title: Immunosuppressive effect of shedding intercellular adhesion molecule 1 antigen on cell-mediated cytotoxicity against tumor cells.
abstract: We have examined whether shedding intercellular adhesion molecule-1 (ICAM-1) antigen from cultured tumors is able to inhibit the leukocyte function-associated antigen-1 (LFA-1)/ICAM-1 interaction between cytotoxic effector cells and ICAM-1+ target tumor cells. The cytotoxic activity of lymphokine-activated killer (LAK) cells incubated with spent media from ICAM-1+ tumor cells, especially interferon-gamma-stimulated tumor cells, was significantly decreased as compared with that of LAK cells treated with fresh culture medium without ICAM-1 antigen. Treatment of LAK cells with spent media from ICAM-1- tumor cells did not cause a significant decrease of the cytolytic activity towards ICAM-1+ tumor cells. These findings suggest that shedding of ICAM-1 antigen could be involved in binding of LFA-1 to LAK cells, resulting in reduced cytolytic activity.
authors.affiliation: Department of Internal Medicine, University of Tsukuba, Ibaraki.
authors.forename: S
authors.initials: S
authors.lastname: Koyama
mesh_terms: D015703:Antigens, CD / Q000276:immunology; D000951:Antigens, Neoplasm / Q000276:immunology; D015815:Cell Adhesion Molecules / Q000276:immunology*; D017077:Culture Media, Conditioned; D003602:Cytotoxicity, Immunologic / Q000276:immunology*; D015536:Down-Regulation; D005455:Fluorescent Antibody Technique; D005706:Gallbladder Neoplasms / Q000276:immunology; D006801:Humans; D007157:Immunologic Surveillance / Q000276:immunology*; D018799:Intercellular Adhesion Molecule-1; D007371:Interferon-gamma / Q000494:pharmacology; D015979:Killer Cells, Lymphokine-Activated / Q000276:immunology* / Q000378:metabolism; D016169:Lymphocyte Function-Associated Antigen-1 / Q000276:immunology* / Q000378:metabolism; D009369:Neoplasms / Q000276:immunology*; D013274:Stomach Neoplasms / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000276:immunology
chemical_list: D015703:Antigens, CD; D000951:Antigens, Neoplasm; D015815:Cell Adhesion Molecules; D017077:Culture Media, Conditioned; D016169:Lymphocyte Function-Associated Antigen-1; D018799:Intercellular Adhesion Molecule-1; D007371:Interferon-gamma