title: Microfilament-disrupting Clostridium difficile toxin B causes multinucleation of transformed cells but does not block capping of membrane Ig.
abstract: The effects of Clostridium difficile toxin B on some actin-dependent cellular functions were studied. A three-day incubation of intoxicated B-lymphocytes and transformed 3T3 fibroblasts resulted in dose-dependent multinucleation. Using vimentin-negative Daudi cells we showed that this effect of toxin B does not involve vimentin. As DNA and protein syntheses are not impaired in the cells used, the results suggest that toxin B has an effect on the actin-containing contractile ring during mitosis, in a manner similar to that of the microfilament-disrupting agent cytochalasin B. Toxin B is the first bacterial toxin shown to have this effect. It was also found that the capping of surface IgM on B-lymphocytes was not inhibited by toxin B, whereas cytochalasin B did inhibit capping. These results suggest that capping is dependent on a specific membrane-associated actin structure, which is not affected by toxin B.
authors.affiliation: Department of Bacteriology, Karolinska Institutet, Stockholm/Sweden.
authors.forename: M C
authors.initials: MC
authors.lastname: Shoshan
authors.forename: P
authors.initials: P
authors.lastname: Aman
authors.forename: S
authors.initials: S
authors.lastname: Skog
authors.forename: I
authors.initials: I
authors.lastname: Florin
authors.forename: M
authors.initials: M
authors.lastname: Thelestam
mesh_terms: D008841:Actin Cytoskeleton / Q000187:drug effects / Q000648:ultrastructure*; D000818:Animals; D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D001426:Bacterial Proteins; D001427:Bacterial Toxins / Q000494:pharmacology*; D002461:Cell Line, Transformed; D002467:Cell Nucleus / Q000187:drug effects / Q000648:ultrastructure*; D016360:Clostridioides difficile; D003571:Cytochalasin B / Q000494:pharmacology; D003603:Cytotoxins / Q000494:pharmacology*; D007152:Immunologic Capping / Q000187:drug effects*; D051379:Mice; D014407:Tumor Cells, Cultured
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D003603:Cytotoxins; C031815:toxB protein, Clostridium difficile; D003571:Cytochalasin B