title: Enhancement of the cytotoxic activity of Clostridium difficile toxin A by surface-associated antigens.
abstract: Cell-surface antigens of Clostridium difficile and LPS from Escherichia coli were investigated for modulating effects on the activity of C. difficile toxin A on Vero and Caco2 cells. The antigens of C. difficile tested comprised: (i) an EDTA extract, which contained several major and minor cell-surface proteins and the membrane-associated lipocarbohydrate (LC); (ii) a guanidine hydrochloride extract, which mainly contained the surface-layer proteins; (iii) an aqueous phenol-extracted, protein-free LC. On their own, none of the antigens had a detrimental effect on the cells, with the EDTA extract and LC having a marginally protective effect. When these antigens were added to suboptimal levels of toxin A, there was significant enhancement of its cytotoxicity by the EDTA and LC preparations on both cell types. LPS showed some enhancement of the effect of toxin on Vero cells at the lowest levels of toxin investigated. It was concluded that this effect seen in vitro may have a role to play in the colon during infection with C. difficile.
authors.affiliation: Centre for Infectious Diseases, University of Edinburgh College of Medicine and Veterinary Medicine, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB, UK.
authors.forename: Karla
authors.initials: K
authors.lastname: Sánchez-Hurtado
authors.affiliation: Centre for Infectious Diseases, University of Edinburgh College of Medicine and Veterinary Medicine, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB, UK.
authors.forename: Ian R
authors.initials: IR
authors.lastname: Poxton
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000633:toxicity*; D000954:Antigens, Surface / Q000633:toxicity*; D001427:Bacterial Toxins / Q000633:toxicity*; D018938:Caco-2 Cells; D002470:Cell Survival / Q000187:drug effects*; D002522:Chlorocebus aethiops; D004768:Enterotoxins / Q000633:toxicity*; D006801:Humans; D014709:Vero Cells
chemical_list: D000942:Antigens, Bacterial; D000954:Antigens, Surface; D001427:Bacterial Toxins; D004768:Enterotoxins; C041348:tcdA protein, Clostridium difficile