title: Clostridium perfringens Delta-Toxin Induces Rapid Cell Necrosis.
abstract: Clostridium perfringens delta-toxin is a β-pore-forming toxin and a putative pathogenic agent of C. perfringens types B and C. However, the mechanism of cytotoxicity of delta-toxin remains unclear. Here, we investigated the mechanisms of cell death induced by delta-toxin in five cell lines (A549, A431, MDCK, Vero, and Caco-2). All cell lines were susceptible to delta-toxin. The toxin caused rapid ATP depletion and swelling of the cells. Delta-toxin bound and formed oligomers predominantly in plasma membrane lipid rafts. Destruction of the lipid rafts with methyl β-cyclodextrin inhibited delta-toxin-induced cytotoxicity and ATP depletion. Delta-toxin caused the release of carboxyfluorescein from sphingomyelin-cholesterol liposomes and formed oligomers; toxin binding to the liposomes declined with decreasing cholesterol content in the liposomes. Flow cytometric assays with annexin V and propidium iodide revealed that delta-toxin treatment induced an elevation in the population of annexin V-negative and propidium iodide-positive cells. Delta-toxin did not cause the fragmentation of DNA or caspase-3 activation. Furthermore, delta-toxin caused damage to mitochondrial membrane permeability and cytochrome c release. In the present study, we demonstrate that delta-toxin produces cytotoxic activity through necrosis.
authors.affiliation: Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan.
authors.forename: Soshi
authors.initials: S
authors.lastname: Seike
authors.affiliation: Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Miyamoto
authors.affiliation: Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Kobayashi
authors.affiliation: Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan.
authors.forename: Masaya
authors.initials: M
authors.lastname: Takehara
authors.affiliation: Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nagahama
mesh_terms: D000818:Animals; D001427:Bacterial Toxins; D018938:Caco-2 Cells; D053148:Caspase 3 / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects*; D002522:Chlorocebus aethiops; D053938:DNA Fragmentation / Q000187:drug effects; D005452:Fluoresceins / Q000378:metabolism; D006801:Humans; D021962:Membrane Microdomains / Q000187:drug effects / Q000378:metabolism; D009336:Necrosis / Q000139:chemically induced* / Q000378:metabolism; D014709:Vero Cells
chemical_list: D001427:Bacterial Toxins; C029352:Clostridium perfringens delta-toxin; D005452:Fluoresceins; C024098:6-carboxyfluorescein; D053148:Caspase 3