<i>Clostridium difficile</i>Toxin A Carboxyl-Terminus Peptide Lacking ADP-Ribosyltransferase Activity Acts as a Mucosal Adjuvant

Castagliuolo, Ignazio; Sardina, Marina; Brun, Paola; DeRos, Chiara; Mastrotto, Cristina; Lovato, Laura; Palù, Giorgio

doi:10.1128/iai.72.5.2827-2836.2004

Cited by 24 publications

(32 citation statements)

References 53 publications

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“…Mice that were transcutaneously immunized with CT and CDA developed more prominent anti-CT IgA responses in serum and stool than mice that were transcutaneously immunized with CT alone. These observations and our detection of anti-C. difficile toxin A responses following TCI with CDA alone may reflect immunoadjuvantative properties of the carboxyl terminus of C. difficile toxin A itself (7).…”

Section: Discussionmentioning

confidence: 74%

Transcutaneous Immunization withClostridium difficileToxoid A Induces Systemic and Mucosal Immune Responses and Toxin A-Neutralizing Antibodies in Mice

et al. 2007

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Section: Discussionmentioning

confidence: 74%

Transcutaneous Immunization withClostridium difficileToxoid A Induces Systemic and Mucosal Immune Responses and Toxin A-Neutralizing Antibodies in Mice

et al. 2007

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“…Because of the insufficient cross-protection elicited by the individual antitoxins, we sought to generate a single immunogen capable of inducing potent neutralizing antibodies against both toxins. The RBD is the immunodominant toxin region of TcdA and possesses potent adjuvant activity due to its lectin-like structural repeats (6,57). In contrast, the neutralizing epitopes in TcdB are primarily confined to the N terminus since preincubation of polysera from aTcdB-immunized mice with recombinant TcdB-RBD did not significantly reduce the serum neutralizing activity (Fig.…”

Section: Resultsmentioning

confidence: 99%

A Chimeric Toxin Vaccine Protects against Primary and Recurrent Clostridium difficile Infection

et al. 2012

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fThe global emergence of Clostridium difficile infection (CDI) has contributed to the recent surge in severe antibiotic-associated diarrhea and colonic inflammation. C. difficile produces two homologous glucosylating exotoxins, TcdA and TcdB, both of which are pathogenic and require neutralization to prevent disease occurrence. However, because of their large size and complex multifunctional domain structures, it has been a challenge to produce native recombinant toxins that may serve as vaccine candidates. Here, we describe a novel chimeric toxin vaccine that retains major neutralizing epitopes from both toxins and confers complete protection against primary and recurrent CDI in mice. Using a nonpathogenic Bacillus megaterium expression system, we generated glucosyltransferase-deficient holotoxins and demonstrated their loss of toxicity. The atoxic holotoxins induced potent antitoxin neutralizing antibodies showing little cross-immunogenicity or protection between TcdA and TcdB. To facilitate simultaneous protection against both toxins, we generated an active clostridial toxin chimera by switching the receptor binding domain of TcdB with that of TcdA. The toxin chimera was fully cytotoxic and showed potent proinflammatory activities. This toxicity was essentially abolished in a glucosyltransferase-deficient toxin chimera, cTxAB. Parenteral immunization of mice or hamsters with cTxAB induced rapid and potent neutralizing antibodies against both toxins. Complete and long-lasting disease protection was conferred by cTxAB vaccinations against both laboratory and hypervirulent C. difficile strains. Finally, prophylactic cTxAB vaccination prevented spore-induced disease relapse, which constitutes one of the most significant clinical issues in CDI. Thus, the rational design of recombinant chimeric toxins provides a novel approach for protecting individuals at high risk of developing CDI.

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“…Carbohydrate-binding assays indicated that the rARU of TcdA can preferentially recognize 3ЈHSO 3 -containing oligosaccharides of diverse structures. The biological activation of endothelial cells by the TcdA CRD on endothelial cells and the subsequent induction of leukocyte chemotaxis might also be the underlying mechanism that partially accounts for the potential adjuvant effect of this repeat peptide in vivo (4,31). This TcdA CRD, as the modulin, might also play a key role in the inflammatory response by which the toxin causes tissue damage.…”

Section: Discussionmentioning

confidence: 99%

“…Unlike for other repeats, little is known about the biological functions of CROPs. Besides carbohydrate-binding activity, the TcdA CRD has an immune modulating effect when used as an adjuvant or carrier protein for mucosal immunization (4,31). Nevertheless, conflicting results have been ob-tained from in vitro studies of the biological activity of the CRD of TcdA alone in different cell culture systems: activation signals were detected in epithelial cells (33), but no activation was observed for monocytes (16).…”

mentioning

confidence: 99%

C-Terminal Repeats ofClostridium difficileToxin A Induce Production of Chemokine and Adhesion Molecules in Endothelial Cells and Promote Migration of Leukocytes

et al. 2008

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The C-terminal repeating sequences of Clostridium difficile toxin A (designated ARU) are homologous to the carbohydrate-binding domain of streptococcal glucosyltransferases (GTFs) that were recently identified as potent modulins. To test the hypothesis that ARU might exert a similar biological activity on endothelial cells, recombinant ARU (rARU), which was noncytotoxic to cell cultures, was analyzed using human umbilical vein endothelial cells. The rARU could bind directly to endothelial cells in a serum-and calcium-dependent manner and induce the production of interleukin-6 (IL-6), IL-8, and monocyte chemoattractant protein 1 in a dosedependent manner. An oligosaccharide binding assay indicated that rARU, but not GTFC, binds preferentially to Lewis antigens and 3HSO 3 -containing oligosaccharides. Binding of rARU to human endothelial or intestinal cells correlated directly with the expression of Lewis Y antigen. Bound rARU directly activated mitogenactivated protein kinases and the NF-B signaling pathway in endothelial cells to release biologically active chemokines and adhesion molecules that promoted migration in a transwell assay and the adherence of polymorphonuclear and mononuclear cells to the endothelial cells. These results suggest that ARU may bind to multiple carbohydrate motifs to exert its biological activity on human endothelial cells.

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Clostridium difficileToxin A Carboxyl-Terminus Peptide Lacking ADP-Ribosyltransferase Activity Acts as a Mucosal Adjuvant

Cited by 24 publications

References 53 publications

Transcutaneous Immunization withClostridium difficileToxoid A Induces Systemic and Mucosal Immune Responses and Toxin A-Neutralizing Antibodies in Mice

Transcutaneous Immunization withClostridium difficileToxoid A Induces Systemic and Mucosal Immune Responses and Toxin A-Neutralizing Antibodies in Mice

A Chimeric Toxin Vaccine Protects against Primary and Recurrent Clostridium difficile Infection

C-Terminal Repeats ofClostridium difficileToxin A Induce Production of Chemokine and Adhesion Molecules in Endothelial Cells and Promote Migration of Leukocytes

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