title: Critical contribution of IFN-gamma and NK cells, but not perforin-mediated cytotoxicity, to anti-metastatic effect of alpha-galactosylceramide.
abstract: The glycolipid alpha -galactosylceramide (alpha -GalCer), which is presented by CD1d and specifically activates Valpha 14 NKT cells, exerts a potent anti-metastatic effect when administered in vivo. In this study, we demonstrated that alpha -GalCer administration led to rapid elimination of NKT cells by apoptosis in the liver and spleen, after they produced IFN-gamma and IL-4. In contrast, a more prolonged secretion of IFN-gamma was observed by liver and splenic NK cells after alpha -GalCer administration. Cytotoxic activity of liver mononuclear cells was not augmented 3h after alpha -GalCer administration, but was increased at 24 h when NKT cells were mostly depleted. The alpha -GalCer-induced cytotoxic activity was abolished in IFN-gamma -deficient and NK cell-depleted mice as well as CD1-deficient mice, suggesting that the alpha -Galcer-induced cytotoxicity was mainly mediated by IFN-gamma -activated NK cells. While the alpha -GalCer-induced cytotoxicity in vitro was mostly perforin dependent, anti-metastatic effect of alpha -GalCer was impaired in NK cell-depleted or IFN-gamma -deficient mice but not in perforin-deficient mice. Collectively, these results indicated that the anti-metastatic effect of alpha -GalCer is mainly mediated by NK cells, which are activated secondarily by IFN-gamma produced by alpha -GalCer-activated NKT cells, in a perforin-independent manner.
authors.affiliation: Department of Pathogenic Biochemistry, Research Institute of Natural Medicine, Toyama Medical and Pharmaceutical University, Toyama, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Hayakawa
authors.forename: K
authors.initials: K
authors.lastname: Takeda
authors.forename: H
authors.initials: H
authors.lastname: Yagita
authors.forename: S
authors.initials: S
authors.lastname: Kakuta
authors.forename: Y
authors.initials: Y
authors.lastname: Iwakura
authors.forename: L
authors.initials: L
authors.lastname: Van Kaer
authors.forename: I
authors.initials: I
authors.lastname: Saiki
authors.forename: K
authors.initials: K
authors.lastname: Okumura
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000276:immunology; D003602:Cytotoxicity, Immunologic / Q000276:immunology*; D005699:Galactosylceramides / Q000494:pharmacology*; D007371:Interferon-gamma / Q000096:biosynthesis / Q000276:immunology*; D015847:Interleukin-4 / Q000096:biosynthesis; D007694:Killer Cells, Natural / Q000187:drug effects* / Q000276:immunology*; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009362:Neoplasm Metastasis / Q000517:prevention & control*; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D013601:T-Lymphocytes / Q000276:immunology; D013997:Time Factors
chemical_list: D000970:Antineoplastic Agents; D005699:Galactosylceramides; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D054353:Perforin; D015847:Interleukin-4; D007371:Interferon-gamma