title: Susceptibility of natural killer (NK) cells to reactive oxygen species (ROS) and their restoration by the mimics of superoxide dismutase (SOD).
abstract: Natural killer (NK) cells are susceptible to reactive oxygen species (ROS), and lose the activity by the effects of ROS. Cancer bearing hosts usually suffer from oxidative stress (OS), and the NK-activity decreases to a significantly lower level than normal controls. Superoxide dismutase (SOD)-mimicking substances, such as protein-bound polysaccharide of Coriolus versicolor (Fr) QUEL (PSK) and iron-chelating chlorine e6-Na (FeCNa), can restore the NK-activity of cancer bearing hosts, when collaborating with catalase. Incorporation of 3H-thymidine by ROS-treated NK-cells is not affected, indicating that these cells are still active in the nucleic acid metabolism. Intraperitoneal administration of anti-Asialo GM1 antibody extinguished the NK-activity. NK-cells affected by ROS lost the adherence to target cancer cells in both in vitro and in vivo. ROS may change the surface charge of NK-cells to anionic, resulting in an inability of adhesion to target cancer cells which usually show the negative surface charge.
authors.affiliation: Department of Biochemistry, Kitasato University School of Medicine, Kanagawa, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nakamura
authors.forename: K
authors.initials: K
authors.lastname: Matsunaga
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology* / Q000627:therapeutic use; D002279:Carcinoma 256, Walker / Q000188:drug therapy / Q000276:immunology*; D002417:Cattle; D004912:Erythrocytes / Q000201:enzymology; D005260:Female; D007155:Immunologic Factors / Q000494:pharmacology* / Q000627:therapeutic use; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology*; D018384:Oxidative Stress / Q000502:physiology*; D011509:Proteoglycans / Q000494:pharmacology* / Q000627:therapeutic use; D051381:Rats; D011919:Rats, Inbred Strains; D017382:Reactive Oxygen Species / Q000276:immunology*; D013482:Superoxide Dismutase / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D000903:Antibiotics, Antineoplastic; D007155:Immunologic Factors; D011509:Proteoglycans; D017382:Reactive Oxygen Species; C010770:polysaccharide-K; D013482:Superoxide Dismutase