title: Characterization of novel staphylococcal enterotoxin-like toxin type P.
abstract: We investigated the biological properties of a novel staphylococcal enterotoxin (SE)-like toxin type P (SElP). SElP induced a substantial proliferative response and the production of cytokines interleukin-2, gamma interferon, tumor necrosis factor alpha, and interleukin-4 from human T cells when administered at a concentration of 0.4 pM (0.01 ng/ml) or more. The expression of major histocompatibility complex class II molecules on accessory cells was required for T-cell stimulation by SElP. SElP selectively stimulated a vast number of human T cells bearing receptors Vbeta 5.1, 6, 8, 16, 18, and 21.3. These results indicated that SElP acts as a superantigen. SElP proved to be emetic in the house musk shrew emetic assay, although at a relatively high dose (50 to 150 mug/animal). A quantitative assay of SElP production with 30 Staphylococcus aureus strains harboring selp showed that 60% of these strains produced significant amounts of SElP in vitro. All 10 strains carrying seb and selp produced SEB but not SElP, suggesting the inactivation of the selp locus in S. aureus strains with a particular se gene constitution.
authors.affiliation: Department of Veterinary Microbiology, Faculty of Agriculture, Iwate University, Ueda 3-18-8, Morioka, Iwate 020-8550, Japan. omo@iwate-u.ac.jp
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Omoe
authors.forename: Ken'ichi
authors.initials: K
authors.lastname: Imanishi
authors.forename: Dong-Liang
authors.initials: DL
authors.lastname: Hu
authors.forename: Hidehito
authors.initials: H
authors.lastname: Kato
authors.forename: Yoshitaku
authors.initials: Y
authors.lastname: Fugane
authors.forename: Yohei
authors.initials: Y
authors.lastname: Abe
authors.forename: Shoji
authors.initials: S
authors.lastname: Hamaoka
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Akio
authors.initials: A
authors.lastname: Nakane
authors.forename: Takehiko
authors.initials: T
authors.lastname: Uchiyama
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Shinagawa
mesh_terms: D000818:Animals; D004768:Enterotoxins / Q000008:administration & dosage / Q000737:chemistry* / Q000235:genetics / Q000276:immunology; D006801:Humans; D008214:Lymphocytes / Q000276:immunology; D013211:Staphylococcus aureus / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification / Q000472:pathogenicity*; D018089:Superantigens / Q000008:administration & dosage / Q000737:chemistry / Q000235:genetics* / Q000276:immunology
chemical_list: D004768:Enterotoxins; C504429:SEIP protein, Staphylococcus aureus; D018089:Superantigens