasis and ultimately cell death. However, mammalian host factors that likely contribute to ε-toxin-induced cytotoxicity are poorly understood. A library of insertional mutant Madin Darby canine kidney (MDCK) cells, which are highly susceptible to the lethal affects of ε-toxin, was used to select clones of cells resistant to ε-toxin-induced cytotoxicity. The genes mutated in 9 surviving resistant cell clones were identified. We focused additional experiments on one of the identified genes as a means of validating the experimental approach. Gene expression microarray analysis revealed that one of the identified genes, hepatitis A virus cellular receptor 1 (HAVCR1, KIM-1, TIM1), is more abundantly expressed in human kidney cell lines than it is expressed in human cells known to be resistant to ε-toxin. One human kidney cell line, ACHN, was found to be sensitive to the toxin and expresses a larger isoform of the HAVCR1 protein than the HAVCR1 protein expressed by other, toxin-resistant human kidney cell lines. RNA interference studies in MDCK and in ACHN cells confirmed that HAVCR1 contributes to ε-toxin-induced cytotoxicity. Additionally, ε-toxin was shown to bind to HAVCR1 in vitro. The results of this study indicate that HAVCR1 and the other genes identified through the use of gene-trap mutagenesis and RNA interference strategies represent important targets for investigation of the process by which ε-toxin induces cell death and new targets for potential therapeutic intervention.
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Affiliation(s)
- Susan E. Ivie
- Division of Infectious Disease, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Christine M. Fennessey
- Division of Infectious Disease, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Jinsong Sheng
- Division of Infectious Disease, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Donald H. Rubin
- Division of Infectious Disease, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- Research Medicine, VA Tennessee Valley Healthcare System, Nashville, Tennessee, United States of America
| | - Mark S. McClain
- Division of Infectious Disease, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- * E-mail:
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Lobato FC, Lima CG, Assis RA, Pires PS, Silva RO, Salvarani FM, Carmo AO, Contigli C, Kalapothakis E. Potency against enterotoxemia of a recombinant Clostridium perfringens type D epsilon toxoid in ruminants. Vaccine 2010; 28:6125-7. [DOI: 10.1016/j.vaccine.2010.07.046] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Revised: 07/14/2010] [Accepted: 07/14/2010] [Indexed: 10/19/2022]
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Lebrun M, Mainil JG, Linden A. Cattle enterotoxaemia and Clostridium perfringens
: description, diagnosis and prophylaxis. Vet Rec 2010; 167:13-22. [DOI: 10.1136/vr.167.1.12] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- M. Lebrun
- Association de Santé et d'Identification Animale; Allée des Artisans 2 5590 Ciney Belgium
| | - J. G. Mainil
- Bacteriology Section; Department of Infectious Diseases; Faculty of Veterinary Medicine; University of Liège; B43A Boulevard de Colonster 20 4000 Liège Belgium
| | - A. Linden
- Bacteriology Section; Department of Infectious Diseases; Faculty of Veterinary Medicine; University of Liège; B43A Boulevard de Colonster 20 4000 Liège Belgium
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Abstract
Clostridia produce the highest number of toxins of any type of bacteria and are involved in severe diseases in humans and other animals. Most of the clostridial toxins are pore-forming toxins responsible for gangrenes and gastrointestinal diseases. Among them, perfringolysin has been extensively studied and it is the paradigm of the cholesterol-dependent cytolysins, whereas Clostridium perfringens epsilon-toxin and Clostridium septicum alpha-toxin, which are related to aerolysin, are the prototypes of clostridial toxins that form small pores. Other toxins active on the cell surface possess an enzymatic activity, such as phospholipase C and collagenase, and are involved in the degradation of specific cell-membrane or extracellular-matrix components. Three groups of clostridial toxins have the ability to enter cells: large clostridial glucosylating toxins, binary toxins and neurotoxins. The binary and large clostridial glucosylating toxins alter the actin cytoskeleton by enzymatically modifying the actin monomers and the regulatory proteins from the Rho family, respectively. Clostridial neurotoxins proteolyse key components of neuroexocytosis. Botulinum neurotoxins inhibit neurotransmission at neuromuscular junctions, whereas tetanus toxin targets the inhibitory interneurons of the CNS. The high potency of clostridial toxins results from their specific targets, which have an essential cellular function, and from the type of modification that they induce. In addition, clostridial toxins are useful pharmacological and biological tools.
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Affiliation(s)
- Michel R Popoff
- Institut Pasteur, Bactéries Anaérobies et Toxines, 75724 Paris cedex 15, France.
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Titball RW. Clostridium perfringens vaccines. Vaccine 2009; 27 Suppl 4:D44-7. [DOI: 10.1016/j.vaccine.2009.07.047] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2009] [Accepted: 07/15/2009] [Indexed: 10/20/2022]
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Pelish TM, McClain MS. Dominant-negative inhibitors of the Clostridium perfringens epsilon-toxin. J Biol Chem 2009; 284:29446-53. [PMID: 19720828 PMCID: PMC2785577 DOI: 10.1074/jbc.m109.021782] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2009] [Revised: 08/24/2009] [Indexed: 01/27/2023] Open
Abstract
The Clostridium perfringens epsilon-toxin is responsible for a severe, often lethal intoxication. In this study, we characterized dominant-negative inhibitors of the epsilon-toxin. Site-specific mutations were introduced into the gene encoding epsilon-toxin, and recombinant proteins were expressed in Escherichia coli. Paired cysteine substitutions were introduced at locations predicted to form a disulfide bond. One cysteine in each mutant was introduced into the membrane insertion domain of the toxin; the second cysteine was introduced into the protein backbone. Mutant proteins with cysteine substitutions at amino acid positions I51/A114 and at V56/F118 lacked detectable cytotoxic activity in a MDCK cell assay. Cytotoxic activity could be reconstituted in both mutant proteins by incubation with dithiothreitol, indicating that the lack of cytotoxic activity was attributable to the formation of a disulfide bond. Fluorescent labeling of the cysteines also indicated that the introduced cysteines participated in a disulfide bond. When equimolar mixtures of wild-type epsilon-toxin and mutant proteins were added to MDCK cells, the I51C/A114C and V56C/F118C mutant proteins each inhibited the activity of wild-type epsilon-toxin. Further analysis of the inhibitory activity of the I51C/A114C and V56C/F118C mutant proteins indicated that these proteins inhibit the ability of the active toxin to form stable oligomeric complexes in the context of MDCK cells. These results provide further insight into the properties of dominant-negative inhibitors of oligomeric pore-forming toxins and provide the basis for developing new therapeutics for treating intoxication by epsilon-toxin.
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Affiliation(s)
- Teal M. Pelish
- From the Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Mark S. McClain
- From the Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232
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McClain MS, Cover TL. Functional analysis of neutralizing antibodies against Clostridium perfringens epsilon-toxin. Infect Immun 2007; 75:1785-93. [PMID: 17261609 PMCID: PMC1865726 DOI: 10.1128/iai.01643-06] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2006] [Revised: 11/13/2006] [Accepted: 01/15/2007] [Indexed: 11/20/2022] Open
Abstract
The Clostridium perfringens epsilon-toxin causes a severe, often fatal illness (enterotoxemia) characterized by cardiac, pulmonary, kidney, and brain edema. In this study, we examined the activities of two neutralizing monoclonal antibodies against the C. perfringens epsilon-toxin. Both antibodies inhibited epsilon-toxin cytotoxicity towards cultured MDCK cells and inhibited the ability of the toxin to form pores in the plasma membranes of cells, as shown by staining cells with the membrane-impermeant dye 7-aminoactinomycin D. Using an antibody competition enzyme-linked immunosorbent assay (ELISA), a peptide array, and analysis of mutant toxins, we mapped the epitope recognized by one of the neutralizing monoclonal antibodies to amino acids 134 to 145. The antibody competition ELISA and analysis of mutant toxins suggest that the second neutralizing monoclonal antibody also recognizes an epitope in close proximity to this region. The region comprised of amino acids 134 to 145 overlaps an amphipathic loop corresponding to the putative membrane insertion domain of the toxin. Identifying the epitopes recognized by these neutralizing antibodies constitutes an important first step in the development of therapeutic agents that could be used to counter the effects of the epsilon-toxin.
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Affiliation(s)
- Mark S McClain
- Department of Medicine, Division of Infectious Diseases, A2200 Medical Center North, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
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Pappas G, Panagopoulou P, Christou L, Akritidis N. Category B Potential Bioterrorism Agents: Bacteria, Viruses, Toxins, and Foodborne and Waterborne Pathogens. Infect Dis Clin North Am 2006; 20:395-421, x. [PMID: 16762744 DOI: 10.1016/j.idc.2006.02.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Georgios Pappas
- Institute for Continuing Medical Education of Ioannina, Velissariou 15-19, 45221 Ioannina, Greece.
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Schoepe H, Neubauer A, Schlapp T, Wieler LH, Baljer G. Immunization with an alphatoxin variant 121A/91-R212H protects mice against Clostridium perfringens alphatoxin. Anaerobe 2006; 12:44-8. [PMID: 16701610 DOI: 10.1016/j.anaerobe.2005.06.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2004] [Revised: 05/09/2005] [Accepted: 06/03/2005] [Indexed: 10/25/2022]
Abstract
As shown previously, a recombinant alphatoxin variant (rAT121A/91) constructed from the naturally occurring Clostridium perfringens mutant strain 121A/91, was devoid of enzymatic (PLC), hemolytic and lethal activity (18). In the present study, the recombinant variant was altered by an oligonucleotide-directed reversion of an arginine in position 212 for a histidine residue, corresponding to the sequence of the wild-type alphatoxin. The new variant rAT121A/91R212H proved to be negative in enzymatic, hemolytic and lethal activity as well. RAT121A/91 as well as rAT121A/91R212H was used for i.p. immunization of balb/c mice. The immune response was studied in ELISA as well as in the mouse neutralization test. Furthermore, immunized mice were challenged by i.p. application of active C. perfringens alphatoxin. In all immunized groups, mice developed high anti-alphatoxin titers (up to 1:128000). Antisera of both groups were able to reduce the hemolytic effect of native alphatoxin with predominance of anti-rAT121A/91R212H sera. During neutralization experiments, mice receiving a mixture of anti-rAT121A/91R212H and wild-type toxin were protected completely, whereas an anti-rAT121A/91/toxin mixture prolonged time until death but failed in protection. I.p immunization with rAT121A/91R212H yielded a significant protection rate (76%) when mice were challenged intraperitoneal with wild-type toxin. Our cumulative data indicates that the reversion of arginine in position 212 to histidine for rAT121A/91R212H was necessary to induce production of protective antibodies against wild-type alphatoxin of C. perfringens.
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Affiliation(s)
- Heike Schoepe
- Institut für Hygiene und Infektionskrankheiten der Tiere, Justus-Liebig-Universität Giessen, D-35392 Giessen, Germany.
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Grubhoffer L, Golovchenko M, Vancová M, Zacharovová-Slavícková K, Rudenko N, Oliver JH. Lyme borreliosis: insights into tick-/host-borrelia relations. Folia Parasitol (Praha) 2006; 52:279-94. [PMID: 16405291 DOI: 10.14411/fp.2005.039] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Lyme borreliosis (LB) is a serious infectious disease of humans and some domestic animals in temperate regions of the Northern Hemisphere. It is caused by certain spirochetes in the Borrelia burgdorferi sensu lato (s.l.) species complex. The complex consists of 11 species (genospecies). Borrelia burgdorferi sensu stricto (s.s.), Borrelia garinii and Borrelia afzelii are the major agents of human disease. Borrelia burgdorferi s.l. species are transmitted mainly by ticks belonging to the Ixodes ricinus species complex plus a few additional species not currently assigned to the complex. B. burgdorferi infections may produce an acute or chronic disease with a wide array of clinical symptoms such as erythema migrans (EM), carditis, arthritis, neuroborreliosis, and acrodermatitis chronica atrophicans (ACA). Differences in LB spirochetes 'genospecies' and strains/isolates determine the occurrence and severity of this multi-system disease. Accurate and reliable identification of the LB spirochetes in ticks as well as knowledge of their prevalence are essential for prevention against the disease and development of an effective vaccine. An overview of the knowledge of molecular factors with emphasis on potential protein-carbohydrate interactions in the tick-borrelia system is the main focus of this review.
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Affiliation(s)
- Libor Grubhoffer
- Institute of Parasitology, Academy of Sciences of the Czech Republic and Faculty of Biological Sciences, University of South Bohemia, Branisovska 31, 370 05 Ceské Budejovice, Czech Republic.
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Mantis NJ. Vaccines against the category B toxins: Staphylococcal enterotoxin B, epsilon toxin and ricin. Adv Drug Deliv Rev 2005; 57:1424-39. [PMID: 15935880 DOI: 10.1016/j.addr.2005.01.017] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2004] [Accepted: 01/25/2005] [Indexed: 01/15/2023]
Abstract
The threat of bioterrorism worldwide has accelerated the demand for the development of therapies and vaccines against the Category B toxins: staphylococcal enterotoxin B (SEB), epsilon toxin (ETX) produced by Clostridium perfringens types B and D, and ricin, a natural product of the castor bean. The diverse and unique nature of these toxins poses a challenge to vaccinologists. While formalin-inactivated toxins can successfully induce antibody-mediated protection in animals, their usefulness in humans is limited because of potential safety concerns. For this reason, research is now aimed at developing recombinant, attenuated vaccines based on a detailed understanding of the molecular mechanisms by which these toxins function. Vaccine development is further complicated by the fact that as bioterrorism agents, SEB, ETX and ricin would most likely be disseminated as aerosols or in food/water supplies. Our understanding of the mechanisms by which these toxins cross mucosal surfaces, and importance of mucosal immunity in preventing toxin uptake is only rudimentary.
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Affiliation(s)
- Nicholas J Mantis
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, NY 12208, USA.
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Smedley JG, Fisher DJ, Sayeed S, Chakrabarti G, McClane BA. The enteric toxins of Clostridium perfringens. Rev Physiol Biochem Pharmacol 2004; 152:183-204. [PMID: 15517462 DOI: 10.1007/s10254-004-0036-2] [Citation(s) in RCA: 148] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
The Gram-positive pathogen Clostridium perfringens is a major cause of human and veterinary enteric disease largely because this bacterium can produce several toxins when present inside the gastrointestinal tract. The enteric toxins of C. perfringens share two common features: (1) they are all single polypeptides of modest (approximately 25-35 kDa) size, although lacking in sequence homology, and (2) they generally act by forming pores or channels in plasma membranes of host cells. These enteric toxins include C. perfringens enterotoxin (CPE), which is responsible for the symptoms of a common human food poisoning and acts by forming pores after interacting with intestinal tight junction proteins. Two other C. perfringens enteric toxins, epsilon-toxin (a bioterrorism select agent) and beta-toxin, cause veterinary enterotoxemias when absorbed from the intestines; beta- and epsilon-toxins then apparently act by forming oligomeric pores in intestinal or extra-intestinal target tissues. The action of a newly discovered C. perfringens enteric toxin, beta2 toxin, has not yet been defined but precedent suggests it might also be a pore-former. Experience with other clostridial toxins certainly warrants continued research on these C. perfringens enteric toxins to develop their potential as therapeutic agents and tools for cellular biology.
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Affiliation(s)
- J G Smedley
- University of Pittsburgh School of Medicine, Department of Molecular Genetics and Biochemistry, Pittsburgh, PA 15261, USA
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