1
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Atitkar RR, Hauser JR, Melton-Celsa AR. Shiga Toxin (Stx) Phage-Encoded Lytic Genes Are Not Required for the Mouse Virulence of O157:H7 Escherichia coli Stx2-Producing Clinical Isolates. Microbiol Spectr 2023; 11:e0037223. [PMID: 37022201 PMCID: PMC10269767 DOI: 10.1128/spectrum.00372-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 03/17/2023] [Indexed: 04/07/2023] Open
Abstract
Shiga toxin (Stx)-producing Escherichia coli (STEC) is a major cause of foodborne diarrheal illness in the United States and globally, and serotype O157:H7 is frequently associated with STEC outbreaks and sporadic cases in the United States. Severe systemic diseases associated with STEC are mediated by Stx types, particularly subtype Stx2a, encoded on inducible bacteriophages. We previously identified two STEC O157:H7 clinical isolates, JH2010 and JH2012, that exhibit a large difference in virulence in a streptomycin (Str)-treated mouse model. In this study, we aimed to identify a genetic basis for the difference in virulence between those strains. Comparison of the stx2a phage sequences showed that JH2012 lacks the lytic genes S and R on the phage genome. We also demonstrated that compared to JH2012 cultures, cultures of JH2010 released more Stx2 into the supernatant and were more sensitive to bacterial lysis during growth with ciprofloxacin (Cip), an inducer of stx phages. We therefore generated an stx2a phage SR deletion mutant strain of JH2010 to determine if those genes were responsible for the high virulence of that strain. We found that deletion of the SR genes from the stx2a phage in JH2010, and another O157:H7 strain, JH2016, resulted in increased cellular retention of Stx2, but there was no difference in virulence compared to the wild-type strains. Our results indicate that the stx2a phage SR genes are involved in Stx2 localization and phage-mediated cell lysis in vitro but that they are not required in wild-type STEC strains for virulence in a mouse model. IMPORTANCE The release of Stx from STEC has been thought to be tied to phage-mediated lysis of the host bacterial cell. In this study, we found that the stx2a phage lytic genes are not required for the virulence of pathogenic O157:H7 clinical isolates in a murine model of STEC infection or for release of Stx2a into the supernatant of bacterial cultures. These results point to an alternate mechanism for Stx2a release from STEC strains.
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Affiliation(s)
- R. R. Atitkar
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, Maryland, USA
| | - J. R. Hauser
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, Maryland, USA
| | - A. R. Melton-Celsa
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
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2
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Shimizu T, Onuki M, Suzuki S, Hirai S, Yokoyama E, Matsumoto A, Hamabata T. Enhanced production of Shiga toxin 1 in enterohaemorrhagic Escherichia coli by oxygen. MICROBIOLOGY (READING, ENGLAND) 2021; 167. [PMID: 34951398 DOI: 10.1099/mic.0.001122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Enterohaemorrhagic Escherichia coli (EHEC) produces Shiga toxin 1 (Stx1) and Shiga toxin 2 (Stx2). Although stx1 and stx2 were found within the late operons of the Stx-encoding phages (Stx-phages), stx1 could mainly be transcribed from the stx1 promoter (P Stx1), which represents the functional operator-binding site (Fur box) for the transcriptional regulator Fur (ferric uptake regulator), upstream of stx1. In this study, we found that the production of Stx1 by EHEC was affected by oxygen concentration. Increased Stx1 production in the presence of oxygen is dependent on Fur, which is an Fe2+-responsive transcription factor. The intracellular Fe2+ pool was lower under microaerobic conditions than under anaerobic conditions, suggesting that lower Fe2+ availability drove the formation of less Fe2+-Fur, less DNA binding to the P Stx1 region, and an increase in Stx1 production.
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Affiliation(s)
- Takeshi Shimizu
- Departments of Molecular Infectiology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan
| | - Manami Onuki
- Departments of Molecular Infectiology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan
| | - Shin Suzuki
- Departments of Molecular Infectiology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan
| | - Shinichiro Hirai
- Department of Infectious Disease Risk Management Center, National Institute of Infectious Diseases, 4-7-1 Gakuen, Musashi-murayama, Tokyo 208-0011, Japan
| | - Eiji Yokoyama
- Division of Bacteriology, Chiba Prefectural Institute of Public Health, 666-2 Nitona, Chuo-ku, Chiba, 260-8715, Japan
| | - Akio Matsumoto
- Department of Aging Pharmacology, Faculty of Medicine, Toho University, 5-21-16 Omori-Nishi, Ota-ku, Tokyo, 143-8540, Japan
| | - Takashi Hamabata
- Department of Infectious Disease, Research Institute, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo, 162-8655, Japan
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3
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Kanemaru K, Goto T, Badr HA, Yokoigawa K. Determination of binding affinity of poly-γ-glutamate to Shiga toxin. J Food Biochem 2018. [DOI: 10.1111/jfbc.12538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Kaori Kanemaru
- Graduate School of Integrated Arts and Sciences; Tokushima University, 1-1 Minamijosanjima-cho; Tokushima 770-8502 Japan
- Faculty of Bioscience and Bioindustry; Tokushima University, 2-1 Minamijosanjima-cho; Tokushima , 770-8513 Japan
| | - Tsukie Goto
- Graduate School of Integrated Arts and Sciences; Tokushima University, 1-1 Minamijosanjima-cho; Tokushima 770-8502 Japan
- Department of Science for Human Health; Junior College, Shikoku University, 123-1 Ebisuno, Furukawa, Ojin-cho; Tokushima 771-1192 Japan
| | - Hoida Ali Badr
- Graduate School of Integrated Arts and Sciences; Tokushima University, 1-1 Minamijosanjima-cho; Tokushima 770-8502 Japan
| | - Kumio Yokoigawa
- Graduate School of Integrated Arts and Sciences; Tokushima University, 1-1 Minamijosanjima-cho; Tokushima 770-8502 Japan
- Faculty of Bioscience and Bioindustry; Tokushima University, 2-1 Minamijosanjima-cho; Tokushima , 770-8513 Japan
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4
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Yahiro K, Nagasawa S, Ichimura K, Takeuchi H, Ogura K, Tsutsuki H, Shimizu T, Iyoda S, Ohnishi M, Iwase H, Moss J, Noda M. Mechanism of inhibition of Shiga-toxigenic Escherichia coli SubAB cytotoxicity by steroids and diacylglycerol analogues. Cell Death Discov 2018. [PMID: 29531819 PMCID: PMC5841432 DOI: 10.1038/s41420-017-0007-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Shiga toxigenic Escherichia coli (STEC) are responsible for a worldwide foodborne disease, which is characterized by severe bloody diarrhea and hemolytic uremic syndrome (HUS). Subtilase cytotoxin (SubAB) is a novel AB5 toxin, which is produced by Locus for Enterocyte Effacement (LEE)-negative STEC. Cleavage of the BiP protein by SubAB induces endoplasmic reticulum (ER) stress, followed by induction of cytotoxicity in vitro or lethal severe hemorrhagic inflammation in mice. Here we found that steroids and diacylglycerol (DAG) analogues (e.g., bryostatin 1, Ingenol-3-angelate) inhibited SubAB cytotoxicity. In addition, steroid-induced Bcl-xL expression was a key step in the inhibition of SubAB cytotoxicity. Bcl-xL knockdown increased SubAB-induced apoptosis in steroid-treated HeLa cells, whereas SubAB-induced cytotoxicity was suppressed in Bcl-xL overexpressing cells. In contrast, DAG analogues suppressed SubAB activity independent of Bcl-xL expression at early time points. Addition of Shiga toxin 2 (Stx2) with SubAB to cells enhanced cytotoxicity even in the presence of steroids. In contrast, DAG analogues suppressed cytotoxicity seen in the presence of both toxins. Here, we show the mechanism by which steroids and DAG analogues protect cells against SubAB toxin produced by LEE-negative STEC.
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Affiliation(s)
- Kinnosuke Yahiro
- 1Department of Molecular Infectiology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Sayaka Nagasawa
- 2Department of Legal Medicine, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Kimitoshi Ichimura
- 1Department of Molecular Infectiology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Hiroki Takeuchi
- 1Department of Molecular Infectiology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Kohei Ogura
- 3Pathogenic Microbe Laboratory, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan
| | - Hiroyasu Tsutsuki
- 4Department of Microbiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Takeshi Shimizu
- 1Department of Molecular Infectiology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Sunao Iyoda
- 5Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Makoto Ohnishi
- 5Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Hirotaro Iwase
- 2Department of Legal Medicine, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Joel Moss
- 6Cardiovascular and Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD USA
| | - Masatoshi Noda
- 1Department of Molecular Infectiology, Graduate School of Medicine, Chiba University, Chiba, Japan
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5
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Ichimura K, Shimizu T, Matsumoto A, Hirai S, Yokoyama E, Takeuchi H, Yahiro K, Noda M. Nitric oxide-enhanced Shiga toxin production was regulated by Fur and RecA in enterohemorrhagic Escherichia coli O157. Microbiologyopen 2017; 6. [PMID: 28294553 PMCID: PMC5552940 DOI: 10.1002/mbo3.461] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 01/20/2017] [Accepted: 02/01/2017] [Indexed: 12/27/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) produces Shiga toxin 1 (Stx1) and Shiga toxin 2 (Stx2). Nitric oxide (NO), which acts as an antimicrobial defense molecule, was found to enhance the production of Stx1 and Stx2 in EHEC under anaerobic conditions. Although EHEC O157 has two types of anaerobic NO reductase genes, an intact norV and a deleted norV, in the deleted norV‐type EHEC, a high concentration of NO (12–29 μmol/L, maximum steady‐state concentration) is required for enhanced Stx1 production and a low concentration of NO (~12 μmol/L, maximum steady‐state concentration) is sufficient for enhanced Stx2 production under anaerobic conditions. These results suggested that different concentration thresholds of NO elicit a discrete set of Stx1 and Stx2 production pathways. Moreover, the enhancement of Shiga toxin production in the intact norV‐type EHEC required treatment with a higher concentration of NO than was required for enhancement of Shiga toxin production in the deleted norV‐type EHEC, suggesting that the specific NorV type plays an important role in the level of enhancement of Shiga toxin production in response to NO. Finally, Fur derepression and RecA activation in EHEC were shown to participate in the NO‐enhanced Stx1 and Stx2 production, respectively.
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Affiliation(s)
- Kimitoshi Ichimura
- Departments of Molecular Infectiology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Takeshi Shimizu
- Departments of Molecular Infectiology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Akio Matsumoto
- Pharmacology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Shinichiro Hirai
- Division of Bacteriology, Chiba Prefectural Institute of Public Health, Chiba, Japan
| | - Eiji Yokoyama
- Division of Bacteriology, Chiba Prefectural Institute of Public Health, Chiba, Japan
| | - Hiroki Takeuchi
- Departments of Molecular Infectiology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Kinnosuke Yahiro
- Departments of Molecular Infectiology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Masatoshi Noda
- Departments of Molecular Infectiology, Graduate School of Medicine, Chiba University, Chiba, Japan
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6
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The Shiga toxin 2 production level in enterohemorrhagic Escherichia coli O157:H7 is correlated with the subtypes of toxin-encoding phage. Sci Rep 2015; 5:16663. [PMID: 26567959 PMCID: PMC4645166 DOI: 10.1038/srep16663] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 10/19/2015] [Indexed: 01/21/2023] Open
Abstract
Enterohemorrhagic E. coli (EHEC) causes diarrhea and hemorrhagic colitis with life-threatening complications, such as hemolytic uremic syndrome. Their major virulence factor is Shiga toxin (Stx), which is encoded by bacteriophages. Of the two types of Stx, the production of Stx2, particularly that of Stx2a (a subtype of Stx2), is a major risk factor for severe EHEC infections, but the Stx2 production level is highly variable between strains. Here, we define four major and two minor subtypes of Stx2a-encoding phages according to their replication proteins. The subtypes are correlated with Stx2a titers produced by the host O157 strains, suggesting a critical role of the phage subtype in determining the Stx2a production level. We further show that one of the two subclades in the clade 8, a proposed hyper-virulent lineage of O157, carries the Stx2 phage subtype that confers the highest Stx2 production to the host strain. The presence of this subclade may explain the proposed high virulence potential of clade 8. These results provide novel insights into the variation in virulence among O157 strains and highlight the role of phage variation in determining the production level of the virulence factors that phages encode.
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7
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Grau-Leal F, Quirós P, Martínez-Castillo A, Muniesa M. Free Shiga toxin 1-encoding bacteriophages are less prevalent than Shiga toxin 2 phages in extraintestinal environments. Environ Microbiol 2015; 17:4790-801. [DOI: 10.1111/1462-2920.13053] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 08/31/2015] [Accepted: 09/11/2015] [Indexed: 11/30/2022]
Affiliation(s)
- Ferran Grau-Leal
- Department of Microbiology; University of Barcelona; Diagonal 643, Annex, Floor 0 Barcelona E-08028 Spain
| | - Pablo Quirós
- Department of Microbiology; University of Barcelona; Diagonal 643, Annex, Floor 0 Barcelona E-08028 Spain
| | | | - Maite Muniesa
- Department of Microbiology; University of Barcelona; Diagonal 643, Annex, Floor 0 Barcelona E-08028 Spain
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8
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Noda M. [Studies on the mode of action of bacterial AB5 toxins]. Nihon Saikingaku Zasshi 2013; 68:299-311. [PMID: 23985936 DOI: 10.3412/jsb.68.299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Bacterial AB5 toxins are proteins, produced by pathogenic bacteria including of Vibrio cholerae, Shigella dysenteriae, and enterohaemorrhagic Escherichia coli, which are usually released into the extracellular medium and cause disease by killing or altering the metabolism of target eukaryotic cells. The toxins are usually composed of one A subunit (a toxic domain) and five B subunits (a receptor-binding domain). This article overviews the characteristics and mode of actions of AB5 toxins including cholera toxin, Shiga-like toxin, and subtilase cytotoxin, and highlights current topics related to the roles of the effectors in promoting bacterial infection.
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Affiliation(s)
- Masatoshi Noda
- Department of Molecular Infectiology, Chiba University Graduate School of Medicine, Japan
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9
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Neri P, Tokoro S, Sugiyama T, Umeda K, Shimizu T, Tsuji T, Kodama Y, Mori H. Recombinant Shiga toxin B subunit can induce neutralizing immunoglobulin Y antibody. Biol Pharm Bull 2012; 35:917-23. [PMID: 22687484 DOI: 10.1248/bpb.35.917] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previously, we have shown that chickens immunized with Shiga toxin (Stx) produce Stx-neutralizing egg yolk immunoglobulin Y (IgY) antibody. The anti-Stx-1 IgY and anti-Stx-2 IgY exert their neutralizing activity through their antibody activity against the B subunit of the toxin but not the A subunit. In the present study, chickens were immunized with recombinant Stx-1 B subunit (rStx-1B) and recombinant Stx-2 B subunit (rStx-2B). Induced anti-rStx-1B and anti-rStx-2B IgY neutralized the toxicity of Stx-1 and Stx-2 against HeLa 229 cells. The neutralizing activity of anti-rStx-1B IgY on Stx-1 was almost 10 times stronger than that of anti-Stx-1 IgY, and that of anti-rStx-2B IgY was 2.6 times stronger than that of anti-Stx-2 IgY. Anti-rStx-1B and anti-rStx-2B IgY reacted with multimeric and monomeric forms of the B subunits in contrast to anti-Stx-1 and anti-Stx-2 IgY that reacted with only the multimeric form. These results indicated that recombinant B subunits were promising antigens for induction of neutralizing antibodies in chickens.
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Affiliation(s)
- Paola Neri
- Microbiology, Department of Biopharmaceutical Sciences, Gifu Pharmaceutical University, Japan
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10
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Shimizu T, Tsutsuki H, Matsumoto A, Nakaya H, Noda M. The nitric oxide reductase of enterohaemorrhagic Escherichia coli plays an important role for the survival within macrophages. Mol Microbiol 2012; 85:492-512. [DOI: 10.1111/j.1365-2958.2012.08122.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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11
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Fogg PCM, Saunders JR, McCarthy AJ, Allison HE. Cumulative effect of prophage burden on Shiga toxin production in Escherichia coli. MICROBIOLOGY-SGM 2011; 158:488-497. [PMID: 22096150 DOI: 10.1099/mic.0.054981-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Shigatoxigenic Escherichia coli (STEC) such as E. coli O157 are significant human pathogens, capable of producing severe, systemic disease outcomes. The more serious symptoms associated with STEC infection are primarily the result of Shiga toxin (Stx) production, directed by converting Stx bacteriophages. During phage-mediated replication and host cell lysis, the toxins are released en masse from the bacterial cells, and the severity of disease is linked inexorably to toxin load. It is common for a single bacterial host to harbour more than one heterogeneous Stx prophage, and it has also been recently proven that multiple isogenic prophage copies can exist in a single cell, contrary to the lambda immunity model. It is possible that in these multiple lysogens there is an increased potential for production of Stx. This study investigated the expression profiles of single and double isogenic lysogens of Stx phage 24(B) using quantitative PCR to examine transcription levels, and a reporter gene construct as a proxy for the translation levels of stx transcripts. Toxin gene expression in double lysogens was in excess of the single lysogen counterpart, both in the prophage state and after induction of the lytic life cycle. In addition, double lysogens were found to be more sensitive to an increased induction stimulus than single lysogens, suggesting that maintenance of a stable prophage is less likely when multiple phage genome copies are present. Overall, these data demonstrate that the phenomenon of multiple lysogeny in STEC has the potential to impact upon disease pathology through increased toxin load.
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Affiliation(s)
- Paul C M Fogg
- University of Liverpool, Microbiology Research Group, Institute of Integrative Biology, Biosciences Building, Crown Street, Liverpool, Merseyside L69 7ZB, UK
| | - Jon R Saunders
- University of Liverpool, Microbiology Research Group, Institute of Integrative Biology, Biosciences Building, Crown Street, Liverpool, Merseyside L69 7ZB, UK
| | - Alan J McCarthy
- University of Liverpool, Microbiology Research Group, Institute of Integrative Biology, Biosciences Building, Crown Street, Liverpool, Merseyside L69 7ZB, UK
| | - Heather E Allison
- University of Liverpool, Microbiology Research Group, Institute of Integrative Biology, Biosciences Building, Crown Street, Liverpool, Merseyside L69 7ZB, UK
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12
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Yamasaki T, Suzuki A, Shimizu T, Watarai M, Hasebe R, Horiuchi M. Characterization of intracellular localization of PrP(Sc) in prion-infected cells using a mAb that recognizes the region consisting of aa 119-127 of mouse PrP. J Gen Virol 2011; 93:668-680. [PMID: 22090211 DOI: 10.1099/vir.0.037101-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Generation of an abnormal isoform of the prion protein (PrP(Sc)) is a key aspect of the propagation of prions. Elucidation of the intracellular localization of PrP(Sc) in prion-infected cells facilitates the understanding of the cellular mechanism of prion propagation. However, technical improvement in PrP(Sc)-specific detection is required for precise analysis. Here, we show that the mAb 132, which recognizes the region adjacent to the most amyloidogenic region of PrP, is useful for PrP(Sc)-specific detection by immunofluorescence assay in cells pre-treated with guanidine thiocyanate. Extensive analysis of the intracellular localization of PrP(Sc) in prion-infected cells using mAb 132 revealed the presence of PrP(Sc) throughout endocytic compartments. In particular, some of the granular PrP(Sc) signals that were clustered at peri-nuclear regions appeared to be localized in an endocytic recycling compartment through which exogenously loaded transferrin, shiga and cholera toxin B subunits were transported. The granular PrP(Sc) signals at peri-nuclear regions were dispersed to the peripheral regions including the plasma membrane during incubation at 20 °C, at which temperature transport from the plasma membrane to peri-nuclear regions was impaired. Conversely, dispersed PrP(Sc) signals appeared to return to peri-nuclear regions within 30 min during subsequent incubation at 37 °C, following which PrP(Sc) at peri-nuclear regions appeared to redisperse again to peripheral regions over the next 30 min incubation. These results suggest that PrP(Sc) is dynamically transported along with the membrane trafficking machinery of cells and that at least some PrP(Sc) circulates between peri-nuclear and peripheral regions including the plasma membrane via an endocytic recycling pathway.
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Affiliation(s)
- Takeshi Yamasaki
- Laboratory of Veterinary Hygiene, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan
| | - Akio Suzuki
- Laboratory of Veterinary Hygiene, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan
| | - Takeshi Shimizu
- Department of Molecular Infectiology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chiba 260-8670, Japan
| | - Masahisa Watarai
- Department of Veterinary Public Health, Faculty of Agriculture, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
| | - Rie Hasebe
- Laboratory of Veterinary Hygiene, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan
| | - Motohiro Horiuchi
- Laboratory of Veterinary Hygiene, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan
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13
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Neri P, Tokoro S, Kobayashi R, Sugiyama T, Umeda K, Shimizu T, Tsuji T, Kodama Y, Oguma K, Mori H. Specific egg yolk immunoglobulin as a new preventive approach for Shiga-toxin-mediated diseases. PLoS One 2011; 6:e26526. [PMID: 22028896 PMCID: PMC3197529 DOI: 10.1371/journal.pone.0026526] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2011] [Accepted: 09/28/2011] [Indexed: 11/19/2022] Open
Abstract
Shiga toxins (Stxs) are involved in the development of severe systemic complications associated with enterohemorrhagic Escherichia coli (EHEC) infection. Various neutralizing agents against Stxs are under investigation for management of EHEC infection. In this study, we immunized chickens with formalin-inactivated Stx-1 or Stx-2, and obtained immunoglobulin Y (IgY) from the egg yolk. Anti-Stx-1 IgY and anti-Stx-2 IgY recognized the corresponding Stx A subunit and polymeric but not monomeric B subunit. Anti-Stx-1 IgY and anti-Stx-2 IgY suppressed the cytotoxicity of Stx-1 and Stx-2 to HeLa 229 cells, without cross-suppressive activity. The suppressive activity of these IgY was abrogated by pre-incubation with the corresponding recombinant B subunit, which suggests that the antibodies directed to the polymeric B subunits were predominantly involved in the suppression. In vivo, the intraperitoneal or intravenous administration of these IgY rescued mice from death caused by intraperitoneal injection of the corresponding toxin at a lethal dose. Moreover, oral administration of anti-Stx-2 IgY reduced the mortality of mice infected intestinally with EHEC O157:H7. Our results therefore suggest that anti-Stx IgY antibodies may be considered as preventive agents for Stx-mediated diseases in EHEC infection.
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Affiliation(s)
- Paola Neri
- Microbiology, Department of Biopharmaceutical Sciences, Gifu Pharmaceutical University, Gifu, Japan
| | - Shunji Tokoro
- Microbiology, Department of Biopharmaceutical Sciences, Gifu Pharmaceutical University, Gifu, Japan
| | - Ryo Kobayashi
- Microbiology, Department of Biopharmaceutical Sciences, Gifu Pharmaceutical University, Gifu, Japan
| | - Tsuyoshi Sugiyama
- Microbiology, Department of Biopharmaceutical Sciences, Gifu Pharmaceutical University, Gifu, Japan
| | - Kouji Umeda
- Immunology Research Institute, GHEN Corporation, Gifu, Japan
| | - Takeshi Shimizu
- Department of Molecular Infectiology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Takao Tsuji
- Department of Microbiology, School of Medicine, Fujita Health University, Aichi, Japan
| | | | - Keiji Oguma
- Department of Bacteriology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Hiroshi Mori
- Microbiology, Department of Biopharmaceutical Sciences, Gifu Pharmaceutical University, Gifu, Japan
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14
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Single chain variable fragment antibodies against Shiga toxins isolated from a human antibody phage display library. Vaccine 2011; 29:5340-6. [DOI: 10.1016/j.vaccine.2011.05.093] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Revised: 05/23/2011] [Accepted: 05/25/2011] [Indexed: 11/22/2022]
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15
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Shimizu T. [Expression and extracellular release of Shiga toxin in enterohemorrahgic Escherichia coli]. Nihon Saikingaku Zasshi 2010; 65:297-308. [PMID: 20505269 DOI: 10.3412/jsb.65.297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Affiliation(s)
- Takeshi Shimizu
- Department of Molecular Infectiology, Graduate School of Medicine, Chiba University, Chuo-ku, Chiba
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Shiga toxin 2 is specifically released from bacterial cells by two different mechanisms. Infect Immun 2009; 77:2813-23. [PMID: 19380474 DOI: 10.1128/iai.00060-09] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Shiga toxin 1 (Stx1) is located in the periplasmic fraction, while Stx2 is found in the extracellular fraction, suggesting that enterohemorrhagic Escherichia coli (EHEC) contains a specific Stx2 release system. Both stx(1) and stx(2) are found within the late operons of Stx-encoding phages. Stx2 production is greatly induced by mitomycin C, suggesting that stx(2) can transcribe from the late phage promoter of the Stx2-encoding phage. However, the Stx1 promoter adjacent to stx(1) is a dominant regulatory element in Stx1 production. With the deletion of phage lysis genes of the Stx2-encoding phage, Stx2 remains in the bacterial cells. Further, we demonstrate that the Stx2-encoding phage, but not the Stx1-encoding phage, is spontaneously induced at extremely low rates. These results indicate that spontaneously specific Stx2-encoding phage induction is involved in specific Stx2 release from bacterial cells. Furthermore, to examine whether another system for specific Stx2 release is present in EHEC, we analyze the stx-replaced mutants. As expected, Stx2 derived from the Stx1 promoter is located in both the extracellular and cell-associated fractions, while mutant Stx2 (B subunit, S31N) derived from the Stx1 promoter is found only in the cell-associated fraction. These results indicate that EHEC has another Stx2 release system that strictly recognizes the serine 31 residue of the B subunit. Overall, we present evidence that specific Stx2 release from bacterial cells is involved in both the Stx2-encoding phage induction system and another Stx2 release system.
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Tsuji T, Shimizu T, Sasaki K, Tsukamoto K, Arimitsu H, Ochi S, Shimizu T, Taniguchi K, Noda M, Neri P, Mori H. A nasal vaccine comprising B-subunit derivative of Shiga toxin 2 for cross-protection against Shiga toxin types 1 and 2. Vaccine 2008; 26:2092-9. [DOI: 10.1016/j.vaccine.2008.02.034] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2007] [Revised: 01/17/2008] [Accepted: 02/19/2008] [Indexed: 11/15/2022]
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Tsuji T, Shimizu T, Sasaki K, Shimizu Y, Tsukamoto K, Arimitsu H, Ochi S, Sugiyama S, Taniguchi K, Neri P, Mori H. Protection of mice from Shiga toxin-2 toxemia by mucosal vaccine of Shiga toxin 2B-His with Escherichia coli enterotoxin. Vaccine 2008; 26:469-76. [DOI: 10.1016/j.vaccine.2007.11.038] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2007] [Revised: 11/14/2007] [Accepted: 11/18/2007] [Indexed: 10/22/2022]
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Shimizu T, Sato T, Kawakami S, Ohta T, Noda M, Hamabata T. Receptor affinity, stability and binding mode of Shiga toxins are determinants of toxicity. Microb Pathog 2007; 43:88-95. [PMID: 17532600 DOI: 10.1016/j.micpath.2007.04.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2006] [Accepted: 04/02/2007] [Indexed: 11/17/2022]
Abstract
The closely related Shiga toxins, Shiga toxin 1 (Stx1) and Shiga toxin 2 (Stx2), can bind to Gb3 receptors. However, Stx2-producing enterohemorrhagic Escherichia coli (EHEC) strains are more commonly associated with serious human disease (viz., hemolytic-uremic syndrome) than Stx1-producing strains. To clarify the relationship between properties and toxicity of these toxins, we constructed and analyzed a hybrid holotoxin composed of Stx2A and Stx1B, designated as Stx2A1B, and a B subunit chimeric holotoxin composed of Stx2A and Stx2B (III V), designated as Stx2A2B (III V). The affinity of Stx2A1B to Gb3 was lower than that of Stx1, higher than that of Stx2 and identical to that of Stx2A2B (III V). On the other hand, the 50% lethal dose (LD(50)) for mice of Stx2A1B was lower than that of Stx1, but higher than that of Stx2. These results suggested that pathogenicity in mice was inversely related to the receptor affinity of the holotoxins. However, LD(50) of Stx2A1B was not identical to that of Stx2A2B (III V). Gel filtration analysis indicated that Stx2A2B (III V) was relatively less stable than Stx2A1B. Moreover, cross-linking experiments demonstrated that the modes of cell surface binding of Stx2A2B (III V) and Stx2A1B were different. These results indicated that the receptor affinity, stability and binding mode of Shiga toxins might be important determinants for toxicity in mice.
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Affiliation(s)
- Takeshi Shimizu
- Department of Molecular Infectiology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chiba 260-8670, Japan.
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