title: Interleukin-12- and interferon-gamma-mediated natural killer cell activation by Agaricus blazei Murill.
abstract: Dried fruiting bodies of Agaricus blazei Murill (A. blazei) and its extracts have generally used as complementary and alternative medicines (CAMs). Here, we report that the oral administration of A. blazei augmented cytotoxicity of natural killer (NK) cells in wild-type (WT) C57BL/6, C3H/HeJ, and BALB/c mice. Augmented cytotoxicity was demonstrated by purified NK cells from treated wild-type (WT) and RAG-2-deficient mice, but not from interferon-gamma (IFN-gamma) deficient mice. NK cell activation and IFN-gamma production was also observed in vitro when dendritic cell (DC)-rich splenocytes of WT mice were coincubation with an extract of A. blazei. Both parameters were largely inhibited by neutralizing anti-interleukin-12 (IL-12) monoclonal antibody (mAb) and completely inhibited when anti-IL-12 mAb and anti-IL-18 mAb were used in combination. An aqueous extract of the hemicellulase-digested compound of A. blazei particle; (ABPC) induced IFN-gamma production more effectively, and this was completely inhibited by anti-IL-12 mAb alone. NK cell cytotoxicty was augmented with the same extracts, again in an IL-12 and IFN-gamma-dependent manner. These results clearly demonstrated that A. blazei and ABPC augmented NK cell activation through IL-12-mediated IFN-gamma production.
authors.affiliation: Department of Immunology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Eri
authors.initials: E
authors.lastname: Yuminamochi
authors.forename: Taisuke
authors.initials: T
authors.lastname: Koike
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Takeda
authors.forename: Isao
authors.initials: I
authors.lastname: Horiuchi
authors.forename: Ko
authors.initials: K
authors.lastname: Okumura
mesh_terms: D000364:Agaricus / Q000276:immunology*; D000818:Animals; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology; D007371:Interferon-gamma / Q000096:biosynthesis / Q000276:immunology*; D018664:Interleukin-12 / Q000276:immunology*; D007694:Killer Cells, Natural / Q000276:immunology*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D013154:Spleen / Q000276:immunology
chemical_list: D018664:Interleukin-12; D007371:Interferon-gamma