title: Local and systemic neutralizing antibody responses induced by intranasal immunization with the nontoxic binding domain of toxin A from Clostridium difficile.
abstract: Fourteen of the 38 C-terminal repeats from Clostridium difficile toxin A (14CDTA) were cloned and expressed either with an N-terminal polyhistidine tag (14CDTA-HIS) or fused to the nontoxic binding domain from tetanus toxin (14CDTA-TETC). The recombinant proteins were successfully purified by bovine thyroglobulin affinity chromatography. Both C. difficile toxin A fusion proteins bound to known toxin A ligands present on the surface of rabbit erythrocytes. Intranasal immunization of BALB/c mice with three separate 10-microg doses of 14CDTA-HIS or -TETC generated significant levels of anti-toxin A serum antibodies compared to control animals. The coadministration of the mucosal adjuvant heat labile toxin (LT) from Escherichia coli (1 microg) significantly increased the anti-toxin A response in the serum and at the mucosal surface. Importantly, the local and systemic antibodies generated neutralized toxin A cytotoxicity. Impressive systemic and mucosal anti-toxin A responses were also seen following coadministration of 14CDTA-TETC with LTR72, an LT derivative with reduced toxicity which shows potential as a mucosal adjuvant for humans.
authors.affiliation: Microbial Pathogenicity Research Group, Department of Microbiology, St. Bartholomew's and the Royal London School of Medicine and Dentistry, West Smithfield, London ECIA 7BE, United Kingdom.
authors.forename: S J
authors.initials: SJ
authors.lastname: Ward
authors.forename: G
authors.initials: G
authors.lastname: Douce
authors.forename: G
authors.initials: G
authors.lastname: Dougan
authors.forename: B W
authors.initials: BW
authors.lastname: Wren
mesh_terms: D000281:Administration, Intranasal; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis*; D001427:Bacterial Toxins; D016466:CHO Cells; D016360:Clostridioides difficile / Q000276:immunology*; D006224:Cricetinae; D004768:Enterotoxins / Q000008:administration & dosage / Q000276:immunology*; D005260:Female; D006384:Hemagglutination; D007114:Immunization; D007071:Immunoglobulin A, Secretory / Q000096:biosynthesis; D051379:Mice; D008807:Mice, Inbred BALB C; D010446:Peptide Fragments / Q000276:immunology*; D011817:Rabbits; D011994:Recombinant Proteins / Q000276:immunology; D013744:Tetanus Toxin / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D001427:Bacterial Toxins; D004768:Enterotoxins; D007071:Immunoglobulin A, Secretory; D010446:Peptide Fragments; D011994:Recombinant Proteins; D013744:Tetanus Toxin; C041348:tcdA protein, Clostridium difficile