title: Clostridium difficile toxin CDT induces formation of microtubule-based protrusions and increases adherence of bacteria.
abstract: Clostridium difficile causes antibiotic-associated diarrhea and pseudomembranous colitis by production of the Rho GTPase-glucosylating toxins A and B. Recently emerging hypervirulent Clostridium difficile strains additionally produce the binary ADP-ribosyltransferase toxin CDT (Clostridium difficile transferase), which ADP-ribosylates actin and inhibits actin polymerization. Thus far, the role of CDT as a virulence factor is not understood. Here we report by using time-lapse- and immunofluorescence microscopy that CDT and other binary actin-ADP-ribosylating toxins, including Clostridium botulinum C2 toxin and Clostridium perfringens iota toxin, induce redistribution of microtubules and formation of long (up to >150 microm) microtubule-based protrusions at the surface of intestinal epithelial cells. The toxins increase the length of decoration of microtubule plus-ends by EB1/3, CLIP-170 and CLIP-115 proteins and cause redistribution of the capture proteins CLASP2 and ACF7 from microtubules at the cell cortex into the cell interior. The CDT-induced microtubule protrusions form a dense meshwork at the cell surface, which wrap and embed bacterial cells, thereby largely increasing the adherence of Clostridia. The study describes a novel type of microtubule structure caused by less efficient microtubule capture and offers a new perspective for the pathogenetic role of CDT and other binary actin-ADP-ribosylating toxins in host-pathogen interactions.
authors.affiliation: Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Schwan
authors.forename: Bärbel
authors.initials: B
authors.lastname: Stecher
authors.forename: Tina
authors.initials: T
authors.lastname: Tzivelekidis
authors.forename: Marco
authors.initials: M
authors.lastname: van Ham
authors.forename: Manfred
authors.initials: M
authors.lastname: Rohde
authors.forename: Wolf-Dietrich
authors.initials: WD
authors.lastname: Hardt
authors.forename: Jürgen
authors.initials: J
authors.lastname: Wehland
authors.forename: Klaus
authors.initials: K
authors.lastname: Aktories
mesh_terms: D036002:ADP Ribose Transferases / Q000378:metabolism / Q000494:pharmacology* / Q000502:physiology; D008841:Actin Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D001422:Bacterial Adhesion / Q000187:drug effects* / Q000502:physiology; D001427:Bacterial Toxins / Q000378:metabolism / Q000494:pharmacology*; D018938:Caco-2 Cells; D022081:Cell Surface Extensions / Q000187:drug effects* / Q000378:metabolism; D016360:Clostridioides difficile / Q000201:enzymology / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D005856:Germ-Free Life; D019073:HT29 Cells; D006801:Humans; D051379:Mice; D008870:Microtubules / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
chemical_list: D001427:Bacterial Toxins; D036002:ADP Ribose Transferases