title: Clostridium perfringens α-Toxin Impairs Lipid Raft Integrity in Neutrophils.
abstract: Clostridium perfringens type A, a Gram-positive, anaerobic bacterium, causes gas gangrene. Recently, we reported that C. perfringens α-toxin blocked neutrophil differentiation in an enzyme activity-dependent manner to impair host innate immunity, which should be crucial for the pathogenesis of C. perfringens. However, the detailed mechanism remains unclear. Lipid rafts have been reported to be platforms for signaling molecules involved in the regulation of cell differentiation in many different cell types. In this study, we found that cell surface expression of a lipid raft marker, GM1 ganglioside, decreased in association with neutrophil differentiation by flow cytometry analysis and morphological observation. In vitro treatment of isolated mouse bone marrow cells with α-toxin or an α-toxin variant lacking phospholipase C and sphingomyelinase activities revealed that α-toxin increased the cell surface expression of GM1 ganglioside in an enzyme activity-dependent manner. C. perfringens infection also increased GM1 ganglioside levels in bone marrow myeloid cells. Moreover, treatment of bone marrow cells with methyl-β-cyclodextrin, a lipid raft-disrupting agent, impaired neutrophil differentiation. Together, our results suggest that the integrity of lipid rafts should be properly maintained during granulopoiesis, and α-toxin might perturb lipid raft integrity leading to the impairment of neutrophil differentiation.
authors.affiliation: Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University.
authors.forename: Masaya
authors.initials: M
authors.lastname: Takehara
authors.forename: Teruhisa
authors.initials: T
authors.lastname: Takagishi
authors.forename: Soshi
authors.initials: S
authors.lastname: Seike
authors.forename: Kyohei
authors.initials: K
authors.lastname: Oishi
authors.forename: Yoshino
authors.initials: Y
authors.lastname: Fujihara
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Miyamoto
authors.forename: Keiko
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nagahama
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000494:pharmacology*; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D005677:G(M1) Ganglioside / Q000378:metabolism; D021962:Membrane Microdomains / Q000187:drug effects*; D008810:Mice, Inbred C57BL; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D010738:Type C Phospholipases / Q000494:pharmacology*; D047392:beta-Cyclodextrins / Q000494:pharmacology
chemical_list: D001427:Bacterial Toxins; D002135:Calcium-Binding Proteins; D047392:beta-Cyclodextrins; C108732:methyl-beta-cyclodextrin; D005677:G(M1) Ganglioside; D010738:Type C Phospholipases; C040649:alpha toxin, Clostridium perfringens