title: Kudoa septempunctata was recognised by toll-like receptor 2 produced by a RAW 264 macrophage-like cell line.
abstract: Kudoa septempunctata is a myxosporean parasite that infects Paralichthys olivaceus (olive flounder). Previously, we reported that the consumption of raw P. olivaceus meat containing a high concentration of K. septempunctata spores induces transient but severe diarrhoea and emesis. In this study, we investigated the cytokine production of mouse macrophage-like RAW 264 cells stimulated with K. septempunctata. When the RAW 264 cells were incubated with the spores of K. septempunctata for 24 h, they secreted tumour necrosis factor α (TNF-α) and several chemokines, such as IP-10, MIP-1β, and MIP-2. The secretion of TNF-α was induced in a dose-dependent manner in a bioassay using L929 cells and mouse TNF-α-specific enzyme-linked immunosorbent assay (ELISA). To identify the macrophage receptor of K. septempunctata, activation of HEK 293 cells expressing one of the Toll-like receptors (TLR) was measured using an NF-κB-dependent reporter assay. TLR2-expressing HEK 293 cells were strongly activated following stimulation with the spores. These results suggested that K. septempunctata was recognised by TLR2 on the macrophages, which were then activated and produced TNF-α.
authors.affiliation: Division of Microbiology, National Institute of Health Sciences, Setagaya, Tokyo, Japan. ohnisi@nihs.go.jp
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ohnishi
authors.forename: Rie
authors.initials: R
authors.lastname: Oyama
authors.forename: Hiroko
authors.initials: H
authors.lastname: Furusawa
authors.forename: Natsuki
authors.initials: N
authors.lastname: Ohba
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Kamata
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Sugita-Konishi
mesh_terms: D000818:Animals; D002460:Cell Line; D016207:Cytokines / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D008264:Macrophages; D051379:Mice; D055764:Myxozoa / Q000502:physiology*; D051195:Toll-Like Receptor 2 / Q000235:genetics / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism
chemical_list: D016207:Cytokines; C493486:Tlr2 protein, mouse; D051195:Toll-Like Receptor 2; D014409:Tumor Necrosis Factor-alpha