title: Interleukin-12 and interleukin-18 change ICAM-I expression, and enhance natural killer cell mediated cytolysis of human osteosarcoma cells.
abstract: Cytokines play important roles in the expression of adhesion molecules and the function of anti-tumor effector cells in the immune system. In this study, the influence of interleukin-12 (IL-12) and IL-18 on the expression of ICAM-1 and natural killer (NK)-cell mediated lysis in a human osteosarcoma cell line (HOS) was evaluated. ICAM-I expression of HOS cells were analyzed by flow cytometry following treatment with IL-12, IL-18 or both, and in co-cultures with peripheral lymphocytes. NK-cell activation in response to IL-12 and IL-18 was investigated by selective flow cytometry using propidium iodide. ICAM-1 expression on HOS cells was significantly enhanced by IL-12, but only when co-cultured in cell-to-cell contact with peripheral lymphocytes. Antibodies to interferon-gamma abrogated this effect. If HOS cells and peripheral lymphocytes were separated in co-cultures, IL-18 could substitute for cell-to-cell contact, facilitating IL-12-mediated enhancement of ICAM-1. Addition of IL-18 also enhanced NK-mediated cytolysis of HOS cells. These findings demonstrate that IL-12 can enhance the expression of ICAM-1 in the presence of IFN-gamma and, with IL-18, enhances NK anti-tumor activity. Immunomodulation via cytokine therapy may lead to improved eradication of chemotherapy-resistant osteosarcomas.
authors.affiliation: Department of Orthopaedic Surgery Ernst-Moritz-Arndt University Greifswald, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Liebau
authors.forename: Harry
authors.initials: H
authors.lastname: Merk
authors.forename: Sebastian
authors.initials: S
authors.lastname: Schmidt
authors.forename: Christian
authors.initials: C
authors.lastname: Roesel
authors.forename: Christiaan
authors.initials: C
authors.lastname: Karreman
authors.forename: Johannes Bernd
authors.initials: JB
authors.lastname: Prisack
authors.forename: Hans
authors.initials: H
authors.lastname: Bojar
authors.forename: Axel W A
authors.initials: AW
authors.lastname: Baltzer
mesh_terms: D045744:Cell Line, Tumor; D018920:Coculture Techniques; D005434:Flow Cytometry; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism*; D007371:Interferon-gamma / Q000378:metabolism; D018664:Interleukin-12 / Q000378:metabolism*; D020382:Interleukin-18 / Q000378:metabolism*; D007694:Killer Cells, Natural / Q000378:metabolism*; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008214:Lymphocytes / Q000378:metabolism; D012516:Osteosarcoma / Q000378:metabolism*; D011419:Propidium / Q000494:pharmacology; D015854:Up-Regulation
chemical_list: D020382:Interleukin-18; D018799:Intercellular Adhesion Molecule-1; D018664:Interleukin-12; D011419:Propidium; D007371:Interferon-gamma