Related Experiment Video
Updated: Aug 24, 2026

Adjuvant Activity of Mycobacterium paratuberculosis in Enhancing the Immunogenicity of Autoantigens During Experimental Autoimmune Encephalomyelitis
Published on: May 12, 2023
Clostridium difficile toxin A carboxyl-terminus peptide lacking ADP-ribosyltransferase activity acts as a mucosal
Ignazio Castagliuolo1, Marina Sardina, Paola Brun
1Department of Histology, Microbiology and Medical Biotechnologies, University of Padua, Padua, Italy.
Abstract:
The receptor binding domains of the most potent mucosal adjuvants, bacterial toxins and plant lectins, are organized in repeat units to recognize specific sugar residues. The lectin-like structure of the C-terminal region of Clostridium difficile toxin A prompted us to investigate the mucosal adjuvant properties of a nontoxigenic peptide corresponding to amino acids 2394 to 2706 (TxA(C314)). We compared TxA(C314) adjuvant activity to those of cholera toxin (CT) and Escherichia coli heat-labile enterotoxin subunit B (EtxB) coadministered orally or nasotracheally with poor peptide antigens (keyhole limpet hemocyanin [KLH] and hen egg lysozyme [HEL]). Levels of anti-KLH-specific serum immunoglobulin G (IgG) and IgA as well as that of mucosal IgA were significantly higher in animals immunized orally with TxA(C314) plus KLH than with KLH alone, CT plus KLH, or EtxB plus KLH. Following intranasal immunization with TxA(C314) plus HEL, levels of serum- and mucosa-specific antibodies were comparable to those induced by coadministering HEL with CT or EtxB. The TxA(C314) adjuvant effect following oral, but not intranasal, immunization was dose dependent. The analysis of the subclasses of anti-KLH-specific IgG isotypes and the cytokines released from splenocytes of immunized mice challenged in vitro with KLH indicates the induction of a mixed Th1/Th2-type immune response, with prevalence of the Th1 branch. We conclude that TxA(C314) enhances immune responses against mucosa-coadministered foreign antigens and represents a promising mucosal adjuvant, especially because its ability to stimulate mixed Th1/Th2 responses with a strong a Th1 component is extremely worthwhile against intracellular pathogens.
More Related Videos
09:12A Protein Microarray Assay for Serological Determination of Antigen-specific Antibody Responses Following Clostridium difficile Infection
Published on: June 15, 2018
13:34Production, Crystallization and Structure Determination of C. difficile PPEP-1 via Microseeding and Zinc-SAD
Published on: December 30, 2016
Related Concept Videos
Bacterial Toxins
Botulism
Diphtheria
GPCRs Regulate Adenylyl Cylase Activity
Two...
Bacterial Gastroenteritis
Inflammatory Bowel Disease III: Crohn's Disease