title: Vizantin inhibits endotoxin-mediated immune responses via the TLR 4/MD-2 complex.
abstract: Vizantin has immunostimulating properties and anticancer activity. In this study, we investigated the molecular mechanism of immune activation by vizantin. THP-1 cells treated with small interfering RNA for TLR-4 abolished vizantin-induced macrophage activation processes such as chemokine release. In addition, compared with wild-type mice, the release of MIP-1β induced by vizantin in vivo was significantly decreased in TLR-4 knockout mice, but not in TLR-2 knockout mice. Vizantin induced the release of IL-8 when HEK293T cells were transiently cotransfected with TLR-4 and MD-2, but not when they were transfected with TLR-4 or MD-2 alone or with TLR-2 or TLR-2/MD-2. A dipyrromethene boron difluoride-conjugated vizantin colocalized with TLR-4/MD-2, but not with TLR-4 or MD-2 alone. A pull-down assay with vizantin-coated magnetic beads showed that vizantin bound to TLR-4/MD-2 in extracts from HEK293T cells expressing both TLR-4 and MD-2. Furthermore, vizantin blocked the LPS-induced release of TNF-α and IL-1β and inhibited death in mice. We also performed in silico docking simulation analysis of vizantin and MD-2 based on the structure of MD-2 complexed with the LPS antagonist E5564; the results suggested that vizantin could bind to the active pocket of MD-2. Our observations show that vizantin specifically binds to the TLR-4/MD-2 complex and that the vizantin receptor is identical to the LPS receptor. We conclude that vizantin could be an effective adjuvant and a therapeutic agent in the treatment of infectious diseases and the endotoxin shock caused by LPS.
authors.affiliation: Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan; Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, 2-5274, Gakkocho-dori, Chuo-ku, Niigata 951-8514, Japan;
authors.forename: Masataka
authors.initials: M
authors.lastname: Oda
authors.affiliation: Department of Chemistry and Functional Molecule, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan;
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Yamamoto
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: Shibutani
authors.affiliation: Department of Chemistry and Functional Molecule, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan;
authors.forename: Mayo
authors.initials: M
authors.lastname: Nakano
authors.affiliation: Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan;
authors.forename: Kenta
authors.initials: K
authors.lastname: Yabiku
authors.affiliation: Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan;
authors.forename: Takafumi
authors.initials: T
authors.lastname: Tarui
authors.affiliation: Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan;
authors.forename: Naoya
authors.initials: N
authors.lastname: Kameyama
authors.affiliation: Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan;
authors.forename: Daiki
authors.initials: D
authors.lastname: Shirakawa
authors.affiliation: Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan;
authors.forename: Sumiyo
authors.initials: S
authors.lastname: Obayashi
authors.affiliation: Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan;
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Watanabe
authors.affiliation: Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan;
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakase
authors.affiliation: Department of Medical Pharmacology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan; and.
authors.forename: Midori
authors.initials: M
authors.lastname: Suenaga
authors.affiliation: Department of Medical Pharmacology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan; and.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Matsunaga
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
authors.affiliation: Institute of Pharmacognosy, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan.
authors.forename: Hironobu
authors.initials: H
authors.lastname: Takahashi
authors.affiliation: Department of Chemistry and Functional Molecule, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan;
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Imagawa
authors.affiliation: Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, 2-5274, Gakkocho-dori, Chuo-ku, Niigata 951-8514, Japan;
authors.forename: Mie
authors.initials: M
authors.lastname: Kurosawa
authors.affiliation: Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, 2-5274, Gakkocho-dori, Chuo-ku, Niigata 951-8514, Japan;
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Terao
authors.affiliation: Department of Chemistry and Functional Molecule, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan;
authors.forename: Mugio
authors.initials: M
authors.lastname: Nishizawa
authors.affiliation: Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan; sakurai@ph.bunri-u.ac.jp.
authors.forename: Jun
authors.initials: J
authors.lastname: Sakurai
mesh_terms: D000818:Animals; D054407:Chemokine CCL4 / Q000096:biosynthesis; D016207:Cytokines / Q000096:biosynthesis; D004731:Endotoxins / Q000276:immunology*; D015870:Gene Expression; D006017:Glycolipids / Q000378:metabolism / Q000494:pharmacology*; D057809:HEK293 Cells; D006801:Humans; D007109:Immunity / Q000187:drug effects* / Q000235:genetics; D018836:Inflammation Mediators / Q000378:metabolism; D008070:Lipopolysaccharides / Q000276:immunology / Q000494:pharmacology; D051218:Lymphocyte Antigen 96 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008264:Macrophages / Q000737:chemistry / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D008958:Models, Molecular; D011485:Protein Binding; D011487:Protein Conformation; D021381:Protein Transport; D051197:Toll-Like Receptor 4 / Q000235:genetics / Q000378:metabolism; D014199:Trehalose / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology
chemical_list: C579729:6,6'-bis-O-(3-nonyldodecanoyl)-alpha,alpha'-trehalose; D054407:Chemokine CCL4; D016207:Cytokines; D004731:Endotoxins; D006017:Glycolipids; D018836:Inflammation Mediators; D008070:Lipopolysaccharides; D051218:Lymphocyte Antigen 96; D051197:Toll-Like Receptor 4; D014199:Trehalose