title: Cancer immunoediting by GITR (glucocorticoid-induced TNF-related protein) ligand in humans: NK cell/tumor cell interactions.
abstract: Glucocorticoid-induced TNF-related protein (GITR) has been shown to stimulate T cell-mediated antitumor immunity in mice. However, the functional relevance of GITR and its ligand (GITRL) for non-T cells has yet to be fully explored. In addition, recent evidence suggests that GITR plays different roles in mice and humans. We studied the role of GITR-GITRL interaction in human tumor immunology and report for the first time that primary gastrointestinal cancers and tumor cell lines of different histological origin express substantial levels of GITRL. Signaling through GITRL down-regulated the expression of the immunostimulatory molecules CD40 and CD54 and the adhesion molecule EpCAM, and induced production of the immunosuppressive cytokine TGF-beta by tumor cells. On NK cells, GITR is constitutively expressed and up-regulated following activation. Blocking GITR-GITRL interaction in cocultures of tumor cells and NK cells substantially increased cytotoxicity and IFN-gamma production of NK cells demonstrating that constitutive expression of GITRL by tumor cells diminishes NK cell antitumor immunity. GITRL-Ig fusion protein or cell surface-expressed GITRL did not induce apoptosis in NK cells, but diminished nuclear localized c-Rel and RelB, indicating that GITR might negatively modulate NK cell NF-kappaB activity. Taken together, our data indicate that tumor-expressed GITRL mediates immunosubversion in humans.
authors.affiliation: Department of Internal Medicine, Eberhard-Karls University, Otfried-Mueller-Str. 10, D-72076 Tuebingen, Germany.
authors.forename: Katrin M
authors.initials: KM
authors.lastname: Baltz
authors.forename: Matthias
authors.initials: M
authors.lastname: Krusch
authors.forename: Anita
authors.initials: A
authors.lastname: Bringmann
authors.forename: Peter
authors.initials: P
authors.lastname: Brossart
authors.forename: Frank
authors.initials: F
authors.lastname: Mayer
authors.forename: Mercedes
authors.initials: M
authors.lastname: Kloss
authors.forename: Tina
authors.initials: T
authors.lastname: Baessler
authors.forename: Ingrid
authors.initials: I
authors.lastname: Kumbier
authors.forename: Andrea
authors.initials: A
authors.lastname: Peterfi
authors.forename: Susan
authors.initials: S
authors.lastname: Kupka
authors.forename: Stefan
authors.initials: S
authors.lastname: Kroeber
authors.forename: Dagmar
authors.initials: D
authors.lastname: Menzel
authors.forename: Markus P
authors.initials: MP
authors.lastname: Radsak
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Rammensee
authors.forename: Helmut R
authors.initials: HR
authors.lastname: Salih
mesh_terms: D000818:Animals; D019556:COS Cells; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D053450:Glucocorticoid-Induced TNFR-Related Protein; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D008024:Ligands; D009369:Neoplasms / Q000276:immunology*; D017475:Receptors, Nerve Growth Factor / Q000235:genetics / Q000502:physiology*; D018124:Receptors, Tumor Necrosis Factor / Q000235:genetics / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014162:Transfection; D048069:Tumor Necrosis Factors / Q000235:genetics / Q000502:physiology*
chemical_list: D053450:Glucocorticoid-Induced TNFR-Related Protein; D008024:Ligands; D017475:Receptors, Nerve Growth Factor; D018124:Receptors, Tumor Necrosis Factor; D011993:Recombinant Fusion Proteins; C491405:TNFRSF18 protein, human; C478967:TNFSF18 protein, human; D048069:Tumor Necrosis Factors