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Shrestha A, Mehdizadeh Gohari I, Li J, Navarro M, Uzal FA, McClane BA. The biology and pathogenicity of Clostridium perfringens type F: a common human enteropathogen with a new(ish) name. Microbiol Mol Biol Rev 2024; 88:e0014023. [PMID: 38864615 PMCID: PMC11426027 DOI: 10.1128/mmbr.00140-23] [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] [Indexed: 06/13/2024] Open
Abstract
SUMMARYIn the 2018-revised Clostridium perfringens typing classification system, isolates carrying the enterotoxin (cpe) and alpha toxin genes but no other typing toxin genes are now designated as type F. Type F isolates cause food poisoning and nonfoodborne human gastrointestinal (GI) diseases, which most commonly involve type F isolates carrying, respectivefooly, a chromosomal or plasmid-borne cpe gene. Compared to spores of other C. perfringens isolates, spores of type F chromosomal cpe isolates often exhibit greater resistance to food environment stresses, likely facilitating their survival in improperly prepared or stored foods. Multiple factors contribute to this spore resistance phenotype, including the production of a variant small acid-soluble protein-4. The pathogenicity of type F isolates involves sporulation-dependent C. perfringens enterotoxin (CPE) production. C. perfringens sporulation is initiated by orphan histidine kinases and sporulation-associated sigma factors that drive cpe transcription. CPE-induced cytotoxicity starts when CPE binds to claudin receptors to form a small complex (which also includes nonreceptor claudins). Approximately six small complexes oligomerize on the host cell plasma membrane surface to form a prepore. CPE molecules in that prepore apparently extend β-hairpin loops to form a β-barrel pore, allowing a Ca2+ influx that activates calpain. With low-dose CPE treatment, caspase-3-dependent apoptosis develops, while high-CPE dose treatment induces necroptosis. Those effects cause histologic damage along with fluid and electrolyte losses from the colon and small intestine. Sialidases likely contribute to type F disease by enhancing CPE action and, for NanI-producing nonfoodborne human GI disease isolates, increasing intestinal growth and colonization.
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Affiliation(s)
- Archana Shrestha
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Iman Mehdizadeh Gohari
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Jihong Li
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Mauricio Navarro
- Instituto de Patologia Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Francisco A Uzal
- California Animal Health and Food Safety Laboratory System, School of Veterinary Medicine, University of California Davis, San Bernardino, California, USA
| | - Bruce A McClane
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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Abstract
C. perfringens type F strains are a common cause of food poisoning and antibiotic-associated diarrhea. Type F strain virulence requires production of C. perfringens enterotoxin (CPE). In Caco-2 cells, high CPE concentrations cause necrosis while low enterotoxin concentrations induce apoptosis. The current study determined that receptor-interacting serine/threonine-protein kinases 1 and 3 are involved in both CPE-induced apoptosis and necrosis in Caco-2 cells, while mixed-lineage kinase domain-like pseudokinase (MLKL) oligomerization is involved in CPE-induced necrosis, thereby indicating that this form of CPE-induced cell death involves necroptosis. High CPE concentrations also caused necroptosis in T84 and Vero cells. Calpain activation was identified as a key intermediate for CPE-induced necroptosis. These results suggest inhibitors of RIP1, RIP3, MLKL oligomerization, or calpain are useful therapeutics against CPE-mediated diseases. Clostridium perfringens type F strains cause gastrointestinal disease when they produce a pore-forming toxin named C. perfringens enterotoxin (CPE). In human enterocyte-like Caco-2 cells, low CPE concentrations cause caspase-3-dependent apoptosis, while high CPE concentrations cause necrosis. Since necrosis or apoptosis sometimes involves receptor-interacting serine/threonine-protein kinase-1 or 3 (RIP1 or RIP3), this study examined whether those kinases are important for CPE-induced apoptosis or necrosis. Highly specific RIP1 or RIP3 inhibitors reduced both CPE-induced apoptosis and necrosis in Caco-2 cells. Those findings suggested that the form of necrosis induced by treating Caco-2 cells with high CPE concentrations involves necroptosis, which was confirmed when high, but not low, CPE concentrations were shown to induce oligomerization of mixed-lineage kinase domain-like pseudokinase (MLKL), a key late step in necroptosis. Furthermore, an MLKL oligomerization inhibitor reduced cell death caused by high, but not low, CPE concentrations. Supporting RIP1 and RIP3 involvement in CPE-induced necroptosis, inhibitors of those kinases also reduced MLKL oligomerization during treatment with high CPE concentrations. Calpain inhibitors similarly blocked MLKL oligomerization induced by high CPE concentrations, implicating calpain activation as a key intermediate in initiating CPE-induced necroptosis. In two other CPE-sensitive cell lines, i.e., Vero cells and human enterocyte-like T84 cells, low CPE concentrations also caused primarily apoptosis/late apoptosis, while high CPE concentrations mainly induced necroptosis. Collectively, these results establish that high, but not low, CPE concentrations cause necroptosis and suggest that RIP1, RIP3, MLKL, or calpain inhibitors can be explored as potential therapeutics against CPE effects in vivo.
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Chakrabarti G, Zhou X, McClane BA. Death pathways activated in CaCo-2 cells by Clostridium perfringens enterotoxin. Infect Immun 2003; 71:4260-70. [PMID: 12874301 PMCID: PMC166005 DOI: 10.1128/iai.71.8.4260-4270.2003] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Clostridium perfringens enterotoxin (CPE), a 35-kDa polypeptide, induces cytotoxic effects in the enterocyte-like CaCo-2 cell culture model. To identify the mammalian cell death pathway(s) mediating CPE-induced cell death, CaCo-2 cultures were treated with either 1 or 10 micro g of CPE per ml. Both CPE doses were found to induce morphological damage and DNA cleavage in CaCo-2 cells. The oncosis inhibitor glycine, but not a broad-spectrum caspase inhibitor, was able to transiently block both of those pathological effects in CaCo-2 cells treated with the higher, but not the lower, CPE dose. Conversely, a caspase 3/7 inhibitor (but not glycine or a caspase 1 inhibitor) blocked morphological damage and DNA cleavage in CaCo-2 cells treated with the lower, but not the higher, CPE dose. Collectively, these results indicate that lower CPE doses cause caspase 3/7-dependent apoptosis, while higher CPE doses induce oncosis. Apoptosis caused by the lower CPE dose was shown to proceed via a classical pathway involving mitochondrial membrane depolarization and cytochrome c release. As the CPE concentrations used in this study for demonstrating apoptosis and oncosis have pathophysiologic relevance, these results suggest that both oncosis and apoptosis may occur in the intestines during CPE-associated gastrointestinal disease.
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Affiliation(s)
- Ganes Chakrabarti
- Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA
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McClane BA. The complex interactions between Clostridium perfringens enterotoxin and epithelial tight junctions. Toxicon 2001; 39:1781-91. [PMID: 11595640 DOI: 10.1016/s0041-0101(01)00164-7] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Clostridium perfringens enterotoxin (CPE) is responsible for the diarrheal symptoms of C. perfringens type A food poisoning and antibiotic-associated diarrhea. The CPE protein consists of a single 35 kDa polypeptide with a C-terminal receptor-binding region and an N-terminal toxicity domain. Under appropriate conditions, CPE can interact with structural components of the epithelial tight junctions, including certain claudins and occludin. Those interactions can affect tight junction structure and function, thereby altering paracellular permeability and (possibly) contributing to CPE-induced diarrhea. However, the tight junction effects of CPE require cellular damage as a prerequisite. CPE induces cellular damage via its cytotoxic activity, which results from plasma membrane permeability alterations caused by formation of a approximately 155 kDa CPE-containing complex that may correspond to a pore. Thus, CPE appears to be a bifunctional toxin that first induces plasma membrane permeability alterations; using the resultant cell damage, CPE then gains access to tight junction proteins and affects tight junction structure and function.
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Affiliation(s)
- B A McClane
- Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, E1240 Biomedical Science Tower, Pittsburgh, PA 15261-2072, USA.
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Singh U, Mitic LL, Wieckowski EU, Anderson JM, McClane BA. Comparative biochemical and immunocytochemical studies reveal differences in the effects of Clostridium perfringens enterotoxin on polarized CaCo-2 cells versus Vero cells. J Biol Chem 2001; 276:33402-12. [PMID: 11445574 DOI: 10.1074/jbc.m104200200] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Since most in vitro studies exploring the action of Clostridium perfringens enterotoxin (CPE) utilize either Vero or CaCo-2 cells, the current study directly compared the CPE responsiveness of those two cell lines. When CPE-treated in suspension, both CaCo-2 and Vero cells formed SDS-resistant, CPE-containing complexes of approximately 135, approximately 155, and approximately 200 kDa. However, confluent Transwell cultures of either cell line CPE-treated for 20 min formed only the approximately 155-kDa complex. Since those Transwell cultures also exhibited significant (86)Rb release, approximately 155-kDa complex formation is sufficient for CPE-induced cytotoxicity. Several differences in CPE responsiveness between the two cell lines were also detected. (i) CaCo-2 cells were more sensitive when CPE-treated on their basal surface, whereas Vero cells were more sensitive when CPE-treated on their apical surface; those sensitivity differences correlated with CPE binding the apical versus basolateral surfaces of these two cell lines. (ii) CPE-treated Vero cells released (86)Rb into both Transwell chambers, whereas CaCo-2 cells released (86)Rb only into the CPE-containing Transwell chamber. (iii) Vero cells express the tight junction (TJ) protein occludin but (unlike CaCo-2 cells) cannot form TJs. The ability of TJs to affect CPE responsiveness is supported by the similar effects of CPE on Transwell cultures of CaCo-2 cells and Madin-Darby canine kidney cells, another polarized cell forming TJs. Confluent CaCo-2 Transwell cultures CPE-treated for >1 h formed the approximately 200-kDa CPE complex (which also contains occludin), exhibited morphologic damage, and had occludin removed from their TJs. Collectively, these results identify CPE as a bifunctional toxin that, in confluent polarized cells, first exerts a cytotoxic effect mediated by the approximately 155-kDa complex. Resultant damage then provides CPE access to TJs, leading to approximately 200-kDa complex formation, internalization of some TJ proteins, and TJ damage that may increase paracellular permeability and thereby contribute to the diarrhea of CPE-induced gastrointestinal disease.
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Affiliation(s)
- U Singh
- Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA
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Kokai-Kun JF, Benton K, Wieckowski EU, McClane BA. Identification of a Clostridium perfringens enterotoxin region required for large complex formation and cytotoxicity by random mutagenesis. Infect Immun 1999; 67:5634-41. [PMID: 10531210 PMCID: PMC96936 DOI: 10.1128/iai.67.11.5634-5641.1999] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Clostridium perfringens enterotoxin (CPE), a single polypeptide of 319 amino acids, has a unique multistep mechanism of action. In the first step, CPE binds to claudin proteins and/or a 50-kDa eukaryotic membrane protein receptor, forming a small ( approximately 90-kDa) complex. This small complex apparently then associates with a 70-kDa eukaryotic membrane protein, resulting in formation of a large complex that induces the onset of membrane permeability alterations. To better define the boundaries of CPE functional regions and to identify specific amino acid residues involved in various steps of CPE action, in this study we subjected the cloned cpe gene to random mutagenesis in XL-1 Red strains of Escherichia coli. Seven CPE random mutants with reduced cytotoxicity for Vero cells were phenotypically characterized for the ability to complete each step in CPE action. Five of these seven recombinant CPE (rCPE) random mutants (G49D, S59L, R116S, R137G, and S167P) exhibited binding characteristics similar to those of rCPE or native CPE, while the Y310C and W226Stop mutants showed reduced binding and no binding, respectively, to brush border membranes. Interestingly, two completely nontoxic mutants (G49D and S59L) were able to bind and form small complex but they did not mediate any detectable large complex formation. Another strongly attenuated mutant, R116S, formed reduced amounts of an anomalously migrating large complex. Collectively, these results provide further support for large complex formation being an essential step in CPE action and also identify the CPE region ranging from residues approximately 45 to 116 as important for large complex formation. Finally, we also report that limited removal of extreme N-terminal CPE sequences, which may occur in vivo during disease, stimulates cytotoxic activity by enhancing large complex formation.
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Affiliation(s)
- J F Kokai-Kun
- Department of Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA
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7
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Abstract
To further our knowledge of the structure-function relationship and mechanism of action of the Clostridium perfringens enterotoxin (CPE), a series of recombinant CPE (rCPE) species containing N- and C-terminal CPE deletion fragments was constructed by recombinant DNA approaches. Each rCPE species was characterized for its ability to complete the first four early steps in the action of CPE, putatively ordered as specific binding, a postbinding physical change to bound CPE, large-complex formation, and induction of alterations in small-molecule membrane permeability. These studies demonstrated that (i) at least 44 amino acids can be removed from the N terminus of CPE without loss of cytotoxicity, (ii) removal of the first 53 amino acids from the N terminus of CPE produces a fragment that appears to be noncytotoxic because it cannot undergo the post-binding physical change step in CPE action, (iii) removal of as few as five amino acids from the C terminus of CPE produces a noncytotoxic fragment lacking receptor binding activity, and (iv) a fragment lacking the first 44 N-terminal amino acids of native CPE formed twice as much large complex and was twice as cytotoxic as native CPE. From these structure-function results, it appears that the minimum-size cytotoxic CPE fragment comprises approximately residues 45 to 319 of native CPE. Results from these deletion fragment studies have also contributed to our understanding of CPE action by (i) independently supporting previous suggestions that binding, the postbinding physical change step, and large-complex formation represent important steps in CPE cytotoxicity and (ii) providing independent evidence confirming the putative sequential order of these early events in CPE action.
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Affiliation(s)
- J F Kokai-Kun
- Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pennsylvania 15261, USA
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Meer RR, Songer JG, Park DL. Human disease associated with Clostridium perfringens enterotoxin. REVIEWS OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 1997; 150:75-94. [PMID: 8978214 DOI: 10.1007/978-1-4612-2278-1_3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Clostridium perfringens continues to be a common cause of food-borne disease. Characteristics of this organism that contribute to its ability to cause food-borne illness include the formation of heat-resistant spores that survive normal cooking/heating temperatures, a rapid growth rate in warm food, and the production of enterotoxin (CPE) in the human gut. Time and temperature abuse associated with food preparation contributes to the majority of outbreaks of C. perfringens food-borne disease. CPE-induced diarrhea has been reported in the absence of a defined food vehicle. These cases have been typically associated with the elderly and following a course of antibiotic therapy. The incidence of CPE-induced diarrhea may be expected to increase with the growing population of immunocompromised (disease-, treatment-, or age-induced) individuals. Clostridium perfringens has been implicated as a possible contributor to the development of SIDS in susceptible individuals. Specifically, it has been hypothesized that CPE acts as a triggering agent, initiating the events associated with the development of SIDS. Continued refinement of both immunoassays and molecular methods for toxin and gene detection, respectively, will facilitate their eventual availability as commercial kits, providing rapid and simplified methods for the detection of C. perfringens isolates that produce or have the capacity to produce CPE as well as other toxins associated with this organism.
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Affiliation(s)
- R R Meer
- Department of Veterinary Science, University of Arizona, Tucson 85721, USA
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Affiliation(s)
- J G Songer
- Department of Veterinary Science, University of Arizona, Tucson 85721, USA.
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10
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Kokai-Kun JF, McClane BA. Evidence that a region(s) of the Clostridium perfringens enterotoxin molecule remains exposed on the external surface of the mammalian plasma membrane when the toxin is sequestered in small or large complexes. Infect Immun 1996; 64:1020-5. [PMID: 8641752 PMCID: PMC173873 DOI: 10.1128/iai.64.3.1020-1025.1996] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
In studies performed to investigate the topology of Clostridium perfringens enterotoxin (CPE) when this toxin is associated with intestinal brush border membrane (BBMs), it was shown that radiolabeled CPE antibodies react more strongly against intact CPE-treated BBMs than against control BBMs. Immunoprecipitation studies then demonstrated that CPE antibodies are able to react with both small and large CPE-containing complexes while these complexes are still present in intact BBMs. Therefore, at least a portion of the CPE molecule appears to remain surface exposed in BBMs throughout the action of this toxin.
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Affiliation(s)
- J F Kokai-Kun
- Department of Molecular Genetics and Biochemistry, School of Medicine, University of Pittsburgh, Pennsylvania 15261, USA
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11
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Melville SB, Labbe R, Sonenshein AL. Expression from the Clostridium perfringens cpe promoter in C. perfringens and Bacillus subtilis. Infect Immun 1994; 62:5550-8. [PMID: 7960138 PMCID: PMC303301 DOI: 10.1128/iai.62.12.5550-5558.1994] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Clostridium perfringens is a source of food poisoning in humans and animals because of production of a potent enterotoxin (CPE). To study the regulation of the cpe gene in C. perfringens, we cloned and sequenced the cpe promoter regions and N-terminal domains from three strains. The cpe promoter region from one strain contained a 45-bp insertion compared with previously published sequences. This insertion was also found in two (of five) other Cpe+ strains. cpe gene expression in C. perfringens was measured by using translational fusions of each promoter type to the Escherichia coli gusA gene, which codes for beta-glucuronidase. For either promoter type, cpe-gusA expression was undetectable throughout exponential growth but increased dramatically at the beginning of the stationary phase. To measure cpe expression in Bacillus subtilis, cpe-gusA fusions were integrated into the B. subtilis chromosome. Both types of promoter exhibited moderate expression during exponential growth; cpe expression increased threefold at the beginning of the stationary phase. Transcriptional start sites were determined by primer extension and in vitro transcription assays. For C. perfringens, both types of promoter gave the same 5' end, 197 bp upstream of the translation start (50 bp downstream of the 45-bp insertion). In B. subtilis, however, the 5' end was internal to the 45-bp insertion, suggesting the use of a different promoter than that utilized by C. perfringens.
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Affiliation(s)
- S B Melville
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111
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12
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Wieckowski E, Wnek A, McClane B. Evidence that an approximately 50-kDa mammalian plasma membrane protein with receptor-like properties mediates the amphiphilicity of specifically bound Clostridium perfringens enterotoxin. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)34135-2] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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McClane BA. Clostridium perfringens enterotoxin acts by producing small molecule permeability alterations in plasma membranes. Toxicology 1994; 87:43-67. [PMID: 8160188 DOI: 10.1016/0300-483x(94)90154-6] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Clostridium perfringens enterotoxin (CPE) appears to utilize a unique mechanism of action to directly affect the plasma membrane permeability of mammalian cells. CPE action involves a multi-step action which culminates in cytotoxicity. Initially CPE binds to a protein receptor on mammalian plasma membranes. The membrane-bound CPE then becomes progressively more resistant to release by proteases (a phenomenon consistent with the insertion of CPE into membranes). This 'inserted' CPE then participates in the formation of a large complex in plasma membranes which contains one CPE: one 70 kDa membrane protein: one 50 kDa membrane protein. Upon formation of large complex, plasma membranes become freely permeable to small molecules such as ions and amino acids. This CPE-induced disruption of the cellular colloid-osmotic equilibrium then causes secondary cellular effects and cell death.
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Affiliation(s)
- B A McClane
- Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, PA 15261
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14
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Czeczulin JR, Hanna PC, McClane BA. Cloning, nucleotide sequencing, and expression of the Clostridium perfringens enterotoxin gene in Escherichia coli. Infect Immun 1993; 61:3429-39. [PMID: 8335373 PMCID: PMC281020 DOI: 10.1128/iai.61.8.3429-3439.1993] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
A complete copy of the gene (cpe) encoding Clostridium perfringens enterotoxin (CPE), an important virulence factor involved in C. perfringens food poisoning and other gastrointestinal illnesses, has been cloned, sequenced, and expressed in Escherichia coli. The cpe gene was shown to encode a 319-amino-acid polypeptide with a deduced molecular weight of 35,317. There was no consensus sequence for a typical signal peptide present in the 5' region of cpe. Cell lysates from recombinant cpe-positive E. coli were shown by quantitative immunoblot analysis to contain moderate amounts of CPE, and this recombinant CPE was equal to native CPE in cytotoxicity for mammalian Vero cells. CPE expression in recombinant E. coli appeared to be largely driven from a clostridial promoter. Immunoblot analysis also demonstrated very low levels of CPE in vegetative cell lysates of enterotoxin-positive C. perfringens. However, when the same C. perfringens strain was induced to sporulate, much stronger CPE expression was detected in these sporulating cells than in either vegetative C. perfringens cells or recombinant E. coli. Collectively, these results strongly suggest that sporulation is not essential for cpe expression, but sporulation does facilitate high-level cpe expression.
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Affiliation(s)
- J R Czeczulin
- Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pennsylvania 15261-2072
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Mietzner TA, Kokai-Kun JF, Hanna PC, McClane BA. A conjugated synthetic peptide corresponding to the C-terminal region of Clostridium perfringens type A enterotoxin elicits an enterotoxin-neutralizing antibody response in mice. Infect Immun 1992; 60:3947-51. [PMID: 1500207 PMCID: PMC257418 DOI: 10.1128/iai.60.9.3947-3951.1992] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
A synthetic peptide homolog corresponding to the C-terminal 30 amino acids of Clostridium perfringens type A enterotoxin (CPE) was conjugated to a thyroglobulin carrier and used to immunize mice. Conjugate-immunized mice produced antibodies which neutralized native CPE cytotoxicity, at least in part, by blocking enterotoxin binding. This peptide may be useful for the development of a vaccine to protect against CPE-mediated disease.
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Affiliation(s)
- T A Mietzner
- Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pennsylvania 15261-2072
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16
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Hanna PC, Wieckowski EU, Mietzner TA, McClane BA. Mapping of functional regions of Clostridium perfringens type A enterotoxin. Infect Immun 1992; 60:2110-4. [PMID: 1373406 PMCID: PMC257123 DOI: 10.1128/iai.60.5.2110-2114.1992] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Studies were conducted to allow construction of an initial map of the structure-versus-function relationship of the Clostridium perfringens type A enterotoxin (CPE). Removal of the N-terminal 25 amino acids of CPE increased the primary cytotoxic effect of CPE but did not affect binding. CPE sequences required for at least four epitopes were also identified.
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Affiliation(s)
- P C Hanna
- Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pennsylvania 15261-2072
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17
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Bobak DA, Guerrant RL. New developments in enteric bacterial toxins. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 1992; 23:85-108. [PMID: 1540540 DOI: 10.1016/s1054-3589(08)60963-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- D A Bobak
- Department of Medicine, University of Virginia School of Medicine, Charlottesville 22908
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18
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Abstract
Clostridium perfringens is the causative agent of a number of human diseases, such as gas gangrene and food poisoning, and many diseases of animals. Recently significant advances have been made in the development of C. perfringens genetics. Studies on bacteriocin plasmids and conjugative R plasmids have led to the cloning and analysis of many C. perfringens genes and the construction of shuttle plasmids. The relationship of antibiotic resistance genes to similar genes from other bacteria has been elucidated. A detailed physical map of the C. perfringens chromosome has been prepared, and numerous genes have been located on that map. Reproducible transformation methods for the introduction of plasmids into C. perfringens have been developed, and several genes coding for the production of extracellular toxins and enzymes have been cloned. Now that it is possible to freely move genetic information back and forth between C. perfringens and Escherichia coli, it will be possible to apply modern molecular methods to studies on the pathogenesis of C. perfringens infections.
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Affiliation(s)
- J I Rood
- Department of Microbiology, Monash University, Clayton, Victoria, Australia
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Localization of the receptor-binding region of Clostridium perfringens enterotoxin utilizing cloned toxin fragments and synthetic peptides. The 30 C-terminal amino acids define a functional binding region. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)99124-6] [Citation(s) in RCA: 89] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Abstract
Legionella pneumophila is a gram-negative facultative intracellular parasite that causes Legionnaires disease. To explore the interactions between L. pneumophila and host cells, we have developed a continuous cell line model of infection. We show that about 80% of Chinese hamster ovary (CHO) cells were associated with L. pneumophila after incubation for 3 h at a multiplicity of infection of 20 bacteria per cell. Within 3 to 4 h of incubation with L. pneumophila, protein synthesis of CHO cells was markedly inhibited, as shown by the reduction of incorporation of radiolabeled amino acids into proteins. L. pneumophila did not inhibit transport of amino acids or cause degradation of newly synthesized proteins in CHO cells. Cytochalasin D blocked internalization of L. pneumophila by CHO cells, yet CHO cell protein synthesis was inhibited. These results indicated that L. pneumophila could inhibit host protein synthesis from the cell exterior. L. pneumophila that had been killed with antibiotics prior to incubation with CHO cells still inhibited protein synthesis, indicating that the inhibition of CHO cell protein synthesis occurred in the absence of de novo protein synthesis by L. pneumophila.
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Hanna PC, McClane BA. A recombinant C-terminal toxin fragment provides evidence that membrane insertion is important for Clostridium perfringens enterotoxin cytotoxicity. Mol Microbiol 1991; 5:225-30. [PMID: 2014001 DOI: 10.1111/j.1365-2958.1991.tb01843.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Clostridium perfringens enterotoxin (CPE) is believed to be involved in several important gastrointestinal illnesses. Recent studies have identified a number of distinct molecular events which occur after CPE treatment of eukaryotic cells or isolated membranes. Additional studies are underway to determine the temporal order and intrinsic importance of each CPE event for cytotoxicity. We now demonstrate that a truncated CPE fragment binds to membranes, but is unable to insert into membranes or cause any other subsequent post-insertion event. This is the first experimental evidence supporting the importance of membrane insertion for CPE cytotoxicity. Binding of the CPE fragment is also shown to be irreversible, strongly suggesting that the irreversible binding of wild-type CPE is not due solely to insertion of CPE into membranes.
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Affiliation(s)
- P C Hanna
- Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pennsylvania 15261
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McClane BA, Wnek AP. Studies of Clostridium perfringens enterotoxin action at different temperatures demonstrate a correlation between complex formation and cytotoxicity. Infect Immun 1990; 58:3109-15. [PMID: 2117579 PMCID: PMC313618 DOI: 10.1128/iai.58.9.3109-3115.1990] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The cytotoxicity of Clostridium perfringens enterotoxin (CPE) was completely blocked in Vero cells continuously CPE treated at 4 degrees C. [125I]CPE-specific binding to either Vero cells or isolated rabbit intestinal brush border membranes (BBMs) was lower at 4 degrees C than at 24 or 37 degrees C, but reduced enterotoxin binding could not totally explain the loss of cytotoxicity at low temperature. Insertion of enterotoxin into Vero cell membranes or BBMs was temperature independent. However, CPE complex formation (A. P. Wnek and B. A. McClane, Infect. Immun. 57:574-581, 1989) in BBMs and Vero cells was blocked at 4 degrees C. When Vero cells were CPE treated at 4 degrees C, washed to remove unbound toxin, and then shifted to 37 degrees C, complex formation and cytotoxicity were rapidly detected. When CPE binding and complex formation were permitted for 2 min at 37 degrees C, and the Vero cells were then shifted to 4 degrees C, cytotoxicity was detectable at 4 degrees C. These results are consistent with complex formation, rather than complex activity, being the temperature-sensitive step in CPE action which is blocked at 4 degrees C. These studies demonstrate a strong correlation between complex formation and cytotoxicity and are consistent with complex involvement in CPE cytotoxicity. These studies also strongly suggest that CPE insertion precedes both complex formation and induction of small-molecule permeability changes.
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Affiliation(s)
- B A McClane
- Department of Molecular Genetics and Biochemistry, School of Medicine, University of Pittsburgh, Pennsylvania 15261
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