title: Tumor cells loaded with alpha-galactosylceramide induce innate NKT and NK cell-dependent resistance to tumor implantation in mice.
abstract: Dendritic cells (DCs) loaded with alpha-galactosylceramide (alpha-GalCer) are known to be active APCs for the stimulation of innate NKT and NK cell responses in vivo. In this study, we evaluated the capacity of non-DCs to present alpha-GalCer in vitro and in vivo, particularly tumor cells loaded with alpha-GalCer (tumor/Gal). Even though the tumor cells lacked expression of CD40, CD80, and CD86 costimulatory molecules, the i.v. injection of tumor/Gal resulted in IFN-gamma secretion by NKT and NK cells. These innate responses to tumor/Gal, including the induction of IL-12p70, were comparable to or better than alpha-GalCer-loaded DCs. B16 melanoma cells that were stably transduced to express higher levels of CD1d showed an increased capacity relative to wild-type B16 cells to present alpha-GalCer in vivo. Three different tumor cell lines, when loaded with alpha-GalCer, failed to establish tumors upon i.v. injection, and the mice survived for at least 6 mo. The resistance against tumor cells was independent of CD4 and CD8 T cells but dependent upon NKT and NK cells. Mice were protected from the development of metastases if the administration of live B16 tumor cells was followed 3 h or 3 days later by the injection of CD1d(high)-alpha-GalCer-loaded B16 tumor cells with or without irradiation. Taken together, these results indicate that tumor/Gal are effective APCs for innate NKT and NK cell responses, and that these innate immune responses are able to resist the establishment of metastases in vivo.
authors.affiliation: Research Unit for Cellular Immunotherapy, RIKEN Research Center for Allergy and Immunology, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan.
authors.forename: Kanako
authors.initials: K
authors.lastname: Shimizu
authors.forename: Akira
authors.initials: A
authors.lastname: Goto
authors.forename: Mikiko
authors.initials: M
authors.lastname: Fukui
authors.forename: Masaru
authors.initials: M
authors.lastname: Taniguchi
authors.forename: Shin-ichiro
authors.initials: S
authors.lastname: Fujii
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000276:immunology; D045744:Cell Line, Tumor; D003713:Dendritic Cells / Q000276:immunology*; D005260:Female; D005699:Galactosylceramides / Q000276:immunology*; D006084:Graft Rejection / Q000276:immunology; D007113:Immunity, Innate; D007371:Interferon-gamma / Q000276:immunology; D018664:Interleukin-12 / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D009368:Neoplasm Transplantation / Q000276:immunology; D009374:Neoplasms, Experimental / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D015703:Antigens, CD; D005699:Galactosylceramides; C493154:alpha-galactosylceramide; D018664:Interleukin-12; D007371:Interferon-gamma