title: Accumulation of staphylococcal Panton-Valentine leukocidin in the detergent-resistant membrane microdomains on the target cells is essential for its cytotoxicity.
abstract: The mechanisms for the cytotoxicity of staphylococcal Panton-Valentine leukocidin (PVL), a pore-forming toxin consisting of LukS-PV and LukF-PV, in human immune cells are still unclear. Because LukS-PV binds to ganglioside GM1, a constituent of detergent-resistant membrane microdomains (DRMs) of the plasma membrane, the role of DRMs in PVL cytotoxicity was examined in human polymorphonuclear neutrophils (PMNs), monocytes, HL-60 cells, and THP-1 cells. PVL binding capacities in HL-60 and THP-1 cells were higher than those in PMNs and monocytes; however, the PVL concentration to obtain more than 80% cell lysis in HL-60 cells was 10 times higher than that in PMNs and PVL even at such concentration induced < 10% cell lysis in THP-1 cells. After incubation of PMNs with LukS-PV, more than 90% of LukS-PV bound to the detergent-soluble membranes. Subsequent incubation with LukF-PV at 4 °C induced the accumulation of more than 70% of PVL components and 170- to 220-kDa complex formation in DRMs in an actin-independent manner. However, only 30% of PVL was found, and complex formation was under detectable level in DRMs in HL-60 cells. PVL did not accumulate in DRMs in THP-1 cells. Our observations strongly indicate that PVL accumulation in DRMs is essential for PVL cytotoxicity.
authors.affiliation: Division of Bacteriology, Department of Infectious Disease Control and International Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Akihito
authors.initials: A
authors.lastname: Nishiyama
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Isobe
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Iwao
authors.forename: Tomomi
authors.initials: T
authors.lastname: Takano
authors.forename: Wei-Chun
authors.initials: WC
authors.lastname: Hung
authors.forename: Ikue
authors.initials: I
authors.lastname: Taneike
authors.forename: Saori
authors.initials: S
authors.lastname: Nakagawa
authors.forename: Soshi
authors.initials: S
authors.lastname: Dohmae
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Iwakura
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Yamamoto
mesh_terms: D001427:Bacterial Toxins / Q000032:analysis* / Q000633:toxicity*; D016923:Cell Death; D002478:Cells, Cultured; D005098:Exotoxins / Q000032:analysis* / Q000633:toxicity*; D006801:Humans; D007956:Leukocidins / Q000032:analysis* / Q000633:toxicity*; D021962:Membrane Microdomains / Q000737:chemistry*; D009000:Monocytes / Q000737:chemistry / Q000187:drug effects*; D009504:Neutrophils / Q000737:chemistry / Q000187:drug effects*; D013210:Staphylococcus / Q000472:pathogenicity
chemical_list: D001427:Bacterial Toxins; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin